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On three-dimensional geological modeling and visualization

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Science china Earth Sciences 2004年第8期47卷 739-748页

作者： WU Qiang1 & XU Hua2.1. department of Resource Exploitation engineering,{2. University of Mining and technology, Beijing 100083,{2. 2. Beijing institute of Petrochemical technology, Beijing 102.17,{2. department of Resource Exploitation engineering China University of Mining and Technology Beijing China Beijing institute of Petrochemical technology Beijing China

The technology of 3D geological modeling will bring about great changes in the methods of geological data acquiring, storing, processing and displaying. However, no perfect or convenient software systems have been developed up to now since the geologic data which re-flect geological entities bear the feature of diversity, uncertainty and complexity. Some supervoxel models, mathematical models of fault and geometrical models of fold have been contrived so as to show the space geometric configuration of the complicated geologic structures. The application-oriented system architecture for 3D geological modeling is established; and a novel design concept based on spatial data processing is also proposed with the technology of solid modeling as its core and the application of models as its objective. Theories and methods for 3D geological modeling will hopefully be enriched and developed. In the light of these theories and methods, a feature-based navigation visualization technique is also put forward in the paper. By integrating geo-database, graphics libraries and KBS with 3D dynamic simulation systems, geologists will be able to capture the partial characteristics and whole structure embodied in the geological data in a direct-viewing, figurative and accurate manner.

关键词： 3D geological modeling,geometrical model,system architecture,visualization

A new sequential learning algorithm for RBF neural networks

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Science china(Technological Sciences) 2004年第4期47卷 447-460页

作者： YANG Ge1, LV Jianhong1 & LIU Zhiyuan2.1. department of Power engineering, Southeast University, Nanjing 2.0096,{2. 2. department of Power engineering, Nanjing institute of technology, Nanjing 2.0013,{2. department of Power engineering Southeast University Nanjing China department of Power engineering Nanjing Institute of Technology Nanjing China

Due to their inherent imperfections, it is hard to use the static neural networks for nonlinear time-varying process modeling and prediction, and the minimal resource allocation network (MRAN) is difficult to be realized for its too many regulation parameters. A new sequential learning algorithm for radial basis function (RBF) neural networks based on local projection named Local Projection Network (LPN) is proposed in this paper. The results of validation for several benchmark problems with the new algorithm show that the presented LPN not only has the same level as M-RAN in network size and precision of the outputs, but also has fewer regulation parameters and is more predictable.

关键词： radial basis functions, local projection network, minimal resource allocation network, learning algorithm.

Theoretical calculation of the finishing rolling impact work in non-quenched and tempered Si-Mn steel

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Science china(Technological Sciences) 2006年第2期49卷 137-146页

作者： LIU Zhilin1, LIN Cheng1 & WANG Ping2.1. department of Materials and Chemical engineering, Liaoning {2. of technology, Jinzhou 12.001, china 2. Mechanical department, Armor technique {2. of PLA, Changchun 130117, china department of Materials and Chemical engineering Liaoning Institute of Technology Jinzhou China Mechanical department Armor technique Institute of PLA Changchun China

Based on the hot-continuous rolling technology, the finishing rolling impact work α k of the non-quenched and tempered Si-Mn steel is theoretically calculated with the covalent electron number nA of the strongest bond in alloying phases, and the smallest interface electron density difference Δρ of alloying phase interface and the number of atom states σ which keep the interface electron density continuous. Calculations show that the solution strengthening, the precipitation strengthening, and the interface strengthening will result in the decrease of the finishing rolling impact work α k, and the effects of the number of atom states σ which keep the interface electron density continuous on the finishing rolling impact work α k are different. Taking the impact work and the number of atom states σ 0 keeping the electron density continuous of the phase interface α-Fe/α-Fe-C between α-Fe and α-Fe-C as reference values, the impact work of the interface will increase when σ of some interface is larger than σ 0; otherwise, the impact will decrease. Therefore, the finishing rolling impact work α k can be calculated with the impact value of the refined α-Fe matrix and the influence amounts caused by the solution strengthening, the precipitation strengthening, the interface strengthening, and the number of atom states σ which keep the interface electron density continuous. The calculated results agree well with the measured ones. In this paper, the effect of S on the impact work is also discussed.

关键词： electron structure parameters, non-quenched and tempered steel, impact work and calculation.

