This study begins with the fabrication and simulation of high-performance back-illuminated AlGaN-based solar-blind ultraviolet(UV)photodetectors.Based on the photodetectors,a low-noise,high-gain UV detection system ci...This study begins with the fabrication and simulation of high-performance back-illuminated AlGaN-based solar-blind ultraviolet(UV)photodetectors.Based on the photodetectors,a low-noise,high-gain UV detection system circuit is designed and fabricated,enabling the detection,acquisition,and calibration of weak solar-blind UV signals.Experimental results demonstrate that under zero bias conditions,with a UV light power density of 3.45μW/cm^(2) at 260 nm,the sample achieves a peak responsivity(R)of 0.085 A·W^(−1),an external quantum efficiency(EQE)of 40.7%,and a detectivity(D^(*))of 7.46×10^(12) cm·Hz^(1/2)·W^(−1).The system exhibits a bandpass characteristic within the 240–280 nm wavelength range,coupled with a high signal-to-noise ratio(SNR)of 39.74 dB.展开更多
MnCO_(3)represents a potentially high-capacity and low-cost anode candidate to replace graphite for enhancing energy density of commercial lithium-ion batteries,but it suffers from poor electrical conductivity and ser...MnCO_(3)represents a potentially high-capacity and low-cost anode candidate to replace graphite for enhancing energy density of commercial lithium-ion batteries,but it suffers from poor electrical conductivity and serious volumetric change,largely hindering its practical applications.展开更多
ZFJ Textile Machinery Co.,Ltd.,established in 1949,is a key enterprise directly managed by China Hi-Tech Group Corporation and falls under the jurisdiction of China National Machinery Industry Corporation Limited(Sino...ZFJ Textile Machinery Co.,Ltd.,established in 1949,is a key enterprise directly managed by China Hi-Tech Group Corporation and falls under the jurisdiction of China National Machinery Industry Corporation Limited(Sinomach).As a leading enterprise in the textile machinery manufacturing industry,ZFJ is dedicated to providing global customers with complete equipment solutions covering the entire industry chain.During this exhibition,ZFJ primarily highlights three key features:"high-performance fibers,green fibers,and intelligent equipment,"with a focus on showcasing nine types of products,spanning various textile equipment categories,including chemical fiber,specialty fiber,nonwoven,sizing,and dyeing machinery.展开更多
Lithium/fluorinated carbon(Li/CF_(x))batteries are greatly limited in their applications mostly due to poor rate performances.In this study,N,P co-doped biomass carbon was synthesized using melamine and phytic acid as...Lithium/fluorinated carbon(Li/CF_(x))batteries are greatly limited in their applications mostly due to poor rate performances.In this study,N,P co-doped biomass carbon was synthesized using melamine and phytic acid as doping sources,and the resulting product was then utilized as a precursor for CF_(x).The resulting fluorinated biomass carbon has a high degree of fluorination,exceeding the specific capacity of commercial fluorinated graphite while also demonstrating exceptional performance at high discharge rates.During the fluorination process,N,P-containing functional groups were removed from the crystalline lattice in the basal plane.This facilitates the formation of a defect-rich carbon matrix,enhancing the F/C ratio by improving the fluorinated active sites and obtaining more highly active semi-ionic bonds.Additionally,the abundant defects and porous structure promote Li^(+)diffusion.Density functional theory calculations indicated that doping modification effectively reduces the energy barrier for Li+migration,enhancing Li+transport efficiency.The prepared CF_(x)delivers material with a maximum specific capacity of 919 mAh·g^(-1),while maintaining a specific capacity of 702 mAh·g^(-1)at a high discharge current density of 20C(with a capacity retention rate of 76.4%).In this study,fluorinated N,P co-doped biomass carbon,exhibiting ultrahigh capacity and high-rate performance,was prepared for the first time,which can potentially advance the commercialization of CF_(x).展开更多
A high-performance liquid chromatography(HPLC)method has been developed using a CAPCELL PAK ADME(150 mm×4.6 mm,5μm)as analytical column and a gradient elution with 15 min using acetonitrile and 0.1%(in volume fr...A high-performance liquid chromatography(HPLC)method has been developed using a CAPCELL PAK ADME(150 mm×4.6 mm,5μm)as analytical column and a gradient elution with 15 min using acetonitrile and 0.1%(in volume fraction)phosphoric acid water(pH=2.2)as the mobile phase.Three active substances in cosmetics were quantitatively detected simultaneously at a detection wavelength of 265 nm.The linear ranges of β-nicotinamide mononucleotides,ergothioneine and nicotinamide are 10~200 mg/L,5~100 mg/L and 5~100 mg/L respectively and the detection limits of three components are 3.0 mg/L,1.5 mg/L and 1.5 mg/L respectively.The recovery rate is 97.1~104.9%,with RSD≤2.0%.The method was applied to quantitative analysis of five samples of cosmetics toner,lotion,cream,essence and gel and three samples of raw materials.The results showed that the results of β-nicotinamide mononucleotide and ergothioneine in five cosmetics were consistent with the product label,while nicotinamide was inconsistent with the label.The purity of the three raw material samples was 99.5%,99.7% and 100.8%respectively.This method offers high precision,accuracy and short analysis time,making it a reliable approach for studying three active ingredients in cosmetics and suitable for quality control of related functional ingredients.展开更多
