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Effect of modeling factors on the dissolution-diffusion-convection process during CO2 geological storage in deep saline formations

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Frontiers of Earth Science 2013年第2期7卷 238-256页

作者： weizhang National Geological Library of China (Geoscience Documentation Center) China Geological Survey Beijing 100083 China

It is well known that during CO2 geological storage, density-driven convective activity can significantly accelerate the dissolution of injected CO2 into water. This action could limit the escape of supercritical CO2 from the storage formation through vertical pathways such as fractures, faults and abandoned wells, consequently increasing permanence and security of storage. First, we investigated the effect of numerical perturbation caused by time and grid resolution and the convergence criteria on the dissolution-diffusion-convection （DDC） process. Then, using the model with appropriate spatial and temporal resolution, some uncertainty parameters investigated in our previous paper such as initial gas saturation and model boundaries, and other factors such as relative liquid permeability and porosity modification were used to examine their effects on the DDC process. Finally, we compared the effect of 2D and 3D models on the simulation of the DDC process. The above modeling results should contribute to clear understanding and accurate simulation of the DDC process, especially the onset of convective activity, and the CO2 dissolution rate during the convection-dominated stage.

关键词： climate change carbon dioxide geologic sequestration density-driven convection reactive transport modeling grid resolution

内镜下贲门松弛紧缩术联合药物治疗难治性反流性食管炎的临床效果

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中外医药研究 2024年第10期3卷 30-32页

作者：陈芳秦荣陈炜璋柴芳时阮开学东莞市滨海湾中心医院健康管理科广东东莞523900 东莞市滨海湾中心医院消化内科广东东莞523900

目的:分析内镜下贲门松弛紧缩术联合药物治疗难治性反流性食管炎(RGERE)的临床效果.方法:选取2021年10月—2023年3月东莞市滨海湾中心医院收治的RGERE患者60例作为研究对象,随机分为对照组(药物治疗)与试验组(内镜下贲门松弛紧缩术联合... 详细信息

目的:分析内镜下贲门松弛紧缩术联合药物治疗难治性反流性食管炎(RGERE)的临床效果.方法:选取2021年10月—2023年3月东莞市滨海湾中心医院收治的RGERE患者60例作为研究对象,随机分为对照组(药物治疗)与试验组(内镜下贲门松弛紧缩术联合药物治疗),各30例.比较两组干预效果.结果:治疗后,两组食管内pH值、压力高于治疗前,胃食管反流病-健康相关生活质量评分低于治疗前,试验组优于对照组,差异有统计学意义(P<0.05);治疗后,两组病理学积分低于治疗前,试验组低于对照组,差异有统计学意义(P<0.05);试验组总有效率高于对照组,不良反应发生率低于对照组,差异有统计学意义(P<0.05).结论:针对RGERE患者,采取内镜下贲门松弛紧缩术治疗,可缓解临床症状,提高治疗有效率,且安全性较高,可推广.

关键词：难治性反流性食管炎贲门松弛紧缩术内镜黏膜套扎

Color-Redshift Relations and Photometric Redshift Estimations of Quasars in Large Sky Surveys

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Chinese Journal of Astronomy and Astrophysics 2004年第1期4卷 17-27页

作者： Xue-BingWu weizhang XuZhou DepartmentofAstronomy SchoolofPhysicsPekingUniversityBeijing100871 NationalAstronomicalObservatories ChineseAcademyofSciencesBeijing100012

With a recently constructed composite quasar spectrum and the χ2 minimization technique, we describe a general method for estimating the photometric redshifts of a large sample of quasars by deriving theoretical color-redshift relations and comparing the theoretical colors with the observed ones. We estimated the photometric redshifts from the 5-band SDSS photometric data of 18678 quasars in the first major data release of SDSS and compared them with their spectroscopic redshifts. The difference is less than 0.1 for 47 % of the quasars and less than 0.2 for 68 %. Based on the calculation of the theoretical color-color diagrams of stars, galaxies and quasars both on the SDSS system and on the BATC system, we expect that we would be able to select candidates of high redshift quasars more efficaciously with the latter than with the former, provided the BATC survey can detect objects with magnitudes fainter than 21.

关键词： galaxies: photometry quasars: general quasars: emission lines ― surveys

Integration Technology of Micro-LED for Next-Generation Display

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Research 2023年第2期2023卷 389-413页

作者： Dingbo Chen Yu-Chang Chen Guang Zeng David weizhang Hong-Liang Lu State Key Laboratory of ASIC and System Shanghai lnstitute of Inteligent Electronics&SystemsSchoolof MicroelectronicsFudan UniversityShanghai 200433China Jia Shan Fudan Institute jaxingZhejang Province 314100China Key Laboratory of Specialty Fiber Optics and Optical Access Networks Shanghai Institute Communication and Data ScienceShanghai UniversityShanghai 200444China

Inorganic micro light-emitting diodes(micro-LEDs)based on II-V compound semiconductors have been widely studied for self-emissive *** chips to applications,integration technology plays an indispensable role in micro-L... 详细信息

关键词： LED diodes LEDs

Multiple target localization in wireless visual sensor networks

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Frontiers of Computer Science 2013年第4期7卷 496-504页

作者： Wei LI weizhang Research Institute of Electronic Science and Technology University of Electronic Science and Technology of China Chengdu 610054 China

Target localization is an important service in wireless visual sensor networks （WVSN）. Although the problem of single target localization has been intensively studied, few consider the problem of multiple target localization without prior target information in WVSN. In this paper, we first investigate the architecture of WVSN where data transmission is reduced to only target positions. Since target matching is a key issue in the multiple target localization, we propose a statistical method to match corresponding targets to located targets in world coordinates. In addition, we also consider scenarios where occlusion or limited field of view （FOV） occurs. The proposed method utilizes target images to the greatest extent. Our experimental results show that the proposed method obtains a more accurate result in targets localization compared with the camera discard scheme, and saves significant amounts of energy compared with other feature matching schemes.

