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Electro-Pulse on Improving Steel Ingot Solidification Structure

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International Journal of Minerals,Metallurgy and Materials 1999年第2期13卷 94-96页

作者： Yong Tang Jianzhong Wang Daqing Cang(Metallurgy school, university of {2. and technology beijing, beijing 100083, china. Metallurgy school University of Science and Technology Beijing Beijing 100083 China

Pulse Electric Discharging (PED) is a novel technique that can modify solidifying structure and reduce grain size. ItS effectsapplied to the high carbon liquid steel were presented here. The macrostructure and microstructure of the high carbon alloy steel werealso observed. Results show that (1 ) the length of columnar crystal at the edge of ingot without PED treatment is much longer than thatwith PED, and (2. the perlite lamellae of steel billets after deposed by PED are twisted and shortened. An explanation of those experimental results is given.

关键词： electro-pulse solidification structure steel ingot

Performance Modeling and Approximate Analysis of Multiserver Multiqueue Systems with Poisson and Self-similar Arrivals

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Journal of university of science and {2. beijing 2001年第2期8卷 145-151页

作者： Zhiguang Shan, Chuang Lin, Yang Yang, Yan Wang (Information Engineering school, university of {2. and technology beijing, beijing 100083, china. (Department of Computer {2. and technology, Tsinghua university, beijing 100084, china. Information Engineering school University of Science and Technology Beijing 100083 China

The problem of state space explosion is still ran outstanding challenge in Markovian performance analysis for multiserver multiqueue (MSMQ) systems. The system behavior of a MSMQ system is described using stochastic high-level Petri net (SHLPN) models, and an approximate performance analysis technique is proposed based on decomposition and refinement methods as well as iteration technique. A real MSMQ system, Web-server cluster, is investigated. The performance of an integrated scheme of request dispatching and scheduling is analyzed with both Poisson and self-similar request arrivals. The study shows that the approximate analysis technique significantly reduces the complexity of the model solution and is also efficient for accuracy of numerical results.

关键词： multiserver multiqueue (MSMQ) system Web-server cluster performance analysis stochastic high-level Petri net (SHLPN) request dispatching request scheduling

An Improved Artificial Neural Network Model for Predicting Silicon Content of Blast Furnace Hot Metal

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International Journal of Minerals,Metallurgy and Materials 2000年第4期14卷 269-272页

作者： Bin Yao, Tianjun Yang, Xiaojun Ning (Metallurgy school, university of {2. and technology beijing, beijing 100083, china. Metallurgy school University of Science and Technology Beijing Beijing 100083 China

Based on the skills of initializing weight distribution, adding an impulse in a neural network and expanding the ideal of plural weights, an artificial neural network model with three connection weights between one and another neural unit was established to predict silicon content of blast furnace hot metal. After the neural network was trained in the off-line state on the basis of a large number of practical data of a commercial blast furnace and making many learning patterns, satisfactory testing and simulating results of the model were obtained.

关键词： blast furnace silicon content neural network Metallurgy

Behaviors of fine bubbles in the shroud nozzle of ladle and tundish

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Journal of university of science and {2. beijing 2003年第4期10卷 20-23页

作者： Yanping Boo, Jianhua Liu, and Baomei XuMetallurgical Engineering school, university of {2. and technology beijing, beijing 100083, china Metall. Eng. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

Fine bubbles will create when the inert gas is introduced to the high rapidsteel stream within the shroud nozzle between ladle and tundish. The collision and attachment amongthe bubbles and fine inclusions will promote the floatation efficiency of inclusions in the *** behaviors of the bubbles, such as the dispersion in shroud, coalescence and floatation intundish, are studied. The results show that the maximum sizes of the bubbles in the water and steelflow within the shroud in the length of 1.2.m are 0.70-1.44 mm and 1.53-3.16 mm respectively whenthe flow rates are 0.006-0.016 m^3/s; the terminal velocities of fine bubbles in the water andmolten steel within the tundish are 0.02.0.2.and 0.05-0.6 m/s.

关键词： fine bubbles shroud nozzle of the ladle flotation

Solubility of Ba in Liquid Iron and Interaction Effect of the Third Elements

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International Journal of Minerals,Metallurgy and Materials 2000年第2期14卷 82-85页

作者： Bo Song Qiyong Han chenming Zhang(Metallurgy school, {2. of science and technology beijing, beijing 100083, china. Metallurgy school University of Science and Technology Beijing Beijing 100083 China

Experiments were carried out at 1873 K in a double-temperature zone furnace using vapor pressure method. The equilibriumtests of bedum vapor with liquid iron were conducted in CaO crucibles sealed in a Mo chamber. As a result, the experiments obtainedthe relation between the dissolved content of Ba in liquid iron and the vapor pressure of Ba and the standard Gibbs energies for the re-actions Ba(g)=[Ba] and Ba(l)=[Ba].

