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THE CHARACTERISTICS OF THE PRESSURELESS SINTERED Si_3N_4-MgO-Ce0_2 CERAMICS

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Journal of Wuhan univ.rsity of Technology(Materials Science) 1996年第4期11卷 1-6页

作者：杨海涛杨国涛汤宇凌袁润章 Research Inst.for Advanced Mater..Wuhan univ.of Tech..Wuhan 430070.China central south univ.of Technology

An investigation of the pressureless sintering of Si3N4 with MgO-CeO2 revealed that MgO-CeO2 is a most effective sintering aid for silicon nitride. The amount of MgO-CeO2 and sintering conditions have a strong influence on the densification behaviour and mechanical properties of the sintered materials. The effect of the additive and sintering conditions are discussed. The silicon nitride pressureless sintered with MgO-CeO2 retained a relative density of 98. 5% and a bending strength of 950 MPa. The Si-Mg-Ce-O-N system is of great value for application and theoretical study.

关键词： ceramics silicon nitride sintering

A PRELIMINARY APPROACH TO THE GEOTECTONIC EVOLUTION HISTORY AND MINERLIZATION IN VICTORIA, AUSTRALIA

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Geotectonica et Metallogenia 2001年第1期25卷 37-44页

作者： DAI Ta-gen and CHEN Gua da (Dept. of Geology, central south univ., Changsha 410083, China) Dept.of Geology Central South Univ.Changsha410083China

According to the available data and field research, based on the diwa theory, the authors have studied the geotectonic evolution history and the associated minerlization in the Victoria area. It has been shown that this area is in fact a part of the Lachlan diwa region. The Victoria area can be divided into geodome fault fold zone and subsidence zone. The former can be subdivided into three zones, from west to east, which are western uplift zone, central depression zone and eastern uplift zone. The evolution history of the Victoria area can be divided into four stages——Pregeosyncline, geosyncline, plateform and diwa. Each stage has distinct sedimentary, magmatic and structural features. Of the four stages, diwa stage is the most important for minerlization. Diwa stage started in the Devonian. During the development of diwa, a number of granites, which are characterized by high SiO 2 and Na 2O+K 2O, were formed. The granites were abundance with mineral forming material. On the other hand, diwa geotectonism reformed and enriched the geosynclinal or platform ore deposits. Therefore, most of the ore deposits that occurred in the Victoria area are, more or less, related with diwa tectonism.

关键词： Diwa theory minerlization geotectonics Victoria

A STUDY ON THE GEOLOGICAL FEATURES AND GENESIS OF THE LONGSHAN Au-Sb DEPOSIT

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Geotectonica et Metallogenia 2002年第1期26卷 82-88页

作者： HU Xiang zhao and YANG Zhong bao(Dept. of Geology, central south univ., Changsha 410083, China) Dept. of Geology Central South Univ. Changsha 410083 China

The geological features of the Longshan Au Sb deposits are systematically described. Mineralization conditions, sources of ore materials and metallogenetic mechanism are also analysed according to sulfur,oxygen isotope composition, pyrite typomorphic features and fluid inclusion thermometry dating, The results show that it is a sedimentary metamophic hydrothermal deposit.

关键词： Geological feature Au-deposit genesis Longshan

THE ROLE OF MgO-CeO_2 IN THE DENSIFICATION OF Si_3N_4

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Journal of Wuhan univ.rsity of Technology(Materials Science) 1996年第3期11卷 1-7页

作者：杨海涛杨国涛袁润章 WUHAN univ.TECHNOL ADV MATER RES INSTWUHAN 430070PEOPLES R CHINA CENT S univ.TECHNOL GUANGZHOU 510641PEOPLES R CHINA

An investigation of the pressureless sintering of Si3N4 with MgO-CeO2 reveals that MgO-CeO2 is a much more effective sintering aid for silicon nitride than either MgO or CeO2. The amount of MgO-CeO2 and MgO/CeO, weight ratio has a strong influence on the densification be-haviour and mechanical properties of the sintered materials. The silicon nitride pressureless sintered with MgO-CeO2 re-tains a relative density of 98. 5% , a bending strength of 950 MPa. The Si-Mg-Ce-O-N system is of great value for appli-cation and theoretical study.

关键词： Si3N4 densification MgO-Ce()2 ce- ramics

GLOBAL ATTRACTIVITY IN A DELAY LOGISTIC DIFFERENCE EQUATION

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Applied Mathematics(A Journal of Chinese univ.rsities) 2003年第1期18卷 53-58页

作者： Zhou YinggaoDept. of Appl.Math.and Appl.Software,central south univ.,Changsha 410083,China. Dept. of Appl. Math. and Appl. Software Central South Univ. Changsha China

This paper studies the global attractivity of the positive equilibrium 1 of the delay logistic difference equation Δ y n=p ny n(1-y τ(n) ), n=0,1,2,...,(*)where {p n} is a sequence of positive real n... 详细信息

关键词： global attractivity positive solutions logistic delay difference equation.

