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Future Trends of Deep Sea Bed Mining Technology

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International Journal of Minerals,Metallurgy and Materials 1999年第1期13卷 4-7页

作者： Yan Feng Haoran Li Wenming Zhang (Resources Engineering school, university of Science and Technology beijing, beijing 100083. China) Resources Engineering school University of Science and Technology Beijing Beijing 100083 China

The present status of deep sea bed mining technology for polymetallic nodules has been critically examined in light of its history of development the UNCLoS (the United Nation Convention on the Law of the Sea) regime and the current trends in *** critical technologies have been highlighted and the need for system integration underscored. The deep sea bed environment and the engineering challenge were presented and the necessary features of the deep sea bed mining system for commercial mining was analyzed. The key accomplishments, problems and future bends in research in the development of the mining system are also discussed. Finally, it points out that the technology gaps can be filled by the bine commercial mining is undertaken as a result of market conditions in its favor.

关键词： deep sea bed mining, UNCLoS TIS (Total Integrated System), polymetallic nodules mining system

Numerical simulation of strain localization and damage evolution in large plastic deformation using mixed finite element method

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Journal of university of Science and Technology beijing 2004年第3期11卷 273-277页

作者： Zhanghua Chen Jiajian Jin Jiumei Xiao Applied Science school, university of Science and Technology beijing, beijing 100083. China Applied Science school University of Science and Technology Beijing Beijing 100083 China

An investigation of computer simulation is presented to analyze the effectsof strain localization and damage evolution in large plastic deformation. The simulation is carriedout by using an elastic-plastic-damage coupling finite element program that is developed based onthe concept of mixed interpolation of displacement/pressure. This program has been incorporated intoa damage mechanics model as well as the corresponding damage criterion. To illustrate theperformance of the proposed approach, a typical strain localization problem has been simulated. Theresults show that the proposed approach is of good capability to capture strain localization andpredict the damage evolution.

关键词： strain localization mixed element truesdell stress rate material damage

One-Dimensional Fractal Curves and Fractal Dimension Determination

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International Journal of Minerals,Metallurgy and Materials 1998年第3期12卷 165-168页

作者： Qikai Li Yue Zhang Wuyang Chu(Applied Science school, university of Science and Technology beijing, beijing 100083. China) Applied Science school University of Science and Technology Beijing Beijing 100083 China

Various methods for evaluating the fractal curves were reviewed and simulated on computer. It is shown box-counting and power spectrum methods generally give poor measuring results, while yard and variation methods could obtain good results. However,owing to multiple influencing factors, further study needs to be done before widespread application of variation method. In order to improve the measuring accuracy of yard method, a new method has been propoed to measure the fractal dimension by changing the instrumental resolutions.

关键词： fractal fractal dimension computer simulation

Genetic Algorithm for the Thermal Stresses Optimum Design ofFunctionally Gradient Material Plate

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International Journal of Minerals,Metallurgy and Materials 1999年第3期13卷 224-227页

作者： Xiaodan Zhang Zhengbin Tang Changchun Ge(Applied Science school, university of Science and Technology beijing, beijing 100083. China) Applied Science school University of Science and Technology Beijing Beijing 100083 China

Based on the thermal stress distribution for functionally gradient material (FGM) plates, a Genetic Algorithm (GA) method for the thermal stresses optimum design of FGM plate with computer technologies is given. The m... 详细信息

关键词： functionally gradient material (FGM) thermal stress Genetic Algorithm (GA) crossover mutation

Field Investigation and FEM Analysis of Ground Subsidence in a Chinese Underground Gold Mine

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International Journal of Minerals,Metallurgy and Materials 2000年第1期14卷 1-4页

作者： Meifeng Cai Lan Qiao Bo Yu ChanghongLi Resources Engineering school, university of Science and Technology beijing, beijing 100083 Resources Engineering school University of Science and Technology Beijing Beijing 100083 China

Ground subsidence in a Chinese underground gold mine is remarkable. To find out reasons and regularities of the subsidence, following research work was carried out: (1) systemetical investigations of engineering geological conditions, including in situ stress sta- te, locstion and size of old river beds, ponds and unfilled mined-out areas, (2) in situ monitoring of strata movement by multi-point ex tensometers in 3.vertical boreholes; (3. FEM (Finite Element Method) analysis to study the relationship between the ground subsidence and mining excavation, especially to inspect the influence of unfilled mined-out areas at shallow depth on the subsidence. Based on the research results, measures to control the ground subsidence and to prevent buildings from damage are provided.

关键词： ground subsidence mining excavation regularities influencing factors, control measures.

