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Natural vibration of cantilever porous twisted plate with variable thickness in different directions

Defence technology（防务技术） 2023年第9期27卷 200-216页

作者： Y.X.Hao Y.Y.Liu w.Zhang L.t.Liu K.C.Sun S.w.Yang College of Mechanical Engineering Beijing Information Science and Technology UniversityBeijing100192PR China College of Mechanical Engineering Beijing University of TechnologyBeijing100124PR China

In this paper,the blade is assumed to be a rotating variable thickness cantilever twisted plate structure,and the natural vibrations of variable thickness cantilever twisted plate made of metal porous material are *** is assumed that the thickness of the plate changes along spanwise direction and chordwise direction,respectively,and it changes in both *** classical thin shell theory,the first and second fundamental forms of surface and von Karman geometric relationship are employed to derive the total potential energy and kinetic energy of the cantilever twisted plate,in which the centrifugal force potential due to high rotational speed is ***,according to the Rayleigh-Ritz procedure and applying the polynomial functions which satisfy the cantilever boundary conditions,the dynamic system expressed by equations of motion is reduced to an eigenvalue *** numerical simulation,the frequency curves and the mode shapes of the twisted plate can be obtained to reveal the internal connection between natural vibration and the parameters.A series of comparison studies are performed to verify the accuracy of the present formulation and calculations,in which compared data come from experimental,finite element method and theoretical calculation,*** influence of pre-twist angle,three different forms of thickness taper ratio and rotational speed on natural vibration,mode exchange and frequency veering phenomenon of the system is discussed in *** addition,the approach proposed here can efficiently extract analytical expressions of mode functions for rotating variable thickness cantilever twisted plate structures.

关键词： Porous cantilever twisted plate Variable thickness Natural vibration Frequency veering Mode exchange

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Design and Analysis of an Outer-Rotor Parallel-Hybrid-Excited Vernier Machine

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Chinese Journal of Electrical Engineering 2017年第1期3卷 27-32页

作者： wenlong Li t.w.Ching K.t.Chau College of Computer Science and Software Engineering Shenzhen UniversityShenzhen518060China Faculty of Science and technology University of MacaoMacao999078China Department of Electrical and Electronic Engineering The University of Hong KongHong KongChina

In this paper,an outer-rotor parallel-hybrid-excited vernier machine is *** order to realize the parallel hybrid excitation,the homopolar configuration is adopted to artfully combine the permanent magnet(PM)flux path and the electromagnet flux path ***,the structure of the proposed machine is ***,its operating principle is studied and ***,its performance for flux regulation is analyzed based on the 3-D finite element ***,the prototype of the proposed machine is manufactured and tested to verify the analytical results.

关键词： Flux control parallel hybrid excitation PM machine vernier machine

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CORROSION BEHAVIORS OF tHE EXPOSED SIDE AND UNDERSIDE OF LOw ALLOY wEAtHERING StEEL IN QINGDAO AND wANNING FOR 18 MONtHS

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Acta Metallurgica Sinica(English Letters) 2008年第6期21卷 425-436页

作者： S. t. wang S. w. Yang K. w. Gao X.L. He Department of Materials Physics and Chemistry University of Science and Technology Beijing Beijing 100083 China

For 18 months, a newly developed low alloy weathering steel has been exposed in two coastal sites （Qingdao in the north China, wanning in the south China）. the different corrosion behaviors of the exposed side and the underside of the samples were characterized by X-ray diffraetion （XRD）, polarization curve, electrochemical impedance spectroscopy （EIS）, scanning electron microscopy （SEM）, and N2 adsorption approach. It was found that the samples exhibited higher corrosion rate in wanning than that in Qingdao. the underside of the samples corrodes more seriously than the exposed side in Qingdao, whereas the result in wanning is just the reverse. the protection performance of rust layers mainly depends on its compactness and the enrichment of Cu and Cr is a secondary causation. the different compactness of rust layers in the exposed side and the underside originates from different corrosion conditions of the two sides.

