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Roles of soil-structure interaction and damping in base-isolated structures built on numerous soil layers overlying a half-space

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Earthquake Engineering and Engineering Vibration 2016年第2期15卷 387-400页

作者： C.S.Tsai C.i.hsueh h.C.Su Department of Civil Engineering Feng Chia University Graduate institute of Civil & hydraulic Engineering Feng Chia University Department of Water Resources Engineering and Conservation Feng Chia University

This study examines the roles of soil-structure interaction （SSi）, higher modes, and damping in a base-isolated structure built on multiple layers of soil overlying a half space. Closed-form solutions for the entire system, including a superstructure, seismic isolator, and numerous soil layers overlying a half-space, were obtained. The formulations obtained in this study simply in terms of well-known frequencies and mechanical impedance ratios can explicitly interpret the dynamic behavior of a base-isolated structure interacting with multiple soil layers overlying a half-space. The key factors influencing the performance of the isolation system are the damping ratio of the isolator and the ratio of the natural frequency of the fixed-base structure to that of the isolated structure by assuming that the superstructure moves as a rigid body. This study reveals that higher damping in the base isolator is unfavorable to higher mode responses that usually dominate the responses of the superstructure and that the damping mechanism plays an important role in transmitting energy in addition to absorbing energy. it is also concluded that it is possible to design a soft soil layer as an isolation system for isolating vibration energy.

关键词： base isolation seismic isolation soil-structure interaction closed- form solution higher-mode effects soilstratum passive control damping effects

Spectroscopic Study of a Radio-Frequency Atmospheric Pressure Dielectric Barrier Discharge with Anodic Alumina as the Dielectric

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Plasma Science and Technology 2013年第9期15卷 900-903页

作者： h.i.A.QAZi M.ShARiF S.hUSSAiN M.A.BADAR h.AFZAL Department of Physics University of SargodhaSargodha 40100Pakistan Department of Physics GC UniversityFaisalabad 38000Pakistan

This paper presents the fabrication and a spectroscopic study of a stable radio- frequency dielectric barrier discharge （RF DBD） in Ar with a novel dielectric, anodic alumina, at atmospheric pressure. Dielectric electrodes are fabricated from commercially available low cost impure aluminum strips by a two-step anodization process in 0.3 M solution of oxalic acid. The discharge is found to be stable with excellent spatial uniformity for the RF input power range of 30～80 W. Excitation and rotational temperatures measured in the experiment range of 1472～3255 K and 434～484 K, respectively, as the input power changes from 30 W to 80 W. These temperature ranges are suitable for surface modification applications.

关键词： radio frequency atmospheric pressure glow discharge dielectric barrier dis-charge anodic alumina dielectric

Evaluation of microstructure and mechanical properties of Mg-xCe-0.5Zn alloys by nano-indentation

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Transactions of Nonferrous Metals Society of China 2010年第7期20卷 1240-1243页

作者： K.C.PARK B.h.KiM Y.h.PARK i.M.PARK Department of Material Science and Engineering Pusan National UniversitySan 30 Jangjeon-dongGeumjeong-guBusan 609-735Korea

The microstructure and mechanical properties of Mg-xCe-0.5Zn （x=0.5, 1.5, 2.5, molar fraction, %） alloys were examined using a nano-indentation technique. The alloys were fabricated using a vacuum induction melting method under an argon atmosphere The microstruetures of Mg-xCe-0.5Zn alloys mainly consist ofa-Mg and eutectic Mg12Ce phase. The volume fraction and size of the eutectic Mgl2Ce phase increase with increasing Ce contents. Nano-indentation test results show that the indentation hardness and elastic modulus of the eutectic Mg12Ce phase are higher than those of the a-Mg matrix. in addition, the mean indentation hardness and elastic modulus of the Mg-xCe-0.5Zn alloys increase with the Ce addition amount increasing.

关键词： Mg alloys Mg-Ce-Zn rare earth microstructure mechanical properties nano-indentation

Thermoluminescence Responses of Photon and Electron irradiated Ge- and Al-Doped SiO_(2) Optical Fibres

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Chinese Physics Letters 2012年第2期29卷 208-210页

作者： h.Wagiran i.hossain D.Bradley A.N.h.Yaakob T.Ramli Department of Physics Universiti Teknologi Malaysia81310 SkudaiJohor Darul TakzimMalaysia Department of Physics University of SurreyGuildfordGU27XHUK

We carry out a comparison of the thermoluminescence (TL) response of photon and electron irradiated Ge- and Al-doped SiO_(2) optical fibres,as well as cross-comparison with that of *** is made with 6 MeV electrons and 6 MV photons,for doses ranging from 0.2 Gy to *** commercially available Al- and Gedoped optical fibres produce a linear dose-TL *** TL yield for both of the doped fibres and also for TLD-100 is greater for electron irradiation than for photon *** TL yield of the Al-doped fibres is a small fraction of that of Ge-doped fibres (by a factor of 25),the Ge-doped fibres offering a response of 59%o of that of TLD-100.

