This PDF file contains the front matter associated with SPIE Proceedings Volume 12164 including the Title Page, Copyright information, and Table of Contents.

Electronic textiles, also known as smart textiles or smart fabrics, are one of the most promising form factors that enable electronics to be embedded in themselves, offering exceptional physical flexibility and unique size that are unachieved by other techniques. The textile-based sensor has already been a prominent candidate for sensing platform since it can be lightweight, comfortable, as well as easily incorporated into modern garments in a breathable and conformable way. In this review article, we initially summarize the distinctive superiorities of textile-based sensors. For example, they are often used for monitoring purposes in the medical context. Besides, they can also protect the privacy of the user since it is unobtrusive and indistinguishable from the textile itself. Moreover, they can take the measurement at the place where the signal is strongest. Later, the characteristics and recent advances of optical, piezoresistive, piezoelectric, inductive, capacitive textile-based sensors are discussed based on the related working mechanisms and application. Additionally, a concise outline of the state-of-the-art achievements of textile-based sensors is demonstrated. Lastly, the present-day challenges in the development and forward-looking prospects are highlighted. These results shed light for more suitable choices drawn by scholars who intention to research textile sensor technology.

The ripeness of fruits is commonly assessed by the visual appearance, but this method is not very accurate and there can be a large variability. We have developed a hand-held sensor based on laser-induced fluorescence to provide more objective guidance. The instrument incorporates a 412 nm continuous wave semiconductor laser and a miniature spectrometer. It was used for monitoring of tropical fruits growing on the tree, and high-quality spectra could be recorded at ranges of 1-2 meters. The spectra feature characteristic dual-peaked emission peaks in the near-IR region due to chlorophyll, as well as blue-green signals due to further pigments. Further, natural waters were studied and showed strong differentiation effects.

There are many problems in aquaculture and surface water monitoring, such as difficulty in real-time measurement, difficulty in tracking water pollution source and lack of multi-parameter miniaturized rapid detection equipment. Based on photoelectric detection technology, combined with the principle of light scattering and absorption, using four different wavelength LED light sources, an integrated online multi-parameter water quality monitoring module has been developed. Through highly integrated light path design and light source multiplexing, we overcame the interference caused by turbidity and chromaticity, which has the greatest impact on chemical oxygen demand (COD) detection in water quality detection. By optimizing the design of software and hardware, we used an open detection chamber design to overcome the problems of bubbles in common closed chambers. It realized the rapid measurement of COD, turbidity, chromaticity and total dissolved solids (TDS) in water. The experimental results showed that the correlation coefficients between the measured values and their true values of COD, turbidity and chroma in the standard solution were all above 0.98. The measurement results were in good agreement with the actual values. To sum up, the module is highly integrated, convenient for multi-point online deployment, and can realize rapid real-time monitoring of multiple parameters in the water. It provides new technical means for real-time monitoring of water quality and traceability of pollutants in the water.

In order to overcome the shortcomings of poor stability of existing electrode materials, a salinity sensor based on borondoped diamond film (BDD) electrodes is designed in this paper. The electrode of the salinity sensor has excellent characteristics such as wide electrochemical window, large background current, high mechanical strength, corrosion resistance, etc., which can improve the stability and accuracy of the conductivity cell measurement, which is very important for the field of ocean salinity measurement significance. In this paper, based on the measurement principle of the sevenelectrode sensor and the preparation of the diamond film probe, the conductivity cell is studied and designed, the measurement circuit is analyzed and the design of low power consumption is carried out, and then the calibration and fitting of the seven-electrode conductivity sensor are carried out. Finally, data analysis is used to verify that the sensor has achieved stable, reliable, and high-precision measurement performance.

In recent years, metal halide perovskite materials have received extensive attention due to their strong X-ray absorption capacity, high sensitivity, and low-cost preparation1 . In this work, cesium silver bismuth bromide (Cs₂AgBiBr₆) perovskite based detectors were simulated by using drift-diffusion equation in Silvaco. The X-ray energy spectrum was calculated according to the open-source TASMICS algorithm provided by J.H. Siewerdsen² . The perovskite mass energy attenuation coefficients acquired from the NIST database³ were converted into imaginary parts of material refractive index. According to the simulation results, the average photo-current density of Cs₂AgBiBr₆ perovskite material is 10^-9A/cm² compared to Si (10^-10A/cm² ) and α-Se (10¹¹/cm² ). This is due to the relatively large atomic number of Cs₂AgBiBr₆ material and a high carrier mobility lifetime product. In addition, the Cs₂AgBiBr₆ photodetector exhibits a high photocurrent-to-dark current ratio (PDR) of 9700 than Si (51), while α-Se has the largest PDR value of 1.4301×10⁵ . In summary, Both Cs₂AgBiBr₆ and α-Se can be used as the ideal direct X-ray detector materials.

Infrared spectroscopy can provide fingerprints of most molecular compounds, which is widely used for detection of solid, liquid, and gas components with the advantages of fast response, high sensitivity, and specificity. However, Fourier transform infrared spectroscopy (FTIR) system has a large size and is heavy in quality, which limits its potential for onsite detection applications. With the development of materials and technology, quantum cascade laser (QCL), as a kind of infrared coherent light source, has gradually appeared on the market, which provides the possibility to design a portable infrared spectroscopy system with the features of light weight and low cost. Therefore, based on the miniaturized QCL and infrared detector, we designed a portable infrared spectroscopy detection system with a bandwidth of 200 cm^-1 (1168- 952 cm^-1) in this paper. We successfully detected the infrared absorption characteristic peak of ethanol gas at 1060 cm^-1 with this system, which verified its feasibility for detecting infrared spectroscopy of molecular compounds.

High-sensitivity and rapid detection of heavy metal elements in water is in great demand. Traditional laboratory analysis methods limited to long cycles, complex processing, and risk of secondary pollution, which made it impossible to achieve on-site detection. Laser-induced breakdown spectroscopy (LIBS) has the characteristics of rapid and minimal damage and has been applied to the detection of solids, liquids and even gases. However, it is difficult to directly detect with LIBS due to the low content of heavy metals in water and the matrix effect of samples. We propose a rapid detection method of heavy metal elements in water by laser-induced breakdown spectroscopy combined with sample morphology constrained positioning. Using Pb as a representative element, analyze the enhancement effect and mechanism of the above sample processing method on the LIBS signal, and establish a calibration curve with a concentration range of 100-1000 ug/L. The correlation coefficient R2 is 0.97, and the detection limit reaches 86.6 ug/L., which meets the requirements of surface water quality testing. The study combined with portable LIBS equipment can provide a low-cost and rapid screening method for heavy metal pollution in surface water.

