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Search Results: 1 - 10 of 339532 matches for " 李周清 "
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基于PPR和SVM模型研究洞庭湖径流与输沙量变化
Study on Runoff and Sediment Variation of the Dongting Lake Based on PPR and SVM Model
 [PDF]

赵姗, , 正最
Journal of Water Resources Research (JWRR) , 2012, DOI: 10.12677/JWRR.2012.15053
Abstract: 洞庭湖是长江中游典型的吞吐型调蓄湖泊。受自然和人为因素影响,其输入和输出的径流与输沙量关系先后发生了多次大的调整过程。为了探明洞庭湖水沙出入湖量变化和相互关系,本文利用现有水文泥沙等观测试验资料,基于投影寻踪回归(PPR)和支持向量机模型(SVM)对洞庭湖径流与输沙量变化特征进行了模拟和验证,并对模拟误差进行了对比。结果表明,两种模型均可以用于模拟洞庭湖水网径流与输沙量关系,但支持向量机模型(SVM)精确度较高,适用性较好,可为洞庭湖的综合整治提供理论支撑和科学依据。
The Dongting Lake is very important for flood storage and water sources in the midstream of the Yangtze River. Due to the dual effects of nature and human activities, several major changes have been taken place on the runoff and sediment conditions and the relationships between rivers and lakes successively. In order to explore the relationships of runoff and sediment in and out the lake, the existing hydrologic and sediment and other observation data of the Dongting Lake area are fully used, and two non-linear simulation models, Projection Pursuit Regression (PPR) and Support Vector Machine (SVM) are established. The simulation errors are also compared. The results show that the Support Vector Machine (SVM) has better validity and credibility, which could be used as an effective tool to simulate the complicated river system. This finding provides theoretical support and scientific basis for comprehensive improvement and ecological restoration of the Dongting Lake.
区域性应急物资储备级库间的协同选址模型研究
,马祖军
自然灾害学报 , 2012,
Abstract: 鉴于我国应急物资的多部门分散管理与分散储备的特点,研究了区域性应急物资储备体系构建中的应急物资储备级库协同选址问题。为了实现应急物资在不同级库间的协同储备管理与分散优化调拨,建立了应急物资储备级库选址的协同优化模型。用启发式算法通过MATLAB编程来实现,并用算例进行了验证。
三亚旅游文化品牌建设及其可持续发展
,
热带农业科学 , 2010,
Abstract: 在三亚城市文化现有的基础上,分析通过整合三亚各种旅游文化资源,构建三亚文化品牌发展的系统工程,夯实文化品牌市场竞争力,进一步推动三亚城市文化品牌的发展。
气体扩散电极的拓扑网络模型数值研究
Research on Network Structure Model of Gas Diffusion Electrode
 [PDF]

王乾, , , 徐献芝
Applied Physics (APP) , 2012, DOI: 10.12677/APP.2012.24028
Abstract:

本文采用拓扑网络思想,提出了一种简化的气体扩散电极拓扑网络模型,并进行数值模拟计算,得到液体从气体扩散电极一侧渗透到另一侧的液体细观分布图以及液体通过概率与介质亲水性材料比例的关系。结果表明,拓扑网络模型适合描述更细观的渗透问题。
The network topology is adopted in this paper to put forward a kind of simplified model of gas diffusion electrode. Liquid micro distribution map and the relationship between the probability of liquid getting through and hydrophilic property are obtained by numerical modeling calculation. It is revealed that how liquid penetrate medium in the graph. The result shows that the topology of the network model is suitable for describing micro permeation problem.

汉江安康水库流域汛期分期研究
Identification of Flood Seasonality for the Ankang Reservoir Basin
 [PDF]

, 郭生练, 研来, 天元
Journal of Water Resources Research (JWRR) , 2013, DOI: 10.12677/JWRR.2013.21010
Abstract: 合理的汛期分期,可以为汛限水位分期控制提供科学依据和技术支撑,充分利用洪水资源。采用安康水库1943~2011年降雨径流资料,结合天气系统成因分析和数理统计分析等方法,研究确定安康水库的汛期分期方式。结果表明,天气系统成因分析和数理统计分析得到的结果较为一致,分期方式能够较好地反映汉江流域夏秋两汛的特性,安康水库的汛期分期推荐方案为:51~620为前汛期;621~731为夏汛期81~820为过渡期;821~1031为秋汛期
Identification of flood season can provide scientific basis and technical support for multiple control of flood limited water level, and make full use of flood water resources. Using the daily rainfall and runoff data from 1943 to 2011 of the Ankang reservoir basin, the flood seasonality is determined by rational method and statistical analysis methods. The results are consistent and can
两相渗流的拓扑网络模型算法和图形
Numerical Method and Figures Based on the Network Structure Model of Two-Phase Seepage Flow
 [PDF]

