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3D characterization of porosity and minerals of low-permeability uranium-bearing sandstone based on multi-resolution image fusion

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Nuclear Science and Techniques 2020年第10期31卷 115-134页

作者： Bing Sun shan-shan Hou Sheng Zeng Xin Bai shu-Wen Zhang Jing Zhang School of Civil Engineering University of South ChinaHengyang 421001China School of Resource Environment and Safety Engineering University of South ChinaHengyang 421001China School of Resources and Safety Engineering Central South UniversityChangsha 410083China

In the process of in situ leaching of uranium,the microstructure controls and influences the flow distribution,percolation characteristics,and reaction mechanism of lixivium in the pores of reservoir rocks and directly affects the leaching of useful *** this study,the pore throat,pore size distribution,and mineral composition of low-permeability uranium-bearing sandstone were quantitatively analyzed by high pressure mercury injection,nuclear magnetic resonance,X-ray diffraction,and wavelength-dispersive X-ray *** distribution characteristics of pores and minerals in the samples were qualitatively analyzed using energy-dispersive scanning electron microscopy and multi-resolution CT *** registration with the landmarks algorithm provided by FEI Avizo was used to accurately match the CT images with different *** multi-scale and multi-mineral digital core model of low-permeability uranium-bearing sandstone is reconstructed through pore segmentation and mineral segmentation of fusion core scanning *** results show that the pore structure of low-permeability uranium-bearing sandstone is complex and has multi-scale and multi-crossing *** intergranular pores determine the main seepage channel in the pore space,and the secondary pores have poor connectivity with other *** and coffinite are isolated from the connected pores and surrounded by a large number of clay minerals and ankerite cements,which increases the difficulty of uranium *** and a large amount of ankerite cement are filled in the primary and secondary pores and pore throats of the low-permeability uraniumbearing sandstone,which significantly reduces the porosity of the movable fluid and results in low overall permeability of the *** multi-scale and multi-mineral digital core proposed in this study provides a basis for characterizing macroscopic and microscopic pore-throat structures and mineral distributions of low-permea

关键词： Low-permeability uranium-bearing sandstone Digital core Micro-CT SEM–EDS Image fusion

Robust Text Detection in Natural Scenes Using Text Geometry and Visual Appearance

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International Journal of Automation and computing 2014年第5期11卷 480-488页

作者： Sheng-Ye Yan Xin-xing Xu Qing-shan Liu School of Information and Control Nanjing University of Information Science and Technology School of Computer Engineering Nanyang Technological University

This paper proposes a new two-phase approach to robust text detection by integrating the visual appearance and the geometric reasoning rules. In the first phase, geometric rules are used to achieve a higher recall rate. Specifically, a robust stroke width transform(RSWT) feature is proposed to better recover the stroke width by additionally considering the cross of two strokes and the continuousness of the letter border. In the second phase, a classification scheme based on visual appearance features is used to reject the false alarms while keeping the recall rate. To learn a better classifier from multiple visual appearance features, a novel classification method called double soft multiple kernel learning(DS-MKL) is proposed. DS-MKL is motivated by a novel kernel margin perspective for multiple kernel learning and can effectively suppress the influence of noisy base kernels. Comprehensive experiments on the benchmark ICDAR2005 competition dataset demonstrate the effectiveness of the proposed two-phase text detection approach over the state-of-the-art approaches by a performance gain up to 4.4% in terms of F-measure.

关键词： Text detection geometric rule stroke width transform (SWT) support vector machine (SVM) multiple kernel learning (MKL)

An Optimization Algorithm for Service Composition Based on an Improved FOA

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Tsinghua Science and Technology 2015年第1期20卷 90-99页

作者： Yiwen Zhang Guangming Cui Yan Wang xing Guo shu Zhao the School of Computer Science and Technology Key Laboratory of Intelligent Computing and Signal Processing Ministry of Education Anhui University

Large-scale service composition has become an important research topic in Service-Oriented Computing（SOC）. Quality of Service（Qo S） has been mostly applied to represent nonfunctional properties of web services and to differentiate those with the same functionality. Many studies for measuring service composition in terms of Qo S have been completed. Among current popular optimization methods for service composition, the exhaustion method has some disadvantages such as requiring a large number of calculations and poor scalability. Similarly,the traditional evolutionary computation method has defects such as exhibiting slow convergence speed and falling easily into the local optimum. In order to solve these problems, an improved optimization algorithm, WS FOA（Web Service composition based on Fruit Fly Optimization Algorithm） for service composition, was proposed, on the basis of the modeling of service composition and the FOA. Simulated experiments demonstrated that the algorithm is effective, feasible, stable, and possesses good global searching ability.