Polyvinylidene fluoride (PVDF) is the most widely used flexible piezoelectric material, but its piezoelectric performance is relatively weak compared with piezoelectric ceramics. In order to improve the piezoelectric properties, ZnO nanoarrays/polyvinylidene fluoride-hexafluoropropylene(PVDF-HFP) hybrid piezoelectric nanogenerators were prepared. ZnO nanoarrays were adjustable with different hydrothermal time. The results showed that when the hydrothermal time was 12 h, the length of ZnO nanoarrays with uniform and compact arrangement was about 4 μm to 5 μm, which maximized the performance improvement of the nanogenerators. The applications of the hybrid nanogenerators were explored in touch alarm system and finger bending detection.

In order to enhance the output power of thulium-doped double-cladding fiber laser, the pumping absorption characteristics of fibers with different inner cladding shapes and core diameters were numerically simulated. The results showed that the pump absorption efficiency was as much as 92% when the reflection times N=50 for the novel inner cladding shape.While N=100, the pumping efficiency was as high as 99%. Based on this, the regular hexagon inner cladding and the novel inner cladding were used as working materials in the experiment, respectively. The output power of 13.2 W and 14.8 W were obtained which improved by 12.1%, and the slope efficiency was 31% and 35%, respectively. It is shown that the novel inner cladding fiber is more conducive to the realization of high efficiency pump absorption.

A procedure for spectral reflectance recovery from CIE tristimulus values is proposed using the convolutional neural network method. Unlike the common spectral recovery methods in a linear way, the nonlinear transformation from the CIE tristimulus values to spectral reflectance is to achieve in this paper. In consideration of the computation time and accuracy of spectral recovery, the internal parameters of convolutional neural network are adjusted by the number of neurons and the interval between neurons. The effectiveness of the proposed method and the previous methods are analyzed by calculating the spectral recovery accuracy under different spectral datasets and different error metrics. The results show that the proposed method is superior to traditional algorithms.

A frequency swept source optical coherence tomography (OCT) imaging system is proposed. The frequency swept source used in the system is a Fourier-domain mode-locked (FDML) laser which has a narrow instantaneous linewidth due to the nonlinear spectrum narrowing effect generated by the nonlinear semiconductor optical amplifier (SOA) used in the FDML laser ring cavity. Therefore, the OCT imaging system has the ability to achieve a large imaging depth. The concept is verified in the experiment, which demonstrates a clear two-dimensional target image and a large imaging depth up to 14 mm.

Ultrasound cell delivery has been intensively studied in the context of eukaryotic transformation and gene therapy in recent years. Most existing ultrasound DNA delivery techniques reported used macro volumes with conventional ultrasonic equipment like ultrasonic immersion horns or ultrasonic baths and the cell studies were carried out at population levels where only average analysis is possible (10⁵ –10⁷ cells). However, averaging the effects from cell-cycle-dependent states and inhomogeneous cellular responses contributes to difficulties in interpreting data. New technologies and devices that enable single-cell handling, precision analysis and ultra-sensitive detection are required. A MEMS ultrasound cell delivery device promising a lab-on-chip approach to ultrasound cell delivery has been proposed in this paper. To analytically prove the feasibility of this approach, the piezo-acoustic coupling modelling of the system has been carried out using COMSOL multiphysics and both its acoustics and MEMS modules. The output of the simulation result is very close to the analytical results in both the profile of the acoustic pressure distribution and peak values.

For the comprehensive benefit evaluation of photovoltaic power generation, this paper puts forward a corresponding evaluation model. In order to avoid the influence of human subjective factors, the entropy method is used to modify the weights that determine the relative importance of the indicators at each level of the indicator system by the analytic hierarchy process (AHP). Then, through the matter-element extension model, the comprehensive benefits of photovoltaic power generation projects are comprehensively and systematically analyzed from four aspects: economic benefits, technical benefits, social benefits and environmental benefits. Finally, the comprehensive benefit evaluation of a 30MW photovoltaic power generation project is carried out, and the corresponding conclusions are drawn, which verifies the validity of the model, and provides a method for objectively evaluating the comprehensive benefits of photovoltaic power generation.

Particles are used in a wide range of real-life applications, involving aviation, chemical, energy, medical, metallurgical, meteorological and other fields. Radiation heat transfer is the main heat transfer mode of particles, so the premise of particle utilization is the study of their thermal radiation properties. This paper summarizes the methods for solving the radiation properties of particles by combining the research results of recent years, and finally, by summarizing the existing results, points out the shortcomings in the existing research and the directions that can be further researched in the future

The induction effect of air gap discharge induced by ultrashort pulse laser will be affected by the characteristics of laser ionization filamentation. In order to study the spatial characteristics of ultrashort pulse laser ionization filamentation and propagation. Firstly, an experimental platform for studying the spatial characteristics of ultrashort pulse laser ionization filamentation and propagation is established. Then the axial and radial high-resolution optical images of filaments under the conditions of different focal length auxiliary focusing lens are obtained by using the combination of axial and radial detection method. The effectiveness of this observation method is proved by contrasting with the self-focusing and multiple filament correlation theory. By analyzing the relationship between the filament diameter and the laser propagation distance under the condition of 1m and 5m focal length lens assisted focusing, the effects of micro focusing and tight focusing on the filament distance are obtained. The experimental results show that the filament will continue to travel forward for a certain distance with the minimum optical diameter after reaching the minimum optical diameter in the micro focusing mode. So we can obtain a stable plasma channel in this way; In the tight focusing mode, the defocus effect of plasma plays a leading role in the laser propagation process faster. So the filament will disappear rapidly after reaching the minimum optical diameter, which is not conducive to the long-distance filament transmission.

Nitrate is widely distributed in various water environments, and its potential toxicity poses a great threat to human health and environment. It is of great significance to realize rapid detection of nitrate in water. Raman spectroscopy, as a molecular spectrum, has been widely used in the detection of ionic concentration in liquid samples. However, fluorescence background interference and spectral peak overlap are still a challenge for the detection of trace targets in practical applications. In this study, we proposed a rapid detection method for nitrate at low concentration in drinking water based on Raman spectra combined with adsorption materials., The difference between characteristic spectrum of nitrate adsorption at low concentration and background spectrum of adsorption material was emphatically analyzed after verifying the effectiveness of nitrate adsorbent. The peak decomposition method of nitrate characteristic spectrum was established to achieve highly sensitive detection of nitrate concentration of 5-10 mg/L. The calibration curve of NO₃ - -N concentration in 5-100 mg/L was established according to the normalized spectral intensity. The correlation coefficient R² of the established regression model reached 0.98. The root mean square error (RMSE) was 3.56 mg/L. This study provides a rapid detection method for nitrate in water, which can provide a low-cost assessment method for daily household drinking water quality and water quality purification combined with portable Raman spectrometer. At the same time, this method is also expected to achieve fast on-site detection for early warning response of surface water pollution.