关键词： Ba dissolution equilibrium liquid iron interaction parameter

Physical Property Influence on Foaming Index of Refining Slag

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International Journal of Minerals,Metallurgy and Materials 1999年第1期13卷 8-10,14页

作者： Lin Di Ping Wang Jie Fu (Metallurgy school, university of {2. and technology beijing, beijing 100083, china. Univ of science and technology Beijing Beijing China

The foaming indexes of a group of refining slag were measured. The refining slag with better foaming ability was chosen,its composition (mass frachon in %) is CaO, 53.2., SiO2. 17.75, MgO, 9; Al2.3, 15 and CaF2. 5. The relationship between slag foaming index and physical properties of the slag was obtained by dimensional analysis, and the expression indicates that viscosity of slag is the most important factor which influences foamng index. The influence sequence of slap composition on foaming index was also obtained as follows: CaF2.MgO→Al2.3→ B (CaO/SiO2..

关键词： secondary refining submerged arc slag dimensional analysis

Design and Synthesis of Ti-ZrO_2.Functionally Graded Materials

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Journal of university of science and {2. beijing 2001年第1期8卷 48-52页

作者： Lidong Teng, Fuming Wang, Wenchao Li Metallurgy school, university of {2. and technology beijing, beijing 100083, china Metallurgy school Univ. of Sci. and Technology Beijing Beijing 100083 China

Functionally graded materials (FGMs) based on titanium-zirconia system have been prepared by powder metallurgical method. The graded interlayer number and the compositional distribution have been designed by elastic finite element method. The interfacial microstructure between layers, the combining state of phases between Ti and ZrO2.have been investigated by means of XRD (X-ray diffraction), SEM (scanning electron microscope), EDS (energy dispersive spectrometer) and so on. The co-existing region of Ti and ZrO2.has been determined by thermodynamic calculation to control the sintering atmosphere. The experimental results show that the joint between Ti and ZrO2.phases is physical in this composite and ZrO2.mainly exists as tetragonal phase. The microstructure of Ti-ZrO2.system FGM exhibits a transition from a zirconia particle dispersion in a titanium matrix to an inverse dispersion of titanium in zirconia. The gradient structure of titanium and zirconia can relieve thermal stress.

关键词： Ti-ZrO2.system functionally graded material thermodynamic analysis finite element method

NONEL High Precision MS Delay Detonator

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Journal of university of science and {2. beijing 2001年第3期8卷 164-166页

作者： Daze Lin, Peng Yang Civil and Environmental Engineering school, university of {2. and technology beijing, beijing 100083, china Civil and Environmental Eng. school Univ. of Science and Tech. Beijing Beijing 100083 China

The NONEL high precision MS Delay Detonator (FDG-1detonator) is introduced. The main aspects about the FDG-1 detonator include the choice of structure, delay composition, control of the gas chamber, optimum charge and density, suitable explosives per meter in the NONEL tube, base firing charge and the main specifications. The improvement of the characteristics of FDG-1 detonator has been tested systematically. The testing method is reliable and its precision can meet the demand for usage.

关键词： NONEL high precision MS Delay Detonator delay time

Threshold quantum secure direct communication without entanglement

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science china.Physics,Mechanics & Astronomy) 2008年第2期51卷 176-183页

作者： YANG YuGuang1,3 & WEN QiaoYan2.1 College of Computer science and technology, {2. university of technology, {2. 10002., china.2.school of science, {2. university of Posts and Telecommunications, {2. 100876, china.3 State Key Laboratory of Information Security (Graduate school of Chinese Academy of sciences), {2. 100049, china College of Computer science and technology Beijing University of Technology Beijing China State Key Laboratory of Information Security (Graduate school of Chinese Academy of sciences) Beijing China school of science Beijing University of Posts and Telecommunications Beijing China

For the first time, a threshold quantum secure direct communication (TQSDC) scheme is presented. Similar to the classical Shamir's secret sharing scheme, the sender makes n shares, S1, …, Sn of secret key K and each receiver keeps a share secretly. If the sender wants to send a secret message M to the receivers, he en-codes the information of K and M on a single photon sequence and sends it to one of the receivers. According to the secret shares, the t receivers sequentially per-form the corresponding unitary operations on the single photon sequence and ob-tain the secret message M. The shared shares may be reusable if it can be judged that there is no eavesdropper in line. We discuss that our protocol is feasible with current technology.

关键词： quantum secure direct communication threshold secure direct communication quantum secret sharing