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Preparation of Cu-based Bulk Metallic Glass Matrix Composites

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Journal of Materials Science & Technology 2006年第1期22卷 73-77页

作者： yufeng SUN Yuren WANG Bingchen WEI Weihuo LI Research Center for Materials Department of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450002 China National Microgravity Laboratory Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China

Cu47Ti34Zr11Ni8 bulk metallic glass （BMG） matrix composites containing in situ formed TiC particles and 5-TiCu dendrite phase were developed by copper mold cast. The thermal stability and microstructure of the composites are investigated. Room temperature compression tests reveal that the composite samples exhibit higher fracture strength and distinct plastic strain of 0.2%-0.5%, comparing with that of the corresponding Cu47Ti34Zr11Ni8 monolithic BMG.

关键词： Bulk metallic glasses Shear bands Mechanical properties Composites

Joint Optimization of Trajectory and Task Offloading for Cellular-Connected Multi-UAV Mobile Edge Computing

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Chinese Journal of Electronics 2024年第3期33卷 823-832页

作者： Jingming XIA yufeng LIU Ling TAN School of Artificial Intelligence Nanjing University of Information Science and Technology Engineering Research Center of Digital Forensics Ministry of Education Nanjing University of Information Science and Technology

Since the computing capacity and battery energy of unmanned aerial vehicle(UAV) are constrained,UAV as aerial user is hard to handle the high computational complexity and time-sensitive *** paper investigates a cellular-connected multi-UAV network supported by mobile edge *** UAVs carrying tasks fly from a given initial position to a termination position within a specified *** handle the large number of tasks carried by UAVs,we propose a energy cost of all UAVs based problem to determine how many tasks should be offloaded to high-altitude balloons(HABs) for computing,where UAV-HAB association,the trajectory of UAV,and calculation task splitting are jointly ***,the formulated problem has nonconvex ***,an efficient iterative algorithm by applying successive convex approximation and the block coordinate descent methods is put ***,in each iteration,the UAV-HAB association,calculation task splitting,and UAV trajectory are alternately ***,for the nonconvex UAV trajectory optimization problem,an approximate convex optimization problem is *** numerical results indicate that the scheme of this paper proposed is guaranteed to converge and also significantly reduces the entire power consumption of all UAVs compared to the benchmark schemes.

关键词： Energy consumption Multi-access edge computing Costs Power demand Autonomous aerial vehicles Iterative algorithms Convex functions

Self assembled electron blocking and lithiophilic interface towards dendrite-free solid-state lithium battery

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Chinese Chemical Letters 2024年第4期35卷 220-225页

作者： Caixia Li Yi Qiu yufeng Zhao Wuliang Feng Institute for Sustainable Energy&College of Sciences Shanghai UniversityShanghai 200444China Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Nankai UniversityTianjin 300071China

The poor interfacial contact is one of the biggest challenges that solid-state lithium batteries suffer *** the solid-state electrolyte surface energy by transforming the interface from lithiophobic to lithiophilic is effective to promote the interfacial contact, but electronic conductive interphases usually increase the risk of electron attack, thus leading to uncontrollable Li dendrite growth. Herein, we propose a self-assembled thermodynamic stable Li I interphase to simultaneously improve the interfacial contact between the garnet electrolyte Li_7La_(3)Zr_(2)O_(12)(LLZO) and Li anode, and prohibit the electron attack. The direct contact between LLZO and Li and the high temperature Li melting process was ascribed to Zr4+reduction, which facilitated Li dendrite formation and propagation. With the modification of the high lithiophilic I_(2) thin film, the area specific interfacial resistance of LLZO/Li was reduced from 1525 Ω/cm^(2) to 57 Ω/cm^(2). More importantly, LLZO was protected from being reduced due to the outstanding electronic insulativity of the Li I interphase, which leaded to a high critical current density of 1.2/7.0 m A/cm^(2) in the time/capacity-constant modes, respectively.

关键词： Li_7La_(3)Zr_(2)O_(12) LiI interphase Interfacial contact Li dendrite Thermodynamic stable

基于山西老陈醋传统工艺固态发酵体系时空异质性分析解析主要风味物质形成规律

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食品科学 2025年第2期46卷 164-170页

作者：申瑾周景丽郎繁繁闫裕峰王利夏瑶瑶李杰张峰王晨苑郑宇食醋发酵科学与工程山西省重点实验室山西太原030400 山西紫林醋业股份有限公司山西太原030040 天津市微生物代谢与发酵过程控制技术工程中心天津300457 天津科技大学生物工程学院天津300457

以山西老陈醋固态发酵过程为研究对象,采用宏基因组学和顶空固相微萃取-气相色谱-质谱联用技术,分别对不同空间发酵过程的醋醅理化特征、风味物质和微生物群落组成进行分析。结果表明:不同空间位置醋醅的水分、温度均具有显著性差异,发... 详细信息

