China's High Performance Computer Standard Commission was established on March 28, 2007, under the guidance of the Science and Technology Bureau of the Ministry of Information Industry. It will prepare relevan... China's High Performance Computer Standard Commission was established on March 28, 2007, under the guidance of the Science and Technology Bureau of the Ministry of Information Industry. It will prepare relevant professional standards on high performance computers to break through the monopoly in the field by foreign manufacturers and vendors.……展开更多
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
High performance computers provide strategic computing power in the construction of national economy and defense, and become one of symbols of the country＇s overall strength. Over 30 years, with the supports of gover...High performance computers provide strategic computing power in the construction of national economy and defense, and become one of symbols of the country＇s overall strength. Over 30 years, with the supports of governments, the technology of high performance computers is in the process of rapid development, during which the computing performance increases nearly 3 million times and the processors number expands over 10 hundred thousands times. To solve the critical issues related with parallel efficiency and scalability, scientific researchers pursued extensive theoretical studies and technical innovations. The paper briefly looks back the course of building high performance computer systems both at home and abroad, and summarizes the significant breakthroughs of international high performance computer technology. We also overview the technology progress of China in the area of parallel computer architecture, parallel operating system and resource management, parallel compiler and performance optimization, environment for parallel programming and network computing. Finally, we examine the challenging issues, ＂memory wall＂, system scalability and ＂power wall＂, and discuss the issues of high productivity computers, which is the trend in building next generation high performance computers.展开更多
High performance computer （HPC） is a complex huge system, of which the architecture design meets increasing difficulties and risks. Traditional methods, such as theoretical analysis, component-level simulation and s...High performance computer （HPC） is a complex huge system, of which the architecture design meets increasing difficulties and risks. Traditional methods, such as theoretical analysis, component-level simulation and sequential simulation, are not applicable to system-level simulations of HPC systems. Even the parallel simulation using large-scale parallel machines also have many difficulties in scalability, reliability, generality, as well as efficiency. According to the current needs of HPC architecture design, this paper proposes a system-level parallel simulation platform： ArchSim. We first introduce the architecture of ArchSim simulation platform which is composed of a global server （GS）, local server agents （LSA） and entities. Secondly, we emphasize some key techniques of ArchSim, including the synchronization protocol, the communication mechanism and the distributed checkpointing/restart mechanism. We then make a synthesized test of some main performance indices of ArchSim with the phold benchmark and analyze the extra overhead generated by ArchSim. Finally, based on ArchSim, we construct a parallel event-driven interconnection network simulator and a system-level simulator for a small scale HPC system with 256 processors. The results of the performance test and HPC system simulations demonstrate that ArchSim can achieve high speedup ratio and high scalability on parallel host machine and support system-level simulations for the architecture design of HPC systems.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
With supercomputers developing towards exascale, the number of compute cores increases dramatically, making more complex and larger-scale applications possible. The input/output （I/O） requirements of large-scale app...With supercomputers developing towards exascale, the number of compute cores increases dramatically, making more complex and larger-scale applications possible. The input/output （I/O） requirements of large-scale applications, workflow applications, and their checkpointing include substantial bandwidth and an extremely low latency, posing a serious challenge to high performance computing （HPC） storage systems. Current hard disk drive （HDD） based underlying storage systems are becoming more and more incompetent to meet the requirements of next-generation exascale supercomputers. To rise to the challenge, we propose a hierarchical hybrid storage system, on-line and near-line file system （ONFS）. It leverages dynamic random access memory （DRAM） and solid state drive （SSD） in compute nodes, and HDD in storage servers to build a three-level storage system in a unified namespace. It supports portable operating system interface （POSIX） semantics, and provides high bandwidth, low latency, and huge storage capacity. In this paper, we present the technical details on distributed metadata management, the strategy of memory borrow and return, data consistency, parallel access control, and mechanisms guiding downward and upward migration in ONFS. We implement an ONFS prototype on the TH-1A supercomputer, and conduct experiments to test its I/O performance and scalability. The results show that the bandwidths of single-thread and multi-thread ＇read＇/＇write＇ are 6-fold and 5-fold better than HDD-based Lustre, respectively. The I/O bandwidth of data-intensive applications in ONFS can be 6.35 timcs that in Lustre.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
Moisture enabled electric generation(MEG)is an innovative green energy technology that converts the chemical potential energy of atmospheric water vapor into electricity.Here,we report a novel molecular-level zero-dim...Moisture enabled electric generation(MEG)is an innovative green energy technology that converts the chemical potential energy of atmospheric water vapor into electricity.Here,we report a novel molecular-level zero-dimensional(0D)perovskite-based MEG device that efficiently harvests ambient moisture to generate electric power,which makes perovskite a new kind of potential MEG.The 0D perovskite,DAP₂PbI₆,(where DAP is 1,3-bis(ammonium)-2-hydroxypropane diiodide.)features a unique hydrogen-bonding network formed between its ammonium(–NH_(3)^(+))and hydroxyl(–OH)groups,imparting water stability and remarkable hydrophilicity.Such robust interactions facilitate water adsorption and the subsequent release of hydrogen ions under humid conditions.These protonic species establish an ion gradient,driving a directional current via the ion-gradient diffusion–induced voltage.We demonstrated a maximum volumetric power density of 45 mW·cm^(–3)—substantially exceeding previously reported values for protein-or carbon-based MEG.Additionally,SEM and AFM analyses confirm DAP₂PbI₆is stable upon moisture exposure,while temperature-dependent impedance spectroscopy and theoretical calculations reveal that proton diffusion is the primary mechanism for the observed moisture-driven electricity.These findings underscore the promise of hydrophilic 0D perovskite materials for high-efficiency MEG and pave the way for next-generation sustainable power applications.展开更多
文摘 China's High Performance Computer Standard Commission was established on March 28, 2007, under the guidance of the Science and Technology Bureau of the Ministry of Information Industry. It will prepare relevant professional standards on high performance computers to break through the monopoly in the field by foreign manufacturers and vendors.……
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The paper is partly supported by the National Natural Science Foundation of China under Grant No. 69933030. Acknowledgement We have to indicate with great regret that some excellent researches may not be mentioned in this paper because of our limited knowledge and the wide area related with high performance computer technology.
