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Conjugate adjoining problem in braid groups and new design of braid-based signatures

science China(information sciences) 2010年第3期53卷 524-536页

作者： WANG LiCheng1,2. WANG LiHua2. CAO ZhenFu3, YANG YiXian1 & NIU XinXin1 information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing university of Posts and Telecommunications, Beijing 100876, China 2.ational Institute of information and Communications Technology, Tokyo 184-8795, Japan 3Trusted Digital Technology Laboratory, Shanghai Jiao Tong university, Shanghai 2.02.0, China 1. information Security Center State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China2. National Institute of Information and Communications Technology Tokyo 184-8795 Japan3. Trusted Digital Technology Laboratory Shanghai Jiao Tong University Shanghai 200240 China

The development of quantum computation casts serious threats to the securities of most existing public-key cryptosystems. Braid-based cryptography is one of the alternatives that have potential advantages in resisting quantum attacks. In this paper, the state of the art of braid cryptography is surveyed, and then a new cryptographic problem-conjugate adjoining problem related to braid groups is proposed. Based on this problem, we design a new braid-based signature scheme. This scheme is efficient and provably secure in the random oracle model. Further, we present the comparison between braid-based signatures and RSA-based ones. The signing process of the braid-based schemes is more efficient than that of RSA-based ones, while the verifying process of the braid-based ones is observably slow. Hence, braid-based signatures are suitable for scenarios where the signing process has to be as quick as possible but delays are permitted in the verifying process, for example, in off-line e-cash systems. The key sizes in braid-based schemes are considerably large-about 2. bits in the case of secret keys and 12. bits in the case of public keys. However, braid operations are much simpler and more efficient than modular exponential operations. Therefore, braid-based schemes can be embedded into devices with low computational ability and large memory space. The capability of braid cryptosystems to resist currently known quantum attacks is also discussed from the perspective of hidden subgroup problems.

关键词： braid group conjugate adjoining problem digital signature provable security resistance to quantum attack

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基于MOCCII多输入单输出n阶电流模式滤波器

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通信学报 2004年第2期25卷 138-143页

作者：王春华沈光地湘潭大学信息工程学院湖南湘潭411105 北京工业大学电子信息与控制工程学院和北京光电子技术实验室北京100022

提出了一种结构简单的基于MOCCIIn阶多输入单输出电流模式滤波器电路。该滤波器电路包含n+1个有源器件、n个电容及n+2.电阻,可以产生n阶低通、带通、高通、带阻电流模式滤波器。由于仅依靠改变外部输入电流信号的接入数目和方式来实现... 详细信息

提出了一种结构简单的基于MOCCIIn阶多输入单输出电流模式滤波器电路。该滤波器电路包含n+1个有源器件、n个电容及n+2.电阻,可以产生n阶低通、带通、高通、带阻电流模式滤波器。由于仅依靠改变外部输入电流信号的接入数目和方式来实现不同功能的滤波器,而电路内部结构及器件数目不变,所以该电路便于单片集成。文中对滤波器进行了PSPICE模拟。

关键词：多端输出的第二代电流传输器电流模式多输入单输出n阶滤波器

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Micro-geological causes and macro-geological controlling factors of low-resistivity oil layers in the Puao Oilfield

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Petroleum science 2009年第3期6卷 246-253页

作者： Tan Fengqi Li Hongqi Liu Hongtao Jiang Fucong Yu Hongyan school of Resource and information Technology China University of Petroleum Beijing 102249 China State Key Laboratory of Petroleum Resource and Prospecting China University of Petroleum Beijing 102249 China The No.7 Oil Production Factory Daqing Oilfield Company PetroChina Heilongjiang 163515 China

Low-resistivity oil layers are often missed in logging interpretation because of their resistivity close to or below the resistivity of nearby water layers. Typical low-resistivity oil layers have been found in the past few years in the Putaohua reservoir of the Puao Oilfield in the south of the Daqing placanticline by detailed exploration. Based on a study of micro-geological causes of low-resistivity oil layers, the macro-geological controlling factors were analyzed through comprehensive research of regional depositional background, geological structure, and oil-water relations combined with core, water testing, well logging, and scanning electron microscopy data. The results showed that the formation and distribution of Putaohua low-resistivity oil layers in the Puao Oilfield were controlled by depositional environment, sedimentary facies, diagenesis, motive power of hydrocarbon accumulation, and acidity and alkalinity of reservoir liquid. The low-resistivity oil layers caused by high bound-water saturation were controlled by deposition and diagenesis, those caused by high free-water saturation were controlled by structural amplitude and motive power of hydrocarbon accumulation. Those caused by formation water with high salinity were controlled by the ancient saline water depositional environment and faulted structure and those caused by additional conductivity of shale were controlled by paleoclimate and acidity and alkalinity of reservoir liquid. Consideration of both micro-geological causes and macro-geological controlling factors is important in identifying low-resistivity oil layers.

