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Determination of ocean tide loading displacements in Hong Kong using GPS technique

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Science China Earth Sciences 2010年第7期53卷 993-1007页

作者： YUAN LinGuo1,3. DING XiaoLi1, SUN HePing2, ZHONG Ping1,3.& CHEN Wu1 1 department of Land Surveying and Geo-Informatics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China 2 Key Laboratory of Dynamic Geodesy, Institute of Geodesy and Geophysics, Chinese Academy of Sciences, Wuhan 43.077, China 3.department of Surveying engineering, School of Civil engineering, Southwest Jiaotong University, Chengdu 61003., China 1. department of Land Surveying and Geo-Informatics The Hong Kong Polytechnic University Kowloon Hong Kong China3. Department of Surveying Engineering School of Civil Engineering Southwest Jiaotong University Chengdu 610031 China2. Key Laboratory of Dynamic Geodesy Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan 430077 China

Ocean tide loading (OTL) displacements of eight principal constituents at 12 sites in Hong Kong were determined using more than eight years of continuous GPS observations. Parameters of the OTL displacements were estimated using daily GPS solutions obtained with precise point positioning (PPP) technique. The results were compared with predictions from seven latest global ocean tide models. Gravity measurements of OTL in Hong Kong were also used to validate the GPS results. The study shows that the results from both the GPS and gravity measurements agree best with the GOT4.7 and NAO99b models, when the K1 and K2 constituents are excluded. The agreements between the GPS and the model estimates are generally at sub-millimeter level in both the horizontal and vertical directions, except for S2, K2 and K1 constituents that have relatively larger errors. After removing the systematic biases between the GPS and the model estimates, the misfits of M2, S2, N2, O1, P1 and Q1 at all sites are within 0.5 and 1.0 mm in the horizontal and the vertical directions, respectively, whereas K1 and K2 show relatively larger misfits of up to 2.3.mm. Both the GPS and the gravity S2 estimates have large biases with unknown reasons when compared with the modeled values, which needs to be further investigated. The study demonstrates that GPS is capable of estimating the OTL displacements with the same accuracy as the model predictions, especially for coastal areas.

关键词： GPS ocean tide loading ocean tide model site displacement

Sol-gel preparation and spectroscopic study of the pyrophanite MnTiO_3.nanoparticles

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Science China Chemistry 2005年第3期48卷 210-215页

作者： ZHOU Guowei1, KANG Youngsoo2, LI Tianduo1 & XU Guiying3.1. School of Light Chemicals and Environmental engineering, Shandong Institute of Light Industry, Jinan 250100, China 2. department of Chemistry, Pukyong National University, Daeyeon-3.dong, Nam-gu, Pusan 608-73., Korea 3. Key Laboratory for Colloid and Interface of Ministry of Education of China, Shandong University, Jinan 250100, China 1. School of Light Chemicals and Environmental engineering Shandong Institute of Light Industry 250100 Jinan China 2. department of Chemistry Pukyong National University Daeyeon-3-dong Nam-gu 608-737 Pusan Korea 3. Key Laboratory for Colloid and Interface of Ministry of Education of China Shandong University 250100 Jinan China

The nanosized xerogel of titanium dioxide (TiO2) and manganese oxides (MnO2, Mn2O3. Mn3.4) was prepared by the sol-gel method using manganese chloride (MnCl2·4H2O) and titanium isopropoxide (Ti(O-iPr)4) as precursors in cetyltrimethylammonium bromide (CTAB)/ ethanol/H2O/HCl micelle solutions, following the calcinations of the produced powders at differ-ence temperatures. The nanostructure and phase composition of these nanoparticles were characterized with X-ray powder diffraction (XRD), transmission electron microscopy (TEM), en-ergy dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). The spectroscopic characterizations of these nanoparticles were also done with UV-Vis spectroscopy and laser Raman spectroscopy (LRS). XRD patterns show that the pyrophanite MnTiO3.phase was formed at the calcinations temperature of 900℃. The TEM images show that the nanoparti-cles are almost spherical or slight ellipose and the sizes are 50 nm on average. The UV-Vis spectra show that the nanosized MnTiO3.have significant absorption bands in the visible region. There are new absorption peaks of MnTiO3.nanoparticles in LRS compared with the pure TiO2 powder.

关键词： pyrophanite MnTiO3. nanoparticles, spectroscopy, CTAB micelle, sol-gel.

