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Large second-order optical nonlinearities of s-triazine derivatives: View from micro molecules to macro crystals

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Science china Chemistry 2005年第3期48卷 203-209页

作者： FANG Qi1, LEI Hong2, CUI Yuezhi3, HUANG Zhenli4, XUE Gang1 & YU Wentao1 1. state key laboratory of Crystal Materials, Shandong university, Jinan 250100, china 2. School of information Science and engineering, Shandong university, Jinan 250100, china 3. Department of Chemical engineering, Light Industry College of Shandong, Jinan 250100, china 4. key laboratory of Biomedical Photonics, Ministry of Education, Huazhong university of Science and Technology, wuhan 430074, china 1. state key laboratory of Crystal Materials Shandong University 250100 Jinan China 2. School of information Science and engineering Shandong University 250100 Jinan China 3. Department of Chemical engineering Light Industry College of Shandong 250100 Jinan China 4. key laboratory of Biomedical Photonics Ministry of Education Huazhong University of Science and Technology 430074 Wuhan China

Three s-triazine derivatives have been synthesized and their structures been de-termined. These are Compound I: 2,4-dimethyl-6-(p-N,N-dimethylaminostyryl)-s-triazine (abbre-viated to NMe-1), Compound II: 2,4-dimethyl-6-(p-N,N-diethylaminostyryl)-s-triazine (to NEt-1), and Compound III: 2-methyl-4,6-bis(p-N,N-dimethylaminostyryl)-s-triazine (NMe-2). NMe-1 and NEt-1 molecules belong to the D-π-A type with a one-dimensional charge-transfer character. NMe-1 crystallizes to centrosymmetric P1 space group, while NEt-1 to non-centrosymmetric polar Cc space group with all of the molecular charge-transfer axes taking the same orientation. Under the irradiation of 1064 nm fundamental laser, NEt-1 powder crystals radiate a 2-order harmonic light with an intensity 46.8 times that of urea. The Λ typed NMe-2 molecule, which has a two-dimensional charge-transfer character, crystallizes to polar P21 space group. Its powder crystals exhibit a 2-order harmonic intensity 46.2 times that of urea. The quantum chemical cal-culations and tensor analyses have been carried out to reveal the dependence of the macro 2-order nonlinear optical (NLO) efficiency on the micro 2-order NLO coefficients (β) and on the crystalline packing styles.

关键词： s-triazine derivatives, synthesis, structure, SHG intensities of crystals, βvalues of molecules.

Polar differential power attacks and evaluation

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Science china(information Sciences) 2012年第7期55卷 1588-1604页

作者： TANG Ming 1 ,QIU ZhenLong 1 ,GAO Si 1,2 ,YI Mu 3 ,LIU ShuBo 1 ,ZHANG HuanGuo 1 & JIN YingZhen 1 1 School of Computer Science,wuhan university,wuhan 430072,china 2.state key laboratory of information Security,Institute of Software,Chinese Academy of Sciences,Beijing 100190,china 3 Centre for Computer and information Security Research School of Computer Science and Software engineering university of Wollongong,Wollongong,NSW 2522,Australia 1. School of Computer Science Wuhan University Wuhan 430072 China2. State Key Laboratory of Information Security Institute of Software Chinese Academy of Sciences Beijing 100190 China3. Centre for Computer and Information Security Research School of Computer Science and Software Engineering University of Wollongong Wollongong NSW 2522 Australia

Side channel attacks (SCAs) on security software and hardware have become major concerns on computer and system *** existing SCAs generally require the knowledge of the corresponding cryptographic algorithm and implementation adopted in the target; therefore,they are not fully suitable for practical *** this paper,we propose a novel SCA-polar differential power attack (polar DPA).We found that DPA peaks have different biases for different cryptographic algorithms and *** on these biases,we can successfully attack a block cipher,assuming that the cipher algorithm uses a secret key in its first round,without the knowledge of the cipher algorithm or *** rounds can be treated as a black *** present a detailed theoretical analysis and experiment to demonstrate the correctness and efficiency of our ***,our scheme has demonstrated an improvement over the leakage evaluation scheme due to Ichikawa et al.(CHES 2005).Our evaluation method can be used in electronic design automatic (EDA) flows and can help security circuit designers to understand the data leakage due to SCAs.