关键词： Daqing placanticline Puao Oilfield Putaohua oil layer low-resistivity oil layers microgeological causes macro-geological controlling factors

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EST-Based Identification of Genes Expressed in Skeletal Muscle of the Mandarin Fish (Siniperca chuatsi)

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Genomics,Proteomics & Bioinformatics 2011年第Z1期 30-36页

作者： Feng Ding1#, Wuying Chu2., Peng Cui1, Meng Tao2. Ruixue Zhou2. Falan Zhao2. Songnian Hu1*, and Jianshe Zhang2. 1CAS Key Laboratory of Genome sciences and information, Beijing Institute of Genomics, Chinese Academy of sciences, Beijing 10002., China 2.epartment of Bioengineering and Environmental science, Changsha university, Changsha 410003, China.

To enrich the genomic information of the commercially important fish species, we obtained 5,063 high-quality expressed sequence tags (ESTs) from the muscle cDNA database of the mandarin fish (Siniperca chuatsi). Clustering analysis yielded 1,62. unique sequences including 443 contigs (from 3,881 EST sequences) and 1,182.sin- gletons. BLASTX searches showed that 959 unique sequences shared homology to proteins in the NCBI non-redundant database. A total of 740 unique sequences were functionally annotated using Gene Ontology. The 1,62. unique sequences were assigned to Kyoto Encyclopedia of Genes and Genomes reference pathways, and the results indicated that transcripts participating in nucleotide metabolism and amino acid metabolism are relatively abundant in S. chuatsi. Meanwhile, we identified 15 genes to be abundantly expressed in muscle of the mandarin fish. These genes are involved in muscle structural formation and regulation of muscle differentiation and development. The most remarkable gene in S. chuatsi is nuclease diphosphate kinase B, which is represented by 449 EST sequences accounting for 8.86% of the total EST sequences. Our work provides a transcript profile expressed in the white muscle of the mandarin fish, laying down a foundation in better understanding of fish genomics.

关键词： mandarin fish cDNA library EST muscle

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The Influence of Preheat Temperature of Steel Plate on Steel-mushy Cu-graphite Bonding

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Journal of Wuhan university of Technology(Materials science) 2006年第3期21卷 12-14页

作者：张鹏 Department of Mechanical engineering Beijing Jiaotong UniversityBeijing 100044China

The pressing bonding of steel plate to QTi3.5-3.5 graphite slurry was conducted. Under the conditions of 530 ℃ for the preheat temperature of dies, 45% for the solid fraction of QTi3.5- 3.5 graphite slurry, 50 MPa for the pressure and 2.min for the pressing time, the relationship between the preheat temperature of steel plate and interfacial mechanical property of bonding plate was studied. The results show that when the preheat temperature of steel plate is lower titan 618 ℃ , the interfacial shear strength of bonding plate increases with the increasing of the preheat temperature of steel plate. When the preheat temperature of steel plate is higher than 618 ℃ , the interfacial shear strength decreases with the increasing of the preheat temperature of steel plate. When the preheat temperature of steel plate is 618 ℃ , the highest interfacial shear strength of bonding plate of 12..8 MPa can be got.

关键词： steel-mushy QTi3.5-3.5 graphite pressing bonding interfacial shear strength preheat temperature of steel plate

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Laboratory Investigation of Zinc Recovery fromEAF Dust by Bath Smelting Reduction

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International Journal of Minerals,Metallurgy and Materials 2000年第1期14卷 18-23页

作者： Weiqing Chen Tarek El Gammal Metallurgy school, university of {2. & Technology Beijing, Beijing 100083, China Institute for Ferrous Metallurgy, Aachen university of Technology, Germany Univ Sci & Technol Beijing Met Sch Beijing 100083 Peoples R China Aachen Univ Technol Inst Ferrous Met Aachen Germany

Bath smelting reduction for recovering zinc from EAF (Electric Arc Furnace) dust has been investigated in the laboratory. A degree of zinc volatilization of more than 99% was obtained from the process. Temperature has a clear influence on the reduction rate of ZnO in slag. The reduction rate of (ZnO) by [C] is the first order with respect to the content of ZnO in the slag. The apparent activation energy of the (ZnO) reduction reaction is 312.kJ/mol at 1300-1500℃.

关键词： EAF dust ZnO smelting reduction reduction rate

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Linear Quadratic Regulation for Linear Continuous-time Systems with Distributed Input Delay

Linear Quadratic Regulation for Linear Continuous-time Syste...

