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Total variance and invariant information in complementary measurements

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Communications in Theoretical Physics 2020年第6期72卷 65-69页

作者： bin chen Shao-Ming Fei College of Mathematical Science Tianjin Normal UniversityTianjin 300387China School of Mathematical Sciences Capital Normal UniversityBeijing 100048China Max-Planck-Institute for Mathematics in the Sciences D-04103 LeipzigGermany

We investigate the total variance of a quantum state with respect to a complete set of mutually complementary measurements and its relation to the Brukner–Zeilinger invariant *** summing the variances over any complete set of mutually unbiased measurements and general symmetric informationally complete measurements respectively,we show that the Brukner–Zeilinger invariant information associated with such types of quantum measurements is equal to the difference between the maximal variance and the total variance *** results provide an operational link between the previous interpretations of the Brukner–Zeilinger invariant information.

关键词： total variance mutually complementary measurements Brukner–Zeilinger invariant information

Two-Flux Colliding Plane Waves in String Theory

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Communications in Theoretical Physics 2005年第3X期44卷 463-472页

作者： chen bin ZHANG Jun-Feng Department of Physics Peking University Beijing 100871 China Department of Mathematics Capital Normal University Beijing 100037 China

We construct the two-flux colliding plane wave solutions in higher-dimensional gravity theory with dilaton,and two complementary fluxes. Two kinds of solutions have been obtained: Bell-Szekeres (BS) type and homogeneous type. After imposing the junction condition, we find that only the BS type solution is physically well-defined. Furthermore, we show that the future curvature singularity is always developed for our solutions.

关键词： colliding plane wave string theory

Average coherence with respect to complementary measurements

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Communications in Theoretical Physics 2021年第1期73卷 35-39页

We investigate the average coherence with respect to a complete set of complementary *** using a Wigner-Yanase skew information-based coherence measure introduced in Luo and Sun(2017 ***.A 96,022130),we evaluate the average coherence of a state with respect to any complete set of mutually unbiased measurements and general symmetric informationally complete measurements,*** also establish analytically the relations among these average coherences.

关键词： average coherence mutually unbiased measurements general symmetric informationally complete measurements

Fast Image Coding Algorithm Using Indirect-Index Codebook Based on SMVQ

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Journal of Electronic Science and Technology 2016年第2期14卷 183-190页

作者： bin-bin Xia An-Hong Wang Chin-chen Chang Li Liu College of Electronic Information and Engineering Taiyuan University of Science and TechnologyTaiyuan Department of Information Engineering and Computer Science Feng Chia University

Side-match vector quantization （SMVQ） achieves better compression performance than vector quantization （VQ） in image coding due to its exploration of the dependence of adjacent pixels. However, SMVQ has the disadvantage of requiring excessive time during the process of coding. Therefore, this paper proposes a fast image coding algorithm using indirect-index codebook based on SMVQ （IIC-SMVQ） to reduce the coding time. Two codebooks, named indirect-index codebook （II-codebook） and entire-state codebook （ES-codebook）, are trained and utilized. The II-codebook is trained by using the Linde-Buzo-Gray （LBG） algorithm from side-match information, while the ES-codebook is generated from the clustered residual blocks on the basis of the II-codebook. According to the relationship between these two codebooks, the codeword in the II-codebook can be regarded as an indicator to construct a fast search path, which guides in quickly determining the state codebook from the ES-codebook to encode the to-be-encoded block. The experimental results confirm that the coding time of the proposed scheme is shorter than that of the previous SMVQ.

关键词： Entire-state codebook indirect-indexcodebook Linde-Bnzo-Gray side-match vectorquantization.

Notes on index of quantum integrability

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Communications in Theoretical Physics 2021年第5期73卷 1-9页

作者： Jia Tian Jue Hou bin chen School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking UniversityNo.5 Yiheyuan RdBeijing 100871China Center for High Energy Physics Peking UniversityNo.5 Yiheyuan RdBeijing 100871China Collaborative Innovation Center of Quantum Matter No.5 Yiheyuan RdBeijing 100871China

A quantum integrability index was proposed in Komatsu et al(2019 SciPost Phys.7065).It systematizes the Goldschmidt and Witten's operator counting argument(Goldschmidt and Witten 1980 ***.B 91392)by using the conformal *** this work we compute the quantum integrability indexes for the symmetric coset models SU(N)/SO(N)and SO(2N)/SO(N)×SO(N).The indexes of these theories are all non-positive except for the case of SO(4)/SO(2)×SO(2).Moreover we extend the analysis to the theories with fermions and consider a concrete theory:the CP~N model coupled with a massless Dirac *** find that the indexes for this class of models are non-positive as well.

