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Formal Verification under Unknown Constraints

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Wuhan University Journal of Natural Sciences 2005年第1期10卷 43-46页

作者： LI Guang-hui 1,2.3., LI Xiao-wei 2.3.. School of Information Engineering, Zhejiang Forestry College, Hangzhou 3.13.0, Zhejiang, china 2. Institute of Computing Technology, chinese Academy of Sciences, beijing 100080, china 3. Graduate School of the chinese Academy of Sciences, beijing 10003., china School of Information Engineering Zhejiang Forestry College Hangzhou Zhejiang China Institute of Computing Technology Chinese Academy of Sciences Beijing China Graduate School of the chinese Academy of Sciences Beijing China

We present a formal method of verifying designs with unknown constraints (e.g., black boxes) using Boolean satisfiability (SAT). This method is based on a new encoding scheme of unknown constraints, and solves the corresponding conjunctive normal form (CNF) ***,this method can avoid the potential memory explosion, which the binary decision diagram (BDD) based techniques maybe suffer from, thus it has the capacity of verifying large designs. Experimental results demonstrate the efficiency and feasibility of the proposed method.

关键词： formal verification unknown constraints black box Boolean satisfiability Boolean comparison

Holocene grassland vegetation, climate and human impact in central eastern Inner Mongolia

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Science china Earth Sciences 2005年第7期48卷 1025-1039页

作者： HUANG Fei1, Kealhofer Lisa2. XIONG Shangfa3.& HUANG Fengbao1 1. Nanjing Institute of Geology and Paleontology,chinese Academy of Sciences,Nanjing 2.0008,{2. 2. Anthropology and Sociology Department,Santa Clara University,CA 95053.USA 3. Institute of Geology and Geophysics,chinese Academy of Sciences,{3. 10002.,{2. Nanjing Institute of Geology and Paleontology Chinese Academy of Sciences Nanjing 210008 China Anthropology and Sociology Department Santa Clara University CA 95053 United States Institute of Geology and Geoohysics Chinese Academy of Sciences Beijina 100029 China

Phytolith and pollen preserved in the Taipusi Banner paleosol profile, central eastern Inner Mongolia, provide evidence of Holocene grassland vegetation, climate and human impact. The combined phytolith and pollen records reveal a major change in vegetation composition about 5000 a BP. Before 5000 a BP, the vegetation was dominated by Aneurolepidium chinese-Stipa grandis grassland of C4 grasses. After 5000 a BP, C4 grasses rapidly retreated, indicating a shift to colder and more arid conditions. The gradual invasion of Stipa krylovii, Ag-ropyron desertorum, Ephedra, Chenopodiaceae and Caragana reveal the onset of grassland degeneration. Between 10000 and 872. a BP, the Aneurolepidium chinese-Stipa grandis grassland included a small proportion of Artemisia shrub and Echionopos type plants, implying a strong winter monsoon and very weak summer monsoon. From 872. to 7000 a BP, C4 grasses were common, indicating a strengthening of the summer monsoon. Between 7000 and 5000 a BP, the Holocene thermal maximum was evident, with a significant expansion of C4 grasses and the presence of some trees (such as Pinus and Betula, and so on) in or near the study site. From 42.0?000 a BP, a sandy grassland of Artemisia and Agropyron desertorum together with Aster-type taxa occurred. Precipitation amelioration took place between {2.00 and 2.70 a BP, with a rapid development of Echinops type plants and a small expansion of C4 grasses. From 2.70 a BP to present, human activities accelerated the process of grassland degeneration.

关键词： phytolith and pollen records grassland environment change human impact Holocene central eastern Inner Mongolia.

