排序方式: 共有39条查询结果,搜索用时 31 毫秒
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FDR自动土壤水分数据标定问题及解决方法 总被引:4,自引:0,他引:4
针对目前FDR自动土壤水分数据可用性低的实际情况,本文从FDR自动土壤水分站传感器原理出发,结合数据处理流程与方法对湖南60个站点不同层次的标定参数及部分站点的相关观测数据进行了分析,指出目前田间标定法在自然条件下几乎无法得到覆盖土壤各个湿度区间的均匀样本数据,导致二次标定参数不合理是造成FDR自动土壤水分站数据可用性差的根本原因。二次标定方程参数不合理主要表现为方程斜率过大、过小、负值3种情况,导致观测数据增幅过大、常年不变、与实际土壤湿度变化趋势完全相反等问题。最后针对该问题提出了大样本原状取土,实验室标定的解决方法,并对方法进行了初步验证,结果表明该方法能从源头上有效改善土壤水分站观测数据质量。 相似文献
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基于WEB的ORACLE用户管理和授权管理 总被引:1,自引:0,他引:1
对基于动态WEB技术的三层B/S计算模型和实现技术(CGI技术,IntrnetAPI技术,ASP技术,JAVAApplet以及Plug-in插件技术等)进行了详细的论述和分析,指出了各自的优缺点,并以此为基础提出了在三层B/S结构下,用ASP技术实现ORACLE数据库服务器用户管理和授权管理的思路和方法。 相似文献
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根据尚家油田尚9-4圈闭油气空间分布特征、油气成藏时期与断裂活动时期匹配关系,及原油生物标志化合物特征对比结果证实,尚家油田葡萄花油层原油不是尚家油田扶余、杨大城子油层原油通过断裂垂向运移注入的结果。钻井资料分析证实,尚家油田葡萄花油层的砂体虽然厚度小,但分布范围大,尚家油田葡萄花油层的原油是三肇凹陷青山口组源岩生成的油通过断裂沟通的砂体侧向运移至该区而成藏的。控制尚家油田葡萄花油层原油侧向运移聚集成藏的关键因素是断裂与砂体的组合形式:同向断层与砂体组合有利于油气进行长距离侧向运移;反向断层与砂体组合不利于油气的侧向运移,但利于形成断层遮挡圈闭,使油能够聚集起来。流体势场的空间分布同时控制着尚家油田葡萄花油层原油侧向运移及聚集的部位。 相似文献
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Relationship between the onset date of South China Sea (SCS) summer monsoon and the summer rainfall in Shandong Province was examined by comprehensive analysis to establish a conceptual model of the link. If the summer monsoon occurs earlier, the 500 hPa level would induce the teleconnection of Eurasian pattern in the summer (June-August), which indicates that the western Pacific subtropical high is displaced northward further than usual, the Siberian high is intensified and the Okhotsk low is deepened. Under such circumstance, Shandong, located in the west side of the subtropical high and in front of the mid-Siberia high, would be expected to have a wet summer because it is quite possible for cold and warm air to meet and interact with each other in Shandong. Statistical analysis revealed that the 500 hPa anomalies over Korea and Japan were sensitive to the SCS monsoon onset date and very important to precipitation in Shandong, and that the convective activities over the deep water basin in the SCS in 24-26 pentads significantly influenced the position of the ridge line of the western Pacific subtropical high. These findings yielded better understanding of the causative mechanisms involved in the precipitation generation, so that the knowledge gained can possibly be applied for long-lead forecast. 相似文献
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As a new remote sensing technology, the global navigation satellite system (GNSS) reflection signals can be used to collect the information of ocean surface wind, surface roughness and sea surface height. Ocean altimetry based on GNSS reflection technique is of low cost and it is easy to obtain large amounts of data thanks to the global navigation satellite constellation. We can estimate the sea surface height as well as the position of the specular reflection point. This paper focuses on the study of the algorithm to determine the specular reflection point and altimetry equations to estimate the sea surface height over the reflection region. We derive the error equation of sea surface height based on the error propagation theory. Effects of the Doppler shift and the size of the glistening zone on the altimetry are discussed and analyzed at the same time. Finally, we calculate the sea surface height based on the simulated GNSS data within the whole day and verify the sea surface height errors according to the satellite elevation angles. The results show that the sea surface height can reach the precision of 6 cm for elevation angles of 55° to 90°, and the theoretical error and the calculated error are in good agreement. 相似文献