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Multiparty quantum secret sharing of classical and quantum messages

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Progress in Natural science:Materials International 2007年第1期17卷 26-31页

作者： CHEN Pan, DENG Fuguo and LONG Guilu ( key laboratory for Quantum Information and Measurements, and Department of Physics, Tsinghua University, beijing 100084, china key laboratory of Beam technology and Material Modification, MOE, Institute of Low Energy Nuclear Physics, and Department of Material science and Engineering, beijing Normal University, beijing 100875, china beijing Radiation Center, beijing 100875, china key laboratory for Atomic and Molecular nano-sciences, Tsinghua University, beijing 100084, china) [a]key laboratory for Quantum Information and Measurements and Department of Physics Tsinghua University Beijing China [b]key laboratory of Beam technology and Material Modification MOE Institute of Low Energy Nuclear Physics and Department of Material Science and Engineering Beijing Normal University Beijing China [c]beijing Radiation Center Beijing China [d]key laboratory for Atomic and Molecular nano-sciences Tsinghua University Beijing China

A scheme for multiparty quantum secret sharing of classical and quantum messages is proposed by using entanglement swapping. This scheme can distribute not only the classical information but also the quantum informati... 详细信息

关键词： quantum secret sharing classical message quantum message EPR pair.

REACTION MECHANISM OF BENZOPHENONE-PHOTOINITIATED CROSSLINKING OF POLYETHYLENE

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Chinese Journal of Polymer science 2002年第4期20卷 291-307页

作者： Bao-jun Qu State key laboratory of Fire science and Department of Polymer science and Engineering University of science and technology of china Hefei 230026 china Univ Sci & Technol china State Key Lab Fire Sci Hefei 230026 Peoples R China Univ Sci & Technol china Dept Polymer Sci & Engn Hefei 230026 Peoples R China

The radical intermediates, the crosslink microstructures, and the reaction mechanism of benzophenone (BP)-photoinitiated crosslinking of low-density polyethylene (LDPE) and model compounds (MD) have been reviewed in detail. The spin-trapping electron spin resonance (ESR) spectra obtained from the LDPE/BP systems with spin-trap agents show that two kinds of polymer radical intermediates are mainly formed: tertiary carbon and secondary carbon radicals. The spin-trapping ESR studies of MD/BP systems give further evidence that photocrosslinking reactions of PE predominantly take place a sites of tertiary carbon, secondary carbon, and especially allylic carbon when available. The high resolution C-13-NMR spectra obtained from LDPE and MD systems show that the crosslink microstructures have H- and Y-type links and that their concentrations are of the same order. The fluorescence, ESR, C-13 and H-1-NMR spectra from the PE and MD systems demonstrate that the main photoreduction product of BP (PPB) is benzpinacol formed by the recombination of two diphenylhydroxymethyl (K-.) radical intermediates. Two new PPB products: an isomer of benzpinacol with quinoid structure, 1-phenylhydroxymethylene-4-diphenylhydroxymethyl-2,5-cyclobexadiene and three kinds of alpha-alkyl-benzhydrols have been detected and identified. These results provide new experimental evidence for elucidating the reaction mechanism in the BP-photoinitiated crosslinking of polyethylene.

关键词： photocrosslinking mechanism polymer radical intermediates crosslink microstructures photolytic products of benzophenone polyethylene model compound

Prediction of Enthalpies of Fusion for Divalent Rare Earth Halides Based on Modeling by Artificial Neural Networks and Pattern Recognition

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International Journal of Minerals,Metallurgy and Materials 1999年第1期13卷 24-26页

作者： Yimin Sun Zhiyu Qiao Minghong He(Applied science School, University of science & technology beijing, beijing 100083, china)(national Natural science Foundation of china, beijing 100083, china) Applied science School University of Science and Technology Beijing Beijing 100083 China national Natural science Foundation of china Beijing 100083 China

The artificial neural network (ANN) and the pattern recognition were applied to study the correlation of enthalpies of fusion for divalent rare earth halides with their microstructural parameters,such as ionic radius and electronegativity. The model,represented by a back-propagation netal network, was trained with a 12 set of published data for divalent rare earth halides and then was used to predict the unknown ones. Also the criterion equations were ptesented to determine the enthalpies of fuSion for divalent rare earth halides using pattern recognition in mis work. The results from the model in ANN and criterion equations are in very good agreement with reference data.

