41 resultados para walking stick

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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Objective speckle from a stick-on foil is a new approach to applying the objective white light speckle method to in-plane displacement measurements. By a relatively easy technique a thin aluminum foil is mounted onto the specimen surface and a random grating is scratched onto it, yielding high reflectance and fine optical details. After double exposure by a direct recording system without using a lens, the resulting holographic film possesses a broad spatial spectrum and displacement information. Full-field contour maps of equal displacement can be obtained that are of good contrast and high sensitivity and that have a large adjustable measurement range. The method can be applied to practical engineering problems for both plane and developable curved surfaces.

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This paper describes a portable recording system and methods for obtaining chronic recordings of single units and tracking rhesus monkey behavior in an open field. The integrated system consists of four major components: (1) microelectrode assembly; (2) h

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Exploratory experiments of laser welding cast Ni-based superalloy K418 turbo disk and alloy steel 42CrMo shaft were conducted. Microstructure of the welded seam was characterized by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive spectrometer (EDS). Mechanical properties of the welded seam were evaluated by microhardness and tensile strength testing. The corresponding mechanisms were discussed in detail. Results showed that the laser-welded seam had non-equilibrium solidified microstructures consisting of FeCr0.29Ni0.16C0.06 austenite solid solution dendrites as the dominant and some fine and dispersed Ni3Al gamma' phase and Laves particles as well as little amount of MC short stick or particle-like carbides distributed in the interdendritic regions. The average microhardness of the welded seam was relatively uniform and lower than that of the base metal due to partial dissolution and suppression of the strengthening phase gamma' to some extent. About 88.5% tensile strength of the base metal was achieved in the welded joint because of a non-full penetration welding and the fracture mechanism was a mixture of ductility and brittleness. The existence of some Laves particles in the welded seam also facilitated the initiation and propagation of the microcracks and microvoids and hence, the detrimental effects of the tensile strength of the welded joint. The present results stimulate further investigation on this field. (c) 2006 Elsevier B.V. All rights reserved.

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In this paper, we investigate the adhesive contact between a rigid cylinder of radius R and a graded elastic half-space with a Young's modulus varying with depth according to a power-law, E = E-0(y/c(0))(k) (0 < k < 1), while the Poisson's ratio v remains constant. The results show that, for a given value of ratio R/C-0, a critical value of k exists at which the pull-off force attains a maximum; for a fixed value of k, the larger the ratio R/c(0), the larger the pull-off force is. For Gibson materials (i.e., k = 1 and v = 0.5), closed-form analytical solutions can be obtained for the critical contact half-width at pull-off and pull-off force. We further discuss the perfect stick case with both externally normal and tangential loads.

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A process of laser cladding Ni-CF-C-CaF2 mixed powders to form a multifunctional composite coatingd on gamma-TiAl substrate was carried out. The microstructure of the coating was examined using XRD, SEM and EDS. The coating has a unique microstructure consisting of primary dendrite or short-stick TiC and block Al4C3 carbides reinforcement as well as fine isolated spherical CaF2 solid lubrication particles uniformly dispersed in the NiCrAlTi (gamma) matrix. The average microhardness of the composite coatings is approximately HV 650 and it is 2-factor greater than that of the TiAl substrate. (C) 2008 Elsevier B.V. All rights reserved.

