RAPID WATER TABLE RISE1

ABSTRACT: There are unpublished reports of rapid and large rises in the water table which are out of proportion to the infiltrated volumes of water. The phenomenon seems to result from the conversion of a tension saturated zone to phreatic water by one of several mechanisms. The effect could be triggered when the tension saturated zone intersects: the ground surface, a saturated soil horizon, or a coarse zone. The phenomenon could prove to be a common link in explaining several seemingly diverse phenomena which characterize non-Hortonian runoff in a humid environment. Under certain conditions storm peaks are dominated by flow from small, restricted, “variable source” areas that contributed runoff when saturated from below by rising water tables; for other streams, ground water input forms the major part of the flood peak. The explanation for these observations could lie in an understanding of the rapid water table rise phenomenon. Such a mechanism. if widespread, would provide the means for producing saturation at or near the surface shortly after rainfall commences. The phenomenon should be documented and closely analyzed from a number of perspectives to define its true role in the hydrology of humid environments.     

实验室开展内部审核工作的研究

随着中国经济的发展,无论是政府部门、科研机构,还是社会公众都对实验室的能力更为关注,实验室需要通过外部机构的评审,赢得外界对自身能力的信任,提高实验室的知名度.实验室计量认证工作,一般是按照《实验室资质认定评审准则》的要求,建立并运行质量管理体系.内部审核(以下,简称“内审”)是质量管理体系运行中必须进行的一项质量管理活动,内审是保证质量管理体系有效运行的重要手段.文章对内审各个环节中存在的一些问题进行了分析,提出了改进的建议和应注意的事项,对有效开展实验室内审有一定的借鉴意义.     

基于生态足迹模型的土地利用生态环境分析方法研究

随着经济和社会的发展,生态环境问题正日益受到各国政府和社会的关注。而作为人类一切活动载体的土地,其生态环境显得愈加重要。生态足迹法是一种定量度量生态经济发展协调状况及发展能力的有效方法。本文是基于Bicknell的投入产出模型探讨了对土地利用生态环境进行动态分析的方法,进一步研究了一定区域在进行对外贸易时,对土地资源的开发利用和消费,为衡量土地生态环境和可持续发展状况,作出科学的决策提供定量工具。并从土地利用角度出发,提出了减少生态赤字一些对策。     

关于银行存款余额调节表的编制方法的见解

本文指出了现行银行存款余额调节表编制方法存在的问题,明确提出了银行存款余额调节表的编制方法的理论依据,建立了完整的银行存款余额调节表的编制方法体系。     

土石坝高聚物防渗墙离心机振动台模型试验研究∗

为研究高聚物防渗墙的抗震性能,开展了土石坝高聚物防渗墙和混凝土防渗墙离心机振动台模型试验研究。在调幅分别为0.2g和0.4g El-Centro地震波输入条件下,通过对墙体动应力、超孔隙水压力、动土压力、坝体加速度、坝顶沉降等数据的采集分析以及试验后的开挖验证,结果发现:强震下高聚物防渗墙的动应力远小于混凝土防渗墙,与坝体加速度响应较为一致,但对动力的传递作用使得下游坝坡承受较大的水平土压力作用。研究表明高聚物防渗墙具有较好的变形协调性及良好的抗震性能,但选用高聚物防渗墙的土石坝应注意下游坝坡的加固处理。     

上海市民用建筑能耗的估算与分析

建筑能耗是重要的社会能源消耗主体。采用宏观能源统计方法,利用综合能源平衡表估算上海市1999-2009年住宅能耗和公共建筑运行能耗的变化及其特征。结果表明,上海市民用建筑总能耗由1999年的687.82万tce增加到2009年的1 774.91万tce,平均年增长率为4.68%;住宅建筑能耗呈上升趋势,而单位面积能耗逐年下降,单位面积住宅建筑能耗均值比公共建筑低35.30 kgce/(m2.a);公共建筑单位建筑面积能耗变化呈略增态势,2009年单位建筑能耗比1999年高9.64 kgce/(m2.a)。研究结果可为建筑节能减排政策的制定提供决策参考和数据支持。     

