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Prediction and Control of both Wrinkle Limit and Fracture Limiton Cylindrical Cup Deep-drawing(Ⅱ)

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International Journal of Minerals,Metallurgy and Materials 1999年第3期13卷 201-204页

作者： Junxiang Lei Yonglin Kang(department of Mechanical Engineering, Yantai university, Yantai 2.4005, {2.)(Material science and Engineering School, university of science and technology beijing, beijing 100083, {2.) department of Mechanical Engineering Yantai University Yantai 264005 China Material science and Engineering School University of Science and Technology Beijing Beijing 100083 China

The prediction and control criterion of both the wrinkle limit and fracture limit on the cylindrical cup deep-drawing are given, and the prediction and control diagram of both the wrinkle limit and fracture limit are also given. The results show that it is suitable for no-flange cylindrical cup deep-drawing, narrow-flange cylindrical cup deep-drawing, wide-flange cylindrical cup deep-drawing/expanding compound forming and rigid punch expanding forming.

关键词： cylindrical cup wrinkle limit fracture limit deep-drawing expanding forming compound forming

THE PHYSICAL ENTROPY OF SINGLE CONSERVATION LAWS

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Journal of Computational mathematics 1998年第5期16卷 437-444页

作者： (department of mathematics, Peking {2., beijing 100871, china) 北京大学数学系北京

By means of the comparisons with the formulas in statistical mechanics and thermodynamics, in this paper it is demonstrated that for the single conservation law partial derivative(t)u + partial derivative(x)f(u) = 0, if the flux function f(u) is convex (or concave), then, the physical entropy is S = -f(u); Furthermore, if we assume this result can be generalized to any f(u) with two order continuous derivative, from the thermodynamical principle that the local entropy production must be non-negative, one entropy inequality is derived, by which the O.A. Olejnik's famous E- condition can be explained successfully in physics.

关键词： conservation laws entropy entropy production

Discrepancy of the magnetic behaviors and crystalline structure on the Co/FeMn and FeMn/Co interfaces with ultrathin Pt spacer

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Rare Metals 2010年第5期29卷 473-479页

作者： LIU Yang,FU Yanqiang,JIN Chuan,and FENG Chun department of Materials Physics and Chemistry,university of {2. and technology beijing,beijing 100083,china department of Materials Physics and Chemistry University of Science and Technology Beijing Beijing China

The exchange coupling at the ferromagnetic/antiferromagnetic （FM/AFM） interface is influenced by both the magnetic structure and the crystalline micro-structure. Co/FeMn/Co thin films with 0.4 nm Pt spacer layer inserted into the Co/FeMn and FeMn/Co interface respectively were deposited by means of magnetron sputtering. The two interfaces upon and beneath the FeMn layer show distinct behaviors before and after the Pt spacer inserted. There is a remarkable shrink of the interracial uncompensated spins within the FeMn bottom interracial monolayers, whereas a relaxation of the pinning strength of the FeMn interfacial spins along the out-of-plane direction occurs at the top in- terface. XRD analysis indicates the Pt layer upon the FeMn layer forms an fcc （002. texture, implying the magnetic discrepancy between the top and bottom FeMn interfaces has crystalline structural origins.

关键词： interfaces exchange coupling exchange bias spacer stress anisotropy lattice match

A BATCH ARRIVAL RETRIAL QUEUE WITH STARTING FAILURES,FEEDBACK AND ADMISSION CONTROL

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Journal of Systems science and Systems Engineering 2010年第3期19卷 306-320页

作者： Jinting WANG Peng-Feng ZHOU department of mathematics,School of {2.,beijing Jiaotong university,beijing,china department of mathematics School of Science Beijing Jiaotong University Beijing China

This paper is concerned with the analysis of a feedback M^[X]/G/1 retrial queue with starting failures and general retrial times. In a batch, each individual customer is subject to a control admission policy upon arrival. If the server is idle, one of the customers admitted to the system may start its service and the rest joins the retrial group, whereas all the admitted customers go to the retrial group when the server is unavailable upon arrival. An arriving customer （primary or retrial） must turn-on the server, which takes negligible time. If the server is started successfully （with a certain probability）, the customer gets service immediately. Otherwise, the repair for the server commences immediately and the customer must leave for the orbit and make a retrial at a later time. It is assumed that the customers who find the server unavailable are queued in the orbit in accordance with an FCFS discipline and only the customer at the head of the queue is allowed for access to the server. The Markov chain underlying the considered queueing system is studied and the necessary and sufficient condition for the system to be stable is presented. Explicit formulae for the stationary distribution and some performance measures of the system in steady-state are obtained. Finally, some numerical examples are presented to illustrate the influence of the parameters on several performance characteristics.

