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Engineering 2022年第12期19卷 93-104页

作者： Jiepeng Liu Shu huang Jiang Li y.Frank Chen School of Civil Engineering&Key Laboratory of New technology for Construction of Cities in Mountain Area Ministry of EducationChongqing UniversityChongqing 400045China Central-South Architectural Design Institute Co. Ltd.Wuhan 430071China Department of Civil Engineering The Pennsylvania State UniversityPA 17057USA

A large-span steel–concrete composite beam with precast hollow core slabs(CBHCSs)is a relatively new floor structure that can be applied to various long-span ***,human-induced vibrations may present serviceability issues in such *** alleviate vibrations,both the walking forces excited by humans and the associated floor responses must be *** this study,150 load–time histories of walking,excited by 25 test participants,are obtained using a force measuring *** dynamic loading factors and phase angles in the Fourier series functions for one-step walking are ***,walking tests are performed on seven CBHCS specimens to capture the essential dynamic properties of mode shapes,natural frequencies,damping ratios,and acceleration time *** CBHCS floor system generally exhibits a high frequency(>10 Hz)and low damping(damping ratiotivity studies using the finite element method are conducted to investigate the vibration performance of the CBHCS floor system,where the floor thickness,steel beam type,contact time,and human weight are ***,analytical expressions derived for the fundamental frequency and peak acceleration agree well with the experimental results and are hence proposed for practical use.

关键词： Composite beam Hollow core slab Walking force Floor vibration Mode shape

Effect of temperature on Material transfer Behavior at Different Stages of Friction Stir Welded 7075-t6 Aluminum Alloy

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Journal of Materials Science & technology 2013年第10期29卷 955-960页

作者： S.D.Ji y.y.Jin y.M.yue S.S.Gao y.X.huang L.Wang Faculty of Aerospace Engineering Shenyang Aerospace University State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology

In this work, the morphologies of weld of 7075-t6 aluminum alloy via friction stir welding （FSW） were analyzed by optical microscopy, the temperature field was attained by numerical simulation, and the effect of temperature on material transfer behavior in the thermal-mechanical affected zone （tMAZ） at different stages was mainly investigated. the FSW process consists of three stages. It is very interesting to find that the maximum transfer displacement of material appears at the final stage of welding process, then at the stable stage and at the initial stage, which results from the difference of peak temperatures at different stages. At any stage, the material in tMAZ near the surface of weld transfers downwards, the material in the middle of weld moves upwards and the material near the bottom of weld hardly moves. In any cross section of weld, the largest transfer displacement of material appears in the middle of weld. the increase of rotational velocity and the decrease of welding speed are both beneficial to the transfer displacement of material in the middle of weld.

关键词： Friction stir welding 7075-t6 aluminum alloy thermal-mechanical affected zone Material transfer Numerical simulation

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淤地坝溃坝风险性评估综述

灾害学 2025年第1期40卷 123-128,134页

作者：黄波张耀南中国科学院西北生态环境资源研究院兰州甘肃730000 中国科学院大学北京1000493 国家冰川冻土沙漠科学数据中心兰州甘肃730000 甘肃省科学数据总中心兰州甘肃730000

淤地坝作为一种关键的防灾减灾设施,对于粮食生产、水资源保持和洪水控制等方面发挥着至关重要的作用。上世纪六七十年代修建的大部分淤地坝面临淤满失效问题,突发的暴雨、地震等自然灾害将极大概率引起溃决,从而导致引发更为严重的次... 详细信息

淤地坝作为一种关键的防灾减灾设施,对于粮食生产、水资源保持和洪水控制等方面发挥着至关重要的作用。上世纪六七十年代修建的大部分淤地坝面临淤满失效问题,突发的暴雨、地震等自然灾害将极大概率引起溃决,从而导致引发更为严重的次生灾害。该文通过梳理黄土高原淤地坝溃坝风险性评价文献,总结了现有淤地坝溃坝风险性评价方法。结果表明,传统淤地坝风险性评价方法对影响因素数据的依赖程度很高;选取评价因子及其权重赋予存在较强的主观经验性;缺乏大范围的风险评估。因此,该文建议整合数据驱动模型的研究思路,利用多源数据,区域尺度上开展淤地坝溃坝风险性评价,为相关部门提供更可靠的决策支持,及具有提高防灾减灾能力实践意义。

