期刊文献+
共找到2,351篇文章
< 1 2 118 >
每页显示 20 50 100
Three-dimensional Holographic Vector of Atomic Interaction Field(3D-HoVAIF) for the QSPR/QSAR of Polychlorinated Naphthalenes 被引量:1
1
作者 李正华 陈刚 +3 位作者 陈志涛 夏之宁 程凡圣 陈华 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2012年第3期345-352,共8页
Three-dimensional holographic vector of atomic interaction field(3D-HoVAIF) is used to describe the chemical structures of polychlorinated naphthalenes(PCNs).After variable screening by stepwise multiple regressio... Three-dimensional holographic vector of atomic interaction field(3D-HoVAIF) is used to describe the chemical structures of polychlorinated naphthalenes(PCNs).After variable screening by stepwise multiple regression(SMR) technique,the liner relationships between gas-chromatographic relative retention time(RRT),298 K supercooled liquid pressures(logPL),n-octanol/air partition coefficient(logKOA),n-octanol/water partition coefficient(logKOW),aqueous solubilities(logSW),relative in vitro potency values(-logEROD) of PCNs and 3D-HoVAIF descriptors have been established by partial least-square(PLS) regression.The result shows that the 3D-HoVAIF descriptors can be well used to express the quantitative structure-property(activity) relationships of PCNs.Predictive capability of the models has also been demonstrated by leave-one-out cross-validation.Moreover,the predicted values have been presented for those PCNs which are lack of experimentally physico-chemical properties and biological activity by the optimum models. 展开更多
关键词 polychlorinated naphthalenes three-dimensional holographic vector of atomic interaction field QSPR QSAR
下载PDF
QSAR Study on Some N-[5-(2-Furanyl)-2-methyl-4-oxo-4H-thieno[2,3-d]pyrimidin-3-yl]-carboxamide and 3-Substituted-5-(2-furanyl)-2-methyl-3H-thieno-[2,3-d]pyrimidin-4-ones Using Three-dimensional Holographic Vector of Atomic Interaction Field 被引量:1
2
作者 杨善彬 夏之宁 +4 位作者 梅虎 潘元 杨青林 许罗楠 李志良 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2009年第10期1197-1204,共8页
Study on the quantitative structure-activity relationship (QSAR) of 26 compounds, N-[5-(2-furanyl)-2-methyl-4-oxo-4H-thieno[2,3-d]pyrimidin-3-yl]-carboxamide and 3-substituted- 5-(2-furanyl)-2-methyl-3H-thieno[2... Study on the quantitative structure-activity relationship (QSAR) of 26 compounds, N-[5-(2-furanyl)-2-methyl-4-oxo-4H-thieno[2,3-d]pyrimidin-3-yl]-carboxamide and 3-substituted- 5-(2-furanyl)-2-methyl-3H-thieno[2,3-d]pyrimidin-4-ones, with three-dimensional holographic vector of atomic interaction field (3D-HoVAIF) was carried out. SMR-PLS QSAR models have been created and good correlation coefficients and cross-validated correlation coefficients were obtained. The result shows that the models have good prediction capability and favorable stability and the 3D-HoVAIF is applicable to the molecular structural characterization and biological activity prediction. 展开更多
关键词 three-dimenslonal holographic vector of atomic interaction field (3D-HoVAIF) thienopyrimidones quantitative structure-activity relationship (QSAR)
下载PDF
Three-Dimensional Vector Field Visualization Based on Tensor Decomposition
3
作者 梁训东 李斌 刘慎权 《Journal of Computer Science & Technology》 SCIE EI CSCD 1996年第5期452-460,共9页
This paper presents a visualization method called the deformed cube for visualizing 3D velocity vector field. Based on the decomposition of the tensor which describes the changes of the velocity it provides a teclmiqu... This paper presents a visualization method called the deformed cube for visualizing 3D velocity vector field. Based on the decomposition of the tensor which describes the changes of the velocity it provides a teclmique for visualizing local flow. A deformed cube, a cube transformed by a tensor in a local coordinate frame, shows the local stretch, shear and rigid body rotation of the local flow corresponding to the decomposed component of the tensor. Users can interactively view the local deformation or any component of the changes.The animation of the deformed cube moving along a streamline achieves a more global impression of the flow field. This method is intended as a complement to global visualization methods. 展开更多
关键词 Scientific visualization vector field tensor field computer graphics computational fluid dynamics
原文传递
