2008 Vol.14

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E-Euclidean Centralized Localization in Wireless Sensor Networks OUYANG Yu;WANG Chao;SHI Hui-chang Journal of Shanghai University（Natural Science Edition）    2008, 14 (1): 1-6.   Abstract （2514）            Knowledge map    Save We develop an algorithm that computes the Euclidean distance between beacon node and orphan node, estimates the position of orphan node by maximum likely-hood algorithms, and acquires a more precise position by the WLS calculating iteratively. Three methods are given to solve the problems of multihops Euclidean distances. Based on a new opinion over the weighted matrix, the algorithm makes overall plans to look for orphan nodes up to the localization conditions. The orphan node becomes assistant beacon node to aid localization after being localized. Simulation results demonstrate that the average error of positioning is lower and coverage is better when connectivity is 8. Related Articles | Metrics | Comments（0） Cited: Baidu(17)

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A GPS/Gyro Attitude Fusion Algorithm for Marine Application SHA Xiao-ping;CHEN Hui-min;BAO Min-qi;HAN Yi-xin Journal of Shanghai University（Natural Science Edition）    2008, 14 (1): 7-9.   Abstract （2819）            Knowledge map    Save This paper introduces a GPS/single gyro yaw value fusion algorithm for marine application. It first introduces the Runge-Kutta method to estimate the yaw value according to the angular velocity output of gyro. When the GPS signal is output, Kalman filtering is used to estimate yaw value error and bias of gyro to give the accurate value. Simulation results indicate that, by using the fusion algorithm, the final yaw value error is within ±1°. The output is very smooth, indicating that the algorithm is sound and effective. Related Articles | Metrics | Comments（0） Cited: Baidu(2)

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Influence of External-Phase Modulation for SBS on Long-Haul 1550 nm AM-VSB CATV Systems GU Liang-bo;WANG Chun-hua;LI Li Journal of Shanghai University（Natural Science Edition）    2008, 14 (1): 10-14.   Abstract （3709）            Knowledge map    Save External phase modulation is usually applied to improve the SBS threshold in long distance EDFA cascaded 1 550 nm externally-modulated AM CATV. In this paper, composite second-order distortion (CSO) performance due to external phase modulation is studied theoretically. First, the external-PM and the self phase modulation (SPM) induced CSO is obtained analytically by solving the Schr-dinger equation with a perturbation method. Numerical results are then presented and discussed. According to the study, the CSO performance can be improved significantly by applying a suitable phase modulation index for any long distance AM-CATV. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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Connectivity of Power-Controlled Wireless Sensor Network with Linear Topology SUN Yan;CHEN Jian;CHEN Hui-min;JIN Yan-liang Journal of Shanghai University（Natural Science Edition）    2008, 14 (1): 15-18.   Abstract （2323）            Knowledge map    Save Due to energy limitation, wireless sensor networks are limited in life span. Therefore power consumption control has been a hot topic. In belt-shaped topology, relay nodes close to the sink must forward more data than those far from the sink. They inevitably consume more energy, therefore are exhausted quickly and become a bottleneck of the network. This paper aims to improve a radio range adjustment algorithm to increase lifespan of the bottlenecked nodes by ensuring network connectivity for uplink traffic and acceptance for downlink traffic. Related Articles | Metrics | Comments（0） Cited: Baidu(2)

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Cluster Preprocessing on Ontic Kernel and Histogram XIA Jiao-xiong;XU Jun;WU Geng-feng Journal of Shanghai University（Natural Science Edition）    2008, 14 (1): 19-25.   Abstract （2294）            Knowledge map    Save According to the connective characteristic of data and demands within data space, the principle of ontology is introduced into the process of cluster analysis. The pinpoint existence modality and dynamic distribution of data are described on the definition of ontic kernel and object data. Interrelation among the data can be studied with weak ontic kernel and strong ontic kernel. The cluster analysis histogram is constructed on the time of object data and different value on the same time. For different histogram statement, the algorithm that can process the limited gate value with rational function of controlling cluster is presented to determine the ultimate generic cluster. An application illustration is used to demonstrate feasibility and validity of the cluster preprocessing on ontic kernel and histogram (CPOKH).  Related Articles | Metrics | Comments（0） Cited: Baidu(5)