文摘High performance computers provide strategic computing power in the construction of national economy and defense, and become one of symbols of the country＇s overall strength. Over 30 years, with the supports of governments, the technology of high performance computers is in the process of rapid development, during which the computing performance increases nearly 3 million times and the processors number expands over 10 hundred thousands times. To solve the critical issues related with parallel efficiency and scalability, scientific researchers pursued extensive theoretical studies and technical innovations. The paper briefly looks back the course of building high performance computer systems both at home and abroad, and summarizes the significant breakthroughs of international high performance computer technology. We also overview the technology progress of China in the area of parallel computer architecture, parallel operating system and resource management, parallel compiler and performance optimization, environment for parallel programming and network computing. Finally, we examine the challenging issues, ＂memory wall＂, system scalability and ＂power wall＂, and discuss the issues of high productivity computers, which is the trend in building next generation high performance computers.
基金supported by the National High Technology Research and Development 863 Program of China under Grant No. 2007AA01Z117the National Basic Research 973 Program of China under Grant No.2007CB310900
文摘High performance computer （HPC） is a complex huge system, of which the architecture design meets increasing difficulties and risks. Traditional methods, such as theoretical analysis, component-level simulation and sequential simulation, are not applicable to system-level simulations of HPC systems. Even the parallel simulation using large-scale parallel machines also have many difficulties in scalability, reliability, generality, as well as efficiency. According to the current needs of HPC architecture design, this paper proposes a system-level parallel simulation platform： ArchSim. We first introduce the architecture of ArchSim simulation platform which is composed of a global server （GS）, local server agents （LSA） and entities. Secondly, we emphasize some key techniques of ArchSim, including the synchronization protocol, the communication mechanism and the distributed checkpointing/restart mechanism. We then make a synthesized test of some main performance indices of ArchSim with the phold benchmark and analyze the extra overhead generated by ArchSim. Finally, based on ArchSim, we construct a parallel event-driven interconnection network simulator and a system-level simulator for a small scale HPC system with 256 processors. The results of the performance test and HPC system simulations demonstrate that ArchSim can achieve high speedup ratio and high scalability on parallel host machine and support system-level simulations for the architecture design of HPC systems.
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.
基金Project supported by the National Key Research and Development Program of China(No.2016YFB0200402)
文摘With supercomputers developing towards exascale, the number of compute cores increases dramatically, making more complex and larger-scale applications possible. The input/output （I/O） requirements of large-scale applications, workflow applications, and their checkpointing include substantial bandwidth and an extremely low latency, posing a serious challenge to high performance computing （HPC） storage systems. Current hard disk drive （HDD） based underlying storage systems are becoming more and more incompetent to meet the requirements of next-generation exascale supercomputers. To rise to the challenge, we propose a hierarchical hybrid storage system, on-line and near-line file system （ONFS）. It leverages dynamic random access memory （DRAM） and solid state drive （SSD） in compute nodes, and HDD in storage servers to build a three-level storage system in a unified namespace. It supports portable operating system interface （POSIX） semantics, and provides high bandwidth, low latency, and huge storage capacity. In this paper, we present the technical details on distributed metadata management, the strategy of memory borrow and return, data consistency, parallel access control, and mechanisms guiding downward and upward migration in ONFS. We implement an ONFS prototype on the TH-1A supercomputer, and conduct experiments to test its I/O performance and scalability. The results show that the bandwidths of single-thread and multi-thread ＇read＇/＇write＇ are 6-fold and 5-fold better than HDD-based Lustre, respectively. The I/O bandwidth of data-intensive applications in ONFS can be 6.35 timcs that in Lustre.
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 by the National Natural Science Foundation of China(Nos.52102217,52102332)the Natural Science Foundation of Fujian Province(2021J05120).
文摘Moisture enabled electric generation(MEG)is an innovative green energy technology that converts the chemical potential energy of atmospheric water vapor into electricity.Here,we report a novel molecular-level zero-dimensional(0D)perovskite-based MEG device that efficiently harvests ambient moisture to generate electric power,which makes perovskite a new kind of potential MEG.The 0D perovskite,DAP₂PbI₆,(where DAP is 1,3-bis(ammonium)-2-hydroxypropane diiodide.)features a unique hydrogen-bonding network formed between its ammonium(–NH_(3)^(+))and hydroxyl(–OH)groups,imparting water stability and remarkable hydrophilicity.Such robust interactions facilitate water adsorption and the subsequent release of hydrogen ions under humid conditions.These protonic species establish an ion gradient,driving a directional current via the ion-gradient diffusion–induced voltage.We demonstrated a maximum volumetric power density of 45 mW·cm^(–3)—substantially exceeding previously reported values for protein-or carbon-based MEG.Additionally,SEM and AFM analyses confirm DAP₂PbI₆is stable upon moisture exposure,while temperature-dependent impedance spectroscopy and theoretical calculations reveal that proton diffusion is the primary mechanism for the observed moisture-driven electricity.These findings underscore the promise of hydrophilic 0D perovskite materials for high-efficiency MEG and pave the way for next-generation sustainable power applications.