关键词： computer security differential power attack side channel attack

Conceptual design,data model and key techniques of“3D Assistant”

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中国有色金属学会会刊：英文版 2011年第S3期21卷 692-698页

作者： LI Qing-yuan1, ZHANG Xuan2, JIN Yang2, ZHOU Hui3, WANG Qian-jin3,WEI Zhan-yin1 1. key laboratory of Geo-Informatics, Chinese Academy of surveying and mapping, Beijing 100830, china 2. School of Geo-Science and surveying engineering, china university of Mining and Technology, Beijing 100083, china 3. School of Geomatics, Liaoning Technical university, Fuxin 123000, china [a] key laboratory of Geo-Informatics Chinese Academy of Surveying and Mapping Beijing 100830 China [b] School of Geo-Science and surveying engineering China University of Mining and Technology Beijing 100083 China [c] School of Geomatics Liaoning Technical University Fuxin 123000 China

Conceptual design, data model and key techniques of "Geo-engineer 3D assistant", an underground 3D GIS oriented to geology and mine application, were discussed. In particular, the importance of high-order smoothing triangular pieces to surface's fine expression in geological modeling was emphasized. The contour mode is the most favorite mode of the three modes about surface expression: DEM, TIN and contour. Topology in underground 3D modeling with CAGD was compared. From the view of boundary and coboundary, which is soul of IS 19107 (Geographic information spatial schema), 3D underground topology was re-examined.

关键词： 3D assistant true 3D GIS fine expression of surface contour mode 3D topology

A Feedback-Based Web Search Engine

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wuhan university Journal of Natural Sciences 2004年第5期9卷 561-568页

作者： ZHANG Wei-feng 1,2,3 , XU Bao-wen 2,3,4 , ZHOU Xiao-yu 2,3,4 1. Department of Computer Science and engineering, Nanjing university of Posts and Telecommunications, Nanjing 210003, Jiangsu, china 2. Department of Computer Science and engineering, Southeast university, Nanjing 210096, Jiangsu, china 3. Jiangsu Institute of Software Quality, Nanjing 210096 Jiangsu, china 4. The state key laboratory of Software engineering, wuhan university, wuhan 430072, Hubei, china Department of Computer Science and engineering Nanjing University of Posts and Telecommunications . Nanjing 210003 Jiangsu China

Web search engines are very useful information service tools in the Internet. The current web search engines produce search results relating to the search terms and the actual information collected by them. Since the selections of the search results cannot affect the future ones, they may not cover most people’s interests. In this paper, feedback information produced by the user’s accessing lists will be represented by the rough set and can reconstruct the query string and influence the search results. And thus the search engines can provide self-adaptability. key words WWW - search engine - query reconstruction - feedback CLC number TP 311. 135.4 Foundation item: Supported by the National Natural Science Fundation of china (60373066). National Grand Fundamental Research 973 Program of china (2002CB31200). Opening Foundation of state key laboratory of Software engineering in wuhan university, Opening Foundation of Jiangsu key laboratory of Computer information Processing Technology in Soochow universityBiography: ZHANG Wei-feng (1975-), male, Ph.D. research direction: artificial intelligence, search engine, data mining, network language.

关键词： WWW search engine query reconstruction feedback

Research on the Earth system multi-body force system dynamical model

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Science china(Technological Sciences) 2006年第z2期49卷 11-22页

作者： CHEN Xiaofei, BI Siwen, WU Fei & DONG Qianlin state key laboratory of remote sensing Science, Jointly Sponsored by the Institute of remote sensing Applications of Chinese Academy of Sciences and Beijing Normal university, Beijing 100101, china laboratory of 3D information Access and Application of Capital Normal university, Beijing 100037, china Chinese Acad Sci Inst Remote Sensing Applicat State Key Lab Remote Sensing Sci Beijing 100101 Peoples R China Beijing Normal Univ Beijing 100101 Peoples R China Capital Normal Univ Lab D Informat Access & Applicat 3 Beijing 100037 Peoples R China

This paper presents an overview of the binding force and freedom force of Earth system, and describes force moment to point and line and force system in the Earth system. It introduces the force theory of the Earth system multi-body force system from special or equivalent force system of Earth system mechanics, general force and no-power force of Earth system. Finally it describes the force and moment of nodes of Earth system and provides basic model for the research of the Earth system multi-body dynamics.

关键词： Earth system, multi-body system force, dynamics, basic models.

A METHOD TO APPROACH OPTIMAL RESTORATION IN IMAGE RESTORATION PROBLEMS WITHOUT NOISE ENERGY information

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Acta Mathematica Scientia 2003年第4期23卷 512-520页

作者：曾三友丁立新康立山 state key laboratory of Software engineering Wuhan University Wuhan 430072 China Deptartment of Computer Science Zhuzhou Institute of Technology Zhuzhou 402008 China state key laboratory of Software engineering Wuhan University Wuhan 430072 China

This paper proposes a new image restoration technique, in which the resulting regularized image approximates the optimal solution steadily. The affect of the regular-ization operator and parameter on the lower band and upper band energy of the residue of the regularized image is theoretically analyzed by employing wavelet transform. This paper shows that regularization operator should generally be lowstop and highpass. So this paper chooses a lowstop and highpass operator as regularization operator, and construct an optimization model which minimizes the mean squares residue of regularized solution to determine regularization parameter. Although the model is random, on the condition of this paper, it can be solved and yields regularization parameter and regularized solution. Otherwise, the technique has a mechanism to predict noise energy. So, without noise information, it can also work and yield good restoration results.

