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Hot Corrosion of Iron in the Presence of Salt Mixture Deposit Containing NaCl and V_2O_5 at 600℃

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Journal of Materials science & technology 1996年第6期12卷 445-451页

作者： Lingchuan LI (Dept. of Materials science and Engineering, tsinghua university beijing 100084, china)Rizhang ZHU (Dept. of Surface science and Corrosion Engineering, university of science and technology beijing, beijing 100083, china)(To whom correspondenc Dept. of Materials science and Engineering Tsinghua University Beijing 100084 China Dept. of Surface science and Corrosion Engineering University of Science and Technology Beijing Beijing 100083 China Instiuto di Chimica Facolta di Ingegneria Università di Genova Fiera del Mare Pad.D 16129 Genova Italy

Iron suffered low temperature hot corrosion (LTHC) in the presence of salt deposits of Na2SO4,Na2SO4 mixed with NaCl and Na2SO4 mixed with V2O5 in a combustion gas at 600℃. The additions of NaCl to Na2SO4 and of V2O5 to Na2SO4 changed the corrosion kinetics significantly and modified the scale structure markedly It is proposed that trivalent iron ions were more favored than divalent ions in the eutectic responsible for the occurrence of LTHC when NaCl was present, while the reaction between Na2SO4 mixed with V2O5 and the gas formed (Na2O)xV2O4(V2O5)6-x providing directly the liquid required by LTHC. The suphide formation in the inner FeO larer was related to the sites of the reduction step wher SO2 was released.

关键词： SO NaCl

Remarks on the bounds for cryptanalysis of low private key RSA

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Progress in Natural science:Materials International 2009年第10期19卷 1327-1331页

作者： Haijian Zhou a,Ping Luo b,Daoshun Wang a,Yiqi Dai a a department of computer science and technology,tsinghua university,beijing 100084,china b School of Software,tsinghua university,beijing 100084,china [a]department of computer science and technology Tsinghua University Beijing 100084 China [b]School of Software Tsinghua University Beijing 100084 China

Boneh and Durfee have developed a cryptanalytic algorithm on low private key *** algorithm is based on lattice basis reduction and breaks RSA with private key d < N0:*** on,an improved version by Blmer and May enhan... 详细信息

Boneh and Durfee have developed a cryptanalytic algorithm on low private key *** algorithm is based on lattice basis reduction and breaks RSA with private key d 4-bit public key eN;eT.

关键词： RSA Cryptanalysis Low private key Lattice basis reduction

Theorems for Testing Local Activity of CNN and Application to Cardiac Purkinje Equations

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International Journal of Minerals,Metallurgy and Materials 2000年第2期14卷 139-146页

作者： Lequan Min(Applied science School, university of science and technology beijing, beijing 100083, china) Applied science School University of Science and Technology Beijing Beijing 100083 China

The theorems for testing the local in one-port cellular neural/inear network (CNN) cells with four local state variables are presented. Using the theorems computes the bifurcation diagrams of the cardiac Purkinje fiber (CPE) equations Which describethe long-lasting action and pace-maker potentials of the Purkinje fiber of the heart. The computer simulation shows that periodic trajectories or convergent trajectories of the CPF Equations can be foun if the cormsponing cell Parameters are located in a positive domainbut nearby edge of chaos. In particular a heart with approximate normal frequency of heartbeat but non-normal electrocardiogram maysuddenly stop by slightly perturbing the parameters of the corresponding CPF Equations when the Paramders are located nearby the edge of chaos in the bifurcation diagrams. This research seems to interpret reasonbly the phenomena that patients with cardiac diseases might suddenly die without warning.

关键词： cellular neural network local activity cardiac Purkinje fiber heartbeat

Entropy number and non-linear approximations on multivariate Besov space by manifolds of finite pseudo-dimension

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Progress in Natural science:Materials International 2006年第3期16卷 260-265页

作者： LONG Jingfan and FANG Gensun (School of Mathematical sciences, beijing Normal university, beijing 100875, china department of computer science, information technology Institute, beijing 100101, china) [a]School of Mathematical sciences Beijing Normal University Beijing China [b]department of computer science Information Technology Institute Beijing China

We determine the asymptotic order of entropy number and optimal non -linear approximations of anisotropic periodic Besov class of Bpθr(Td') (1≤p≤∞,1≤0≤∞) by manifolds of finite pseudo-dimension in the metric Lq... 详细信息

关键词： Pseudo-dimension anisotropic Besov class of functions entropy number nonlinear width.

Arbitrarily long distance quantum communication using inspection and power insertion

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Chinese science Bulletin 2009年第1期54卷 158-162页

作者： WANG WanYing1,2,WANG Chuan1,2,ZHANG GuangYu1,3 & LONG GuiLu1,2 1 department of Physics,tsinghua university,beijing 100084,china 2 tsinghua National Laboratory for information science and technology,tsinghua university,beijing 100084,china 3 college of Applied science,Harbin university of science and technology,Harbin 150080,china department of Physics Tsinghua University Beijing 100084 China tsinghua National Laboratory for information science and technology Tsinghua University Beijing 100084 China college of Applied science Harbin University of Science and Technology Beijing 100084 China

The biggest obstacle for long distance quantum communication is the channel loss and the channel noise on photons. In this paper,a method to solve this problem was analyzed using inspection and power insertion (IPI). It is proved that quantum communication may be established over arbitrarily long distance using this technology. The amount of resources required is a polynomial function of the dis-tance. IPI is proposed as a general technique to prolong quantum secure direct communication where secret messages are transmitted directly over a quantum channel.

