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Exploring the mechanical behavior and microstructure of compacted loess subjected to dry-wet cycles and chemical contamination

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第9期16卷 3673-3695页

作者： Yongpeng Nie Wankui Ni xiangfei lü Wenxin Tuo College of Geological Engineering and Geomatics Chang'an UniversityXi'an710054China Department of Civil Engineering Nagoya Institute of TechnologyNagoya466-8555Japan School of Water and Environment Chang'an UniversityXi'an710054China

Due to climatic factors and rapid urbanization,the soil in the loess Plateau,China,experiences the coupled effects of dry-wet cycles and chemical *** the mechanical behavior and corresponding microstructural evolution of contaminated loess subjected to dry-wet cycles is essential to elucidate the soil degradation ***,direct shear and consolidation tests were performed to investigate the variations in mechanical properties of compacted loess contaminated with acetic acid,sodium hydroxide,and sodium sulfate during dry-wet *** mechanical response mechanisms were investigated using zeta potential,mineral chemical composition,and scanning electron microscopy(SEM)*** results indicate that the mechanical deterioration of sodium hydroxidecontaminated loess during dry-wet cycles decreases with increasing contaminant concentration,which is mainly attributed to the thickening of the electrical double layer(EDl)by Nat and the precipitation of calcite,as well as the formation of colloidal flocs induced by OH,thus inhibiting the development of large pores during the dry-wet *** contrast,the attenuation of mechanical properties of both acetic acid-and sodium sulfate-contaminated loess becomes more severe with increasing contaminant concentration,with the latter being more particularly *** is primarily due to the reduction of the EDl thickness and the erosion of cement in the acidic environment,which facilitates the connectivity of pores during dry-wet ***,the salt expansion generated by the drying process of saline loess further intensifies the structural ***,the mechanical performance of compacted loess is sensitive to both pollutant type and concentration,exhibiting different response patterns in the dry-wet cycling condition.

关键词： Contaminated loess Dry-wet cycles Compressibility Shear strength Microstructural evolution

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金属卟啉基多孔聚合物催化环状碳酸酯制备反应的研究进展

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应用化工 2024年第7期53卷 1668-1671页

作者：李洁滢吕向菲周春雨孙道磊安文强王霞邵帅陆毕帅长安大学水利与环境学院陕西西安710054 长安大学旱区地下水文与生态效应教育部重点实验室陕西西安710054 长安大学水利部旱区生态水文与水安全重点实验室陕西西安710054 聊城市水文中心山东聊城252000

通过整理金属卟啉聚合物催化环氧烷烃与CO_(2)的制备环状碳酸酯相关文献,发现具有高比表面积的金属卟啉基多孔聚合物、卟啉环中心金属及小分子聚合单体中的亲核离子是温和条件下高效催化该反应的主要原因,目前合成的金属卟啉聚合物存在... 详细信息

通过整理金属卟啉聚合物催化环氧烷烃与CO_(2)的制备环状碳酸酯相关文献,发现具有高比表面积的金属卟啉基多孔聚合物、卟啉环中心金属及小分子聚合单体中的亲核离子是温和条件下高效催化该反应的主要原因,目前合成的金属卟啉聚合物存在孔道易变小、结构不稳定、难以适应大尺寸的环氧化物等问题,如何设计制备空间位阻小、性能稳定、拥有大量lewis酸碱高活性中心的双活性位点金属卟啉基多孔聚合物是未来此类催化剂的主要发展方向。

关键词：卟啉聚合物催化二氧化碳环状碳酸酯

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Engineered plant extracellular vesicles for autoimmune diseases therapy

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Nano Research 2024年第4期17卷 2857-2873页

作者： Ruina Han Yan Wu Yafei Han xiangfei liu Han liu Jiacan Su Institute of Translational Medicine Shanghai UniversityShanghai 200444China Organoid Research Center Shanghai UniversityShanghai 200444China National Center for Translational Medicine(Shanghai)SHU Branch Shanghai UniversityShanghai 200444China Department of Orthopedics Shanghai Zhongye HospitalShanghai 200941China Department of Orthopedics Xinhua HospitalShanghai Jiao Tong University School of MedicineShanghai 200092China

Autoimmune diseases(AID)encompass a diverse array of conditions characterized by immune system dysregulation,resulting in aberrant responses of B cells and T cells against the body’s own healthy *** extracellular vesicles(PEVs)are nanoscale particles enclosed by phospholipid bilayers,secreted by plant cells,which facilitate intercellular communication by transporting various bioactive *** to their nanoscale structure,safety,abundant sources,low immunogenicity,high yield,biocompatibility,and effective targeting of the colon and liver,PEVs are regarded as a promising platform for the treatment of *** review provides a comprehensive summary of PEV biogenesis,physicochemical and biological properties,internalization mechanisms,isolation methods,and their applications in various diseases,with a specific focus on their potential roles in ***,we propose engineering approaches and administration methods for ***,we present an overview of the advantages and challenges associated with utilizing PEVs for the treatment of *** gaining a comprehensive understanding of PEVs,we anticipate the development of innovative therapeutic strategies for *** and engineered PEVs hold substantial promise as a valuable resource for innovative technologies in AID treatment.

