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An approximate analytical solution to the ultrafiltration profile in a hemodialysis process between parallel porous plates

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Chinese Science Bulletin 2008年第21期53卷 3402-3408页

作者： lu JunFeng LU Wenqiang Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100080 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

In a hemodialysis process,the blood that runs through straight channels exchanges substances with the dialysate through a semi-permeable membrane.The waste products,such as urea and creatinine,are therefore removed from the plasma by the membrane.In the analysis of this process,determination of the ultra-filtration profile along the porous membrane surface remains a difficult problem.In this work,an analytical solution to the derivation of such a profile was detailed,and the feasibility of this solution was discussed.The ultra-filtration profile was found to be in a cosine shape.

关键词：过滤分析近似值多孔板块血液透析

Study on Laminar Natural Convection Heat Transfer from a Hemisphere with Uniform Heat Flux Surface

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Journal of Thermal Science 2019年第2期28卷 232-245页

作者： ZHANG Jian LIU Jie LU Wenqiang School of Engineering Science University of Chinese Academy of Sciences

By employing the modified model based on Bejan et al., laminar natural convection heat transfer from a hemisphere with uniform heat flux surface has been numerically investigated. Extensive results of two different surface boundary conditions are obtained for a wide range of Grashof numbers(10 ≤ Gr ≤ 10~7) and Prandlt number of 0.72. The characteristics of heat transfer and fluid flow are analyzed in terms of isotherm contours and streamline patterns, radial and tangential velocities, dimensionless temperature profiles, local friction and pressure drag coefficients, as well as local and average Nusselt numbers. Meanwhile, the effects of Grashof number and adiabatic surface on flow motion and heat transfer have been studied. No recirculation zone or flow separation generates over the top of the hemisphere compared to the isothermal sphere. Owing to the curvature effect, the maximum values of local friction and pressure drag coefficients appear at the corner point B. Comparisons with the previous results are also reported in detail. All the results are in good agreement with the numerical data. Moreover, both local and average Nusselt numbers show a positive dependence on Grashof number. The values of the non-adiabatic case are smaller than that of the adiabatic case due to the preheating effect. Finally, two precise and general correlations of average Nusselt number varying with Grashof numbers have been presented, which can provide an effective prediction for the heat transfer rate in engineering applications, and offer academic values for the future research.

关键词： numerical simulation natural convection hemisphere uniform heat flux heat transfer correlations

Cobalt phosphide nanoparticles supported within network of N-doped carbon nanotubes as a multifunctional and scalable electrocatalyst for water splitting

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Journal of Energy Chemistry 2021年第1期30卷 130-138,I0005页

作者： Dongxu Yang wenqiang Hou Yingjiong lu Wanli Zhang Yuanfu Chen School of Electronic Science and Engineering and State Key Laboratory of Electronic Thin Films and Integrated DevicesUniversity of Electronic Science and Technology of ChinaChengdu 610054SichuanChina Department of Physics School of Scienceand Everest Research InstituteTibet UniversityLhasa 850000Xizang(Tibet)Autonomous RegionChina School of Electronic Science and Engineering Xi’an Jiaotong UniversityXi’an 710049ShaanxiChina

In order to realize industrial production of hydrogen through water splitting,it is essential to develop a cost-efficient and scalable approach to synthesize nonprecious electrocatalysts with sufficiently high activity and stability to replace commercial noble-metal-based electrocatalysts.Herein we synthesize cobalt phosphide nanoparticles dispersed within nitrogen-doped carbon nanotube network(CP@NCNT) via scalable spray drying and thermal treatments.As a multifunctional electrocatalyst,the CP@NCNT hybrid delivers outstanding activity for HER(in both acidic and alkaline electrolytes),OER and overall water splitting.Remarkably,it shows an ultra-low overpotental of 94 mV to obtain 10 mA cm-2 in HER.It also demonstrates outstanding activity in overall water splitting,requiring only 1.619 V to deliver 10 mA cm-2with more than 72 h’ long-term stability.The combination of notable performance,multi-functionality and highly scalable spray-drying synthesis method enables this material as a novel and cost-efficient transition metal-based electrocatalysts for overall water splitting.

