检索结果-南通市图书馆

The Transformation of the Heterogeneous Materials under the Fatigue Deformation

在线全文

学校读者我要写书评

暂无评论

Materials Sciences and Applications 2012年第6期3卷 398-407页

作者： S. kh. Shamirzaev j. k. Ziyovaddinov Sh. B. karimov Physical Technical Institute of Uzbek Academy of Sciences Tashkent Republic of Uzbekistan

The objects of our paper are aluminum alloy samples (AASs) contained the different amount of Cu, Mn, Mg, Si and Li. We are modeling the features of microstructure of potential relief of an AAS and studying its transformation under both imposed fatigue deformation and wetted by liquid metals (Ga;or Hg;Li;In). We illustrate the main ideas by using only the “time series” allied with effective internal friction Q-1eff of an AAS. AASs like B-95 or 7075 are heterogeneous materials for which the more energy can be absorbed by selected micro-regions of a tested sample. So micro-crack in the space of AAS and alarm state of AAS arises. Each micro-region will to contribute the Q-1k (the internal friction Q-1k belong to k-th micro-region) to the effective internal friction— Q-1eff accordance with fit statistic . We find a number of micro-regions—L and series gk & Qk from the experimental data like as the internal friction (Q-1)eff versus both the number of cycles—N and the deformation—е. Series gk & Qk (k=1,2,3,...,L) present the microstructures of AASs. In this paper also is presented the original technology to forecast fatigue damage of an AAS. Here the fatigue sensitive element (FSE) used. We made multiphase heterogeneous mixtures (MHMs) which contents a variable volume of initial components. It is selected MHMs are using for produce FSEs. The present paper is aimed to establish the correlation of the FSEs microstructures changes and corresponding changes of the aluminum alloy microstructures at imposing the same spectra deformation on both of them. A change of FSEs microstructure investigated by using their effective electrical resistance Reff data.

关键词： Amplitude-Dependent Internal Friction Fatigue Cracking Process Alarm State Fatigue Sensitive Element

A Mathematical Analysis of Scale Similarity

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

Communications in Computational Physics 2017年第1期21卷 149-161页

作者： Z.j.Wang Yanan Li Department of Aerospace Engineering University of Kansas2120 Learned HallLawrenceKS 66045USA

Scale similarity is found in many natural phenomena in the universe,from fluid dynamics to *** large eddy simulations of turbulent flows,some sub-grid scale(SGS)models are based on scale *** earliest scale similarity SGS model was developed by Bardina et al.,which produced SGS stresses with good correlation to the true *** the present study,we perform a mathematical analysis of scale *** analysis has revealed that the ratio of the resolved stress to the SGS stress is g2,where g is the ratio of the second filter width to the first filter width,under the assumption of small filter *** implications of this analysis are discussed in the context of large eddy simulation.

关键词： Scale similarity large eddy simulation sub-grid scale models

HSV gene transfer in the treatment of chronic pain

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

生理学报 2008年第5期60卷 610-616页

作者： David j. Fink Marina Mata University of Michigan and VA Ann Arbor Healthcare System Ann Arbor Michigan 48109 USA

It has proven difficult to use systemic administration of small molecules to selectively modulate *** the past decade,we and others have developed non-replicating herpes simplex virus(HSV)-based vectors to treat chronic *** inoculation of an HSV vector effectively transduces sensory neurons in the dorsal root ganglion;release of transgene-coded inhibitory neurotransmitters or anti-inflammatory peptides reduces pain-related behaviors in rodent models of chronic inflammatory and neuropathic pain.A phase 1 trial of this therapy in patients is set to begin soon.

关键词： HSV 基因慢性疼痛临床分析病症

在线全文

学校读者我要写书评

暂无评论

应用EMME／2宏语言执行道路定价模型

上海理工大学学报 1999年第3期21卷 333-341页

作者： Wheway,j Checuk,k 香港联合有限公司香港555NathanRoad!香港中国

香港的交通拥挤非常严重，而且好像并不能通过增加道路容量来解决，考虑到大多数拥挤地区空间的限制和增加道路容量所导致的潜在需求，交通规划人员和经济专家们为解决交通拥挤问题，已经把他们的注意力从交通供方面转移交通需求上。道... 详细信息

香港的交通拥挤非常严重，而且好像并不能通过增加道路容量来解决，考虑到大多数拥挤地区空间的限制和增加道路容量所导致的潜在需求，交通规划人员和经济专家们为解决交通拥挤问题，已经把他们的注意力从交通供方面转移交通需求上。道路定价方法可构成交通需求管理战略的一部分，为交通拥挤问题提供了一个有效、公平、灵活的解决方案。香港特共政府已指定了一个咨询机构，来调查电子道路定价系统的需求，以及执行后的社会反应。

关键词：交通模型 EMME/2 交通需求道路定价

Stance Mazda CX-4又见不务正业

在线全文

学校读者我要写书评

暂无评论

汽车与运动 2017年第11期 102-107页

作者： j.k.Photograph

马自达CX-4上市于2016年6月,时至今日,已有一年多的时间了,在路上的能见度虽不算高,但也是有一些的,和马自达的其他车型一样,依旧处于叫好不叫座的现状,不知道是价格的因素还是定位的模糊,拿来进行改装的更是少之又少,不过今天我们带来... 详细信息

马自达CX-4上市于2016年6月,时至今日,已有一年多的时间了,在路上的能见度虽不算高,但也是有一些的,和马自达的其他车型一样,依旧处于叫好不叫座的现状,不知道是价格的因素还是定位的模糊,拿来进行改装的更是少之又少,不过今天我们带来的这台CX-4,不仅改装了。

