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Science china(Technological Sciences) 2005年第z1期48卷 1-17页

作者： LI Shihai1, LIAN Zhenzhong1,2.& J. g. Wang3.1. Institute of Mechanics, Chinese Academy of Sciences, beijing 100080, china {2., Chinese Academy of Sciences,{3., china 3. Tropical Marine Science Institute, National University of Singapore, Singapore 1192.0 Chinese Acad Sci Inst Mech Beijing 100080 Peoples R China Chinese Acad Sci Grad Sch Beijing 100060 Peoples R China Natl Univ Singapore Trop Marine Sci Inst Singapore 119260 Singapore

This paper studies the stability of jointed rock slopes by using our improved three-dimensional discrete element methods (DEM) and physical modeling. Results show that the DEM can simulate all failure modes of rock slopes with different joint configurations. The stress in each rock block is not homogeneous and blocks rotate in failure development. Failure modes depend on the configuration of joints. Toppling failure is observed for the slope with straight joints and sliding failure is observed for the slope with staged joints. The DEM results are also compared with those of limit equilibrium method (LEM). Without considering the joints in rock masses, the LEM predicts much higher factor of safety than physical modeling and DEM. The failure mode and factor of safety predicted by the DEM are in good agreement with laboratory tests for any jointed rock slope.

关键词： rock masses, slope stability, DEM simulation, block size effect, joints configuration effect, limit equilibrium method.

The regular representation and regular covariant representation of crossed products of Woronowicz C^(*)-algebras

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Science china Mathematics 2005年第9期48卷 1245-1259页

作者： ZHANg Xiaoxia~(1,2. & gUO Maozheng~(1,3. 1. school of Mathematical Sciences,Peking University,beijing 100871,{2. 2. Department of Mathematics,Yantai University,Yantai 2.4005,{2. 3. LMAM,Peking University,beijing 100871,{2. 1. school of Mathematical Sciences Peking University 100871 Beijing China 2. Department of Mathematics Yantai University 264005 Yantai China 3. LMAM Peking University 100871 Beijing China

In this paper,it is shown that the regular representation and regular covariant representation of the crossed products A×α g correspond to the twisted multiplicative unitary operators,where A is a Woronowicz C~*-algebra acted upon by a discrete group ***,it is also shown that the regular covariant C~*-algebra is the Woronowicz C~*-algebra which corresponds to a multiplicative ***,an explicit description of the multiplicative unitary operator for C(SU_q(2. )×α (?) is given in terms of those of the Woronowicz C~*-algebra C(SU_q(2. ) and the discrete group g.

关键词： multiplicative unitary operator, Woronowicz C*-algebra, crossed product.

Discovery of immune related factors in Fenneropenaeus chinensis by annotation of ESTs

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Progress in Natural Science:Materials International 2004年第1期14卷 48-55页

作者： SHEN Yaoqing 1,2. , XIANg Jianhai 1*, WANg Bing 1,2. , LI Fuhua 1 and TONg Wei 3.1. Experimental Marine Biology Laboratory, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 2.6071,{3. 2. g.aduate school of the Chinese Academy of Sciences, {2. 10003.,{3. 3. genomics & Bioinformatics Institute, Chinese Academy of Sciences, {2. 1013.0,{3.) Chinese Acad Sci Inst Oceanol Expt Marine Biol Lab Qingdao 266071 Peoples R China Chinese Acad Sci Grad Sch Beijing 100039 Peoples R China Chinese Acad Sci Geonom & Bioinformat Inst Beijing 101300 Peoples R China

A total of 10446 expressed sequence tags (ESTs) are obtained by a large scale sequencing of a cDNA library from cephalothorax of adult Fenneropenaeus chinensis . An EST analysis platform was built up based on local computers and bioinformatic techniques were used to annotate these ESTs in order to promptly find possible functional genes, especially for immune related factors. About 4% of the ESTs show similarity to the coding sequences of such factors, including lectin, serine protease, serpin, lysozyme, etc. These ESTs provide a partial profile of the immune system in F. chinensis and useful information for further study on these genes.