In the digital signal processing, in order to realize the automatic updating of the filter weight coefficient, this paper adopts an adaptive filter based on Cyclone IV EP4CE6 series FPGA to realize LMS algorithm to solve this problem. This paper analyzes the basic principle of the minimum mean square error (LMS) adaptive algorithm and the peripheral hardware circuit. The high parallelism and high computing performance of the FPGA ensure the convergence and stability of the algorithm in this scheme. The simulation results of MATLAB and Modelsim and the measured waveforms of the oscilloscope show that the design can be applied to the actual digital signal system smoothly.

In this paper, ATP-EMTP program is used to build a neutral ungrounded ferroresonance overvoltage electromagnetic transient simulation model according to a 110V/35kV substation, and the variation law of ferroresonance overvoltage and overcurrent when single phase grounding occurs in the system is analyzed. The effect of damping measures, such as open triangular winding connecting damping resistance, PT high voltage side connecting damping resistance grounding, and system neutral connecting are suppression coil, on ferromagnetic resonance suppression are simulated and compared, and their advantages and disadvantages are summarized. The results can provide necessary reference for the study of ferromagnetic resonance overvoltage suppression measures in power grid.

The fuel cell-battery hybrid ship uses fuel cells as the main power source and batteries as the auxiliary power source. For hybrid power systems, an energy management strategy (EMS) is needed to allocate the output power of each power source. In order to improve hydrogen fuel economy and system life, an external energy efficiency maximization strategy based on power decoupling is proposed for simulation analysis, and compare with the dual closed-loop PI control strategy and the traditional external energy efficiency maximization strategy (EEMS) to verify its effectiveness. The results show that the proposed strategy can meet the power requirements of ships under typical working conditions, effectively reduce hydrogen fuel consumption, and increase the utilization rate of batteries, thereby using the characteristics of hybrid power systems to improve hydrogen fuel economy and make the entire system able to run efficiently overall.

In recent years, various digital cores have been constructed to depict the microstructure of rock. However, how to reveal the evolution of microstructure and fluid flow in the process of mechanical damage is a big challenge. In this paper, based on in-situ uniaxial compression in three-dimensional (3D) X-ray microscopy, the Es3 sandstone was used to study the stress-induced structure deformation and its influence on permeability at pore scale. Both two-dimensional (2D) images and 3D digital cores were reconstructed at different stress stages. During the progressive deformation process of rock, porosity, effective porosity, pore size distribution, pore shape distribution, tortuosity and fractal dimension were obtained. Based on digital cores, the permeability was calculated and seepage path was simulated under different axial stresses. This work revealed that the distribution of pores and effective pores in sandstone is microscopically heterogeneous. In compaction stage, the pores shrank and micro cracks closed, consequently the permeability decreased. In fracturing process, the pores expanded and new cracks were generated, as a result, the permeability significantly increased.

Optical biosensors based on localized surface plasmon resonance (LSPR) have a wide range of applications. They can be used in chemical analysis, such as for quantitative analysis of environmentally hazardous substances. Moreover, the LSPRbased optical biosensing platform is of great significance for the elaboration of optical sensors. Because it is compared with the traditional SPR optical biosensor, on the one hand, the biosensor required by LSPR is faster, more convenient. It can save economic costs to a certain extent. On the other hand, it retains the advantages of traditional SPR biosensors. For example, it is still sensitive to the vibration of the particles, and no complex labeling is required. This paper will focus on applying the LSPR-based optical biosensors in environmental monitoring, biomolecular detection, and the biomedical field. Specifically, the acceptance of the biomedical field not only focuses on the kinds of disease in the body, but also includes the introduction of the accurate detection of the molecular concentration of disease marker.

The biosensing method is a quantitative analysis by comparing color changes, which can be observed by the naked eyes. Therefore, it is widely used in the detection of a variety of targets due to its advantages of simple, low cost, fast, no equipment, and other characteristics. Gold nanoparticles (AuNPs) are typical functionalized nanomaterials and are widely used in developing visual biosensors because of their special optical properties. This paper introduces and reviews the applications of visual biosensors based on AuNPs in the detection of DNA, protein, and heavy metal ions. The advantages compared with traditional detection methods such as fluorescence sensing platforms are pointed out, and the future development of AuNPs-based visual biosensors is prospected.

Under partial shadow conditions, the use of traditional MPPT method will cause multiple peaks on the voltage power curve of the photovoltaic array, reduce the photovoltaic power generation efficiency, and cause a waste of photovoltaic energy. In view of the shortcomings of the traditional photovoltaic MPPT method under partial shadow conditions, this paper uses a power closed-loop control strategy to scan the global maximum power point of the power-voltage curve.Aiming at the disadvantage that the traditional disturbance observation method is easy to fall into unidirectional back-and-forth oscillation, a disturbance observation method with variable step length and anti-misjudgment function is proposed by changing the duty cycle, and the simulation is carried out through SIMULINK to prove the correctness of the method proposed in this paper.

Organic-inorganic hybrid halide perovskites have great potential in solar cells, but they suffer from moisture-induced instability. In this study, we developed a natural material-- tetracosanoic acid (TA) to modify the surface of CH₃NH₃PbI₃ perovskite films to enhance the moisture stability. The power conversion efficiency (PCE) of the TA modified perovskite solar cells (PSCs) retained ~85% of their initial PCE when stored for 20 days at a relative humidity of 25% at 25°C, whereas a pristine cell only retained 54% of its initial value. Our findings demonstrated a simple, inexpensive, and environmentally friendly method to improve moisture stability of PSCs.

This paper study on the aluminum alloy intake tube of an engine which is to be developed and produced by a company. According to the casting process of the component, modern virtual simulation for manufacturing is used to design the product mold, as well as sand core and hot-core box.

Recently, more and more attention are drawn to flexible and wearable electronics due to their potentiality in various industries, including sensing and healthcare. In flexible and wearable electronics fabrications, carbon materials are believed to be an ideal choice because of their outstanding physical and chemical properties like conductivity, flexibility, and stability. This review concentrates on two kinds of carbon materials, carbon nanotubes (CNTs) and graphene, widely studied and implemented in the flexible and wearable electronics industry. CNTs are firstly discussed with their properties and an overview of their synthesis methods. Following this, the manufactural approaches to synthesis CNTs are reviewed from both dry chemistry and wet chemistry perspectives. Then, graphene's potential and synthesis methods are reviewed, with advanced achievements done in recent studies on flexible and wearable devices. In addition, various applications of CNTs and graphene in flexible and wearable electronics are discussed in detail. Finally, the expectation and development directions of desirable materials in the field are discussed.

Aiming at the problem that the distribution position of the gear point cloud is uncertain during the measurement of gear by linear structured light, a mathematical model calculating the theoretical point cloud of involute gear surface is proposed. This model allows us to input gear parameters and measurement parameters to get the corresponding theoretical point cloud. The effectiveness of the proposed method is verified with a set of experiments. The mathematical model is easy to carry out, and it is a good predictor of measurement results. It can be used to study measurement schemes, and simulate measurement results in the absence of experimental equipment.

