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101.
杨云  丁蕾  权继梅  崇伟 《气象科技》2017,45(2):209-216
通过对世界辐射基准传递到我国省级工作级标准总辐射表的不确定度进行分析和评估,确定了量值传递过程中不确定度来源主要包括测量重复性、输出电压值、太阳入射角变化、热偏移以及标准器等引入的不确定度,得出我国省级工作级标准总辐射表校准结果的不确定度为0.6%。我国采用"成分和"法对省级太阳总辐射标准量值进行传递,其标准器引入的不确定度系标准直接辐射表(0.3%)和标准散射辐射表(1.0%)的合成,标准器引入的不确定度所占比例达90%以上,因此提高标准直接辐射和标准散射辐射的测量确定度是减小量值传递不确定度的关键。此外太阳辐射量值传递的准确性受天气条件的影响较大,选择天气稳定,大气透明度高的天气以及太阳高度角大于30°的时段;增加测量次数以减小测量数据的分散性,降低重复性测量引入的不确定度;对被校准总辐射表进行通风,以减小热偏移的影响;保证仪器安装水平以及准确跟踪遮光,可以进一步减小量值传递的不确定度,提高我国短波辐射的测量水平。  相似文献   
102.
徐冲  柳林  周素红 《地理科学》2016,36(1):55-62
在无时空考虑的密度估计算法基础上,分别加入了案件点之间的时间临近相似性、空间临近相似性和时空临近相似性的考虑,利用DP半岛2006~2007年的街头抢劫犯罪数据为基础计算无时空临近相似性、时间临近相似性、空间临近相似性和时空临近相似性4种不同算法所得到的犯罪热点图,并以之预测2008年的街头抢劫。通过Natural breaks(Jenks)分级方法和等比例面积选取两种方式来划定热点区域进行预测并进行PAI指数得分比较,结果表明时空临近相似性的密度估计算方法在犯罪预测的优势比较显著。  相似文献   
103.
填海造地项目海域管理和土地管理衔接不充分问题由来已久,已成为海洋管理中的痛点和难点。文章对浙江省在填海造地项目换发土地使用权证书、规划与用途管制、使用金征收等方面的衔接制度和实践经验开展梳理分析、调查研究,剖析存在的问题,提出管理建议。研究表明,填海造地与土地管理衔接的主要问题为:换发土地使用权证书所需土地管理指标配套不足;海域和土地权属价值不一致;规划、用途管制衔接不充分;使用金征收标准不统一。为规范填海造地与土地管理的衔接,提出建议:统筹陆海规划和用途管制;建立填海项目指标(计划)管理制度;探索海域使用权价值实现形式;完善海域和土地使用金衔接制度;推进海域土地使用权联合招拍挂出让。本研究可为相关政策制定提供参考。  相似文献   
104.
本文旨在针对当前海域节约集约利用的要求下,缺乏低效用海客观评价体系的现状。采用层次分析法和德尔菲专家打分法等技术,在DPSIR框架下,从指标选取、权重设立以及综合评价等方面构建低效用海评价指标体系,并在浙江省普陀区进行应用示范。结果显示,普陀区41个填海项目中,有17个项目评价等级为优,有4个评价等级为良好。等级为一般和较差的项目各10个,占评价项目48.7%。这表明普陀区填海项目中批而未填、填而未建或闲置用海情况较为明显。本研究在指标体系构建和实际应用方面具有创新性和先进性,对于低效用海的节约集约利用具有一定的实际意义和应用价值。  相似文献   
105.
Fabry-Perot Interferometer(FPI) has been used widely for wind measurements of the middle and upper atmosphere.To date, most of FPIs have been based on full-closed circular fringe, which needs 15–25 min to obtain a group of wind velocity(zonal and meridional). However, it is hard to improve the temporal resolution because full-closed circular fringe in several directions cannot be easily imaged onto the same Charge-Coupled Device(CCD) with enough airglow intensity. In this paper, a data processing method is proposed for non-full circular fringe of FPI, which can support CCD with enough area of observations in several directions simultaneously. The method is focused on the center determination of non-full fringe. It includes radial cross-section, peak coordinate determination, and center calculation. Based on the calculated center, the fringe is annular summed. Then its radius is determined subsequently using Gaussian fitting. Finally, the wind is retrieved from the fringe radius. For validation, fringes from two ground-based FPIs were used, which are deployed in Kelan(38.71°N, 111.58°E) and Xinglong(40.40°N, 117.59°E) in China. The results retrieved from non-full fringes of FPIs were compared with that from full-closed circular fringe. The averaged wind deviation between them demonstrates reasonable difference with 5.38 ms~-(1) for 892.0 nm airglow emission, 5.81 ms~-(1) for 630.0 nm emission, and 3.03 ms~-(1) for 557.7 nm emission. Besides, wind results of Xinglong FPI are compared roughly with measurements of meteor radar which is deployed in Ming Tombs of Beijing(40.3°N,116.2°E). Good agreement demonstrates that this method is robust enough for FPI wind retrieval of mesosphere and thermosphere.  相似文献   
106.
针对不规则波浪作用下Wigley型船的运动响应问题进行了系统的研究,采用统计学方法深入探讨了船舶不规则运动幅值和响应周期的分布规律,并通过傅里叶变换对船舶运动响应进行了频谱特征分析。结果表明,船舶横摇方向与升沉和纵摇方向随机运动的响应特征有显著差异。在升沉与纵摇方向,波浪谱峰频率远离自振频率,前十分之一大振幅运动对应周期离散性较小,基本稳定在波浪谱峰周期附近,但小振幅运动周期分布离散性较大,频谱分析指出船舶升沉与纵摇运动响应频谱在波浪谱峰频率附近出现明显峰值。而在横摇方向,波浪谱峰频率与自振频率相耦合,不同振幅的横摇运动响应周期均稳定在自振周期附近,且周期离散性较小,频谱分析也表明横摇运动响应频谱主要集中于船舶运动自振频率附近。  相似文献   
107.