A complex variable meshless method for fracture problems

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Science china(Physics,Mechanics & Astronomy) 2006年第1期49卷 46-59页

作者： CHENG Yumin1 & LI Jiuhong2.1. Shanghai institute of Applied Mathematics and Mechanics, Shanghai University, Shanghai 2.0072. china 2. {2. of Building engineering, Xi’an University of technology, Xi’an 710048, china Shanghai institute of Applied Mathematics and Mechanics Shanghai University Shanghai China department of Building engineering Xi’an University of Technology Xi’an China

Based on the moving least-square (MLS) approximation, the complex variable moving least-square approximation (CVMLS) is discussed in this paper. The complex variable moving least-square approximation cannot form ill-conditioned equations, and has greater precision and computational efficiency. Using the analytical solution near the tip of a crack, the trial functions in the complex variable moving least-square approxi- mation are extended, and the corresponding approximation function is obtained. And from the minimum potential energy principle, a complex variable meshless method for fracture problems is presented, and the formulae of the complex variable meshless method are obtained. The complex variable meshless method in this paper has greater precision and computational efficiency than the conventional meshless method. Some examples are given.

关键词： moving least-square approximation, complex variable moving least-square approximation, meshless method, complex variable meshless method, fracture.

Dynamic behavior of polymer surface and the time dependence of contact angle

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Science china Chemistry 2005年第6期48卷 553-559页

作者： WANG Xinping1, CHEN Zhifang1 & SHEN Zhiquan2.1. Key Laboratory of Advanced Textile Materials and Manufacturing technology of Education Ministry, department of Applied Chemistry, Zhejiang {2. of Science and technology, Hangzhou 310033, china 2. department of Polymer Science and engineering, Zhejiang University, Hangzhou 31002., china department of Applied Chemistry Zhejiang Institute of Science and Technology Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Education Ministry Hangzhou China department of Polymer Science and engineering Zhejiang University Hangzhou China

Time-dependent contact angles were measured by depositing sessile drops of wa-ter on the polymer surfaces and monitoring the drop shape as a function of time. It was found that contact angles decreased sharply with contact time and the equilibrium contact angle was finally attained after a certain time. Values of starting (θ s) and equilibrium contact angles (θ e) obtained by the sessile drop method depend on polymer properties. The Wilhelmy plate technique was used to measure advancing and receding contact angles. The variations of starting (θ s) and equilibrium contact angles (θ e), advancing (θ a) and receding contact angles (θ r) have been studied on the oxidized surface of polymers containing polybutadiene block to explore the cause of time-dependence in contact angle measurement and the meaning of θ s and θ e. The results showed the linear relationships between starting (θ s) and advancing contact angles (θ a), the equilibrium (θ e) and receding contact angles (θ r). The similar relationship was also established between the contact angle hysteresis (θ a?θ r) and differences (θ s ?θ e) in starting contact angles and equilibrium contact angles. Therefore, time-dependence in contact angle measurement was mainly attributed to the surface reconstruction when water drops were deposited on polymer surfaces. The starting contact angle was contributed by the hydrophobic component on polymer surface and the equilibrium contact angle mainly by the hydrophilic component of polymer. These results not only demonstrated the interdependency between two contact angle measurements, the sessile drop method and the Wilhelmy plate technique, but also provided the experimental evidence to explain the cause of time-dependent contact angle. This may also provide a new method to study dynamic behavior of polymer surface.

关键词： contact angle, surface dynamic behavior, polymer surface, dynamic contact angle, time-dependence.

Early Hydration of Composite Cement with Thermal Activated Coal Gangue

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Journal of Wuhan University of technology(Materials Science) 2010年第1期25卷 162-166页

作者：郭伟 department of Material engineering Yancheng Institute of Technology institute of Material Science and engineering Nanjing University of Technology

Composite cement samples were prepared by mixing clinker, gypsum with burnt coal gangues which was calcined at various temperatures. The mechanical strength and Ca（OH）2.content in the cement paste were tested, and the paste composition and microstructure were analyzed by thermogravimetry-differential thermal analysis （TG-DSC）, X-ray diffraction（XRD）, scanning electronic microscopy （SEM） and pore structure analysis. Results demonstrate that the thermal activated coal gangue could accelerate the early hydration of cement clinker obviously, which promotes the gangue hydration itself. The early hydrated products of the cement are C-S-H gel, Ca（OH）2.and AFt. The cement with 30% （in mass） the gangue exhibits higher mechanical strength, and among all the cement samples the one with the gangue burnt at 700 ℃ displays the highest hydration rate, mechanical strength, the most gel pores and the lowest total porosity.

