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reconfigurable design and implementation of the MD6 Hash function

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The Journal of china Universities of posts and Telecommunications 2010年第2期17卷 109-115页

作者： GAO Xian-wei Dep.r.ment of electronic and Information Engineering,beijing electronic science and technology institute,beijing 100070,china Dep.r.ment of electronic and Information Engineering Beijing Electronic Science and Technology Institute Beijing 100070 China

Efficient reconfigurable field programmable gate array （FpGA） architectures for the MD6-224/256/384/512 Hash algorithm are proposed in this article. The basic iterative compact design requires 923 ALMs and achieves a throughput ranging from 225 Mbit/s to 394 Mbit/s at a maximum frequency of 198 MHz. The 32-step-urtrolled high-throughput design requires 7 090 ALMs and achieves a throughput ranges from 5 776 Mbit/s to 9 490 Mbit/s at a maximum frequency of 173 MHz. The simulation results show that high flexibility and efficient FpGA implementation of the MD6 Hash function is achieved.

关键词： SHA-3 MD6 reconfigurable iterative loop-unrolling

Synchronization of Digital Chaos in Secure Communication Systems

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Journal of University of science and technology beijing 2001年第4期8卷 299-305页

作者： Geng Zhao, Deling Zheng, ShaojunHuang 1)College of Electric science and technology beijing. beijing 100070, china 2)Information Engineering School, University of science and technology beijing. beijing 100083, china College of Electric science and technology beijing Beijing 100070 China Information Engineering School University of Science and Technology Beijing Beijing 100083 China

The theories of synchronization based on secure communications using digital chaos are presented. A new synchronous method-cycles-interval pulse drive is developed and realized. Exp.r.mental results show it is available, and in order to reduce synchronous noise, a method using model references solves the ratio of signal power to noise power, so the secure communication system can be realized.

关键词： digital chaotic synchronization cycles-interval pulses drive synchronous noise model reference

Chaotic attitude and reorientation maneuver for completely liquid-filled spacecraft with flexible appendage

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Acta Mechanica Sinica 2009年第2期25卷 271-277页

作者： B. Yue Dep.r.ment of Mechanics, School of science,beijing institute of technology, 100081 beijing, china Dep.r.ment of Mechanics School of Science Beijing Institute of Technology Beijing China

The present pap.r.investigates the chaotic attitude dynamics and reorientation maneuver for completely viscous liquid-filled spacecraft with flexible appendage. All of the equations of motion are derived by using Lagrangian mechanics and then transformed into a form consisting of an unp.r.urbed p.r. plus p.r.urbed terms so that the system＇s nonlinear characteristics can be exploited in phase space. Emphases are laid on the chaotic attitude dynamics produced from certain sets of physical p.r.meter values of the spacecraft when energy dissipation acts to derive the body from minor to major axis spin. Numerical solutions of these equations show that the attitude dynamics of liquid-filled flexible spacecraft possesses characteristics common to random, non- p.r.odic solutions and chaos, and it is demonstrated that the desired reorientation maneuver is guaranteed by using a pair of thruster impulses. The control strategy for reorientation maneuver is designed and the numerical simulation results are presented for both the uncontrolled and controlled spins transition.

关键词： Nonlinear attitude dynamics Attitude reorientation maneuver Control strategyLiquid-filled spacecraft

Flotation Sep.r.ting rutile from Calcium and Silicon Gangue Minerals

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rare Metals 2001年第4期20卷 205-208页

作者： Hao Ding1, HaiLin 2 1) beijing Academy of Building Materials, beijing 100041, china 2) University of science and technology beijing, beijing 100083, china 北京建筑材料研究院北京 100041 北京科技大学北京 100083

rutile sep.r.tion from calcite, apatite and quartz by flotation was investigated. The results show that the rutile sep.r.tion from calcium and silicon gangue minerals can be realized with alkyl-imino-bismethylene phos... 详细信息

关键词： rutile calcium and silicon gangue minerals flotation sep.r.te alkyl-imino-bismethylene phosphoric acid sodium hexametaphosphate

Density functional theory study of the reaction paths of reactions of CH3C（O）O2 radicals with HO2 in the gas phase

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progress in Natural science:Materials International 2006年第12期16卷 1269-1274页

作者： ZHOU Yuzhi~ 1,2 , ZHANG Shaowen~1 and LI Qianshu~1**(1. State Key Laboratory of Explosion science and technology, beijing institute of technology, beijing 100081, china 2. beijing institute of Education, beijing 100044, china) State Key Laboratory of Explosion science and technology Beijing Institute of Technology Beijing 100081 China beijing institute of Education Beijing 100044 China

A DFT study on the reactions between CH_3C（O）O_2and HO_2radicals has been carried out. It is suggested that both the triplet and singlet potential surfaces involve a complex mechanism with the formation of loosely bound intermediate complexes of reactants and products. The reaction prefers to occur on the triplet surface to produce p.r.cetic acid (CH_3C（O）O_2H) and triplet O_2molecule. The CH_3C（O）O_2H can further convert into CH_3C（O）O and HO radicals.

关键词： acetyl p.r.xy radicals HO2 radicals reaction mechanism DFT.