Anode active materials involving transition metal oxides and sulfides are of great significance for high energy density lithium-ion batteries(LIBs),but the huge volume expansion and inferior electronic conductivity up...Anode active materials involving transition metal oxides and sulfides are of great significance for high energy density lithium-ion batteries(LIBs),but the huge volume expansion and inferior electronic conductivity upon cycling critically constrain their further application.Herein,from a new perspective,a highly conductive and stable 3D flexible composite current collector is rationally designed by facilely electrodepositing metallic Ni thin layer onto the carbon cloth(CC/Ni),which endows the supported active materials with exceptional electronic conductivity and structural stability.In addition,the homogeneously distributed metallic Ni protrusions external CC can strongly bond with the active components,ensuring the structural integrity of electrodes upon cycling.More importantly,the 3D network structure with large specific surface area provides abundant space to alleviate the volume expansion and more active sites for electrochemical reactions.Therefore,taking Ni_(3)S_(2)nanosheet(Ni_(3)S_(2)NS)anode as an example,the prepared Ni_(3)S_(2)NS@CC/Ni electrode shows a high specific capacity of 2.32 mAh/cm^(2)at 1mA/cm^(2)and high capacity retention of 1.68 mAh/cm^(2)at a high rate of 8mA/cm^(2).This study provides a universal approach to obtain highly conductive and stable 3D flexible current collectors towards high performance metal-ion batteries beyond LIBs.展开更多
The weak interlayer van der Waals(vdW) interactions in two-dimensional(2D) vdW materials enable sliding ferroelectricity as an effective strategy for modulating their intrinsic properties. In this work, we systematica...The weak interlayer van der Waals(vdW) interactions in two-dimensional(2D) vdW materials enable sliding ferroelectricity as an effective strategy for modulating their intrinsic properties. In this work, we systematically investigate the influence of interlayer sliding on the electronic behavior of PtSe_(2) using density functional theory(DFT) calculations. Our results demonstrate that interlayer sliding induces a pronounced photocurrent spanning the short-wavelength infrared to visible spectral ranges. Remarkably, under an applied gate voltage, the sliding ferroelectric PtSe_(2) exhibits anomalously enhanced photovoltaic performance and an ultrahigh extinction ratio.Transmission spectral analysis reveals that this phenomenon originates from band structure modifications driven by energy-level transitions. Furthermore, the observed photocurrent enhancement via sliding ferroelectricity demonstrates universality across diverse platinum-based optoelectronic devices. This study introduces a novel paradigm for tailoring the intrinsic characteristics of 2D vdW semiconductors, expanding the design space for next-generation ferroelectric materials in advanced optoelectronic applications.展开更多
With the most advanced and sophisticated technologies and equipment,NYBELT is one of the largest manufacturers of flat transmission belts in the world.Under the Certified Quality,Environment,Occupational Health&Sa...With the most advanced and sophisticated technologies and equipment,NYBELT is one of the largest manufacturers of flat transmission belts in the world.Under the Certified Quality,Environment,Occupational Health&Safety,and Energy Standardized ISO Management System,NYBELT can produce all kinds of flat transmission belts,roller coverings and conveyor belts applicable to textile,printing&packaging,electronics and other industries.Due to the superior quality and the reasonable prices,we have become well known in providing high quality belting products and excellent service to customers all over the world.Our success in the past gives us the confidence to look into the future with great expectations.展开更多
Maintaining stable high temperatures under pressure remains a challenge in high-pressure,high-temperature experiments using multi-anvil presses(MAPs).Temperature fluctuations exceeding 10℃ at high pressures are commo...Maintaining stable high temperatures under pressure remains a challenge in high-pressure,high-temperature experiments using multi-anvil presses(MAPs).Temperature fluctuations exceeding 10℃ at high pressures are common and particularly problematic with LaCrO_(3) heaters,which can experience significant power fluctuations and even failure due to substantial resistance changes—an issue conventional thyristorcontrolled heating systems cannot effectively manage.To address this limitation,we have developed the Multi-Anvil Stable Temperature controller(MASTer),a high-performance heating system optimized for MAP experiments.MASTer enables precise,high-speed measurement of heating parameters and power output control,incorporating a gentle regulation strategy to enhance stability.It ensures consistent heating across various heater types,including LaCrO_(3),with power fluctuations limited to±0.1 W and temperature fluctuations to within±2℃ in most cases.The design,operating principles,user interface,functionality,and performance of the heating system are discussed in detail.展开更多
This study aims to assess the comprehensive strengthening effect of a steel-ultra high performance concrete(UHPC)composite strengthening method.The axial force-moment interaction curve(N-M curve)was calculated in a no...This study aims to assess the comprehensive strengthening effect of a steel-ultra high performance concrete(UHPC)composite strengthening method.The axial force-moment interaction curve(N-M curve)was calculated in a novel way,using cross-sectional strains at ultimate states as well as real-time stress measurements for each material.The enclosed area of the N-M curve was defined as a comprehensive performance index for the system.We validate our approach with comparisons to numerical modeling and full-scale four-point bending experiments.Additionally,strengthening effects were compared for different sagging and hogging moments based on material stress responses,and the impact of various strengthening parameters was analyzed.We find that the N-M curve of the strengthened cross-section envelops that of the un-strengthened cross-section.Notably,improvements in flexural capacity are greater under sagging moments during the large eccentric failure stage,and greater under hogging moments during the small eccentric failure stage.This discrepancy is attributed to the strength utilization of strengthening materials.These findings provide a reference for understanding the strengthening effects and parameters of steel-UHPC composite.展开更多