Based on the study of the design principle of ultrasonic cleaning device, the technology of ultrasonic water treatment and the application of ultrasonic on-line cleaning in membrane bioreactor test, several aspects to be considered in the design of ultrasonic on-line cleaning device in membrane bioreactor are summarized. Through 60-day continuous test, it is shown that the ultrasonic wave with ultrasonic frequency of 40KHz, ultrasonic power of 960W and cleaning time of 5min has a good cleaning effect on Polyvinylidene Fluoride membrane and ultrasonic cleaning has no adverse effect on the growth of microorganisms in Polyvinylidene Fluoride membrane and the quality of the effluent.

With the rapid development of new energy vehicles, people pay more and more attention to the safety problems caused by lithium-ion batteries. If they are not solved, this will inevitably affect the popularization of new energy vehicles in my country. This article introduces the current research progress of thermal runaway of lithium batteries. Firstly, it analyzes the causes of thermal runaway of lithium batteries from the perspective of kinetics, and then focuses on the analysis of the mechanism of battery thermal runaway caused by internal short circuit, external short circuit, overcharge, and overdischarge. In view of the main research progress in these aspects, finally put forward suggestions for the research of lithium batteries.

Transition metal phosphorus-based catalysts have attracted much attention because of their enhanced charge transfer, expanded active surface area and promoted electrolyte migration. The preparation methods of phosphorus bimetal catalysts, the latest research progress in water decomposition devices, supercapacitors and dye-sensitized solar cells are reviewed. Finally, the challenges and future development direction in the field of catalysis are briefly prospected.

In recent years, TiO₂ photocatalytic technology has been effectively applied in the treatment of printing and dyeing wastewater because of its advantages of green, high efficiency and reusability. In this paper, according to the characteristics of difficult treatment of printing and dyeing wastewater and the application defects of TiO₂, the methods of improving the treatment efficiency of printing and dyeing wastewater by TiO₂ modification, doping and co-doping were summarized, in order to provide reference for the application of modified TiO₂ in photo catalytic treatment of printing and dyeing wastewater

As a kind of fluorescent nano material with good optical properties and low toxicity, carbon quantum dots have been developed into a new type of fluorescent probe, which can be used for the detection of heavy metal pollution in the environment. At present, the synthesis methods of carbon quantum dots have been mature, but the research reports on the factors affecting the fluorescence properties of carbon quantum dots are few. This paper, starting from the structure of the carbon quantum dots, focuses on the fluorescence characteristics of the dots, discusses the factors affecting the fluorescence performance of the dots, and compares the methods to improve the fluorescence intensity of the dots. The environmental application of carbon quantum dots is analyzed and prospected.

With the continuous improvement in the requirements for the sound and vibration performance of ships, sound insulation materials should not only be lightweight but also have excellent sound insulation performance. Based on the light weight of the sandwich panel structure and the good low-frequency sound insulation performance of the membrane-type acoustic metamaterial structure, a new membrane-type metamaterial honeycomb sandwich panel structure is designed in this paper. The sound insulation properties of metamaterial structures with different masses are analysed by numerical methods, and the influence of the size of the mass on the sound insulation properties of metamaterial structures is discussed. The sound insulation performance of the circular and mi-shaped mass membrane-honeycomb structures was compared through model experiments, and the sound insulation performance of different core heights and double-layer membrane metamaterial structures was experimentally studied. The experimental results show that the metamaterial structure designed in this paper has excellent low-frequency broadband sound insulation performance.

With the development of science and technology, supercapacitors, as a new efficient and clean energy storage device, have the advantages of environment-friendly, high power density, safety and stability, faster charging and discharging, and excellent cycle stability, etc. To explore the supercapacitor of a higher capacitor capacitance and energy density. This paper introduce an asymmetric supercapacitor where CoS is anode and VN is cathode. This experiment combines characterization methods like SEM, DES, XRD, etc,and the electrochemical detection methods such as CV,GCD to explore the designed supercapacitors.Hope to provide a new idea for the study of supercapacitors.

Two small molecules Y1 and Y2 with diphenylpyranylidene (DPP) as electron-donor and dicyanovinylene or 3- ethylrhodanine as electron-acceptor were designed, synthesized, characterized and applied to organic solar cells as active layer material. Y1 and Y2 showed a wide range of light absorption from 300 to 800 nm in solution and the maximum molar absorption coefficients were up to 30000 to 40000 M^-1cm^-1. Their optical absorption, electrochemical and photovoltaic properties were also studied. The prepared solar cells based on Y1 or Y2 donor and fullerene acceptor achieved PCE of 1.0% and 0.36%, respectively. The crystallization of Y1 and Y2 in blended active layer with fullerene materials as characterized with X-ray diffraction and atomic force microscope technology.

First in this paper, the intelligent automatic lift bottom die in sanitary ceramics manufacturing of social demand, the second analysis extraction process, put forward the overall design scheme of automatic lift bottom die and implementing measures, again to extract the key position and function of the bottom die is analyzed, its structural characteristics, functions and features, its working principle, finally indicated the feasibility and advantage of vertical lathe.

Spinal cord stimulators (SCSs), as a new type of implantable medical device, has been widely studied and applied to alleviate the pain that cannot be alleviated by traditional treatments. Although it is relatively effective in pain relief, the efficacy of this treatment and the safety of SCS remains challenges still. However, due to the limited studies, methodological weaknesses of previous clinical studies, and lack of exploration of the mechanism of pain control in spinal cord injury (SCI), its efficacy, benefit, and mechanism of action in SCI pain remain elusive. Hence, researchers have successfully developed emerging SCSs and improved them in line with the substantial performance testings. In this context, we firstly present the investigations on SCSs in terms of SCS methods, electrode materials, pulse generators, wearable parts, and the mechanisms of power supply. Secondly, a systematic overview of recent advances in SCSs and their impacts on therapeutic efficacy and safety is highlighted. Finally, the clinical manifestations and prospects of SCSs are discussed.

The experimental study was carried out to explore the influence of refrigerant charging amount on the performance of the heat pump system. In the experiment, the amount of refrigerant to be charged was reflected by the pressure during refrigerant charging, and the pressure during refrigerant charging was changed to be 4.5 MPa, 5MPa, 5.5 MPa, 6 MPa and 6.5MPa, the ambient temperature was 25°,C and the outlet water temperature of the heat pump was set to 65°C. Experimental research showed that the refrigerant filling quantity change would affect the CO2 air source heat pump system performance parameters, When the refrigerant charging amount increased, the system had the minimum power consumption and the maximum COP, and the system heat production increased gradually, and the time consuming decreased first and then increased. When the pressure of refrigerant was 6MPa, the CO₂ air source heat pump system reached the best operating condition, with the minimum power consumption of 0.79kW and the maximum COP of 5.11.

