检索结果-南通市图书馆

Secondary neurogenesis and telencephalic organization in zebrafish and mice: a brief review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Integrative Zoology 2009年第1期4卷 123-133页

作者： Mario f.WULLIMANN Department of Biology II Ludwig-Maximilians-UniversityMunich-MartinsriedGermany

Most zebrafish neurodevelopmental studies have focused on the embryo,which is characterized by primary neurogenesis of mostly transient *** neurogenesis becomes dominant in the hatching larva,when major brain parts are established and begin to *** developmental period allows for a comparative analysis of zebrafish brain organization with amniotes at equivalent stages of *** a particular time window,the early forebrains of mice(Embyronic stage[E]12.5/13.5 days[d])and zebrafish(3 d)reveal highly comparable expression patterns of genes involved in neurogenesis,for example proneural and other transcription factors(Neurogenin1,NeuroD,Mash1/Zash1a and Pax6).further topological correspondences are seen in the expression of LIM and homeobox genes,such as Lhx6/7,Tbr2 and *** this analysis is extended to gamma-aminobutyric acid/glutamic acid decarboxylase(GABA/GAD)cell patterns during this critical time window,an astonishing degree of similarity between the two species is again seen,for example regarding the presence of GABA/GAD cells in the subpallium,with the pallium only starting to be invaded by such cells from the ***,the expression of proneural and other genes correlates with GABA cell patterns(***1/Zash1a gene expression in GABA-positive and Neurogenin1/NeuroD in GABA-negative telencephalic regions)in mice and *** from additional vertebrates,such as Xenopus,are also highly consistent with this ***,the vertebrate forebrain appears to undergo a phylotypic stage of secondary neurogenesis,characterized by regionally separated GABAergic(inhibitory)versus glutamatergic(excitatory)cell production sites,which are obscured later in development by tangential *** period is highly advantageous for molecular neuroanatomical cross-species comparisons.

关键词： basal ganglia cortex subpallium tangential migration gamma-aminobutyric acid GABA.

function of seminal vesicles and their role on male fertility

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2001年第4期3卷 251-258页

作者： Gustavo f.Gonzales Department of Physiological Sciences Faculty of Sciences and Philosophy and Instituto de Invertigaciones de la Altura Universidad Peruana Cayetano Heredia Lima Peru

The present review has been designed to update the recent developments on the function of seminal vesicles andtheir role on male fertility. It is indicated that the true corrected fructose level is a simple method for the assessment ofthe seminal vesicular function. Measurement of seminal fructose used universally as a marker of the seminal vesiclefunction is not an appropriate approach due to its inverse relationship with the sperm count. The true corrected fructosedefined as [log. motile sperm concentration] multiplied by [seminal fructose concentration] has been shown to be abetter marker of the seminal vesicle function. Seminal vesicular secretion is important for semen coagulation, sperm motility, and stability of sperm chromatinand suppression of the immune activity in the female reproductive tract. In conclusion, the function of seminal vesicle is important for fertility. Parameters as sperm motility, sperm chro-matin stability, and immuno-protection may be changed in case of its hypofunction. (Asian J Androl 2001 Dec; 3:251 -258)

关键词： seminal vesicles male fertility male infertility true corrected fructose

Varieties for Cohomology with Twisted Coefficients

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 1999年第1期15卷 81-92页

作者： Jon f.Carlson Department of Mathemtics University of GeorgiaAthensGA 30602 USA

Let G be a finite group and k a field of characteristic p>*** this paper we consider the support variety for the cohomology module ExtkG*（M,N） where M and N are *** is the subvariety of the maximal ideal spectrum of H*（G,k） of the annihilator of the cohomology module. for modules in the principal block we show that that the variety is contained in the intersections of the varieties of M and N and the difference between the that intersection and the support variety of the cohomology module is contained in the group theoretic *** other blocks a new nucleus is defined and a similar theorem is *** in the case of modules in a nonprincipal block several new difficulties are highlighted by some examples.

关键词： Group Cohomology Support varieties Cohomological varieties Annihilators of cohomology

Numerical Study of flow and Gas Diffusion in the Near-Wake behind an Isolated Building

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2009年第6期26卷 1241-1252页

作者： Mohamed f.YASSIN Department of Environmental Technology Management College for WomenKuwait University P.O.Box 5969KuwaitSafat 13060Kuwait faculty of Engineering Assiut UniversityAssiut-71516Egypt

To assist validation of the experimental data of urban pollution dispersion, the effect of an isolated building on the flow and gaseous diffusion in the wake region have been investigated numerically in the neutrally stratified rough-walled turbulent boundary layer. Numerical studies were carried out using Computational fluid Dynamics （CfD） models. The CfD models used for the simulation were based on the steady-state Reynolds-Average Navier-Stoke equations （RANS） with κ-ε turbulence models; standard κ-ε and RNG κ-ε models. Inlet conditions and boundary conditions were specified numerically to the best information available for each fluid modeling simulation. A gas pollutant was emitted from a point source within the recirculation cavity behind the building model. The accuracy of these simulations was examined by comparing the predicted results with wind tunnel experimental data. It was confirmed that simulation using the model accurately reproduces the velocity and concentration diffusion fields with a fine-mish resolution in the near wake region. Results indicated that there is a good agreement between the numerical simulation and the wind tunnel experiment for both wind flow and concentration diffusion. The results of this work can help to improve the understanding of mechanisms of and simulation of pollutant transport in an urban environment.

