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Improvement of water resistance of long afterglow SrAl_2._4: Dy, Eu phosphor by coating with SiO_2.film

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Rare Metals 2002年第2期21卷 152-155页

作者： ZHANG Junying, CHEN Qingming, LIN Yuanhua, and ZHANG Zhongtaistate key {2. of New Ceramics and Fine Processing, Department of Materials Science and {2., tsinghua university,beijing 100084, China Department of Materials Science and engineering Tsinghua University State Key Laboratory of New Ceramics and Fine Processing 北京 100084

The long afterglow SrAl_2._4: Dy, Eu phosphor is liable tohydrolyze in water with deterioration of the lumin- escent ***_2._4: Dy, Eu phosphors were therefore heated at 60-90 deg. C inTEOS sol to form a surface gel and then heat-treated at 400 deg. C toobtain SiO_2.coated phosphors. Observation by ?Transmission ElectronMicroscope (TE) and X- ray photoelectron spectroscopy (XPS) showsthat a thin silica film forms on the surface of the phosphors. Thecoating procedure can be illustrated by a four-step process and thetransparent silica film can suppress the hydrolysis process, so thatthe luminescent properties of the phosphors are unimpaired or evenbetter.

关键词： phosphors coating luminescent materials SrAl_2._4

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 10012., 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 {2. of Integrated Services Network Xidian University Xi’an 710071 China state key {2. of Information Security Graduate University of Chinese Academy of Sciences Beijing 100049 China state key {2. 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

The refined theory of transversely isotropic piezoelectric rectangular beams

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Science China(Physics,Mechanics & Astronomy) 2006年第4期49卷 473-486页

作者： GAO Yang1 & WANG Minzhong2.1. College of Science, China Agricultural university, beijing 100083, China 2. {2. key laboratory for Turbulence and Complex Systems and Department of Mechanics and Engi- neering Science, Peking university, beijing 100871, China 1. College of Science China Agricultural University Beijing 100083 China 2. state key {2. for Turbulence and Complex Systems and Department of Mechanics and {2. Science Peking University Beijing 100871 China

The problem of deducing one-dimensional theory from two-dimensional theory for a transversely isotropic piezoelectric rectangular beam is investigated. Based on the piezoelasticity theory, the refined theory of piezoelectric beams is derived by using the general solution of transversely isotropic piezoelasticity and Lur'e method without ad hoc assumptions. Based on the refined theory of piezoelectric beams, the exact equations for the beams without transverse surface loadings are derived, which consist of two governing differential equations: the fourth-order equation and the transcendental equation. The approximate equations for the beams under transverse loadings are derived directly from the refined beam theory. As a special case, the governing differential equations for transversely isotropic elastic beams are obtained from the corresponding equations of piezoelectric beams. To illustrate the application of the beam theory developed, a uniformly loaded and simply supported piezoelectric beam is examined.

关键词： rectangular beams, the refined theory, piezoelectric, transversely isotropic.

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 10012.,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 {2. of Integrated Services Network Xidian University Xi’an 710071 China state key {2. of Information Security (Graduate {2. of Chinese Academy of Sciences) Beijing 100049 China state key {2. 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

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 10012.,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 {2. of Integrated Services Network Xidian University Xi’an 710071 China 4. state key {2. of Information Security (Graduate {2. of Chinese Academy of Sciences) Beijing 100049 China 2. state key {2. 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

Intermediate processes and critical phenomena: Theory, method and progress of fractional operators and their applications to modern mechanics

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Science China(Physics,Mechanics & Astronomy) 2006年第3期49卷 257-272页

作者： XU Mingyu1 & TAN Wenchang2.1. Institute of Applied Mathematics, School of Math & System Science, Shandong university, Jinan 2.0100, China 2. state {2. {2. of Turbulence and Complex Systems & Department of Mechanics and engineering Science, Peking university, beijing 100871, China 1. Institute of Applied Mathematics School of Math & System Science Shandong University Jinan 250100 China 2. state key {2. of Turbulence and Complex Systems & Department of Mechanics and {2. Science Peking University Beijing 100871 China

From point of view of physics, especially of mechanics, we briefly introduce fractional operators (with emphasis on fractional calculus and fractional differential equa- tions) used for describing intermediate processes and critical phenomena in physics and mechanics, their progress in theory and methods and their applications to modern me- chanics. Some authors’ researches in this area in recent years are included. Finally, prospects and evaluation for this subject are made.