This paper uses similar theory to configure a kind of expansive soil to carry out indoor model experiments. By selecting sand, gypsum, and bentonite to artificially configure a mixture with similar expansion and contraction characteristics, the expansion characteristics of expansive soil are studied under water immersion conditions. The experimental results show that the mixture is mainly divided into three changing processes after adding water, the rapid expansion stage, the low-speed expansion stage, and the stable stage. With the changes of bentonite content, gypsum content and sand content, the mixture exhibits different expansion rates, which provides a certain theoretical reference for similar materials in geological model experiments.

In order to obtain the maximum output power of the photovoltaic array under partial shadow conditions, a composite algorithm based on the combination of the cuckoo search algorithm and the conductance increment method is proposed to realize the MPPT tracking control. Early use of SCA's efficient global search function to find the vicinity of the global maximum power point, and then use the fast local tracking capability of INC to find the maximum power point. Through Matlab/Simulink simulation, the obtained results confirm that the algorithm has faster convergence speed and higher search accuracy in photovoltaic multi-peak MPPT, and the oscillation amplitude is smaller.

Metal-organic frameworks (MOFs) are an emerging class of novel adsorbents for natural gas storage and can store natural gas at moderate temperature and pressure with high energy density. To select the suitable MOFs for natural gas storage, the effect of isosteric heat of adsorption, the types of interaction between adsorbents and adsorbates (electrostatic and Van der Waal interaction) and the flexibility of framework of existing MOFs on working capacities are analyzed. It can be found that MOFs with moderate interaction with methane and high density have the greatest working capacities in natural gas storage. Additionally, the flexibility characteristic of some frameworks enables those MOFs to have a high working capacity because there is a dramatic decrease in the amount of gas in pressure change. Furthermore, the factors that affected the practical use of MOFs, namely thermal property, mechanical stability, and impurities in natural gas, are discussed.

Hydrogen, a popular fuel with huge heat of combustion, shows an increasing concern due to its clean light-weighted and clean features, which may have the potential to ease the climate change caused by the greenhouse effect. Metal organic frameworks (MOFs) have been considered as a high-potential material in H₂ storage due to their low cost and the ability to adsorb gases at high speed. In this article, different techniques of hydrogen storage will be discussed. It is founded that MOFs have a latent of H₂ storage, which would replace the traditional methods. Several well-performed MOFs will also be examined: MOF-5 for its high deliverable hydrogen volumetric capacity and reasonable cost, NU-100/PCN-610 for its high excess gravimetric adsorption and the high-pressure swing at 77K, and MOF-210 and HKUST-1 for their high hydrogen capacities with high surface area. The possible factors influencing the performance are BET surface area, pore volume, temperature and pressure and metal-centres. Nevertheless, several limitations caused by the high-standard reaction environment, especially for pressure and temperature, may exist. This paper concludes the general situation of current MOF techniques used in H2 storage and provides reference significance for future research.

The white LED lighting technology has been widely used in daily life, due to the high efficiency, low cost, and remarkable energy conservation. Traditional cold white LED products based on yellow phosphor YAG: Ce³⁺ and blue LED chips is with low color rendering index due to lack of warm red part, and cannot meet the requirements of indoor lighting. Mn⁴⁺ doped fluoride material is one kind of narrow red phosphors emerging in recent years used for both display and lighting. However, the moisture resistance of the Mn⁴⁺ doped fluoride phosphor is poor at present. Herein, we modified the Mn⁴⁺ doped [N(CH₃)₄]₂TiF₆ red phosphor by introducing mixed of external organic ligands to coating the effective luminescent cores, which could significantly improve the fluorescence stability in humidity at room temperature.

Here we report a series of molecular dynamics simulations to explore the hydrogen bonds (HBs) behavior of ethylammonium nitrate (EAN) protic ionic liquid(IL)-water mixtures with different concentrations at the interface with POPC bilayers. Our simulation results clearly demonstrate that the POPC–H₂O and POPC–EA⁺ HBs are strongest among all kinds of HBs, so that all of the EA⁺–NO^-₃, EA⁺–H₂O, NO₃––H₂O, and H₂O–H₂O HBs at the interface are enhanced compared to those in the bulk phase. Specifically, the order of these HB strength at the interface is POPC–H₂O > POPC– EA⁺ > H₂O–H₂O < NO^-₃ –H₂O < EA⁺–H₂O > EA⁺–NO^-₃ HBs. Furthermore, increasing EAN concentration can be favorable to a further enhancement of all these HB strength at the interface, which lead to slower rotations of EA⁺, NO^-₃, and H₂O as the EAN concentration increases. Accordingly, the relevant HB networks around the EA⁺, NO^-₃ and H₂O are also found to change considerably with the addition of EAN protic ionic liquid. Our simulation results in this work provide some molecular-level insights into the concentration-dependent HB behavior of protic ionic liquid-water mixtures at the interface of phospholipid bilayer, which is of great importance for scientist to understand the influence of ionic liquid on the function of cell membranes.

Reinforced concrete is widely used in our engineering buildings. Reinforced concrete is the use of concrete pressure resistance and reinforced pull performance, the integration of the two can be very good to improve the ability to resist external forces. However, rebar is prone to rust, after corrosion, the performance of rebar will be greatly reduced, which will affect the overall force of reinforced concrete. Therefore, it is of great significance to study the mechanics of steel bars after corrosion. In this experiment, the rapid corrosion of steel bars of 12mm and 16 mm diameters was carried out by electrochemistry rapid corrosion, and the anti-pull performance test was carried out, and 12 were established by experimental data Stress-strain relationship images of two diameter rusted rebars with different corrosion rates, which are fitted with experimental data to analyze the law of changes in the dynamic properties after corrosion. The fitting equation of the characteristics of the characteristics of the mechanics such as yield strength, yield strain, limit strength and limit strain of rusted rebar is obtained. By fitting the equation, it can be concluded that with the increase of corrosion rate, the yield strength and limit strength of rebar are constantly decreasing, but yield strain and limit should become irregular changes.

Rubber concrete has a promising application due to its good ductility. However, how to solve the reduction of its strength is a key issue. In view of the inadequate mechanical properties of rubber concrete at present, this paper carried out a study of blending hybrid fibers (steel fiber-basalt fiber) into rubber concrete to improve the mechanical properties of the concrete. The effect of rubber powder, steel fiber and basalt fiber on the compressive strength and the flexural strength of concrete at different admixtures was studied experimentally using the method of orthogonal test design. The results show that the incorporation of rubber powder would reduce the compressive strength and flexural strength of concrete to some extent, but the reasonable incorporation of hybrid fiber could compensate for the loss of strength caused by rubber powder instead of fine aggregates. In this test, the maximum increase of compressive strength and flexural strength of the hybrid fiber rubber concrete(HFRC) after further incorporating with mixed fibers were 12.75% and 30.89%, respectively. Steel fiber(SF) is an important factor affecting the flexural strength of HFRC, and the improvement of the compressive strength by basalt fiber(BF) is not significant. The improvement of the flexural strength of HFRC by hybrid fiber was greater than that of the compressive strength. The combination of hybrid fiber and rubber concrete with optimal mechanical properties is obtained by extreme difference analysis, which provides a certain theoretical basis for the engineering application of blended fiber and rubber concrete.

