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Nonlinear properties of fractal growth of thin films at low temperature

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Communications in Nonlinear science and Numerical Simulation 2001年第2期6卷 61-67页

作者： Fengmin WU, Jiefang ZHANG, Gen BIAN and Ziqin WU Research Center of science, zhejiang university of technology, hangzhou 310014, china Institute of Nonlinear Physics, zhejiang Normal university, Jinhua 321004, china Shao Yifu Hospital of zhejiang Provin Research Center of science Zhejiang University of Technology Hangzhou 310014 China Institute of Nonlinear Physics Zhejiang Normal University Jinhua 321004 China Shao Yifu Hospital of zhejiang Province Hangzhou 310005 China department of Astronomy and Applied Physics University of Science and Technology of China Hefei 230026 China

Fractal growth of thin films at low temperature (75-200 K) is simulated by kinetic Monte Carlo method, using realistic growth model-Ag on Pt(111) surface and physical parameters. It is shown that the fractal growth of thin films is nonlinear, i. e., the island size S(t) grows with time t as tk ) where the growth exponent k is slightly less than 1 because of the growth competition of islands and the competition between nucleation and growth of islands. The further results indicate that the branch width of islands b increases with increasing island size S as b -Sa, where a is approximately equal to 1/3 because of the geometrical structure of the triangular substrate.

关键词： fractal growth thin film Monte Carlo method

Effect of background electrolytes on the adsorption of nitroaromatic compounds onto bentonite

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Journal of Environmental sciences 2009年第8期21卷 1044-1052页

作者： CHEN Baoliang, HUANG Wenhai department of Environmental science, zhejiang university, hangzhou 310028, zhejiang, china. [a]department of Environmental science Zhejiang University Hangzhou 310028 Zhejiang China

To further elucidate interaction of nitroaromatic compounds with mineral surface, the sorption of m-dinitrobenzene （m-DNB） and nitrobenzene to original bentonite in aqueous solution containing different electrolytes （i.e., KCl, NH4Cl, CaCl2 and Tetramethylammonium bromide （TMAB）） was studied. The sorption of m-DNB was greatly enhanced with the presence of KCl and NH4Cl, while little influence was observed with CaCl2 and TMAB, following the order of KCl 〉 NH4Cl 〉〉 TMAB, CaCl2, or DI water. For nitrobenzene, sorption enhancement only occurred at high nitrobenzene concentrations in the presence of KCl, and the solute equilibrium concentration at inflexion point was lowered with increasing KCl concentration. These sorption enhancements were significantly promoted with the increase of electrolyte concentration. The salting-out effect is insufficient to account for the sorption enhancement by original bentonite with increasing KCI or NH4Cl concentration. X-ray diffraction patterns of bentonite suspensions indicated that the sorption enhancement of m-DNB was attributed to the intercalation of K^＋ or NH4^＋ into bentonite interlayer and then dehydration with m-DNB to form inner-sphere complexes, which caused previously expanded bentonite interlayers to collapse in aqueous suspension, thus further enhanced the interaction of phenyl with siloxane surface. In comparison, the sorption enhancement of NB is attributed to the formation of outer-sphere complexes with K^＋ at high solute-loadings （〉 20（0-400 mg/kg）. The sorption of m-DNB to initially modified TMA^＋-bentonite and K^＋-bentonite was almost the same as respective sorption to original bentonite in solution containing TMA^＋ and K^＋.

关键词： sorption nitroaromatic compound bentonite cation type wastewater treatment

A secure multi-party computation solution to intersection problems of sets and rectangles

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Progress in Natural science:Materials International 2006年第5期16卷 538-545页

作者： LI Shundong, DAI Yiqi, WANG Daoshun and LUO Ping (department of computer science and technology, Beijing Normal university, Beijing 100875, china department of computer science and technology, Tsinghua university, Beijing 100084, china) [a]department of computer science and technology Beijing Normal University Beijing China [b]department of computer science and technology Tsinghua University Beijing China

Secure multi-party computation (SMC) is a research focus in international cryptographic community. At present, there is no SMC solution to the intersection problem of sets. In this paper, we first propose a SMC solution to this problem. Applying Cantor encoding method to computational geometry problems, and based on the solution to set-intersection problem, we further propose solutions to points inclusion problem and intersection problem of rectangles and further prove their privacy-preserving property with widely accepted simulation paradigm. Compared with the known solutions, these new solutions are of less computational complexity and less communication complexity, and have obvious superiority in computational and communication complexity.

关键词： Cantor encoding secure multi-party computation set-intersection rectangle-intersection computational complexity.

An efficient and DoS-resistant user authentication scheme for two-tiered wireless sensor networks

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Journal of zhejiang university-science C(computers and Electronics) 2011年第7期12卷 550-560页

作者： Rong FAN ,Dao-jing HE ,Xue-zeng PAN,Ling-di PING (School of computer science and technology,zhejiang university,hangzhou 310027,china) School of computer science and technology Zhejiang University

Wireless sensor networks (WSNs) are vulnerable to security attacks due to their deployment and resource *** that most large-scale WSNs follow a two-tiered architecture,we propose an efficient and denial-of-service (DoS)-resistant user authentication scheme for two-tiered *** proposed approach reduces the computational load,since it performs only simple operations,such as exclusive-OR and a one-way hash *** feature is more suitable for the resource-limited sensor nodes and mobile *** it is unnecessary for master nodes to forward login request messages to the base station,or maintain a long user *** addition,pseudonym identity is introduced to preserve user *** clever design,our proposed scheme can prevent smart card ***,security and performance analysis demonstrates the effectiveness and robustness of the proposed scheme.

