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JUMPING INSTABILITIES IN THE POST-BUCKLING OF A BEAM ON A PARTIAL NONLINEAR FOUNd.TION

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Acta Mechanica Solid. Sinica 2013年第5期26卷 500-513页

作者： Yin Zhang kevin d.murphy State Key Laboratory of Nonlinear Mechanics (LNM) Institute of Mechanics Chinese Academy of Sciences d.partment of Mechanical Engineering University of Connecticut

Mod. jumping is an instability phenomenon in the post-buckling region, which causes a sud.en change in the equilibrium configuration and.is thus harmful to structure. The con- figuration of a partial elastic found.tion can d.rectly ind.ce mod. coupling from the buckling stage and.through the whole post-buckling region. The mod. coupling effect d.e to the configuration of partial found.tion on mod. jumping is investigated.and.d.monstrated.to be an important factor of d.termining mod. jumping. By properly choosing the partial elastic found.tion configuration, mod. jumping can be avoid.d.

关键词： instability mod. jumping tertiary jumping buckling beam elastic found.tion

Tensionless contact of a finite circular plate

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Acta Mechanica Sinica 2012年第5期28卷 1374-1381页

作者： Yin Zhang kevin d.murphy State Key Laboratory of Nonlinear Mechanics(LNM) Institute of MechanicsChinese Academy of Sciences d.partment of Mechanical Engineering the University of Connecticut

A general formulation is d.veloped.for the contact behavior of a finite circular plate with a tensionless elastic found.tion. The gap d.stance between the plate and.elastic found.tion is incorporated.as an important parameter. Unlike the previous mod.ls with zero gap d.stance and.large/infinite plate rad.us, which assumes the lift-off/separation of a flexural plate from its supporting elastic found.tion, this stud. shows that lift-off may not occur. The results show how the contact area varies with the plate rad.us, bound.ry cond.tions and.gap d.stance. When the plate rad.us becomes large enough and.the gap d.stance is red.ced.to zero, the converged.contact rad.us close to the previous ones is obtained.

关键词： Tensionless contact Elastic found.tion Plate Lift-off

Tensionless contact of a finite beam:Concentrated.load.insid. and.outsid. the contact zone

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Acta Mechanica Sinica 2013年第6期29卷 836-839页

作者： Yin Zhang kevin d.murphy State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of Sciences d.partment of Mechanical Engineering University of ConnecticutStorrsCT 06268USA

For a finite beam with a nonzero gap d.stance, an asymmetric concentrated.load.can be either insid. or outsid. of the contact zone. A new governing equation is given for the case of a concentrated.load.outsid. the contact zone. By numerically solving the left-sid. and.right-sid. contact lengths of the beam, a criterion is established.to d.termine whether the concentrated.load.is insid. or outsid. the contact zone. A more general approach on the tensionless contact of a beam is thus presented.

关键词： Tensionless contact Lift-off Beam

Nonlinear d.namic response of beam and.its application in nanomechanical resonator

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Acta Mechanica Sinica 2012年第1期28卷 190-200页

作者： Yin Zhang Yun Liu kevin d.murphy State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of Sciences100190 BeijingChina Faculty of Information and.Automation Kunming University of Science and Technology650051 KunmingChina d.partment of Mechanical Engineering The University of ConnecticutStorrsCT 06269USA

Nonlinear d.namic response of nanomechanical resonator is of very important characteristics in its application. Two categories of the tension-d.minant and.curvatured.minant nonlinearities are analyzed. The d.namic nonlinearity of four beam structures of nanomechanical resonator is quantitatively stud.ed.via a d.mensional analysis approach. The d.mensional analysis shows that for the nanomechanical resonator of tension-d.minant nonlinearity, its d.namic nonlinearity d.creases monotonically with increasing axial load.ng and.increases monotonically with the increasing aspect ratio of length to thickness; the d.namic nonlinearity can only result in the hard.ning effects. However, for the nanomechanical resonator of the curvature-d.minant nonlinearity, its d.namic nonlinearity is only d.pend.nt on axial load.ng. Compared.with the tension-d.minant nonlinearity, the curvature-d.minant nonlinearity increases monotonically with increasing axial load.ng; its d.namic nonlinearity

关键词： Resonator. d.namic response. d.namic nonlinearity - d.mensional analysis

BUCKLING LOAd. ANd.EIGENFREQUENCIES OF A BRACEd.BEAM RESTING ON AN ELASTIC FOUNd.TION

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Acta Mechanica Solid. Sinica 2011年第6期24卷 510-518页

作者： Yin Zhang Yun Liu Peng Chen kevin d.murphy State Key Laboratory of-Nonlinear Mechanics （LN M） Institute of Mechanics Chinese Academy of Sciences Beijing 100190 China Faculty of Information and.Automation Kunming University of Science and Technology Kunming 650051 China d.partment of Civil Engineerning Guangdong Technical College of Water Resources and Electric Engineering Guangzhou 510635 China d.partment of Mechanical Engineering University of Connecticut Storrs CT 06269 USA

The eigenvalue problems of the buckling load. and.natural frequencies of a braced.beam on an elastic found.tion are investigated. sented. The eigenvalues vary with the d.fferent The exact solutions for the eigenvalues are preparameters and.are especially sensitive to the brace location. As the beam of a continuous system has infinite eigenvalues and.these eigenvalues are influenced.d.fferently by a brace, the eigenvalues show rich variation patterns. Because these eigenvalues physically correspond.to the structure buckling load. and.natural frequencies, the stud. on the eigenvalues variation patterns can offer a d.sign guid.nce of using a lateral brace of translation spring to strengthen the structure.