以山西老陈醋固态发酵过程为研究对象,采用宏基因组学和顶空固相微萃取-气相色谱-质谱联用技术,分别对不同空间发酵过程的醋醅理化特征、风味物质和微生物群落组成进行分析。结果表明:不同空间位置醋醅的水分、温度均具有显著性差异,发酵过程共检测到93种挥发性风味物质,总挥发性物质含量依次为上层>中层>下层。上、中、下层总酸均与Proteus、Salinicoccus、Staphylococcus、Klebsiella显著负相关(P<0.05),从而影响微生物生长代谢,下层水分显著影响Proteus、Salinicoccus、Saccharomyces、Staphylococcus、Klebsiella生长代谢(P<0.05)。Proteus、Saccharomyce、Staphylococcus、Klebsiella与发酵过程理化指标密切相关,上层醋醅中Proteus、Salinicoccus、Saccharomyce、Staphylococcus、Klebsiella微生物生长代谢促进了亚油酸乙酯、油酸乙酯等酯类化合物的生成,中、下层的发酵条件则抑制了部分酯类物质的生成。本研究从时空异质的角度解析了山西老陈醋发酵特性,阐明了风味物质形成规律,有助于全面阐明山西老陈醋酿造机理。

关键词：醋醅宏基因组学微生物理化因子挥发性风味相关性分析

A granular adsorbent-supported Fe/Ni nanoparticles activating persulfate system for simultaneous adsorption and degradation of ciprofloxacin

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Chinese Journal of Chemical Engineering 2020年第4期28卷 1077-1084页

作者： Jiwei Liu yufeng Du Wuyang Sun Quanchao Chang Changsheng Peng Key Lab of Marine Environmental Science and Ecology Ministry of EducationOcean University of ChinaQingdao 266100China School of Environment Tsinghua UniversityBeijing 100084China School of Environmental and Chemical Engineering Zhaoqing UniversityZhaoqing 526061China

In this work,Fe/Ni nanoparticles were produced through Fe(II)and Ni(II)reduction by NaBH4 and they were stabilized by a kind of prepared granular adsorbent(Fe/Ni@PGA).Fe/Ni@PGA as an environment-friendly activator was used to activate persulfate(PS)for the removal of ciprofloxacin from aqueous ***/Ni@PGA was systematically characterized via Brunauer-Emmett-Teller(BET)method,X-ray diffraction(XRD),scanning electron microscopy(SEM),and Fourier transform infrared spectroscopy(FTIR).The effects of PS concentration,initial solution pH,Fe/Ni@PGA dosage,initial ciprofloxacin concentration,reaction temperature,anions,and natural organic matters on the removal of ciprofloxacin by Fe/Ni@PGA/PS were *** removal efficiency of ciprofloxacin by Fe/Ni@PGA/PS was 93.24%under an initial pH of 3.0,PS concentration of 10 mM,Fe/Ni@PGA dosage of 0.1 g,and reaction temperature of 30℃.Fe/Ni@PGA could still exhibit high catalytic activity after nine cycles of *** removal mechanisms for ciprofloxacin by the Fe/Ni@PGA/PS system were *** summary,the Fe/Ni@PGA/PS system could be applied as a promising technology for ciprofloxacin removal.

关键词： Fe/Ni@PGA Ciprofloxacin Persulfate Sulfate radical Oxidation Adsorption

Vegetation dynamics of coal mining city in an arid desert region of Northwest China from 2000 to 2019

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Journal of Arid Land 2021年第5期13卷 534-547页

作者： ZHOU Siyuan DUAN yufeng ZHANG Yuxiu GUO Jinjin School of Chemical&Environmental Engineering China University of Mining and Technology(Beijing)Beijing 100083China

Coal mining has led to serious ecological damages in arid desert region of Northwest ***,effects of climatic factor and mining activity on vegetation dynamics and plant diversity in this region remain *** City located in the arid desert region of Northwest China is an industrial city and dominated by coal *** on Landsat data and field investigation in Wuhai City,we analyzed the vegetation dynamics and the relationships with climate factors,coal mining activity and ecological restoration projects from 2000 to *** showed that vegetation in Wuhai City mostly consisted of desert plants,such as Caragana microphylla,Tetraena mongolica and Achnatherum *** the vegetation fractional coverage(VFC)and greenness rate of change(GRC)showed that vegetation was slightly improved during the study *** difference vegetation index(NDVI)was positively correlated with annual mean precipitation,relative humidity and annual mean temperature,indicating that these climate factors might play important roles in the improved *** coverage and plant diversity around the coal mining area were reduced by coal mining,while the implementation of ecological restoration projects improved the vegetation coverage and plant *** results suggested that vegetation in the arid desert region was mainly affected by climate factors,and the implementation of ecological restoration projects could mitigate the impacts of coal mining on vegetation and ecological environment.