关键词： irradiation Electron irradiated

interaction between compressibility and particulate suspension on peristaltically driven flow in planar channel

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Applied Mathematics and Mechanics(English Edition) 2017年第1期38卷 137-154页

作者： i.M.ELDESOKY S.i.ABDELSALAM R.M.ABUMANDOUR M.h.KAMEL K.VAFAi Department of Basic Engineering Sciences Faculty of EngineeringMenoufia UniversityMenoufia 32511Egypt Department of Mechanical Engineering University of CaliforniaCalifornia 92521U.S.A. Basic Science Department Faculty of EngineeringThe British University in EgyptCairo 11837Egypt Department of Engineering Mathematics and Physics Faculty of Engineering Cairo UniversityGiza 12613Egypt

The peristaltic pumping of a viscous compressible liquid mixed with rigid spherical particles of the same size in a channel is theoretically investigated. The momentum equations for the compressible flow are solved with a perturbation analysis. The analysis is carried out by duly accounting for the nonlinear convective acceleration terms for the fluid part on the wavy wall. The zeroth-order terms yield the Poiseuille flow, and the first-order terms give the Orr-Sommerfeld equation. The explicit expression for the net axial velocity is derived. The effects of the embedded parameters on the axial fluid velocity are studied through different engineering applications. The features of the flow characteristics are analyzed and discussed in detail. The obtained results are evaluated for various parameters associated with the blood flow in the blood vessels with diameters less than 5 500 μm, whereas the particle diameter has been taken to be 8 μm. This study provides a scope to evaluate the effect of the theory of two-phase flow characteristics with compressible fluid problems, and is helpful for understanding the role of engineering applications of pumping solid-fluid mixture by peristaltically driven motion.

关键词： two-phase flow peristaltic transport compressible liquid perturbation method

植物系统发生海报——以演化视角介绍植物多样性的科教资料项目

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生物多样性 2025年

作者：蒋陈焜郁文彬饶广远黎怀成 Julien B.Bachelier hartmut h.hilger Theodor C.h.Cole 北京大学生命科学学院蛋白质与植物基因研究国家重点实验室北京大学前沿交叉学科研究院北京大学-清华大学生命科学联合中心中国科学院西双版纳热带植物园综合保护中心/云南省热带雨林与亚洲象保护重点实验室 Dahlem Centre of Plant Sciences (DCPS)， institute of Biology， Structural and Functional Plant Diversity， Freie Universit?t Berlin

中国的植物多样性保护行动虽然提升了公众对多样性的认识，但这些努力往往未能深入到理解植物多样性演化及其保护的深层意义。从演化的视角进行植物多样性宣传教育，有利于促进对多样性的综合理解，增进对多样性保护的认可。然而， ... 详细信息

中国的植物多样性保护行动虽然提升了公众对多样性的认识，但这些努力往往未能深入到理解植物多样性演化及其保护的深层意义。从演化的视角进行植物多样性宣传教育，有利于促进对多样性的综合理解，增进对多样性保护的认可。然而，现有资料多集中于物种的识别、鉴定与分类，缺乏从生物演化角度对植物多样性进行系统性介绍的内容。本文介绍了一个具有全球影响力的科教资料案例——由美裔德国植物学家Theodor C. h. Cole发起的植物系统发生海报(Plant Phylogeny Posters)项目。该项目通过整合最新的系统与演化植物学研究成果，以系统发生为线索介绍植物多样性及其亲缘关系，旨在利用系统发生树所蕴含的丰富演化思想内涵，启发读者理解植物多样性与演化。海报以系统发生树结合植物类群的形态、地理分布、物种数量等数据信息，直观展示了多个分类等级的重要类群的演化历史。在数十所大学和科研机构的45位研究人员的努力下， 70张系统发生海报已被翻译成中文，并向所有人免费开放获取。这一科教项目有望为增进公众深入理解植物多样性及其保护行动提供宝贵的资源和帮助。

关键词：植物多样性演化系统发生科教资料

Soft coral Cespitularia stolonifera:New cytotoxic ceramides and gastroprotective activity

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Chinese Journal of Natural Medicines 2017年第2期15卷 105-114页

作者： Abdelsamed i.Elshamy Walaa A.El-Kashak heba M.i.Abdallah Abdelrazik h.Farrag Mahmoud i.Nassar Natural Compounds Chemistry Department National Research CentreGiza 12622Egypt Pharmacology Department National Research CentreGiza 12622Egypt Pathology Department National Research Centre Giza 12622Egypt