关键词： BP neural network pattern recognition enthalpy of fusion divalent rare earth halides microstructural parameters

Multiparty simultaneous quantum identity authentication with secret sharing

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science china(Physics,Mechanics & Astronomy) 2008年第3期51卷 321-327页

作者： YANG YuGuang1,2,WEN QiaoYan3 & ZHANG Xing4,5 1 College of Computer science and technology,beijing University of technology,beijing 100022,china 2 State key laboratory of Information Security (Graduate University of the Chinese Academy of sciences),beijing 100049,china 3 School of science,beijing University of Posts and Telecommunications,beijing 100876,china 4 Institute of Electronic technology,Information Engineering University,Zhengzhou 450004,china 5 Trusted Computing laboratory,beijing University of technology,beijing 100022,china College of Computer science technology Beijing University of Technology Beijing 100022 China State key laboratory of Information Security [Graduate University of the Chinese Academy of sciences] Beijing 100049 China School of science Beijing University of Posts Telecommunications Beijing 100876 China Institute of Electronic technology Information Engineering University Zhengzhou 450004 China Trusted Computing laboratory Beijing University of Technology Beijing 100022 China

Two multiparty simultaneous quantum identity authentication (MSQIA) protocols based on secret sharing are presented. All the users can be authenticated by a trusted third party (TTP) simultaneously. In the first protocol,the TTP shares a random key K with all the users using quantum secret sharing. The ith share acts as the authentication key of the ith user. When it is necessary to perform MSQIA,the TTP generates a random number R secretly and sends a sequence of single photons encoded with K and R to all the users. According to his share,each user performs the corresponding unitary operations on the single photon sequence sequentially. At last,the TTP can judge whether the impersonator exists. The sec-ond protocol is a modified version with a circular structure. The two protocols can be efficiently used for MSQIA in a network. They are feasible with current technol-ogy.

关键词： quantum identity authentication secret sharing quantum cryptography

Fuzzy dynamic characteristic model based attitude control of hypersonic vehicle in gliding phase

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science china(Information sciences) 2011年第3期54卷 448-459页

作者： LUO Xiong 1,2 & LI Jiang 1 1 Department of Computer science and technology, key laboratory of Advanced Control of Iron and Steel Process (Ministry of Education), University of science and technology beijing, beijing 100083, china 2 national laboratory of Space Intelligent Control, beijing 100190, china 1. Department of Computer science and technology Key Laboratory of Advanced Control of Iron and Steel Process (Ministry of Education) University of Science and Technology Beijing Beijing 100083 China2. National Laboratory of Space Intelligent Control Beijing 100190 China

The intelligent autonomous control of hypersonic vehicles has aroused great interest from the field of spacecraft. To solve the problem of longitudinal attitude control of hypersonic vehicle in gliding phase, a new intelligent controller is proposed in this paper. This new controller is based on the fuzzy dynamic characteristic modeling method. The fuzzy logic is introduced into the characteristic modeling by dividing the whole restriction range into several subspaces. Simulations show that this modification greatly improves the performance of the original method. With the same whole restriction range the fuzzy dynamic characteristic modeling decreases the time of convergence, and at the same time makes the attitude angle tracing more precise and robust. Since the sub-model is a characteristic model that has stronger adaptiveness than a fixed local model, the number of fuzzy rules is greatly reduced. Our model sharply reduces the complexity in constructing a fuzzy dynamic model. Finally, simulation results are given to show the effectiveness of the proposed approach in dealing with the attitude control problem of hypersonic vehicle in gliding phase.

关键词： hypersonic vehicle gliding attitude control fuzzy dynamic characteristic modeling

Relationship between Ballistic Coefficient and Static Mechanical Properties for Armor Materials

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Journal of University of science and technology beijing 2001年第1期8卷 53-54页

作者： Junpin Lin, Yong Zhang, Zhi Lin, Guoliang Chen The State key laboratory for Advanced Metal Materials, University of science and technology beijing, beijing 100083, china Univ Sci & Technol beijing State Key Lab Adv Met Mat Beijing 100083 Peoples R China

The relationship between the ballistic coefficient and the static mechanical properties of armor materials was studied. The results show that the ballistic coefficient is determined by the strength, hardness and the toughness of materials. According to the Martel rule, the equation of the relationship between ballistic coefficient and static mechanical properties satisfies the following formula: W-s=M(1+NK1C/rho )Hr. From the mixture law of composite, the prerequisite, for which ballistic coefficient has maximum to reinforcement volume fraction, is obtained by the following equation: dWs/Df=b(K(1)rho (0)-K(0)rho (1))H/rho (2)+(a+bK/rho)(H-1-H-0).

