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年径流模拟方法比较研究 Comparison of Simulation Methods for Annual Streamflow  [PDF]
,熊立华
Journal of Water Resources Research (JWRR) , 2013, DOI: 10.12677/jwrr.2013.22017
Abstract: 基于两参数月水量平衡(TPMWB)模型的基本结构框架,本文设计了两种年径流模拟方法(TPMWB-1和TPMWB-2)。TPMWB-1方法以实测月降水量和蒸发量作为输入,通过TPMWB模型首先得到模拟月径流量,然后逐月累加得到模拟年径流量;而TPMWB-2方法以实测年降水量和蒸发量作为TPMWB模型输入,直接得到模拟年径流量。作为比较,多元线性回归(MLR)方法也被用于年径流模拟。在东江、赣江和汉江流域的52个子流域上对3种方法进行了年径流模拟。研究发现,3种方法均取得了令人满意的模拟效果。TPMWB-2方法在年径流模拟中的成功应用表明,TPMWB模型结构也适合直接用于年时间尺度的径流模拟,可在更多湿润或半湿润地区年径流模拟中推广应用。 Based on the structure of two-parameter monthly water balance (TPMWB) model, two annual streamflow simulation methods, which were called as TPMWB-1 and TPMWB-2 respectively, were designed in this paper. For the TPMWB-1, observed monthly precipitation and potential evaportranspiration were taken as the inputs, monthly runoff was firstly simulated by using the TPMWB model, and the annual streamflow was subsequently calculated by the sum of the corresponding simulated monthly runoff. For the TPMWB-2, observed annual precipitation and potential evaportranspiration were taken as the inputs, and annual streamflow was then directly simulated. To provide a comparison with the simulation results of these two methods, the multiple linear regression (MLR) method was also used to estimate the annual streamflow. Finally, 52 sub-catchments in Dongjiang, Ganjiang and Hanjiang River Basins were chosen for comparison analysis of the runoff simulation results of 3 methods. The results show that all methods obtain good simulation results. From the successful application of TPMWB-2 methods it is concluded that the structure of TPMWB model is suitable and recommended to directly simulate the annual runoff in more humid and semi-humid regions.
压握状态下不同结构支架的力学分析
Mechanical Analyses of Stents with Different Structures under Compressing State
 [PDF]

任庆, 秋池
Biophysics (BIPHY) , 2014, DOI: 10.12677/BIPHY.2014.22002
Abstract:

研究不同连接筋结构的血管支架的压握性能及支架在压握状态下的柔顺性性能,为支架的设计、开发及介入治疗提供科学的指导。利用Pro/E三维软件构建三种不同链接筋的支架模型。根据支架连接筋的结构分别称为L-支架、V-支架和S-支架。应用ABAQUS软件模拟3种不同链接筋支架的压握和弯曲过程,并进一步分析3种支架的压握性能和柔顺性。在支架压握过程中,L-支架、V-支架和S-支架的弹性回弹率分别为2.67%、6.00%和11.30%,轴向伸长率分别是1.74%、1.57%和2.61%。3种支架在压握状态下的弯曲过程中,L-支架上的应力峰值最小,3种支架端面中心点的位移分别为0.135 mm、0.578 mm和0.675 mm。结论为:L-支架压握后的回弹率最小,压握效果最好;V-支架的轴向伸长率最小,方便在血管中的运输;S-支架在压握状态下的柔顺性最好,较易送达迂曲的血管。
In order to provide scientific guidance of design and development of stents and interventional treatment, the crimping properties and the flexibilities under crimping of the stents with different structures of connecting ribs were studied in this paper. The models of three different structures of connecting ribs were built by commercial software. L-stent, V-stent and S-stent were defined according to different link structures. Finite element analysis was carried out to analyze the crimping properties of three kinds of stents, and the flexibility under crimping was further researched. In the course of the crimping, the resilient rates of L-stent, V-stent and S-stent were respectively 2.67%, 6.00% and 11.30%, and axial elongations were respectively 1.74%, 1.57% and 2.61%. Under the crimping, the peak stress of L-stent had the minimum distribution compared to the others. Three stents displacements of the center of the end face were respectively 0.135 mm, 0.578 mm and 0.675 mm. In conclusion, L-stent had the best performance of crimping as it’s the minimum resilient rate after crimping; V-stent was suitable for transport in the vessels because it's the minimum axial elongation. S-stent had the best flexibility which was easier to reach tortuous vessels.