Significant contributions have been made to understanding the processing of various metal materials using laser powder bed fusion (LPBF) for the design and fabrication of high-performance metal components in many fiel...Significant contributions have been made to understanding the processing of various metal materials using laser powder bed fusion (LPBF) for the design and fabrication of high-performance metal components in many fields. For laser additive manufacturing, aluminum-based materials are regarded as difficult-to-fabricate materials be- cause of their special physical properties, including low density, low laser absorption, high thermal conductivity, and ease of oxidation. Currently, LPBF-formed structural materials require high densification, fine grains, high specific strength, high ductility, and optimized physical or chemical properties. Therefore, comprehensive un- derstanding of the fabrication and performance of Al-based materials processed by LPBF is of significant value. This paper covers emerging research on aluminum-based materials using LPBF, providing an overall view of the basic scientific mechanisms behind manufacturing. The state-of-the-art researches of aluminum-based materials for LPBF formability as well as the microstructures, properties and corresponding metallurgical mechanisms are reviewed. The mechanisms of some of the main defects (pores, cracks, balling, and oxide inclusions) and control measures are also discussed. A summary and outlook for the further development of Al-based materials for LPBF are addressed.展开更多
All-inorganic CsPbIBr_(2) perovskite has attracted widespread attention in photovoltaic and other optoelectronic devices because of its superior thermal stability.However,the deposition of high-quality solutionprocess...All-inorganic CsPbIBr_(2) perovskite has attracted widespread attention in photovoltaic and other optoelectronic devices because of its superior thermal stability.However,the deposition of high-quality solutionprocessed CsPbIBr_(2) perovskite films with large thicknesses remains challenging.Here,we develop a triple-component precursor(TCP) by employing lead bromide,lead iodide,and cesium bromide,to replace the most commonly used double-component precursor(DCP) consisting of lead bromide and cesium iodide.Remarkably,the TCP system significantly increases the solution concentration to 1.3 M,leading to a larger film thickness(~390 nm) and enhanced light absorption.The resultant CsPbIBr_(2) films were evaluated in planar n-i-p structured solar cells,which exhibit a considerably higher optimal photocurrent density of 11.50 mA cm^(-2) in comparison to that of DCP-based devices(10.69 mA cm^(-2)).By adopting an organic surface passivator,the maximum device efficiency using TCP is further boosted to a record efficiency of 12.8% for CsPbIBr_(2) perovskite solar cells.展开更多
Flexible electrode design with robust structure and good performance is one of the priorities for flexible batteries to power emerging wearable electronics,and organic cathode materials have become contenders for flex...Flexible electrode design with robust structure and good performance is one of the priorities for flexible batteries to power emerging wearable electronics,and organic cathode materials have become contenders for flexible self-supporting electrodes.However,issues such as easy electrolyte solubility and low intrinsic conductivity contribute to high polarization and rapid capacity decay.Herein,we have designed a flexible self-supporting cathode based on perylene-3,4,9,10-tetracarboxylic dianhydride(PTCDA),interfacial engineering enhanced by polypyrrole(PPy),and carbon nanotubes(CNTs),forming the interconnected and flexible PTCDA/PPy/CNTs using polymerization reaction and vacuum filtration methods,effectively curbing those challenges.When used as the cathode of sodium-ion batteries,PTCDA/PPy/CNTs exhibit excellent rate capability(105.7 mAh g^(−1) at 20 C),outstanding cycling stability(79.4%capacity retention at 5 C after 500 cycles),and remarkable wide temperature application capability(86.5 mAh g^(−1) at−30℃ and 115.4 mAh g^(−1) at 60℃).The sodium storage mechanism was verified to be a reversible oxidation reaction between two Na+ions and carbonyl groups by density functional theory calculations,in situ infrared Fourier transform infrared spectroscopy,and in situ Raman spectroscopy.Surprisingly,the pouch cells based on PTCDA/PPy/CNTs exhibit good mechanical flexibility in various mechanical states.This work inspires more rational designs of flexible and self-supporting organic cathodes,promoting the development of high-performance and wide-temperature adaptable wearable electronic devices.展开更多
In this study, an optimized high performance liquid chromatography-fluorescence detector (HPLC-FL) method for the determination of benzo[a]pyrene in edible oil was established. HPLC was performed with Thermo Fisher Sc...In this study, an optimized high performance liquid chromatography-fluorescence detector (HPLC-FL) method for the determination of benzo[a]pyrene in edible oil was established. HPLC was performed with Thermo Fisher Scientific C18 column (250 mm×4.6 mm, 5 μm) as the chromatographic column and acetonitrile and water as the mobile phase, and the excitation wavelength and emission wavelength of fluorescence detector were 286 and 430 nm, respectively. The response was high, and the linear range was 0.5-10.0 ng/ml. The lowest limit of detection was 0.11 ng/ml, and the average recovery was 92.5%. This method is suitable for quantitative analysis of benzo[a]pyrene content in edible oil.展开更多