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刺叶栎( Quercus ilex L.)是地中海的常绿树种,属于古老的第三纪植物区系成份。本文根据苏黎世——蒙特利尔学派的植被学基本原理,全面地研究了分布在整个威尼托(Veneto)大区的剌叶栎林,详细研究刺叶栎林的群落组成、结构及类型划分。同时,对威尼托的刺叶栎林同北京山区的栎林进行了比较研究。最后,着重研究了威尼托刺叶栎林的生物多样性。 威尼托的刺叶栎林主要分布在亚得里亚海沿岸(包括Foci del Tagtiamento和Bosco Nordio e Rosolina Mare两地)、Lago di Garda和Colli Euganei。 在气候上,亚得里亚海沿岸属于半地中海气候。加尔达湖区域(Laqo di Garda)则是接近欧洲中部的大陆性气候,且维持半地中海的气候特点。Co t l i Euganei是这两地气候的过渡类型,且更接近亚得里亚海沿岸的类型。 在亚得里亚海沿岸的刺叶栎林可以分为三类,第一类(I)是一些矮树丛,这是Fraxinus ornus和Quercus ilex混交林的前身,较干旱。第二类群落(II)缺少乔木层,灌木层是由一些盖度不大的刺叶栎代替,更干旱。第三类群落(Ⅲ)是一群在外貌上相同的成熟群落.Fraxinus ornus和Quercus ilex得到充分发展,较中生。 在加尔达湖区的刺叶栎林可划分为三类。第一类群落(I)代表一组耐旱、开敞的矮树丛,含有Sesterio Variae-Ostryelum群丛的特征种,这一类可划分为SesLerio Variae-Ostryetum群 丛,土壤贫脊和干旱。第二类群落(Ⅱ)代表一类较郁闭的矮树丛,含有较多的Prunetalia群落目的成份,土壤较贫脊。第三类群(Ⅲ)代表一类郁闭的群落,乔木具有很大的密度因而林下灌木不能充分发展。SesLerio Variae-Ostryetum群丛和Prunetalia群落目的成份均不多。 在Colli Euganei的刺叶栎林可划分为二类。第一类群落(I)是一些不郁闲的矮树林组成。大体上分为地中海旱生栎林和地中海假灌丛。第二类群落(II)代表了较中生状态的植被,刺叶标种群绝对郁闭。 北京地处华北大平原的西北部。北京山地的气候为温带陆地性季风气候,其地带性的落叶阔叶林是以栎林为典型。虽然这些栎林同意大利威尼托刺叶栎林是两种不同的森林类型,但两者之间是存在着一定的联系。其共有的科有20个,共有属有11个。他们在植物组成中,以禾本科,蔷薇科和豆科的植物种类为最多。在乔木层中,他们都是以壳斗科的栎属(Quercus)为优势,其中木犀科的白蜡属(Fraxinus)和槭树属(Acer)较多。 本文对威尼托大区刺叶栎林的物种多度分布格局进行了全面探讨,计算出刺叶栎林的几何分布模型、Broken-stick分布模型、Log分布模型、Log-normat分布模型等四种物种多度分布的理论模型,并将这些理论分布模型用“序列/多度”图解和“多度/频度”图解表示出来。其中,几何分布模型.Broken-stick1分布模型用“序列/多度”图解表示。Broken-stick2分布模型、Log分布模型、Log-normal分布模型用“多度/频度”图解表示。 对上述四个物种多度的理论分布同实际现察的物种多度分布进行X2分析,在5%的显著性水平上,对整个威托大区的刺叶 栎林,几何分布模型最能代表其物种多度分布,显著性最大;Log-normal分布模型也可以用来代表威尼托刺叶标妹的物种多度分布,其显著性次于几何分布模型的显著性。这表明威尼托的刺叶栎林尚处于演替的早期阶段,这些刺叶栎林曾受到严重破坏,现正在恢复。 通过比较Foci del Tagtiamento和Bosco Nordio加尔达湖区、Colli Euganei四个地方刺叶栎林的物种多度的几何分布模型和Log-normal分布模型,显示出Lago di Garda(加尔达湖区)的刺叶栎林生物多样性最好、Foci del Tagtiamento刺叶栎林生物多样性较好.Bosco Nordio的剌叶栎林生物多样性较差.Colli Euganei的刺叶栎林生物多样性最差。 再利用多样性指数计算全部威尼托大区剌叶栎林的生物多样性。计算的多样性指数有丰富度指数(包括Margalef指数、Men-hinick指数、Monk指数)、多样性指数(Shannon信息指数、Bri llouin个息指数、Gini指数、PIE指数、Mcintosh指数)、优势度指数(Berger-Parker指数、Simpson指数)、均一度指数(Pielou均一度指数、Brillouin均一度指数,PIE的V’均一度指数.PIE的V均一度指数,N2的V’均一度指数,N2的V均一度指数,Mclntosh均一度指数,Hill的F10均一度指数,Hill的E21均一度指数,Hill的F21的一度指数)。通过比较丰富度指数,多样性指数、均一度指数与优势度之间的关系,结果,Simpson优势度指数同Men-hinick物种丰富度指数、Shannon信息指数、Bril-louin信息指数、Pielou均一度指数,Brillouin均一度指数,Mcintosh均一度指数、PIE的V’均一度指数呈负相关关系,因此,上述生物多样性指数可以较好地反映威尼托大区刺叶栎林的生物多样性。反映出的结果是:加尔达湖区刺叶栎林生物多样性最好,Foci del Tagtiamento刺叶栎林生物多样性较好,Bosco Nordio的剌叶栎林生物多样性较差.Colli Euganei的刺叶栎林生物多样性最差。 生物多样性的研究显示出生物多样性同生境状况的密切联系。往往受人为干扰严重的群落生物多样性低、如Coli Euganei和亚得里亚海岸刺叶栋林;而受人为破坏较轻的群落其生物多样性高,如加尔达湖区刺叶栎。 生物多样性的研究还显示出生物多样性同群落演替的发展阶段密切相关,在群落演替初期,由于缺乏优势种,而又有大量物种侵入,物多样性相对较高。在群落演替中期,由于形成了一个或几个优势种,优势度的增加导致了生物多样性相对减低。如Foci del Tagtiamento刺叶栎林生物多样性高于Bosco Nordio刺叶栎林的生物多样性。到演替后期,随着更多物种的侵入,群落结构的复杂化、生物多样性又将逐步提高。