变化环境下流域水文模型参数区域化研究现状评述
Review of Regionalized Parameters for Watershed Hydrological Models under Changing Environment
 [PDF]

, 熊立华
Journal of Water Resources Research (JWRR) , 2014, DOI: 10.12677/JWRR.2014.36069
Abstract:
变化环境下的流域水文情势发生了较为显著的改变,水文模型采用历史径流资料进行参数率定已然不太合适。因此,建立流域属性与水文模型参数之间的回归关系就成了参数有效估计的可行途径。本文在分析变化环境下流域水文响应的基础上,对现有流域水文模型参数区域化过程进行归纳,分别从流域物理属性选取、水文模型结构分析、回归模型结构及其参数识别和不确定性分析四个方面对国内外流域水文模型参数区域化的相关研究现状进行总结分析,最后,对流域水文模型参数区域化过程中存在的问题进行讨论。
Since the watershed hydrological regimes under changing environment have been altered signifi-cantly, it is not suitable to calibrate the parameters of hydrological models using historical streamflow records. Therefore, it is practicable to establish the empirical relationships between basin characteristics and model parameters for effective parameter estimation. Based on the analysis of watershed hydrological responses under changing environment, this paper gives the basic outline of currently existing regionalized procedure of model parameters, and then summa-rizes its research status at home and abroad from four aspects respectively: selection of catchment properties, analysis of hydrological model, identification of the regional model structure and its parameters, and uncertainty analysis in the above regionalized procedures. Finally, the issues for regionalized parameters of watershed hydrological models are addressed.
论网络环境对会计假设的影响

财会月刊 , 2006,
Abstract: 本文从会计假设的定义出发,探讨了网络环境对会计假设的影响,指出会计假设本质上是一种理想化、标准化的会计环境,网络技术的应用加速了会计信息的传播,丰富了会计假设的表现形式,但并没有改变会计假设的实质。  【关键词】网络环境会计假设虚拟公司会计假设也称为会计核算的基本前提,是指在特定的经济环境中,根据以往的会计实践和理论,对会计领域中尚未肯定的事项所做出的合乎情理的假定与设想,其本质是一种理想化、标准化的会计环境。从一定意义上讲,会计假设是会计人员在长期工作实践中所得出的一种主观设定、一种规则,只有依据会计假设,才能合理界定会计核算的范围、内容与期间,会计人员才可能确定收集、加工会计信息的程序和方法。因此,会计假设是日常会计核算的必要前提。我国新企业会计准则规定,会计假设包括会计主体假设、持续经营假设、会计分期假设、货币计量假设和权责发生制假设。
写在物理边上

物理 , 2013,
Abstract:
线性大系统基于脉冲型信号的加权闭环迭代学习控制
Pulse Signal-Based Weighting Closed-Loop Iterative Learning Control for Large-Scale Linear Systems
 [PDF]

崔建岭, , 狄东宁,
Computer Science and Application (CSA) , 2012, DOI: 10.12677/CSA.2012.22020
Abstract: 本文针对线性大工业过程的稳态递阶优化控制,当系统存在初始状态漂移时,研究了基于脉冲型信号的加权闭环PD-型迭代学习控制算法,并在Lebesgue-p范数意义下利用推广的Young卷积不等式分析了算法的收敛性。数字仿真表明,引入脉冲型信号的加权PD-型迭代学习控制算法能有效地减小初始状态漂移引起的跟踪误差,并能显著改善系统暂态响应的动态品质,如抑制超调,加快响应速度,缩短过渡时间等,有效的验证了理论分析的正确性。
In this paper, the pulse signal-based closed-loop PD-type iterative learning control algorithms are proposed for steady-state hierarchical optimizing control of large-scale linear industrial processes. The convergence of the updat- ing rules is analyzed in the sense of Lebesgue-p norm by using the generalized Young inequality of convolution integral. Numerical simulations show that the PD-type iterative learning control algorithms presented by a pulse signal may ef- fectively suppress the tracking error caused by the initial state shifts and simultaneously can significantly improve the transient performance of the system such as with no or less overshooting, quick transient response, short setting time and so on. Furthermore, it exhibits the validity of the theoretical analysis.
PI3K/AKT/mTOR信号传导通路在姜黄素抑制人肝癌细胞Cox-2表达中的作用
,孙军
解放军医学杂志 , 2014,
Abstract: 目的 探讨MAPK和PI3K信号传导通路在姜黄素调节的环氧合酶2(Cox-2)表达中的作用。方法 分别加入25、50μmol/LLY294002,10、20μmol/LU0126,5、10ng/ml西罗莫司(雷帕霉素,rapamycin)处理人肝癌细胞BEL7402,30min后加入10μmol/L姜黄素,对照组单独加入0、10μmol/L姜黄素,培养6h后,采用RT-PCR和Westernblotting方法检测BEL-7402细胞中Cox-2mRNA和蛋白的表达。以不同浓度(0、2.5、5、10、15、20μmol/L)姜黄素或25μmol/LLY294002处理BEL-7402细胞,培养6h后,采用Westernblotting检测总AKT蛋白和磷酸化AKT蛋白的表达;以不同浓度(0、2.5、5、10、15、20μmol/L)姜黄素或10μmol/LU0126处理BEL-7402细胞,培养6h后,采用Westernblotting检测总ERK蛋白和磷酸化ERK蛋白的表达。结果 与仅加入10μmol/L姜黄素的BEL-7402细胞比较,分别加入25、50μmol/LLY294002,5、10ng/ml西罗莫司后,BEL-7402细胞中的Cox-2mRNA和蛋白表达均明显降低,差异有统计学意义(P<0.01),而加入10、20μmol/LU0126后表达无明显变化(P>0.05)。采用不同浓度姜黄素或25μmol/LLY294002处理后,BEL-7402细胞磷酸化AKT蛋白表达逐渐降低,与对照组相比差异有统计学意义(P<0.01),但总AKT蛋白表达与对照组相比无明显变化(P>0.05)。不同浓度姜黄素或10μmol/LU0126处理后,BEL-7402细胞磷酸化ERK蛋白和总ERK蛋白表达与对照组相比均无明显变化(P>0.05)。结论 姜黄素可能通过PI3K/AKT/mTOR信号传导通路抑制人肝癌细胞BEL-7402中Cox-2的表达。
基于交叉点温度法的煤自燃临界温度测试方法