关键词： autoimmune diseases plant extracellular vesicles extracellular vesicles engineering modification

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Kinematic-mapping-model-guided analysis and optimization of 2-PSS&1-RR circular-rail parallel mechanism for fully steerable phased array antennas

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Defence Technology 2024年第8期38卷 136-154页

作者： Guodong Tan xiangfei Meng Xuechao Duan lulu Cheng Dingchao Niu Shuai He Dan Zhang laboratory of Electromechanical Coupling in Electronic Equipment Xidian University Department of Mechanical Engineering The Hong Kong Polytechnic University

This paper presents a systematic methodology for analyzing and optimizing an innovative antenna mount designed for phased array antennas, implemented through a novel 2-PSS&1-RR circular-rail parallel mechanism. Initially, a comparative motion analysis between the 3D model of the mount and its full-scale prototype is conducted to validate effectiveness. Given the inherent complexity, a kinematic mapping model is established between the mount and the crank-slider linkage, providing a guiding framework for subsequent analysis and optimization. Guided by this model, feasible inverse and forward solutions are derived, enabling precise identification of stiffness singularities. The concept of singularity distance is thus introduced to reflect the structural stiffness of the mount. Subsequently, also guided by the mapping model, a heuristic algorithm incorporating two backtracking procedures is developed to reduce the mount's mass. Additionally, a parametric finite-element model is employed to explore the relation between singularity distance and structural stiffness. The results indicate a significant reduction(about 16%) in the antenna mount's mass through the developed algorithm, while highlighting the singularity distance as an effective stiffness indicator for this type of antenna mount.

关键词： Backtracking Circular rail Crank-slider linkage Innovative antenna mount Kinematic mapping model Stiffness singularity

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Experimental demonstration of a photonic spiking neuron based on a DFB laser subject to side-mode optical pulse injection

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Science China(Information Sciences) 2024年第3期67卷 271-280页

作者： Shuiying XIANG Shuang GAO Yuechun SHI Yuna ZHANG Ziwei SONG Xingxing GUO Yahui ZHANG Yuxin MA xiangfei CHEN State Key laboratory of Integrated Service Networks Xidian University Yongjiang laboratory 3. College of Engineering and Applied Sciences Nanjing University

We proposed and experimentally demonstrated a simple and novel photonic spiking neuron based on a distributed feedback(DFB) laser subject to side-mode optical pulse injection(SMOPI). The DFB laser chip is designed and fabricated based on asymmetric equivalent π phase shift(π-EPS) with the reconstruction-equivalent-chirp(REC) technique. Under side-mode continuous-wave(CW) optical injection,excitability pulse was experimentally observed during the dominant mode switching process due to the injection-locked effect. Based on the transition between the excitability regime and the side-mode injection locking effect, the controllable and repeatable neuron-like spiking response can be realized when external stimulus pulses are electro-optically modulated on the CW optical carrier. The experimental results show that the spike threshold, temporal integration, and refractory period, which are important spike processing mechanisms in biological neurons, can all be achieved in the optically-injected DFB laser. The experimental findings are also verified numerically with a rate equation model that considers the SMOPI. To the best of our knowledge, this is the first experimental demonstration of a photonic spiking neuron based on a DFB laser subject to SMOPI, which holds promise for realizing large-scale photonic spiking neuron arrays for hardware photonic spiking neural network chips.

关键词： neuromorphic photonics photonic spiking neuron DFB laser side-mode optical pulse injections

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Experimental evaluation of factors affecting performance of concentrating photovoltaic/thermal system integrated with phase‐change materials(PV/T‐CPCM)

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Energy Storage and Saving 2024年第1期3卷 30-41页

作者： Zhaoyang luan lanlan Zhang xiangfei Kong Han li Man Fan School of Energy and Environmental Engineering Hebei University of TechnologyTianjin300401China School of Mechanical Engineering Beijing Institute of TechnologyBeijing100081China