关键词：长距离量子通信量子安全通信量子密匙分布噪声

Generalized gradient projection neural networks for nonsmooth optimization problems

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science china(information sciences) 2010年第5期53卷 990-1005页

作者： LI GuoCheng 1 , SONG ShiJi 2 ? & WU Cheng 2 1 department of Mathematics, beijing information science and technology university, beijing 100192, china 2 department of Automation, tsinghua university, beijing 100084, china 1. department of Mathematics Beijing Information Science and Technology University Beijing 100192 China2. Department of Automation Tsinghua University Beijing 100084 China

Generalized gradient projection neural network models are proposed to solve nonsmooth convex and nonconvex nonlinear programming problems over a closed convex subset of R n . By using Clarke’s generalized gradient, the neural network modeled by a differential inclusion is developed, and its dynamical behavior and optimization capabilities both for convex and nonconvex problems are rigorously analyzed in the framework of nonsmooth analysis and the differential inclusion theory. First for nonconvex optimization problems, the quasi convergence results similar to those achieved by previous work are proved. For convex optimization problems, the global convergence results are proved, i.e. any trajectory of the neural network converges to an asymptotically stable equilibrium point, which is an optimal solution of the primal problem whenever it exists. This result remains valid even if the initial condition is chosen outside the feasible set. In addition, an asymptotic control result involving a Tykhonov like regularization shows that any trajectory of the revised neural network can be forced to converge toward a particular optimal solution of the primal problem. Finally, two simulation optimization algorithms for solving the optimization and control problems are designed respectively, and three typical simulation experiments are illustrated to present the accuracy and efficiency of theoretical convergence results of this paper.

关键词： nonsmooth optimization problem generalized gradient projection networks differential inclu sions convergence

TEM OBSERVATION OF LOCAL DEFORMATION BAND AT CRACK TIP

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Acta Metallurgica Sinica(English Letters) 1992年第3期5卷 147-153页

作者： YAO Kefu university of science and technology beijing,beijing,chinaTANG Naivong CHEN Nanping tsinghua university,beijing,china beijing Univ of science and Technology Beijing China

The thin foil specimen of a ferrite-austenite duplex stainless steel was tensiled under transmis- sion electron microscope(TEM).It was found that both in ferrite and austenite the local deformation band at crack tip was formed near to the crack propagating *** forma- tion was related with the crack tip Schmid factor,dislocation shielding,latent hardening and hardening *** the crack tip emitted dislocations to a slip system by the action of pure mode Ⅱ stress resolute,and the decreasing rate of hardening coefficient was suitable,lo- cal deformation band was easy to form.

关键词： crack tip local deformation band dislocation shielding

Expression of lignin peroxidase H2 from Phanerochaete chrysosporium by multi-copy recombinant Pichia strain

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Journal of Environmental sciences 2009年第2期21卷 218-222页

作者： WANG Wei,WEN Xianghua department of Environmental science and Engineering,tsinghua university,beijing 100084,china. department of Environmental science and Engineering Tsinghua University Beijing 100084 China

The lipH2 gene, encoding the expression of lignin peroxidase, was cloned from Phanerochaete chrysosporium BKM-F-1767 and expressed in Pichia pastoris X-33, a yeast. The cDNA of LiPH2 was generated from total RNA extracted from P chrysosporium by PCR with primers that do not contain a P. chrysosporium lignin peroxidase secretion signal. The gene was then successfully inserted into the expression vector pPICZα, and resulted in the recombinant vector pPICZα-lipH2. The transformation was conducted in two ways. One was using the wild Pichia pastoris as the recipients, which results in the recombinant P. pastoris with single or low lipH2 gene copy. The second was using P. pastoris and single or low lipH2 gene copy as the recipients, which results in the recombinant P. pastoris with multi-copies of lipH2 genes. This study firstly expressed the gene lipH2 in P. pastoris and achieved the successful expression of the lipH2 depending upon the generation of a recombinant strain that contained multiple copies. The lignin peroxidase activity reached a maximum of 15 U/L after 12 h induction.

关键词： heterologous expression lignin peroxidase Pichia pastoris

NON-EQUILIBRIUM SEGREGATION OF Si ON Al-0.35 wt-% Si ALLOY SURFACE

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Acta Metallurgica Sinica(English Letters) 1993年第8期6卷 98-101页

作者： CHEN Niug YU Zongsen university of science and technology beijing,beijing,china professor,department of Materials Physics,university of science and technology beijing,beijing 100083,china beijing Univ of science and Technology Beijing China

Si segregation was observed in the vacancy condensation pits,formed by supersaturated vacancies beneath the oxidation layer of Al-0.35wt-％Si alloy,by optical microscopy,X- ray photoelectron spectroscopy and microhard... 详细信息

关键词： non-equilibrium segregation vacancy AI-Si alloy surface Si