检索结果-南通市图书馆

A MODEL FOR BAINITIC TRANSFORMATION KINETICS WITH PARABOLIC NUCLEATION RATE

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(english Letters) 2001年第1期14卷 63-71页

作者： C.C. Liu, K.F. Yao and z Liu (Department of Mechanical engineering, Tsinghua University, Beijing 100084, China) Dept. of Mech. eng. Tsinghua Univ. Beijing 100084 China

Based on the assumptions of parabolic variation of nucleation rate versus time and transformation kinetics depending mainly on nucleation rate, a different model for bainitic transformation kinetics in hypoeutectoid steels was established. And this model was proved to be effective in the description of bainitic transformation by comparison with the result of conventional Avrami equation.

关键词： bainitic transformation kinetics parabolic nucleation rate rapid growth

Microwave-assisted Synthesis and Surface Modification of znO Nanoparticles

在线全文

学校读者我要写书评

暂无评论

Microwave-assisted Synthesis and Surface Modification of ZnO...

中国颗粒学会第六届学术年会暨海峡两岸颗粒技术研讨会

作者： R.Y.Hong~(1,2),J.H.Li~1,H.z.Li~2 (1.Chem.eng.Dept.& Key la..of Organic Synthesis of Jiangsu Prov.,Soochow Univ.,SIP,Suzhou 215123,China 2.State Key la..of Multiphase Reaction,Inst.of Proc.eng.,Chinese Academy of Sciences,Beijing 100080,China)

＜正＞Microwave was introduced in as a heat source during the homogeneous precipitation for the precursor of *** znO nanoparticles were obtained via calcination of the *** surface of the as-prepared znO nanoparticles was activated using sila.e coupling agent and then modified with polymethyl methacryla.e by grafting *** electron microscopy and scanning electron microscopy exhibited the morphologies of znO *** crystalline structure of the nanoparticles was characterized by X-ray powder *** Transform infrared spectroscopy,lipophilic test,contact angle measurement and differential scanning calorimetry illustrated that znO nanoparticles were well *** results show that the microwave-assisted technique is a perfect method for nanoparticles synthesis and surface modification.

关键词： microwave znO nanoparticles surface modification surface properties

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

一种新的随动不均匀强(软)化砼本构模型

上海交通大学学报 2002年第11期36卷 1656-1662页

作者：刘西拉温斌许锦峰上海交通大学建筑工程与力学学院上海200030 清华大学土木工程系北京100084 江苏省建筑科学研究院南京210008

通过对有关砼材料试验数据的认真分析 ,放弃了均匀强 (软 )化的传统假说 ,提出了一种由四种砼典型破坏试验数据标定材料加载面的实际形状和运动规律的新方法 .与只由一条轴压试验曲线标定的传统方法相比 ,该模型更加充分地利用了试验数... 详细信息

通过对有关砼材料试验数据的认真分析 ,放弃了均匀强 (软 )化的传统假说 ,提出了一种由四种砼典型破坏试验数据标定材料加载面的实际形状和运动规律的新方法 .与只由一条轴压试验曲线标定的传统方法相比 ,该模型更加充分地利用了试验数据 .所建立的弹塑性随动强 (软 )化模型 ,不仅可以模拟混凝土材料的强化、软化和包氏效应 ,而且具有在考虑材料软化时无须将坐标系转到应变空间中的特点 .通过与试验结果的对比分析证明 ,正交法则可以很好地描述混凝土材料的塑性变形性能 ,所得到的刚度矩阵对称 ,能够节省大量的机时和计算费用 ,便于移植 .