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Underground Pipeline Detection Based on Angular Sensing JIN Hong-ri;SHEN Lin-yong;ZHANG Ya-nan;QIAN Jin-wu Journal of Shanghai University（Natural Science Edition）    2008, 14 (1): 26-30.   Abstract （2049）            Knowledge map    Save A system for detecting the 3D shape of underground pipelines, especially in trenchless construction process, has been developed. This pipeline detecting system is composed of a gravity accelerometer, a magnetometer, a distance measuring mechanism and a control circuit. Driven in the pipe, the sensors measure the direction angle and distance at certain points. The 3D coordinates and the shape of the pipe are then obtained. Measurement repetitiveness of the pipe position is within ±5%. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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An Algorithm for Analyzing Magnetic Field Distribution of Saddle Excitation Coils in EM Flowmeter Sensor ZHAO Chen;LI Bin;CHEN Wen-jian; Journal of Shanghai University（Natural Science Edition）    2008, 14 (1): 31-35.   Abstract （2620）            Knowledge map    Save This paper studies rectangular saddle excitation coil widely used in industrial sensors for electromagnetic flowmeters. An analytic algorithm is introduced to simulate the magnetic field distribution of plane coils inside pipes. An approximate folded line method is proposed to simulate the field of saddle coils. Experiments show that the folded line method is simple and feasible. Related Articles | Metrics | Comments（0） Cited: Baidu(9)

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A MatrixPadé Approximation with Chosen Coefficients GU Chuan-qing;WANG Feng Journal of Shanghai University（Natural Science Edition）    2008, 14 (1): 36-39.   Abstract （2245）            Knowledge map    Save In terms of the recursive relation in the Lagrange polynomial form, a method of Lagrange-type matrix rational interpolation is presented in the inner product space. When all interpolation points approach zero, a matrix Pad é approximation with chosen coefficients is constructed, whose coefficients can be obtained by the least square method. An error formula of the matrix Padé approximation is given. Related Articles | Metrics | Comments（0）

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Existence of Positive Periodic Solution for a Delay Leslie-Predator-Prey Sys tem with Impulsive Effect LIANG Zhi-qing;ZHAO Qiang;ZHOU Sheng-fan; Journal of Shanghai University（Natural Science Edition）    2008, 14 (1): 40-45.   Abstract （2209）            Knowledge map    Save By using a continuation theorem based on coincidence degree theory, we study the existence of positive periodic solution for a delayed nonautonomous Leslie predator-prey system with impulsive effect. Sufficient conditions are obtained for the existence of positive periodic solution.  Related Articles | Metrics | Comments（0）

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Solution and Positive Solution to Nonlinear Equation for Elastic Beam with Both Ends Fixed YAO Qing-liu Journal of Shanghai University（Natural Science Edition）    2008, 14 (1): 46-51.   Abstract （2379）            Knowledge map    Save The existence of solution and positive solution is considered for a fourthorder nonlinear elastic beam equation with derivatives of all orders. In material mechanics, the equation describes deformation of an elastic beam whose two ends are fixed. The first, second and third derivatives express corner, bending moment and shearing stress of the beam, respectively. By choosing suitable equivalent norm in the Banach space -C 3［0,1］ and applying the Leray-Schauder fixed point theorem, several existence results are obtained for the equation. The results show that the equation has at least one solution or positive solution provided the “maximal height” of nonlinear term is appropriate on a bounded set of its domain. Related Articles | Metrics | Comments（0）