冲击载荷下脆性岩板损伤断裂演化的实验模拟研究

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四川大学学报（工程科学版） 2011年第6期43卷 85-90页

作者：汪亦显曹平尹土兵中南大学资源与安全工程学院湖南长沙410083

在矿山运输系统中,井壁围岩冲击损伤破坏对经济和安全效益的影响是至关重要的,因为动态冲击载荷对井壁围岩和支护结构会产生严重的削弱破坏作用,室内研究表明,岩石样品如岩板在动态载荷的冲击作用下会失效。为研究在低速冲击载荷作用下... 详细信息

在矿山运输系统中,井壁围岩冲击损伤破坏对经济和安全效益的影响是至关重要的,因为动态冲击载荷对井壁围岩和支护结构会产生严重的削弱破坏作用,室内研究表明,岩石样品如岩板在动态载荷的冲击作用下会失效。为研究在低速冲击载荷作用下,脆性岩石损伤断裂的演化过程,利用分离式霍普金森压杆(SHPB)装置中压缩气体发射球体子弹对脆性岩板进行变角度冲击损伤实验,岩板受到冲击后,边缘出现凹坑,表面裂纹从撞击凹坑直达岩板边缘,实验中样品的表面裂纹能有效代表试样内部的开裂状况,能有效反映冲击能量的耗散、破裂区面积与裂纹表面积随入射能量呈非线性增长趋势,同时与入射角度相关,但当破裂区面积急剧下降时,裂纹表面积反而急剧上升,表明裂纹的发生发展有明显的孕育期,在入射能量达到临界值前,主要表现为裂纹孕育增长,在达到临界值后,发生宏观断裂破坏,裂纹面积呈负增长,破裂区面积增大。实验结果分析表明在实际工程中,围岩和支护结构的抗冲击的最优化设计角度范围在15°～30°。

关键词：冲击载荷岩板实验模拟损伤断裂

Research on the Financial Input of S＆T in Minority Areas based on the Elasticity Analysis

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Research on the Financial Input of S＆T in Minority Areas ba...

具有自适应残差补偿的神经网络预报模型设计与应用

第六届（2011）中国管理学年会——公共管理分会场

作者： Li Hong-Ling 1,Fang Chao2 (1 College of Public Management, south-central univ. for Nationalities, Institute of Rural Development in Minority Areas of SCUN, Wuhan , Hubei, 430074) (2 College of Public Management, south-central univ. for Nationalities, Wuhan , Hubei, 430074)

By the method of elasticity analysis, the article researches the financial input of S＆T in the minority areas during 2000 to 2008. It shows that the scape of input is not stable but changes dramatically and a part of the index is negative. This shows that the local government has not realized the importance of S＆T enough. But during this period, all the elasticity indexes is becoming more and more centralized. This shows the input mechanism is getting better. The paper claims that it is necessary for the local administrators to realize the importance of S＆T;to establish rules or laws for the S＆T input, to widen the way of getting S＆T fund and to improve the efficiency of using the financial input of S＆T.

关键词： Ethnic Minority Areas Elasticity Index Financial Input of S&T Gross Domestic Product(GDP)

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四川大学学报（工程科学版） 2003年第5期35卷 115-118页

作者：邵义元胡志坤鄂州大学教育系湖北鄂州436000 中南大学物理科学与技术学院湖南长沙410083

在对样本数据进行预处理的基础上,建立一个具有自适应残差补偿的改进BP神经网络动态预报模型,并对神经网络的学习参数进行自适应调整。将该模型应用于铜锍吹炼过程所需的氧气量进行预报。仿真结果表明,预报最大相对误差为3.97%,最小相... 详细信息

在对样本数据进行预处理的基础上,建立一个具有自适应残差补偿的改进BP神经网络动态预报模型,并对神经网络的学习参数进行自适应调整。将该模型应用于铜锍吹炼过程所需的氧气量进行预报。仿真结果表明,预报最大相对误差为3.97%,最小相对误差可以达到0.11%。该模型已应用于实际生产,具有精确度高、实用的优点。

关键词：铜锍吹炼样本预处理神经网络预报模型自适应残差补偿

推动与阻碍——美国对经济全球化进程的双重影响

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深圳大学学报（人文社会科学版） 2004年第6期21卷 47-53页

作者：刘胜湘中南财经政法大学国际问题研究所湖北武汉430060

美国是当今世界最强大的国家,在经济全球化进程中占有非常重要的地位,其对全球化进程的影响是深远而重大的,这些影响在很大程度上是美国内外政策造成的结果。归纳起来,美国对全球化的影响主要集中为助全球化和逆全球化。这两个方面鲜明... 详细信息

美国是当今世界最强大的国家,在经济全球化进程中占有非常重要的地位,其对全球化进程的影响是深远而重大的,这些影响在很大程度上是美国内外政策造成的结果。归纳起来,美国对全球化的影响主要集中为助全球化和逆全球化。这两个方面鲜明地体现了美国在经济全球化进程中的双重角色。

关键词：美国全球化安全利益