Further improving the railway innovation capacity and technological strength is the important goal of the 14th Five-Year Plan for railway scientific and technological innovation.It includes promoting the deep integrat...Further improving the railway innovation capacity and technological strength is the important goal of the 14th Five-Year Plan for railway scientific and technological innovation.It includes promoting the deep integration of cutting-edge technologies with the railway systems,strengthening the research and application of intelligent railway technologies,applying green computing technologies and advancing the collaborative sharing of transportation big data.The high-speed rail system tasks need to process huge amounts of data and heavy workload with the requirement of ultra-fast response.Therefore,it is of great necessity to promote computation efficiency by applying High Performance Computing(HPC)to high-speed rail systems.The HPC technique is a great solution for improving the performance,efficiency,and safety of high-speed rail systems.In this review,we introduce and analyze the application research of high performance computing technology in the field of highspeed railways.These HPC applications are cataloged into four broad categories,namely:fault diagnosis,network and communication,management system,and simulations.Moreover,challenges and issues to be addressed are discussed and further directions are suggested.展开更多
The proposed controller incorporates FL （fuzzy logic） algorithm with ANN （artificial neural network）. ANFIS replaces the conventional PI controller, tuning the fuzzy inference system with a hybrid learning algorit...The proposed controller incorporates FL （fuzzy logic） algorithm with ANN （artificial neural network）. ANFIS replaces the conventional PI controller, tuning the fuzzy inference system with a hybrid learning algorithm. A tuning method is proposed for training of the neuro-fuzzy controller. The best rule base and the best training algorithm chosen produced high performance in the ANFIS controller. Simulation was done on Matlab Ver. 2010a. A case study was chopper-fed DC motor drive, in continuous and discrete modes. Satisfactory results show the ANFIS controller is able to control dynamic highly-nonlinear systems. Tuning it further improved the results.展开更多
A control system used in high performance liquid chromatograph(HPLC) was described.The control system adopting low pressure gradient elution was tested with different initial and end volume fractions,and four types of...A control system used in high performance liquid chromatograph(HPLC) was described.The control system adopting low pressure gradient elution was tested with different initial and end volume fractions,and four types of gradient elution curves.The experimental results verified the theoretical analyses of the applied method.This self-designed control system can achieve approving accuracy,repeatability and low cost,which has a bright outlook for domestic applications.展开更多
A time-of-flight (TOF) detector has been used in the BESIII experiment to provide charged particle identification. In this paper, we present a novel high performance differential amplifier, which has been designed for...A time-of-flight (TOF) detector has been used in the BESIII experiment to provide charged particle identification. In this paper, we present a novel high performance differential amplifier, which has been designed for amplifying the signals from the detectors. The preamplifier can amplify differential signals, which can help to eliminate the common mode pickup, and increase the signal-to-noise ratio (SNR). Bilinear gain is one of the features of this preamplifier, which greatly increases the dynamic range and avoids the dead time of the preamplifier. In order to describe the bilinear gain, a 4-parameter function is developed. And this 4-parameter function can also be used in the calibration of the time walk caused by the amplitude due to the bilinear gain. The preamplifier has a gain about 10V/V with a small signal and about 1.0V/V with a large signal. The rise time of the preamp is less than 2 ns.展开更多
A flow injection (FI) micro-column system coupled with high performance liquid chromatography (HPLC) was proposed for the pre-separation and determination of active organic component (ecdysterone) in traditional Chine...A flow injection (FI) micro-column system coupled with high performance liquid chromatography (HPLC) was proposed for the pre-separation and determination of active organic component (ecdysterone) in traditional Chinese medicine, Loulu. The factors influencing separation performance were investigated and optimized. Under the optimal conditions, the contents of ecdysterone in Loulu were determined by HPLC system using MeOH-H_2O (40: 60,V/V) as the mobile phase at a flow rate of 1. 0 mL/min. The calibration curve was linear in the range of 0. 5~ 100 mg/L of ecdysterone concentrations. The detection limit of the analyte was 0. 11mol/L(3) with a precision of 0. 38% RSD (n=7 f c= 10. 0 mg/L). The average recovery of the method was 98. 7%. The proposed method has been applied to determine ecdysterone in practical samples, and the determined values by both external standard method and standard addition method were in good agreement. Compared to the traditional solid extraction method, the system proposed has the advantages of simple procedure, good reproducibility, minimum volume requirement, reduction of matrix interference and low contamination risk.展开更多
基金supported by the Director’s Fund for the‘Climbing Plan’of the National Space Science Centre of the Chinese Academy of Sciences(No.E2PD10011S)the National Engineering Research Centre for Mobile Private Networks Project(No.BJTU20221102).