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Periodic Points and Symbolic Analysis for Some Low-Dimensional -Linear Torus Maps CHEN Hao-jun;CHEN Fang-yue;FU Xin-chu Journal of Shanghai University（Natural Science Edition）    2008, 14 (1): 52-57.   Abstract （2188）            Knowledge map    Save In this paper, periodic points of a class of maps on the 2-torus and the dynamics of a class of linear maps on the 3-torus are discussed. Using codes underlying the map operations, symbolic descriptions of the dynamics and admissibility conditions for itineraries are given for these discontinuous maps. Related Articles | Metrics | Comments（0）

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Dual Quermassintegrals of Harmonic Radial Combinations PAN Dong-yun;YUAN Jun;LENG Gang-song Journal of Shanghai University（Natural Science Edition）    2008, 14 (1): 58-60.   Abstract （2295）            Knowledge map    Save We establish the BrunnMinkowski inequality for the dual quermassintegrals of harmonic radial combinations of star bodies, and prove its equivalence properties to the Minkowski inequality for Lp-dual mixed quermassintegrals. Related Articles | Metrics | Comments（0）

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A Numerical Method for Optimal Investment and Consumption with Transaction Costs MA Kun;ZHU Zheng-you Journal of Shanghai University（Natural Science Edition）    2008, 14 (1): 61-64.   Abstract （1981）            Knowledge map    Save An optimal consumption and investment policy with transaction costs is discussed in this paper. After the HJB equation of this problem and the variational inequality are obtained, the equivalent free boundary problem is proposed, and a numerical method for solving the problem established. The new methods can reduce workload compared to a former method. Related Articles | Metrics | Comments（0）

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Optimal Dividend Paying Strategy and Optimal Asset Allocation for Insurance Companies and the Numerical Solution TU Hong;ZHU Zheng-you Journal of Shanghai University（Natural Science Edition）    2008, 14 (1): 65-59.   Abstract （2369）            Knowledge map    Save The optimal dividend paying strategy and optimal asset allocation for insurance companies are studied in this paper. The wealth process is modeled as a portfolio combining a risky asset and a riskless asset as well as a stochastic claim process. The corresponding HJB equation for this problem is derived. Based on a qualitative analysis of the solution, the numerical solution to the equation is obtained. The optimal asset allocation between a risky asset and a riskless asset and the optimal dividend paying strategy are derived. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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Electron Tunneling Effect in the Wall of Cytoskeletal Microtubule HU Jian;QIU Xi-jun Journal of Shanghai University（Natural Science Edition）    2008, 14 (1): 70-73.   Abstract （2245）            Knowledge map    Save We treat protofilaments in the wall of microtubule (MT) as a onedimensional dynamic system based on symmetry of the cytoskeletal MT structure. Using a double-potential-well model and quantum mechanics, we calculate the electron penetration probability through potential barrier and ground state level splitting induced by the electron tunneling effect, which occurs in a protofilament in the MT wall. Some interesting results are obtained.  Related Articles | Metrics | Comments（0） Cited: Baidu(2)

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Internal Quantum Efficiencies of Flat-Band Solar Cells YANG Wen-ji;MA Zhong-quan;TANG Xing;ZHAO Wen-gang;XU Fei;WANG De-ming;ZHAO Zhan-xia Journal of Shanghai University（Natural Science Edition）    2008, 14 (1): 74-79.   Abstract （2801）            Knowledge map    Save The total internal quantum efficiency (IQE) of a flat-band p-n homo-junction solar cell is calculated, and contributions of the separate parts analyzed. It has been found that both the cell part widths and the surface recombination velocities have significant influence on the IQEs. With mathematical transformation and approximation, the differential equation of the minority carrier density in a textured cell takes the same form as the flat cell. What makes differences is that texturization slightly enhances the IQEs for photons with longer wave lengths while notably increasing external quantum efficiency. Therefore it is important for the solar cell’s good performance. The results are of technical importance in designing solar cells and their surface structures. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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Asymmetrical Synthesis of Optical Active Amines WANG Xin;PU Jia-qi Journal of Shanghai University（Natural Science Edition）    2008, 14 (1): 80-84.   Abstract （2439）            Knowledge map    Save Optical active amines 4a-d were prepared in three steps from prochiral ketones 1a-d using R- or S-α-phenylethylamine as chiral source. All reactions were carried out under atmospheric pressure, and expensive chemicals were not used. Medium or good stereoselectivities were found. Over all yields were 39%～50%. Reaction time of imination plays an important role for E/Z selectivity of product 2a-d. Stereoselectivity would be improved if much lower temperature were used in the reduction. Related Articles | Metrics | Comments（0）