关键词： Low alloy weathering steel temperate marine environment Subtropical marine environment Exposed side Underside side

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tHE INtERFACIAL BEHAVIORS OF ALUMINUM MAtRIX COMPOSItE IN DIFFERENt wELDING MEtHODS

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Acta Metallurgica Sinica(English Letters) 2004年第1期17卷 55-60页

作者： w.Guo J.t.Niu J.F.Zhai G.t.Zhou M.Z.wang State Key Laboratory of Advanced welding Production technology Harbin Institute of Technology(HIT)Harbin150001China State Key Laboratory of Metal Matrix Composite Shanghai Jiaotong University.Shanghai 200030.China

Non-interlayer liquid phase diffusion welding (China Patent) and laser welding methods for aluminum matrix composite are mainly described in this paper. In the non-interlayer liquid phase diffusion welding, the key processing parameters affecting the strength of joint is welding temperature. when temperature rises beyond solidus temperature, the bonded line vanishes. the strength of joint reaches the maximum and becomes constant when welding temperature is close to liquid phase temperature. Oxide film in the interface is no longer detected by SEM in the welded joint. with this kind of technique, particle reinforced aluminum matrix composite Al2 O3p/6061Al is welded successfully, and the joint strength is about 80% of the strength of composite (as-casted). In the laser welding, results indicate that because of the huge specific surface area of the reinforcement, the interfacial reaction between the matrix and the reinforcement is restrained intensively at certain laser power and pulsed laser beam. the laser pulse frequency directly affects the reinforcement segregation and the reinforcement distribution in the weld, so that the weldability of the composite could be improved by increasing the laser pulse frequency. the maximum strength of the weld can reach 70% of the strength of the parent.

关键词： non-interlayer liquid phase diffusion welding Al2O3p/6061 Alaluminum matrix composite laser welding interface behavior reinforcement

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Application of particle splitting method for both hydrostatic and hydrodynamic cases in SPH

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Acta Mechanica Sinica 2018年第4期34卷 601-613页

作者： w.t.Liu P.N.Sun F.R.Ming A.M.Zhang College of Shipbuilding Engineering Harbin Engineering University

Smoothed particle hydrodynamics（SPH） method with numerical diffusive terms shows satisfactory stability and accuracy in some violent fluid–solid interaction problems. However, in most simulations, uniform particle distributions are used and the multi-resolution, which can obviously improve the local accuracy and the overall computational efficiency, has seldom been applied. In this paper, a dynamic particle splitting method is applied and it allows for the simulation of both hydrostatic and hydrodynamic problems. the splitting algorithm is that, when a coarse（mother） particle enters the splitting region, it will be split into four daughter particles, which inherit the physical parameters of the mother particle. In the particle splitting process,conservations of mass, momentum and energy are ensured. Based on the error analysis, the splitting technique is designed to allow the optimal accuracy at the interface between the coarse and refined particles and this is particularly important in the simulation of hydrostatic cases. Finally, the scheme is validated by five basic cases, which demonstrate that the present SPH model with a particle splitting technique is of high accuracy and efficiency and is capable for the simulation of a wide range of hydrodynamic *** particle hydrodynamics（SPH）method with numerical diffusive terms shows satisfactory stability and accuracy in some violent fluid–solid interaction ***,in most simulations,uniform particle distributions are used and the multi-resolution,which can obviously improve the local accuracy and the overall computational efficiency,has seldom been *** this paper,a dynamic particle splitting method is applied and it allows for the simulation of both hydrostatic and hydrodynamic *** splitting algorithm is that,when a coarse（mother）particle enters the splitting region,it will be split into four daughter particles,which inherit the physical parameters of the mother *** the pa

关键词： Smoothed particle hydrodynamics Particle splitting Particle refinement Solid wall boundary Fluid–structure interaction

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β-defensins and the epididymis： contrasting influences of prenatal, postnatal, and adult scenarios

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Asian Journal of Andrology 2016年第2期18卷 323-328,J0008页

作者： Camilla M Ribeiro Erick JR Silva Barry t Hinton Maria Christina w Avellar Section of Experime.ntaI.Endocrinology Department of Pharmacology Universidade Federal de Sao Paulo - Escola Paulista de Medicina Sao Paulo Brazil Department of Cell Biology University of Virginia School of Medicine Charlottesville Virginia USA Present address: Department of Pharmacology Institute Of Biosciences of BotucatuUniversidade Estadual Paulista 'Julio de Mesquita Filho' Botucatu Sao Paulo 186).8-970 Brazil.