A MESSAGE-DRIVING FORMALISM FOR MODELING AND SIMULATION OF MULTI-AGENT SUPPLY CHAIN SYSTEMS

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Journal of Systems Science and Systems engineering 2011年第4期20卷 385-399页

作者： Wenzhe TAN1 Yueting CHAI2 Yi LIU3.1department of Automation, Tsinghua University, Beijing, 100084, China 2department of Automation, Tsinghua University, Beijing, 100084, China 3.0} of Automation, Tsinghua University, Beijing, 100084, China department of Automation Tsinghua University Beijing China

To acquire a competitive advantage in the expanding market, manufacturing enterprises should be able to manage their supply chains as effectively as possible. It is now becoming popular to model supply chains as multi-agent systems and use discrete event simulation to learn more about their behaviors or investigate the implications of alternative configurations. In order to enhance the computational efficiency and keep the simulation credibility, this paper proposes a message-driving formalism for the simulation of multi-agent supply chain systems. Through the message-driving formalism, the problem of shared variables is addressed and the parallel operation of agents is implemented. Simulation experiments with a prototype implementation show that the message-driving formalism is able to provide credible results in significantly less simulation time.

关键词： Supply chain multi-agent system modeling and simulation parallel discrete event simulation message-driving formalism

Effect of specimen thickness on Mode Ⅱ fracture toughness of rock

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Journal of Central South University of Technology 2001年第2期8卷 114-119页

作者： RAO Qiu hua 1,SUN Zong qi 1,WANG Gui yao 2,XU Ji cheng 3.ZHANG Jing yi 3.(1.College of Resources, Environment and Civil engineering, Central South University, Changsha 410083. China 2.River and Sea department, Changsha Communications Univer College of Resources Environment and Civil Engineering Central South University Changsha China River and Sea department Changsha Communications University Changsha China Open Lab of Mechanics Central South University Changsha China

Anti symmetric four point bending specimens with different thickness, without and with guiding grooves, were used to conduct Mode Ⅱ fracture test and study the effect of specimen thickness on Mode Ⅱ fracture toughness of rock. Numerical calculations show that the occurrence of Mode Ⅱ fracture in the specimens without guiding grooves (when the inner and outer loading points are moved close to the notch plane) and with guiding grooves is attributed to a favorable stress condition created for Mode Ⅱ fracture, i.e. tensile stress at the notch tip is depressed to be lower than the tensile strength or to be compressive stress, and the ratio of shear stress to tensile stress at notch tip is very high. The measured value of Mode Ⅱ fracture toughness K ⅡC decreases with the increase of the specimen thickness or the net thickness of specimen. This is because a thick specimen promotes a plane strain state and thus results in a relatively small fracture toughness.

关键词： Mode Ⅱ fracture toughness rock fracture stress analysis specimen thickness

Parameter identification theory of a complex model based on global optimization method

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Science China(Physics,Mechanics & Astronomy) 2008年第11期51卷 1722-1732页

作者： QU Jie1, JIN QuanLin2 & XU BingYe3.1 College of Automotive engineering, South China University of Technology, Guangzhou 510640, China 2 Beijing Research Institute of Mechanical and Electrical Technology, Beijing 100083. China 3.department of engineering Mechanics, Tsinghua University, Beijing 100084, China 1. College of Automotive engineering South China University of Technology Guangzhou 510640 China 2. Beijing Research Institute of Mechanical and Electrical Technology Beijing 100083 China 3. department of engineering Mechanics Tsinghua University Beijing 100084 China

With the development of computer technology and numerical simulation technology, computer aided engineering (CAE) technology has been widely applied to many fields. One of the main obstacles, which hinder the further application of CAE technology, is how to successfully identify the parameters of the selected model. An elementary framework for parameter identification of a complex model is provided in this paper. The framework includes the construction of objective function, the design of the optimization method and the evaluation of the identified results, etc. The parameter identification process is described in this framework, taking the parameter identification of the superplastic constitutive model considering grain growth for Ti-6Al-4V at 927°C as an example. The objective function is the weighted quadratic sums of the difference between the experimental and computational data for the stress-strain relationship and the grain growth relationship; the designed optimization method is a hybrid global optimization method, which is based on the feature of the objective function and incorporates the strengths of genetic algorithm (GA), the Levenberg-Marquardt algorithm and the augmented Gauss-Newton algorithm. The reliability evaluation of parameter identification result is made through the comparison between the calculated and experimental results and between the theoretical values of the parameters and the identified ones.

