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Search Results: 1 - 10 of 252738 matches for " 李雨 "
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1956~2013年汉江流域降雨和气温变化特性分析
The Characteristic Analysis of Rainfall and Temperature between 1956 and 2013 in the Hanjiang River Basin
 [PDF]

, 王雪, 张国学
Journal of Water Resources Research (JWRR) , 2015,
Abstract: 本文选择汉江流域18个国家气象站的长序列观测资料,采用数理统计、Mann-Kendall检验和Spearman秩次检验法,分别从降雨和气温两个方面,对跨流域调水环境下汉江流域降雨和气温变化特性进行了分析。研究结果表明:1) 丹江口以下流域的多年面均雨量较丹江口以上流域多了158.7 mm;汉江流域温度在1990年以后均出现了明显的升高。2) 经降雨和气温趋势分析可知,汉江流域的降雨无明显的变化趋势,而气温则有显著的升高趋势。3) 在整个汉江流域的降雨无明显变化,而气温显著升高的情况下,考虑到未来跨流域调水以及工农业用水规模的增加,汉江流域水资源量的供需矛盾将不容乐观。
In order to evaluate the characteristics and change trend of the surface precipitation and temperature in the middle and lower reaches of the Hanjiang River before the working of the middle route of the South-to- North Water Diversion Project, eighteen meteorological stations were selected. Furthermore, mathematical statistics, Mann-Kendall test and Spearman test were used, and two aspects of temperature and runoff were analyzed based on the meteorological data of the selected stations. The results are as follows. 1) The surface precipitation of the upper drainage area of Hanjiang River basin is 158 mm more than that of the lower drainage area; the temperature of the whole basin has been raised since 1990. 2) After trend analysis, it unfolds that the change trends of the rain-time series in this region are not noticeable, but the temperature shows a significant rise. 3) The imbalance between water supply and demand in the lower Hanjiang River basin will be very conspicuous, if there are not any engineering and non-engineering actions to take.
国内交通心理学的研究热点及其演进分析
Analysis of Hot Topics and Evolution Path of Traffic Psychology Research in China
 [PDF]

王栋, 张舒,
Advances in Psychology (AP) , 2019, DOI: 10.12677/AP.2019.93071
Abstract:
为梳理和分析我国交通心理学的研究现状,以中国知网(CNKI)上检索有关“交通心理学”的253篇文献为研究对象,采用CiteSpace软件对该领域的研究热点及其演进规律进行了可视化分析。研究结果显示:1) 我国交通心理学的研究热点主要集中在驾驶员人格特征、心理素质、攻击性行为、驾驶情绪、驾驶风格、驾驶疲劳、驾驶决策、危险知觉、驾驶经验等方面对驾驶安全的影响;2) 从研究热点的演进过程来看,我国交通心理学发展迅速,整体呈现出研究对象广泛化、研究方法多元化、研究内容多样化的发展态势。
Aiming to understand the development of traffic psychology in China, this study analyzes the 253 related papers in CNKI database using CiteSpace software and visualizes the research hotspots and their evolution in this field. The results show that: 1) The hotspots mainly focus on the influ-ences of driver’s personality, aggressive driving, driver’s emotion, driving style, driver’s fatigue, hazard perception, driving experience on driving safety. 2) From the perspective of the research hotspots evolution, traffic psychology in China has developed rapidly presenting a good state with diversity in study subjects, contents and methods.

X线治疗条件对患者体表吸收剂量影响
福林,
中国公共卫生 , 1990,
Abstract: ?X线在医学诊断和治疗中的广泛应用,使越来越多的人直接受到人工辐射的照射.1次X线诊断患者受到的局部照射量相当于天然辐射年剂量的1-50倍,X线治疗时受到的剂量更大,1疗程内可高达诊断时的几千倍.
三峡水库提前蓄水方案的优化选择 Optimal Scheme of Early Refill Operation for the Three Gorges Reservoir  [PDF]
,郭生练,天元,周研来
Journal of Water Resources Research (JWRR) , 2013, DOI: 10.12677/jwrr.2013.23023
Abstract: 应用Copula函数构建了联合分布及条件概率分布,通过随机抽样方法模拟得到三峡水库9月份随机入库流量序列。建立了提前蓄水方案优选模型,计算并分析了8月下旬不同来水情景下,三峡水库9月份提前蓄水方案的优化选择。研究结果表明:若8月下旬来水为丰水,则9月下旬起蓄,月底均匀蓄水至166 m,较原设计方案,在不增加防洪风险的前提下,多年平均发电量可增加1.57亿kW h (1.46%),弃水量减小10.72亿m3 (12.89%);若来水为平水,则9月中旬起蓄,月底均匀蓄水至166 m,较原设计方案,在不增加防洪风险的前提下,多年平均发电量可增加3.45亿kW h (3.40%),弃水量减小22.59亿m3 (34.19%);若来水为枯水,通过加强实时监测,则可进一步提前至9月上旬起蓄,月底均匀蓄水至166 m,较原设计方案,在基本不增加防洪风险的前提下,多年平均发电量可增加5.50亿kW h (6.12%),弃水量减小19.18亿m3 (51.89%)。 A joint distribution function and conditional probability distribution of this samples using copula was built and inflow series in September were obtained by stochastic simulation method. Furthermore, a refill operation optimization model of the Three Gorges Reservoir was established in this paper to derive the optimal refill scheme. The results show that the optimal refill scheme depends on the reservoir inflow in late August. In the wet year, refill begins in late September with storage level reaching 166 m on September 30 linearly. Comparing with designed scheme, the scheme can generate extra about 1.57 × 108 kW·h electrical energy (by 1.46%) and save 10.72 × 108 m3 water resources (by 12.89%) annually without increasing the flood control risk; In the normal year, refill begins in middle September with storage level reaching 166 m on September 30 linearly. Comparing with designed scheme, the scheme can generate extra about 3.45 × 108 kW·h electrical energy (by 3.40%) and save 22.59 × 108 m3 water resources (by 34.19%) annually without increasing the flood control risk; In the dry year, refill begins in early September with storage level reaching 166 m on September 30 linearly by strengthening real-time monitoring. Comparing with designed scheme, the scheme can generate extra about 5.50 × 108 kW·h electrical energy (by 6.12%) and save 19.18 × 108 m3 water resources (by 51.89%) annually without increasing the flood control risk.
奇异摄动问题的移动网格算法
The Moving Mesh Algorithm of Singular Perturbation Problem
 [PDF]