文摘This study begins with the fabrication and simulation of high-performance back-illuminated AlGaN-based solar-blind ultraviolet(UV)photodetectors.Based on the photodetectors,a low-noise,high-gain UV detection system circuit is designed and fabricated,enabling the detection,acquisition,and calibration of weak solar-blind UV signals.Experimental results demonstrate that under zero bias conditions,with a UV light power density of 3.45μW/cm^(2) at 260 nm,the sample achieves a peak responsivity(R)of 0.085 A·W^(−1),an external quantum efficiency(EQE)of 40.7%,and a detectivity(D^(*))of 7.46×10^(12) cm·Hz^(1/2)·W^(−1).The system exhibits a bandpass characteristic within the 240–280 nm wavelength range,coupled with a high signal-to-noise ratio(SNR)of 39.74 dB.
基金supported by the National Natural Science Foundation of China(Nos.52102088 and 22075026)support from Teli Fellowship,Beijing Institute of Technology,and facility support from Analysis&Testing Center,and Experimental Center of Materials Sciences&Engineering at Beijing Institute of Technology.
文摘MnCO_(3)represents a potentially high-capacity and low-cost anode candidate to replace graphite for enhancing energy density of commercial lithium-ion batteries,but it suffers from poor electrical conductivity and serious volumetric change,largely hindering its practical applications.
文摘ZFJ Textile Machinery Co.,Ltd.,established in 1949,is a key enterprise directly managed by China Hi-Tech Group Corporation and falls under the jurisdiction of China National Machinery Industry Corporation Limited(Sinomach).As a leading enterprise in the textile machinery manufacturing industry,ZFJ is dedicated to providing global customers with complete equipment solutions covering the entire industry chain.During this exhibition,ZFJ primarily highlights three key features:"high-performance fibers,green fibers,and intelligent equipment,"with a focus on showcasing nine types of products,spanning various textile equipment categories,including chemical fiber,specialty fiber,nonwoven,sizing,and dyeing machinery.
基金supported by Fujian Science and Technology Planning Projects of China(Nos.2022T3067 and 2023H0045)the Self-deployment Project Research Programs of Haixi Institutes,Chinese Academy of Sciences(No.CXZX-2022-JQ12)the Self-deployment project of XIREM(No.2023GG02).
文摘Lithium/fluorinated carbon(Li/CF_(x))batteries are greatly limited in their applications mostly due to poor rate performances.In this study,N,P co-doped biomass carbon was synthesized using melamine and phytic acid as doping sources,and the resulting product was then utilized as a precursor for CF_(x).The resulting fluorinated biomass carbon has a high degree of fluorination,exceeding the specific capacity of commercial fluorinated graphite while also demonstrating exceptional performance at high discharge rates.During the fluorination process,N,P-containing functional groups were removed from the crystalline lattice in the basal plane.This facilitates the formation of a defect-rich carbon matrix,enhancing the F/C ratio by improving the fluorinated active sites and obtaining more highly active semi-ionic bonds.Additionally,the abundant defects and porous structure promote Li^(+)diffusion.Density functional theory calculations indicated that doping modification effectively reduces the energy barrier for Li+migration,enhancing Li+transport efficiency.The prepared CF_(x)delivers material with a maximum specific capacity of 919 mAh·g^(-1),while maintaining a specific capacity of 702 mAh·g^(-1)at a high discharge current density of 20C(with a capacity retention rate of 76.4%).In this study,fluorinated N,P co-doped biomass carbon,exhibiting ultrahigh capacity and high-rate performance,was prepared for the first time,which can potentially advance the commercialization of CF_(x).
文摘A high-performance liquid chromatography(HPLC)method has been developed using a CAPCELL PAK ADME(150 mm×4.6 mm,5μm)as analytical column and a gradient elution with 15 min using acetonitrile and 0.1%(in volume fraction)phosphoric acid water(pH=2.2)as the mobile phase.Three active substances in cosmetics were quantitatively detected simultaneously at a detection wavelength of 265 nm.The linear ranges of β-nicotinamide mononucleotides,ergothioneine and nicotinamide are 10~200 mg/L,5~100 mg/L and 5~100 mg/L respectively and the detection limits of three components are 3.0 mg/L,1.5 mg/L and 1.5 mg/L respectively.The recovery rate is 97.1~104.9%,with RSD≤2.0%.The method was applied to quantitative analysis of five samples of cosmetics toner,lotion,cream,essence and gel and three samples of raw materials.The results showed that the results of β-nicotinamide mononucleotide and ergothioneine in five cosmetics were consistent with the product label,while nicotinamide was inconsistent with the label.The purity of the three raw material samples was 99.5%,99.7% and 100.8%respectively.This method offers high precision,accuracy and short analysis time,making it a reliable approach for studying three active ingredients in cosmetics and suitable for quality control of related functional ingredients.