β-defensins are components of host defense, with antimicrobial and pleiotropic immuno-modulatory properties. Research over the last 15 years has demonstrated abundant expression of a variety of β-defensins in the postnatal epididymis of different species. A gradient of region- and cell-specific expression of these proteins is observed in the epithelium of the postnatal epididymis. their secretion into the luminal fluid and binding to spermatozoa as they travel along the epididymis has suggested their involvement in reproduction-specific tasks. therefore, continuous attention has been given to various β-defensins for their role in sperm function and fertility. Although β-defensins are largely dependent on androgens, the underlying mechanisms regulating their expression and function in the epididymis are not well understood. Recent investigation has pointed out to a new and interesting scenario where β-defensins emerge with a different expression pattern in the wolffian duct, the embryonic precursor of the epididymis, as opposed to the adult epididymis, thereby redefining the concept concerning the multifunctional roles of β-defensins in the developing epididymis. In this review, we summarize some current views of β-defensins in the epididymis highlighting our most recent data and speculations on their role in the developing epididymis during the prenatal-to-postnatal transition, bringing attention to the many unanswered questions in this research area that may contribute to a better understanding of epididymal biology and male fertility.

关键词： androgens embryogenesis epididymis organogenesis β-defensins

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中国水稻白叶枯病菌系染色体DNA的RFLP谱型的初析

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作物学报 1996年第1期22卷 13-19页

作者：章琦王春莲 JanE.Leach R.J.nelson t.w.Mew 中国农业科学院北京100081 堪萨斯州立大学植物病理系国际水稻研究所

用2个DNA探针pJEL101和pBSavrXa10对78个水稻白叶枯病菌系进行RFLP分型,以分析其群体结构和遗传多样性。分别鉴定出16种RFLP标记带的谱型。以彼此的带位相似率达85％为界,可分为6簇。参试菌系的群体遗传多样性为0.77(用pJEL101),和0.83(... 详细信息

用2个DNA探针pJEL101和pBSavrXa10对78个水稻白叶枯病菌系进行RFLP分型,以分析其群体结构和遗传多样性。分别鉴定出16种RFLP标记带的谱型。以彼此的带位相似率达85％为界,可分为6簇。参试菌系的群体遗传多样性为0.77(用pJEL101),和0.83(用pBSavrXa10)。RFLP谱型分析表明:我国多数病原型为杂合组群。白叶枯病菌系的分子表现型的变异,远远大于致病型,两个探针都能有效分析我国菌系的群体结构,分子技术可用以进一步完善我国水稻与白叶枯病菌系之间的鉴别反应系统和新小种的侦察。

关键词：水稻白叶枯病菌系染色体 RFLP

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Fabrication of niobium doped Pb(Zr,ti)O_3 fibers by viscous polymer processing

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中国有色金属学会会刊：英文版 2006年第B1期16卷 29-32页

作者：徐玲芳陈文周静李君 t.w.Button 张斗赵春霞 Institute of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China State Key Laboratory of Advanced technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China Interdisciplinary Research Centre in Materials Processing University of Birmingham B15 2TTUnited Kingdom