The crustal structure under Sanjiang and its dynamic implications:Revealed by seismic reflection/refraction profile between Zhefang and Binchuan,Yunnan

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Science china Earth Sciences 2005年第9期48卷 1329-1336页

作者： ZHANG Zhongjie1, BAI Zhiming1, WANG Chunyong2. TENG Jiwen1, Lü Qingtian3. LI Jiliang1, LIU Yifeng1 & LIU Zhenkuan4 1. Institute of Geology and Geophysics, chinese Academy of Sciences, {2. 10002., china 2. Institute of Geophysics, china Seismological Bureau, {2. 100085, china 3. Institute of Deposition Resource, chinese Academy of Geosciences, {2. 10003., china 4. School of Exploration and Information, china University of Geosciences, {2. 100083. china Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China Institute of Geophysics China Seismological Bureau Beijing China Institute of Deposition Resource Chinese Academy of Geosciences Beijing China School of Exploration and Information China University of Geosciences Beijing China

The fault belts in Sanjiang mainly include Jinshajiang-Honghe fault, Lancangjiang fault and Nujiang fault (called Sanjiang faults) in western Yunnan Province, china. By interpreting the wide-angle seismic reflection/refraction profile between Zhefang and Binchuan, which crosses Tengchong and Baoshan blocks in Dianxi (western Yunnan) tectonic zone, we recon- struct the crustal structure with seismic traveltime tomography for crustal P-wave velocity and the seismic scattering image for crustal seismic reflection structure. In this paper, we firstly present the crustal structure images of P-wave velocity and seismic reflection under the wide-angle seismic profile. These results demonstrate that, the crustal velocity structure and seismic reflec- tion structure along the profile can be divided into {2.segments, and there is an obvious difference of crustal structure among the eastern, the western and the middle segment. Generally, crustal P-wave velocities in the Baoshan segment are 0.1―0.2.km/s slower and seismic reflection am- plitudes from Moho discontinuity are stronger than the other 2.segments. In the studied area, crustal thickness is about 40 km, and shows the thickening tendency from west to east along the profile. Additionally, it can be seen that there is one strong-amplitude seismic reflection event as bright points at the depths of 8―10 km, along the segment of 80―115 km of the profile (south- ward of Tengchong); and seismic reflection wave-field from Moho discontinuity varies obviously along the lateral direction. Finally, we make some discussions on the crustal thickening pattern in the Sanjiang fault belt, structural environment of earthquake development and the contact rela- tionship between the Tengchong block, Banshan block and Luxi trough.

关键词： Sanjiang area wide-angle seismic profile crustal structure.

Two conceptual models of displacement transfer and examples

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Science china Earth Sciences 2005年第7期48卷 900-911页

作者： GUAN Shuwei1,2. WANG Xin2. YANG Shufeng2. HE Dengfa1 & ZHAO Weidong3.1. Research Institute of Petroleum Exploration and Development, beijing 100083. china 2. Department of Geosciences, Zhejiang University, Hangzhou 3.002., china 3. Tarim Oilfield Company, Korla 841000, china Research Institute of Petroleum Exploration and Development Beijing 100083 China Department of Geosciences Zhejiang University Hangzhou 310027 China Tarim Oilfield Company Korla 841000 China

This paper presents two conceptual models of displacement transfer, reverse sym- metry model and infinitely equal division model, based on the fault-bend folding theory. If the fault shape is held constant in the trend, then the distribution of slip magnitude, geometry of imbricate structures and its axial surface map all display reverse symmetry on the process of displacement transfer, as called reverse symmetry model in this paper. However, if the ramp height of thrust fault decreases gradually along its strike, the displacement is postulated to be equally and infinitely divided to every thrust that is formed subsequently, this kinematic process is described using infinitely equal division model. In both models, displacement transfer is characterized by the regular changes of imbricate thrusting in the trend. Geometric analysis indicates that the displacement transfer grads can be estimated using the tangent of deflective angle of hinterland structures. Displacement transfer is often responsible for the distortion and branching of the surface anticlines, especially in the region where the multi-level detachment structures is developed. We also present some examples from the frontal structures of the Southern Tianshan fold-and-thrust belt, Xinjiang,{2.. Displacement transfer between deep imbricate thrusts in the middle segment of Qiulitag anticline zone causes the Kuqatawu and Southern Qiulitag deep an- ticlines left-lateral echelon. The region, where these two deep anticlines overlap, is characterized by duplex structures, and extends about 18 km. The shallow anticline is migrated southward displaying obvious “S” form in this area.