关键词： Regularization method image restoration wavelet transform

Three-dimensional subwavelength components utilizing THz surface plasmons

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Science china(information Sciences) 2012年第1期55卷 79-89页

作者： ZHOU YongJin,JIANG Quan&CUI TieJun state key laboratory of Millimeter Waves,School of information Science and engineering,Southeast university,Nanjing 210096,china 1. state key laboratory of Millimeter Waves School of Information Science and Engineering Southeast University Nanjing 210096 China

Since surface plasmons(SPs)are not constrained by the diraction limit,they have important potential applications in the optical,terahertz(THz),and microwave *** this paper,we firstly present a review of three-dimensional(3D) bidirectional and multi-directional THz SP splitters based on the rectangular metallic groove gratings with finite thickness,in which a metallic wire was used to excite the THz *** experimental verifications of such splitters have been implemented in the microwave frequencies,and the measurement results have excellent agreements to the full-wave *** improve the performance,a 3D bidirectional THz SP splitter with the transverse confinement and a 3D bidirectional bending THz SP splitter are then proposed,which have shown very good splitting performance,compact sizes,and better transverse confinement of EM ***,a broadband slow-wave system of subwavelength thickness is reviewed and a new bending slow-wave system utilizing THz SPs is *** and simulations in microwave frequencies have good agreements,showing the validity of these components.

关键词： surface plasmons surface waves terahertz slow wave splitter

Pair-wise error probability and its Chernoff upper bound for unitary space-time code

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Science china(information Sciences) 2010年第8期53卷 1613-1621页

作者： ZHANG DaPeng 1,2 , LIU Ju 1 , XU HongJi 1 & JI Hui 1 1 School of information Science and engineering, Shandong university, Jinan 250100, china 2.state key laboratory of Integrated Services Networks, Xidian university, Xi’an 710071, china 1. School of information Science and engineering Shandong University Jinan 250100 China2. State Key Laboratory of Integrated Services Networks Xidian University Xi’an 710071 China

Unitary space-time code is ideally suited for rapid fading scenarios as it can operate well without channel state information (CSI), which is of vital significance for improving the effectivity and reliability of wireless communication systems. Pair-wise error probability (PEP) is an important factor for studying the reliability of a communication system. However, the existing scheme only gives the final result of PEP and the corresponding Chernoff upper bound (CUB) is obtained through magnification, which is not of universal significance for this kind of problems. In this paper, we employ the log-likelihood ratio of probability density functions of the received signals conditioned on the two possibly transmitted signals and by virtue of moment generating function we give the details in deriving the final precise residue expression for PEP and its CUB. At last, we verify the above results by simulations.

关键词： multiple-input multiple-output space-time code unitary space-time code pair-wise error probability Chernoff upper bound

A NEW SYNERGIST FOR INTUMESCENT FLAME RETARDANT POLYPROPYLENE

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Chinese Journal of Polymer Science 2002年第4期20卷 377-380页

作者： Qiang Wu 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 synergistic effects of silicotungstic acid (SiW12) as a catalyst in the phosphorus-nitrogen compounds AM-based intumescent flame-retardant (IFR) polypropylene (PP) were studied using the limiting oxygen index (LOI), the UL-94 test, thermogravimetric analysis (TGA), real time Fourier transform infrared (FTIR), laser Raman spectroscopy (LRS). The LOI data show that SiW12 added to PP/IFR systems has a synergistic FR effect with an IFR additive named AM. The TGA data show that SiW12 apparently increases the thermal stability of the PP/IFR systems at high temperature (T > 500degreesC). The FTIR results provide the positive evidence that IFR can improve the thermal stability of PP and SiW12 can induce a higher rate of formation of phosphoric acid and its derivatives. The LRS measurements provide useful information on the carbonaceous microstructures. In short, a suitable amount of SiW12 (1.5 wt%) exerts synergistic effects with the IFR by increasing the LOI value and the thermal stability at high temperature and promoting the formation of charred structures on the burning PP surface.

关键词： silicotungistic acid synergistic effect intumescent flame retardant polypropylene