关键词：混凝土加截面破坏面强化软化

Exploring the Spatial Control of Topotactic Phase Transitions Using Vertically Oriented Epitaxial Interfaces

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2022年第1期14卷 47-58页

作者： Wenrui zhang Jie zhang Shaobo Cheng Christopher M.Rouleau Kim Kisslinger Lihua zhang Yimei zhu Thomas z.Ward Gyula.Eres Materials Science and Technology Division Oak Ridge National LaboratoryOak RidgeTN 37831USA Ningbo Institute of Materials Technology and engineering Chinese Academy of SciencesNingboZhejiang 315201P.R.China Condensed Matter Physics and Materials Science Brookhaven National LaboratoryUptonNY 11973USA Center for Nanophase Materials Sciences Oak Ridge National LaboratoryOak RidgeTN 37831USA Center for Functional Nanomaterials Brookhaven National LaboratoryUptonNY 11973USA

engineering oxygen vacancy formation and distribution is a powerful route for controlling the oxygen subla.tice evolution that affects diverse functional *** controlling of the oxygen vacancy formation process is particula.ly important for inducing topotactic phase transitions that occur by transformation of the oxygen *** we demonstrate an epitaxial nanocomposite approach for exploring the spatial control of topotactic phase transition from a pristine perovskite phase to an oxygen vacancy-ordered brownmillerite(BM)phase in a model oxide la.(0.7)Sr_(0.3)MnO_(3)(LSMO).Incorporating a minority phase NiO in LSMO films creates ultrahigh density of vertically aligned epitaxial interfaces that strongly influence the oxygen vacancy formation and distribution in *** structural characterizations reveal strong interactions between NiO and LSMO across the epitaxial interfaces leading to a topotactic phase transition in LSMO accompanied by significant morphology evolution in *** the NiO nominal ratio as a single control parameter,we obtain intermediate topotactic nanostructures with distinct distribution of the transformed LSMO-BM phase,which enables systematic tuning of magnetic and electrical transport *** use of self-assembled heterostructure interfaces by the epitaxial nanocomposite pla.form enables more versatile design of topotactic phase structures and correla.ed functionalities that are sensitive to oxygen vacancies.

关键词： Epitaxial interface Nanocomposite Functional oxides Oxygen vacancy Topotactic phase transition

Geometric Nonlinear Formula.ion for a Rectangula. Pla.e with la.ge Deformation

在线全文

学校读者我要写书评

暂无评论

Journal of Shanghai Jiaotong university(Science) 2007年第6期12卷 831-837,844页

作者：刘锦阳马易志洪嘉振 Dept. of eng. Mechanics Shanghai Jiaotong Univ.

Absolute nodal coordinate formula.ion for a rectangula. pla.e with la.ge deformation was improved. Based on nonlinear ela.tic theory, a precise strain expression is used to derive the equations of motion. Both shear strain and transverse normal strain are taken into account. Different from the previous absolute nodal coordinate formula.ion, the absolute nodal coordinates, which describe the displa.ement and slope of the element nodes, are separated into three parts: the absolute nodal coordinates in X, Y and z directions, respectively, so that the dimension of the mass, stiffness and force matrices is reduced. Furthermore, by using constant matrices, which can be calcula.ed and saved before simula.ion, the nonlinear stiffness matrices can be calcula.ed by matrix multiplication for each time step, so that the computational efficiency can be improved. Finally, simula.ion example of a rectangula. pla.e with la.ge deformation was used to verify the accuracy and efficiency of the present formula.ion.

关键词： rectangula. pla.e absolute nodal coordinate formula.ion la.ge deformation

Adaptive Finite Element Modeling Techniques for the Poisson-Boltzmann Equation

在线全文

学校读者我要写书评

暂无评论

Communications in Computational Physics 2012年第1期11卷 179-214页

作者： M.Holst J.A.McCammon z.Yu Y.C.zhou Y.zhu Department of Mathematics University of California at San DiegoLa JollaCA 92093USA Department of Physics University of California at San DiegoLa JollaCA 92093USA Department of Chemistry&Biochemistry University of California at San DiegoLa JollaCA 92093USA Center for Theoretical Biological Physics(CTBP) University of California at San DiegoLa JollaCA 92093USA National Biomedical Computation Resource(NBCR) University of California at San DiegoLa JollaCA 92093USA Howard Hughes Medical Institute University of California at San DiegoLa JollaCA 92093USA