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FEM Analysis of 3D Temperature Field in Connection Aisle between Tunnels Constructed Using Artificial Freezing Method JIN Wei-wei;CHEN You-liang;LI Lei;WANG Ling-min Journal of Shanghai University（Natural Science Edition）    2008, 14 (1): 85-90.   Abstract （2291）            Knowledge map    Save Artificial freezing method is an economical and effective method for digging connection aisles between tunnels. During the freezing, whether or not the wall reaches the designed thickness is important for safe construction. In this paper, the temperature field in the connection aisle of Shanghai East-Fuxing Road tunnels is computed using 3D FEM. The inclined installation of freezing tubes is taken into account in the computation. Paths are established in the bottom, middle and top of the freezing wall for single and double rows of the freezing tubes. Temperature distribution curves are plotted for each path. Significant conclusions can be drawn through observation of the patterns of freezing wall thickness changing with time. The results are useful for safe construction of tunnel connection aisles. Related Articles | Metrics | Comments（0） Cited: Baidu(14)

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Preparation of Aqueous Polyurethane by Non－solvent Process HU He－feng;XUE Liang;SHI Ai－hua;GONG De－chang Journal of Shanghai University（Natural Science Edition）    2008, 14 (1): 91-95.   Abstract （2293）            Knowledge map    Save The dispersive and stable aqueous polyurethane emulsion was prepared by IPDI, DMPA, poly (propylene glycol) as raw material and EA as chain extender without solvent. The production was characterized by FTIR and granulometer. The influence of the ratio between soft and hard chain segments and the content of PPG adding into the soft chain segment on mechanical and waterproof property of film were investigated. The influence of content of hydrophilic group on waterproof property was also investigated. The results show that flexibility and waterproof characteristic of film are improved with increasing content of the soft chain, and mechanical strength and waterproof property of the film are improved with increasing content of PE added to soft chain. Related Articles | Metrics | Comments（0）

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Characterization of Interaction between Salvianolic Acid B and Phages Using Capillary Electrophoresis LIU Shu-peng;SUN Ye;GUO Wei;XU Yu-hong Journal of Shanghai University（Natural Science Edition）    2008, 14 (1): 96-99.   Abstract （2132）            Knowledge map    Save Binding activity between Salvianolic acid B and selected phages from affinity biopanning in phage display library were studied with capillary lectrophoresis based on the Hummel-Dreyer methods. The binding constant was calculated with Scatchard analysis using PRISM software. The results indicate that the surface proteins expressed by the phage clone interact specifically with Salvianolic acid B, and it is feasible to determine the binding constant between the selected phage and Salvianolic acid B using CE. Related Articles | Metrics | Comments（0） Cited: Baidu(2)

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Volatile Flavor Compounds of Tofu QI Shun-ping;WENG Xin-chu Journal of Shanghai University（Natural Science Edition）    2008, 14 (1): 100-105.   Abstract （2195）            Knowledge map    Save Volatile flavor components of tofu were analyzed by simultaneous distillation-extraction (SDE) combined with gas chromatographymass spectrometry (GC-MS). A total of 44 compounds were identified, including 12 alcohols, 12 aldehydes, 10 esters, 2 ketones and 8 other compounds. The odor activity values (OAV) of the compounds showed that (E,E)-2,4-decadienal, dimethyl disulphide, 3-methylbutanal, ethyl butyrate, and 2-methylbutanal contributed to the characteristic odor of tofu which contained sweet, abbage, fruity and cocoa aroma. Related Articles | Metrics | Comments（0） Cited: Baidu(5)

