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Interfacial intermetallic compound growth and shear strength of low-silver SnAgCuBiNi/Cu lead-free solder joints

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International Journal of Minerals,Metallurgy and Materials 2013年第9期20卷 883-889页

作者： Guo-qiang Wei Lei Wang Xin-qiang Peng Ming-yang xue School of Mechanical and Automotive Engineering South China University of Technology

The growth rule of the interfacial intermetallic compound （IMC） and the degradation of shear strength of ***-0.5Cu-2.0Bi-0.05Ni （SACBN）/Cu solder joints were investigated in comparison with Sn-3.0Ag-0.5Cu （SAC305）/ Cu solder joints aging at 373, 403, and 438 K. The results show that （Cul-x,Nix）6Sn5 phase forms between the SACBN solder and Cu substrate during soldering. The interracial IMC thickens constantly with the aging time increasing, and the higher the aging temperature, the faster the IMC layer grows. Compared with the SAC305/Cu couple, the SACBN/Cu couple exhibits a lower layer growth coefficient. The activation energies of IMC growth for SACBN/Cu and SAC305/Cu couples are 111.70 and 82.35 kJ/mol, respectively. In general, the shear strength of aged solder joints declines continuously. However, SACBN/Cu solder joints exhibit a better shear strength than SAC305/Cu solder joints.

关键词： soldering alloys soldered joints aging intermetallics activation energy shear strength

Regularity of Solutions of the Cahn-Hilliard Equation with Non-constant Mobility

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Acta Mathematica Sinica,English Series 2006年第4期22卷 1139-1150页

作者： Chang Chun LIU Yuan Wei QI Jing xue YIN Department of Mathematics Jilin University Changchun 130012 P. R. China Department of Mathematics University of California Santa Barbara CA 93106 USA

In this paper, we study the regularity of solutions for two-dimensional Cahn-Hilliard equation with non-constant mobility. Basing on the L^p type estimates and Schauder type estimates, we prove the global existence of... 详细信息

关键词： Cahn-Hilliard equation regularity Schauder estimates

Coupling Thermomechanical and Microstructural FE Analysis in Plate Rolling Process

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Journal of Iron and Steel Research International 2008年第4期15卷 42-50页

作者： LI xue-tong WANG Min-ting DU Feng-shan College of Mechanical Engineering Yanshan University Qinhuangdao 066004 Hebei China

Using three-dimensional rigid-viscoplastic finite element method （FEM）, a coupling multivariable numerical simulation model for steel plate rolling has been established based on the physical metallurgy microstructural evolution rule and experiential equations. The effects of reduction, deformation temperature, and rolling speed on the deformation parameters and microstructure in plate rolling were investigated using the model. After a typical rolling process of steel plate 16Mn is simulated, the strain, temperature, and microstructure distributions are presented, as well as the ferrite grain transformation during the period of cooling. By comparing the calculated ferrite grain sizes with measured ones, the model is validated.

关键词： hot rolling plate FEM microstructure coupling

Precise large deviations for sums of random vectors in a multidimensional size-dependent renewal risk model

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Applied Mathematics(A Journal of Chinese Universities) 2018年第4期33卷 491-502页

作者： SHEN Xin-mei FU Ke-ang ZHONG xue-ting School of Mathematical Sciences Dalian University of Technology School of Statistics and Mathematics Zhejiang Gongshang University

Consider a multidimensional renewal risk model, in which the claim sizes {Xk, k ≥1} form a sequence of independent and identically distributed random vectors with nonnegative components that are allowed to be dependent on each other. The univariate marginal distributions of these vectors have consistently varying tails and finite means. Suppose that the claim sizes and inter-arrival times correspondingly form a sequence of independent and identically distributed random pairs, with each pair obeying a dependence structure. A precise large deviation for the multidimensional renewal risk model is obtained.

关键词： Precise large deviation Size-dependent Consistent variation Multidimensional risk model Renewal counting process

NUMERICAL STUDY ON PROPULSIVE PERFORMANCE OF FISH-LIKE SWIMMING FOILS

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Journal of Hydrodynamics 2006年第6期18卷 681-687页

作者： DENG Jian SHAO xue-ming REN An-lu Department of Mechanics State Key Laboratory of Fluid Power Transmission and Control Zhejiang UniversityHangzhou 310027 China

Two-dimensional numerical simulations are performed to study the propulsive performance of fish-like swimming foils using the immersed-boundary method. A single fish as well as two fishes in tandem arrangement are studied. First, the effect of the phase speed on the propulsive performance of a single fish is analyzed. The wake structures and pressure distribution near the wavy fish are also examined. The results show good correlation with those by previous researchers. Second, two tandem fishes with the same phase speed and amplitude are studied. The results show that the fish situated directly behind another one endure a higher thrust than that of a single one.