关键词： fractional operators,intermediate processes,critical phenomena,modern mechanics

Radiance-based color calibration for image-based modeling with multiple cameras

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Science China(Information Sciences) 2012年第7期55卷 1509-1519页

作者： ZHAO Xu 1,2.,ZHOU Zhong 1,2.& WU Wei 1,2.1 state key {2. of Virtual Reality Technology and Systems,Beihang {2.,beijing 100191,China 2.School of Computer Science and engineering,Beihang {2.,beijing 100191,China 1. state key {2. of Virtual Reality Technology and Systems Beihang University Beijing 100191 China2. School of Computer Science and Engineering Beihang University Beijing 100191 China

Photo-consistency estimation is an important part for many image-based modeling *** paper presents a novel radiance-based color calibration method to reduce the uncertainty of photo-consistency estimation across multiple *** idea behind our method is to convert colors into a uniform radiometric color space in which multiple image data are *** results demonstrate that our method can achieve comparable color calibration effect without adjusting camera parameters and is more robust than other existing ***,we obtain an auto-determined threshold for photo-consistency check,which will lead to a better performance than existing photo-consistency based reconstruction algorithms.

关键词： color calibration photo-consistency estimation multi-camera system image-based modeling

The refined theory of deep rectangular beams based on general solutions of elasticity

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Science China(Physics,Mechanics & Astronomy) 2006年第3期49卷 291-303页

作者： GAO Yang1 & WANG Minzhong2.1. College of Science, China Agricultural university, beijing 100083, China 2. {2. key laboratory for Turbulence and Complex Systems and Department of Mechanics and Engi- neering Science, Peking university, beijing 100871, China College of Science China Agricultural University Beijing 100083 China state key {2. for Turbulence Complex Systems Department of Mechanics engineering Science Peking University Beijing 100871 China

The problem of deducing one-dimensional theory from two-dimensional the- ory for a homogeneous isotropic beam is investigated. Based on elasticity theory, the re- fined theory of rectangular beams is derived by using Papkovich-Neuber solution and Lur’e method without ad hoc assumptions. It is shown that the displacements and stresses of the beam can be represented by the angle of rotation and the deflection of the neutral surface. Based on the refined beam theory, the exact equations for the beam without transverse surface loadings are derived and consist of two governing differential equations: the fourth-order equation and the transcendental equation. The approximate equations for the beam under transverse loadings are derived directly from the refined beam theory and are almost the same as the governing equations of Timoshenko beam theory. In two ex- amples, it is shown that the new theory provides better results than Levinson’s beam the- ory when compared with those obtained from the linear theory of elasticity.

关键词： deep rectangular beams,the refined theory,Papkovich-Neuber solution,Lur'e method,governing equation

A COUPLED 1-D AND 2.D CHANNEL NETWORK MATHEMATICAL MODEL USED FOR FLOW CALCULATIONS IN THE MIDDLE REACHES OF THE YANGTZE RIVER

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Journal of Hydrodynamics 2011年第4期23卷 521-526页

作者： HAN Dong FANG Hong-wei BAIJing HE Guo-jian Department of hydraulic engineering and {2. key laboratory of Hydroscience and engineering Tsinghua University Beijing 100084 China

A coupled one-dimensional （1-D） and two-dimensional （2.D） channel network mathematical model is proposed for flow calculations at nodes in a channel network system in this article. For the 1-D model, the finite difference method is used to discretize the Saint-Venant equations in all channels of a looped network. The Alternating Direction Implicit （ADI） method is adopted for the 2.D model at the nodes. In the coupled model, the 1-D model provides a good approximation with small computational effort, while the 2.D model is applied for complex topography to achieve a high accuracy. An Artificial Neural Network （ANN.） method is used for the data exchange and the connectivity between the 1-D and 2.D models. The coupled model is applied to the Jingjiang-Dongting Lake region, to simulate the tremendous looped channel network system, and the results are compared with field data. The good agreement shows that the coupled hydraulic model is more effective than the conventional 1-D model.

关键词： Coupled 1-D and 2.D model looped channel network system Alternating Driection Implicit (ADI) Jingjiang-Dongting Lake region