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Aspects of the behaviour of three groups of Yunnan snub-nosed langurs, Rhinopithecus bieti, were observed over the course of three field seasons from 1986 to 1988. The major findings of the study were: (1) The habitats of R. bieti were mainly at heights of 3,600-4,150 m above sea level. (2) Groups were very large, with group sizes ranging from more than 100 to 269 individuals. (3) Spatial dispersion densities ranged from about 27 to 106 m2/individual during sleeping and resting, to feeding dispersions as large as 5,000-15,000 m2. (4) The locomotor repertoire of R. bieti consisted largely of walking, jumping and climbing. On very rare occasions, semibrachiation was observed, but true brachiation was never observed. The locomotor repertoires of juveniles were more diverse than those of subadults or adults. (5) Communication consisted mainly of eye-to-eye contact accompanied by murmurs; while loud calls were heard only rarely. (6) Groups moved between sleeping and feeding sites in single file. It is concluded that R. bieti is a mainly terrestrial species.

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Gibel carp ( Carassius auratus gibelio) is a uniquely gynogenetic species with a minor ratio of males in natural habitats, but its male origin and sex determination mechanisms have been unknown. In this study, a male-biased mutant family was discovered from the gynogenetic gibel carp, and a male-specific SCAR marker was identified from the mutant family. Normal spermatogenesis was observed in the male testes by immuno. fluorescence histochemistry. Nearly identical AFLP profiles were observed between males and females, but a male-specific 86 bp AFLP fragment was screened by sex-pool bulked segregant analysis and individual screening. Based on the male-specific AFLP fragment, a total of 579 bp sequences were cloned by genome walking. Subsequently, a male-specific SCAR marker was designed, and the male-specific DNA fragment was confirmed to be steadily transmitted to the next generation and consistently detected only in males. (C) 2009 National Natural Science Foundation of China and Chinese Academy of Sciences. Published by Elsevier Limited and Science in China Press. All rights reserved.

