检索结果-南通市图书馆

Reiterated homogenization of a laminate with imperfect contact:gain-enhancement of effective properties

Applied Mathematics and Mechanics(english edition) 2018年第8期39卷 1119-1146页

作者： f.e.alvarez-borges J.BRAVO-CASTILLeRO M.e.CRUZ R.GUINOVART-DIAZ L.D.PeReZ-feRNANDeZ R.RODRIGUeZ-RAMOS f.J.SABINA facultad de Matematica y Computacion Departamento de MatematicaUniversidad de La HabanaSan Lazaro y LHabana 4La HabanaCP 10400Cuba Departamento de Matematicas y Mecanica Universidad Nacional Autonoma de MexicoInstituto de Investigaciones en Matematicas Aplicadas y en Sistemas01000 CDMXAP 20-126M′exico Departamento de engenharia Mecanica Universidade Federal do Rio de JaneiroPolitecnica/COPPECaixa Postal 68503Rio de JaneiroRJCEP 21941-972Brasil Departamento de Matematica e estatistica Universidade Federal de PelotasCaixa Postal 354PelotasRio Grande do SulCEP 96010-900Brasil

A family of one-dimensional(1D) elliptic boundary-value problems with periodic and rapidly-oscillating piecewise-smooth coefficients is considered. The coefficients depend on the local or fast variables corresponding to two different structural scales. A finite number of imperfect contact conditions are analyzed at each of the scales. The reiterated homogenization method(RHM) is used to construct a formal asymptotic solution. The homogenized problem, the local problems, and the corresponding effective coefficients are obtained. A variational formulation is derived to obtain an estimate to prove the proximity between the solutions of the original problem and the homogenized problem. Numerical computations are used to illustrate both the convergence of the solutions and the gain of the effective properties of a three-scale heterogeneous 1D laminate with respect to their two-scale counterparts. The theoretical and practical ideas exposed here could be used to mathematically model multidimensional problems involving multiscale composite materials with imperfect contact at the interfaces.

关键词： reiterated homogenization method(RHM) imperfect contact variational formulation effective coefficient gain

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Merging bound states in the continuum in an open acoustic resonator

引用

Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 124-131页

作者： Lujun Huang Bin Jia Artem S.Pilipchuk Sibo Huang Chen Shen Almas f.Sadreev Yong Li Andrey e.Miroshnichenko School of Physics and electronic Sciences East China Normal University Institute of Acoustics Tongji University L.V.Kirensky Institute of Physics Department of Mechanical engineering Rowan University School of engineering and Technology University of New South Wales at Canberra

Bound states in the continuum （BICs） are perfectly localized resonances despite embedding in the continuum ***,an isolated BIC is very sensitive to the structure ***,we report merging acoustic BICs in a single open resonator,robust against the structure *** find that both symmetry-protected BIC and friedrich-Wintgen BIC are sustained in a single coupled waveguide-resonator *** varying the height and length of the resonator,these two BICs move toward each other and merge into a single one at a critical *** to an individual BIC,the merged BIC is robust against fabrication error because its Q-factor is proportional to ΔL-4,whereΔL embodies the structure *** essence of this extraordinary phenomenon is perfectly explained by the two-and three-level approximations of the effective nonHermitian ***,we present direct experimental demonstrations of the moving and merging of BICs in a coupled 3D waveguide-resonator,which are evidenced by the vanishing of the linewidth of fano resonance in the transmission *** results may find exciting applications in designing high-quality acoustic sources,sensors and filters.

关键词： acoustic resonances bound state in the continuum high-Q resonances

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Tales of the Tail and Sperm Head Aches --Changing concepts on the prognostic significance of sperm pathologies affecting the head, neck and tail

引用

Asian Journal of Andrology 2012年第1期14卷 14-23,174页

作者： Hector e Chemes Cristian alvarez Sedo Laboratory of Testicular Physiology and Pathology Center for Research in Endocrinology National Research Council （CONICET） Endocrinology Division Buenos Aires Children＇s Hospital Gallo 1330 C1425SEFD Buenos Aires Argentina Centro de estudios en Ginecologia y Reproduccion （CeGyR） C1425SEFD Buenos Aires Argentina

This article presents an update on the variable prognostic significance of different sperm pathologies in patients with severe male factor infertility due to morphology and motility disorders. Severe asthenozoospermia is one of the leading causes of male infertility as spermatozoa cannot reach the oocyte and/or penetrate normally. Identifying structural causes of sperm immotility was of great concern before the advent of intracytoplasmic sperm injection （ICSI）, because immotility was the limiting factor in the treatment of these patients. In these cases, in vitro methods are used to identify live spermatozoa or stimulate sperm motility to avoid selection of non-viable cells. With these advances, fertilization and pregnancy results have improved dramatically. The identification of genetic phenotypes in asthenozoospermia is important to adequately inform patients of treatment outcomes and risks. The one sperm characteristic that seriously affects fertility prognosis is teratozoospermia, primarily sperm head and neck anomalies. Defects of chromatin condensation and acrosomal hypoplasia are the two most common abnormalities in severe teratozoospermia. The introduction of microscopic methods to select spermatozoa and the development of new ones to evaluate sperm quality before ICSI will assure that ultrastructural identification ofsperm pathologies will not only be of academic interest, but will also be an essential tool to inform treatment choice. Herein, we review the differential roles played by sperm components in normal fertilization and early embryo development and explore how assisted reproductive technologies have modified our concepts on the prognostic significance of sperm pathologies affecting the head, neck, mid-piece and tail.

