检索结果-南通市图书馆

Evolution of metabolic scaling among the tetrapod:effect of phylogeny,the geologic time of class formation,and uniformity of species within a class

在线全文

学校读者我要写书评

暂无评论

Integrative Zoology 2022年第5期17卷 904-917页

作者： valery M.GAvRILOv Tatiana B.GOLUBEvA Andrey v.BUsHUEv Department of vertebrate Zoology M.V.Lomonosov Moscow State UniversityMoscowRussia Zvenigorod Biological station M.V.Lomonosov Moscow State UniversityMoscowRussia

The metabolic scaling in the animal has been discussed for over 90 years,but no consensus has been *** analysis of 2126 species of vertebrates reveals a signiﬁcant allometric exponent *** show that classes of terrestrial vertebrates exhibit the evolution of metabolic *** the allometric coefﬁcient“a”and the allometric exponent“b”change naturally,but differently depending on the geological time of group *** allometric coefﬁcient“a”shows the measure of the evolutionary development of systems that forms resting metabolism in *** classes,such as birds and mammals,have a metabolic rate that is in an order of magnitude higher than that in ectothermic classes,including amphibians and *** the terrestrial vertebrate phylogeny,weﬁnd that the metabolic scaling is characterized by 3 main allometric exponent values:b=3/4(mammals),b>3/4(ectotherms,such as amphibians and reptiles),and bs).The hetero-geneity of the allometric exponent is a natural phenomenon associated with the general evolution of *** scaling factor decreases depending on both the external design and the size(birds vs mammals)of the *** metabolic rate and uniformity of species within a class increase as the geological start date of for-mation of the class approaches the present *** higher the mass-speciﬁc standard metabolic rate in the class,the slower metabolic rate grows with increasing body size in this *** results lay the groundwork for further exploration of the evolutionary and ecological aspects of the development of metabolic scaling in animals.

关键词： geological time metabolic rate scaling

Gas tungsten arc welding of ZrB_2-siC based ultra high temperature ceramic composites

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2015年第3期11卷 188-196页

作者： R.v.KRIsHNARAO G.MADHUsUDHAN REDDY Defence Metallurgical Research Laboratory

The difficulty in fabricating the large size or complex shape limits the application of ZrB2-siC composites. Joining them by fusion welding without or with preheating, controlled cooling under protective gas shield leads to thermal shock failure or porosity at the weld interface. In the present work, a filler material of(ZrB2-siC-B4C-YAG) composite with oxidation resistance and thermal shock resistance was produced in the form of welding wire. Using the filler, gas tungsten arc welding(GTAW) was performed without employing preheating, post controlled cooling and extraneous protective gas shield to join hot pressed ZrB2-siC(Zs), and pressureless sintered ZrB2-siC-B4C-YAG(ZsBY) composites to themselves. The fusion welding resulted in cracking and non-uniform joining without any filler material. The weld interfaces of the composites were very clean and coherent. The vickers micro-hardness across the weld interface was found to increase due to the increase in the volume % of both siC and B4C in the filler material. The shear strength of the weld was about 50% of the flextural strength of the parent composite.

关键词：陶瓷基复合材料焊接界面钨极氩弧焊气体保护超高温填充材料 ZrB2 形状复杂

Improving the Quality of Thermocouple Wire Made of Platinum-rhodium Alloys

在线全文

学校读者我要写书评

暂无评论

贵金属 2012年第A1期33卷 102-103页

作者： HORIKOv P. A. MAMONOv s. N. EFIMOv v. N. RADKIN A. N. DROZDOv D. E. JsC "Krastsvetmet" Krasnoyarsk Russia

For the manufacture of s-type thermocouple the so-called thermocouple wire of platinum and platinum-rhodium alloy is *** of the main technical requirements for the quality of the wire,according to state standard of Russia(GOsT 10821),is the uniformity of its largest thermoelectric force(Thermo-emf) in the length different *** was found that a determining impact on the uniformity of the wire thermo-emf is the distribution of rhodium along the length of the *** impact of platinum-rhodium melt crystallization conditions on the inhomogeneity of wire manufactured from *** was suggested that the chemical inhomogeneity of the wire is related to the liquation phase of platinum-rhodium alloy.

关键词： thermocouple thermocouple wire platinum-rhodium alloy inhomogeneity crystallization liquation phase

Quantitative Mobility spectrum Analysis for Determination of Electron and Magneto Transport Properties of Te-Doped Gasb

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2005年第9期22卷 2363-2366页

作者： s. Acar M. Kasap B. Y. Isik s. Oezcelik N. Tugluoglu s. Karadeniz Department of Physics Faculty of Science and Arts University of Gazi Teknikokullar 06500 Ankara Turkey Department of Materials Research Ankara Nuclear Research and Training Center 06100 Besevler Ankara Turkey

Resistivity, magnetoresistivity and Hall effect measurements in n-type Te-doped Gasb grown by the liquid encapsuled Czochralski technique are carried out as functions of temperature （35-350 K） and magnetic field （0-1.35 T）. The power law model is used to explain the temperature-dependent resistivity. The magnetic-field-dependent data are analysed using the quantitative mobility spectrum analysis technique. The effect of individual band parameters （nL, nr, μL, μr, p and μp） on both the electron and magneto transports have been discussed. The EL - Er energy separation between the L and conduction band edges is also derived.