关键词： Mazda 马自达能见度改装

Semantic-Discovery of Construction Project Files

在线全文

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2008年第S1期13卷 305-310页

作者：潘佳怡 Chimay j. Anumba Department of Construction Management Tsinghua University Department of Architectural Engineering The Pennsylvania State University

The dynamics of a construction project generates a huge amount of information for processing. Most project information is recorded in digital files and managed in a decentralized way. Current document management tools do not consider the semantic relationships between files and then cannot discover files based on their content or ensure information consistency across various information repositories. This paper presents a semantic-discovery method for accessing project information across repositories. By adopting semantic web technologies, including extensible markup language (XML), ontology, and logic rules, the semantic-discovery tool can access project files by their properties and relations. The method has been applied to searching for files using documents from a real project. The results show that the semantic content of a file can be used to ensure that only related files are retrieved.

关键词： construction projects management information system semantic web content-based informa-tion management ontology extensible markup language (XML) resource definition framework (RDF)

Ordered Rate Constitutive Theories for Non-Classical Thermoviscoelastic Fluids with Internal Rotation Rates

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics 2018年第8期9卷 907-939页

作者： k. S. Surana S. W. Long j. N. Reddy Department of Mechanical Engineering University of Kansas Lawrence KS USA Department of Mechanical Engineering Texas A & M University College Station TX USA

The paper presents constitutive theories for non-classical thermoviscoelastic fluids with dissipation and memory using a thermodynamic framework based on entirety of velocity gradient tensor. Thus, the conservation and the balance laws used in this work incorporate symmetric as well as antisymmetric part of the velocity gradient tensor. The constitutive theories derived here hold in coand contra-variant bases as well as in jaumann rates and are derived using convected time derivatives of Green’s and Almansi strain tensors as well as the Cauchy stress tensor and its convected time derivatives in appropriate bases. The constitutive theories are presented in the absence as well as in the presence of the balance of moment of moments as balance law. It is shown that the dissipation mechanism and the fading memory in such fluids are due to stress rates as well as moment rates and their conjugates. The material coefficients are derived for the general forms of the constitutive theories based on integrity. Simplified linear (or quasi-linear) forms of the constitutive theories are also presented. Maxwell, Oldroyd-B and Giesekus constitutive models for non-classical thermoviscoelastic fluids are derived and are compared with those derived based on classical continuum mechanics. Both, compressible and incompressible thermoviscoelastic fluids are considered.

关键词： Rate Constitutive Theories Non-Classical Thermofluids With Memory Convected Time Derivatives Internal Rotation Gradient Tensor Generators and Invariants Cauchy Moment Tensor

Assessing dominant factors affecting soil erosion using a portable rainfall simulator

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

International journal of Sediment Research 2008年第4期23卷 376-386页

作者： j.VAHABI D.NIkkAMI Soil Conservation and Watershed Management Research Institute

Investigating the causes of soil erosion is difficult in natural conditions owing to the presence of other factors. Without simplifying the experimental conditions, studying soil behavior with its numerous parameters while considering factors such as vegetation cover, topography, and rainfall is difficult and in most conditions impossible. The application of simulation approaches is therefore necessary to simplify the prototype. In this research, the effects of physical soil factors such as texture and antecedent soil moisture, along with land slope and vegetation cover were evaluated in the Taleghan watershed, Iran, using a rainfall simulator and soil erosion plots. For this purpose, a 89 × 120 cm rainfall simulator producing 24.5 and 32 mm/h rainfall intensities of 30 min duration, as a common condition of the study area, was used at 144 locations over soil erosion plots with dimensions of 95 × 125 cm. Plots had slope classes of 12–20 and 20–30 %, different soil textures, different antecedent soil moistures, and medium to poor vegetation cover conditions. It was found that for 24.5 and 32 mm/h rainfall intensities, the sediment yield had high correlations of –0.771 and –0.796 with vegetation cover and slight correlations of 0.045 and 0.029 with land slope respectively. Regression equations for predicting the sediment yield were also developed for different conditions.

关键词： Rainfall simulator Soil erosion Soil physical parameters Vegetation cover Taleghan watershed Iran

EFFECT OF BRAZING TIME ON TiC CERMET/IRON jOINT BRAZED WITH Ag-Cu-Zn FILLER METAL

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2004年第1期17卷 107-110页

作者： L.X.Zhang j.C.Feng Z.R.Li H.j.Liu National key Laboratory of Advanced Welding Production Technology Harbin Institute of Technology Harbin 150001 ChinaNational Key Laboratory of Advanced Welding Production Technology Harbin Institute of Technology Harbin 150001 ChinaNational Key Laboratory of Advanced Welding Production Technology Harbin Institute of Technology Harbin 150001 ChinaNational Key Laboratory of Advanced Welding Production Technology Harbin Institute of Technology Harbin 150001 China

The brazing of TiC cermet to iron was carried out at 1223k for 5-20min using Ag-Cu-Zn filler metal. The formation phase and interface structure of the joints were investigated by electron probe microanalysis (EPMA), scanning electron microscopy (SEM) and X-ray diffraction (XRD), and the joint strength was tested by shearing method. The results showed: there occurred three new formation phases, Cu(s.s), FeNi and Ag(s.s) in TiC cermet/iron joint. The interface structure was expressed as TiC cermet/Cu(s.s)+FeNi/Ag(s.s)+a little Cu(s.s)+a little FeNi/Cu(s.s)+FeNi/iron, With brazing time increasing, there appeared highest shear strength of the joints, the value of which was up to 252.2MPa when brazing time was 10min.

关键词： brazing TiC cermet interface shear strength