关键词： climate factor ecological restoration normalized difference vegetation index(NDVI) plant diversity Wuhai City

Construction of PMIA@PAN/PVDF-HFP/TiO_(2) coaxial fibrous separator with enhanced mechanical strength and electrolyte affinity for lithium-ion batteries

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Chinese Chemical Letters 2023年第12期34卷 257-262页

作者： Huilan Li Tingting Feng yufeng Liang Mengqiang Wu School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu 611731China

Poly(m-phthaloyl-m-phenylenediamine)(PMIA)is promising as the separator in lithium-ion batteries(LIBs)for its excellent thermostability,insulation and self-extinguishing ***,its low mechanical strength and poor electrolyte affinity limit its application in *** this work,a new PMIA@polyacrylonitrile-polyvinylidene fluoride hexafluoropropylene-titanium dioxide(PMIA@PAN/PVDFHFP/TiO_(2))composite fibrous separator with a coaxial core-shell structure was developed by combining coaxial electrospinning,hot pressing,and heat treatment *** separator not only inherits the exceptional thermostability of PMIA,showing no evident thermal shrinkage at 220 ℃,but also reveals improved mechanical strength(29.7 MPa)due to the formation of firm connections between fibers with the melted ***,the massive polar groups in PVDF-HFP play a vital role in improving the electrolyte affinity,which renders the separator a high ionic conductivity of 1.36×10^(-3)s/***,the LIBs with PMIA@PAN/PVDF-HFP/TiO_(2)separators exhibited excellent cycling and rate performance at 25℃,and a high capacity retention rate(76.2%)at 80℃for 200 cycles at 1 ***,the lithium metal symmetric battery assembled by the separator showed a small overpotential,indicating that the separator had a role in inhibiting lithium *** short,the PMIA@PAN/PVDF-HFP/TiO_(2) separator possesses a wide application prospect in the domain of LIBs.

关键词： Poly(m-phthaloyl-m-phenylenediamine)(PMIA) Fibrous separator Coaxial electrospinning Mechanical strength Lithium-ion batteries

Requirements ranking based on crowd-sourcing high-end product USs

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Journal of Systems Engineering and Electronics 2024年第1期35卷 94-104页

作者： MA yufeng DOU Yajie XU Xiangqian JIA Qingyang TAN Yuejin College of Systems Engineering National University of Defense TechnologyChangsha 410003China

Based on the characteristics of high-end products,crowd-sourcing user stories can be seen as an effective means of gathering requirements,involving a large user base and generating a substantial amount of unstructured *** key challenge lies in transforming abstract user needs into specific ones,requiring integration and ***,we propose a topic mining-based approach to categorize,summarize,and rank product requirements from user ***,after determining the number of story categories based on py LDAvis,we initially classify“I want to”phrases within user ***,classic topic models are applied to each category to generate their names,defining each post-classification user story category as a ***,a weighted ranking function is devised to calculate the importance of each ***,we validate the effectiveness and feasibility of the proposed method using 2966 crowd-sourced user stories related to smart home systems.

关键词： high-end product complex system crowd-sourcing user stories topic mining requirements ranking

Experimental results for the vapor-liquid equilibria of 0(formaldehyde+1,3,5-trioxane+methanol+salt+water)systems and comparison with predictions

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Chinese Journal of Chemical Engineering 2021年第4期34卷 291-300页

作者： Xianming Zhang Mengchen Li yufeng Hu Zhichang Liu Shuqin Mo State Key Laboratory of Heavy Oil Processing and High Pressure Fluid Phase Behavior&Property Research Laboratory China University of PetroleumBeijing 102249China School of Chemical Engineering Ordos Institute of TechnologyOrdos 017000China PetroChina Petrochemical Research Institute Science Base PetroChina Beijing 102206China

The salt effect on the vaporliquid phase equilibrium(VLE)of solvent mixtures is of significant interest in the industrial production of 1,3,*** data for the VLE of quinary systems(formaldehyde+1,3,5trioxane+methanol+salt+water)and their ternary subsystems(formaldehyde+salt+water),(1,3,5trioxane+salt+water),and(methanol+salt+water)were systematic measured under atmospheric *** salts considered included KBr,NaNO_(3),and CaCl_(2).The extended UNIFAC model was used to describe the VLE of the saltcontaining reactive *** model parameters were determined from the experimental VLE data of ternary systems or obtained from the literature,and then were used to predict the VLE of systems(1,3,5trioxane+KBr+water),(methanol+KBr+water),(formaldehyde+KBr+water),and(formaldehyde+1,3,5trioxane+methanol+salt+water)with salt=KBr,NaNO_(3),and CaCl_(2).The predicted results showed good agreements with the measured ***,the model was used to uncover the salt effect on the VLE of these multisolvent reactive systems.

关键词： Vapor liquid equilibria Reactive distillation Activity coefficient 1,3,5-Trioxane production UNIFAC Salt effect