Three-dimensional modulations on the states of polarization of light fields 被引量:2
4
作者 Peng Li Dongjing Wu +5 位作者 Sheng Liu Yi Zhang Xuyue Guo Shuxia Qi Yu Li Jianlin Zhao 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第11期202-214,共13页
Light fields with spatially structured states of polarization(SoPs) are gathering increasing attention because of their potential applications from optical imaging and micromanipulation to classical and quantum comm... Light fields with spatially structured states of polarization(SoPs) are gathering increasing attention because of their potential applications from optical imaging and micromanipulation to classical and quantum communications. Meanwhile,the concepts within structured light fields have been extended and applied to acoustic, electron, and matter waves. In this article, we review recent developments of the SoP modulation of light fields, especially focusing on three-dimensional(3 D) modulations on the SoPs of light fields. The recent progress and novel implementations based on 3 D spin-dependent separation are discussed. Following the discussions to this physical phenomenon, we then describe recent developments on the vector fields with 3 D structured SoP and intensity distributions, namely, 3 D vector fields. The discussed phenomena inspire us to explore other structured light fields for the expansion of applications in biomedical, information science,quantum optics, and so on. 展开更多
关键词 POLARIZATION PHASE vector field spin-orbit interaction
下载PDF
A solution method for decomposing vector fields in Hamilton energy
5
作者 Xin Zhao Ming Yi +2 位作者 Zhou-Chao Wei Yuan Zhu Lu-Lu Lu 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第9期645-653,共9页
Hamilton energy,which reflects the energy variation of systems,is one of the crucial instruments used to analyze the characteristics of dynamical systems.Here we propose a method to deduce Hamilton energy based on the... Hamilton energy,which reflects the energy variation of systems,is one of the crucial instruments used to analyze the characteristics of dynamical systems.Here we propose a method to deduce Hamilton energy based on the existing systems.This derivation process consists of three steps:step 1,decomposing the vector field;step 2,solving the Hamilton energy function;and step 3,verifying uniqueness.In order to easily choose an appropriate decomposition method,we propose a classification criterion based on the form of system state variables,i.e.,type-I vector fields that can be directly decomposed and type-II vector fields decomposed via exterior differentiation.Moreover,exterior differentiation is used to represent the curl of low-high dimension vector fields in the process of decomposition.Finally,we exemplify the Hamilton energy function of six classical systems and analyze the relationship between Hamilton energy and dynamic behavior.This solution provides a new approach for deducing the Hamilton energy function,especially in high-dimensional systems. 展开更多
关键词 Hamilton energy dynamical systems vector field exterior differentiation
下载PDF
A contrastive study on the influences of radial and three-dimensional satellite gravity gradiometry on the accuracy of the Earth's gravitational field recovery 被引量:5
6
作者 郑伟 许厚泽 +1 位作者 钟敏 员美娟 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第10期577-584,共8页
The accuracy of the Earth's gravitational field measured from the gravity field and steady-state ocean circulation explorer(GOCE),up to 250 degrees,influenced by the radial gravity gradient V zz and three-dimension... The accuracy of the Earth's gravitational field measured from the gravity field and steady-state ocean circulation explorer(GOCE),up to 250 degrees,influenced by the radial gravity gradient V zz and three-dimensional gravity gradient V ij from the satellite gravity gradiometry(SGG) are contrastively demonstrated based on the analytical error model and numerical simulation,respectively.Firstly,the new analytical error model of the cumulative geoid height,influenced by the radial gravity gradient V zz and three-dimensional gravity gradient V ij are established,respectively.In 250 degrees,the GOCE cumulative geoid height error measured by the radial gravity gradient V zz is about 2 1/2 times higher than that measured by the three-dimensional