Shake table study of annular baffles in steel storage tanks as sloshing dependent variable dampers

Aboveground steel storage tanks are widely utilized in industrial areas such as oil refineries, petrochemical complexes, oil depots, and etc. Assurance of these infrastructure facilities in high seismic areas is a very important engineering consideration. High amplitude fluid sloshing is one of the widespread causes of steel oil storage tanks during strong earthquakes addressed as an important failure mode. This phenomenon generates additional forces impacting the wall and roof of the tanks. Annular baffles can be used as slosh damping devises to control liquid sloshing within a tank. The main objective of this paper is experimental study of annular baffle effects as anti-sloshing damping devices to reduce fluid wave sloshing height in steel storage tanks typically used in oil and petrochemical complexes during an earthquake. Shake table tests have been used on a reduced scale model steel storage tank in two cases of with and without annular baffles. Three real earthquake ground motion records are used as input base motion. Based on the experimental test results, dynamic characteristics of studied tank models with different filling levels and different baffle dimensions and arrangements have been obtained and summarized in this paper. Also, sloshing heights and convective mode damping values are determined from the test results and compared with API650 code recommendations and recommended equations by other researchers. Generally, the results of this study indicate significant effects of the annular baffles in reducing the fluid wave sloshing height as sloshing dependent variable dampers.     

ARTIFICIAL NEURAL NETWORKS FOR SUBSURFACE DRAINAGE AND SUBIRRIGATION SYSTEMS IN ONTARIO,CANADA1

ABSTRACT: Artificial neural network (ANN) models were developed to simulate fluctuations in midspan water table depths (WTD) given rainfall, potential evapotranspiration, and irrigation inputs on a Brookston clay loam in Woodslee, Ontario, having a dual‐purpose subsurface drainage/subirrigation setup. Water table depths and meteorologic data collected at this site from 1992 to 1994 and from 1996 to 1997 were used to train the ANNs. The ANNs were then used for real‐time control and time series simulations. The lowest root mean squared errors (RMSE) for the various ANNs were 60.6 mm for real‐time control simulation, and 88.4 mm for time‐series simulation of water table depths. It was possible to simulate WTD for the different modes of water table management in one network by incorporating an indicator for switching from one to the other. The ANN simulations were quite good even though the training data sets had irregular measurement intervals. With fewer input parameters and small network structures, ANNs still provided accurate results and required little time for training and execution. ANNs are therefore easier and faster to develop and run than conventional models and can contribute to the proper management of subsurface drainage and subirrigation systems.     

中国安全减灾的未来方略设计——兼论重组安全减灾科学技术学科体系

基于对 2 0世纪中国灾害事故规律的认识及对新世纪灾害态势的分析 ,从科学与文化交叉的新视角 ,研究了以管理、科技、文化、学科建设等为主题的新世纪方略。     

三峡水库中下游水体氮磷时空变化与机制分析

2010年每月定期测定了位于三峡水库中下游的云阳、巫山、秭归和三斗坪段的TN、NH4 N、NO3 N和TP浓度。结果表明：4个段面水质中的TN、NH4 N、NO3 N和TP浓度空间差异不显著,但季节变化显著,TN和TP的季节变化呈单峰格局,分别在5月和7月达到最大值;NH4 N的季节变化则呈双峰格局,主要的峰值出现在7、8月,次要的峰值出现在3、4月。4个地点低水位期（3~8月）的TN、NH4 N、NO3 N和TP浓度都高于高水位期（9月~次年2月）。主要因为在低水位期,长江上游和三峡库区的降雨量大,入库流量显著增加,污染物主要来自长江上游入库的非点源污染和水库两岸农田施用农药化肥造成的面源污染。三峡水库三期蓄水后,水库水质与前两期蓄水后的水质变化不大,水质仍然保持良好,高水位期为Ⅲ类水质,低水位期为Ⅳ类水质