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纳米或超细WC-Co粉体制备过程强化研究进展

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中国粉体技术 2025年第1期31卷 1-10页

作者：潘锋尚慧俊黎亨利杜占中国科学院过程工程研究所介科学与工程全国重点实验室北京100190 北京工业大学材料科学与工程学院北京100124 石河子大学化学化工学院新疆石河子832003 中铝环保节能集团有限公司河北雄安050004

【目的】总结纳米或超细碳化钨钴(WC-Co)粉体制备过程的研究,解决WC-Co做为热喷涂原料对机械零件的磨损和腐蚀的影响。【研究现状】总结纳米或超细WC-Co制备过程强化、反应路径,以及Co对还原碳化过程的作用等;其中机械作用力强化包括球... 详细信息

【目的】总结纳米或超细碳化钨钴(WC-Co)粉体制备过程的研究,解决WC-Co做为热喷涂原料对机械零件的磨损和腐蚀的影响。【研究现状】总结纳米或超细WC-Co制备过程强化、反应路径,以及Co对还原碳化过程的作用等;其中机械作用力强化包括球磨强度的影响、氧化钨原料的影响、反应温度的影响,原子或分子水平强化包括气相化学合成、喷雾转化,气相碳质强化反应过程包括烃类物质、一氧化碳;纳米或超细WC-Co制备过程反应路径包括还原过程、碳化过程;对还原碳化过程的作用包括Co对氧化钨还原碳化过程具有催化作用、Co影响WC-Co产物粒径、Co含量增加降低碳化温度、Co促进气态碳源析碳等。【结论与展望】提出WC-Co粉体制备反应路径方面,应深入揭示制备反应路径,应进一步分析缺碳相η物相在制备过程中的作用,对W、Co、C扩散的影响机制;认为模拟分析反应过程中还原碳化气与固体原料之间的热量、质量传递过程,可为制备过程进一步优化调控和反应器放大设计奠定理论基础;同时WC-Co粉体热喷涂性能方面,用于机械件的喷涂处理时,应测试涂层的抗磨损和腐蚀性能,反馈调控优化和制备过程。

关键词：硬质合金涂层纳米或超细WC-Co 技术进展反应路径

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粗粒土力学特性大型平面应变试验研究

长江科学院院报 2025年第1期42卷 129-135,143页

作者：姜景山左永振程展林黄鑫张超王志华南京工程学院建筑工程学院南京211167 长江科学院水利部岩土力学与工程重点实验室武汉430010 河海大学岩土工程科学研究所南京210098 南京吉欧地下空间科技有限公司南京211816

土石坝填料一般处于平面应变状态,目前填料力学特性研究基本采用大型三轴试验。由于三轴应力状态下中主应力等于小主应力,平面应变状态下大坝填料的力学性能会被低估。为充分认识填料潜能,科学设计和合理评估土石坝,有必要对填料开展平... 详细信息

土石坝填料一般处于平面应变状态,目前填料力学特性研究基本采用大型三轴试验。由于三轴应力状态下中主应力等于小主应力,平面应变状态下大坝填料的力学性能会被低估。为充分认识填料潜能,科学设计和合理评估土石坝,有必要对填料开展平面应变试验研究。应用大型真三轴仪对填料进行了大型平面应变试验,共开展了4种不同初始干密度的粗粒土平面应变各向等压固结排水剪切试验。结果表明:应力-应变关系主要为应变硬化型,应力曲线呈爬升型,体变表现为剪缩。某一小主应力下,大小主应力之差的最大值随初始干密度的增大呈线性增大;初始干密度一定时,大小主应力之差的最大值与小主应力呈线性关系增大。初始剪切阶段,小主应力一定时,偏应力与球应力之比曲线斜率随初始干密度的增大而增大,随剪切变形的发展,不同初始干密度的应力比曲线逐渐趋于接近。偏应力随球应力的增大单调增加则对应应变硬化型,若偏应力随球应力的增大先增加后减小则对应应变软化型。相同小主应力时,初始弹性模量随初始干密度的增大而增大,近似呈线性关系;某一初始干密度下,初始弹性模量随小主应力的增大基本呈线性关系增大。中主应力系数随大主应力方向应变的增大而增大,曲线形态呈三折线形,初始剪切阶段增长较为缓慢,随剪切变形的增大增长相对加快并呈线性关系增大,如曲线末端下弯为应变硬化型,曲线末端上翘为应变软化型。

关键词：粗粒土大型平面应变试验力学特性主应力偏应力球应力大型真三轴仪

Quantum Effects of Mesoscopic Inductance and Capacity Coupling Circuits

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Communications in Theoretical Physics 2006年第6期45卷 1126-1130页