gravity gradient V ij.Secondly,the Earth's gravitational field from GOCE completely up to 250 degrees is recovered using the radial gravity gradient V zz and three-dimensional gravity gradient V ij by numerical simulation,respectively.The study results show that when the measurement error of the gravity gradient is 3×10 12 /s 2,the cumulative geoid height errors using the radial gravity gradient V zz and three-dimensional gravity gradient V ij are 12.319 cm and 9.295 cm at 250 degrees,respectively.The accuracy of the cumulative geoid height using the three-dimensional gravity gradient V ij is improved by 30%-40% on average compared with that using the radial gravity gradient V zz in 250 degrees.Finally,by mutual verification of the analytical error model and numerical simulation,the orders of magnitude from the accuracies of the Earth's gravitational field recovery make no substantial differences based on the radial and three-dimensional gravity gradients,respectively.Therefore,it is feasible to develop in advance a radial cold-atom interferometric gradiometer with a measurement accuracy of 10 13 /s 2-10 15 /s 2 for precisely producing the next-generation GOCE Follow-On Earth gravity field model with a high spatial resolution. 展开更多
关键词 GOCE GOCE Follow-On radial and three-dimensional gravity gradients satellite gravity gradiometry Earth's gravitational field
下载PDF
Vector magnetometry in zero bias magnetic field using nitrogen-vacancy ensembles
7
作者 Chunxing Li Fa-Zhan Shi +1 位作者 Jingwei Zhou Peng-Fei Wang 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第10期21-29,共9页
The application of the vector magnetometry based on nitrogen-vacancy(NV)ensembles has been widely investigatedin multiple areas.It has the superiority of high sensitivity and high stability in ambient conditions with ... The application of the vector magnetometry based on nitrogen-vacancy(NV)ensembles has been widely investigatedin multiple areas.It has the superiority of high sensitivity and high stability in ambient conditions with microscale spatialresolution.However,a bias magnetic field is necessary to fully separate the resonance lines of optically detected magneticresonance(ODMR)spectrum of NV ensembles.This brings disturbances in samples being detected and limits the rangeof application.Here,we demonstrate a method of vector magnetometry in zero bias magnetic field using NV ensembles.By utilizing the anisotropy property of fluorescence excited from NV centers,we analyzed the ODMR spectrum of NVensembles under various polarized angles of excitation laser in zero bias magnetic field with a quantitative numerical modeland reconstructed the magnetic field vector.The minimum magnetic field modulus that can be resolved accurately is downto~0.64 G theoretically depending on the ODMR spectral line width(1.8 MHz),and~2 G experimentally due to noisesin fluorescence signals and errors in calibration.By using 13C purified and low nitrogen concentration diamond combinedwith improving calibration of unknown parameters,the ODMR spectral line width can be further decreased below 0.5 MHz,corresponding to~0.18 G minimum resolvable magnetic field modulus. 展开更多
关键词 vector magnetometry NV ensembles optically detected magnetic resonance(ODMR) zero bias magnetic field
下载PDF
Theory,technology and practice of shale gas three-dimensional development:A case study of Fuling shale gas field in Sichuan Basin,SW China 被引量:2
8
作者 SUN Huanquan CAI Xunyu +5 位作者 HU Degao LU Zhiyong ZHAO Peirong ZHENG Aiwei LI Jiqing WANG Haitao 《Petroleum Exploration and Development》 SCIE 2023年第3期651-664,共14页
In the Jiaoshiba block of the Fuling shale gas field,the employed reserves and recovery factor by primary well pattern are low,no obvious barrier is found in the development layer series,and layered development is dif... In the Jiaoshiba block of the Fuling shale gas field,the employed reserves and recovery factor by primary well pattern are low,no obvious barrier is found in the development layer series,and layered development is difficult.Based on the understanding of the main factors controlling shale gas enrichment and high production,the theory and technology of shale gas three-dimensional development,such as fine description and modeling of shale gas reservoir,optimization of