检索结果-南通市图书馆

Quasi-static simulations of compact polydisperse particle systems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2010年第2期8卷 119-126页

作者： colin Thornton School of Civil Engineering University of Birmingham Birmingham UK

The Discrete Element Method （DEM） was originally devised by Cundail and Strack （1979）, as a technique to examine the micromechanics of granular media with the anticipation that this would lead to more physically reliable continuum theories to describe the quasi-static deformation of granular material such as sand. However, the methodology models the evolution of a system of particles as a dynamic process. Consequently there have been numerous publications of the application of DEM to an increasingly wider variety of problems in many areas of engineering and science. This paper, however, focuses on the orig- inal motivation for DEM and attempts to provide a state-of-the-art understanding of the quasi-static deformation of granular media. 2009 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier b.V. All rights reserved.

关键词： Discrete Element MethodQuasi-static deformationGranular media

Eventual Positivity of Hermitian Polynomials and Integral Operators

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series b 2016年第1期37卷 83-94页

作者： colin TAN Department of Mathematics National University of Singapore Block S17 10 Lower Kent Ridge Road Singapore 119076.

Quillen proved that if a Hermitian bihomogeneous polynomial is strictly positive on the unit sphere, then repeated multiplication of the standard sesquilinear form to this polynomial eventually results in a sum of Hermitian squares. Catlin-D'Angelo and Varolin deduced this positivstellensatz of Quillen from the eventual positive-definiteness of an associated integral operator. Their arguments involve asymptotic expansions of the bergman kernel. The goal of this article is to give an elementary proof of the positive-definiteness of this integral operator.

关键词： Asymptotics Polynomial Positivity

T-DNA-Induced Chromosomal Translocations in feronia and anxur2 Mutants Reveal Implications for the Mechanism of Collapsed Pollen Due to Chromosomal Rearrangements

在线全文

学校读者我要写书评

暂无评论

Molecular Plant 2014年第10期7卷 1591-1594页

作者： colin Ruprecht[a],, Andrew Carroll[b] Staffan Persson[a],[c], a Max-Planck-Institute for Molecular Plant Physiology Am Muehlenberg 1 14476 Potsdam Germanyb Department of Biology Stanford University Stanford CA 94305 USAc ARC Centre of Excellence in Plant Cell Walls School of Botany University of Melbourne Parkville 3010 Victoria Australia

Dear Editor, Approximately every fifth Arabidopsis T-DNA inser- tion line contains chromosomal translocations caused by the inserted T-DNA （Clark and Krysan, 2010）. Albeit broad use of T-DNA lines for mutant analysis, little is known about the consequences of these chromosomal rearrangements and only a few studies describe chromosomal aberrations in the mutant lines. While plant growth in general is not affected by such chromosomal translocations, defects in gametophyte development have been observed in lines that are heterozygous for the T-DNA insertion （Ray et al., 1997; Curtis et al., 2009）.

关键词： T-DNA插入染色体易位染色体重排突变系体显示苹果属机制花粉

Efficient and Stereoselective Synthesis of C-(β-2'-Deoxynucleosides)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

有机化学 2004年第Z1期24卷 27-28页

作者： WU,Qin-Pei REES,b.colin School of Life Science Beijing Institute of Technology Beijing 100081 King''s College London WC2R 2LS UK

　　The formation of triplex DNA is, in principle, an effective way of regulating the expression of selected genes.[1]Many cytosine mimics were investigated to form triplex DNA, e.g., 2-amino-(2'-deoxy-β-D-ribofuranosyl)pyridine (9)was proved to have some effectiveness in stabilizing triplex DNA under neutral conditions.[2] Stereoselective synthesis of 9 was achieved starting from 2-deoxyribose.……

关键词： triplex DNA

Eventual Positivity of Hermitian Algebraic Functions and Associated Integral Operators

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 Annals of Mathematics,Series b 2020年第6期41卷 967-988页

作者： colin TAN Wing-Keung TO Department of Statistics&Applied Probability National University of Singapore Current address:Science Mat hematics and TechnologySingapore University of Technology and Design8 Somapah RoadSingapore 487372 Department of Mathematics National University of SingaporeBlock S1710 Lower Kent Ridge RoadSingapore 119076

Quillen proved that repeated multiplication of the standard sesquilinear form to a positive Hermitian bihomogeneous polynomial eventually results in a sum of Hermitian squares,which was the first Hermitian analogue of Hilbert s seventeenth problem in the nondegenerate *** Catlin-D’Angelo generalized this positivstellensatz of Quillen to the case of Hermitian algebraic functions on holomorphic line bundles over compact complex manifolds by proving the eventual positivity of an associated integral *** arguments of Catlin-D’Angelo involve subtle asymptotic estimates of the bergman *** this article,the authors give an elementary and geometric proof of the eventual positivity of this integral operator,thereby yielding another proof of the corresponding positivstellensatz.

关键词： Hermitian algebraic functions Integral operators Positivity

Homological behavior of idempotent subalgebras and Ext algebras

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2020年第2期63卷 309-320页

作者： colin Ingalls Charles Paquette School of Mathematics and Statistics Carleton UniversityOttawaON K1S 5E6Canada Department of Mathematics and Computer Science Royal Military College of CanadaKingstonON K7K 7B4Canada

Let A be a(left and right) Noetherian ring that is semiperfect. Let e be an idempotent of A and consider the ring Γ :=(1-e)A(1-e) and the semi-simple right A-module Se := e A/e rad A. In this paper, we investigate the relationship between the global dimensions of A and Γ, by using the homological properties of Se. More precisely, we consider the Yoneda ring Y(e) := Ext_A~*(Se, Se) of e. We prove that if Y(e) is Artinian of finite global dimension, then A has finite global dimension if and only if so does Γ. We also investigate the situation where both A and Γ have finite global dimension. When A is Koszul and finite dimensional, this implies that Y(e) has finite global dimension. We end the paper with a reduction technique to compute the Cartan determinant of Artin algebras. We prove that if Y(e) has finite global dimension, then the Cartan determinants of A and Γ coincide. This provides a new way to approach the long-standing Cartan determinant conjecture.