林彬, 晓培,
Hans Journal of Data Mining (HJDM) , 2013, DOI: 10.12677/HJDM.2013.32005
Abstract: 我们使用移动网格法求解奇异摄动两点边值问题,首先给出问题的差分格式,然后根据等分布原理选取控制函数,给出算法,最后通过求解奇异摄动问题的两个实例来验证这个方法的准确性和有效性。结果表明:使用移动网格法进行计算,CPU运行时间很短并能根据误差来调节网格的分布。
In the paper, we use moving mesh method for solving singular perturbed two-point boundary value problem, First, the problem is given difference scheme, and then select the control functions and give algorithm, at last two instances are computed to verify the accuracy and effectiveness of this approach. The results show that: when this method was used, CPU run time became very short and the distribution of grid could be adjusted according to errors.
版权制度的困境

比较法研究 , 2006,
Abstract:
司法过程的政治约束——我国基层人民法院审判委员会运行研究??

法学家 , 2015,
Abstract: 我国基层法院的审判委员会制度具有缓解矛盾、遏制腐败、提高办案质量、接近案件真相等功能。审判委员会讨论的案件并不都是重大疑难的案件,有一些仅是审判委员会与法官之间的分权性案件,还有一些属于案清简单但处理起来比较棘手的案件。对多数基层法院人员而言,法官只是一种职业,要求所有法官都是法治的殉道者并不现实。审判委员会在讨论决定案件时,面临着一定的政治约束,考量的因素经常是当事人、媒体、上访、社会稳定等问题;实践中,不少超越法律的判案,具有特定的制度逻辑。在讨论审判委员会组织的改革方向时,将其改组为咨询机构的设想,或许具有可行性。
通讯频道的Shannon容量,图的Ramsey数和Erd?s的一个猜想

科学通报 , 2001,
Abstract: 简要介绍通讯频道的Shannon容量和图的Ramsey数的联系,期望引起通讯理论研究者和图论研究者对问题的关注;讨论了Erd?s的一个与此紧密关联的猜想的研究现状.
中国金融风险预警系统的构建研究——基于K-均值聚类算法和BP神经网络

中央财经大学学报 , 2012,
Abstract: ?本文首先通过研究我国1994~2011年的经济数据,对关系到金融系统稳定的16项经济变量进行主成分分析,进而将所选变量归结为宏观经济、金融体系、对外经贸三个方面。在此基础上运用K-均值聚类算法,把金融系统风险状态分为四类。继而借助BP神经网络建立了我国金融系统风险的预警模型,并通过2011年的数据对我国2012年金融系统运行状况进行了预测。预测结果表明我国2012年处于轻度风险状态,总需求的回落和资产泡沫的收缩将是影响我国金融系统稳定运行的主要问题。最后对我国如何预测并防范金融风险给出了政策建议。
温度、pH对剑状矛蚌滤水率的影响

动物学杂志 , 2011,
Abstract: 测定了剑状矛蚌(Lanceolariagladiola)在不同温度和不同pH条件下的滤水率。结果表明,在不同温度(10~28℃)条件下,剑状矛蚌的滤水率均随温度升高而上升,达到最大值后呈下降趋势,其中滤水率最大值出现在24℃时,大、中、小个体组剑状矛蚌滤水率最大值分别为0.826L/h、0.768L/h和0.653L/h。在同一温度下,个体滤水率随软体部干重的增大而增加。温度、软体部干重、温度与软体部干重的交互作用对剑状矛蚌的滤水率有显著影响(P<0.01)。在不同pH梯度上,剑状矛蚌的滤水率呈一个明显的峰值变化,其峰值出现在pH=8,大、中、小个体组的滤水率分别为0.832L/h、0.604L/h、0.421L/h。在pH6~7之间,中个体组、小个体组个体滤水率呈平缓变化。pH、软体部干重及其交互作用对剑状矛蚌的滤水率均有极显著影响(P<0.01)。
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