three-dimensional development strategy,highly efficient drilling with dense well pattern,precision fracturing and real-time control,are discussed.Three-dimensional development refers to the application of optimal and fast drilling and volume fracturing technologies,depending upon the sedimentary characteristics,reservoir characteristics and sweet spot distribution of shale gas,to form"artificial gas reservoir"in a multidimensional space,so as to maximize the employed reserves,recovery factor and yield rate of shale gas development.In the research on shale gas three-dimensional development,the geological+engineering sweet spot description is fundamental,the collaborative optimization of natural fractures and artificial fractures is critical,and the improvement of speed and efficiency in drilling and fracturing engineering is the guarantee.Through the implementation of three-dimensional development,the overall recovery factor in the Jiaoshiba block has increased from 12.6%to 23.3%,providing an important support for the continuous and stable production of the Fuling shale gas field. 展开更多
关键词 shale gas three-dimensional development Fuling shale gas field Sichuan Basin fine reservoir description precision fracturing recoveryfactor
下载PDF
EXPERIMENTAL INVESTIGATION FOR THE EFFECT OF ROTATION ON THREE-DIMENSIONAL FLOW FIELD IN FILM-COOLED TURBINE 被引量:2
9
作者 YUAN Feng ZHU Xiaocheng DU Zhaohui 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2007年第1期10-15,共6页
An experimental investigation of three-dimensional flow field in a film-cooled turbine model is carried out by using particle image velocimeter (PIV) in a low-speed wind tunnel. The effects of different blowing rati... An experimental investigation of three-dimensional flow field in a film-cooled turbine model is carried out by using particle image velocimeter (PIV) in a low-speed wind tunnel. The effects of different blowing ratios (M=1.5, 2) on the flow field are studied. The experimental results reveal the classical phenomena of the formation of kidney vortex pair and secondary flow in wake region behind the jet hole. And the changes of the kidney vortex pair and the wake at different locations away from the hole on the suction and pressure sides are also studied. Compared with the flow field in stationary cascade, there are centrifugal force and Coriolis force existing in the flow field of rotating turbine, and these forces bring the radial velocity in the jet flow. The effect of rotatien on the flow field of the pressure side is more distinct than that on the suction side from the measured flow fields in Y-Z plane and radial velocity contours. The increase of blowing ratio makes the kidney vortex pair and the secondary flow in the wake region stronger and makes the range of the wake region enlarged. 展开更多
关键词 Film-cooled turbine rotor PIV measurement Blowing ratio three-dimensional flow field
下载PDF
Study of the geomagnetic field's regional gradients in Chinese continent using three-dimensional surface Spline model
10
作者 Yan Feng YiJun Li +3 位作者 JinYan Zhang Shuang Liu Abbas Nasir Ya Huang 《Earth and Planetary Physics》 EI CSCD 2023年第1期74-83,共10页
We combined domestic ground-based and satellite magnetic measurements to create a regional three-dimensional surface Spline(3DSS)gradient model of the main geomagnetic field over the Chinese continent.To improve the p... We combined domestic ground-based and satellite magnetic measurements to create a regional three-dimensional surface Spline(3DSS)gradient model of the main geomagnetic field over the Chinese continent.To improve the precision of the model,we considered the data gap between the ground and satellite data.We compared and analyzed the results of the Taylor polynomial,surface Spline,and CHAOS-6(the CHAMP,?rsted and SAC-C model of Earth’s magnetic field)gradient models.Results showed that the gradients in the south-north and east-west directions of the four models were consistent.The 3DSS model was able to express not only gradients at different altitudes,but also average gradients inside the research area.The two Spline models were able to capture more information on gradient anomalies than were the fitted models.Strong local anomalies were observed in northern Xinjiang,Beijing,and the junction area between Jiangsu and Zhejiang,and the total intensity F decreased whereas the altitude increased.The gradient decreased by 21.69%in the south-north direction and increased by 11.78%in the east-west direction.In addition,the altitude gradient turned from negative to positive while the altitude increased.The Spline model and the two fitted models differed mainly in the field sources they expressed and the modeling theory. 展开更多