关键词： User authentication User anonymity Smart card Two-tiered Wireless sensor network (WSN)

Surface electromagnetic modes contribution to the anomalous terahertz transmission through double-layered metal hole array

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science china(Information sciences) 2012年第1期55卷 90-97页

作者： RAO Lei1&YANG DongXiao1,2 1department of Information science and Electronic Engineering,zhejiang university,hangzhou 310027,china 2Research Center for Terahertz technology,zhejiang university,hangzhou 310027,china 1. department of Information science and Electronic Engineering Zhejiang University Hangzhou 310027 China2. Research Center for Terahertz Technology Zhejiang University Hangzhou 310027 China

Terahertz transmission spectra through both single-layered and double-layered sub-wavelength metal hole arrays were calculated using rigorous mode-matching *** dispersion relations of the single-layered and double-layered metal hole arrays were obtained by FDTD *** are three anomalous peaks in the spectrum of the double-layered metal hole array,which arise from the three surface electromagnetic modes appearing in the dispersion *** comparing the transmission spectra and the dispersion relations of the single-layered and double-layered metal hole arrays,it was found that the two surface electromagnetic modes at higher frequencies are introduced by the single-layered metal hole array,while the one at lower frequencies is introduced by the double-layered metal hole *** validity of the analysis was qualitatively verified by the experimental *** structure can be finely designed for potential applications,such as wideband filtering.

关键词： surface electromagnetic modes double-layered metal hole array terahertz

Perturbations of the Yang-Mills field in the universe

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Research in Astronomy and Astrophysics 2009年第8期9卷 874-882页

作者： Wen Zhao1,2 1 department of Physics, zhejiang university of technology, hangzhou 310014, china W 2 School of Physics and Astronomy, Cardiff university, Cardiff, CF24 3AA, United Kingdom department of Physics Zhejiang University of Technology Hangzhou 310014 China School of Physics and Astronomy Cardiff University Cardiff CF24 3AA United Kingdom

It has been suggested that the Yang-Mills （YM） field can be a kind of candidate for the inflationary field at high energy scales or dark energy at very low energy scales, which can naturally give the equation of state - 1 〈 ω 〈 0 or ω 〈 - 1. We discuss the zero order and first order Einstein equations and YM field kinetic energy equations of the free YM field models. From the zero order equations, we find that w ＋ 1 ω α^-2, from which it follows that the equation of state of the YM field always goes to - 1, independent of the initial conditions. By solving the first order Einstein equations and the YM field equations, we find that in the YM field inflationary models, the scale-invariant primordial perturbation power spectrum cannot be generated. Therefore, only using this kind of YM field is not enough to account for inflationary sources. However, as a kind of candidate for dark energy, the YM field has the ＇sound speed＇ c^28 = -1/3 〈 0, which makes the perturbation Ф have a damping behavior at large scales. This provides a way to distinguish the YM field dark energy models from other kinds of models.

关键词： cosmology theory- gravitation- methods analytical

Tissue P systems with parallel rules on channels

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Progress in Natural science:Materials International 2007年第4期17卷 486-491页

作者： Xu Xian (department of computer science and technology, Shanghai Jiao Tong university, Shanghai 200240, china) [a]department of computer science and technology Shanghai Jiao Tong University Shanghai China

A new variant of P systems as an improvement of the original design is introduced. The P systems here allow parallelism in rules application on synapses (or links, channels), rendering the systems more efficient. We describe the execution mechanism of our P systems, make analysis on its computation power, and illustrate the running by an example.

关键词： tissue P systems parallel rules.

CRYSTAL STRUCTURE AND ELECTROCHEMICAL PROPERTIES OF Zr(Mn_(1-x)Ni_x)_2(0.40≤x≤0.75) HYDROGEN STORAGE ALLOYS

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Acta Metallurgica Sinica(English Letters) 2001年第1期14卷 56-62页

作者： W.K. Zhang, C.A. Ma, X.G. Yang, H. Huang, Y.Q. Lei and Q.D. Wang (department of Applied Chemistry, zhejiang university of technology, hangzhou 310014, china department of Materials science and Engineering, zhejiang university, hangzhou 310027, china) Dept. of Appl. Chem. Zhejiang Univ. of Technol. Hangzhou 310014 China

The crystal structure, phase abundance and the electrochemical properties of Zr(Mn1-x Nix)2 (0.40 ≤x≤0.75) alloys were investigated by means of XRD, Rietveld refinement method and electrochemical measurements. The alloys are multiphase. C15 Laves phase occurs as a main phase accompanying with C14 phase and other minor phases, indicating that Ni element is C15-stabilized element for ZrMn2 alloy. The phase abundance and lattice parameters of Laves phase are influenced significantly by Ni substitution. The Zr(Mn0.45 Ni0.55)2 alloy with the highest amount of C15 phase exhibits the maximum electrochemical capacity of 242m Ah/g. C14 phase occurring in Zr-Mn-Ni alloys is beneficial for the electrochemical kinetics of hydride electrodes.

关键词： hydrogen storage alloy crystal structure phase abundance,elec- trochemical property

Compactness in fuzzy logic

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Chinese science Bulletin 1998年第14期43卷 1166-1171页

作者： YING Mingsheng department of computer science and technology, Tsinghua university, Beijing 100084, china department of computer science and technology Tsinghua University Beijing China

Compactness in Pavelka’s fuzzy logic for some compact lattices of truth values is shown, and the concept of gradual compactness is introduced to establish some corresponding results in a more general setting.

关键词： fuzzy logic compactness gradual compactness.