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Prediction of Rock Burst with Deep Mining Excavation in Linglong Gold Mine

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Journal of University of Science and Technology Beijing 2001年第4期8卷 241-243页

作者： Meifeng Cai, Jinan Wang, Shuanghong Wang Civil and Environmental Engineering School, University of Science and Technology Beijing, Beijing 100083. china Civil and Environmental Engineering School University of Science and Technology Beijing Beijing 100083 China

To predict rock burst in deep mining excavation in Linglong gold mine, systematical laboratory tests of mechanical properties of rock, in situ stress measurement and 3-D FEM analysis on energy distribution in rock mass surrounding deep mining rooms were carried out. According to various prediction criteria of rock burst, it is concluded that rock burst is liable to occur during deep mining excavation in the mine.

关键词： rock burst prediction deep mining excavation Linglong gold mine

Cerium Oxide Film Prepared from Molten Salts

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Rare Metals 2001年第2期20卷 95-100页

作者： Xindong Wang, Guangming Liu, Yanfang Liu, Shuzhen Duan Department of Physical Chemistry, University of Science and Technology Beliing, Beliing 100083. china) 北京科技大学北京 100083.

Cerium oxide film formed on the nickel electrode at 453 K in LiNO3-KNO3 molten salts. The molten salt background and the cathode process of Leeds on the nickel electrode were studied by using cyclic voltammetry. The cathodic reaction mechanism of the molten salt background was: O-2(-)+e O-2(-2); O-2+2NO(3)(-) --> 2NO(2)(-)+2O(2). According to the results of SEM and XPS, cerium oxide film, which is composed of CeO2, can form on the nickel electrode at - 1.850 V vs. Ag/AgNO3 (0.1 mol/L) reference electrode.

关键词： cerium oxide low-temperature molten salts film

Effect of Preparation Condition on Low-density PS Particle Size and Distribution

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Journal of University of Science and Technology Beijing 2001年第4期8卷 274-276页

作者： Huili Fan, Jiemin Liu, Meijuan Wen, Weixue Tian Applied Science School. University of Science and Technology Beijing.Beijing 100083. china Applied Science School University of Science and Technology Beijing Beijing 100083 China

The preparation conditions were studied in order to obtain smaller, narrow size-distributed and low-density polystyrene (PS) micro-particles by suspension polymerization. The results show that some of preparation conditions, the shape and position of stirrers, and stirring rate etc., have important influence on the size and distribution of particles. The preparation conditions must be carefully designed and controlled in order to obtain high-quality PS beads. A bow-shaped stirrer is helpful to produce small-sized particles and narrow size distribution, and the upper edge of a stirrer should be set to the same level as the surface of mixture, and the stirring rate should be controlled in the range of 520-600 r/min.

关键词： low-density micro-particles suspension polymerization preparation conditions

Optimum Design of Movable Screen Jig Cycle

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International Journal of Minerals,Metallurgy and Materials 1999年第4期13卷 246-249页

作者： Chunbao Sun Yubo Sun(1 Resources Engineering School, University of Science and Technology Beijing, Beijing 100083. china2 Department of Mineral Engineering, Northeastern University. Shenyang 10006. china) Resources Engineering School University of Science and Technology Beijing Beijing 100083 China Department of Mineral Engineering Northeastern University Shenyang 110006 China

The basic method for designing and calculating reasonable jig cycle of movable screen jig was presented. The reasonabilityand reliability of designed jig cycle were verified by' means of the test on artificial mixed materials. An iron ore (12-100 mm) was treatedin tile TJD-75 model movable screen jig with the jig cycle. The good results were achieved. This would provide a reliable basis for designof commercial movable-screen jig.

关键词： movable-screen jig jig cycle optimum design

A New Method for Fractal Dimension Determination by STM at Nanometer Scale

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International Journal of Minerals,Metallurgy and Materials 1999年第1期13卷 64-68页

作者： Qikai Li Yue Zhang Wuyang Chu Chen Wang Chunli Bai (Applied Science School. University of Science and Technology Beijing, Beijing 100083. china)(Chemical Institute, Chinese Academy of Science, Beijing 100080. china) Applied Science School University of Science and Technology Beijing Beijing 100083 China Chemical Institute Chinese Academy of Science Beijing 100080 China

A new method for determining the fractal dimension by STM at nanomeler scale has been ***- Mandelbrot fractal curves were used to verify the accuracy and reliability. The Computer simulation showed that fractal dimen- sion obtained with this method generally outran the traditional yard method. The new method has been applied to the fractal dimension determination of the fractures of Ti3Al and Ti-24Al-11Nb alloys. The results show that the fractal dimension of Ti-24Al-11Nb alloy is higher than that of Ti3Al, and it varies with the crark extending orientation.