关键词 geomagnetic field main field gradients regional model three-dimensional modeling
下载PDF
Three-Dimensional Stress Fields in Finite Thickness Plate with Hole Under Shear Load
11
作者 戴隆超 王鑫伟 +1 位作者 龚俊杰 顾乡 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2014年第5期546-551,共6页
The theoretical solutions are obtained for the three-dimensional(3-D)stress field in an infinite isotropic elastic plate with a through-the-thickness circular hole subjected to shear load at far field by using Kane an... The theoretical solutions are obtained for the three-dimensional(3-D)stress field in an infinite isotropic elastic plate with a through-the-thickness circular hole subjected to shear load at far field by using Kane and Mindlin′s assumption based on the stress function method.Based on the present solutions,the characteristics of 3-D stress field are analyzed and the emphasis is placed on the effects of the plate thickness and Poisson′s ratio on the deviation of the present 3-D in-plane stress from the related plane stress solutions,the stress concentration and the out-of-plane constraint.The present solutions show that the stress concentration factor reaches its peak value of about 8.9% which is higher than that of the plane stress solutions.As expected,the out-of-plane stress constraint factor can reach 1on the surface of the hole when the plate is a very thick one. 展开更多
关键词 three-dimensional stress field through-the-thickness circular hole thickness effect stress concentration out-of-plane constraint
下载PDF
Controlling Three-Dimensional Electron-Electron Correlation via Elliptically Polarized Intense Laser Field
12
作者 Jian-Xing Hao Xiao-Lei Hao +2 位作者 Wei-Dong Li Shi-Lin Hu Jing Chen 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第4期30-34,共5页
The three-dimensional electron-electron correlation in an elliptically polarized laser field is investigated based on a semiclassical model. Asymmetry parameter α of the correlated electron momentum distribution is u... The three-dimensional electron-electron correlation in an elliptically polarized laser field is investigated based on a semiclassical model. Asymmetry parameter α of the correlated electron momentum distribution is used to quantitatively describe the electron-electron correlation. The dependence of α on elliptieity e is totally different in three directions. For the z direction (maJor polarization direction), α first increases and reaches a maximum at ε = 0.275, then it decreases quickly. For the y direction in which the laser field is always absent, the ellipticity has a minor effect, and the asymmetry parameter fluctuates around α = -0.15. However, for the x direction (minor polarization direction), α increases monotonously with ellipticity though starts from the same value as in the y direction when ε = 0. The behavior of α in the x direction actually indicates a transformation from the Coulomb interaction dominated correlation to the laser field dominated correlation. Therefore, our work provides an efficient way to control the three-dimensional electron electron correlation via an elliptically polarized intense laser field. 展开更多
关键词 Controlling three-dimensional Electron-Electron Correlation via Elliptically Polarized Intense Laser field RII
下载PDF
Three-dimensional stochastic seepage field for embankment engineering
13
作者 Ya-jun WANG Wo-hua ZHANG +1 位作者 Chang-yu WU Da-chun REN 《Water Science and Engineering》 EI CAS 2009年第1期58-73,共16页