关键词： Fenneropenaeus chinensis bioinformatics ESTs immune factors

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,{3. 2. school of Science, {3. University of Posts and Telecommunications, {3. 100876,{3. 3. school of Mathematics and Statistics, Huazhong Normal University, Wuhan 43.079, Hubei,{3. Wuhan University School of Mathematics and Statistics Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***) beijing University of Posts and Telecommunications School of Science Beijing China (GRID:grid.31880.32) Huazhong Normal University School of Mathematics and Statistics Wuhan Hubei China (GRID:grid.411407.7) (ISNI:***)

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

A formal model of fair exchange protocols

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Science in china(Series F) 2005年第4期48卷 499-512页

作者： QINg Sihan1,2.3.& LI gaicheng1,2.3.1. Engineering Research Center for Information Security Technology, Institute of Software, Chinese Aca- demy of Sciences, beijing 100080,{3. 2. beijing Zhongke Ansheng Corporation of Information Technology, beijing 100080,{3. 3. g.aduate school of the Chinese Academy of Sciences, beijing 10003.,{3. 1. Engineering Research Center for Information Security Technology Institute of Software Chinese Academy of Sciences 100080 Beijing China 2. beijing Zhongke Ansheng Corporation of Information Technology 100080 Beijing China 3. g.aduate school of the Chinese Academy of Sciences 100039 Beijing China

Based on the study of existing fair exchange protocols, this paper sets up an accurate formal model by stepwise refinement. In the process of refinement an unreliable channel is employed to simulate an attack behavior. The model provides a novel formal definition of exchanged items, and presents the formal goals for fairness, accountability, etc., reflecting the inherent requirements for fair exchange protocols across-the-board. In order to check, prove, and design fair exchange protocols effectively and efficiently, the model puts forward a novel property of abuse-freeness which applies to all fair exchange protocols, gives a formal definition for trust strand of the third party, and presents general criteria of designing a secure and effective fair exchange protocol. Taking a typical fair exchange protocol as an example, this paper presents the analysis steps of fair exchange protocols appealing to our model. An unknown attack is uncovered. The analysis reveals the process of a complete attack, discovering deeper reasons for causing an attack. Finally, we modify the flawed protocol and the revised protocol ensures the desirable properties.

关键词： events local causal relation local temporal relation global relation exchanged item security goals.

A tentative study for the prediction of the CME related geomagnetic storm intensity and its transit time

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Science china(Technological Sciences) 2005年第6期48卷 648-668页

作者： ZHAO Xinhua1,2.& FENg Xueshang1,3.1. SIgMA Weather group, Key Laboratory of Space Weather, Center for Space Science and Applied Re-search, Chinese Academy of Sciences, beijing 100080, china {2. of the Chinese Academy of Sciences, beijing 10003., china 3. school of geophysics and geoinformation Systems, china University of geosciences, beijing 100083. china 1. SIgMA Weather group Key Laboratory of Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences 100080 Beijing China 2. g.aduate school of the Chinese Academy of Sciences 100039 Beijing China 3. school of geophysics and geoinformation Systems China University of Geosciences 100083 Beijing China

Using 80 CME-ICME events during 1997.1―2.02.9, based on the eruptive source locations of CMEs and solar magnetic field observation at the photosphere, a current sheet magnetic coordinate (CMC) system is established in order to study the propagation of CME and its geoeffectiveness. In context of this coordinate system, the effect of the eruptive source location and the form of heliospheric current sheet (HCS) at the eruptive time of CME on the geomagnetic storm intensity caused by CME and the CME’s transit time at the Earth is investigated in detail. Our preliminary conclusions are: 1) The geomagnetic disturbances caused by CMEs tend to have the so-called “same side-opposite side effect”, i.e. CMEs erupt from the same side of the HCS as the earth would be more likely to arrive at the earth and the geomagnetic disturbances associated with them tend to be of larger magnitude, while CMEs erupting from the opposite side would arrive at the earth with less probability and the corresponding geomagnetic disturbance magnitudes would be relatively weaker. 2. The angular separation between the earth and the HCS affect the corresponding disturbance intensity. That is, when our earth is located near the HCS, adverse space weather events occur most probably. 3. The erupting location of the CME and its nearby form of HCS will also affect its arrival time at the earth. According to these conclusions, in this context of CMC coordinate we arrive at new prediction method for estimating the geomagnetic storm intensity (Dstmin) caused by CMEs and their transit times. The application of the empirical model for 80 CME-ICME events shows that the relative error of Dst is within 3.% for 59% events with Dstmin≤?50 nT, while the averaged absolute error of transit time is lower than 10 h for all events.

关键词： coronal mass ejections, current sheet magnetic coordinate system, geomagnetic storm intensity, transit time, prediction method.

