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Investigation of cold Rolling Texture and Recrystallization Texture in NiW Substrates

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稀有金属材料与工程 2011年第S3期40卷 329-333页

作者： Tian Hui, Suo Hongli, Qiu Huoqin, Liu Min, Ma Lin, Wang Limin, Yuan Dongmei, Wang Yingxia beijing university of Technology, beijing 10012., c.ina beijing Univ Technol Coll Mat Sci & Engn Beijing 100124 Peoples R China

NiW alloys were fabricated by cold isostatic pressing, the W content being 5, 7 and 9.3 at%, respectively. The NiW substrates were obtained by rolling assisted biaxially texturing. The cold rolling and recrystallization textures of NiW substrates were systematically studied by X-ray and EBSD, which revealed a variation of rolling texture in NiW substrates with increasing W content, which also influenced the copper (c) type and brass (B) type texture, as well as the transition between them. In addition, the recrystallization texture was influenced by the cold rolling texture. The main observations are: (1) Deformation twinning and orientation banding attributed to the cross slip and it is strongly related to the stacking fault energy which has a decisive effect on the texture transition from c to B type texture in NiW substrates with the W content increase. (2. The recrystallization cube texture is strongly related to the rolling texture. The c type texture was obtained in Ni5W substrates with 99% reduction, and was beneficial for the formation of the cube texture after recrystallization. The B type texture was obtained in Ni9W substrates with 99% reduction, and it was hard to obtain the cube texture, where a large number of annealing twins were formed during recrystallization process, leading to the formation of rotating cube texture, and thereby affecting the formation of sharp cube texture in Ni9W substrate.

关键词： NiW alloy cold rolling texture c type texture B type texture recrystallization texture

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抽吸式自然对流换热的实验研究

太阳能学报 1992年第3期13卷 250-254页

作者：韩振兴陆维德邹文煜刘全红北京航空航天大学北京100083 北京市太阳能研究所北京100083

用稳态法进行了等温竖直平行平板间抽吸式自然对流换热的实验研究。着重研究了温差及间距对换热的影响,发现小间距及大间距有不同的换热规律。实验数据具有较高的精度,建立的经验公式在d/L=0.02.-0.2.、Ra_d=500-1.5×10~6的范围内,换... 详细信息

用稳态法进行了等温竖直平行平板间抽吸式自然对流换热的实验研究。着重研究了温差及间距对换热的影响,发现小间距及大间距有不同的换热规律。实验数据具有较高的精度,建立的经验公式在d/L=0.02.-0.2.、Ra_d=500-1.5×10~6的范围内,换热系数的相对误差不大于±12.。

关键词：抽吸式自然对流换热实验采暖

Emergency access mechanism in IEEE 802.15.4 for wireless body area sensor networks

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The Journal of c.ina Universities of Posts and Telecommunications 2009年第6期16卷 24-31页

作者： GUO Yan-yan,KANG Gui-xia,cAO Yu,ZHANG Ping Key Laboratory of Universal Wireless communications,Ministry of Education,beijing university of Posts and Telecommunications,beijing 100876,c.ina [a] Key Laboratory of Universal Wireless communications Ministry of Education beijing university of Posts and Telecommunications beijing 100876 c.ina

IEEE 802.15.4 protocol has attracted much attention in research and industrial communities as candidate technology for wireless body area sensor networks（WBASNs）.IEEE 802.15.4 supports the exclusive use of a wireless channel through guaranteed time slot（GTS）.However,on one hand,bandwidth underutilization rate may be lower because of the variance between the guaranteed bandwidth and the arrival *** the other hand,the waiting time for transmitting emergency notification is getting longer when the GTSs assigned to the nodes increase in *** solve these problems,in this article,a new scheme is proposed to reduce transmission delay for the alarm notification in emergent *** results are presented to validate the efficiency of the proposed scheme by comparing it with the medium access control（MAc） protocol of IEEE 802.15.4.

关键词： WBASN GTS IEEE 802.15.4 emergency mechanism

THE cRUSTAL STRUcTURE BENEATH THE EASTERN QINGHAI

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地学前缘 2000年第S1期7卷 289-289页

作者： Wang Youxue 1, A. Hirn 2. A.Galve\+2. Jiang Mei 3[WT5,5”BX](1 c.ina university of {2.,beijing 100083,c.ina 2.Laboratoire de Sismologie Experimentale, IPG,Paris,France 3.chinese Academy of {2.,beijing 100037,c.ina)

A Sino\|French joint wide\|angle seismic reflection survey was conducted in eastern Qinghai Province of P. R. c.ina in 1998. There are several geological units in this region, including Sanjiang Fold belt, Bayan Har fold belt, eastern Kunkun fold belt, western Qingling fold belt, Qaidam basin and Qilian fold belt. The seismic data acquired in the seismic experiment provides an abundant information and reveals the detailed crustal velocity structure and differences between all the tectonic units in this region. These results will help us to understand the evolution procedure and mechanism of the formation of Qinghai—Xizang *** to the seismic data, several reflection phases were identified. After the phase correlation, the reflectivity method and Dynamic Ray Tracing were applied simultaneously to model the 1\|D velocity structure for different tectonic units, actually to determine the velocity distribution within the crust. Based on the 1\|D depth\|velocity function, keeping the layer\|velocities fixed and only adjusting the shape of the reflectors to fit the observed data by Dynamic Ray Tracing, the 2.|D crustal velocity structures were established for each tectonic unit. The results show that there are some obvious differences between Sanjiang and Bayan Har. The crust is about 76km thick with an average velocity of 6 33km/s in Sanjiang region, but about 64km with an average velocity of 6 2.km/s in Bayan Har. On the other hand, the velocity of lower crust in Sanjian is lower (about 6 65km/s) than in Bayan Har (about 6 90km/s), and the thickness of the lower crust in Sanjiang is much thicker than in Bayan Har. A low velocity layer ( v p=5 80～5 85km/s) exists on both sides of Jinsha fault. These evidences indicate the existence of Jinsha suture.