关键词： biomechanics fish-like swimming traveling wavy foil immersed-boundary method

Effects of ammonia concentration on morphology, composition and optical properties of ZnO_(1-x)S_(x) thin films of Cu(In, Ga)Se_(2) solar cells

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Optoelectronics Letters 2022年第4期18卷 215-221页

作者： WANG Lang xue Yuming WANG Zhiyong GUO Qing School of Integrated Circuit Science and Engineering Tianjin University of TechnologyTianjin 300384China

ZnO_(1-x)S_(x) films were prepared by chemical bath deposition(CBD)on glass *** effects of ammonia concentration on the structure characteristics of ZnO_(1-x)S_(x) films were *** results of scanning electron microscope(SEM)show that the film has good density when the concentration of ammonia is 0.4 *** more S2-ions are involved in the reaction and less precipitates are generated,the film is relatively *** distribution of the film element shows that the growth rate of the film first accelerates and then slows down as the concentration of ammonia increases.X-ray diffraction(XRD)study shows that the diffraction peak is obvious when the ammonia concentration is 0.4 M,and the crystallinity of the film is ***(UV)spectrophotometer test results show that the ratio of S content(x)and optical band gap(E_(g))satisfies E_(g)(x)=3.3257x^(2)-2.7187x+*** S content can increase the optical band gap of the film,and increasing ammonia concentration can improve the absorbance of the film,but both have good *** the ammonia concentration of 0.4 M,the absorbance of the film is good in the wavelength range of 300—900 nm,the transmission rate reaches 80%,and the band gap is 3.75 e V,which is suitable for the buffer layer of solar cells.

关键词： ammonia film concentration

神经系统自身免疫性疾病发病机制与治疗研究进展

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中国现代神经疾病杂志 2010年第1期10卷 49-63页

作者：龙友明胡学强中山大学附属第三医院神经病学科广州510630

神经系统自身免疫性疾病是以自体免疫细胞、免疫分子等攻击神经系统为主要病理机制的自身免疫性疾病，可发生在中枢神经系统、周围神经系统及神经．肌肉接头处，导致神经元或轴索损伤、髓鞘脱失、神经-肌肉接头破坏等病理改变。在中枢... 详细信息

神经系统自身免疫性疾病是以自体免疫细胞、免疫分子等攻击神经系统为主要病理机制的自身免疫性疾病，可发生在中枢神经系统、周围神经系统及神经．肌肉接头处，导致神经元或轴索损伤、髓鞘脱失、神经-肌肉接头破坏等病理改变。在中枢神经系统以多发性硬化（MS）、视神经脊髓炎（NMO）为代表，在周围神经系统以急性炎性脱髓鞘性多发性神经病（AIDP）如格林-巴利综合征（GBS）为代表，

关键词：神经系统自身免疫性疾病实验性药物疗法综述

Recursive Bayesian Algorithm for Identification of Systems with Non-uniformly Sampled Input Data

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International Journal of Automation and computing 2018年第3期15卷 335-344页

作者： Shao-xue Jing Tian-Hong Pan Zheng-Ming Li School of Electrical Information and Engineering Jiangsu University Department of Electrical Engineering Huaian College of Information and Technology

To identify systems with non-uniformly sampled input data, a recursive Bayesian identification algorithm with covariance resetting is proposed. Using estimated noise transfer function as a dynamic filter, the system with colored noise is transformed into the system with white noise. In order to improve estimates, the estimated noise variance is employed as a weighting factor in the algorithm. Meanwhile, a modified covariance resetting method is also integrated in the proposed algorithm to increase the convergence rate. A numerical example and an industrial example validate the proposed algorithm.

关键词： Parameter estimation discrete time systems Gaussian noise Bayesian algorithm covariance resetting.

Synthesis and Crystal Structure of N,N′-Bis(p-nitrophenyl)-2,2′-(p-phenylene-dioxy)diacetamide DMF Monohydrate

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Chinese Journal of Structural Chemistry 2005年第5期24卷 591-595,493页

作者： LI xue-Mei WEN Yong-Hong LIANG Juan ZHANG Shu-Sheng College of Chemistry and Molecular Engineering Qingdao University of Science and TechnologyQingdao 266042China

A new complex of N,N?-bis(p-nitrophenyl)-2,2?-(p-phenylene-dioxy) diacetamide DMF monohydrate, C25H25N5O9·H2O (Mr = 557.52), has been synthesized and its structure was determined by X-ray crystallography method. The crystal belongs to monoclinic system, space group P21/c with a = 7.2812, b = 25.5894, c = 14.3434 ?, β = 91.110(1)o, V = 2672.0(2) ?3, Dc = 1.386 g/cm3, F(000) = 1168, μ = 0.109 mm-1 and Z = 4. The final R = 0.0493 and wR = 0.1173 for 3389 observed reflections with I > 2σ(I). The asymmetric unit of the title complex consists of monomeric N,N?-bis(p-nitrophenyl)-2,2?-(p-phenyleneioxy)diacetamide 1, one DMF and one water molecule, which are incorporated during recrystallization. The molecules are linked into a three-dimensional network by π…π interactions as well as intermolecular interactions among DMF, water molecule and 1.

关键词： N,N′-bis(p-nitrophenyl)-2,2′-(p-phenylenedioxy)diacetamide synthesis crystal structure