关键词：淤地坝溃坝数据工程风险性评价

Dynamic stiffness for thin-walled structures by power series

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第8期7卷 1351-1357页

作者： ZHU Bin LEUNG A.y.t. Department of Civil Engineering Zhejiang University Hangzhou 310027 China Department of Building and Construction City University of Hong Kong Hong Kong China

the dynamic stiffness method is introduced to analyze thin-walled structures including thin-walled straight beams and spatial twisted helix beam. A dynamic stiffness matrix is formed by using frequency dependent shape functions which are exact solutions of the governing differential equations. With the obtained thin-walled beam dynamic stiffness matrices, the thin-walled frame dynamic stiffness matrix can also be formulated by satisfying the required displacements compatibility and forces equilib-rium, a method which is similar to the finite element method (FEM). then the thin-walled structure natural frequencies can be found by equating the determinant of the system dynamic stiffness matrix to zero. By this way, just one element and several elements can exactly predict many modes of a thin-walled beam and a spatial thin-walled frame, respectively. Several cases are studied and the results are compared with the existing solutions of other methods. the natural frequencies and buckling loads of these thin-walled structures are computed.

关键词： Dynamic stiffness method thin-wall structures Power series Buckling

CONStRUCtION OF QUANtUM FIELD tHEORy OF DISLOCAtIONS BASED ON tHE NON-RIEMANNIANPLAStICIty

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Acta Metallurgica Sinica(English Letters) 1998年第6期11卷 405-411页

作者： t.Hasebe y.Imaida Doshisha Univ Kyoto Japan

A new microscopic approach was proposed, which bridges the order gap between the dislocation theory and the crystalline plasticity based on the quantum field theory of dislocations. the Ginzburg-Landau equation was derived rigorously from the quantized Hamiltonian for a crystal body containing a large number of dislocations, which gives the reaction-diffusion (RD) type differential equations. the RD equation describes periodic patterning shown in PSBs, etc.. relationship between the proposed theory and the concepts appeared in the non-Riemannian plasticity was extensively discussed by introducing the gauge field of dislocations. (Edited author abstract) 15 Refs.

关键词： crystalline plasticity field theory Non-Riemannian plasticity,dislocation theory gauge field

Processing and Performance of Alumina Fiber Reinforced Alumina Composites

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Journal of Materials Science & technology 2003年第4期19卷 337-340页

作者： P.y.Leet t.Uchijima t.yano Research Laboratory for Nuclear Reactors Tokyo Institute of Technology2-12-1O-okayamaMeguro-kuTokyo152-8550JapanResearch Laboratory for Nuclear ReactorsTokyo Institute of Technology2-12-1O-okayamaMeguro-kuTokyo152-8550JapanResearch Laboratory for Nuclear ReactorsTokyo Institute of Technology2-12-1O-okayamaMeguro-kuTokyo152-8550Japan

Processing of alumina fiber-reinforced alumina matrix composites by hot-pressing was described. the mechanical properties of the composites fabricated by different sintering conditions including temperature and pressure have been investigated. the results indicated that the higher sintering temperature and pressure corresponded to the higher bulk density and higher maximum strength of the composite, whereas the pseudo-ductility of the composite was lower. the preliminary results of the composite with monazite-coated fibers showed that maximum strength could be improved up to 35% compared with the noncoated fiber composite in the same sintering condition. Moreover, the fracture behavior of the composite changed from completely brittle fracture to non-brittle fracture under the suitable sintering conditions. SEM observation of the fracture surface indicated that the coating worked as a protective barrier and avoided sintering of the fibers together even at high temperature and pressure during densification process.

关键词： Al2O3/Al2O3 composites Mechanical properties Hot-pressing Fiber reinforced composites

Genes important for survival or reproduction in Varroa destructor identified by RNAi

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Insect Science 2019年第1期26卷 68-75页

作者： Zachary y.huang Guowu Bian Zhiyong Xi Xianbing Xie Department of Laboratory Animal Science Nanchang UniversityNanchangJiangxiChina Department of Entomology Michigan State UniversityEast LansingMIUSA Department of Microbiology and Molecular Genetics Michigan State UniversityEast LansingMI USA Ecology Evolutionary Biology and BehaviorMichigan State UniversityEast LansingMIUSA BEACON Center for the Study of Evolution in Action Michigan State UniversityEast LansingMIUSA