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,{3. 2. Institute of Computing Technology, Chinese Academy of Sciences, {2. 100080,{3. 3. g.aduate school of the Chinese Academy of Sciences, {2. 10003.,{3. school of Information Engineering Zhejiang Forestry College Hangzhou 311300 Zhejiang 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

Study on NDVI-T_s space by combining LAI and evapotranspiration

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Science china Earth Sciences 2006年第7期49卷 747-754页

作者： HAN Lijuan1,2.3. WANg Pengxin4, YANg Hua1,2.3. LIU Shaomin1,2.3.& WANg Jindi1,2.3.1. Research Center for Remote Sensing and gIS, school of geography, beijing Normal University, beijing 100875,{3. 2. State Key Laboratory of Remote Sensing Science, beijing 100875,{3. 3. beijing Key Laboratory for Remote Sensing of Environment and Digital Cities, beijing 100875,{3. 4. Department of Information Management, College of Information and Electronic Engineering,{3. Agricultural University, beijing 100083.{3. 1. Research Center for Remote Sensing and gIS School of Geography Beijing Normal University Beijing 100875 China 2. State Key Laboratory of Remote Sensing Science Beijing 100875 China 3. beijing Key Laboratory for Remote Sensing of Environment and Digital Cities Beijing 100875 China 4. Department of Information Management College of Information and Electronic Engineering China Agricultural University Beijing 100083 China

This paper focuses on interpreting the different spatial relationships between NDVI and Ts, a triangular or a trapezoid, and on analyzing transformation conditions, the physical and ecological meanings of the vegetation index-surface temperature space as well. Further, we use the Tempera-ture-Vegetation Dryness Index (TVDI) to explain the existent meaning of a triangular space after NDVI reaches its saturated state by employing the relationships between NDVI, LAI and evapotranspiration. The specific relations between NDVI and Ts are useful for describing, validating and updating land surface models.

关键词： NDVI, land surface temperature, evapotranspiration, leave area index.

A novel endorectal RF coil for high resolution MRI and spectroscopy of the prostate

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Progress in Natural Science:Materials International 2005年第5期15卷 472-476页

作者： ZHANg Hongjie 1,2. SONg Xiaoyu1, WANg Xiaoying3. XU Pingfang1 and BAO Shanglian1*(1. beijing Key Laboratory of Medical Physics & Engineering, Peking University, beijing 100871,{2. 2. Navy general Hospital, beijing 10003.,{2. 3. Peking University First Hospital, beijing 10003.,{2.) beijing Key Laboratory of Medical Physics & Engineering Peking University Beijing 100871 China Navy general Hospital Beijing 100037 China Peking University First Hospital Beijing 100034 China

The diagnosis of prostate diseases by magnetic resonance imaging (MRI) in vivo is sometimes difficult for the lower signal to noise ratio (SNR). To increase the SNR of the prostate image, we designed a RF coil that can be inserted into rectum and was named endorectal coil. The properties of RF coil were evaluated using a network analyzer. Moreover the images and spectroscopy of a special phantom were acquired and the results were compared to those of the commercial TORSO coil (g.E. Medical Systems, USA). Our coil gave a significantly higher SNR at the region of interest (ROI). The achieved high local SNR and resulting high spatial resolution would add more anatomic and biochemical information to the diagnosis of prostate diseases.

关键词： MRI RF coil endorectal coil.

Formal analysis and design of multi-party fair exchange protocols

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Science in china(Series F) 2006年第2期49卷 155-174页

作者： QINg Sihan1,2.3.& LI gaicheng1,3.1. Engineering Research Center for Information Security Technology, Institute of Software, Chinese Academy of Sciences, beijing 100080, china 2. beijing Zhongke Ansheng Corporation of Information Technology, beijing 100080, china 3. g.aduate school of the Chinese Academy of Sciences, beijing 10003., china 1. Engineering Research Center for Information Security Technology Institute of Software Chinese Academy of Sciences Beijing 100080 China 2. beijing Zhongke Ansheng Corporation of Information Technology Beijing 100080 China 3. g.aduate school of the Chinese Academy of Sciences Beijing 100039 China

Based on the origin of message items and channel combination between transacting parties, and events and relations among events, this paper presents a concise, precise, and hierarchical model for general fair exchange protocols, formally specifies various security requirements which are able to reflect inherent requirements for fair exchange protocols more rigorously, and partition these security requirements with fine granularity. This work helps analyze, debug, and design multi-party fair exchange protocols more effectively and elaborately,

关键词： fair exchange logical protocol formal model security requirement.