关键词： Obalt phosphides Carbon nanotube Nitrogen doping Large-scale synthesis Overall water splitting

Development Holds the Key to Addressing All Chinas Problems

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Qiu Shi 2013年第3期5卷 56-60页

作者： LU Wenqiang

Theoretical Analysis and Reflections on the ＂Middle-Income Trap＂

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Qiu Shi 2012年第1期4卷 59-66页

作者： LU Wenqiang

Decorating MXene with tiny ZIF-8 nanoparticles:An effective approach to construct composites for water pollutant removal

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Chinese Journal of Chemical Engineering 2022年第2期35卷 42-48页

作者： Chen Gu wenqiang Weng Cong lu Peng Tan Yao Jiang Qiang Zhang Xiaoqin Liu Linbing Sun State Key Laboratory of Materials-Oriented Chemical Engineering Jiangsu National Synergetic Innovation Center for Advanced Material(SICAM)College of Chemical EngineeringNanjing Tech UniversityNanjing 211816China Department of Chemistry Washington State UniversityPullmanWashington 99163United States

MXenes have attracted increasing research enthusiasm owing to their unique physical and chemical properties.Although MXenes exhibit exciting potential in cations adsorption due to their unique surface groups,the adsorption capacity is limited by the low specific surface area and undeveloped porosity.Our work aims at enhancing the adsorption performance of a well-known MXene,Ti3C2Tx,for methylene blue(MB)by decorating tiny ZIF-8 nanoparticles in the interlayer.After the incorporation of ZIF-8,suitable interspace in the layers resulting from the distribution of tiny ZIF-8 appears.When employing in MB,the adsorption capacity of composites can reach up to 107 mg·g^(-1) while both ZIF-8(3 mg·g^(-1))and Ti_(3)C_(2)Tx(9mg·g^(-1))show nearly no adsorption capacity.The adsorption mechanism was explored,and the good adsorption capacity is caused by the synergistic effect of ZIF-8 and Ti_(3)C_(2)Tx,for neither of them is of suitable interspace or surface groups for MB adsorption.Our work might pave the way for constructing functional materials based on the introduction of nanoparticles into layered materials for various adsorption applications.

关键词： Ti3C2Tx MXene MOF nanoparticles Adsorption Composites

Tailoring mechanical properties of PμSL 3D-printed structures via size effect

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International Journal of Extreme Manufacturing 2022年第4期4卷 261-268页

作者： wenqiang Zhang Haitao Ye Xiaobin Feng Wenzhao Zhou Ke Cao Maoyuan Li Sufeng Fan Yang lu Department of Mechanical Engineering City University of Hong KongKowloonHong Kong SAR 999077People's Republic of China Nano-Manufacturing Laboratory(NML) City University of Hong Kong Shenzhen Research InstituteShenzhen 518057People's Republic of China Department of Mechanical and Energy Engineering Southern University of Science and TechnologyShenzhen 518055People's Republic of China Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics Wuhan University of TechnologyWuhan 430070People's Republic of China School of Mechano-Electronic Engineering Xidian UniversityXi'an 710071People's Republic of China State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074People's Republic of China School of Mechanics and Safety Engineering Zhengzhou UniversityZhengzhou 450001People's Republic of China

Projection micro stereolithography(PμSL)has emerged as a powerful three-dimensional(3D)printing technique for manufacturing polymer structures with micron-scale high resolution at high printing speed,which enables the production of customized 3D microlattices with feature sizes down to several microns.However,the mechanical properties of as-printed polymers were not systemically studied at the relevant length scales,especially when the feature sizes step into micron/sub-micron level,limiting its reliable performance prediction in micro/nanolattice and other metamaterial applications.In this work,we demonstrate that PμSL-printed microfibers could become stronger and significantly more ductile with reduced size ranging from 20μm to 60μm,showing an obvious size-dependent mechanical behavior,in which the size decreases to 20μm with a fracture strain up to~100%and fracture strength up to~100 MPa.Such size effect enables the tailoring of the material strength and stiffness of PμSL-printed microlattices over a broad range,allowing to fabricate the microlattice metamaterials with desired/tunable mechanical properties for various structural and functional applications.