Compared with the traditional reinforced concrete and masonry culvert engineering, the corrugated steel pipe culvert structure has excellent construction and use performance. There are many mechanical calculation methods for corrugated steel pipe culverts, but there are certain limitations due to different degrees of simplification of the calculation model. Aiming at the stress and deformation characteristics of flexible high-filled corrugated steel pipe culverts under the action of soil filling, this paper selects the trough section in the middle of the culvert axis, the trough section in the middle of the culvert axis, the trough section at the entrance of the culvert, and the culvert through filling and static load tests. The four corrugated steel corrugated pipe culvert sections at the wave crest section of the cave entrance are equipped with strain gauges, earth pressure cells and deformation measuring instruments to study the stress, strain, and displacement mechanical characteristics of the corrugated steel pipe culvert, and obtain the mechanical deformation characteristics of the corrugated steel pipe culvert under static load. The law of deformation. The research results show that: 1) Under the load of the same fill height, the vertical stress of the corrugated steel pipe culvert is smaller than the vertical stress of the soil without a culvert. The pressure is greater than the stress in the soil at the same height; 2) Due to the different directions of the surrounding earth pressure on the pipe culvert during the filling process, tension and compression changes occur at multiple locations, and the strain at the top and waist of the pipe culvert is often larger, so this point is a weak point relative to other measuring points.

Cotton fabrics is a kind of widely used but easily ignited textile fibers. In order to improve its flame retardant, an eco-friendly and simple method is proposed. Different amounts of coatings containing phosphoguanidine (PHO), ATMP and alginate (AL) were assembled on cotton fabric surface by layer-by-layer (LbL) technique. FTIR spectra indicated that the LbL coating was successfully deposited on the surface of cotton fabric. Char residue of TGA over 20wt% indicated the performance of the thermal stability for all treated samples had significantly increased. From the MCC test, the peak heat release rate (PHRR) showed a obviously decrease of over 50% and and the achievement of the coated samples in a self-extinguished level from vertical combustion test. All these results demonstrated that the PHO/ATMP /AL-coated cotton fabrics had excellent flame retardancy and revealed the importance of PHO/ATMP /AL coating in enhancing the flame retardancy for cotton fabrics.

Radio frequency ablation instrument is a kind of surgical equipment widely used in medical institutions, and output power is one of the most important technical parameters of this instrument. However, until now, there is no corresponding verification regulation or calibration specification for the validation of metrological traceability and performance reliability of such instruments. By analyzing the measurement principle of quality analyzer for electrosurgical generator and the output power range of radio frequency ablation instrument, this article presents a solution, which is to test the output power of radio frequency ablation instrument according to JJF 1217-2009 Calibration Specification for Electrosurgical Generator, and the feasibility of the design is evaluated as well bycomparing the test results with the data acquired by following measurement procedure recommended by industry standards to confirm the feasibility of the novel design.

The development of photovoltaic power generation is on the rise, but there are some problems to be solved, the existing model is difficult to solve distributed photovoltaic brings a series of questions, therefore, this article introduced block point technology, in the decentralized, smart and consensus contract mechanism and so on were analysed, and the description block chain technology to solve the problem of distributed photovoltaic efficiency. Through analysis, it can be found that blockchain technology can solve some thorny problems.

Photovoltaic energy has been widely studied and applied in the power grid in recent years due to its sufficient cleanliness and resource adequacy. However, the increase in photovoltaic penetration rate will also threaten the safe operation of the system. This paper establishes a photovoltaic system model and a microgrid model based on DIgSILENT to quantitatively study the photovoltaic system characteristic curve considering the influence of environmental parameters, and conducts research and analysis before and after the photovoltaic system is connected to the grid and participates in frequency modulation. The simulation results show that the photovoltaic system model and frequency regulation strategy established in this paper have practical value.

Oxide Vertical Cavity Surface Emitting Lasers(VCSELs) are widely used in high-speed optical communication applications. An important specification for VCSELs is field reliability. However, oxide VCSELs are vulnerable to dislocation defect due to the inherent reasons of materials system and structural design. In order to better understand the failure modes and causes of oxide VCSELs, improve the reliability of the chip and reduce the failure rate, we summarize and analyze the most common failure modes, causes observed in oxide VCSELs from five aspects of materials system, structure design, manufactu

The same batch of green LEDs were subjected to thermal stress aging for different periods of time. The I-V characteristic test result shows that the current of the aging device under the same bias voltage increases, and the increase is positively correlated with the aging time. Observing the light-emitting condition of the device under the CCD lens, it is found that the long-term aging leads to the deterioration of the light-emitting characteristics of the device. The current transport mechanism is analyzed based on the test results of I-V characteristics and optical characteristics. Finally, the influence of the trap on the luminous characteristics of the green LED was verified by the Silvaco TCAD simulation tool.

The stability of the infrared focal plane array (FPA) is the key to long-term quantitative testing. Due to the influence of external factors, such as thermal shock, vibration, temperature drift, etc., the response of the infrared array detector will change to a certain extent. The drift of the response will cause the generation of new blind pixel and the change of response non-uniformity, which will seriously affect the image quality, and the traditional long-term stability measurement method is inefficient. In response to the above problems, we propose a novel protocol and method to automatically characterize the temporal stability of infrared detector, which can automatically generate performance parameters such as infrared detector response rate and non-uniformity to evaluate the stability. The research provides valuable experience for the longterm analysis of HgCdTe infrared focal plane array.

Fringe projection technique has been widely used in numerous areas including manufacturing, medical science, computer science, entertainment, and documentation of cultural artifacts. However, there are problems when measuring a complex scene with a large range of reflectivity variations, where minimum human intervention is usually desirable. This paper presents a framework that can determine the optimal number of projected light intensities and corresponding intensity values for high-quality three-dimensional (3D) shape measurement with digital fringe projection technique. By using the k-means clustering algorithm, we can calculate the distribution of surface reflectivity and thus predict the optimal number of projected light intensities and corresponding intensity values. Experimental results demonstrate that the proposed framework can be successfully applied to the measurement of complex scenes whose histogram does not show apparent peaks and troughs.