The photovoltaic/thermal(PV/T)system is a promising option for countering energy *** improve the performance of PV/T systems,compound parabolic concentrators(CPCs)and phase-change materials(PCMs)were jointly applied to construct a concentrating photovoltaic/thermal system integrated with phase-change materials(PV/T-CPCM).An open-air environment is used to analyze the effects of different parameters and the intermittent operation strategy on the system *** results indicate that the short-circuit current and open-circuit voltage are positively correlated with the solar irradiance,but the open-circuit voltage is negatively correlated with the temperature of the PV *** the solar irradiance is 500 W⋅m^(−2) and the temperature of the PV modules is 27.5℃,the short-circuit current and open-circuit voltage are 1.0 A and 44.5 V,*** solar irradiance results in higher thermal power,whereas the thermal efficiency is under lower solar irradiance(136.2-167.1 W⋅m^(−2) is twice under higher solar irradiance(272.3-455.7 W⋅m^(−2))).In addition,a higher mass flow rate corresponds to a better cooling effect and greater pump energy *** the mass flow rate increases from 0.01 to 0.02 kg⋅s^(-1),the temperature difference between the inlet and outlet decreases by 1.8℃,and the primary energy-saving efficiency decreases by 0.53%.The intermittent operation of a water pump can reduce the energy consumption of the system,and the combination of liquid cooling with PCMs provides better thermal regulation and energy-saving effects under various conditions.

关键词： Compound parabolic concentrator Factor analysis Open-air experiment Phase-change materials Photovoltaic/thermal system

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基于虚拟零部件的零等待约束复杂产品综合调度算法

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机械工程学报 2020年第4期56卷 246-257页

作者：郭伟飞雷琦宋豫川吕向飞李磊重庆大学机械传动国家重点实验室重庆400030

针对复杂产品实际生产中工序间存在零等待约束的综合调度问题,提出一种基于设计结构矩阵和遗传算法的综合调度算法。该算法在提出零等待虚拟零部件、非零等待虚拟零部件、叉点虚拟零部件以及子虚拟零部件等概念的基础上,设计一种更为有... 详细信息

针对复杂产品实际生产中工序间存在零等待约束的综合调度问题,提出一种基于设计结构矩阵和遗传算法的综合调度算法。该算法在提出零等待虚拟零部件、非零等待虚拟零部件、叉点虚拟零部件以及子虚拟零部件等概念的基础上,设计一种更为有效的基于数字化虚拟零部件下三角设计结构矩阵的编码方式,不仅满足了复杂产品的加工装配顺序约束关系,而且体现了工序间存在的零等待约束;设计了能满足加工装配顺序约束的遗传算子,避免了不可行子代个体转化操作;提出一种满足零等待约束的解码方法,且能确保染色体经过解码后能够产生主动调度。与现有算法进行对比试验,结果表明所提出的调度算法对于存在零等待约束的复杂产品综合调度问题具有良好的求解速度和质量。

关键词：零等待约束虚拟零部件遗传算法综合调度

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bcc结构下二元合金Fe-X(X=Cr,Co,Mo,W)低温低浓度下固溶软化行为的机制

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高等学校化学学报 2024年第6期45卷 15-21页

作者：王娜李翔飞北京科技大学冶金与生态工程学院北京100083

采用第一性原理计算研究了体心立方(bcc)Fe的4种二元合金Fe-X(X=Cr,Co,Mo,W)低温低浓度下固溶软化行为的机制,发现低温低浓度下的固溶软化行为由双扭结形核控制,由溶质原子直接引起双扭结形核势垒降低为固溶软化的本征机制,而由溶质原... 详细信息

采用第一性原理计算研究了体心立方(bcc)Fe的4种二元合金Fe-X(X=Cr,Co,Mo,W)低温低浓度下固溶软化行为的机制,发现低温低浓度下的固溶软化行为由双扭结形核控制,由溶质原子直接引起双扭结形核势垒降低为固溶软化的本征机制,而由溶质原子对间隙原子清除减少双扭结形核为固溶软化的外部机制.分别计算了bcc Fe的4种二元合金Fe-X(X=Cr,Co,Mo,W)中反映双扭结形核势垒的原子行位移(ARD)能和堆垛层错(GSF)能.计算结果表明,仅Cr可微弱降低ARD和GSF能,而Co,Mo,W均引起ARD和GSF能升高,因此,依据固溶软化的本征机制,仅Cr引起固溶软化,而Co,Mo,W均引起固溶强化.Cr,Mo,W与周围Fe原子均为反铁磁相互作用,Co与Fe为铁磁相互作用.尽管铁磁/反铁磁相互作用与价电子数(电子构型)具有一定相关性,双扭结形核势垒并不与价电子数(电子构型)明显相关.进一步的计算表明,双扭结形核势垒与其结合能呈现正相关关系,Cr与Fe结合能减弱,因此双扭结形核势垒降低,而Co,Mo,W与Fe结合能增强,因此双扭结形核势垒升高.而结合能并未表现出与原子半径、电子数(电子构型)的明显相关性,因此,双扭结形核势垒并不与原子半径、电子数(电子构型)明显相关.依据本征机制,Co,Mo,W与Fe的结合能增强引起双扭结形核势垒升高,因此为固溶强化,其二元合金低温低浓度下的固溶软化行为无法用本征机制解释,需要考虑外部机制(如间隙C原子的作用),而Cr二元合金的固溶软化行为可能为本征机制.

