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Journal of Environmental Sciences 2024年第2期136卷 213-225页

作者： Bowen Xu Jiaxin Qu Xueqian Wang Langlang Wang Yu pu Ping Ning Yibing xie Yixing Ma Qiang Ma Faculty of Environmental Science and Engineering Kunming University of Science and TechnologyKunming 650500China School of Architecture and Civil Engineering Chengdu UniversityChengdu 610106China

To investigate the enhancing effect of Mn on the performance of simultaneous catalytic oxidation of AsH_(3)and PH_(3)by CuO-Al_(2)O_(3)in a reducing atmosphere under micro-oxygen conditions,Cu-Mn modifiedγ-Al_(2)O_(3)catalysts were prepared.The characteristics of the catalysts showed that Mn reduced the crystallinity of the active CuO component,increased the number of oxygen vacancies and acidic sites on the catalyst surface,enhanced the mobility of surface oxygen,and the interaction between copper and manganese promoted the redox cycling ability of the catalysts and improved their oxidation performance,which increased the conversion frequency(TOF)by 2.54×10^(-2)to 3.07×10^(-2)sec^(-1).On the other hand,the introduction of Mn reduced the production of phosphate and As_(2)O_(3)on the catalyst surface by30.96%and 44.9%,which reduced the coverage and inerting of the active sites by phosphate and As_(2)O_(3),resulting in an 8 hr(6 hr)improvement in the stability of PH_(3)(AsH_(3))removal.

关键词： AsH_(3)-PH_(3)removal Oxygen activation Mn doping Stability enhancement

Population size estimates based on GPS telemetry

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Zoological Research 2024年第1期45卷 36-38页

作者： Yu-Xuan Fan pu-Zheng xie Chi Ma Ting Chen Xiao Ye Hua-Lin Xu Qiong Yang Peng-Fei Fan School of Life Sciences Sun Yat-sen UniversityGuangzhouGuangdong 510275China College of Agriculture and Biological Sciences DaliYunnan 671003China Neilingding-Futian National Nature Reserve of Guangdong ShenzhenGuangdong 518040China

DEAR EDITOR,Accurate estimation of population size is a crucial issue in wildlife population ecology and conservation.While Global Positioning System(GPS)collars are well recognized as an effective method for monitoring wildlife behavior,their application in direct wildlife population size estimation remains underutilized.In this study,GPS telemetry was employed to survey a rhesus macaque(Macaca mulatta)population on Neilingding Island in Guangdong,China.From May 2021 to April 2022,32 macaques across nine groups were fitted with GPS collars,producing a dataset of 109739 location fixes.Analyzing data from all tracked individuals revealed the annual home ranges of the nine groups.

关键词： China Island size

Origin of the Disparity between the Stability of Transmutated Mix-Cation and Mix-Anion Compounds

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Chinese Physics Letters 2024年第5期41卷 53-60页

作者：野仕伟耿松源梁汉普张燮魏苏淮 Beijing Computational Science Research Center Beijing 100193China Advanced Materials Thrust Function HubHong Kong University of Science and TechnologyGuangzhou 511458China School of Materials Science and Engineering Northwestern Polytechnical UniversityXi’an 710072China

Transmutation is an efficient approach for material design. For example, ternary compound CuGaSe_(2) in chalcopyrite structure is a promising material for novel optoelectronic and thermoelectric device applications. It can be considered as formed from the binary host compound ZnSe in zinc-blende structure by cation transmutation(i.e., replacing two Zn atoms by one Cu and one Ga). While cation-transmutated materials are common, aniontransmutated ternary materials are rare, for example, Zn_(2)As Br(i.e., replacing two Se atoms by one As and one Br)is not reported. The physical origin for this puzzling disparity is unclear. In this work, we employ first-principles calculations to address this issue, and find that the distinct differences in stability between cation-transmutated(mix-cation) and anion-transmutated(mix-anion) compounds originate from their different trends of ionic radii as functions of their ionic state, i.e., for cations, the radius decreases with the increasing ionic state, whereas for anions, the radius increases with the increasing absolute ionic state. Therefore, for mix-cation compounds,the strain energy and Coulomb energy can be simultaneously optimized to make these materials stable. In contrast, for mix-anion systems, minimization of Coulomb energy will increase the strain energy, thus the system becomes unstable or less stable. Thus, the trend of decreasing strain energy and Coulomb energy is consistent in mix-cation compounds, while it is opposite in mix-anion compounds. Furthermore, the study suggests that the stability strategy for mix-anion compounds can be controlled by the ratio of ionic radii r3/r1, with a smaller ratio indicating greater stability. Our work, thus, elucidates the intrinsic stability trend of transmutated materials and provides guidelines for the design of novel ternary materials for various device applications.