A technique based on viscous polymer processing (VPP) was described, which can produce high ceramic content green fibers. PZt-5 ceramic powders were ball milled to get high dispersibility. the slurry prepared for VPP was a composition of PZt-5 powder, PVA binder and glycerin. High ceramic content PZt-5 fibers were extruded with the slurry. the results show that the ceramic powders have fine mean particle size of 0.54 μm, high specific surface area of 3.55 m2/g and zeta potential of 8.81 mV after 16 h milling. the fibers sintered at 1 280 ℃ for 4 h have pure perovskite structure and grains of 2-5 μm in size, with little pores or cracks. the ultimate tensile strength of sintered fibers is up to 13.84 MPa compared with 2.88 MPa of green fibers. the remnant polarization (Pr) and coercive field (Ec) of the fibers are 50.65 μC/cm2 and 2.45 kV/mm, respectively. this fiber can withstand an electric field of 9 kV/mm higher than the ceramic (5 kV/mm), which shows high directional and compact qualities.

关键词：铌掺杂 PZt-5纤维陶瓷纤维粘性聚合物过程钙钛矿型结构

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Functional-trait ecology of the plateau pika Ochotona curzoniae in the Qinghai-tibetan Plateau ecosystem

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Integrative Zoology 2019年第1期14卷 87-103页

作者： Andrew t.SMItH BADINGQIUYING Maxwell C.wILSON Brigitte w.HOGAN School of Life Sciences Arizona State UniversityTempeArizonaUSA School of Geographical Sciences Qinghai Normal UniversityXiningChina

Understanding a species’functional traits allows for a directed and productive perspective on the role a species plays in nature,and thus its relative importance to conservation *** functionaltrait ecology of the plateau pika Ochotona curzoniae is examined to better understand the resilience and sustainability of the high alpine grasslands of the Qinghai-tibetan Plateau(QtP).the key functional traits of plateau pikas are their abundance and behavior of digging extensive burrow *** pikas have been poisoned over a significant part of their original geographic distribution across the QtP,allowing comparison of ecological communities with and without *** all mammalian and avian carnivores,most of which are obligate predators on pikas,have been lost in regions where pikas have been *** endemic birds on the QtP nest in pika burrows;when pikas are poisoned,burrows collapse,and these birds are greatly reduced in *** to the biopedturbation resulting from their burrows,regional plant species richness is higher in areas with pikas than *** presence of pika burrows allows higher rates of infiltration during heavy monsoon rains compared to poisoned areas,possibly mitigating runoff and the potential for serious downslope erosion and ***,the functional traits of plateau pikas enhance native biodiversity and other important ecosystem functions;these traits are *** plateau pikas are not natural colonizers,active reintroduction programs are needed to restore pikas to areas from which they have been poisoned to restore the important functional ecological traits of pikas.

关键词： ecosystem engineer functional-trait ecology keystone species Ochotona curzoniae re-introduction

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tumor-infiltrating lymphocytes in the immunotherapy era

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Cellular & Molecular Immunology 2021年第4期18卷 842-859页

作者： Sterre t.Paijens Annege Vledder Marco de Bruyn Hans w.Nijman Department of Obstetrics and Gynecology University of GroningenUniversity Medical Center GroningenGroningenThe Netherlands

the clinical success of cancer immune checkpoint blockade(ICB)has refocused attention on tumor-infiltrating lymphocytes(tILs)across cancer *** outcome of immune checkpoint inhibitor therapy in cancer patients has been linked to the quality and magnitude of t cell,NK cell,and more recently,B cell responses within the tumor ***-of-the-art single-cell analysis of tIL gene expression profiles and clonality has revealed a remarkable degree of cellular heterogeneity and distinct patterns of immune activation and *** of these states are conserved across tumor types,in line with the broad responses observed *** this homology,not all cancer types with similar tIL landscapes respond similarly to immunotherapy,highlighting the complexity of the underlying tumor-immune *** observation is further confounded by the strong prognostic benefit of tILs observed for tumor types that have so far respond poorly to ***,while a holistic view of lymphocyte infiltration and dysfunction on a single-cell level is emerging,the search for response and prognostic biomarkers is just *** this review,we discuss recent advances in the understanding of tIL biology,their prognostic benefit,and their predictive value for therapy.

关键词： tumor infiltrating lymphocytes B cells t cells tertiary lymphoid structures immunotherapy

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