关键词： acrosomal hypoplasia chromatin anomalies fertility prognosis intracytoplasmic sperm injection intracytoplasmic injection of morphologically selected spermatozoa sperm neck defects sperm pathologies tail abnormalities teratozoospermia

来源：

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

Power-law Distribution of Normal fault Displacement and Length and estimation of extensional Strain due to Normal faults:A Case Study of the Sierra de San Miguelito, Mexico

引用

Acta Geologica Sinica(english edition) 2005年第1期79卷 36-42页

作者： XUShunshan A.f.NIeTO-SAMANIeGO S.A.ALANIZ-alvarez InstitutoMexicanodelPetrǒleo ProgramaYNFEjeCentralLázaroCárdenasNo.152Col.SanBartoloAtepehuacánC.P.07730 UniversidadNacionalAutǒnomadeMěxico CentrodegeocienciaApartadoPostal1-74276001QuerětaroQro.Měxoco／／InstituteofGeomechnicsChineseAcademyofGeologicalSciencesBeijing100081China.

The Sierra de San Miguelito is a relatively uplifted area and is constituted by a large amount of silicic volcanic rocks with ages from middle to late Cenozoic. The normal faults of the Sierra de San Miguelito are Domino-style and nearly parallel. The cumulative length and displacement of the faults obey power-law distribution. The fractal dimension of the fault traces is -1.49. Using the multi-line one-dimensional sampling, the calculated exponent of cumulative fault displacements is -0.66. A cumulative curve combining measurements of all four sections yielded a slope of -0.63. The displacement-length plot shows a non-linear relationship and large dispersion of data. The large dispersion in the plot is mainly due to the fault linkage during faulting. An estimation of extensional strain due to the normal faults is ca. 0.1830. The bed extension strain is always less than or equal to the horizontal extension strain. The deformation in the Sierra de San Miguelito occurred near the surface, producing pervasive faults and many faults are too small to appear in maps and sections at common scales. The stretching produced by small faults reach ca. 33% of the total horizontal elongation.

关键词： power-law distribution normal faults small faults finite strain Mexico

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Soil Pore Characterization Using free Software and a Portable Optical Microscope

引用

Pedosphere 2013年第4期23卷 503-510页

作者： L. f. PIReS f. S. borges S. PASSONI A. B. PeReIRA Department of Physics State University of Ponta Grossa (UEPG) Department of Soil Science State University of Ponta Grossa (UEPG)

Total porosity （TP）, determined by image analysis, pore type and pore size distribution were evaluated on impregnated soil blocks from an undisturbed Brazilian sandy loam soil using a digital portable optical microscope. The free software Image J （version 1.40g） was used for image analysis. Procedures for soil image collection and analysis were presented. The image analysis allowed the evaluation of pore sizes with diameters ranging from 20 to 〉 1 000 μm. The following types of pores were also obtained： rounded, elongated and intermediate. The results M[owed the characterization of the soil as moderately porous （TP = 21.6%）. Rounded, intermediate and elongated pores were responsible for 11.6%, 31.7% and 56.7% of TP. In relation to pore size 51.1% of TP was in the 100-500μm size class and a third of TP came from the pores larger than 500μm.

关键词： image analysis soil porosity soil structure pore size distribution

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

LefT-RIGHT BROWDeR LINeAR ReLATIONS AND RIeSZ PeRTURBATIONS

引用

Acta Mathematica Scientia 2017年第5期37卷 1437-1452页

作者： Teresa alvarez Department of Mathematics University of Oviedo33007OviedoAsturiasSpain

A closed linear relation T in a Banach space X is called left(resp. right) fredholm if it is upper(resp. lower) semi fredholm and its range(resp. null space) is topologically complemented in X. We say that T is left(resp. right) Browder if it is left(resp. right)fredholm and has a finite ascent(resp. descent). In this paper, we analyze the stability of the left(resp. right) fredholm and the left(resp. right) Browder linear relations under commuting Riesz operator perturbations. Recent results of Zivkovic et al. to the case of bounded operators are covered.