关键词： Batch arrival feedback repair retrial queue starting failure

SIZE DISTRIBUTION AND BEHAVIOUR OF VC PARTICLES IN FERRITIC NODULAR CAST IRON

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Acta Metallurgica Sinica(English Letters) 1993年第8期6卷 92-97页

作者： WANG Yu SONG Weixi HAN Qiyong university of science and {2. beijing,beijing,china The Institute of Precise and Special New Materials, university of science and {2. beijing,beijing 100083,china beijing Univ of science and Technology Beijing China

Size distribution and precipitation of VC particles in ferritic nodular cast iron have been examined by techniques of ultrasonic screening,small angle X-ray scattering and chemical *** VC particles are sized over a wide *** superfine ones, dispersed in the ferritic matrix,are the majority.A saturated dispersion with ultrafine VC particles may be approached as the V content increasing in the ***5 seems to play an important role in the precipitation strengthening for ferritic nodular cast iron.

关键词： nodular cast iron ferrite size distribution VC particle

Calculating Model of Mass Action Concentrations for Fe-Cr-P Melts and Optimization of Thermodynamic Parameters

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International Journal of Minerals,Metallurgy and Materials 1999年第1期13卷 11-14页

作者： Jian Zhang (Metallurgy School, university of science and {2. Beliing, beijing 100083, china) Metallurgy School University of Science and Technology Beijing Beijing 100083 China

According to the results of research on the thermodynamic propelles of Fe-Cr, Fe-P and Cr-P melts, the measured achvihes of Fe-Cr-P melts from reference sources as well as the coexistence theory of metallic melts structure involving compound formation, a calculating model of the mass action concentrations for Fe-Cr-P melts has been formulated and some of its thermodynamic parameters have been optimized. The calculated mass action concentrations agree with the measured achvities, which shows that this model can reflect the structural reality of Fe-Cr-P melts.

关键词： activity dephosphorization of stainless steel, coexistence theory mass action concentration

ELECTROPLATING　OF　AMORPHOUS　Al－Mn　ALLOYS　（I） KINETIC　FEATURES　OF　ELECTRODEPOSITION　OF　PURE　Al

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中国有色金属学会会刊：英文版 1996年第4期6卷 35-37页

作者： Zhao Guangwen Zhu Teng Liu Lianyu(department of Physicochemistry,university of {2. and technology beijing,beijing 100083) department of Physicochemistry University of Science and Technology Beijing Beijing 100083 China

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关键词： electroplating AlCl3-NaCl-KCl melt electrodeposition pure Al

Theoretical study on the size consistency of the second and third order energies of the multireference perturbation theory

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science china Chemistry 2007年第4期50卷 483-487页

作者： CHEN FeiWu department of Chemistry, university of {2. and technology beijing, beijing 100083, china (email: chenfeiwu@***) department of Chemistry University of Science and Technology Beijing Beijing China

The size consistency of the second and third order energies of the multireference perturbation theory(Chen F, Davidson E, Iwata S. Int J Quant Chem, 2.02. 86: 2.6) is investigated theoretically with a su-per-molecular model composed of N-hydrogen molecules separated by a large distance. It is found that the two perturbation series corresponding to two Hamiltonian partitions are not size consistent at the second and third order. However, two size consistent forms are suggested for two Hamiltonian parti-tions at the second order, if some approximations to the denominators of the original second order energies are assumed.

关键词： size consistency multireference perturbation theory

EFFECT OF COMPOSITION ON HYDROGEN EMBRITTLEMENT IN Ni-Fe FCC ALLOYS

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Acta Metallurgica Sinica(English Letters) 1992年第6期5卷 443-448页

作者： HU Wei WANG Yanbin CHU WuYang XIAO Jimei university of science and {2. beijing,china Associate Professor,department of Materials Physics,university of science and {2. beijing,beijing 100083,china beijing Univ of science and Technology Beijing China

The ductility loss and threshold stress intensity,K_(IH)during hydrogen charging were measured for pure Ni and four Ni-Fe fcc *** results show that ductility loss in 40Ni60Fe alloy and K_(IH)a 50Ni50Fe alloy have a minimum *** variations of the amounts of hydride, hydrogen evolution and dislocation structure with composition have been *** va- riation of hydrogen embrittlement susceptibility with composition measured by ductility loss and by K_(IH)or K_(IH)/K_C can be explained by means of the synthetical effects of amount of hydride,solutionized hydrogen and the extent of dislocation planarity on hydrogen embrittlement susceptibility.

关键词： Ni-Fe alloys hydrogen embrittlement