关键词： fractal dimension STM nanometer scale Ti-Al alloy

SEM In-situ Observation at Tensile Loading on Surface Inclusion in PM Rene95 Superalloy

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Journal of University of Science and Technology Beijing 2001年第4期8卷 286-289页

作者： Xiao Li, Lina Zhang, Jianxin Dong, Maicang Zhang, Yaohe Hu, Xishan Xie Materials Science and Engineering School. University of Science and Technology Beijing. Beijing 100083. china Materials Science and Engineering School University of Science and Technology Beijing Beijing 100083 China

The observation on crack initiation and propagation of surface inclusion Al2O3 in seeded PM Rene95 was conducted by SEM in-situ tension test. The results show that the cracks often initiate at the inclusion/matrix interface vertical to the applied stress direction, and easily propagate along the interface into the matrix. The interface of inclusion/matrix is just mechanically bounded on the base of SEM observation. The weak bonding of inclusion/matrix interface and stress concentration around inclusions are the main reasons of the matrix/inclusion interface debonding and local plastic deformation under the tensile loading in the in-situ tension test. Surface inclusion does not definitely lead to the failure of in-situ tension test. But the early surface crack initiation caused by ceramic inclusion is critically harmful to the LCF property of PM Rene95 superalloy, which can't be ignored.

关键词： inclusions SEM in-situ observation PM Rene95 stress concentration

Functionally Gradient Material Made by IncrementalMelting and Solidification Process

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International Journal of Minerals,Metallurgy and Materials 1999年第3期13卷 205-207页

作者： Chengchang Jia Hongbo Tian Tao Lin Zhimeng Guo Nobuyoshi Sasaki(Material Science and Engineering School. University of Science and Technology Beijing. Beijing, 100083. china)(CADIC Cooperation. Kawasaki, 213. Japan) Material Science and Engineering School University of Science and Technology Beijing Beijing 100083 China CADIC Cooperation Kawasaki 213 Japan

A new technique IMS (Incremental Melting and Solidification Process) has been introduced. A kind of cast steel high Mn foundry alloy gradient rnalerial was produced by this process. The microstructure and mechanical properties of the alloy were tested. Fe and Mn in the samples were measured by EPMA. The experimental results show that the content and hardness of Fe-Mn alloy vary continuously and the IMS process is an alternative way in producing metal matrix gradient material. It is possible for these materials to be made into some parts such as camshaft.

关键词： IMS process FGM melting solidification

Modal Analysis of Thread off Failure of Oil Round Thread Casing Connection

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Journal of University of Science and Technology Beijing 2001年第4期8卷 277-279页

作者： LiWang, Yong Zang, Zhaoneng Chen, Dechun Tong, Jiaxiang Zou 1) Shanahai Jiaotong University Shanghai 200030 china 2) Mechanical Engineering School. University of Science and Technology Beijing. Beijing 100083. china Shanghai Jiaotong University Shanghai 200030 China Mechanical Engineering School University of Science and Technology Beijing Beijing 100083 China

The dynamic modal model analysis of the oil casing connection is done by finite element method (FEM), and the first nature frequency, the second nature frequency, the vibration mode shape and the time domain of the node displacement and the element stress variation in the thread connection are gotten. The *** stresses of the connection in the static and dynamic state are also studied. The results of calculation and analysis show: (1) because the maximum of static stress is at the coupling thread end of connection, the connection begins to thread off at the coupling thread end, which is in accord with the results of the thread off experiment in laboratory; (2) because the first nature frequency is very high, the probability of casing connection to be damaged from vibration is little; (3) the shock dynamic load makes casing connection begin to thread off at the tube thread end.

关键词： API round thread casing connection modal analysis

CONTROLLED RELEASE FROM PDMAEMA GELS PREPARED BY GAMMA RADIATION

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Chinese Journal of Polymer Science 2002年第5期20卷 409-412页

作者： Ning Liu Min Yi Shuang-ji Chen Hong-fei Ha College of Chemistry and Molecular Engineering Peking University Beijing 100871, china Department of Biochemistry College of Applied Arts and Science, Beijing Union University Beijing 100083. china College of Chemistry and Molecular Engineering Peking University 北京 100871 Department of Biochemistry College of Applied Arts and Science Beijing Union University 北京 100083

Poly(N,N-dimethylaminoethyl methacrylate) (polyDMAEMA) hydrogels prepared by gamma-irradiation showed obvious temperature-sensitivity in a temperature range of 38-40degreesC and pH-sensitivity at pH=2.5. They also showed electric response behavior although it was not typical. The hydrogels were used in controlled release at different pH, temperature, and electric voltage. The release rates of methylene blue (MB) from the gels at 52degreesC and pH=1.24 were faster than those at 20degreesC and pH=10.56, respectively. In addition, the release rate at a field voltage of 5.0 was also faster than that without electric field.

关键词： poly(N,N-dimethylaminoethyl methacrylate) environmental sensitivity hydrogel controlled release