基金financially supported by the National Natural Science Foundation of China(Nos.52075351,51604177)the National Key Research and Development Program of China(No.2019YFA0705701)+4 种基金the National Funded Postdoctoral Researcher Program(No.GZC20231762)the Major S&T Infrastructure Construction Project of Sichuan Province(No.2020-510000-73-01441847)the International S&T Innovation Cooperation Program of Sichuan Province(No.2020YFH0039)the Chengdu International S&T Cooperation Funded Project(Nos.2020-GH02-00006HZ,2022-GH02-00027-HZ)the“1000 Talents Plan”of Sichuan Province,and the Talent Introduction Program of Sichuan University(No.YJ201410)。
文摘Anode active materials involving transition metal oxides and sulfides are of great significance for high energy density lithium-ion batteries(LIBs),but the huge volume expansion and inferior electronic conductivity upon cycling critically constrain their further application.Herein,from a new perspective,a highly conductive and stable 3D flexible composite current collector is rationally designed by facilely electrodepositing metallic Ni thin layer onto the carbon cloth(CC/Ni),which endows the supported active materials with exceptional electronic conductivity and structural stability.In addition,the homogeneously distributed metallic Ni protrusions external CC can strongly bond with the active components,ensuring the structural integrity of electrodes upon cycling.More importantly,the 3D network structure with large specific surface area provides abundant space to alleviate the volume expansion and more active sites for electrochemical reactions.Therefore,taking Ni_(3)S_(2)nanosheet(Ni_(3)S_(2)NS)anode as an example,the prepared Ni_(3)S_(2)NS@CC/Ni electrode shows a high specific capacity of 2.32 mAh/cm^(2)at 1mA/cm^(2)and high capacity retention of 1.68 mAh/cm^(2)at a high rate of 8mA/cm^(2).This study provides a universal approach to obtain highly conductive and stable 3D flexible current collectors towards high performance metal-ion batteries beyond LIBs.
基金supported by the National Key Research and Development Program of China (Grant No. 2024YFB3211701)the National Natural Science Foundation of China (Grant Nos. T2222011, 62174026, and 12274234)+1 种基金the National Key Research and Development Program of China (Grant Nos. 2023YFB3611400 and 2019YFA0308000)the Fundamental Research Funds for the Central Universities (Grant No. 242023k30027)。
文摘The weak interlayer van der Waals(vdW) interactions in two-dimensional(2D) vdW materials enable sliding ferroelectricity as an effective strategy for modulating their intrinsic properties. In this work, we systematically investigate the influence of interlayer sliding on the electronic behavior of PtSe_(2) using density functional theory(DFT) calculations. Our results demonstrate that interlayer sliding induces a pronounced photocurrent spanning the short-wavelength infrared to visible spectral ranges. Remarkably, under an applied gate voltage, the sliding ferroelectric PtSe_(2) exhibits anomalously enhanced photovoltaic performance and an ultrahigh extinction ratio.Transmission spectral analysis reveals that this phenomenon originates from band structure modifications driven by energy-level transitions. Furthermore, the observed photocurrent enhancement via sliding ferroelectricity demonstrates universality across diverse platinum-based optoelectronic devices. This study introduces a novel paradigm for tailoring the intrinsic characteristics of 2D vdW semiconductors, expanding the design space for next-generation ferroelectric materials in advanced optoelectronic applications.
文摘With the most advanced and sophisticated technologies and equipment,NYBELT is one of the largest manufacturers of flat transmission belts in the world.Under the Certified Quality,Environment,Occupational Health&Safety,and Energy Standardized ISO Management System,NYBELT can produce all kinds of flat transmission belts,roller coverings and conveyor belts applicable to textile,printing&packaging,electronics and other industries.Due to the superior quality and the reasonable prices,we have become well known in providing high quality belting products and excellent service to customers all over the world.Our success in the past gives us the confidence to look into the future with great expectations.
基金supported by the National Science Fund for Distinguished Young Scholars(Grant No.T2225027)the National Key R&D Program of China(Grant No.2023YFA1608902).
文摘Maintaining stable high temperatures under pressure remains a challenge in high-pressure,high-temperature experiments using multi-anvil presses(MAPs).Temperature fluctuations exceeding 10℃ at high pressures are common and particularly problematic with LaCrO_(3) heaters,which can experience significant power fluctuations and even failure due to substantial resistance changes—an issue conventional thyristorcontrolled heating systems cannot effectively manage.To address this limitation,we have developed the Multi-Anvil Stable Temperature controller(MASTer),a high-performance heating system optimized for MAP experiments.MASTer enables precise,high-speed measurement of heating parameters and power output control,incorporating a gentle regulation strategy to enhance stability.It ensures consistent heating across various heater types,including LaCrO_(3),with power fluctuations limited to±0.1 W and temperature fluctuations to within±2℃ in most cases.The design,operating principles,user interface,functionality,and performance of the heating system are discussed in detail.
基金supported by the National Natural Science Foundation of China(Nos.51938005,52090082,and 52378395)the National Key Research and Development Program of China(No.2023YFB2604402).
文摘This study aims to assess the comprehensive strengthening effect of a steel-ultra high performance concrete(UHPC)composite strengthening method.The axial force-moment interaction curve(N-M curve)was calculated in a novel way,using cross-sectional strains at ultimate states as well as real-time stress measurements for each material.The enclosed area of the N-M curve was defined as a comprehensive performance index for the system.We validate our approach with comparisons to numerical modeling and full-scale four-point bending experiments.Additionally,strengthening effects were compared for different sagging and hogging moments based on material stress responses,and the impact of various strengthening parameters was analyzed.We find that the N-M curve of the strengthened cross-section envelops that of the un-strengthened cross-section.Notably,improvements in flexural capacity are greater under sagging moments during the large eccentric failure stage,and greater under hogging moments during the small eccentric failure stage.This discrepancy is attributed to the strength utilization of strengthening materials.These findings provide a reference for understanding the strengthening effects and parameters of steel-UHPC composite.