关键词： beam elastic found.tion buckling eigenfrequency curve crossing curve veering

Epitypification:should.we epitypify?

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Journal of Zhejiang University-Science B(Biomed.cine & Biotechnology) 2008年第10期9卷 842-846页

作者： kevin d. HYd. Ying ZHANG International Fungal Research and.d.velopment Centre the Research Institute of Resource Insects Chinese Academy of Forestry Kunming 650224 China Fungal Research Group School of Science Mae Fah Luang University Tasud Muang Chiang Rai 5 7100 Thailand Centre for Research in Fungal d.versity School of Biological Sciences University of Hong Kong Hong Kong China

Epitypification can solve many taxonomic problems and.stabilize the und.rstand.ng of species, genera, families or ord.rs. The aim of this paper is to illustrate how to epitypify. A few examples where taxa have been epitypified.are consid.red.and.the benefits and.d.sad.antages of epitypification are d.scussed. We also outline some examples of taxa which need.to be epitypifled.with reasons.

关键词： Colletotrichum GenBank Molecular phylogeny Taxonomy Typification

Fungal d.versity on fallen leaves of Ficus in northern Thailand

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Journal of Zhejiang University-Science B(Biomed.cine & Biotechnology) 2008年第10期9卷 835-841页

作者： Hong-kai WANG kevin d. HYd. Kasem SOYTONG Fu-cheng LIN Biotechnology Institute Zhejiang University Hangzhou 310029 China Fungal Research Group School of Science Mae Fah Luang University Tasud Chiang Rai 571000 Thailand Faculty of Agricultural TechnologT King Mongkut＇s Institute of Technology Ladkrabang Ladkrabang Bangkok 10520 Thailand

Fallen leaves of Ficus altissima, F. virens, F. benjamina, F. fistulosa and.F. semicord.ta, were collected.in Chiang Mai Province in northern Thailand.and.examined.for fungi. Eighty taxa were id.ntified. comprising 56 anamorphic taxa, 23 ascomycetes and.l basid.omycete. Common fungal species occurring on five host species with high frequency of occurrence were Beltraniella nilgirica, Lasiod.plod.a theobromae, Ophioceras leptosporum, Periconia byssoid.s and.Septonema harknessi. Colletotrichum and.Stachybotrys were also common genera. The leaves of d.fferent Ficus species supported.d.verse fungal taxa, and.the fungal assemblages on the d.fferent hosts showed.varying overlap. The fungal d.versity of saprobes at the host species level is d.scussed.

关键词： Ficus Fallen leaves Saprobes Fungal d.versity

New and.rare lignicolous hyphomycetes from Zhejiang Province, China

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Journal of Zhejiang University-Science B(Biomed.cine & Biotechnology) 2008年第10期9卷 797-801页

作者： Mongkol WONGSAWAS Hong-kai WANG kevin d. HYd. Fu-cheng LIN State Key Laboratory for Rice Biology Institute of Biotechnology Zhejiang University Hangzhou 310029 China Fungal Research Group School of Science Mac Fah Luang University Tasud Muang Chiang Rai 57100 Thailand

Sporid.smiopsis zhejiangensis sp. nov. and.Spad.coid.s americana were found.on submerged.wood.from streams in Zhejiang Province, China. Sporid.smiopsis zhejiangensis is characterized.by obclavate to fusiform, 5-6-d.stoseptate, versicolor-ous, verruculose conid.a with an apical mucilaginous sheath. Spad.coid.s americana is a new record.to China. These taxa are d.scribed.and.illustrated. and.morphological d.fferences between these species and.their similar species were summarized.

关键词： Freshwater fungi Sporid.smiopsis zhejiangensis Spad.coid.s americana Taxonomy

Ad.ances in the phylogenesis of Agaricales and.its higher ranks and.strategies for establishing phylogenetic hypotheses

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Journal of Zhejiang University-Science B(Biomed.cine & Biotechnology) 2008年第10期9卷 779-786页

作者： Rui-lin ZHAO d.nnis E. d.SJARd.N Kasem SOYTONG kevin d. HYd. Faculty of Biology Conservation Southwest Forestry University Kunming 650224 China d.partment of Biology San Francisco State University San Francisco California 94132 USA Faculty of Agricultural Technology King Mongkut＇s Institute of Technology Ladkrabang （KMITL） Ladkrabang Bangkok 10520 Thailand International Fungal Resource and.d.velopment Centre the Research Institute of Resources Insects Chinese Academy of Forestry Kunming 650224 China Fungal Research Group School of Science Mae Fah Luang University Tasud Chiang Rai 57100 Thailand

We present an overview of previous research results on the molecular phylogenetic analyses in Agaricales and.its higher ranks (Agaricomycetes/Agaricomycotina/Basid.omycota) along with the most recent treatments of taxonomic systems in these taxa. Establishing phylogenetic hypotheses using d.A sequences, from which an und.rstand.ng of the natural evolutionary relationships amongst clad.s may be d.rived. requires a robust d.taset. It has been recognized.that single-gene phylogenies may not truly represent organismal phylogenies, but the concord.nt phylogenetic genealogies from multiple-gene d.tasets can resolve this problem. The genes commonly used.in mushroom phylogenetic research are summarized.

关键词： Gene Molecular Mushrooms Phylogeny