关键词： atmospheric turbulence CfD model isolated building pollutant dispersion

A Model Transformation Approach for Detecting Distancing Violations in Weighted Graphs

在线全文

学校读者我要写书评

暂无评论

Computer Systems Science & Engineering 2021年第1期36卷 13-39页

作者： Ahmad f.Subahi Department of Computer Science University College of Al JamoumUmm Al Qura UniversityMakkah21421Saudi Arabia

This work presents the design of an Internet of Things(IoT)edge-based system based on model transformation and complete weighted graph to detect violations of social distancing measures in indoor public *** sensor network based on Bluetooth Low Energy is introduced as the infrastructure of the proposed design.A hybrid model transformation strategy for generating a graph database to represent groups of people is presented as a core middleware layer of the detecting system’s proposed architectural design.A Neo4j graph database is used as a target implementation generated from the proposed transformational system to store all captured real-time IoT data about the distances between individuals in an indoor area and answer user predefined queries,expressed using Neo4j Cypher,to provide insights from the stored data for decision *** proof of concept,a discrete-time simulation model was adopted for the design of a COVID-19 physical distancing measures case study to evaluate the introduced system ***-one weighted graphs were generated randomly and the degrees of violation of distancing measures were *** experimental results demonstrate the capability of the proposed system design to detect violations of COVID-19 physical distancing measures within an enclosed area.

关键词： Model-driven engineering(MDE) Internet-of-Things(IoTs) model transformation edge computing system design Neo4j graph databases

Improving weld formability by a novel dual-rotation bobbin tool friction stir welding

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 Materials Science & Technology 2018年第1期34卷 135-139页

作者： f.f.Wang W.Y.Li J.Shen Q.Wen J.f.dos Santos State Key Laboratory of Solidification Processing Shaanxi Key Laboratory of Friction Welding Technologies Northwestern Polytechnical University Helmholtz-Zentrum Geesthacht Institute of Materials Research Materials Mechanics China Academy of Launch Vehicle Technology Beijing Institute of Astronautical Systems Engineering

A novel dual-rotation bobbin tool friction stir welding （DBT-fSW） was developed, in which the upper shoulder （US） and lower shoulder （LS） have different rotational speeds. This process was tried to weld 3.2 mm thick alunlinum-lithium alloy sheets. The metallographic analysis and torque measurement were carried out to characterize the weld formabiliW. Experimental results show that compared to conven- tional bobbin tool friction stir welding, the DBT-fSW has an excellent process stability, and can produce the defect-free joints in a wider range of welding parameters. These can be attributed to the significant improvement of material flow caused by the formation of a staggered layer structure and the unbalanced force between the US and LS during the DBT-fSW process.

关键词： Bobbin tool friction stir welding Dual rotation Material flow Microstructure Microhardness

first Detailed Photometric Investigation on the Nature of Contact Binary System AA Cet

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2023年第7期23卷 154-163页

作者： M.f.Yıldırım f.Soydugan Çanakkale Onsekiz Mart University Astrophysics Research Center and Ulupınar Observatory17020ÇanakkaleTurkey Çanakkale Onsekiz Mart University Faculty of SciencesDepartment of Physics17020ÇanakkaleTurkey

The TESS light curve(LC)of the marginal contact binary A A Cet was analyzed simultaneously with the radial velocity and the orbital period(OP)change of the system was *** physical parameters of the system were obtained by analyzing the LC of A A Cet with the Wilson-Devinney method,and the absolute parameters of the components were calculated using the results *** the components of AA Cet,the masses and radii were calculated as M_(1)=1.39±0.04 M_⊙,M_(2)=0.48±0.02 M_⊙,and R_(1)=1.64±0.03 R_⊙,R_(2)=1.01±0.04 R_⊙,*** Cet is a marginal contact binary with a temperature difference of 1305 K between its components.A total of 14 eclipse times were obtained from the TESS data and used in the OP analysis together with those collected from the *** has been observed that the change in the OP of AA Cet is in the form of a decreasing *** mass transfer between the components has been interpreted as the reason for this *** OP decrease amount of A A Cet was obtained as dP/dt=0.0062±0.0006 s yr^(-1).and the reason for this decrease was attributed to a 3.3(9)×10^(-8)M_⊙.mass transfer per year from the more massive component to the less massive *** age of A A Cet has been estimated as 7 Gyr,as the age of contact systems helps us to understand their evolution.

关键词： (stars:)binaries:eclipsing stars:fundamental parameters stars:individual(AA Cet)

Precise correction to parameter ρ in the littlest Higgs model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics C 2008年第2期32卷 100-103页

作者： farshid Tabbakh f. farnoudi School of Nuclear Science Institute of Nuclear Science and Technology Atomic Energy Organization of Iran Northern Kargar Av. Tehran Iran

In this paper tree-level violation of weak isospin parameter, ρ in the frame of the littlest Higgs model is studied. The potentially large deviation from the standard model prediction for the ρ in terms of the littlest Higgs model parameters is calculated. The maximum value for ρ for f =1 TeV, c = 0.05, c＇ = 0.05 and v＇ = 1.5 GeV is ρ = 1.2973 which means a large enhancement than the SM.

关键词： the littlest Higgs model custodial symmetry violation

Application of asymptotic iteration method to a deformed well problem

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2016年第3期25卷 40-44页

作者： Hakan Ciftci H f Kisoglu Gazi Universitesi Fen FakultesiFizik Bolumu 06500 Teknikokullar AnkaraTurkiye Maritime faculty Department of Basic SciencesMersin UniversityMersinTurkey

The asymptotic iteration method （AIM） is used to obtain the quasi-exact solutions of the Schr6dinger equation with a deformed well potential. for arbitrary potential parameters, a numerical aspect of AIM is also applied to obtain highly accurate energy eigenvalues. Additionally, the perturbation expansion, based on the AIM approach, is utilized to obtain simple analytic expressions for the energy eigenvalues.

关键词： asymptotic iteration method quasi-exact solutions perturbation method approximate solutions