基金supported by National Natural Science Foundation of China(Grant No.52225503)Key Research and Development Pro-gram of Jiangsu Province(Grant Nos.BE2022069 and BE2022069-1)+2 种基金The Pre-research Project of Civil Aerospace Technology(Grant No.D020302)Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX23_0366)State Key Laboratory of Mechanics and Control for Aerospace Structures(Grant No.MCAS-S-0423G01).
文摘Significant contributions have been made to understanding the processing of various metal materials using laser powder bed fusion (LPBF) for the design and fabrication of high-performance metal components in many fields. For laser additive manufacturing, aluminum-based materials are regarded as difficult-to-fabricate materials be- cause of their special physical properties, including low density, low laser absorption, high thermal conductivity, and ease of oxidation. Currently, LPBF-formed structural materials require high densification, fine grains, high specific strength, high ductility, and optimized physical or chemical properties. Therefore, comprehensive un- derstanding of the fabrication and performance of Al-based materials processed by LPBF is of significant value. This paper covers emerging research on aluminum-based materials using LPBF, providing an overall view of the basic scientific mechanisms behind manufacturing. The state-of-the-art researches of aluminum-based materials for LPBF formability as well as the microstructures, properties and corresponding metallurgical mechanisms are reviewed. The mechanisms of some of the main defects (pores, cracks, balling, and oxide inclusions) and control measures are also discussed. A summary and outlook for the further development of Al-based materials for LPBF are addressed.
基金The authors acknowledge the financial support by the National Natural Science Foundation of China(52161145408 and 21975038)the Research and Innovation Team Project of Dalian University of Technology(DUT2022TB10)+2 种基金the Fundamental Research Funds for the Central Universities(DUT22QN213)the Innovation Technology Fund(MRP/040/21X)the Green Technology Fund(GTF202020164)for their financial support。
文摘All-inorganic CsPbIBr_(2) perovskite has attracted widespread attention in photovoltaic and other optoelectronic devices because of its superior thermal stability.However,the deposition of high-quality solutionprocessed CsPbIBr_(2) perovskite films with large thicknesses remains challenging.Here,we develop a triple-component precursor(TCP) by employing lead bromide,lead iodide,and cesium bromide,to replace the most commonly used double-component precursor(DCP) consisting of lead bromide and cesium iodide.Remarkably,the TCP system significantly increases the solution concentration to 1.3 M,leading to a larger film thickness(~390 nm) and enhanced light absorption.The resultant CsPbIBr_(2) films were evaluated in planar n-i-p structured solar cells,which exhibit a considerably higher optimal photocurrent density of 11.50 mA cm^(-2) in comparison to that of DCP-based devices(10.69 mA cm^(-2)).By adopting an organic surface passivator,the maximum device efficiency using TCP is further boosted to a record efficiency of 12.8% for CsPbIBr_(2) perovskite solar cells.
基金Shuangqiang Chen gratefully acknowledges the NationalNatural Science Foundation ofChina(21975154,22179078)Zhejiang Provincial Natural Science Founda-tion of China(LY24E020002)+3 种基金Shanghai MunicipalEducation Commission(Innovation Program:2019-01-07-00-09-E00021)the Innovative Research Team of High-level Local Universities in Shanghai.Bing Sunwould like to thank the financial support from ARCthrough the ARC Future Fellowship(FT220100561)YaoXiao would like to thank the financial support from theNatural Science Foundation of Zhejiang Province(LQ23E020002)the Wenzhou Key Scientific andTechnological Innovation Research Project(ZG2023053)
文摘Flexible electrode design with robust structure and good performance is one of the priorities for flexible batteries to power emerging wearable electronics,and organic cathode materials have become contenders for flexible self-supporting electrodes.However,issues such as easy electrolyte solubility and low intrinsic conductivity contribute to high polarization and rapid capacity decay.Herein,we have designed a flexible self-supporting cathode based on perylene-3,4,9,10-tetracarboxylic dianhydride(PTCDA),interfacial engineering enhanced by polypyrrole(PPy),and carbon nanotubes(CNTs),forming the interconnected and flexible PTCDA/PPy/CNTs using polymerization reaction and vacuum filtration methods,effectively curbing those challenges.When used as the cathode of sodium-ion batteries,PTCDA/PPy/CNTs exhibit excellent rate capability(105.7 mAh g^(−1) at 20 C),outstanding cycling stability(79.4%capacity retention at 5 C after 500 cycles),and remarkable wide temperature application capability(86.5 mAh g^(−1) at−30℃ and 115.4 mAh g^(−1) at 60℃).The sodium storage mechanism was verified to be a reversible oxidation reaction between two Na+ions and carbonyl groups by density functional theory calculations,in situ infrared Fourier transform infrared spectroscopy,and in situ Raman spectroscopy.Surprisingly,the pouch cells based on PTCDA/PPy/CNTs exhibit good mechanical flexibility in various mechanical states.This work inspires more rational designs of flexible and self-supporting organic cathodes,promoting the development of high-performance and wide-temperature adaptable wearable electronic devices.