关键词： global dimension Noetherian ring semiperfect ring idempotent subalgebra Cartan determinant

Chemical-assisted MMP reduction on methane-oil systems:Implications for natural gas injection to enhanced oil recovery

在线全文

学校读者我要写书评

暂无评论

Petroleum 2024年第1期10卷 101-108页

作者： Mohamed Almobarak Matthew b.Myers colin D.Wood Yongbing Liu Ali Saeedi Quan Xie Discipline of Petroleum Engineering WA School of Mines:MineralsEnergy and Chemical EngineeringCurtin UniversityWestern AustraliaAustralia Commonwealth Scientific and Industrial Research Organization Kensington6151Australia Curtin University Oil and Gas Innovation Centre Management Kensington6151Australia State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation No.8 Xindu AvenueXindu DistrictChengdu 610500PR China

***,the main challenge in this process is the high minimum miscibility pressure(MMP)between natural gas and crude oil,which limits its application and recovery factor,especially in hightemperature ***,we present a novel investigation to quantify the effect of chemicalassisted MMP reduction on the oil recovery ***,we measured the interfacial tension(IFT)of the methane-oil system in the presence of chemical or CO_(2) to calculate the MMP reduction at a constant temperature(373K)using the vanishing interfacial tension(VIT)***,we performed three coreflooding experiments to quantify the effect of MMP reduction on the oil recovery factor under different injection *** interfacial tension measurements show that adding a small fraction(1.5 wt%)of the tested surfactant(SOLOTERRA ME-6)achieved 9%of MMP reduction,while adding 20 wt%of CO_(2) to the methane yields 13%of MMP ***,the coreflooding results highlight the significance of achieving miscibility during gas injection,as the ultimate recovery factor increased from 65.5%under immiscible conditions to 77.2%using chemical-assisted methane,and to 79%using gas mixture after achieving near miscible *** results demonstrate the promising potential of the MMP reduction to signifi-cantly increase the oil recovery factor during gas ***,these results will likely expand the application envelop of the miscible gas injection,in addition to the environmental benefits of utilizing the produced gas by re-injection/recycling instead of flaring which contributes to reducing the greenhouse gas emissions.

关键词： Gas injection Enhanced oil recovery Miscibility Coreflooding

Corticospinal activity during a single-leg stance in people with chronic ankle instability

在线全文

学校读者我要写书评

暂无评论

Journal of Sport and Health Science 2022年第1期11卷 58-66页

作者： Masafumi Terada Kyle b.Kosik Ryan S.McCann colin Drinkard Phillip A.Gribble College of Sport and Health Science Ritsumeikan UniversityKusatsuShiga 525-8577Japan Department of Athletic Training&Clinical Nutrition University of KentuckyLexingtonKY 40536-0200USA School of Rehabilitation Sciences Old Dominion UniversityNorfolkVA 23529USA Westlake High School Athletics AustinTX 78746USA

Purpose:The aim of the study was to determine whether corticospinal excitability and inhibition of the tibialis anterior during single-leg standing differs among individuals with chronic ankle instability(CAI),lateral ankle sprain copers,and healthy ***:Twenty-three participants with CAI,23 lateral ankle sprain copers,and 24 healthy control participants *** motor threshold(AMT),normalized motor-evoked potential(MEP),and cortical silent period(CSP)were evaluated by transcranial magnetic stimulation while participants performed a single-leg standing ***:Participants with CAI had significantly longer CSP at 100%of AMT and lower normalized MEP at 120%of AMT compared to lateral ankle sprain copers(CSP100%:p=0.003;MEP120%:p=0.044)and controls(CSP100%:p=0.041;MEP120%:p=0.006).Conclusion:This investigation demonstrate altered corticospinal excitability and inhibition of the tibialis anterior during single-leg standing in participants with *** research is needed to examine the effects of corticospinal maladaptations to motor control of the tibial anterior on postural control performance in those with CAI.

关键词： Ankle sprain Joint instability Motor cortex Postural control

Protein-based profiling of the human IgA1 clonal repertoire revealed shared clones of serum polymeric IgA1 and milk secretory IgA1

在线全文

学校读者我要写书评

暂无评论

Cellular & Molecular Immunology 2023年第3期20卷 305-307页

作者： Jan Novak Matthew b.Renfrow R.Glenn King colin Reily Todd J.Green Department of Microbiology University of Alabama at BirminghamBirminghamALUSA Department of biochemistry and Molecular Genetics University of Alabama at BirminghamBirminghamALUSA

Human adaptive immunity involves the production and secretion of antibodies by differentiated b cells(ie.,antibody-secreting cells,also called plasma cells)in response to *** secreted antigen-specific antibodies are immunoglobulins that are present at substantial concentrations in blood,mucosal secretions,and breast ***,human immunoglobulins consist of two identical heavy(H)chains and two identical light(L)chains that are connected by disulfide bridges to form a homodimer of heterodimers(ie.,H+Ll2).Each heterodimer consists of one H chain linked with one L chain,whereas the homodimer is formed by linking two H chains *** genes for both the L and H chains are encoded by ligated gene segments that are genetically rearranged during V(D)J recombination,a process that endows each b cell with a unique receptor,giving rise to the enormous diversity of the b-cell antigen receptor repertoire.

关键词： IgA1 immunity chains