关键词： service composition Fruit Fly Optimization Algorithm(FOA) Quality of Service(QoS) index

Numerical analysis on transitions and symmetry-breaking in the wake of a flapping foil

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Acta Mechanica Sinica 2012年第6期28卷 1551-1556页

作者： Guo-Yi He Qi Wang xing Zhang shu-Guang Zhang The School of Aircraft Engineering Nanchang Hangkong University LNM Institute of Mechanics Chinese Academy of Sciences The School of Transportation Science and Engineering Beihang University

Flying and marine animals often use flapping wings or tails to generate thrust. In this paper, we will use the simplest flapping model with a sinusoidal pitching mo- tion over a range of frequency and amplitude to investigate the mechanism of thrust generation. Previous work focuses on the Karman vortex street and the reversed Karman vor- tex street but the transition between two states remains un- known. The present numerical simulation provides a com- plete scenario of flow patterns from the Karman vortex street to reversed Karman vortex street via aligned vortices and the ultimate state is the deflected Karman vortex street, as the parameters of flapping motions change. The results are in agreement with the previous experiment. We make further discussion on the relationship of the observed states with drag and thrust coefficients and explore the mechanism of enhanced thrust generation using flapping motions.

关键词： Flapping motion. Immersed boundary method Wake. Symmetry-breaking

U.S. national parks accessibility and visitation

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Journal of Mountain Science 2019年第12期16卷 2894-2906页

作者： SHEN xing-ju HUANG Rui-hong ZHANG Jin-shan College of Historical Culture&Tourism Southwest Minzu UniversityChengdu 610041China Department of Geography Planningand RecreationNorthern Arizona UniversityFlagstaffAZ 86011-5016USA Key Laboratory of Mountain Hazards and Earth Surface Process Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China

Accessibility is a factor affecting national park ***,the effect of accessibility on national park visitation is not fully *** paper examines the relationship between *** park visitation and ***,the global and local accessibility indexes of each park unit are computed based on an accessibility model that takes into account the surrounding population and its proximity to the park *** in the model is a distance decay coefficient that is derived from *** park visitor surveys and therefore pertinent to the case of *** correlation analysis is performed between park visitation and accessibility based on park types,regions,and visitation *** show that total visitation is positively related to accessibility in National Memorials,Military Parks and Battlefield Parks/Sites but negatively related to accessibility in national parks and national ***,recreational overnight stay visits are commonly negatively correlated to accessibility for almost all park ***,local accessibility index displays enhanced correlation coefficients with improved significance levels in many categories of *** suggest that historical/cultural national parks which often show positive correlations tend to attract more local visitors,but nature-based parks which mainly show negative correlations tend to attract more distant visitors.

关键词： U.S.National Park Accessibility Visitation Distance decay GIS

Clinical features of familial adenomas polyps in Chinese and establishment of its immortal lymphocyte cell lines

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World Journal of Gastroenterology 2007年第20期13卷 2858-2861页

作者： shan-Rong Cai Su-Zhang Zhang shu Zheng Cancer Institute 2^nd Affiliated Hospital School of Medicine Zhejiang University Hangzhou 310009 Zhejiang Province China

AIM： To reserve the rare Chinese familial adenomas polyp （FAP） family resource and to investigate the clinical features of FAP in Chinese for its diagnosis. METHODS： Clinical features of patients with FAP were investigated. If there is any question, their medical records were verified. Blood sample was taken and lymphocyte immortal cell lines were established with modified EB-transformation methods. Congenital hypertrophy of retinal pigment epithelium （CHRPE） was checked by an experienced ophthalmologist. RESULTS： Twenty seven families including 21 classical FAP （CFAP） families, 3 attenuated FAP （AFAP） families, and 3 suspected AFAP families were investigated. A total of 116 lymphocyte immortal cell lines were established from 26 families. In all the FAP families, colorectal cancer occurred at the mean age of 42.84 years. Of the 16 families checked, 15 （93.75%） had CHRPE. The mean number of patients suffering from colorectal neoplasm was 3.14 in CFAP families and 2.0 in AFAP families （P 〈 0.01）. The mean oldest age at diagnosis of FAP was 41.75 years in CFAP families, and 58.67 years in AFAP families, respectively （P 〈 0.01）. Mean age of development of colorectal cancer was 42.23 in CFAP and 57.33 years old in AFAP （P 〈 0.01）. Mean of the earliest age at diagnosis of FAP was 29.95 years in the FAP families with a positive family history and 46.80 years in the FAP families with a negative family history （P 〈 0.01）. The ratio of extra-intestinal tumors to colorectal neoplasms was different in the two kinds of families with positive and negative family history （P 〈 0.01）. CONCLUSION： Additional use of ciclosporin will effectively improve to establish lymphocyte immortal cell lines with modified EB- transformation methods. In Chinese FAP, there was a high frequency of CHRPE, and a later age at diagnosis and a later age of development of colorectal cancer in AFAR And earlier age at diagnosis in FAP with positive family history was also found that will help to diagnos