文摘In this study, an optimized high performance liquid chromatography-fluorescence detector (HPLC-FL) method for the determination of benzo[a]pyrene in edible oil was established. HPLC was performed with Thermo Fisher Scientific C18 column (250 mm×4.6 mm, 5 μm) as the chromatographic column and acetonitrile and water as the mobile phase, and the excitation wavelength and emission wavelength of fluorescence detector were 286 and 430 nm, respectively. The response was high, and the linear range was 0.5-10.0 ng/ml. The lowest limit of detection was 0.11 ng/ml, and the average recovery was 92.5%. This method is suitable for quantitative analysis of benzo[a]pyrene content in edible oil.
基金supported in part by the Talent Fund of Beijing Jiaotong University(2023XKRC017)in part by Research and Development Project of China State Railway Group Co.,Ltd.(P2022Z003).
文摘Further improving the railway innovation capacity and technological strength is the important goal of the 14th Five-Year Plan for railway scientific and technological innovation.It includes promoting the deep integration of cutting-edge technologies with the railway systems,strengthening the research and application of intelligent railway technologies,applying green computing technologies and advancing the collaborative sharing of transportation big data.The high-speed rail system tasks need to process huge amounts of data and heavy workload with the requirement of ultra-fast response.Therefore,it is of great necessity to promote computation efficiency by applying High Performance Computing(HPC)to high-speed rail systems.The HPC technique is a great solution for improving the performance,efficiency,and safety of high-speed rail systems.In this review,we introduce and analyze the application research of high performance computing technology in the field of highspeed railways.These HPC applications are cataloged into four broad categories,namely:fault diagnosis,network and communication,management system,and simulations.Moreover,challenges and issues to be addressed are discussed and further directions are suggested.
文摘The proposed controller incorporates FL （fuzzy logic） algorithm with ANN （artificial neural network）. ANFIS replaces the conventional PI controller, tuning the fuzzy inference system with a hybrid learning algorithm. A tuning method is proposed for training of the neuro-fuzzy controller. The best rule base and the best training algorithm chosen produced high performance in the ANFIS controller. Simulation was done on Matlab Ver. 2010a. A case study was chopper-fed DC motor drive, in continuous and discrete modes. Satisfactory results show the ANFIS controller is able to control dynamic highly-nonlinear systems. Tuning it further improved the results.
基金the National High Technology Research and Development Program (863) of China(No. 2009AA04Z326)the National Natural Science Foundation of China (Nos. 60671059, 60871091 and60588101)+1 种基金the National Basic Research Program (973) of China (Nos. 2005CB724302 and 2005CB724303)the 111 Project from the Ministry of Education of China(No. B08020)
文摘A control system used in high performance liquid chromatograph(HPLC) was described.The control system adopting low pressure gradient elution was tested with different initial and end volume fractions,and four types of gradient elution curves.The experimental results verified the theoretical analyses of the applied method.This self-designed control system can achieve approving accuracy,repeatability and low cost,which has a bright outlook for domestic applications.
基金The project supported by the major upgrade program of the Beijing Electron Positron Collider Ⅱ
文摘A time-of-flight (TOF) detector has been used in the BESIII experiment to provide charged particle identification. In this paper, we present a novel high performance differential amplifier, which has been designed for amplifying the signals from the detectors. The preamplifier can amplify differential signals, which can help to eliminate the common mode pickup, and increase the signal-to-noise ratio (SNR). Bilinear gain is one of the features of this preamplifier, which greatly increases the dynamic range and avoids the dead time of the preamplifier. In order to describe the bilinear gain, a 4-parameter function is developed. And this 4-parameter function can also be used in the calibration of the time walk caused by the amplitude due to the bilinear gain. The preamplifier has a gain about 10V/V with a small signal and about 1.0V/V with a large signal. The rise time of the preamp is less than 2 ns.
基金Education Ministy Foundation for Chinese Returned Scholars and Nature Science Foundation of Hubeiprovince!98J054
文摘A flow injection (FI) micro-column system coupled with high performance liquid chromatography (HPLC) was proposed for the pre-separation and determination of active organic component (ecdysterone) in traditional Chinese medicine, Loulu. The factors influencing separation performance were investigated and optimized. Under the optimal conditions, the contents of ecdysterone in Loulu were determined by HPLC system using MeOH-H_2O (40: 60,V/V) as the mobile phase at a flow rate of 1. 0 mL/min. The calibration curve was linear in the range of 0. 5~ 100 mg/L of ecdysterone concentrations. The detection limit of the analyte was 0. 11mol/L(3) with a precision of 0. 38% RSD (n=7 f c= 10. 0 mg/L). The average recovery of the method was 98. 7%. The proposed method has been applied to determine ecdysterone in practical samples, and the determined values by both external standard method and standard addition method were in good agreement. Compared to the traditional solid extraction method, the system proposed has the advantages of simple procedure, good reproducibility, minimum volume requirement, reduction of matrix interference and low contamination risk.