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Application of Significance Analysis of Microarrays in Analyzing Feature of Burkitt Lymphoma Staging GAO Shan;ZHANG Hong;YIN Jing-yuan Journal of Shanghai University（Natural Science Edition）    2008, 14 (1): 106-110.   Abstract （2275）            Knowledge map    Save Based on a set of gene expression data of Burkitt lymphoma, the method of significance analysis of microarrays (SAM) was used to select a group of 90 feature genes significantly related with AnnArbor staging of Burkitt lymphoma. Nine genes have been found most frequently appear in involved pathways of those 90 feature genes, falling into the Gene Ontology (GO) category of signal transduction and having common functions related with mechanisms of tumor origin or development. In those functions, two functions related with worse development of Burkitt lymphoma were first reported. Related Articles | Metrics | Comments（0） Cited: Baidu(19)

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Histogram-Based Analysis against Model-Based Steganography SUN Wen-yong;ZHANG Xin-peng;WANG Shuo-zhong Journal of Shanghai University（Natural Science Edition）    2008, 14 (2): 111-115.   Abstract （2231）            Knowledge map    Save Model-based (MB) steganography for JPEG images can keep the histogram of DCT coefficients almost unchanged, therefore can resist the previous steganalytic methods. However, a loophole still exists. In MB steganography, a model derived from the original histogram is used so that the distribution of DCT coefficients in a smooth area becomes similar to that in a texture area. In view of this, we propose a steganalytic scheme against the MB steganography, which examines difference between DCT coefficient histogram in texture blocks and that of the whole image, and compare this difference with a threshold. Experimental results show that the proposed method can effectively detect the presence of secret data in an image embedded with the MB steganography. Related Articles | Metrics | Comments（0） Cited: Baidu(12)

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A Delay-Constrained Multicast Routing Algorithm Based on Edge Selection Function WANG Xin-mei;ZHU Min;ZOU Jun-ni;WANG Min Journal of Shanghai University（Natural Science Edition）    2008, 14 (2): 116-120.   Abstract （2290）            Knowledge map    Save Based on the analysis of the algorithm for routing multicast with the constraint of QoS using the edge selection function, the paper discusses the construction of multicast tree when any change occurs in the destination or network cost. From the practical requirements, a new algorithm is proposed for selecting the edge that considers destination cost and network cost simultaneously. The algorithm provides a new method for link selection, improves the node search, and optimizes the destination and network cost. Simulation results are given, indicating that the cost and average delay of the proposed algorithm are better than destination-driven shortest path(DDSP).  Related Articles | Metrics | Comments（0） Cited: Baidu(4)

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A Fused-Tapered Temperature Sensor with Long Coupling Region XIANG Xiao-ting;YAO Shou-quan Journal of Shanghai University（Natural Science Edition）    2008, 14 (2): 121-124.   Abstract （2252）            Knowledge map    Save Optic-fiber temperature sensor is an instrument required in high voltage environment. We make the optical coupler more sensitive to temperature by elongating the couple length. Therefore, it can be used to measure temperature. It has good reliability and repeatability since no additional materials are used. This research investigates linearity and sensitivity of couplers with different coupler length. R of the present example in the experiment has reach 0.7% per degree Celsius when the temperature ranges from -40 ℃ to 90 ℃, and it has good linearity and repeatability. Related Articles | Metrics | Comments（0） Cited: Baidu(2)