关键词： displacement transfer fault-bend folding reverse symmetry model infinitely equal division model Qiulitag zone.

Some key technics of drop tower experiment device of National Microgravity Laboratory (china) (NMLC)

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Science china(Technological Sciences) 2005年第3期48卷 305-316页

作者： ZHANG Xiaoqian 1 , YUAN Longgen 1 , WU Wendong 1 , TIAN Lanqiao 2.& YAO Kangzhuang 2.1. Institute of Engineering Thermophysics, chinese Academy of Sciences, beijing 100080,{2. 2. Institute of Mechanics, chinese Academy of Sciences, beijing 100080,{2. Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing China Institute of Mechanics Chinese Academy of Sciences Beijing China

Drop tower is an important ground based facility for microgravity science experiment. The technical performances of the drop tower NMLC are advanced compared with similar facilities in the US, Germany and Japan. The main components such as drop capsule, deceleration devices, release mechanism present its advantages and creativities.

关键词： drop tower facility,drop capsule,deceleration devices,release mechanism.

Isotopic feature and uranium dating of the volcanic rocks in the Okinawa Trough

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中国科学：地球科学英文版 2006年第4期49卷 375-383页

作者： HUANG Peng1,2. LI Anchun1, HU Ningjing2.3. FU Yongtao1& MA Zhibang4 1. Institute of Oceanology, chinese Academy of Sciences, Qingdao 2.6071,{2. 2. Graduate School of the chinese Academy of Sciences, {3. 10003.,{2. 3. Institute of Soil Science, chinese Academy of Sciences, Nanjing 2.0008,{2. 4. Institute of Geology and Geophysics, chinese Academy of Sciences, {3. 10002.,{2. Institute of Oceanology Chinese Academy of Sciences Qingdao China Graduate School of the chinese Academy of Sciences Beijing China Institute of Soil Science Chinese Academy of Sciences Nanjing China Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China

Volcanic rocks from the northern and middle Okinawa Trough were dated by ura- nium-series dating method. Differential fractions using magnetic procedure were designed to separate samples. New report on the ages and isotopic data of rocks in the northern trough (especially black pumice) was discussed. Based on the uranium dates and Sr-Nd isotopic ratio, magmatic evolution process of the Okinawa Trough was noted. Firstly, there have been wide silicic volcanic activities in the Okinawa Trough from late Pleistocene to present, and the volcanic rocks can be divided into three subgroups. Secondly, magma generally came from PREMA source area under the Okinawa Trough. Magmatic evolution in the northern trough was similar to the middle, but different to the south. Finally, volcanic activities indicated that opening of the southern Okinawa Trough did not happen due to the collision between Luson Arc and Eurasian Plate until the early Pleistocene.

关键词： Okinawa Trough, black pumice, uranium-series dating, Sr-Nd isotopic ratio, magmatic evolution.

A high-resolution late Pleistocene record of pollen vegetation and climate change from Jingning, NW china

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Science china Earth Sciences 2006年第2期49卷 154-162页

作者： LI Chunhai12. TANG Lingyu1, FENG Zhaodong3.4, ZHANG Hucai2. WANG Weiguo3.& AN Chenbang3.1. Nanjing Institute of Geology and Palaeontology, chinese Academy of Sciences, Nanjing 2.0008, china 2. Nanjng Institute of Geography and Limnology, chinese Academy of Sciences, Nanjing 2.0008, china 3. Environment and Resources College, Lanzhou University, Lanzhou 73.000, china 4. beijing Normal University, beijing 100875, china Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing China Nanjng Institute of Geography and Limnology Chinese Academy of Sciences Nanjing China Environment and Resources College Lanzhou University Lanzhou China beijing Normal University Beijing China