关键词： target localization statistics wireless visualsensor networks occlusion limited field of view

A Differential Abundance Analysis of HD219175 A and B

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Chinese Journal of Astronomy and Astrophysics 2005年第3期5卷 238-244页

作者： Hua-weizhang GangZhao DepartmentofAstronomy SchoolofPhysicsPekingUniversityBeijing100871 NationalAstronomicalObservatories ChineseAcademyofSciencesBeijing100012

The abundances of the wide binary pair HD 219175 A and B are determined andcompared using a line-by-line differential analysis. No evidence for difference has been found inthe abundances of Fe, O, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Ni, Cu and Ba. Our resultssupport a physical relation between the two components of HD 219175.

关键词： abundances atmospheres visual

Lithium Abundance of Metal-poor Stars

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Chinese Journal of Astronomy and Astrophysics 2003年第5期3卷 453-457页

作者： Hua-weizhang GangZhao DepartmentofAstronomy SchoolofPhysicsPekingUniversityBeijing100871 NationalAstronomicalObservatories ChineseAcademyofSciencesBeijing100012

High-resolution, high signal-to-noise ratio spectra have been obtained for 32 metal-poor stars. The equivalent widths of Li γ6708 ? were measured and the lithium abundances were derived. The average lithium abundance of 21 stars on the lithium plateau is 2.33±0.02 dex. The Lithium plateau exhibits a marginal trend along metallicity, dA(Li)/d[Fe/H] = 0.12±0.06, and no clear trend with the effective temperature. The trend indicates that the abundance of lithium plateau may not be primordial and that a part of the lithium was produced in Galactic Chemical Evolution (GCE).

关键词： stars: abundances stars: Population II galaxy: evolution

Fault Tolerant Algorithm Based on Dynamic and Active Load Balancing for Redundant Services

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Journal of Computer Science & Technology 2004年第6期19卷 769-775页

作者： Jun-FengTian Jun-weizhang Feng-XianWang DepartmentofComputerScienceandTechnology UniversityofScienceandTechnologyofChinaHefei230027P.R.China MathematicsandComputerCollege HebeiUniversityBaoding071002P.R.China

A new Some-Read-Any-Write (SRAW) fault tolerant algorithm for redudant services is presented that allows a system to adjust failures dynamically in order to keep the availability and improve the performance. SRAW is based upon dynamic and active load balancing. By introducing dynamic and active load balancing scheme into redundant services, not only the processing speed of requests can be greatly improved, but also the load balancing can be simply and efficiently achieved. Integrated with consistency protocol in this paper, SRAW can also be applied to state services. The performance of SRAW algorithm is also analyzed, and comparisons with other fault tolerant algorithms, expecially with RAWA, indicate that SRAW efficiently improves the performance of redundant services with guaranteeing system availability. Keywords redundant service - fault tolerant - active - load balancing - quorum Supported by the Hebei Province Natural Science Foundation of China under Grant No.600091.Jun-Feng Tian received the B.S. degree in electrical engineering and the M.S. degree in computer application both from Hebei University, in 1986 and in 1995 respectively. Currently, he is a Ph.D. candidate in University of Science and Technology of China. He is a professor at Hebei University. His current research interests include network technology, system architecture and distributed computing.Jun-Wei Zhang was born in 1977 and received the B.S. and M.S. degrees in computer application from Hebei University, P.R. China, in 2000 and 2003, respectively. His current research interests include software fault tolerance and load balancing.Feng-Xian Wang received the B.S. degree in electrical engineering from Hebei University, P.R. China, in 1978. He is a professor in Hebei University. His current research interests include network security and distributed computing.

关键词： redundant service fault tolerant active load balancing quorum

Discrete Maximum Principle and a Delaunay-Type Mesh Condition for Linear Finite Element Approximations of Two-Dimensional Anisotropic Diffusion Problems

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Numerical Mathematics(Theory,Methods and Applications) 2011年第3期4卷 319-334页

作者： weizhang Huang Department of Mathematics the University of KansasLawrenceKS 66045USA.

A Delaunay-type mesh condition is developed for a linear finite element approximation of two-dimensional anisotropic diffusion problems to satisfy a discrete maximum *** condition is weaker than the existing anisotropic non-obtuse angle condition and reduces to the well known Delaunay condition for the special case with the identity diffusion *** results are presented to verify the theoretical findings.

关键词： Anisotropic diffusion discrete maximum principle finite element mesh generation Delaunay triangulation Delaunay condition.