关键词： left and right fredholm linear relations left and right Browder linear relations Riesz perturbations

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

On Rigid 2-Step Nilpotent Lie Algebras

引用

Algebra Colloquium 2018年第2期25卷 349-360页

作者： Maria Alejandra alvarez Departamento de Matematicas Facultad de Ciencias Basicas Universidad de Antofagasta Casilla 170 Antofagasta Chile

In this note we consider 2-step nilpotent Lie algebras and give a criterion for the rigidity of this class in the variety N2n of 2-step nilpotent Lie algebras of dimension n. We apply this criterion to prove that ever... 详细信息

关键词： nilpotent Lie algebras variety of Lie algebras deformations cohomology,nilradicals

来源：

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

The role of endosomal cholesterol trafficking protein, StAR-related lipid transfer domain 3 （StarD3/MLN64）, in BRIN-BD11 insulinoma cells

引用

Protein & Cell 2016年第11期7卷 833-838页

作者： Joana borges Pinto Annette Graham Department of Life Sciences School of Health and Life Sciences Glasgow Caledonian University Glasgow G4 0BA UK WolfsonWohl Cancer Research Centre Institute of Cancer Sciences University of Glasgow Switchback Road Bearsden Glasgow G61 1QH UK

Dear editor, Insulin secretion by pancreatic β-cells is modulated by altering the cellular content and distribution of cholesterol, which is tightly regulated by a network of transcription factors, enzymes, receptors, transporters and cholesterol trafficking proteins. Inhibition of cellular biosynthesis by ＇statin＇ drugs, or depletion of plasma membrane cholesterol by methyl-β-cyclodextrin （MCD）, reduce glucose-stimulated insulin secretion （GSIS） and content in β-cells and islets;

关键词：

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Impact of rutin and buckwheat(fagopyrum esculentum)extract applications on the volatile and phenolic composition of wine

引用

food Bioscience 2022年第5期49卷 941-952页

作者： Juan Alberto Anaya Victoria Lizama Inmaculada alvarez María Jos´e García Institut Universitari d’enginyeria d’Aliments per al Desenvolupament Universitat Polit`ecnica de Val`encia46022ValenciaSpain

The aim of this research is to study the possibility of increasing the quality of red wins made with the Monastrell grape variety.A methodology was established to improve the concentration levels of polyphenol and aroma in these *** flavonoids,the copigmenting effect of rutin stands out,and was tested in both winery and field *** extract(fagopyrum esculentum),in which rutin is the main flavonoid,may be of interest for viticulture given its biological *** paper focuses on researching the effect of applying the prefermentative vegetable extract of buckwheat(fagopyrum esculentum)on the concentration of polyphenols and aroma compounds in ***,a study was carried out to compare the effect of pure copigment(rutin)when applied in vineyards and *** vinification was done,plus prefermentative cold *** application of buckwheat extract,and rutin extract to a lesser extent,to Monastrell grapes increased the concentration of malvidin and other anthocyanins,and total *** 12-month storage,no differences were observed in the percentage of copigmented,polymerised and free anthocyanin,the total polyphenol concentration,and the tannin quality parameters like DMACH(aldehyde p-dimethylaminoacimaldehyde)and the Gelatin *** concentrations of diethyl succinate,2 phenylethyl acetate,vanillin and ethyl octanoate increased,while other compounds decreased when the copigment was *** maceration technique followed during the vinification process had very little effect on polyphenolic *** prefermentative maceration slightly increasing the concentration of total polyphenols,but had no effect on the parameters related to colour,anthocyanin concentration,nature of anthocyanins,their binding state or tannin quality *** results showed that cold prefermentation maceration increased the concentration of some volatile compounds,including alcohols and esters,which should be con

关键词： Buckwheat Rutin Copigmentation Prefermentation maceration Wine Polyphenols Volatile compounds

来源：

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

Operation Strategies for Coordinating Battery energy Storage with Wind Power Generation and Their effects on System Reliability

引用

Journal of Modern Power Systems and Clean energy 2021年第1期9卷 190-198页

作者： Thais P.Teixeira Carmen L.T.borges the federal University of Rio de Janeiro Rio de JaneiroBrazil

The variability of wind power generation requires the allocation of a flexible energy reserve which is capable of compensating for possible imbalances between the load and generation. To reduce the variability of wind power generation and loss of load in generation deficit, we propose operation strategies for coordinating battery energy storage with wind power generation. The effects of the operation strategies on system reliability are evaluated by the developed computation model that represents the main aspects and operation limitations of the batteries. The performance evaluation of the power system is based on the composite reliability indices of loss of load probability(LOLP) and expected energy not supplied(eeNS), which is calculated through sequential Monte Carlo simulation. Tests are performed by the developed model with a tutorial system consisting of five busbars and the Ieee RTS system. The results show that the use of large-scale batteries is an alternative to physically guarantee the wind power plants and to act as an operation reserve to reduce the risk of loss of load.

关键词： energy storage wind power generation power system reliability Monte Carlo simulation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：