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Quantum threshold group signature

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Science china(Physics,Mechanics & Astronomy) 2008年第10期51卷 1505-1514页

作者： YANG YuGuang1,2,3 & WEN QiaoYan4 1 College of Computer Science and Technology, beijing University of Technology, beijing 100124, china 2 State Key laboratory of Integrated Services Network, Xidian University, Xi’an 710071, china 3 State Key laboratory of Information Security (Graduate University of Chinese Academy of Sciences), beijing 100049, china 4 State Key laboratory of Networking and Switching Technology, beijing University of Posts and Tele-communications, beijing 100876, china College of Computer Science and Technology Beijing University of Technology Beijing 100124 China State Key laboratory of Integrated Services Network Xidian University Xi’an 710071 China State Key laboratory of Information Security Graduate University of Chinese Academy of Sciences Beijing 100049 China State Key laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China

In most situations, the signer is generally a single person. However, when the message is written on behalf of an organization, a valid message may require the approval or consent of several persons. Threshold signature is a solution to this problem. Generally speaking, as an authority which can be trusted by all members does not exist, a threshold signature scheme without a trusted party appears more attractive. Following some ideas of the classical Shamir’s threshold signature scheme, a quantum threshold group signature one is proposed. In the proposed scheme, only t or more of n persons in the group can generate the group signature and any t-1 or fewer ones cannot do that. In the verification phase, any t or more of n signature receivers can verify the message and any t-1 or fewer receivers cannot verify the validity of the signature.

关键词： threshold quantum signature trusted party quantum cryptography

A new approach of cascade utilization of the chemical energy of fuel

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Progress in Natural Science:Materials International 2006年第5期16卷 518-523页

作者： HAN Wei, JIN Hongguang and LIN Rumou ( Institute of Engineering Thermophysics, Chinese Academy of Sciences, beijing 100080, china Graduate School of the Chinese Academy of Sciences, beijing 100080, china) [a]Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing China [b]Graduate School of the Chinese Academy of Sciences Beijing China

The indirect release of chemical energy of fuel is investigated, and a new mechanism is proposed to identify the cascade utilization of chemical energy of fuel more clearly. Based on the concept of energy level, the internal phenomenon of the indirect chemical energy release is disclosed, and the equations of energy level describing the utilization of chemical energy and thermal energy during the indirect chemical energy release process are obtained. From theoretical analysis, we find that the superiority of the indirect chemical energy release of fuel comes from the cascade utilization of the fuel's chemical energy. Moreover, the cascade utilization of chemical energy is verified by the investigation of CRGT (chemically recuperated gas turbine). As a result, the thermal exergy obtained from the chemical energy release of fuel increases by 2 % -3 % . The results obtained here may help a deeper understanding of indirect chemical energy release of fuel and provide a theoretical basis for the synthesis of innovative energy systems.

关键词： chemically recuperated gas turbine methane/steam reforming chemical energy level cascade utilization.

Two mode photon bunching effect as witness of quantum criticality in circuit QED

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Science china(Physics,Mechanics & Astronomy) 2009年第12期52卷 1898-1905页

作者： AI Qing1,WANG YingDan2,LONG GuiLu1,3 & SUN ChangPu4 1 Department of Physics,Tsinghua University,beijing 100084,china 2 Department of Physics,University of Basel,Klingelbergstrasse 82,4056 Basel,Switzerland 3 Tsinghua National laboratory for Information Science and Technology,beijing 100084,china 4 Institute of Theoretical Physics,Chinese Academy of Sciences,beijing 100080,china 1. Department of Physics Tsinghua University Beijing 100084 China 2. Department of Physics University of Basel Klingelbergstrasse 82 4056 Basel Switzerland 3. Tsinghua National laboratory for Information Science and Technology Beijing 100084 China 4. Institute of Theoretical Physics Chinese Academy of Sciences Beijing 100080 China

We suggest a scheme to probe critical phenomena at a quantum phase transition (QPT) using the quantum correlation of two photonic modes simultaneously coupled to a critical system. As an experimentally accessible physical implementation,a circuit QED system is formed by a capacitively coupled Josephson junction qubit array interacting with one superconducting transmission line resonator (TLR). It realizes an Ising chain in the transverse field (ICTF) which interacts with the two magnetic modes propagating in the TLR. We demonstrate that in the vicinity of criticality the originally independent fields tend to display photon bunching effects due to their interaction with the ICTF. Thus,the occurrence of the QPT is reflected by the quantum characteristics of the photonic fields.

