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911.
Richard Hill‐Rowley Thomas McClain Matthew Malone 《Journal of the American Water Resources Association》2003,39(1):99-111
ABSTRACT: This paper presents a methodology for preparing a static water level map using a sample of water level measurements obtained from the well log records of private wells that are finished in glacial drift. The test was conducted in Tyrone Township, located in east central Michigan. A variety of selection criteria were examined and the resulting maps were compared with a ground truth map that was prepared from water level measurements obtained in the field. The map prepared from a random sample of wells at a density of two points per section best approximates the ground truth map. Using a sample of records from the Michigan Statewide Groundwater Database to create static water levels that are used in community ground water vulnerability analyses will provide a more accurate map than using the complete dataset or other selection criteria based on temporal groupings or seasonality. 相似文献
912.
田静敏 《中国环境管理干部学院学报》2003,13(1):69-72
教育在社会发展中起能动作用,教师的工资结构应符合社会主义市场经济规律和教师工作特点,实行按劳分配原则,除标准工资外,还要建立等级津贴和特殊工资,从而保证教育人才的稳定和提高,提高教育的国际竞争力。 相似文献
913.
914.
结合立体仓库结构特点 ,分析了立体仓库故障机理 ,构建了立体仓库故障自诊断系统的总体框架 ,并在分析研究其数据采集处理系统、实时监测控制系统及自诊断专家系统的基础上 ,运用VisualBasic6 0在Windows系统下 ,实现了立体仓库故障的自诊断功能 相似文献
915.
地震环境下不同重要性建筑的抗震设防水准 总被引:2,自引:0,他引:2
针对我国进行建筑物重要性分类时没有考虑地震环境影响的现实,采用地震危险性分析的方法将我国划分为地震危险性不同的3个区.同时,在采用调整设计基准期来标定建筑的重要性类别的基础上,利用地震动参数的危险性曲线,分析了不同重要性建筑在不同危险性特征分区内、不同设防概率水准(常遇、偶遇、罕遇地震)下的地震动参数(设防烈度、地震影响系数和地震地面运动加速度)的取值,最终证实调整结构的设计基准期并考虑地震环境的影响是标定结构的重要性从而调整设防等级的一种好方法. 相似文献
916.
Burchard H. Heede 《Journal of the American Water Resources Association》1986,22(3):351-357
ABSTRACT: Streams are dynamic systems, so steady state does not exist for any appreciable period of time. Streams in dynamic equilibrium respond quickly to change, regaining a new equilibrium. From the response system it follows that there is a causative reason why a stream meanders or degrades or aggrades its bed. These actions represent adjustment processes. If humans interfere with them, other adjustment processes will be initiated. In contrast, if humans work with the ongoing processes, success will be attainable with less efforts and at a lower cost. Local base level change represents one of the most influential channel changes, especially the lowering of this level. Loss of base level may cause degradation throughout a stream network, because the main stem is the base level for all its tributaries. Often, degradation causes bank instability and lowering of streamside water tables that, in turn, endanger the riparian ecosystem. Judging from check dam systems, a rise of the local base level does not raise the bed throughout a stream or network; instead, aggradation stops at a given distance. Preventing local base level changes of a stream network, therefore, is a cost-effective measure. Examples are presented of treatments causing new critical situations and measures to correct them. 相似文献
917.
航空工业安全评价的理论与实践 总被引:1,自引:0,他引:1
根据航空工业总公司颁发试行的《工厂安全性评价规程》及其在企业的实施结果,阐述了该项工作的理论性和实践性均符合我国航空工业的实际情况。特别在深化改革、扩大开放、推行社会主义市场经济的形势下,安全评价是规范工厂,实现安全工作现代化的良好途径。 相似文献
918.
山东省地下水位下降引发的灾害及减灾对策 总被引:1,自引:0,他引:1
近二十年来山东省经济迅速发展与水资源匮乏的矛盾不断加剧。超量开采地下水导致地下水位持续的急剧下降,其结果引发了地裂缝、地面塌陷、海(咸)水入侵、生态环境恶化等一系列人为自然灾害。本文分析了这些灾害的基本特征并指出解决水资源不足是促进山东省经济持续高速发展并减轻地下水位下降灾害的根本措施。 相似文献
919.
Federal regulations require operators of nuclear and coal-fired power-generating stations to estimate the number of fish impinged on intake screens. During winter months, impingement may range into the hundreds of thousands for certain species, making it impossible to count all intake screens completely. We present graphs for determinig the appropriateoptimal subsample that must be obtained to estimate the total number impinged. Since the number of fish impinged tends to change drastically within a short time period, the subsample size is determined based on the most recent data. This allows for the changing nature of the species-age composition of the impinged fish. These graphs can also be used for subsampling fish catches in an aquatic system when the size of the catch is too large to sample completely. 相似文献
920.
The 2007 edition of the National Fire Protection Association Standard 68 for Explosion Protection by Deflagration Venting has a new provision to account for the turbulence level in combustible dust or powder processing equipment. This paper explains the development of this new provision for increased deflagration vent area requirements in highly turbulent combustible dust/powder processing equipment. The development includes a review of initial turbulence level effects on vented explosion pressures, and a review of turbulence levels measured in ASTM E1226 and ISO 6184/1 explosion test procedures to determine Kst. A review of operating conditions in some representative spray dryer plant equipment suggests that most equipment of this type probably do not have high enough air flows to require increased explosion vent areas due to turbulence, but some types of equipment with high tangential entrance air flows may well need larger vent areas. 相似文献