Owing to the complexity of geo-engineering seepage problems influenced by different random factors, three-dimensional simulation and analysis of the stochastic seepage field plays an important role in engineering appl... Owing to the complexity of geo-engineering seepage problems influenced by different random factors, three-dimensional simulation and analysis of the stochastic seepage field plays an important role in engineering applications. A three-dimensional anisotropic heterogeneous steady random seepage model was developed on the basis of the finite element method. A statistical analysis of the distribution characteristics of soil parameters sampled from the main embankment of the Yangtze River in the Southern Jingzhou zone of China was conducted. The Kolomogorov-Smirnov test verified the statistical hypothesis that the permeability coefficient tensor has a Gaussian distribution. With the help of numerical analysis of the stochastic seepage field using the developed model, various statistical and random characteristics of the stochastic seepage field of the main embankment of the Yangtze River in the Southern Jingzhou zone of China were investigated. The model was also examined with statistical testing. Through the introduction of random variation of the upstream and downstream water levels into the model, the effects of the boundary randomness due to variation of the downstream and upstream water levels on the variation of simulated results presented with a vector series of the random seepage field were analyzed. Furthermore, the combined influence of the variation of the soil permeability coefficient and such seepage resistance measures as the cut-off wall and relief ditch on the hydraulic head distribution was analyzed and compared with the results obtained by determinate analysis. Meanwhile, sensitivities of the hydraulic gradient and downstream exit height to the variation of boundary water level were studied. The validity of the simulated results was verified by stochastic testing and measured data. The developed model provides more detail and a full stochastic algorithm to characterize and analyze three-dimensional stochastic seepage field problems. 展开更多
关键词 anisotropic random seepage field three-dimensional seepage finite element method Monte Carlo simulation inhomogeneous permeability coefficient stochastic disturbance of hydraulic head boundary
下载PDF
Automated measurement of three-dimensional cerebral cortical thickness in Alzheimer’s patients using localized gradient vector trajectory in fuzzy membership maps
14
作者 Chiaki Tokunaga Hidetaka Arimura +9 位作者 Takashi Yoshiura Tomoyuki Ohara Yasuo Yamashita Kouji Kobayashi Taiki Magome Yasuhiko Nakamura Hiroshi Honda Hideki Hirata Masafumi Ohki Fukai Toyofuku 《Journal of Biomedical Science and Engineering》 2013年第3期327-336,共10页
Our purpose in this study was to develop an automated method for measuring three-dimensional (3D) cerebral cortical thicknesses in patients with Alzheimer’s disease (AD) using magnetic resonance (MR) images. Our prop... Our purpose in this study was to develop an automated method for measuring three-dimensional (3D) cerebral cortical thicknesses in patients with Alzheimer’s disease (AD) using magnetic resonance (MR) images. Our proposed method consists of mainly three steps. First, a brain parenchymal region was segmented based on brain model matching. Second, a 3D fuzzy membership map for a cerebral cortical region was created by applying a fuzzy c-means (FCM) clustering algorithm to T1-weighted MR images. Third, cerebral cortical thickness was three- dimensionally measured on each cortical surface voxel by using a localized gradient vector trajectory in a fuzzy membership map. Spherical models with 3 mm artificial cortical regions, which were produced using three noise levels of 2%, 5%, and 10%, were employed to evaluate the proposed method. We also applied the proposed method to T1-weighted images obtained from 20 cases, i.e., 10 clinically diagnosed AD cases and 10 clinically normal (CN) subjects. The thicknesses of the 3 mm artificial cortical regions for spherical models with noise levels of 2%, 5%, and 10% were measured by the proposed method as 2.953 ± 0.342, 2.953 ± 0.342 and 2.952 ± 0.343 mm, respectively. Thus the mean thicknesses for the entire cerebral lobar region were 3.1 ± 0.4 mm for AD patients and 3.3 ± 0.4 mm for CN subjects, respectively (p < 0.05). The proposed method could be feasible for measuring the 3D cerebral cortical thickness on individual cortical surface voxels as an atrophy feature in AD. 展开更多
关键词 Alzheimer’s Disease (AD) Fuzzy C-MEANS Clustering (FCM) three-dimensional CEREBRAL CORTICAL Thickness LOCALIZED Gradient vector