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Grass carp hemorrhagic virus (GCHV)-induced gene 2 (Gig2) is a novel gene previously identified from UV-inactivated GCHV-treated Carassius auratus blastulae embryonic (CAB) cells, suggesting that it should play a pivotal role in the interferon (IFN) antiviral response. In this study, a polyclonal anti-Gig2 antiserum was generated and used to study the inductive expression pattern by Western blot analysis, showing no basal expression in normal CAB cells but a significant up-regulation upon UV-inactivated GCHV, polyinosinic:polycytidylic acid (Poly I:Q and recombinant IFN (rIFN). However, constitutive expression of Gig2 is observed in all tested tissues from grass carp (Ctenopharyngodon idellus), and Poly I:C injection increases the relative amount of Gig2 protein in skin, spleen, trunk kidney, gill, hindgut and thymus. Moreover, the genomic sequence covering the whole Gig2 ORF and the upstream promoter region were amplified by genomic walking. Significantly, the Gig2 promoter contains three IFN-stimulated response elements (ISREs), nine GAAA/TfTC motifs and five gamma-IFN activating sites (GAS), which are the characteristics of genes responsive to both type I IFN and type 11 IFN. Subsequently, the complete Gig2 promoter sequence was cloned into pGL3-Basic vector, and its activity was measured by luciferase assays in the transfected CAB cells. The Gig2 promoter-driven construct is highly induced in CAB cells after treatment with Poly I:C or rIFN, and the functional capability is dependent on IFN regulatory factor 7 (IRF7), because its activity can be stimulated by IRF7. Collectively, the data provide strong evidence that Gig2 is indeed a novel IFN inducible gene and its expression is likely dependent on IRF7 upon Poly I:C or IFN. (C) 2009 Elsevier Ltd. All rights reserved.

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By suppression subtractive hybridization, rapid amplification of cDNA ends and gene walking methods, interferon stimulated genes (ISGs), Viperin and ISG15, and their promoters have been cloned and characterized from snakehead Channa argus. The Viperin cDNA was found to be 1474 nt and contain an open reading frame (ORF) of 1059 nt that translates into a putative peptide of 352 amino acid (aa). The putative peptide of Viperin shows high identity to that in teleosts and mammals except for the N-terminal 70 aa. The ISG15 cDNA was found to be 758 nt and contain an ORF of 468 nt that translates into a putative peptide of 155 aa. The putative peptide of ISG15 is composed of two tandem repeats of ubiquitin-like (UBL) domains, and a canonical conjugation motif (LRGG) at C-terminal. Viperin and ISG15 promoter regions were characterized by the presence of interferon stimulating response elements (ISRE) and gamma-IFN activation sites (GAS). ISRE is a feature of IFN-induced gene promoter and partially overlaps interferon regulatory factor (IRF) 1 and IRF2 recognition sites. GAS is responsible for the gamma-IFN mediated transcription. One conserved site for NF-kappa B was found in the promoter region of Viperin. This is the first report of conservative binding motif for NF-kappa B in accordance with the consensus sequence (GGGRN-NYYCC) among teleost ISG promoters. Moreover, there were also TATA, CAAT and Sp1 transcription factor sites in Viperin and ISG15 promoters. In 5' untranslated region (UTR), snakehead ISG15 gene contains a single intron, which differs from Viperin gene. The transcripts of Vipeirn and ISG15 mRNA were mainly expressed in head kidney, posterior kidney, spleen and gill. The expression levels in liver were found to increase obviously in response to induction by IFN-inducer poly I : C.