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第二十七届中国控制会议

作者： Liu Shuai1,Xie Lihua1,Zhang Huanshui2.1.school of EEE,Nanyang Technological university,Singapore 639798 {2. of Control science and engineering,Shandong university,Jinan 2.0061,P.R.China

This paper is concerned with the linear quadratic regulation（LQR） problem for linear continuous-time systems with distributed input *** this paper,we address the LQR problem by first establishing a duality between it and a smoothing problem for an associated stochastic backward system with output *** analytical solution to the LQR control is then derived by solving the smoothing problem and is given in terms of the solution of Riccati type partial differential equation of the same dimension as the plant（ignoring the delays） .The infinite horizon LQR problem is also considered in this paper and the convergence and stability analysis of the LQR controller is provided based on infinite dimensional system theory.

关键词： LQR Distributed delay Partial differential equation

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A template of rat brain based on fMRI T2. imaging

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Progress in Natural science:Materials International 2005年第6期15卷 502-506页

作者： HU Zhenghui1, WU Yigen2. WANG Xiaochuan3, WANG Jianzhi3, CHEN Feiyan1 and TANG Xiaowei1*(1. Department of Physics and Bio-X Laboratory, Zhejiang university, Hangzhou 31002., China 2. Institute of High Energy Physics and Key Laboratory of Nuclear Analysis Techniques, Chinese Academy of sciences,Beijing 100039, China 3. Department of Pathophysiology, Tongji Medical College, Huazhong university of science and Technology, Wuhan 430030, China) Department of Physics and Bio-X Laboratory Zhejiang University Hangzhou 310027 China Institute of High Energy Physics and Key Laboratory of Nuclear Analysis Techniques Chinese Academy of Sciences Beijing 100039 China Department of Pathophysiology Tongji Medical College Huazhong University of Science and Technology Wuhan 430030 China

The development of functional magnetic resonance imaging (fMRI) technology has made it possible to carry out functional brain imaging experiments in small animals. Usually, group data is required to form the assessment of population, which can not only increase the sensitivity of the overall experiment, but also allow the generalization of the conclusion to the whole population. In order to average the signals of functional brain images from different subjects, it is necessary to put all the mapping images into the same standard space (template image). However, up to now, most animal brain templates remain unavailable and it must be done by ourselves. In this study, a template image based on the brains of eight male Wistar rats is obtained, and it is successfully used in our present Alzheimer disease (AD)-like rat model studies as template for spatially normalizing images to the same stereotaxical space. The fMRI results processed with statistical parametric mapping (SPM99) software are in agreement with the results from immunohistochemical experiment, which proves that this method is universally applicable to the pathologic models of other small animals and to human brain lesion studies.

关键词： fMRI animal model atlas template normalization T*2.

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MECHANICAL MODELING OF THE BISTABLE BACTERIAL FLAGELLAR FILAMENT

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Acta Mechanica Solida Sinica 2011年第S1期24卷 1-16页

作者： Xiaoling Wang 1 Qingping Sun 2.1 ( 1 school of Mechanical engineering, {2. of science & Technology Beijing, Beijing 100083, China) ( 2.Department of Mechanical engineering, The Hong Kong {2. of science & Technology, Clear Water Bay, Kowloon, Hong Kong, China)

We extend the 2. Landau phase transition theory to the bacterial flagellar filament which displays the phase transition between the left handed normal form and the right handed semi-coiled form. The bacterial flagellar filament is treated as an elastic thin rod based on the Kirchhoff’s thin rod theory. Mechanical analysis is performed on the periodical phase transition of the filament between the two helical structures of the opposite charity. The curvature and twist are chosen as the order parameters in constructing the phase transition model of the filament. The established model is applied to study the instability properties of the filament and to investigate the loading and deformation conditions of the phase transition. In addition, the curvature and twist gradient energy are considered to describe the interface properties of the two phases.

关键词： bacterial flagellar filament Landau theory the Kirchhoff’s rod theory instability

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Inhibition of Inositol-1-phosphate Synthetase in Mycobacterium Tuberculosis by Chitosan-antisense Nanoparticles

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Journal of Wuhan university of Technology(Materials science) 2009年第1期24卷 87-90页

作者：李媛媛徐顺清 MOE Key Laboratory School of Public Health Tongji Medical College Huazhong University of Science and Technology

Oligodeoxynucleotides （ODNs） were combined with the biodegradable polymer chitosan to form chitosan-ODN nanoparticles by complex coacervation, in order to improve the sta-bility and intracellular penetration. The diameter of the nanoparticles was light strength size and ranged between 60 and 2.9 nm with a mean value of 132.nm, while zeta potential was between ＋12.and ＋2. mV at pH 5.5. The chitosan-ODN nanoparticles could partially protect the encapsulated ODN from nuclease degradation. Moreover, chitosan-ODN nanoparticles were much more effective in inhibiting the proliferation of *** than free ODN.

关键词： chitosan antisense oligodeoxynucleotides nanoparticle tuberculosis

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