关键词： seismic data Moho reflections crust eastern Qinghai

A Study of Reform in Linear System Theory Teaching

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A Study of Reform in Linear System Theory Teaching

Three-dimensional critical slip surface locating and slope stability assessment for lava lobe of Unzen volcano

第三届教学管理与课程建设学术会议

作者： Bingji XU 1 , Hui cHENG 1,2.1 Schoole of Information Engineering, c.ina university of {2., beijing ,c.ina 2.Schoole of Mechanical and Electronic Engineering, chizhou university, chizhou, Anhui, c.ina

The linear system theory is a professional course in the control science and engineering field and the course has a strong theoretical and abstraction, how can we let the students to grasp this course more easily and learn to use the knowledge to solve the problem in the control areas is the original intention of this teaching reform in the linear system theory. Analysis by the features of the course and the students’ learning ability, our electrical and automation laboratory decided to bring in the linear triple stage inverted pendulum as the experimental platform for teaching reform, through design, discussion, testing and summary the control scheme of the experimental platform to help the student understand the course more easily, at the same time also stimulate the students’ independent innovation thinking.

关键词： Linear System Theory Education Reform Linear Triple Stage Inverted Pendulum

来源： cnki会议评论

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Journal of Rock Mechanics and Geotechnical Engineering 2011年第1期3卷 82-89页

作者： Mowen Xie,Zengfu Wang,Xiangyu Liu,Bo Xu School of civil and Environmental Engineering,university of Science and Technology beijing,beijing,100083,c.ina School of civil and Environmental Engineering university of Science and Technology beijing{2. c.ina

Even Unzen volcano has been declared to be in a state of relative dormancy,the latest formed lava lobe No.11 now represents a potential slope failure mass based on the latest *** paper concentrates on the stability of the lava lobe No.11 and its possible critical sliding *** proposes geographic information systems (GIS) based three-dimensional (3D) slope stability analysis *** uses a 3D locating approach to identify the 3D critical slip surface and to analyze the 3D stability of the lava lobe *** the same time,the new 3D approach shows the effectiveness in selecting the range of the Monte carlo random variables and locating the critical slip surface in different parts of the lava lobe *** results are very valuable for judging the stability of the lava lobe and assigning the monitoring equipments.

关键词： three-dimensional (3D) slope stability limit equilibrium equation Unzen volcano lava lobe geographic information systems (GIS)

The Absolute and convective Secondary Instabilities in the conduction Regime

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communications in Nonlinear Science and Numerical Simulation 1999年第1期4卷 34-38页

作者： Jianjun TAO and Dachun YAN (Dept. of Mechanics & Engineering Sciences,Peking university, beijing 100871,{2.) Dept. of Mechanics & Engineering Sciences Peking University Beijing 100871 China

convective and absolute instabilities in the conduction regime of a vertical heated slot are investigated. It is found that in a large range of Prandtl number (0 12. a secondary instability appears with stationary mo... 详细信息

convective and absolute instabilities in the conduction regime of a vertical heated slot are investigated. It is found that in a large range of Prandtl number (0 2.00) different instability mode has different characteristics: the stationary mode is absolute instability while the traveling wave mode is convective instability. When Pr > 12. a secondary instability appears with stationary mode, and it is proven that even at large Prandtl numbers the stationary mode still exists.

关键词： absolute instability convective instability conduction regime

Effect of Aging Temperature on Stress corrosion cracking of 17-4 PH Stainless Steel in Wet H_2. Environment

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稀有金属材料与工程 2012年第S1期41卷 219-222页

作者： Zhou chengshuang,Zheng Shuqi,chen changfeng,Lu Guiwu c.ina university of Petroleum,{2. 102.49,c.ina c.ina Univ Petr Dept Mat Sci & Engn Beijing 102249 Peoples R China

The effect of aging temperature on stress corrosion crocking of 17-4 precipitation-hardened(PH)stainless steel in simulated stimulant oil well environment was studied by the method B-NAcE standard bent-beam *** is found that when aging temperature ranges from 480 to 610℃,the sensitivity of hydrogen embrittlement decreases significantly.

关键词： stress corrosion crocking(SSc) aging temperature 17-4 precipitation-hardened stainless steel hydrogen embrittlement

Active Suspension control Design & Simulation Based on Backstepping

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微计算机信息 2009年第13期 224-226页

作者： (Mechanical Engineering School of university of Science & Technology beijing,beijing 100083,c.ina) cHEN Bing ZENG Ming YIN Zhong-jun

Vehicle suspension system is a typical nonlinear *** control theory is applicable to control of nonlinear *** this article,an active suspension system model based on backstepping control strategy was *** was proved that the active suspension system posed property of global asymptotic stability and could reach the goal of avoiding suspension stroke when vehicle met a road *** research of a vehicle single tire suspension traveling over road bump was *** results demonstrated that performance of active suspension system with backstepping control strategy presented in the article was superior over active suspension with optimal control and passive suspension and avoided suspension stroke,when vehicle traveled over road bump.

关键词： Vehicle Active suspension Nonlinear Backstepping Simulation