关键词： armor materials ballistic coefficient toughness

Experimental measurement of growth patterns on fossil corals:Secular variation in ancient Earth-Sun distances

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Chinese science Bulletin 2010年第35期55卷 4010-4017页

作者： ZHANG WeiJia1,3,4,LI ZhengBin2,3 & LEI Yang1 1 Department of Physics,Peking University,beijing 100871,china 2 Department of Electrical Engineering and Computer science,Peking University,beijing 100871,china 3 State key laboratory of Advanced Optical Communication Systems & Networks,Peking University,beijing 100871,china 4 Committee of Yuanpei Honors Program,Peking University,beijing 100871,china Department of Physics Peking University Beijing 100871 China State key laboratory of Advanced Optical Communication Systems & Networks Peking University Beijing 100871 China Committee of Yuanpei Honors Program Peking University Beijing 100871 China Department of Electrical Engineering and Computer science Peking University Beijing 100871 China

In recent years,much attention has been given to the increase in the Earth-Sun distance,with the modern rate reported as 5-15 m/cy on the basis of astronomical ***,traditional methods cannot measure the ancient leaving rates,so a myriad of research attempting to provide explanations were met with unmatched *** this paper we consider that the growth patterns on fossils could reflect the ancient Earth-Sun *** mechanical analysis of both the Earth-Sun and Earth-Moon systems,these patterns confirmed an increase in the Earth-Sun *** a large number of well-preserved specimens and new technology available,both the modern and ancient leaving rates could be measured with high precision,and it was found that the Earth has been leaving the Sun over the past 0.53 billion *** Earth's semi-major axis was 146 million kilometers at the beginning of the Phanerozoic Eon,equating to 97.6% of its current *** modern leaving rates are 5-14 m/cy,whereas the ancient rates were much *** results indicate a special expansion with an average expansion coefficient of 0.57H0 and deceleration in the form of Hubble *** the basis of experimental results,the Earth's semi-major axis could be represented by a simple formula that matches fossil measurements.

关键词：地球太阳古代距离生长模式实验石珊瑚量化

Precipitation of α Phase in the Massive and Feathery Structures in TiAl Alloys during Aging in the Single α Field

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Journal of Materials science & technology 1999年第5期15卷 469-472页

作者： Weijun ZHANG and Glloliang CHEN(State key laboratory for Advanced Metals and Materials, University of science and technology beijing, beijing 100083, china To whom correspondence should be addressed ) Univ Sci & Technol beijing State Key Lab Adv Met & Mat Beijing 100083 Peoples R China

Precipitation of α-phase in massive and feathery microstructures was studied during aging in the single α field. It was found that the α-phase mainly precipitated along the γ-plate interfaces as laths in the feathery structure, while it nucleated at various sites in the massive structure in the form of particles and dominantly as plates. Precipitation of α-plates in the massive structure occurred by the difFusional ledge mechanism. The γm→α reaction proceeded by the growth of previously nucleated α-precipitates, and chiefly by the development of new α-plates

关键词： TiAl Precipitation of Field Phase in the Massive and Feathery Structures in TiAl Alloys during Aging in the Single

Influence of magnetic current on the ground state entanglement in an isotropic transverse XY chain

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Progress in Natural science:Materials International 2007年第10期17卷 1147-1151页

作者： Liu Dan1,2 , Zhang Yong3 and Long Guilu1,2(1. key laboratory for Atomic and Molecular nanosciences, and Department of Physics, Tsinghua University, beijing 100084, china 2. Center of Quantum Information science and technology, Tsinghua national laboratory for information science and technology, beijing 100084, china 3. Institute of Physics, School of sciences, beijing University of Posts and Telecommunications, beijing 100876, china) key laboratory for Atomic and Molecular nanosciences and Department of Physics Tsinghua University Beijing 100084 China Center of Quantum Information science and technology Tsinghua National Laboratory for information Science and Technology Beijing 100084 China Institute of Physics School of Sciences Beijing University of Posts and Telecommunications Beijing 100876 China

We study the ground state entanglement in a three-qubit XY chain under the influence of a magnetization current. It is found that the ground state changes from a W state to a disentangled state as the magnetic field varies. When the Lagrange multiplier λ>3, namely under a strong magnetic current, the ground state holds onto a W state for a large range of the magnetic field strength. A phase transition to the magnetization-current phase occurs under a certain condition.

关键词： Heisenberg-XY chain magnetic-current phase transition.