关键词： blended cement hydration microstructure hydration product

Structure and Pozzolanic Activity of Calcined Coal Gangue during the Process of Mechanical Activation

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Journal of Wuhan University of technology(Materials Science) 2009年第2期24卷 326-329页

作者：郭伟 department of Material engineering Yancheng Institute of Technology institute of Material Science and engineering Nanjing University of Technology

On the basis of analyzing coal gangue＇s chemical and mineral compositions, the structure change of coal gangue during the mechanical activation was investigated by XRD, FTIR, NMR, and the mechanical strength of the cement doped coal gangue with various specific surface area was tested. The experimental results indicate that, the lattice structure of metakaolin in coal gangue samples calcined at 700 ℃ disorganizes gradually and becomes disordered, and the lattice structure of α-quartz is distorted slightly. The pozzolanic activity of the coal gangue increases obviously with its structural disorganization.

关键词： coal gangue mechanical activation structure NMR tetrahedron

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Science china Chemistry 2004年第6期47卷 466-479页

作者： SONG Huajie1,2. XIAO Heming1 & DONG Haishan2.1. department of Chemistry, Nanjing University of Science and technology, Nanjing 2.0094,{2. 2. institute of Chemical Materials,{2. Academy of engineering Physics, Mianyang 62.900,{2. department of Chemistry Nanjing University of Science and Technology Nanjing China institute of Chemical Materials China Academy of Engineering Physics Mianyang China

The symmetry-adapted perturbation theory (SAPT) that has the ability in decompo- sition of the total interaction energy into physically meaningful components is used to provide a more fundamental understanding of intermolecular forces. This work was motivated by the diffi- culty of standard SAPT in computing the intermolecular interactions for large energetic dimer systems. SAPT based on Kohn-Sham orbitals (SAPT(DFT)) proves computationally efficient for these large systems, but has been shown to perform poorly for interaction energy components. The deficiencies of SAPT(DFT) result from wrong asymptotical behaviors of commonly used exchange-correlation potentials. To remove the deficiencies, two asymptotic corrections by means of van Leeuwen and Baerends (LB) model potential and Fermi-Amaldi (FA) type potential were applied into three small test systems comprising He2. HF2.and (N2.2.and a set of larger ni- tramide dimers at several separations. The results showed that when utilizing newly developed frequency-dependent density susceptibilities (FDDS) technique for computing dispersion energy, the FA asymptotic correction is very effective to circumvent these deficiencies in SAPT(DFT) and yields a good accuracy over the LB correction. The FA corrected SAPT(DFT) approach is capa- ble of correctly predicting all the quantitative trends in binding energies for all test cases and substantially reduces computational cost as compared with the standard SAPT calculations. The successful application of the approach to nitramide dimer demonstrates that it potentially pro- vides a good means to calculate accurately intermolecular forces in larger system such as en- ergetic systems.

关键词： intermolecular interaction, density functional theory (DFT), symmetry adapted perturbation theory (SAPT), asymptotic correction, frequency-dependent density susceptibilities (FDDS).

Effect of static magnetic field on activity of immobilized α-amylase

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Chinese Science Bulletin 1997年第2期42卷 127-130页

作者： YAN Liushui, ZHU Yuanbao, HE-Shuang’e and CAO Zhixiang1 department of Chemical engineering, Nanchang {2. of Aeronautical technology, Nanchang 330034, china 2. department of Chemistry and Chemical engineering, Hunan University, Changsha 410082. china department of Chemical engineering Nanchang Institute of Aenwututical Techndogy Nanchang China department of Chemistry and Chemical engineering Hunan University Changsha China

BIOLOGICAL effect of magnetic field is one of the three major subjects of contemporary biomagnetism, and is also the basis of applied biomagnetism. In order to explore magnetic biological effects, the influence of various sorts of magnetic field on many living systems as well as their different constructural levels has been extensively studied. However, only a few studies with in vitro enzyme have been reported, and few researches concerning the influence of magnetic field on immobilized enzyme reactions have been published. This note describes

关键词： static magnetic field immobilized α-amylase enzyme activity oscillatory behaviour.