in the present study, a new ceramide, namely 2S, 3R-4E, 8E-2-(heptadecanoylamino)-heptadeca-4, 8-diene-1, 3-diol(1), along with four known steroids, including 24-methylcholesta-5, 24(28)-diene-3β-ol(2), 24-methylcholesta-5, 24(28)-diene-3β-acetate(3), 4-methyl-24-methylcholesta- 22-ene-3-ol(4), and cholesterol, was isolated and characterized from Ch2Cl2/Me Oh extract of Cespitularia stolonifera. A new acetate derivative of compound 1, termed 2S, 3R-4E, 8E-2-(heptadecanoylamino)-heptadeca-4, 8-diene-1, 3-diacetate(1a), was also prepared in the present study. All the structures were established on the basis of modern spectroscopic techniques, including FT-iR, 1D, 2D-NMR, hRESi-MS, and GC-MS, in addition of chemical methods.(-)-Alloaromadendren, ledane,(1)-alloaromadendren oxide, isoaromadendrene epoxide and(-)-caryophellen oxide were identified from the n-hexane fraction using GC-MS. The extract and the two ceramides(1) and(1a) exhibited significant cytotoxic activity against lung cancer A549 cells, while the extract and the two steroids(2) and(3) exhibited significant cytotoxic activity against breast cancer MCF-7 cells. The Ch_2Cl_2/MeOh extract exhibited significant antiulcer activity in both ethanol and acetic acid induced ulcer models in rats, as evidenced by histopathological, histochemical, and biochemical examinations.

关键词： Cespitularia stolonifera Ceramide Steroids Anticancer leading constituents Antiulcer activity

CORROSiON AND MEChANiCAL PROPERTiES OF Ti_3Al-Nb-Mo COMPOSiTES FOR BiO-AND ENViRONMENTAL MATERiALS PREMRED BY SELF-PROMGATiNG hiGh TEMPERATURE REACTiON

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Acta Metallurgica Sinica(English Letters) 2002年第2期15卷 149-153页

作者： Y.Choi N.i.Baik h.D.Cho S.i.hong Department of Metallurgical and Materials Engineering Sunmoon University#100 Kalsan-RiTangjeoung-MyunAsanChungnam336-840Korea Department of Environmental Engineering Sunmoon University#100 Kalsan-RiTangjeoung-MyunAsanChungnam336-840Korea Department of Metallurgical Engineering Chungnam National UniversityDaejeon305-764Korea Manuscript received 31 July 2001

Ti3 AL-Nb-Mo composites were prepared by ShS using initial powder mixtures of Ti-Al-Nb-Mo and their corrosion and mechanical properties were studied to develop bioand environmental materials. The composites reached 99.8% of theoretical density after the direct consolidation. The composites shows equiaxed primary a2 in a matrix of fine secondary a2 plates and ordered 82 (Bo) forming a basket weave structure. The strain rate sensitivity (m = dlnσ/dlne) at 2% strain is 0.008. Corrosion potential and corrosion rate of the composites formed by ShS were -151. 5m VShE and 5. 72× 10^(-8)A/cm2 for Ti3 Al-10Nb-1. 5Mo and - 138.4m VShE and 4. 12×10^(-8)cm2 for Ti3 Al-12Nb-1.5Mo in a 50% NaOh-10%FeCi3 solution, respectively. Corrosion resistance decreased with niobium content in the composites and chloride content in the aqueous solution. Selective corrosion of a2 phase in a matrix occurred in the corrosion environment which suggests that the corrosion potential and rate changes are related to the niobium content and Q2 phase in a matrix.

关键词： Ti3 Al alloy corrosion strength ShS

inhomogeneous dealloying kinetics along grain boundaries during liquid metal dealloying

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Journal of Materials Science & Technology 2022年第11期106卷 41-48页

作者： S.-h.Joo Y.B.Jeong T.Wada i.V.Okulov h.Kato Department of Materials Science and Engineering Dankook University119 Dandae-roCheonan 31116Korea institute for Materials Research Tohoku UniversityKatahira 2-1-1Sendai 980-8577Japan institute of Natural Sciences and Mathematics Ural Federal University620000 EkaterinburgRussia Faculty of Production Engineering University of BremenBadgasteiner Str.128359 BremenGermany Leibniz institute for Materials Engineering-iWT Badgasteiner Str.328359 BremenGermany

in this study, the inhomogeneous dealloying phenomenon during the liquid metal dealloying(LMD) was investigated using FeNi+Mg and(FeCo)Ni+Mg systems. For the FeNi+Mg system, the inhomogeneous dealloying and wetting of Mg melt occurred along triple junction(TJ) and grain boundary(GB).Temperature increase enhances the inhomogeneous dealloying kinetics and leads to the formation of the plate-shaped abnormal ligaments at the GB region. The energy banlance between a GB energy(γGB)and solid-liquid interface energies(γsl) is the key factor governing the inhomogeneous dealloying and wetting. Particularly, the low-energy twin boundaries were unaffected by the inhomogeneous ***, precursor microstructure is an important factor determining the final morphology of dealloyed material as well as its physical properties. in the case of the(FeCo)Niprecursor, all TJ and GB were stable against the preferred penetration of Mg melt from 600 ℃ to 800 ℃. it was concluded that a minor addition of alloying elements(VorCr) changes GB characteristics as well as γslof the precursor ***, this significantly influences dealloying mechanisms and final morphology of the dealloyed material. The current findings demonstrate the importance of GB engineering in the precursor materials for the technological application of liquid metal dealloying for the synthesis of advanced structural and functional materials.

关键词： Liquid metal dealloying inhomogeneous dealloying Dealloying mechanism Abnormal ligament Porous material