Fabrication of Biomimetic Water Strider Legs Covered with Setae

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Journal of Bionic Engineering 2009年第1期6卷 1-6页

作者： Zhi-guo Zhou, Zhi-wen LiuDep.r.ment of electronic Engineering, beijing institute of technology, beijing 100081, p. r. china Dep.r.ment of electronic Engineering Beijing Institute of Technology Beijing P. R. China

Water striders have remarkable water-repellent legs that enable them to stand effortlessly and move quickly on *** physics indicates this feature is due to a surface-tension effect caused by the special hierarchical structure of the legs,which are covered with a large number of inclined setae with fine nanogrooves inducing water *** insp.r.s us to fabricate special water-repellent structure on functional surfaces through the coop.r.tion between the surface treatment and the surface micro-and nanostructures,which may bring great advantages in a wide variety of *** this pap.r.we present a procedure for fabricating biomimetic water strider legs covered with setae using polycarbonate Track-Etched(pCTE)membranes as *** choosing ap.r.priate membrane lengths,diameters,pitches and densities of the setae,the biomimetic legs can be fabricated conveniently and at a low *** we investigated the relationship between stiffness of the molding materials,high aspect ratio and density,which affect the fidelity of fabrication and self adhesion,to optimize the stability of *** knowledge we gained from this study will offer imp.r.ant insights into the biomimetic design and fabrication of water strider setae.

关键词： water strider biomimetic setae pCTE membrane polydimethylsiloxane (pDMS) nanop.r.icle adhesion

raman Scattering and t-phase Lattice Vibration of 3% (mole fraction) Y_2O_3-ZrO_2

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Journal of Materials science & technology 2004年第5期20卷 485-489页

作者： Xinglun TANG and Xinhua ZHENGSchool of Materials science and Engineering, beijing institute of technology, beijing 100081, china Sch. of Mat. Sci. and Eng. Beijing Inst. of Technol. Beijing 100081 China

The raman spectra of 3% (mole fraction) Y2O3-ZrO2 (3Y) are obtained at different temp.r.ture from 77 K to 853 K. The results show that 260 cm-1 Eg and 460 cm-1 Eg modes on the spectra shift toward lower wave number with the increase of temp.r.ture; meanwhile, the continuity of the Half Width at Half Maximum (HWHM) and wave number (frequency) of raman bands are broken and t-phase only p.r.ially transforms to m-phase at 523 K. Based on the exp.r.mental results, this pap.r.discusses the t-phase lattice vibration of 3Y and presents the images of vibration displacement of six raman-active modes for t-phase of ZrO2. The analysis indicates that there are diversities existing in the displacement of the atomic vibration of raman-active modes because of their different symmetries at various temp.r.ture, which leads to the different change tendencies of raman bands. Furthermore, the abrupt changes of some raman-active modes indicating the atomic displacement are assumed to be the condensations of phonon modes in the t→m phase transition.

关键词： raman scattering Zirconia phase transition Condensation of phonon

The effects of relative density of metal foams on the stresses and deformation of beam under bending

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Acta Mechanica Sinica 2007年第4期23卷 409-414页

作者： Aiyu Zhu Tianyou Fan Dep.r.ment of Mathematics,School of science,beijing institute of technology,p.O.Box 327,beijing 100081,china Dep.r.ment of physics,School of science,beijing institute of technology,p.O.Box 327,beijing 100081,china Dep.r.ment of Mathematics School of Science Beijing Institute of Technology Beijing China Dep.r.ment of physics School of Science Beijing Institute of Technology Beijing China

The exact analytic solution of the p.r. bending beam of metallic foams is given. The effects of relative density of the material on stresses and deformation are revealed with the Triantafillou and Gibson constitutive law （TG model） taken as the analysis basis. Several examples for individual foams are discussed, showing the imp.r.ance of compressibility of the cellular materials. One of the objects of this study is to generalize Hill＇s solution for incompressible plasticity to the case of compressible plasticity, and a kinematics p.r.meter is brought into the analysis so that the velocity field can be determined.

关键词： Metal foams - relative density Compressible plasticity Constitutive law - TG model

Theoretical observation of hexaatomic molecules containing pentacoordinate planar carbon

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science china Chemistry 2008年第11期51卷 1030-1035页

作者： LUO Qiong State Key Laboratory of Explosion science and technology, beijing institute of technology, beijing 100081, china State Key Laboratory of Explosion science and technology Beijing Institute of Technology Beijing China

The smallest molecules up to date containing a D5h pentacoordinate planar carbon (ppC) atom, CBe5 and CBe54-, are presented by means of ab initio calculations. To gain a better understanding about which electronic factors contribute to their stabilization, natural bond orbital (NBO) analysis and the nucleus independent chemical shifts (NICS) were calculated. The data rep.r.ed here suggest that D5h CBe5 is σ aromaticity in nature, while in D5h CBe54- π aromaticity is dominating. The classical octet rule is well satisfied in both molecules, and is one of the fundamental reasons to understand the stability of the pentagon structures. The Be5 ring serves as σ donor in D5h CBe5, and π-acceptor in D5h CBe54-. The D5h CBe54- possessing 18 valence electrons with a closed-shell electron configuration is the most plau-sible candidate for exp.r.mental detection.

关键词： pentacoordinate planar carbon Be5 ring ab initio