, , 王乾, 徐献芝
Advances in Porous Flow (APF) , 2013, DOI: 10.12677/APF.2013.31004
Abstract:

本文探究一种描述多孔介质的方法,将多孔介质的孔隙部分简化为由节点和管道组成的拓扑网络模型,模拟水和空气两相在介质中的渗流过程,得到流动稳定时介质中两相的分布图形,并计算出水能够透过整个介质的概率。


This paper investigates a method to describing the porous medium, which is simplifying the pore part of porous medium into network structure model consist of node and pipeline. We simulate seepage flow of water and air in porous medium through this model, obtain the figures of gas-liquid distribution when steady, and cipher out the probability of that water flows through the whole medium.


胆酸盐对蟾蜍皮肤静息电位的影响
宏钧,
生物化学与生物物理进展 , 1984,
Abstract: 近年来一些学者研究了胆酸盐对各种组织和细胞作用的理化效应。他们特别感兴趣的是这种物质对细胞透性、离子通道的影响,及胆酸盐同细胞膜蛋白之间的相互作用和溶解过程的分子特性。这类研究在理论和实践上都具有广泛意义。例如,将胆酸盐作为一种微扰探针,以获得有关离子通道和膜脂肪成分,即蛋白-脂肪相互作用的信息;或者用于膜蛋白的分级分离制备程序,借以提取某些受体和Na-
胰岛素-牛血清蛋白对蟾蜍跨皮静息电位的效应
宏钧,
生物化学与生物物理进展 , 1985,
Abstract: 近年来一些工作者研究了肽激素对细胞和组织电过程的影响,包括胰岛素对可兴奋细胞和上皮组织静息电位的效应。例如Zierler发现胰岛素能提高鼠骨骼肌的静息膜电位。Lantz等人发现胰岛素对心肌亦有类似作用。deMello和Moore观察到胰岛素引起蛙缝匠肌细胞的超极化,而Rehm等人则检测了蛙的胃粘膜对胰岛素作用的电反应。本文作者以蟾蜍离体皮肤为对象,试图查明胰岛素对上皮细胞的作用,以进一步探究细胞静息电位的变化和膜透性之间的关系。
基于DLT算法的微型无人机(MUAV)视频影像的几何纠正方法
朝奎,
国土资源遥感 , 2006, DOI: 10.6046/gtzyyg.2006.04.06
Abstract: ?高精度真正射影像在灾害监测、紧急救援与反恐决策等应用领域有着广泛的应用前景。利用微型低空无人飞机获取高精度的视频影像流,对影像流进行重采样,借助直接线性变换(DLT)方法,以GPS、INS集成系统获取的摄像机外方位元素为初始值进行内方位元素解算,以此进行视频影像分割后单幅影像的几何纠正,给出了纠正影像的拼接结果。研究表明,在DEM/DSM、DOQQ的精度与视频影像精度匹配条件下,可获得高精度(亚米级)的真正射影像。
油菜半矮秆新种质10D130株高主基因+多基因遗传模型分析
军庆,
植物遗传资源学报 , 2013,
Abstract: 株高是油菜重要的株型改良性状之一。油菜株高对提高油菜的产量、抗倒伏能力和机械收获都有非常重要的作用。本文利用株高性状差异较大的半矮杆新种质10D130和常规品种中双11进行杂交,构建6世代遗传分析群体(P1、F1、P2、B1、B2、F2),以主基因+多基因混合遗传模型对该组合株高进行遗传分析。结果表明:10D130?中双11号组合株高受到1对加性-显性-上位性主基因加性-显性-上位性多基因控制(D模型)。其中,株高性状加性效应值为-8.58,显性效应值为7.44.在B1、B2和F23个分离世代群体中主基因遗传率分别为23.52%、0.91%和17.81%,多基因遗传率分别为30.05%、68.05%和39.35%。10D130半矮杆遗传分析揭示在该材料的运用上不仅要考虑主基因的作用、还要考虑多基因与环境对株高性状的影响。
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