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Watermarking Algorithm for Embedding MIDI Information into Digital Music Score CHEN Gen-fang;ZHANG Wen-jun Journal of Shanghai University（Natural Science Edition）    2008, 14 (2): 125-129.   Abstract （2328）            Knowledge map    Save A blind watermarking algorithm for embedding MIDI (Musical Instrument Digital Interface) information into a binary image of music score based on the optical music recognition (OMR) is presented. Both the information of digital music score and MIDI can be reconstructed. Experiment results show that the embedded watermark has no effect on the precision of music score recognition. It is useful in integrity auditing and synchronized transmission of digital music score together with the MIDI information. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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Phase and Amplitude Control Strategy for Three-Phase PWM Converters WU Guo-xiang;CHEN Guo-cheng;LI Jie;MA Yi-wei;WANG De-li;YU Jun-jie; Journal of Shanghai University（Natural Science Edition）    2008, 14 (2): 130-135.   Abstract （2182）            Knowledge map    Save A three-phase PWM rectifier controlled by phase and amplitude is presented. The lagging phase angle θ between supply voltage and input voltage of rectifier and modulation are controlled with realtime detection of power factor angle and DC bus voltage. The algorithm is linearized, and decoupling control is implemeted to achieve unity power factor. The range of parameters, constraint conditions, and adjustment process of system are analyzed under load disturbance. Harmonic of the threephase PWM rectifier is also analyzed. The control algorithm is simple, and easy to implement, and verified by experiments. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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Application of EZ-COMPASS-3 in 3D Trenchless Detection of Underground Pipeline LI Jun-yao;ZHANG Ya-nan;SHEN Lin-yong;QIAN Jin-wu Journal of Shanghai University（Natural Science Edition）    2008, 14 (2): 136-141.   Abstract （2251）            Knowledge map    Save For underground pipeline trenchless detection, a new method is proposed that employs EZ-COMPASS-3 to detect the anglular information of discrete points on the pipeline, and reconstruct the spatial trajectory of the pipeline with a newly developed reconstruction algorithm. EZ-COMPASS-3 is a kind of electronic compass, consisting of a 3-dimensional magnetometer and two tilt compensated sensors. Hard iron compensation and tilt compensation should be included to enhance measure accuracy. The corresponding compensation theory is described. Theoretical analysis and testing of the errors show effectiveness of the proposed method. Related Articles | Metrics | Comments（0） Cited: Baidu(6)

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Computation for Transition Matrix and VaR in CreditMetrics Model WANG Wen-yuan;XIE Xiao-heng;HE You-hua Journal of Shanghai University（Natural Science Edition）    2008, 14 (2): 142-147.   Abstract （5201）            Knowledge map    Save The CreditMetrics model is a quantified credit risk management model. The determination of credit transition probability matrix is a key problem for this model. This paper presents a method validated by stochastic simulation for estimating credit transition probability matrix, and determines appropriate sample size by error analysis. It improves the loan cash flow calculation in the original model that is all possible transition situations within n years for a given type of loan customers to be considered for the load cash flow conversion. Finally we calculate the loan value at risk (VaR) with a kernel estimate method, and compare with that of the original model. The result shows the effectiveness of our method. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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p-Polar Curvature Images of Star Bodies and p-Affine Surface Areas LU Song-jun;LENG Gang-song Journal of Shanghai University（Natural Science Edition）    2008, 14 (2): 148-151.   Abstract （2359）            Knowledge map    Save This paper introduces the concept of p-polar curvature images of star bodies and establish the p-polar curvature image inequality, and proves the bound for the product of p-affine surface areas of the p-polar curvature images of star bodies and their polar bodies. As an application of p-polar curvature image, we demonstrate the extended p-Minkowski inequality for mixed p-affine surface areas of convex bodies. Related Articles | Metrics | Comments（0） Cited: Baidu(2)

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Limit Solutions to Modified KdV Equation OU Mei-ying;XUAN Qi-fei;ZHANG Da-jun Journal of Shanghai University（Natural Science Edition）    2008, 14 (2): 152-155.   Abstract （2425）            Knowledge map    Save This paper describes an exact limit procedure by which a simple formula for the N-doublepole solution to the modified KdV equation is derived from its 2N-soliton solution in the Hirota’s form. This procedure is general and can be applied to other nonlinear evolution equations with multi-soliton solutions in the Hirota's form.  Related Articles | Metrics | Comments（0）