关键词： Adenomatous polyposis coli Pedigree Phenotype Family history Congenital hypertrophy of retinal pigment epithelium Immortal cell line

A Corrected Solid Boundary Treatment Method for Smoothed Particle Hydrodynamics

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China Ocean Engineering 2017年第2期31卷 238-247页

作者： CHEN Yun-sai ZHENG xing JIN shan-qin DUAN Wen-yang College of Shipbuilding Engineering Harbin Engineering University Harbin 150001 China Department of Technology National Deep Sea Center Qingdao 266061 China

Smoothed Particle Hydrodynamics method （SPFI） has a good adaptability for simulating of free surface flow problems. However, there are some shortcomings of SPH which are still in open discussion. This paper presents a corrected solid boundary handling method for weakly compressible SPH. This improved method is very helpful for numerical stability and pressure distribution. Compared with other solid boundary handling methods, this corrected method is simpler for virtual ghost particle interpolation and the ghost particle evaluation relationship is clearer. Several numerical tests are given, like dam breaking, solitary wave impact and sloshing tank waves. The results show that the corrected solid boundary processing method can recover the spurious oscillations of pressure distribution when simulating the problems with complex geometry boundary.

关键词： SPH particle arrangement boundary treatment solitary wave impact sloshing wave

A New Approach of High OrderWell-Balanced Finite Volume WENO Schemes and Discontinuous Galerkin Methods for a Class of Hyperbolic Systems with Source Terms

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Communications in Computational Physics 2006年第1期1卷 100-134页

作者： Yulong xing Chi-Wang shu Department of Mathematics Brown UniversityProvidenceRI 02912USA Division of Applied Mathematics Brown UniversityProvidenceRI 02912USA

Hyperbolic balance laws have steady state solutions in which the flux gradients are nonzero but are exactly balanced by the source *** our earlier work[31–33],we designed high order well-balanced schemes to a class of hyperbolic systems with separable source *** this paper,we present a different approach to the same purpose:designing high order well-balanced finite volume weighted essentially non-oscillatory(WENO)schemes and RungeKutta discontinuous Galerkin(RKDG)finite element *** make the observation that the traditional RKDG methods are capable of maintaining certain steady states exactly,if a small modification on either the initial condition or the flux is *** computational cost to obtain such a well balanced RKDG method is basically the same as the traditional RKDG *** same idea can be applied to the finite volume WENO *** will first describe the algorithms and prove the well balanced property for the shallow water equations,and then show that the result can be generalized to a class of other balance *** perform extensive one and two dimensional simulations to verify the properties of these schemes such as the exact preservation of the balance laws for certain steady state solutions,the non-oscillatory property for general solutions with discontinuities,and the genuine high order accuracy in smooth regions.

关键词： Hyperbolic balance laws WENO finite volume scheme discontinuous Galerkin method high order accuracy source term conservation laws shallow water equation elastic wave equation chemosensitive movement nozzle flow two phase flow

Density Functional Theory Study of Water Diffusion and Clustering on Pd(111)

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Chinese Journal of Structural Chemistry 2006年第8期25卷 909-914页

作者： CHEN Jin-Wen TU Xue-Yan TIAN Kai DAI shu-shan School of Chemical Science and Technology Yunnan University Kunming 650091 China School of Chemistry. and Biotechnology Yunnan Nationalities University Kunming 650031 China School of Chemistry and Chemical Engineering Hunan Universi of Science and Technology Xiangtan 411201 China

The internal structures as well as adsorption and hopping energies of monomers, dimers, trimers, tetramers, pentamers and hexamers of water on Pd（111） have been studied by density functional theory （DFT） plane-wave pseudopotential method which performs the firstprinciples quantum-mechanical calculations to explore the properties of crystals and surfaces in materials. Based on the calculations, we suppose that their absorption is via one water molecule for monomers, dimmers and trimers, but three water molecules for pentamers and hexamers. Moreover, there is one water molecule bonding with Pd atom by O atom in pentamers and hexamers, which explains why pentamers and hexamers are stable. The binding energies of polymers may be used to explain why the trimer comes close to two nearby monomers to form a stable pentamer instead of tetramer. And the difference of mobility of small water clusters is due to their different hopping energies.

关键词： density functional theory Pd(111) surface water diffusion and clustering binding energy hopping energy