With the support of 18 AMS-14C data, a high-resolution pollen record from the Suancigou section at Jingning, Gansu Province was established. Our results showed that the vegetation ex-perienced a series of changes characterized by the alternative growth and decline of forest and steppe components during the period from 44.2.to 11 ka B.P. in the Jingning area. Over the period of 44―2. ka B.P. (MIS3., coniferous forests were flourishing, indicating a humid climate with the tem-perature being lower than that of the present. Since 2.0}ka B.P., the vegetation was dominated by steppe-desert steppe under a cold and dry condition, and entered the Last Glacial Maximum domi-nated by desert steppe. Several periods of the marked decrease in the arborous pollen content in Suancigou well corresponded to the North Atlantic Heinrich events, especially to Heinrich event 3. further supporting that the Heinrich events were well reflected by the pollen record in the Loess Pla-teau as well.

关键词： Western Loess Plateau, pollen record, climatic change, late Pleistocene.

On the Symmetry Classes of Functions

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Wuhan University Journal of Natural Sciences 2005年第5期10卷 813-816页

作者： ZHU Ping~1,2. FAN Yun~3.1. School of Mathematics and Statistics, Wuhan University, Wuhan 43.072. Hubei,{2. 2. School of Science, beijing University of Posts and Telecommunications, beijing 100876,{2. 3. School of Mathematics and Statistics, Huazhong Normal University, Wuhan 43.079, Hubei,{2. School of Mathematics and Statistics Wuhan University Wuhan Hubei China School of Science Beijing University of Posts and Telecommunications Beijing China School of Mathematics and Statistics Huazhong Normal University Wuhan Hubei China

Let R be an integral domain of characteristic zero such that the corresponding group rings have block decompositions. We first prove that the submodule consisting of all the R-valued ξi-symmetric functions of several variables is a symmetry class, where ξi is any block character. Then we present a relationship among certain operators introduced for block character. Then we present a relationship among certain operators introduced for block characters. As a consequence, we obtain a decomposition of an arbitrary R-valued function of several variables. Finally, we describe the symmetry property of such summands and determine all the symmetry classes.

关键词： symmetry class strict symmetry class blockcharacter ξi-symmetric function block idempotent

Surface roughness and removal rate in magnetorheological finishing of a subsurface damage free surface

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Progress in Natural Science:Materials International 2005年第6期15卷 538-544页

作者： CHENG Haobo1*, WANG Yingwei2. FENG Zhijing1 and CHENG Kai3.1. State Key Laboratory of Tribiology, Tsinghua University, beijing 100084,{2. 2. Department of Material Sciences, Changchun University of Science and Technology, Changchun 13.02.,{2. 3. Faculty of Information and Engineering Systems, City Campus, Leeds LS1 3.E, UK) State Key Laboratory of Tribiology Tsinghua University Beijing 100084 China Department of Material Sciences Changchun University of Science and Technology Changchun 130021 China Faculty of Information and Engineering Systems City Campus Leeds LS1 3HE United Kingdom

Based on computer-controlled optical surfacing, a new technique called magnetorheological finishing (MRF), is presented. The new technique combines the features of conventional loose abrasive machining with a wheel shaped polishing tool. The tool incorporates a host of features and has unprecedented fabricating versatility. The pre-polishing and fine polishing processes can be performed only by adjusting different parameters. The material removal function is studied theoretically and the results of simulation present a Gaussian distribution feature. Based on the established theoretical model, material removal rate experiments involving a parabolic mirror are designed and carried out to determine the effect of controllable parameters on size of the gap between the workpiece and the polishing wheel, rotating speed of the polishing wheel, concentration of volume fraction of non-magnetic particles and polishing time. Further experiments are carried out on the surface microstructure of the workpiece, the final surface roughness with an initial value of 10.98 nm reaches 1.2. nm root mean square (RMS) after 2. min of polishing. The subsurface damage experiment and the atomic force microscopy (AFM) measurement on the polished surface can also verify the feasibility of the MRF technique.

关键词： magnetorheological finishing surface roughness computer controlled optical surfacing subsurface damage removal function.