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An Iterative Method for Solving Linear Ill-Posed Problems Based on Dynamical Systems SUN Jing;HE Guo-qiang Journal of Shanghai University（Natural Science Edition）    2008, 14 (2): 156-160.   Abstract （1931）            Knowledge map    Save This paper proposes an iterative method for solving illposed operator equations based on dynamical systems and discuss the convergence properties and convergence rates of the method. Numerical examples are given, which is in agreement with the theoretical results. Related Articles | Metrics | Comments（0）

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Numerical Simulation of Rayleigh Breakup in LowVelocity Liquid Jet Journal of Shanghai University（Natural Science Edition）    2008, 14 (2): 161-167.   Abstract （2805）            Knowledge map    Save Dynamic breakup of a Newtonian axisymmetric liquid jet injected into another immiscible Newtonian liquid was investigated. The full transient process from jet start-up to breakup into drops was simulated numerically by solving the timedependent axisymmetric equations of motion and continuity using an algorithm based on the finite volume method and the volume of fluid (VOF) method. In the present work, the physics was captured about the jet breakup and drop formation, the relation was given between jet core length and Weber number and velocity and pressure distributions was also obtained. Related Articles | Metrics | Comments（0）

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Relation between Thermal Deformation of Shadow Mask and the Slot Size GAO Peng;ZHU Wei-ping Journal of Shanghai University（Natural Science Edition）    2008, 14 (2): 168-172.   Abstract （2320）            Knowledge map    Save Shadow mask, an electron sieve mounted in the front of CRT in color TV, is inevitably heated by the captured electrons. Thermal deformation leads to deflection of electron beams, which will spoil color purity. This paper discusses the relation between the thermal deformation of a shadow mask and its slot size, and predict the beamlanding shift. An improved equivalent structural elastic modulus with orthogonal anisotropy is proposed to construct the finite element model for the mask. The equivalence requires that the same bending stiffness across both slot and bridge are the same, and the extensional stiffness between the model and the prototype are also the same. This paper takes a large number of different representative units from the entire shadow mask according to the local geometries and erosion features of the slots to localize the equivalent elastic modulus in our model. In addition, this paper takes advantage of asymptotic method to confirm the effects of the modulus on deformation. Simulation results agree with the practice, which can be used to guide the mask design. Related Articles | Metrics | Comments（0）

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Simulation of Air Launched Missile Based on Moving Chimera Grid WANG Zheng-yu;LI Xiao-wei Journal of Shanghai University（Natural Science Edition）    2008, 14 (2): 173-176.   Abstract （2280）            Knowledge map    Save This paper simulates the process of an airlaunched missile traversing across a shockwave, using a dualtime method based on a motive chimera grids and the K-ω turbulent model. By studying a simple 2D model, the results provide useful reference for understanding interference between the moving missile and the shockware, which may directly affect the velocity and trajectory of the missile. Related Articles | Metrics | Comments（0） Cited: Baidu(3)

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Improvement of Wave-front Aberration Theory of Grating WANG Juan;LU Li-jun Journal of Shanghai University（Natural Science Edition）    2008, 14 (2): 177-182.   Abstract （2373）            Knowledge map    Save Based on Chrisp's wave-front aberration theory of grating, the wave-front aberration coefficients are derived with a grating surface of polynomial expression, which can be used to design and analyze a grating of toroidal or conicoid surface figure. The transformation formula can be obtained from the wavefront aberration to transverse aberration on image plane even if the exit wave front is astigmatic and the image plane is out of focus. Finally, the numerical results are compared with the ray tracing results. Related Articles | Metrics | Comments（0） Cited: Baidu(3)