The uniformity of carbon line will seriously affect the combustion appearance of cigarettes in terms of intuitive feeling, which may cause fluctuations in sensory quality and improvement of the falling tendency of combustion cone. In this paper, the uniformity of carbon wire is determined, the calculation method of two parameters is studied, and the full vision test equipment is used to test. The test results show that the uniformity of cigarette carbon thread with the same crack rate is different, which can be used to measure the appearance quality of cigarette during combustion. The average carbon line width of fine cigarettes, medium cigarettes and thick cigarettes was 1.39, 0.84 and 1.96 respectively. The equipment for measuring cigarette combustion appearance quality with full vision adopts the way of three-side photography in the process of measuring indicators, and the difference rate of test results of three-side photography of the same cigarette is large.

According to the contents of the latest edition of the standard, the paper provides a fast and efficient washing test device which can fully meet the pollution resistance of ceramic tiles. The realization of the ceramic tile pollution resistance test device will make the test cleaning procedures to be quantified, and easy to operate, simple, shorten the test time, improve the test efficiency, with fast experimental results, high accuracy, small error, high efficiency and a wide range of application. The experiment time is shortened but the experiment result is accurate and efficiency is greatly improved.

In this review, the mechanism of LED light emission and the formation of barrier height on GaN-based semiconductor are analyzed, which affects the device electrical properties. After explanation of Ohmic contact physics, to achieve Ohmic contact to p-type GaN is considered as the rather difficult work. The method to improve the conductivity of contact to pGaN is concluded. The surface treatment is suggested to remove insulating native oxide on GaN surface while the annealing in oxygen ambient may have multiple effects on p-GaN structure or active carrier concentration, although the mechanism of annealing is still a controversial issue. Ni with Au cap layer is a popular scheme for p-GaN but the property could be further improved via the formation of solid solution with other divalent metal or those extracting hydrogen. Finally, the use of superlattice/strained layer like AlGaN or InGaN could create 2-D hole gas, which further boosts the carrier concentration.

Ash line width affects consumers' judgment of cigarette quality. In this paper, the width of ash line is determined and its calculation method is studied, which is tested by full vision testing equipment. The test results show that the width of ash line of cigarettes with the same crack rate is different, which can be used as an index to measure the appearance quality of cigarettes in the process of combustion. The average ash line width of the measured sample is larger for common cigarettes than for medium and slim cigarettes. In the process of moving backward with the combustion section, the carbonization line is affected by factors such as cut tobacco structure, filling density, cigarette paper and leaf group formula. The equipment for measuring cigarette combustion appearance quality with full vision adopts the method of three-side photography in the process of measuring indicators, and the test results of three-side photography of the same cigarette have a large difference rate, which is better than single-side photography.

In this work we report a detailed analysis of the current & charge density-voltage variance from tris(8-hydroxyquinoline) aluminum based organic light emitting diodes using general-purpose photovoltaic device model (GPVDM) software as a function of the thickness of CdS as the buffer layer. The electrical and optical parameters of all layers were extracted from the material directory available in GPVDM. The calculations fully consider dispersion in glass substrate, indium tin oxide anode, the organic layers as well as the dispersion in the metal cathode. As expected, applied voltage was strongly dependent on the thickness of the buffer layer inside the devices. Finally, guidelines for designing devices with optimum turn-on voltage and thickness are presented.

With the continuous development of social informatization, thermal label and barcode printing technology has gradually spread across all walks of life. It is also important to improve the recognizability of thermal printing barcodes. Improving printing clarity at high speeds has become a key point in the design of thermal printers. With the increase of the printing speed in the traditional heating control method, the time for the temperature rise and fall of the heating element of the print hair will not be negligible, which will not neglect the impact of the printing clarity, which will result in the reduction of the printing clarity. However, it is difficult and costly to start from the perspective of structure, material, etc., to improve printing clarity. Combined with the printer history and future heating point information, this paper applies different heating pulse width compensation to the heating element while increasing the number of heating pulses and reducing the heating pulse width. Through the finite element simulation and the comparison with the actual printing effect of the thermal printer, the effectiveness of the method is verified. The results show that the control method can effectively improve the printing clarity and the recognition rate of barcodes and QR codes.

Photovoltaic power generation system is very dependent on the sun's irradiation, any change in the external environment will affect the performance of photovoltaic power generation system. The partial shadow on the photovoltaic array will also affect the power output, and also increase the complexity of maximum power point tracking. In the case of partial shading, the power-voltage characteristic curve of the photovoltaic array has multiple local maximum power points, in order to track the global maximum power point quickly and accurately, a control method based on the combination of cuckoo search algorithm and conductance increment method is proposed, the cuckoo search algorithm is used in the early stage of tracking, and the conductance increment method is switched to tracking when it reaches the maximum power point. Through the simulation analysis of the model built by MATLAB/Simulink, it can be found that the algorithm has a faster tracking speed compared with the traditional cuckoo search algorithm, and also has a good steady-state accuracy.

In this paper, using ferric chloride as catalyst, the graphitization of anthracite and petroleum coke was studied. The results show that the optimum dosage of ferric chloride is 10% for the graphitization of anthracite and 7.5% for the graphitization of petroleum coke. The effect of roasting temperature on the graphitization of anthracite and petroleum coke catalyzed by ferric chloride is remarkable, and the best temperature is 1400°C in experimental temperatures. The effect of roasting holding time on the graphitization of anthracite and petroleum coke catalyzed by ferric chloride is positive, and the effect is not obvious after 120min. Under the optimal experimental conditions, the highest graphitization degree of anthracite and petroleum coke catalyzed by ferric chloride are 37.21% and 31.97%, respectively. It intimates that the catalytic effect of ferric chloride on anthracite is better than that on petroleum coke.

Based on the biological environment floristic representative five phyla nine families 9 kinds of biological species as the research object, the acute / chronic biotoxicological tests of alkylbenzene sulfonate surfactants were carried out under the water environment conditions of an oil field experimental mining area. The biological benchmark threshold range of alkylbenzene sulfonate surfactants in the water environment of the mining area was constructed.

Vinyl acetate is a bulk chemical consumed by millions of tons annually. It has a wide range of uses and broad development prospects, but also means that there is a large space for improvement in the application of advanced technology. Acetylene gas phase method commonly used at present has the advantages of high selectivity and low equipment requirements, but the process has high energy consumption, so it is necessary to optimize the energy saving aspect of the process. In this design, Aspen Plus is used to simulate and analyze the existing process, pinch point technology is used to optimize the heat exchange network, and heat pump distillation and double-effect distillation technology is used to optimize the reaction and separation equipment to reduce energy consumption and achieve the goal of energy saving. The simulation results show that the energy recovery of the improved process is 0.49×105kW, namely 49.81mW, and the energy recovery is 28.6%. At the same time, in the process of producing vinyl acetate in this project, the recycling and utilization of byproducts can achieve a circular economy and meet the requirements of green development 2020 in “Made in China 2025”.