下载PDF
Three-dimensional Monte Carlo simulation of bulk fin field effect transistor
15
作者 王骏成 杜刚 +2 位作者 魏康亮 张兴 刘晓彦 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第11期421-426,共6页
In this paper, we investigate the performance of the bulk fin field effect transistor (FinFET) through a three- dimensional (3D) full band Monte Carlo simulator with quantum correction. Several scattering mechanis... In this paper, we investigate the performance of the bulk fin field effect transistor (FinFET) through a three- dimensional (3D) full band Monte Carlo simulator with quantum correction. Several scattering mechanisms, such as the acoustic and optical phonon scattering, the ionized impurity scattering, the impact ionization scattering and the surface roughness scattering are considered in our simulator. The effects of the substrate bias and the surface roughness scattering near the Si/SiO2 interface on the performance of bulk FinFET are mainly discussed in our work. Our results show that the on-current of bulk FinFET is sensitive to the surface roughness and that we can reduce the substrate leakage current by modulating the substrate bias voltage. 展开更多
关键词 bulk fin field effect transistor (FinFET) three-dimensional (3D) Monte Carlo simulation surface roughness scattering substrate bias effect
下载PDF
VISUALIZATION OF THREE-DIMENSIONAL DATA FIELD AND ITS APPLICATION IN MACHINE TESTING
16
作者 YIN Aijun QIN Shuren TANG Baoping 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2006年第1期81-84,共4页
In order to realize visualization of three-dimensional data field (TDDF) in instrument, two methods of visualization of TDDF and the usual manner of quick graphic and image processing are analyzed. And how to use Op... In order to realize visualization of three-dimensional data field (TDDF) in instrument, two methods of visualization of TDDF and the usual manner of quick graphic and image processing are analyzed. And how to use OpenGL technique and the characteristic of analyzed data to construct a TDDF, the ways of reality processing and interactive processing are described. Then the medium geometric element and a related realistic model are constructed by means of the first algorithm. Models obtained for attaching the third dimension in three-dimensional data field are presented. An example for TDDF realization of machine measuring is provided. The analysis of resultant graphic indicates that the three-dimensional graphics built by the method developed is featured by good reality, fast processing and strong interaction 展开更多
关键词 Visualization in scientific computing three-dimensional data field (TDDF) Test
下载PDF
Three-Dimensional Phase Field Simulations of Hysteresis and Butterfly Loops by the Finite Volume Method
17
作者 席丽莹 陈焕铭 +3 位作者 郑富 高华 童洋 马治 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第9期128-131,共4页
Three-dimensional simulations of ferroelectric hysteresis and butterfly loops are carried out based on solving the time dependent Ginzburg-Landau equations using a finite volume method. The influence of externally mec... Three-dimensional simulations of ferroelectric hysteresis and butterfly loops are carried out based on solving the time dependent Ginzburg-Landau equations using a finite volume method. The influence of externally mechanical loadings with a tensile strain and a compressive strain on the hysteresis and butterfly loops is studied numerically. Different from the traditional finite element and finite difference methods, the finite volume method is applicable to simulate the ferroelectric phase transitions and properties of ferroelectric materials even for more realistic and physical problems. 展开更多
关键词 three-dimensional Phase field Simulations of Hysteresis and Butterfly Loops by the Finite Volume Method
下载PDF
Integration system research and development for three-dimensional laser scanning information visualization in goaf 被引量:1
18
作者 罗周全 黄俊杰 +2 位作者 罗贞焱 汪伟 秦亚光 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第7期1985-1994,共10页