关键词：体心立方铁二元合金原子行位移能堆垛层错能固溶软化

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Hybrid-integrated 200 Gb/s REC-DMl array transmitter based on photonic wire bonding technology

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CHINESE OPTICS lETTERS 2024年第8期22卷 081401-081401页

作者： Ma, Yuxin Zhao, Jie Yang, Tongtong Mei, Yipeng Sun, Zhenxing lu, Jun li, Shaobo Ma, Xiang Chen, xiangfei Nanjing Univ Key Lab Intelligent Opt Sensing & Manipulat Minist Educ Nanjing 210023 Peoples R China Nanjing Univ Natl Lab Solid State Microstruct Nanjing 210023 Peoples R China Nanjing Univ Coll Engn & Appl Sci Nanjing 210023 Peoples R China Nanjing Univ Inst Opt Commun Engn Nanjing 210023 Peoples R China Nanjing Univ Nanjing Univ Tongding Joint Lab Large Scale Photon Nanjing 210023 Peoples R China China Elect Technol Grp Corp Res Inst 54 Opt Commun Res & Dev Ctr Shijiazhuang 050081 Peoples R China

An 8-channel hybrid-integrated chip for 200 Gb/s (8 x 25 Gb/s) signal transmission has been demonstrated. The channels are all within the O-band, and with a spacing of 800 GHz. The core of this chip is a monolithic integrated multi-wavelength laser array of 8 directly-modulated distributed feedback (DFB) lasers. By using the reconstruction equivalent chirp technique, multi-wavelength integration and asymmetric phase shift structures are achieved in the laser array. The output laser beams of the array are combined by a planar light-wave circuit, which is hybrid-integrated with the laser array by photonic wire bonding. Experiment results of this transmitter chip show good single-mode working of each unit laser, with a side- mode suppression ratio above 50 dB, and the modulation bandwidth is above 20 GHz. Clear eye diagrams are obtained in the lasers for 25 Gb/s non-return-to-zero modulation, which implies a total 200 Gb/s transmission rate for the whole chip.

关键词： direct modulation laser array reconstruction equivalent chirp photonic wire bonding hybrid integration lASER ARRAY SEMICONDUCTOR-lASER

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Making waste profitable: Efficient recovery of metallic iron from jarosite residues

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Chinese Journal of Chemical Engineering 2024年第7期71卷 66-76页

作者： Songshan Zhou Yunhui Han Rong Huang Yin Huang Qingyuan Dong Haiyin Gang Jinchuan Qin Xi Yu xiangfei Zeng Wenxing Cao Jiqin Wang Shaoqin Chen Rong Wang Mengjun Chen Key laboratory of Solid Waste Treatment and Resource Recycle(SWUST) Ministry of EducationSouthwest University of Science and TechnologyMianyang 621010China School of Environment Key Laboratory of Yellow River and Huai River Water Environment and Pollution ControlMinistry of EducationHenan Normal UniversityXinxiang 453007China School of National Defense Science and Technology College SWUST Ministry of EducationSouthwest University of Science and TechnologyMianyang 621010China

To address the hazardous by-product of zinc smelting and resource utilization of jarosite residue,this study applies an electric field-assisted hot acid treatment to completely recycle iron(Fe).This innovative approach aims to enhance the leaching efficiency of Fe from jarosite *** introduction of an electric field changes the charge distribution on the surface of the particles to enhance ions and electrons exchange and promotes the collision between particles to strengthen reaction *** on the above,the leaching efficiency of Fe in jarosite under sulfuric acid attack has improved *** result shows that Fe leaching efficiency reaches 98.83%,which is increased by 28%under the optimal experimental conditions:current density of 30 mA·cm^(-2),H_(2)SO_(4) concentration of 1.5 mol·l^(-1),solid-liquid ratio of 70 g·l^(-1),temperature of 80℃ and time of 12 *** kinetics calculations show that the apparent activation energy is 16.97 kJ·mol^(-1) and the leaching of jarosite residue is controlled by a mixture of chemical reaction and diffusion,as well as the temperature and concentration of the leaching solution have an influence on *** work provides a feasible idea for the efficient leaching of Fe from jarosite residue.

关键词： Jarosite residue Electric filed leaching kinetics

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