关键词： stability stability ternary

Bioinspired 4D Trajectory Generation for a UAS Rapid Point-to-Point Movement

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Journal of Bionic Engineering 2014年第1期11卷 72-81页

作者： Zhen Zhang Shutao Zhang pu xie Ou Ma School of Mechatronic Engineering and Automation Shanghai University Shanghai 200072 P. R. China Department of Mechanical and Aerospace Engineering New Mexico State University Las Cruces NM 88003 USA

A bioinspired trajectory generation approach for Unmanned Aerial System （UAS） rapid Point-to-Point （PTP） movement was presented. The approach was based on general tau theory developed by biologists from observing and studying the behavior of birds and some other animals. We applied the bioinspired approach to the rapid PTP movement problem of a rotary UAS and derived two different trajectory planning strategies, namely, the tau coupling strategy and the intrinsic tau gravity guidance strategy. Based on general tau theory, according to the dynamic model of UAS, we presented a new strategy named intrinsic tau jerk guidance which can fit the movement that the initial acceleration of the UAS is zero. With new strategies, flight trajectory generation examples with a UAS were presented. The kinematics and dynamics analyses of the UAS for rapid PTP movement were presented with simulation results which show that the generated trajectories were feasible.

关键词： bioinspired trajectory generation tau theory jerk guidance rapid point-to-point movement

基于深度学习的全三维气固两相流时空耦合智能预测

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工程热物理学报 2024年第2期45卷 446-452页

作者：谢心喻王晓放郝祎琛赵普谢蓉刘海涛大连理工大学能源与动力学院大连116024

气固流化床在化工、冶金及制药等领域得到了广泛的研究与应用。对流化床内气固两相流的动力学行为进行深入研究有利于流化床设备的设计和性能优化。本文利用深度学习技术构建了数据驱动的全三维深度时空序列模型,对流化床内气固两相流... 详细信息

气固流化床在化工、冶金及制药等领域得到了广泛的研究与应用。对流化床内气固两相流的动力学行为进行深入研究有利于流化床设备的设计和性能优化。本文利用深度学习技术构建了数据驱动的全三维深度时空序列模型,对流化床内气固两相流三维空间和时间维度的复杂动力学行为进行学习,并实现了对未知来流速度条件下流化床内气相和颗粒相速度场的合理预测。测试结果表明,该全三维智能模型的预测结果与CFD计算结果高度一致,具有较好的泛化能力;此外,该模型比传统的数值仿真速度快数百倍,可以用于流场的快速预测,以缓解数值仿真耗时问题。

关键词：深度学习气固两相流三维时空预测流化床

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

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Acta Metallurgica Sinica(English Letters) 2015年第7期28卷 922-930页

作者： pu xie Hai-Yan Zhao Bing Wu Shui-Li Gong Department of Mechanical Engineering Tsinghua University State Key Laboratory of Tribology Tsinghua University Beijing Aeronautical Manufacture Technology Research Institute

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates（50 mm thick） by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.

关键词： Electron beam welding Residual stress Finite element method Contour method Titanium alloy

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回火工艺对HT9钢组织和力学性能的影响

金属热处理 2024年第3期49卷 44-50页

作者：谢谱赵吉庆颜廷亭昆明理工大学材料科学与工程学院云南昆明650093 钢铁研究总院有限公司特殊钢研究院北京100081

利用SEM、TEM、相分析和拉伸、冲击试验,研究了不同回火工艺对HT9钢组织演变及力学性能的影响。结果表明,回火工艺通过影响析出相和位错来改变钢的力学性能;HT9钢在回火后的基体组织为板条马氏体,强化相为M_(23)C_(6)碳化物,未观察到其... 详细信息

利用SEM、TEM、相分析和拉伸、冲击试验,研究了不同回火工艺对HT9钢组织演变及力学性能的影响。结果表明,回火工艺通过影响析出相和位错来改变钢的力学性能;HT9钢在回火后的基体组织为板条马氏体,强化相为M_(23)C_(6)碳化物,未观察到其他析出相。随着回火温度升高,基体组织发生回复,位错缠结逐渐规整、减薄为位错网络,形成亚晶,M_(23)C_(6)碳化物发生Ostwald熟化,析出强化和位错强化作用减弱,强度和硬度降低,韧性上升;在770℃回火1~12 h,随着回火时间延长,基体组织回复,M_(23)C_(6)相发生熟化,强度和硬度逐渐降低并伴有一定的时间依赖性。结合力学性能标准,热处理制度为1040℃淬火1 h+770℃回火6 h时,HT9钢的强韧性匹配较好。

关键词： HT9钢 M_(23)C_(6)相组织力学性能热处理工艺位错

High-fidelity Modeling of Multilayer Building Process in Electron Beam Powder Bed Fusion:Build-quality Prediction and Formation-Mechanism Investigation

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Chinese Journal of Mechanical Engineering(Additive Manufacturing Frontiers) 2023年第3期2卷 69-83页