作者： LIU Jian-Xin AN zhan-Yuan SONG yong-Hua Department of Electrical Engineering North China Electric Power University Baoding 071003 China Department of Applied Physics North China Electric Power University Baoding 071003 China Electronic and Computer Engineering Department Brunel University London UK

Using the quantum theory for a mesoscopic circuit based on the discretenes of electric charges, the finitedifference Schrodinger equation of the non-dlssipative mesoscopic inductance and capacity coupling circuit is achieved. The Coulomb blockade effect, which is caused by the discreteness of electric charges, is studied. Appropriately choose the components in the circuits, the finlte-dlfference Schrodinger equation can be divided into two Mathieu equations in representation.＂ With the WKBJ method, the currents quantum fluctuations in the ground states of the two circuits are calculated. The results show that the currents quantum zero-point fluctuations of the two circuits are exist and correlated.

关键词： mesoscopic circuit Mathieu equation quantum effect

Optimal configuration for vibration frequencies in a ring of harmonic oscillators： The nonidentical mass effect

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Frontiers of physics 2015年第3期10卷 89-100页

作者： Shuai Liu Guo-yong zhang Zhiwei He Meng zhan College of Science Northwest A&F University Yangling 712100 China Wuhan Center for Magnetic Resonance State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences Wuhan 430071 China College of Computer Science and Technology Hubei Normal University Huangshi 435002 China University of the Chinese Academy of Sciences Beijing 100049 China

The parameter diversity effect in coupled nonidentical elements has attracted persistent interest in nonlinear dynamics. Of fundamental importance is the so-called optimal configuration problem for how the spatial position of elements with different parameters precisely determines the dynamics of the whole system. In this work, we study the optimal configuration problem for the vibration spectra in the classical mass-spring model with a ring configuration, paying particular attention to how the configuration of different masses affects the second smallest vibration frequency （ω2） and the largest one （ωN）. For the extreme values of ω2 and ωN, namely, （ω2）min, （ω2）max, （ωN）min, and （ωN）max, we find some explicit organization rules for the optimal configurations and some approximation rules when the explicit organization rules are not available. The different distributions of ω2 and ωN are compared. These findings are interesting and valuable for uncovering the underlying mechanism of the parameter diversity effect in more general cases.

关键词： synchronization vibration frequencies normal modes complex systems

Design method of pile-slab structure roadbed of ballastless track on soil subgrade

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Journal of Central South University 2013年第7期20卷 2072-2082页

作者： zhan yong-xiang YAO Hai-lin JIANG Guan-lu Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan 430071 China State Key Laboratory of Geomechanics and Geotechnical Engineering (Institute of Rock and soil Mechanics Chinese Academy of Sciences) Wuhan 430071 China School of Civil Engineering Southwest Jiaotong University Chengdu 610031 China

Pile-slab structure roadbed is a new form of ballastless track for high speed railway. Due to lack of corresponding design code, based on the analysis of its structure characteristics and application requirements, it is proposed to carry out load effect combination according to ultimate limit state and serviceability limit state, and the most unfavorable combination of each state is chosen to carry through design calculation for pile-slab structure. Space model of pile-slab structure can be simplified as a plane flame model, by using the orthogonal test method, and the design parameter of pile-slab structure is optimized. Moreover, based on the engineering background of Suining-Chongqing high-speed railway, the dynamic deformation characteristics of pile-slab structure roadbed are further researched by carrying on the indoor dynamic model test. The test results show that the settlement after construction of subgrade satisfies the requirement of settlement control to build ballastless track on soil subgrade for high-speed railway. Slab structure plays the role of arch shell as load is transmitted from slab to pile, and the vertical dynamic stress of subgrade soil is approximately of ＂K＂ form distribution with the depth. The distribution of pile stress is closely related to soil characteristics, which has an upset triangle shape where the large dynamic stress is at the top. Pile compared with soil shares most dynamic stress. Pile structure expands the depth of the dynamic response of subgrade has limited effect on dynamic response. These results can provide subgrade. and improves the stress of subgrade soil, and the speed of train scientific basis for pile-slab structure roadbed used on soil

关键词： soil subgrade ballastless track pile-slab structure roadbed load combination dynamic model test

THE WALL EFFECT ON VENTILATED CAVITATING FLOWS IN CLOSED CAVITATION TUNNELS

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Journal of Hydrodynamics 2008年第5期20卷 561-566页

作者： CHEN Xin LU Chuan-jing LI Jie pan zhan-cheng Department of Engineering Mechanics Shanghai Jiao Tong University Shanghai 200240 China