关键词： N-TYPE GAsB GALLIUM ANTIMONIDE MAGNETOTRANsPORT CHARACTERIZATION CONDUCTION-BAND HALL MAGNETOREsIsTANCE DEPENDENCE

smart Grid Communication Under Elliptic Curve Cryptography

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Intelligent Automation & soft Computing 2023年第5期36卷 2333-2347页

作者： B.Prabakaran T.R.sumithira v.Nagaraj Mahendra Engineering College Salem637503TamilnaduIndia Government College of Engineering Salem636011TamilnaduIndia Knowledge Institute of Technology Salem637504TamilnaduIndia

smart Grids(sGs)are introduced as a solution for standard power *** signiﬁcant capabilities of smart grids help to monitor consumer behaviors and power ***,the delay-sensitive network faces numer-ous challenges in which security and privacy gain more *** to trans-mitted messages,control over smart grid information and user privacy are the major concerns in smart grid *** secure communication between the service provider and the user is the only possible solution for these security ***,this research work presents an efﬁcient mutual authentication and key agreement protocol for smart grid communication using elliptic curve crypto-graphy which is robust against security threats.A trust authority module is intro-duced in the security model apart from the user and service provider for *** proposed approach performance is veriﬁed based on different security features,communication costs,and computation *** comparative analysis of experimental results demonstrates that the proposed authentication model attains better performance than existing state of art of techniques.

关键词： smart grid elliptic curve cryptography key management mutual authentication

The Plant Cell surface

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2010年第2期52卷 126-130页

作者： Anne-Mie C. Emons Kurt v. Fagerstedt The Editor of this special Issue Plant Cell Biology Droevendaalsesteeg 1 Wageningen University 6708 PB Wageningen The Netherlands The Editor of this special Issue Plant Biology PO Box 65 FI-00014 Helsinki University Finland

Multicellular organization and tissue construction has evolved along essentially different lines in plants and animals. since plants do not run away, but are anchored in the soil, their tissues are more or less firm and stiff. This strength stems from the cell walls, which encase the fragile cytoplasm, and protect it. Properties of plant cell walls translate into properties of plant tissue. For instance, the cellulose microfibril angle in the different layers of walls of individual cells is a determinant of mechanical functions, which are useful to the plant itself. It also determines material properties of tissues and their potential industrial use. Indeed, plant cell walls determine the industrial value of a range of plant products including paper, timber, foodstuff, fodder, spun fibers, coatings, renewable polymers and future nanocomposites. Cell walls and their biosynthesis is a very active field of plant research.

关键词： cell The Plant Cell surface

An experimental investigation of wire electrical discharge machining of hot-pressed boron carbide

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2015年第4期11卷 344-349页

作者： Ravindranadh BOBBILI v.MADHU A.K.GOGIA Defence Metallurgical Research Laboratory

The present work discusses the experimental study on wire-cut electric discharge machining of hot-pressed boron *** effects of machining parameters,such as pulse on time(TON),peak current(IP),flushing pressure(FP) and spark voltage on material removal rate(MRR)and surface roughness(R_a) of the material,have been *** parameters are found to have an effect on the surface integrity of boron carbide machined *** rate of brass wire increases with rise in input energy in machining of hot-pressed boron *** surfaces of machined samples were examined using scanning electron microscopy(sEM).The influence of machining parameters on mechanism of MRR and R_a was *** was demonstrated that higher TON and peak current deteriorate the surface finish of boron carbide samples and result in the formation of large craters,debris and micro *** generation of spherical particles was noticed and it was attributed to surface tension of molten ***-ridges were also observed on the surface due to protrusion of molten material at higher discharge energy levels.

关键词：电火花加工碳化硼热压制实验扫描电子显微镜材料去除率表面粗糙度电火花线切割

search for Compromise solution of the MultistageAxial Compressor's stochastic Optimization Problem

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal science 1998年第4期7卷 218-225页

作者： I.N.Egorov G.v.Kretinin AirForecEngineeringAcademy LeningradskyAv.40.MoscowRussia AirForecEngineeringAcademy LeningradskyAv

The aim of this paper is to discuss a method of the compromise region determination for the multistage axial flow compressor stochastic optimization problems. This method is based on the 2-D axisynunetrical mathematical model of the compressor and on the new multicriteria optimization procedure.A specific feature of the multicriteria optimization procedure is a possibility to obtain a set of the Edgeworth-Pareto optimal solutions within the frame of single optimization task. The paper presents some examples of the compressor’s geometrical parameters multicriteria optimization.

关键词： multicriteria stochastic optimization multistage axial flow compressor

Comparative Analysis of Protein-Protein Interactions in Cancer-Associated Genes

在线全文

学校读者我要写书评

暂无评论

Genomics, Proteomics & Bioinformatics 2009年第1期7卷 25-36页

作者： Purnima Guda sridar v. Chittur Chittibabu Guda GenNYsis Center for Excellence in Cancer Genomics and Department of Epidemiology & Biostatistics State University of New York at AlbanyRensselaer NY 12144-3456 USA Center for Functional Genomics and Department of Biomedical sciences State University of New York at AlbanyRensselaer NY 12144-3456 USA

Protein-protein interactions （PPIs） have been widely studied to understand the biological processes or molecular functions associated with different disease systems like cancer. While focused studies on individual cancers have generated valuable information, global and comparative analysis of datasets from different cancer types has not been done. In this work, we carried out bioinformatic analysis of PPIs corresponding to differentially expressed genes from microarrays of various tumor tissues （belonging to bladder, colon, kidney and thyroid cancers） and compared their associated biological processes and molecular functions （based on Gene Ontology terms）. We identified a set of processes or functions that are common to all these cancers, as well as those that are specific to only one or partial cancer types. similarly, protein interaction networks in nucleic acid metabolism were compared to identify the common/specific clusters of proteins across different cancer types. Our results provide a basis for further experimental investigations to study protein interaction networks associated with cancer. The methodology developed in this work can also be applied to study similar disease systems.

关键词： protein-protein interaction,cancer-associated genes GO similarity analysis cancer bioinformatics