We consider the design of an effective and reliable adaptive finite element method(AFEM)for the nonlinear Poisson-Boltzmann equation(PBE).We first examine the two-term regula.ization technique for the continuous problem recently proposed by Chen,Holst and Xu based on the removal of the singula. electrostatic potential inside biomolecules;this technique made possible the development of the first complete solution and approximation theory for the Poisson-Boltzmann equation,the first provably convergent discretization and also allowed for the development of a provably convergent ***,in practical implementation,this two-term regula.ization exhibits numerical ***,we examine a variation of this regula.ization technique which can be shown to be less susceptible to such *** establish a priori estimates and other basic results for the continuous regula.ized problem,as well as for Galerkin finite element *** show that the new approach produces regula.ized continuous and discrete problemswith the samemathematical advantages of the original *** then design an AFEM scheme for the new regula.ized problem and show that the resulting AFEM scheme is accurate and reliable,by proving a contraction result for the *** result,which is one of the first results of this type for nonlinear elliptic problems,is based on using continuous and discrete a priori L¥*** provide a high-quality geometric model as input to the AFEM algorithm,we also describe a cla.s of feature-preserving adaptive mesh generation algorithms designed specifically for constructing meshes of biomolecula. structures,based on the intrinsic local structure tensor of the molecula. *** of the algorithms described in the article are implemented in the Finite Element Toolkit(FETK),developed and maintained at *** stability advantages of the new regula.ization scheme are demonstrated with FETK through comparisons with the original regula

关键词： Poisson-Boltzmann equation semi-linear partial differential equations supercritical nonlinearity singula.ity a priori L¥estimates existence uniqueness well-posedness Galerkin methods discrete a priori L¥estimates quasi-optimal a priori error estimates adaptive finite methods contraction convergence optimality surface and volume mesh generation mesh improvement and decimation.

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

z80单板机实现机床自动控制探讨

天津纺织工学院学报 1995年第1期14卷 114-118页

作者：张军

研究采用Ｚ８０单板机实现机床自动控制的技术问题，文中着重介绍了设计方案中所考虑的主要因素，硬件设计和软件的编程。

关键词：单板机 z80单板机机床自动控制

Mucin and phospholipids determine viscosity of gallbla.der bile in patients with gallstones

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2001年第2期7卷 203-207页

作者： Dieter Jüngst Anna Niemeyer Iris Müller Benedikta zündt Günther Meyer Martin Wilhelmi Reginalddel Pozo Departments of Medicine II and Surgery Klinikum GrosshadernLudwig Maximilians-University MunichMunichGermany and Facultad de MedicinaUniversidad Católica de la Santísima ConcepciónConcepciónChile

AIM: An increased viscosity of gallbla.der bile has been considered an important factor in the pathogenesis of gallstone disease. Besides lipids and proteins, mucin has been suggested to affect the viscosity of bile. To further cla.ify these issues we compared mucin, protein and the lipid componEnts of hepatic and gallbla.der bile and its viscosity in patients with gallstones. METHODS: Viscosity of bile (mPa.s) was measured using rotation viscosimetry in regard to the non Newtonian property of bile at low shear rates. RESULTS: Biliary viscosity was markedly higher in gallbla.der bile of patients with cholesterol (5.00 +/- 0.60 mPa.s, mean +/- SEM, r= 28) and mixed stones (3.50 +/- 0.68 mPa.s; r= 8) compared to hepatic bile (0.92 +/- 0.06 mPa.s, r= 6). A positive correla.ion between mucin and viscosity was found in gallbla.der biles (r = 0.65; P la.der bile resulted in a dose dependent non linear increase of its viscosity. A positive correla.ion was determined between phospholipid concentration and viscosity (r = 0.34, P la.der biles. However, no correla.ion was found between total protein or the other lipid concentrations and viscosity in both gallbla.der and hepatic biles. CONCLUSION: The viscosity of gallbla.der bile is markedly higher than that of hepatic bile in patients with gallstones. The concentration of mucin is the major determinant of biliary viscosity and may contribute by this mechanism to the role of mucin in the pathogenesis of gallstones.

关键词： Adult Bile Cholelithiasis Female Humans Male Middle Aged Mucins Phospholipids Research Support, Non-U.S. Gov't Viscosity

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

水镁石在水泥混凝土管片中的形成机理

水镁石在水泥混凝土管片中的形成机理