关键词： quantum phase transition photon bunching circuit QED

Threshold proxy quantum signature scheme with threshold shared verification

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Science china(Physics,Mechanics & Astronomy) 2008年第8期51卷 1079-1088页

作者： YANG YuGuang1,3,4 & WEN QiaoYan2 1 College of Computer Science and Technology,beijing University of Technology,beijing 100124,china 2 State Key laboratory of Networking and Switching Technology,beijing University of Posts and Tele-communications,beijing 100876,china 3 State Key laboratory of Integrated Services Network,Xidian University,Xi’an 710071,china 4 State Key laboratory of Information Security(Graduate University of Chinese Academy of Sciences) ,beijing 100049,china 1. College of Computer Science and Technology Beijing University of Technology Beijing 100124 China 3. State Key laboratory of Integrated Services Network Xidian University Xi’an 710071 China 4. State Key laboratory of Information Security (Graduate University of Chinese Academy of Sciences) Beijing 100049 China 2. State Key laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China

A threshold proxy quantum signature scheme with threshold shared verification is proposed. An original signer could authorize a group as its proxy signers. Then only t or more of n persons in the proxy group can generate the proxy signature on behalf of the original signer and any t-1 or fewer ones cannot do that. When the proxy signature needs to be verified,any t or more of n persons belonging to the verification group can verify the message and any t-1 or fewer ones cannot verify the validity of the proxy signature.

关键词： quantum signature threshold proxy quantum group signature threshold shared verification

Fluorescence dynamics of interactions between polyamide PyPyPyβDp and DNA

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Science china Chemistry 2006年第1期49卷 75-80页

作者： ZHANG Huijuan1,2, WANG Jin3, WU Yishi1, YUAN Gu3, AI Xicheng1, WANG Li4 & ZHANG Jianping1 1. State Key laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, beijing 100080, china 2. School of Life Science and Technology, beijing Institute of Technology, beijing 100081, china 3. College of Chemistry and Molecular Engineering, Peking University, beijing 100080, china 4. Center for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, beijing 100080, china Correspondence should be addressed to Ai Xicheng and Zhang Jianping 1. State Key laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China 2. School of Life Science and Technology Beijing Institute of Technology Beijing 100081 China 3. College of Chemistry and Molecular Engineering Peking University Beijing 100080 China 4. Center for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China

The photophysical properties of the polyamide PyPyPyβDp (PPP) were investigated by means of steady-state absorption and fluorescence spectroscopies, as well as time-resolved fluo-rescence spectroscopy. It was found that the excited-state properties of PPP are very sensitive to solvents. In TKMC buffer PPP exhibited weak fluorescence with a decay time constant of 16 ps, while with the decrease of the solvent polarity PPP showed the blue-shifted peak position, increased inten-sity and lengthened life-time for its fluorescence behavior. In the presence of calf thymus DNA, it was observed that the fluorescence intensity was enhanced and the fluorescence lifetime increased from 16 to 32 ps for PPP, which verified that PPP bound into the minor groove of DNA duplex.

关键词： polyamide (PPP), calf thymus DNA (ctDNA), time-resolved fluorescence spectroscopy, recognition dynamics.

Threshold quantum secret sharing between multi-party and multi-party

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Science china(Physics,Mechanics & Astronomy) 2008年第9期51卷 1308-1315页

作者： YANG YuGuang1,2,3 & WEN QiaoYan4 1 College of Computer Science and Technology,beijing University of Technology,beijing 100124,china 2 State Key laboratory of Integrated Services Network,Xidian University,Xi’an 710071,china 3 State Key laboratory of Information Security (Graduate University of Chinese Academy of Sciences),beijing 100049,china 4 State Key laboratory of Networking and Switching Technology,beijing University of Posts and Tele-communications,beijing 100876,china College of Computer Science and Technology Beijing University of Technology Beijing 100124 China State Key laboratory of Integrated Services Network Xidian University Xi’an 710071 China State Key laboratory of Information Security (Graduate University of Chinese Academy of Sciences) Beijing 100049 China State Key laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China