煤炭工程 , 2011,
Abstract: 为了快速测试煤的临界温度做好煤矿防灭火的指导工作,提出了一种基于交叉点温度测试的煤自燃临界温度测试新方法。实验采用中国矿业大学自主研制的煤氧化模拟实验系统,对精选的典型煤样进行测试,结果表明基于交叉点温度测试得到的临界温度与绝热氧化法所测结果基本一致,且实验周期短,单个煤样测试时间在不超过四个小时,证明利用交叉点温度测试获取煤自燃临界温度是一种可行的、快捷的方法。
预算松弛:基于预算目标的动态博弈
爱民,
财会月刊 , 2011,
Abstract: 预算目标的确定过程是预算各方讨价还价的利益博弈过程,预算目标的结果是预算各方博弈均衡的结果。本文通过剖析预算目标的动态博弈过程,发现信息不对称是预算松弛产生的根本原因,而博弈过程中各方压力的大小也影响预算目标的确定。【关键词】预算松弛预算目标信息不对称动态博弈伴随着预算管理在企业界的推广,关于预算管理的争议也越来越激烈,其中最为突出的一个问题就是预算松弛。预算松弛是指在完成某项预算任务时,有意低估收入或生产能力、高估成本或所需资源。预算松弛是功能的异化,它会扭曲企业资源的配置,增加企业的内部成本,降低企业的经营效率,同时也会滋生员工不诚实的行为习惯,破坏组织内部的诚信基础,威胁企业的长远发展。因此,预算松弛是一个亟待解决的问题,有效治理预算松弛问题的前提是正确的认识预算松弛产生的原因。本文认为由于预算松弛产生于预算管理过程,因此,要了解预算松弛的真正成因就必须剖析预算管理过程。
最大净收益目标下工程项目工期、费用、质量的综合优化模型
爱民,
财会月刊 , 2012,
Abstract: 工期、费用、质量是工程项目管理的三大控制目标,现有研究存在以下不足:工期、费用、质量权重的确定带有主观性或者试图割裂各目标之间的内在联系,且只从成本的角度静态优化,忽略了收益和资金时间价值的影响。以最大净收益为优化目标,在考虑资金时间价值、工程款支付方式、间接费用、业主奖罚金等因素的基础上建立的“工期费用质量综合优化”模型则克服了上述不足,笔者通过算例证明了模型的有效性。【关键词】最大净收益工期费用质量综合优化资金时间价值质量的经济性工期、费用、质量是工程项目管理的三大控制目标,它们之间存在对立统一的辩证关系。项目管理者在处理三者关系时,不能简单“加减”,而要通过目标的反复协调权衡,实现项目目标系统的整体优化。以往文献只对“工期最小”、“费用最低”、“工期费用综合优化”等“一维”、“二维”问题进行定量分析,少有学者涉及“工期费用质量综合优化”领域。直到近年,该领域的问题才渐渐得到学者们的重视,并取得了一些研究成果。目前,解决该问题的思路主要有两种:其一,在“三维”领域利用多属性效应函数或多目标规划法建立模型;其二,利用“降低维度”的方法将“三维”问题转化为“二维”问题。采用“三维”建模法需要对工期、费用、质量之间的重要程度进行主观的权衡,会使决策结果因人而异,波动性较大,而“降低维度”法则会割裂目标之间的内在联系。
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