关键词： integrability quantum index coset models

Behavior of SiO_2 in the leaching process of alumina clinker with high concentration

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Journal of University of Science and Technology Beijing 2008年第5期15卷 538-542页

作者： bin chen Xiaobin Li Guihua Liu School of Metallurgical Science and Engineering Central South University Changsha 410083 China

It is essential for alumina production by alkaline process to know the behavior of minerals containing Al and Si in basic solution,and the behavior of SiO2 in the process of clinker leaching is an important portion. To study the behavior of SiO2 in the process of high concentration clinker leaching,experiments were carried out in home-made reactors. The results indicate that factors,such as temperature,time,Al2O3 concentration,as well as SiO2 concentration,have profound impact on the SiO2 and Al2O3 concen-tration of pregnant liquor during the high concentration leaching. However,sodium carbonate and free caustic soda concentrations have no remarkable effect on it,thus they are the secondary factors compared with Al2O3 concentration. The concentration of SiO2 in the pregnant liquor could be reduced to a lower level when the major effect parameters of this process are controlled properly.

关键词： clinker leaching high concentration silica mechanism of secondary reaction

Microstructure and properties of joint for stirring brazing of dissimilar Al/Mg alloy during heating processes

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Rare Metals 2015年第4期34卷 245-250页

作者： Hui-bin Xu Hui-bin Sun Hui Yang Lu-Xin Chi Jun chen School of Materials Science and Engineering Chongqing University of Technology

In this paper, 2024 Al alloy and AZ31B Mg alloy were brazed with aid of stirring without flux in air. The effects of the brazing temperature on microstructure and shear strength of the joint were investigated. The diffusion zone is found at joint interface near Al base metal, which consists of Al-Zn-Sn solid solution. At the same time, continuous intermetallic compounds （IMCs） phase and broken ones are found at joint interface near Mg base metal, which mainly consists of the Mg2Sn phase. With the increase of the brazing temperature, the shear strength at the joint interface near A1 base metal rises gradually. On the contrary, that of the joint interface near Mg base metal obviously decreases.

关键词： Stirring brazing 2024 Al alloy AZ31B Mg alloy Temperature

ShadowEth： Private Smart Contract on Public Blockchain

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Journal of Computer Science & Technology 2018年第3期33卷 542-556页

作者： Rui Yuan Yu-bin Xia Hai-Bo chen bin-Yu Zang Jan Xie Institute of Parallel and Distributed Systems Shanghai Jiao Tong University Shanghai 200240 China Cryptape Inc. Hangzhou 310007 China

Blockchain is becoming popular as a distributed and reliable ledger which allows distrustful parties to transact safely without trusting third parties. Emerging blockchain systems like Ethereum support smart contracts where miners can run arbitrary user-defined programs. However, one of the biggest concerns about the blockchain and the smart contract is privacy, since all the transactions on the chain are exposed to the public. In this paper, we present ShadowEth, a system that leverages hardware enclave to ensure the confidentiality of smart contracts while keeping the integrity and availability based on existing public blockchains like Ethereum. ShadowEth establishes a confidential and secure platform protected by trusted execution environment （TEE） off the public blockchain for the execution and storage of private contracts. It only puts the process of verification on the blockchain. We provide a design of our system including a protocol of the cryptographic communication and verification and show the applicability and feasibility of ShadowEth by various case studies. We implement a prototype using the Intel SGX on the Ethereum network and analyze the security and availability of the system.

关键词： blockchain smart contract privacy trusted execution environment hardware-enclave

Deformed integrable models from holomorphic Chern-Simons theory

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Science China(Physics,Mechanics & Astronomy) 2022年第10期65卷 53-74页

作者： Yi-Jun He Jia Tian bin chen School of Physics Peking UniversityBeijing 100871China Collaborative Innovation Center of Quantum Matter Beijing 100871China Center for High Energy Physics Peking UniversityBeijing 100871China Kavli Institute for Theoretical Sciences(KITS) University of Chinese Academy of SciencesBeijing 100190China

We study the approaches to two-dimensional integrable field theories via a six-dimensional(6 D) holomorphic Chern-Simons theory defined on twistor space. Under symmetry reduction, it reduces to a 4 D Chern-Simons theory, while under solving along fibres it leads to a four-dimensional(4 D) integrable theory, the anti-self-dual Yang-Mills or its generalizations. From both 4 D theories, various two-dimensional integrable field theories can be obtained. In this work, we try to investigate several twodimensional integrable deformations in this framework. We find that the λ-deformation, the rational η-deformation, and the generalized λ-deformation can not be realized from the 4 D integrable model approach, even though they could be obtained from the 4 D Chern-Simons theory. The obstacle stems from the incompatibility between the symmetry reduction and the boundary conditions. Nevertheless, we show that a coupled theory of the λ-deformation and the η-deformation in the trigonometric description could be obtained from the 6 D theory in both ways, by considering the case that(3, 0)-form in the 6 D theory is allowed to have zeros.

关键词： integrable systems gauge field theories classical field theories

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