An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, clo... An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, cloud data de-noising optimization, construction, display and operation of three-dimensional model, model editing, profile generation, calculation of goaf volume and roof area, Boolean calculation among models and interaction with the third party soft ware. Concerning this system with a concise interface, plentiful data input/output interfaces, it is featured with high integration, simple and convenient operations of applications. According to practice, in addition to being well-adapted, this system is favorably reliable and stable. 展开更多
关键词 GOAF laser scanning visualization integration system 1 Introduction The goaf formed through underground mining of mineral resources is one of the main disaster sources threatening mine safety production [1 2]. Effective implementation of goaf detection and accurate acquisition of its spatial characteristics including the three-dimensional morphology the spatial position as well as the actual boundary and volume are important basis to analyze predict and control disasters caused by goaf. In recent years three-dimensional laser scanning technology has been effectively applied in goaf detection [3 4]. Large quantities of point cloud data that are acquired for goaf by means of the three-dimensional laser scanning system are processed relying on relevant engineering software to generate a three-dimensional model for goaf. Then a general modeling analysis and processing instrument are introduced to perform subsequent three-dimensional analysis and calculation [5 6]. Moreover related development is also carried out in fields such as three-dimensional detection and visualization of hazardous goaf detection and analysis of unstable failures in goaf extraction boundary acquisition in stope visualized computation of damage index aided design for pillar recovery and three-dimensional detection
下载PDF
Three-dimensional arbitrarily anisotropic modeling for time-domain airborne electromagnetic surveys 被引量:2
19
作者 黄威 贲放 +5 位作者 殷长春 孟庆敏 李文杰 廖桂香 吴珊 西永在 《Applied Geophysics》 SCIE CSCD 2017年第3期431-440,462,共11页
Electrically anisotropic strata are abundant in nature, so their study can help our data interpretation and our understanding of the processes of geodynamics. However, current data processing generally assumes isotrop... Electrically anisotropic strata are abundant in nature, so their study can help our data interpretation and our understanding of the processes of geodynamics. However, current data processing generally assumes isotropic conditions when surveying anisotropic structures, which may cause discrepancies between reality and electromagnetic data interpretation. Moreover, the anisotropic interpretation of the time-domain airborne electromagnetic (TDAEM) method is still confined to one dimensional (1D) cases, and the corresponding three-dimensional (3D) numerical simulations are still in development. In this study, we expanded the 3D TDAEM modeling of arbitrarily anisotropic media. First, through coordinate rotation of isotropic conductivity, we obtained the conductivity tensor of an arbitrary anisotropic rock. Next, we incorporated this into Maxwell's equations, using a regular hexahedral grid of vector finite elements to subdivide the solution area. A direct solver software package provided the solution for the sparse linear equations that resulted. Analytical solutions were used to verify the accuracy and feasibility of the algorithm. The proven model was then applied to analyze the effects of arbitrary anisotropy in 3D TDAEM via the distribution of responses and amplitude changes, which revealed that different anisotropy situations strongly affected the responses of TDAEM. 展开更多
关键词 three-dimensional time-domain airborne electromagnetic arbitrary anisotropy vector finite element
下载PDF
VECTOR BUNDLE, KILLING VECTOR FIELD AND PONTRYAGIN NUMBERS
20
作者 周建伟 《苏州大学学报(自然科学版)》 CAS 1991年第2期131-139,共9页
Let E be a vector bundle over a compact Riemannian manifold M. We construct a natural metric on the bundle space E and discuss the relationship between the killing vector fields of E and M. Then we give a proof of the... Let E be a vector bundle over a compact Riemannian manifold M. We construct a natural metric on the bundle space E and discuss the relationship between the killing vector fields of E and M. Then we give a proof of the Bott-Baum-Cheeger Theorem for vector bundle E. 展开更多
关键词 向量丛 KILLING向量场 PONTRYAGIN数 RIEMANN流形
下载PDF
上一页 1 2 118 下一页 到第
使用帮助 返回顶部