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Synthesis of Fe3O4/PAM Core-Shell Magnetic Particles by EB-Irradiation LIU Xin-wen;ZU Jian-hua;BAO Bo-rong;WU Ming-hong;TONG Long;SUN Gui-sheng Journal of Shanghai University（Natural Science Edition）    2008, 14 (2): 183-186.   Abstract （2293）            Knowledge map    Save Magnetic nanoparticles were perpared by the chemical coprecipitation of ferrouschloride and ferricchloride. Fe3O4/PAM core-shell composite magnetic particles were synthesized by EBirradiation and characterized by XRD, AFM, and FTIR. The results indicate that the only product prepared by co-operation method was singlephase Fe3O4 and its diameter was about 8 nm. The microsphere was spherical and its diameter was about 100 nm. It has been found that the diameter of the core-shell microparticles can be controlled by changing concentration of monomer AM, magnetic nanoparticles Fe3O4 and doses of irradiation. Related Articles | Metrics | Comments（0）

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Development of Up-to-Date MnZn Ferrite Material with Low Power Loss and High Bs LI Gang;GONG Xiao-yan;SHEN Jian-gang Journal of Shanghai University（Natural Science Edition）    2008, 14 (2): 187-189.   Abstract （2372）            Knowledge map    Save MnZn ferrite with low power loss and high Bs at high operating temperature has been prepared by choosing highly pure raw materials, using conventional ceramic process，and adding optimum contents of CaCO3, TiO2, Nb2O5, and V2O5. According to the solid-phase reaction mechanism of ferrite，optimum sintering process and matched atmosphere were used to prepare high quality MnZn ferrite material. High density, high Tc and high Bs were achieved. Related Articles | Metrics | Comments（0）

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Extraction of Lanthanum with 8-Hydroxyquinoline ZHANG Qian;BAO Bo-rong Journal of Shanghai University（Natural Science Edition）    2008, 14 (2): 190-193.   Abstract （1979）            Knowledge map    Save The solvent extraction of La3+ from hydrochloric acid solutions was Investigated using 8-Hydroxyquinoline as extractant. The effect of equilibrium of aqueous acidity on extraction of La3+ using 8Hydroxyquinoline was discussed. The effects of extractant concentraction, different diluents and chloride ion on extraction reaction were also studied. With a doublelogarithmic slope method, composition of the extracted species of 8-Hydroxyquinoline was derived. Related Articles | Metrics | Comments（0） Cited: Baidu(5)

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Effect of Heat Treatments on Corrosion and Hydrogen Uptake Behaviors in N36 Zirconium Alloy LU Yan-ping;YAO Mei-yi;ZHOU Bang-xin Journal of Shanghai University（Natural Science Edition）    2008, 14 (2): 194-199.   Abstract （2450）            Knowledge map    Save N36 zirconium alloy specimens were treated in different ways at 1 020 °C/20 min WQ + C.R. (cold rolling) + 580 °C/50 h AC， 820 °C/2 h AC+580 °C/50 h AC, 820 °C/2 h AC+C.R.+580 °C/50 h AC, and 700 °C/4 h AC+C.R.+580 °C/50 h AC, respectively. Their microstructures were examined by transmission electron microscopy (TEM). The corrosion and hydrogen uptake behaviors of these specimens were investigated after autoclave tests in superheated steam at 400 °C/10.3 MPa. Results show that the corrosion resistance of the specimen treated at 1 020 °C/20 min WQ+C.R. (cold rolling)+580 °C/50 h AC is the best among them. The reason is that such treatment makes the second phase particles fine and dispersed in αZr matrix. The corrosion resistance of the specimen treated at 820 °C/2 h AC+580 °C/50 h AC was the worst due to the presence of coarse second phase particles. The corrosion resistance of these specimens treated at 820 °C/2 h AC+C.R.+580 °C/50 h AC and 〖JP2〗700 °C/4 h AC+C.R.+580 °C/50 h AC is in between. Heat treatments have less influence on hydrogen uptake of N36 than that of Zr4. This may be the reason that the second phase particles in N36 alloy is less reactive with hydrogen than that of Zr(Fe,Cr)2 SPPs in Zr4. Related Articles | Metrics | Comments（0） Cited: Baidu(4)

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