Isopropanol is an extremely widely used chemical product. With the outbreak of COVID-19 worldwide, the export demand of isopropanol keeps increasing, and the supply is in short supply. In order to meet the demand of isopropyl alcohol in the international market, the existing production process faces new challenges and needs to be improved and upgraded. In this design, Aspen Plus was used to simulate the existing hydrogenation process of acetone to isopropanol, and it was improved and optimized to establish an annual output of 5 kT isopropanol and a variety of by-products of different specifications. The process adopts double-effect distillation and heat pump distillation to reduce energy consumption, and a set of waste liquid recovery device is designed to effectively recover the by-products and achieve the purpose of improving economic benefits. Simulation results of Aspen Plus show that energy consumption, carbon emission, water consumption and solid waste utilization rate can be reduced by 36.73%, 40%, 45% and 80% respectively, meeting the requirements of “Made in China 2025”.

As the quality of crude oil deteriorates and environmental regulations become increasingly stringent, the production of clean oil with ultra-low sulfur content is becoming increasingly urgent. At present, HDS is the most extensive technology for producing clean fuel oil. In this paper, MoS₄²- solution was successfully synthesized and used as precursor to prepare new sulfided NiMo/Al₂O₃ hydrodesulfurization (HDS) catalysts. The catalyst was characterized by x-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HRTEM) and assessed using the typical refractory 4,6-dimethyldibenzothiophene (4,6-DMDBT) as the model reactant. Results show that, compared with the conventional oxidized catalysts, the sulfided catalyst not only exhibits much higher sulfidation degree of Mo species, but also holds shorter and more suitable MoS₂ stacks, resulting in better HDS activity.

The acceleration of industrialization in the world has made the topic of environmental protection more and more prominent, and the situation of environmental protection in the world has become more urgent in the 21st century. With the increasing awareness of environmental protection and environmental-friendly concepts, plant dyes have been widely used in modern handmade textiles, and the extraction and application of plant dyes has become a hot research topic. This paper elaborates the research progress of a violet dye extraction method and dyeing application technology from the three aspects: the characteristics of violet plant dye on safety and environmental protection, the extraction method of plant dye science, and the practice of protein fiber dyeing. This paper also clarifies the research direction of plant dye extraction and protein fiber dyeing technology, and projects the development potential of environmental-friendly natural plant dye, with a purpose to provide reference for the development and utilization of plant dye.

Spinel oxides of special crystal structure and composition, have been widely applied in biotechnology, laser, sensor technologies, and conversion reaction. In this work, FeCo₂O₄ powders were prepared by hydrothermal, solid-state, and sol-gel methods to explore the optimal synthesis process of spinel oxides. The effects of annealing temperature on spinel structure were also investigated. In addition, the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) electrocatalytic activities, and practical applications of FeCo₂O₄ in electrochemical energy conversion devices were explored. Specifically, single-phase FeCo₂O₄ with smaller particle sizes can be prepared by a procedure including the hydrothermal method and subsequent annealing at 900°C. Moreover, the composite of FeCo₂O₄ and EC600JD shows splendid OER and ORR activities. And FeCo₂O₄ spinel oxide reaches a maximum power density of 97.63 mWꞏcm^-2 when applied as air cathode of the aluminum-air battery. Our work demonstrates that FeCo₂O₄ with a simple synthesis process and preeminent electrocatalytic performance is a promising catalyst for metal-air batteries.

π-conjugated polymers (PCPs) are suitable gain materials for laser applications due to their high photoluminescence (PL) quantum yield. However, the effect of molecular weight on amplified spontaneous emission (ASE) of PCPs is unknown. In this work, we investigated ASE in poly [2-methoxy-5-(2'ethylhexyloxy)-1, 4-phenylethylene] (MEH-PPV) with different molecular weight in 0.5 mg/mL, 1 mg/mL and 2 mg/mL solutions by using a pulsed laser with pulse width of 10 ns. The molecular weights are 40000-70000, 70000-100000, and 100000-150000, respectively. We found that the threshold decreases as the molecular weight increases, which is due to higher emission intensity at larger molecular weight. In addition, the threshold decreases with concentration increasing, this is because slightly aggregation is helpful for ASE. Our results have shown that molecular weight as well as concentration play an important role in the ASE threshold in MEH-PPV solutions, as well as PCP lasers.

On the basis of previous studies, this paper studies the common close joints between composite slabs and proposes a method of dense connection of carbon fiber composite strips at the bottom of the slab. Based on the static load comparative test of six rectangular single slit two-way composite slabs with simply supported and seamless connection on four sides, the bending performance, bearing characteristics and deformation capacity of carbon fiber reinforced concrete and seamless connection two-way composite slabs are studied from three aspects of stress characteristics, failure mode and stress state. The results show that the simply supported composite floor with a seamless connection can achieve two-way force transmission, and there is no crack concentration at the joints. This paper summarizes the relevant experience of inspection, identification, design, construction, and use in the reinforcement and reconstruction of mixed structures. For reference to similar projects in the future.

With the lack of manpower, the development of intelligent automation and the promotion of the concept of green environmental protection, 3D printed concrete technology has become a hot spot in the construction industry. Different from the traditional concrete construction technology, 3D printed concrete components can be printed and manufactured in-situ at the construction site. In order to explore the application possibility of 3D printing technology in in-situ printed components, this paper studies the axial compressive performance of in-situ printed core column reinforced concrete wall. The main research contents are as follows: In this paper, 12 pieces of in-situ printed core-column reinforced concrete walls are designed and produced, and the basic form of in-situ printed core column reinforced concrete walls is elaborated. Influencing factors such as the number of core columns, the stirrup configuration forms of core columns, reinforcement ratio and connection modes of transverse reinforcement are set. Axial compression performance experiment was carried out on the wall specimens to study the failure modes and mechanical performance of the in-situ printed core column wall under the action of axial load.

It is of great significance to develop wall materials with good thermal and mechanical properties for the wall self-insulation system. In the present paper, a new type of self-insulating concrete has been developed using waste rock wool, vitrified micro beads, cement, mineral powder, sand and gravel as raw materials. The effects of related parameters on concrete strength, thermal conductivity and dry bulk density have been analyzed by orthogonal experiments. The test results show that the content of cementing material and the content of vitrified micro beads are the most important factors affecting the thermal conductivity, compressive strength and dry bulk density of self-insulating concrete; the content of rock wool has a significant effect on the thermal conductivity while has little effect on the compressive strength and dry bulk density; the water-binder ratio has a certain effect on the compressive strength and dry bulk density while has little effect on the thermal conductivity. In the case of the best mix ratio, the average thermal conductivity of self-insulating concrete is 0.195 W/(mꞏK), the average compressive strength is 15.31 MPa, the average dry bulk density is 1637 kg/m³, and the average moisture content is 5.7%. All the above indicators meet the expected performance requirements of self-insulating concrete.