A threshold quantum secret sharing (TQSS) scheme between multi-party and multi-party was proposed using a sequence of single photons,which is useful and efficient when the parties of communication are not all present. We described the process of this TQSS scheme and discussed its security. It was shown that entan-glement is not necessary for quantum secret sharing. Moreover,the theoretic effi-ciency was improved to approach 100% as almost all the instances can be used for generating the private key,and each photon can carry one bit of information. This protocol is feasible with the present-day technique.

关键词： threshold quantum secret sharing quantum cryptography single photon multi-party and multi-party

SOLID PHASE TRANSITION OF SYNDIOTACTIC POLYSTYRENE IN SUPERCRITICAL CO_2

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Chinese Journal of Polymer Science 2002年第3期20卷 191-196页

作者： Yu-ying Li Jia-song He State Key laboratory of Engineering Plastics, Center for Molecular Science, Institute of Chemistry Chinese Academy of Sciences, beijing 100080 china Chinese Acad Sci Inst Chem Ctr Mol Sci State Key Lab Engn Plast Beijing 100080 Peoples R China

Solid phase transition of the a form crystals to the 3 form crystals in syndiotactic polystyrene (sPS) samples has occurred in supercritical CO2. This transformation is different from those detected under other conditions. The effects of some factors (e.g. time, temperature, and pressure) on the solid phase transformation of sPS in supercritical CO2 were analyzed in detail. Experimental results show that longer time, higher temperature or higher pressure favors the transformation of the a form crystals to the beta form crystals.

关键词： solid phase transition syndiotactic polystyrene supercritical CO2

MODIFICATION OF EPOXY RESIN WITH POLYSILOXANE BEARING PENDANT QUATERNARY AMMONIUM GROUPS

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Chinese Journal of Polymer Science 2002年第6期20卷 537-541页

作者： Zuo-xin Huang Ying Huang Yun-zhao Yu The State Key laboratory of Engineering Plastics, Institute of Chemistry Chinese Academy of Sciences, beijing 100080 china Chinese Acad Sci Inst Chem State Key Lab Engn Plast Beijing 100080 Peoples R China

Polysiloxane bearing pendant quaternary ammonium groups (PSI) was used to modify the surface properties of epoxy resins. In the cured resin, PSI formed the dispersed phase. Remarkable enrichment and gradient distribution of polysiloxane on the surface region of the epoxy resins were demonstrated by XPS analysis. The composition and properties of the surface of PSI-modified epoxy resin, which is in contact with the mold, are dependent on the material of the mold. Through the incorporation. of PSI, epoxy resins with low surface energy and low friction coefficient were obtained. Polysiloxane with lower ionic group content shows a higher degree of enrichment on the resin surface and leads to a higher contact angle against water, while the polysiloxane having optimum compatibility with the epoxy resin shows a greater effect in reducing the static friction coefficient of the resin against glass.

关键词： polysiloxane epoxy resin surface composition friction coefficient

Two-parameter-dependent Drag Coefficient Over Sea Surface by Turbulent Modeling

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Communications in Nonlinear Science and Numerical Simulation 1999年第1期4卷 8-12页

作者： Jiachun LI and Zifan ZHANG (Institute of mechanics, CAS, beijing 100080, china) Institute of mechanics CAS Beijing 100080 China

A new model accounting for both turbulence and sea state effects has been proposed in the current paper to describe momentum exchange through air-sea interface. While long wave components mainly change air flow profile, short wave components exert their influences on the momentum exchange via turbulent stress, which leads to the growth of drag coefficients by a factor of two in young wave age circumstances. As a typical case study, we have considered neutral ABL over a representative regular wave with roughness due to short capillary waves riding over it. The results by the present model are in reasonable agreement with Maat’s analysis numerically fitted by HEXMAX data and Janssen’s results. Two parameter dependence of drag coefficient can resolve the existing discrepency between theory and observations.

关键词： air-sea interaction drag coefficient waveage