In order to analyze 3-dimensional movement and deformation characteristics and seismic risk of the Xianshuihe fault zone, we inverted for dynamic fault locking and slip deficit rate of the fault using the GPS horizontal velocity field of 1999-2007 and 2013-2017 in Sichuan-Yunnan region, and calculated annual vertical change rate to analyze the vertical deformation characteristics of the fault using the cross-fault leveling data during 1980-2017 locating on the Xianshuihe fault. The GPS inversion results indicate that in 1999-2007, the southeastern segment of the fault is tightly locked, the middle segment is less locked, and the northwestern segment is basically in creeping state. In 2013-2017, the southeastern segment of the fault is obviously weekly locked, in which only a patch between Daofu-Bamei is locked, and the northwestern segment is still mostly in creeping state, in which only a patch at southeastern Luhuo is slightly locked from surface to 10km depth. The cross-fault leveling data show that annual vertical change rate of the Zhuwo, Gelou, Xuxu and Goupu sites on the northwestern segment is larger, which means vertical movement is relatively active, and annual vertical change rate of the Longdengba, Laoqianning, and Zheduotang sites on the southeastern segment is small, which means the fault is locked, and the vertical movement changes little before and after the Wenchuan earthquake. Combining with the 3-dimensional movement and deformation, seismic activity and Coulomb stress on the Xianshuihe Fault, we consider the seismic risk of the southeastern segment is larger, and the Wenchuan earthquake reduced the far-field sinistral movement and the fault slip deficit rate, which may reduce the stress and strain accumulation rate and relieve the seismic risk of the southeastern segment.  相似文献   
108.
In this study, a detailed database of landslides triggered by the 25 April 2015 Gorkha (Nepal)MW7.8 earthquake is constructed based on visual interpretation of pre- and post-earthquake high-resolution satellite images and field reconnaissance. Results show the earthquake triggered at least 47 200 landslides, which have a NWW direction spatial distribution, similar with the location and strike of the seismogenic fault. The landslides are of a total area about 110km2 and an oval distribution area about 35 700km2. On the basis of a scale relationship between landslide area (A)and volume (V), V=1.314 7×A1.208 5, the total volume of the coseismic landslides is estimated to be about 9.64×108m3. In the oval landslide distribution area, the landslide number density, area density, and volume density were calculated and the results are 1.32km-2, 0.31%, and 0.027m, respectively. This study provides a detailed and objective inventory of landslides triggered by the Gorkha earthquake, which provides very important and essential basic data for study of mechanics of coseismic landslides, spatial pattern, distribution law, and hazard assessment. In addition, the landslide database related to an individual earthquake also provides an important earthquake case in a subduction zone for studying landslides related to multiple earthquakes from a global perspective.  相似文献   
109.
国家地震应急救援物资综合管理平台建设   总被引:1,自引:0,他引:1  
针对目前中国地震应急救援物资管理中办法互有差异、系统各有不同,信息化和标准化程度较低,难以统计物资储备的现状,且不易在震后应急救援中对物资进行快速合理地调度等问题,提出数据资源化、业务标准化和服务智能化的解决方案,以此研究并建设面向全国各地震应急救援物资管理单位,统一化的服务于地震应急救援保障与决策的物资信息综合管理平台。该平台已在中国地震应急搜救中心上线,运行结果表明,有效提升了地震应急救援物资综合管理、使用和分析的水平,可解决目前存在的问题,对地震应急救援保障与决策具有重要意义。关键词地震应急;应急救援物资;管理平台  相似文献   
110.
The forest canopy affects the water entering the forest ecosystem by intercepting rainfall. This is especially pertinent in forests that depend on rainfall for their ecological water needs, quantifying and simulating interception losses provide critical insights into their ecological hydrological processes. In the semi-arid areas of the Loess Plateau, afforestation has become an effective ecological restoration measure. However, the rainfall interception process of these plantations is still unclear. To quantify and model the canopy interception of these plantations, we conducted a two-year rainfall redistribution measurement experiment in three typical plantations, including a deciduous broadleaf plantation (Robinia pseudoacacia) and two evergreen coniferous plantations (Platycladus orientalis and Pinus tabuliformis). Based on this, the revised Gash model was used to simulate their interception losses, and the model applicability across varying rainfall types was further compared and verified. The experiment clarified the rainfall redistribution in the three plantations, and the proportions of throughfall to gross rainfall in Robinia pseudoacacia, Platycladus orientalis, and Pinus tabuliformis were 84.8%, 70.4%, and 75.6%; corresponding, the stemflow proportions were 2.0%, 2.2%, and 1.8%; the interception losses were 13.2%, 27.4%, and 22.6%, respectively. The dominant rainfall pattern during the experiment was characterized by low-amounts, moderate-intensity, and short-duration, during which the highest interception proportions across the three plantations were observed. We used the Penman-Monteith equation and the regression method, respectively, to estimate the canopy average evaporation rate of the revised Gash model, finding that the latter provides a closer match to the measured cumulative interception (NSE >0.7). When simulating interception under the three rainfall patterns, the model with the regression method better simulated the cumulative interception and event-scale interception for Platycladus orientalis and Pinus tabuliformis plantations under the dominant rainfall pattern. The results contribute valuable information to assess the impact of forest rainfall interception on regional hydrologic processes.  相似文献   
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