Analysis for twinning and slip in face-centered cubic crystals under axisymmetric co-deformation

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Science China(Technological Sciences) 2006年第5期49卷 521-536页

作者： CHEN Zhiyong1,2, CAI Hongnian1, ZHANG Xinming2, WANG Fuchi1 & TAN Chengwen1,3.1. school of Material Science and Engineering, beijing Institute of Technology, beijing 100081, China 2. school of Material Science and Engineering, Central South university, Changsha 410083. China 3. school of Material Science and Engineering, beijing university of Aeronautics and Astronautics, beijing 100083. China 1. school of Material Science and Engineering Beijing Institute of Technology Beijing 100081 China 2. school of Material Science and Engineering Central South University Changsha 410083 China 3. school of Material Science and Engineering Beijing University of Aeronautics and Astronautics Beijing 100083 China

The maximum work principle of Bishop-Hill was developed to analyze the axisymmetric co-deformation in face-centered cubic crystals (f.c.c.) for twinning on {111} 112 and slip on {111} 110 systems. The influence of ξ , the ratio of critical re- solved shear stress for twinning to slip, on the yield stress states and corresponding active slip or/and twinning systems for orientations in the standard stereographic triangle of cubic crystal was investigated systematically. The Taylor factors and the anisotropy of yield strength for three important orientations [100], [110] and [111] in orientation space were analyzed. It is found that the yield strength asymmetry for the case of axisymmetric de- formation of tension and compression can be explained based on the microscopic theory of crystal plasticity. The concept of orientation factor for twinning ability was proposed and the deformation mechanism map in the orientation space was established for the case of axisymmetric deformation. The deformation texture formation and development of f.c.c. crystals with low stacking fault energy for axisymmetric tension can be explained qualita- tively on the basis of analyzed results.

关键词： twinning slip face-centered cubic crystals axisymmetric co-deformation Bishop-Hill maximum work principle yield strength anisotropy

H~∞ Theory and its Application to the Position of Rolling Mill Control System

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International Journal of Minerals,Metallurgy and Materials 1999年第3期13卷 230-233页

作者： Jie Dong Chaonan Tong Kaixiang Peng(Information Engineering school, university of Science and Technology beijing, beijing 100083. China) Information Engineering school University of Science and Technology Beijing Beijing 100083 China

The controller designed according to classical or modern control theory will not satisfy the performance requirements when the controlled object in industrial field can not be described by exact mathematical model or the disturbance of the controlled system. In order to make the controlled system stable and having good performance, H∞ control theory was put forward to solve this practical problem. Taking the position of a rolling mill as the controlled object, it was rectified by optimal engineering way. Then, three different plans were put forward according to Bang-Bang control, LQ control and H∞ control, respectively. The result of the simulation shows that the controller designed according to H∞ method whose robust performance and ability to restrain colors disturbance is satisfactory.

关键词： position control H~∞ control LQ control Bang-Bang controll

High Performance Speech Compression System

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Journal of university of Science and Technology beijing 2001年第3期8卷 229-233页

作者： Ke Liu, Zhichun Mu, Zhong Wang Information Engineering school, university of Science & Technology beijing, beijing 100083. China Univ Sci & Technol beijing Informat Engn Sch Beijing 100083 Peoples R China

Since Pulse Code Modulation emerged in 193., digitized speech has experienced rapid development due to its outstanding voice quality, reliability, robustness and security in communication. But how to reduce channel width without loss of speech quality remains a crucial problem in speech coding theory. A new full-duplex digital speech communication system based on the Vocoder of AMBE-1000(TM) and microcontroller ATMEL 89C51 is introduced. It shows higher voice quality than current mobile phone system with only a quarter of channel width needed for the latter. The prospective areas in which the system can be applied include satellite communication, IP Phone, virtual meeting and the most important, defence industry.

关键词： digital signal processing digital speech compression digital communication full-duplex coding rate

Geochemical characteristics and tectonic implications of HP-UHP eclogites and blueschists in southwestern Tianshan, China

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Progress in Natural Science:Materials International 2006年第6期16卷 624-632页

作者： AI Yongliang, ZHANG Lifei, LI Xuping and QU Junfeng (MOE Key Laboratory of Orogenic Belt and Crust Evolution, school of Earth and Space Sciences, peking university, {3. 100871, China school of Geosciences and Resources, China university of Geosciences, {3. 100083. China) [a]MOE Key Laboratory of Orogenic Belt and Crust Evolution School of Earth and Space Sciences Peking University Beijing China [b]school of Geosciences and Resources China University of Geosciences Beijing China

Four rock assemblages in correspondence with two different tectonic settings have been recognized in the NEE-SWW extending HP-UHP metamorphic belt in southwestern Tianshan, northwest China. Eclogite assemblage EC1 is geochemically akin to alkaline within-plate oceanic island basalt (OIB). EC2 shows affinity to enriched mid-oceanic ridge basalt (EMORB). Rare earth element (REE) and other immobile trace element characteristics of blueschist assemblage BS1 resemble those of normal mid-oceanic ridge basalt (NMORB). These three assemblages are likely formed on a seamount setting, and the prevalent presence of carbonate minerals and om-phacite quartzite stripes/gobbets suggests ancient pelagic sediments including marls are probably developed upon the basaltic seamount. Whereas the geochemical characteristics of BS2 assemblage are of volcanic arc basalt-type. The seamount with the pelagic sediments on it is brought into the subduction zone, and volcanic arc basalts formed on the active continental margin and trench sediments are eroded and enwrapped in the subducting mass, they are altogether subjected to high to ultrahigh pressure metamorphism and subsequent exhumation towards surface. The HP-UHP metamorphic belt is thus interpreted as a subduct ion-accretionary complex formed by tectonic juxtaposition and imbrication of seamount, seafloor, trench and volcanic arc sequences during oceanic crust subduction.

关键词： southwestern Tianshan HP-UHP metamorphic belt snbduction-accretion complex trace element geochemistry.