For ventilated cavitating flows in a closed water tunnel, the wall effect may exert an important influence on cavity shape and hydrodynamics, An isotropic mixture multiphase model was established to study the wall effect based on the RANS equations, coupled with a natural cavitation model and the RNG k-ε turbulent model. The governing equations were discretized using the finite volume method and solved by the Gauss-Seidel linear equation solver on the basis of a segregation algorithm. The algebraic multigrid approach was carried through to accelerate the convergence of solution. The steady ventilated cavitating flows in water tunnels of different diameter were simulated for a conceptual underwater vehicle model which had a disk cavitator. It is found that the choked cavitation number derived is close to the approximate solution of natural cavitating flow for a 3-D disk. The critical ventilation rate falls with decreasing diameter of the water tunnel. However, the cavity size and drag coeflicient are rising with the decrease in tunnel diameter for the same ventilation rate, and the cavity size will be much different in water tunnels of different diameter even for the same ventilated cavitation number.

关键词： ventilated cavitation water tunnel choked cavitation number critical ventilation rate

Redox-responsive polymer prodrug/AgNPs hybrid nanoparticles for drug delivery

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Chinese Chemical Letters 2018年第2期29卷 301-304页

作者： Liang Qiu Linfei Zhao Chengfen Xing yong zhan Institute of Biophysics Hebei University of Technology

A drug carrier system of the hybrid nanoparticles based on the redox-responsive P[（2-（（2-（（camptothecin）-oxy）ethyl）disulfanyl）ethylmethacrylate）-co-（2-（D-galactose）methylmethacryl-ate）]（P（MACPTS-co-MAGP）） and AgNPs is developed to deliver the anti-cancer drug camptothecin（CPT） and monitor the drug release by the recovery of the fluorescence of CPT. CPT is linked to the polymer sidechains via a redox-responsive disulfide bond, attaching on the surface of AgNPs and leading to the quenching of CPT fluorescence（＂off＂ state） due to the nanoparticle surface energy transfer（NSET） *** the exposure to glutathione（GSH）, the disulfide bond is cleaved to release CPT, resulting in the recovery of the fluorescence of CPT（＂on＂ state）. The system offers a platform to track the CPT delivery and releasing in real time

关键词： Redox-responsive Drug delivery system Hybrid nanoparticles NSET effect

Effective Potential of a Two-State Model for Molecular Motor

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Communications in Theoretical Physics 2005年第2期43卷 377-381页

作者： HANYing-Rong ZHAOTong-Jun zhan-yong YANWei-Li SchoolofScience HebeiUniversityofTechnologyTianjin300130China SchoolofScience HebeiUniversityofTechnologyTianjin300130China／／SchoolofElectricalEngineeringHebeiUniversityofTechnologyTianjin300130China SchoolofElectricalEngineering HebeiUniversityofTechnologyTianjin300130China

We study force generation and motion of molecular motors using a simple two-state model in the *** and periodic potential is adopted to describe the interaction between motor proteins and filaments that are periodic and polar. The current and the slope of the effective potential as functions of the temperature and transition rates are calculated in the two-state model. The ratio of the slope of the effective potential to the current is also calculated. It is shown that the directed motion of motor proteins is relevant to the effective potential. The slope of the effective potential corresponds to an average force. The non-vanishing force therefore implies that detailed balance is broken in the process of transition between different states.

关键词： Brownian particle directed motion Fokker-Planck equation effective potential detailed balance

The potential risks of C-C chemokine receptor 5-edited babies in bone development

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Bone Research 2019年第1期7卷 118-121页

作者： yong Xie Shaohua zhan Wei Ge Peifu Tang Department of Orthopedics Chinese PLA General HospitalBeijingChina State Key Laboratory of Medical Molecular Biology and Department of Immunology Institute of Basic Medical SciencesChinese Academy of Medical SciencesBeijingChina

Hutter et al.1 first reported that a bone marrow transplant using stem cells derived from a donor with homozygous CCR5 delta32 gene mutation remained HIV-positive but virus-free(below the limits of detection)after halting antiretroviral *** this observation in 2009,mutation of the CCR5 gene has become an important target in the prevention and treatment of HIV *** CRISPR-Cas9 system,which has been called the biggest biotech discovery in the history of molecular biology,can be used for precise genome engineering with the aim of treating genetic ***,the application of gene-editing tools,such as CRISPR-Cas9,for genetic engineering of embryos for use in assisted reproduction is prohibited in much of Europe,the United States,and China.2–3.

关键词： Hutter transplant cells