作者： Chaochao Wu pu xie Muhammad Qasim Zafar Haiyan Zhao State Key Laboratory of Tribology Department of Mechanical EngineeringTsinghua UniversityBeijing100084China School of Mechanical Engineering and Automation Fuzhou UniversityFuzhou350108China Key Laboratory for Advanced Materials Processing Technology Ministry of EducationBeijing100084China Department of Aeronautics and Astronautics Stanford UniversityPalo Alto94305United States

High-fidelity simulations of powder bed fusion(PBF)additive manufacturing have made significant progress over the past decade.In this study,an efficient two-dimensional frame was developed for simulating the electron beam PBF process with hundreds of tracks for the direct prediction of the build quality.The applicable parameter range of the developed model was determined by comparing the heat transfer with that in three-dimensional cases.Subsequently,powder deposition and selective melting were coupled for a continuous simulation of the multilayer process.Three powder deposition models were utilized to generate random powder particles,and their effects on the packing structure and the resultant simulated build quality were investigated.The predicted build quality was validated using experimental results from independent studies.By reproducing the building process,the defect development mechanism in a multilayer process was revealed for the coalescence behaviors of randomly distributed powder particles,which also confirmed the importance of simulation at the high-fidelity powder scale.The effects of key process parameters during multilayer and multi-track processes on the build quality were systematically investigated.In particular,the formation statuses of all tracks during the simulated building process were recorded and analyzed statistically,which provided crucial information on the printing process for understanding the building mechanism or performing uncertainty analysis.

关键词： Powder bed fusion Electron beam melting Numerical simulation High-fidelity model Formation mechanism Build quality Defect

N/S co-doped 3D carbon framework prepared by a facile morphology-controlled solid-state pyrolysis method for oxygen reduction reaction in both acidic and alkaline media

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Journal of Energy Chemistry 2019年第7期28卷 220-226页

作者： Juan Nong Min Zhu Kun He Aosheng Zhu pu xie Minzhi Rong Mingqiu Zhang Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education DSAPM LabSchool of ChemistrySun Yat-sen UniversityGuangzhou 510275GuangdongChina China Building Materials Academy Beijing 100024China

Developing high-performance non-precious metal electrocatalysts for oxygen reduction reaction(ORR)is crucial for the commercialization of fuel cells and metal-air batteries.However,doped carbon-based materials only show good ORR activity in alkaline medium,and become less effective in acidic environment.We believe that an appropriate combination of both ionic and electronic transport path,and well dopant distribution of doped carbon-based materials would help to realize high ORR performance un-der both acidic and alkaline cond让ions.Accordingly,a nitrogen and sulfur co-doped carbon framework with hierarchical through-hole structure is fabricated by morphology-controlled solid-state pyrolysis of poly(aniline-co-2-ami no thiophenol)foam.The uniform high concentrations of nitrogen and sulfur,high intrinsic conductivity,and integrated three dimensional ionic and electronic transfer passageways of the 3D porous structure lead to synergistic effects in catalyzing ORR.As a result,the limiting current density of the carbonized poly(aniline-co-2-aminothiophenol)foam is equivalent to commercial Pt/C in acidic environment,and twice the latter in alkaline medium.

关键词： 3D N/S-doped carbon frameworks Oxygen reduction reaction(ORR) Morphology-retaining pyrolysis Acidic medium

基于VMD自适应模态重组的光学下变频信号分离方法

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强激光与粒子束 2024年第4期36卷 145-152页

作者：孙世腾谢树果宋雨杭濮晗春北京航空航天大学电子信息工程学院北京100191

光学下变频技术可将宽频带内全部电磁信号同时下变频到低频区间进行接收,是一种新型宽频带电磁环境快速接收技术。但是,获取的光学下变频信号中包含源个数未知、带宽不同的多种信号,现有信号分离方法需要获知源信号的个数,且无法同时分... 详细信息

光学下变频技术可将宽频带内全部电磁信号同时下变频到低频区间进行接收,是一种新型宽频带电磁环境快速接收技术。但是,获取的光学下变频信号中包含源个数未知、带宽不同的多种信号,现有信号分离方法需要获知源信号的个数,且无法同时分离窄带信号和宽带信号。为实现对光学下变频信号的自动分离,提出了一种基于变分模态分解(VMD)自适应模态重组的光学下变频信号分离方法。通过频谱分割因子和频谱包络检测,对光学下变频信号的VMD过分解模态进行自动重组和信号重组模态提取,实现光学下变频信号分离。对于包含普通脉冲信号、宽带码分多址(WCDMA)信号和线性调频脉冲信号的光学下变频信号,可自动实现对三种信号的分离,且与原信号的相似系数均高于0.97。实验结果表明,所提及方法在分离光学下变频信号时无需获知源信号的个数,并能同时分离具有不同带宽的多种源信号。

关键词：变分模态分解光学下变频单通道信号分离频谱分割因子频谱包络检测