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Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is one of the TNF superfamily members, participating in many biological processes including cell proliferation and apoptotic death. In this study, a TRAIL gene was cloned from a perciform fish, the mandarin fish Siniperca chuatsi, a major cultured fish in China's aquaculture, and is named as SCTRAIL for S. chuatsi TRAIL. The full-length cDNA of SCTRAIL is 1359 bp, encoding a 283-amino-acid protein. This deduced protein contains the CYS231, a 23-mer fragment of transmembrane region, a glycosylation site and a TNF family signature, all of which are conserved among TRAIL members. SCTRAIL gene consists of six exons, with five intervening introns, spaced over approximately 9 kb of genomic sequence. Southern blotting demonstrated that the SCTRAIL gene is present as a single copy in mandarin fish genome. A 620 bp promoter region obtained by genome walking contains a number of putative transcription factor binding sites, such as Oct-1, Sp-1, NF-1, RAP-1, C/EBPaLp, NF-kappa B and AP-1. The SCTRAIL is constitutively expressed in all the analyzed tissues, as revealed by RT-PCR, which is confirmed by Western blotting analysis using polyclonal antibody against bacteria-derived recombinant SCTRAIL protein. As an apoptosis-inducing ligand, the overexpression of SCTRAIL but not the mutant SCTRAIL-C203S in HeLa cells induced changes characteristic of apoptosis, including chromatin condensation, nucleus fragmentation, DNA ladder, and increase of sub-G0/G1 cells in FACS analysis. (c) 2007 Elsevier Ltd. All rights reserved.

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Some members of hairy/Enhancer-of-split-related gene (HES) family have important effects on axial mesoderm segmentation and the establishment and maintenance of the somite fringe. In fishes. the her6 gene, a member of the HES family, is the homologue Of heS1 in mammals and chicken. In this study, the her6 gene and its full-length cDNA from the common carp (Cyprinus carpio) were isolated and characterized. The genomic sequence of common carp her6 is approximately 1.7 kb. with four exons and three introns, and the full-length cDNA of 1314 bp encodes a Putative polypeptide of 271 amino acids. To analyse the promoter sequence of common carp her6. sequences of various lengths upstream from the transcription initiation site of her6 were fused to enhanced green fluorescent. protein gene (eGFP) and introduced into zebrafish embryos by microinjection to generate transgenic embryos. Our results show that the upstream sequence of 500 bp can direct highly efficient and tissue-specific expression of eGFP in zebrafish embryos. whereas a fragment of 200 bp containing the TATA box and a partial suppressor of hairless paired site sequence (SPS) is not sufficient to drive eGFP expression in zebrafish embryos.

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In order to identify genes encoding the outer membrane proteins (OMPs) of the myxobacter Flavobacterium columnare G(4), the expression library of the bacterium was screened by using rabbit antisera developed against its OMPs. Positive colonies of Escherichia coli M15 containing fragments encoding the bacterial OMPs were selected for cloning the relevant genes by genomic walking methods. Two genes encoding a membrane-associated zinc metalloprotease and prolyl oligopeptidase are reported in this paper. The membrane-associated zinc metalloprotease gene (map) is 1800 bp in length, coding for 449 amino acids (aa). Despite the presence of a conserved motif HEXXH for all metalloproteases, the special HEXXH similar to 32 aa similar to E motif of the F. columnare G(4) Map and its low level of identity with other reported zinc-containing metalloproteases may imply that the membrane-associated zinc metalloprotease of F. columnare G(4) represents a new family of zincins. The gene encoding prolyl oligopeptidase (Pop), a serine proteinase, is 2352 bp in length, coding for 649 aa. Sequence homology analysis revealed that the Pop is also novel as it has <50% identity with other reported prolyl oligopeptidase family proteins. The present study represents the first to employ anti-fish bacterial OMP sera to screen genes of membrane-associated proteases of fish pathogenic bacteria, and to provide necessary information for the examination of the role of the two genes in the infection and pathogenesis of F. columnare.

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We report on the design and fabrication of a photonic crystal (PC) channel drop filter based on an asymmetric silicon-on-insulator (SOI) slab. The filter is composed of two symmetric stick-shape micro-cavities between two single-line-defect (W1) waveguides in a triangular lattice, and the phase matching condition for the filter to improve the drop efficiency is satisfied by modifying the positions and radii of the air holes around the micro-cavities. A sample is then fabricated by using electron beam lithography (EBL) and inductively coupled plasma (ICP) etching processes. The measured 0 factor of the filter is about 1140, and the drop efficiency is estimated to be 73% +/- 5% by fitting the transmission spectrum.