关键词： 3D printing projection micro-stereolithography(PμSL) size effect microfiber mechanical properties microlattice metamaterial

Sustainable silicon anodes facilitated via a double-layer interface engineering: Inner SiOx combined with outer nitrogen and boron co-doped carbon

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Carbon Energy 2022年第3期4卷 399-410页

作者： Jun Zhou Yao lu Lishan Yang wenqiang Zhu Weifang Liu Yahui Yang Kaiyu Liu Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research(Ministry of Education) National and Local Joint Engineering Laboratory for New Petrochemical Materials and Fine Utilization of ResourcesKey Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan ProvinceHunan Normal UniversityChangshaHunanP.R.China College of Chemistry and Chemical Engineering Central South UniversityChangshaHunanP.R.China

Silicon-based(Si)materials are promising anodes for lithium-ion batteries(LIBs)because of their ultrahigh theoretical capacity of 4200 mA h g^(−1).However,commercial applications of Si anodes have been hindered by their drastic volume variation(∼300%)and low electrical conductivity.Here,to tackle the drawbacks,a hierarchical Si anode with double-layer coatings of a SiOx inner layer and a nitrogen(N),boron(B)co-doped carbon(C-NB)outer layer is elaborately designed by copyrolysis of Si-OH structures and a H3BO_(3)-doped polyaniline polymer on the Si surface.Compared with the pristine Si anodes(7mA h g^(−1) at 0.5 A g^(−1) after 340 cycles and 340 mA h g^(−1) at 5 A g^(−1)),the modified Si-based materials(Si@SiOx@C-NB nanospheres)present su perior cycling stability(reversible 1301 mA h g^(−1) at 0.5 A g^(−1) after 340 cycles)as well as excellent rate capability(690mA h g^(−1) at 5 A g^(−1))when used as anodes in LIBs.The unique double-layer coating structure,in which the inner amorphous SiOx layer acts as a buffer matrix and the outer defect-rich carbon enhances the electron diffusion of the whole anode,makes it possible to de liver excellent electrochemical properties.These results indicate that our double-layer coating strategy is a promising approach not only for the devel opment of sustainable Si anodes but also for the design of multielement-doped carbon nanomaterials.

关键词： boron-nitrogen co-doped carbon coating silicon anode stability wettability

基于改进YOLOv4-tiny算法的手势识别

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电子与信息学报 2021年第11期43卷 3257-3265页

作者：卢迪马文强哈尔滨理工大学哈尔滨150080

随着人机交互的发展,手势识别越来越重要。同时,移动端应用发展迅速,将人机交互技术在移动端实现是一个发展趋势。该文提出一种改进YOLOv4-tiny的手势识别算法。首先,在YOLOv4-tiny网络基础上,添加空间金字塔池化(SPP)模块,融合了图像... 详细信息

随着人机交互的发展,手势识别越来越重要。同时,移动端应用发展迅速,将人机交互技术在移动端实现是一个发展趋势。该文提出一种改进YOLOv4-tiny的手势识别算法。首先,在YOLOv4-tiny网络基础上,添加空间金字塔池化(SPP)模块,融合了图像的局部和全局特征,增强网络的准确定位能力。其次,在YOLOv4-tiny原网络的3个最大池化层和新增SPP模块后各添加一个1×1的卷积模块,减少了网络的参数,提高网络的预测速度。在此基础上,利用K-means++算法生成适合检测手势的先验框,加快网络检测手势。在手势数据集NUSII上,与YOLOv3-tiny算法和YOLOv4-tiny算法进行对比,改进算法平均精度均值(mAP)为100%,每秒传输帧数(fps)为377,可以快速准确地检测识别手势。将该文改进算法部署在安卓(Android)移动端,实现了移动端实时的手势检测与识别,对人机交互的发展有很大的研究意义。

关键词：手势识别人机交互 YOLOv4-tiny 安卓