the Varroa mite,(Varroa destructor),is the worst threat to honey bee health *** explore the possibility of using RNA interference to control this pest, we determined the effects of knocking down various genes on Varroa mite survival and ***-stranded RNA (dsRNA)of six candidate genes (Da,Pros26S,RpL8, RpL11,RpPO and RpS13)were synthesized and each injected into Varroa mites,then mite survival and reproduction were *** of dsRNA for Da (Daughterless)and Pros26S (Gene for proteasome 26S subunit adenosine triphosphatase)caused a significant reduction in mite survival,with 3.57%±1.94% and 30.03%±11.43% mites surviving at 72 h post-inj ection (hpi),*** mites injected with green fluorescent protein (GFP)-dsRNA showed survival rates of 81.95%±5.03% and 82.36 ±2.81%,respectively. Injections of dsRNA for four other genes (RpL8,RpL11,RpPO and RpS13)did not affect survival significantly,enabling us to assess their effect on Varroa mite *** number of female offspring per mite was significantly reduced for mites injected with dsRNA of each of these four genes compared to their GFP-dsRNA *** of the target genes was verified by real-time polymerase chain reaction for two genes important for reproduction (RpL8,RpL11)and one gene important for survival (Pros26S). In conclusion,through RNA interference,we have discovered two genes important for mite survival and four genes important for mite *** genes could be explored as possible targets for the control of Varroa destructor in the future.

关键词： Apis mellijera reproduction RNAi survival Varroa destructor

Amplitude modulation and extreme events in turbulent channel flow

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Acta Mechanica Sinica 2018年第1期34卷 1-9页

作者： y.C.yao W.X.huang C.X.Xu AML Department of Engineering Mechanics Tsinghua University

Amplitude modulation of near-wall turbulence by large-scale structures in the outer layer is investigated by direct numerical simulation of turbulent channel flows at Reynolds number Re= 540, 1000, 2000. the effect of modulation is obvious in the two-point cross-section correlation map, and the correlation coefficients increase significantly with the Reynolds number. the influence of modulation is reflected in the tail of the probability density function of the near-wall flow signals, which expands as the Reynolds number increases. the flatness factor provides a quantitative description of the high fluctuation events due to modulation. Vortical structures associated with modulation are revealed by conditionally averaging the flow field of the near-wall extreme events, providing a depiction of how the influence of the large-scale structures penetrate towards the near-wall region.

关键词： Wall turbulence Amplitude modulation Flatness Extreme events

NUMERICAL MODELING OF SUSPENDED SEDIMENt tRANSPORt IN CHANNEL BENDS

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Journal of Hydrodynamics 2006年第4期18卷 411-417页

作者： huang Sui-liang JIAy．F,WANG Sam S. y. College of Environmental Science and Engineering Nankai University Tianjin 300071 China National Center for Computational Hydroscience and Engineering The University of Mississippi Oxford USA

An algorithm to compute three-dimensional sediment transport effect was proposed in this paper to enhance the capability of depth-averaged numerical models. this algorithm took into account of non-uniform distributions of flow velocities and suspended sediment concentrations along water depth, it significantly enhanced the applicability of 2D models in simulating open channel flows, especially in channel bends. Preliminary numerical experiments in a U-shaped and a sine-generated experimental channel indicate that the proposed method performs quite well in predicting the change of bed-deformation in channel bends due to suspended sediment transport. this method provides an effective alternative for the simulations of channel morphodynamic changes.

关键词： algorithm dispersion terms bends suspended sediment transport 2D numerical model

Exploring high thermal conductivity polymers via interpretable machine learning with physical descriptors

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npj Computational Materials 2023年第1期9卷 386-399页

作者： Xiang huang Shengluo Ma C.y.Zhao Hong Wang Shenghong Ju China-UK Low Carbon College Shanghai Jiao Tong UniversityShanghaiChina Materials Genome Initiative Center School of Material Science and EngineeringShanghai Jiao Tong UniversityShanghaiChina

the efficient and economical exploitation of polymers with high thermal conductivity(tC)is essential to solve the issue of heat dissipation in organic ***,the experimental preparation of functional polymers with high tC remains a trial-and-error process due to the multi-degrees of freedom during the synthesis and characterization *** informatics equips machine learning(ML)as a powerful engine for the efficient design of polymers with desired ***,available polymer tC databases are rare,and establishing appropriate polymer representation is still *** this work,we propose a high-throughput screening framework for polymer chains with high tC via interpretable ML and physical feature *** hierarchical down-selection process stepwise optimizes the 320 initial physical descriptors to the final 20 dimensions and then assists the ML models to achieve a prediction accuracy R2 over 0.80,which is superior to traditional graph ***,we analyze the contribution of the individual descriptors to tC and derive the explicit equation for tC prediction using symbolic *** high tC polymer structures are mostlyπ-conjugated,whose overlapping p-orbitals enable easy maintenance of strong chain stiffness and large group ***,we establish the connections between the individual chains and the amorphous state of *** chains with high tC have strong intra-chain interactions,and their corresponding amorphous systems are favorable for obtaining a large radius of gyration and causing enhanced thermal *** proposed data-driven framework should facilitate the theoretical and experimental design of polymers with desirable properties.

关键词： properties process chains