关键词： constitutive model parameter identification theory inverse analysis global optimization

Electronic structure and magnetism of R(Fe,Si)_(12) (R=Y,Nd)

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Science China(Physics,Mechanics & Astronomy) 2006年第2期49卷 195-202页

作者： SUN Guang’ai1, CHEN Bo1, DU Honglin2, FAN Zhijian1, GAO Tao3.& QI Xinhua3.. Institute of Nuclear Physics and Chemistry, China Academy of engineering Physics, Mianyang 621900, China 2. department of physics, Peking university, Beijing 100871, China 3. Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China 1. Institute of Nuclear Physics and Chemistry China Academy of Engineering Physics Mianyang 621900 China 2. department of physics Peking university Beijing 100871 China 3. Institute of Atomic and Molecular Physics Sichuan University Chengdu 610065 China

The newly developed full-potential linearized augmented plane wave (LAPW) and local orbitals (lo) based on standard APW methods are briefly introduced, and the structure and magnetic properties of R(Fe, Si)12 compounds (R = Y, Nd) are calculated using the method. The distribution of Si at different sites is analyzed based on total energy of one crystal unit with structure having been optimized. The characters of magnetic mo-ments, total density of states (TDOS) and partial density of states (PDOS) for different crystal sites Si occupies are obtained and analyzed. The results show that the total mag-netic moments of RFe10Si2 (R = Y, Nd) are larger than those of RFe10M2 (M = Ti, V, Cr, Mn, Mo and W) and the hybridization mechanism is seen as follows. Si(8j) reduce the mag-netic moments of Fe at three sites, however, Si(8f) mainly reduce the magnetic moments of Fe(8i) and Fe(8j) atoms. The Curie temperature is markedly enhanced by the introduc-tion of Si atoms according to spin fluctuation of DOS at Fermi level.

关键词： (L)APW+lo method R(Fe Si)12(R = Y Nd) magnetic moment Density of state.

Laser Ablated Superconducting and Related Thin Films:A Microscopical Investigation

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Rare Metals 1993年第4期12卷 271-274页

作者：沙维 department of Materials Imperial CollegePrince Consort RoadLondon SW7 2BPEngland

Laser ablated high temperature superconducting and related thin films are investigated with a microscopical point of *** microstructure and microchemistry of three thin films(Y-Ba-Cu-O, Bi-Pb-Sr-Ca-Cu-O and Sr-Ca-Cu-O... 详细信息

关键词： Laser ablation Superconducting thin film Microscopy

Seamlet carving for shape-aware image resizing

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Science China(Information Sciences) 2012年第5期55卷 1073-1081页

作者： LIN Xiao 1,2,SHENG Bin 1,MA LiZhuang 1,SHEN Yang 1 & CHEN ZhiHua 3.1 department of Computer Science and engineering,Shanghai Jiao Tong University,Shanghai 200240,China 2 Academy of Information Technology,Luoyang Normal University,Luoyang 471022,China 3.department of Computer Science and engineering,East China University of Science and Technology,Shanghai 20023.,China 1. department of Computer Science and engineering Shanghai Jiao Tong University Shanghai 200240 China2. Academy of Information Technology Luoyang Normal University Luoyang 471022 China3. Department of Computer Science and Engineering East China University of Science and Technology Shanghai 200237 China

In this paper we propose an optimized seam-carving approach for anti-shearing image *** image/video seam-carving strategy only focuses on deleting the pixels along 8-connected seams,which may lead to the obvious information loss during *** the traditional seam-carving methods,our approach can construct a seamlet to handle the discontinuous pixels and further achieve an optimized image resizing results with *** particular,to suppress zigzag artifacts,we introduce the anti-shearing energy into the seamlet generation,which includes two steps:1) the energy map is formalized by using Gabor filtering and the saliency map;2) The energy computation is optimized in Gabor feature space to obtain the resizing results without the connectivity *** experimental results and comparisons show the effectiveness of our method.

关键词： image resizing seamlet carving saliency map

Effect of Interface on Mechanical Property of Steel-mushy Al-20Sn Bonding Plate

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Journal of Wuhan University of Technology(Materials Science) 2006年第1期21卷 60-62页

作者：张鹏 department of Mechanical engineering Beijing Jiaotong University Beijing 100044 China

The ratio of Fe-Al compound at interace, which could determine the quarttity of Fe-Al compound at the interace of steel-mushy Al- 20 Sn bonding plate, was used to characterize the interfacial structure of steel-mushy Al-20 Sn bonding plate quantitatively. The effect of ratio of Fe-Al compound at interface on interacial shear strength was investigated perfectly. The results show that the relationship between ratio of Fe-Al compound at interace and interfacial shear strength is S = 3.3.＋ 1.91 t - 0.013.t^2 （ where t is ratio of Fe-Al compound at in- terface and S is interfacial shear strength ）. When the ratio of Fe-Al compound at interface is 71%, the largest interfacial shear strength 70.9 MPa is got. This reasonable ratio of Fe-Al compound at interface is a quarttitative criterion of interfacial embrittlement. When the ratio of Fe-Al compound at interface is higher than 71% , interfacial embrittlement will occur.

关键词： interfacial structure ratio of Fe-Al compound at interface interfacial shear strength