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71.
A lumped water balance model was used to derive a monthly water storage series in the Salado–Juramento southern basin, for the period 1954–1986. The evapotranspiration term was estimated using the Bouchet's complementary relationship. Different evapotranspiration formulas following the concepts of potential evapotranspiration and wet environmental evapotranspiration were used. The regional average groundwater levels and the specific yield were used to tune Bouchet's equation. The extrapolation of the water storage series to a secular period (1901–2002) was achieved using a synthetic annual discharge series. The water storage was deficient for most of the century, i.e. more than 60 years; nevertheless in the last 30 years, the system recovers half of the water previously lost. The singular spectral analysis showed that a significant low‐frequency signal is present in the water storage and precipitation series. The main cause of water storage variability would be given by precipitation, in spite of the vast anthropogenic changes on the basin. Anthropogenic effects would be reflected in the river discharges, where no significant signal is detected before 1970; however, an annual signal is insinuated after that year. The conclusions of this work could be different if we only looked at the 1954–1986 period. The results of that period suggest that the basin is primarily accumulating water instead of being mainly in deficit. Thus, here we demonstrated the importance of the secular analysis to illustrate the complete basin behaviour. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
72.
73.
以江苏宝应生态渔业光伏发电"领跑者"示范基地为研究对象,定量分析了不同辐射指标对渔光互补光伏发电效益的影响机制.结果表明:太阳辐射对渔光互补光伏电站发电效益有着显著影响,且存在季节性波动,在夏秋季日并网峰值及发电量较大,稳定性较高,而冬春季发电效益和稳定性较差;太阳辐射指标与日并网功率最大值相关性较高,且呈明显对数关系,而日发电量与太阳辐射指标呈明显线性关系;不同月份并网功率最大值和发电量与平均辐照度、最大辐照度和累计辐照量均呈正相关关系,影响月并网功率峰值最为明显的是最大辐照度,而影响月发电量最为明显的指标是有效利用小时数.通过研究发现,在该地区开展光伏发电功率预测和前期太阳能资源开发利用评估时,可采用平均辐照度、最大辐照度、日累计辐照量3个指标作为参考指标.  相似文献   
74.
路径分析是嵌入式导航终端的基本功能。在层次空间数据模型的基础上,本文提出了互补分级数据模型,将整个路网拓扑分为概括拓扑和辅助拓扑两级,并给出两级路网拓扑数据快速合并机制形成详细路网拓扑,使得嵌入式硬件平台上远距离路径分析效率更高。  相似文献   
75.
Data from 753 earthquakes are used to determine a relationship between surface-wave magnitude (M s) and bodywave magnitude (m b), and from 541 earthquakes to determine a relationship between surface-wave magnitude (M s) and local magnitude (M L) for China and vicinity: M s=0.9883 m b-0.0420, M s=0.9919 M L-0.1773. The relationship of M s versus m b is obtained for 292 events occurred in the Chinese mainland in the time period from 1964 to 1996, 291 events occurred in Taiwan in the time period from 1964 to 1995 and 170 events occurred in the surrounding area. Standard deviation of the fitting is 0.445. Relationship of M s versus M L is obtained for 36 events occurred in the Chinese mainland, 293 events occurred in Taiwan, China and 212 events occurred in the surrounding area. The total amount is 541 events. Standard deviation of the fitting is 0.4673. The uncertainties of the converted M s in different magnitude intervals can be estimated using complementary cumulative distribution function (CCDF). In the relationship of M s versus m b, taking ±0.25 as a range of uncertainties, in magnitude interval m b 4.0–4.9, the probabilities for the converted M s taken value less than (M s-0.25) and more than (M s+0.25) are 17% and 27% respectively. Similarly, we have probabilities for m b 5.0–5.9 are 34% and 20% and that for m b 6.0–6.9 are 11% and 47%. In the relationship of M s versus M L, if the range of uncertainties is still taken as ±0.25, the corresponding probabilities for magnitude interval M L 4.0–4.9 are 22% and 38%, for M L 5.0–5.9 are 20% and 15% and for magnitude interval M L 6.0–6.9, are 15% and 29%, respectively. The relationships developed in this paper can be used for the conversion of one magnitude scale into another magnitude scales conveniently. The estimation of uncertainties described in this paper is more accurate and more objective than the usual estimation expressed by deviation. The estimations described in this paper indicate various dispersions in different magnitude intervals of original data. The estimations of uncertainties described by probabilities can be well connected with the total estimations of uncertainties in seismic hazard assessment.  相似文献   
76.
在老矿区勘探时,针对新布置的钻孔大多数是两老孔中间的加密孔或后排孔这一特点,给出了新布置钻孔轴线的设计方法以及采取的造斜、纠斜技术措施,取得了较好的效果。  相似文献   
77.
对弹性地基上不同刚度的基础板,利用弹性地基上梁的计算方法进行了不同集中荷载工况下的变形计算。根据计算结果,分析了基础刚度对于弹性地基上基础的最大沉降的影响以及刚度对于基础整体变形的影响。  相似文献   
78.
本文推广地定义了一个新的鞅空间aΣp,通过对它的讨论,建立了它与Herz在[1]中所给鞅空间aLp的等价关系,并将这种讨论扩充到限制增长的Young凸函数场合。此外,还给出了其它平行鞅空间的一些结果。  相似文献   
79.
中国海域大地水准面和重力异常的确定   总被引:12,自引:1,他引:12  
从莫洛金斯基(Molodensky)等1960年给出的由垂线偏差计算大地水准面空域积分公式出发,导出了其相应谱域1维严密卷积和2维球面及平面卷积公式。由Topex/Poseidon,ERS 1/2及Geosat/GM,ERM测高资料求解的垂线偏差计算了我国海域及其邻区大地水准面,其中计算格网为2.5′×2.5′。为了检核,将测高垂线偏差由逆维宁 迈尼兹(Vening Meinesz)公式反演重力异常,与海上船测重力值进行了外部检核;同时还利用司托克斯(Stokes)公式,由上述反演的重力异常计算大地水准面高,与莫洛金斯基公式直接解得的相应结果进行比较作为内部检核。前者的中误差为±9mGal(1Gal=1cm/s2),后者为±0.025m。本文在积分计算中充分应用了2维平面坐标形式和1维卷积严格公式,并做了比较和自校核。  相似文献   
80.
陶赖昭松花江特大桥挠度测量分析   总被引:2,自引:1,他引:2  
分析了陶赖昭松花江特大桥挠度测量结果。利用QY倾角仪对该桥第六跨和第十跨进行了9组静挠度和36组动挠度的实测,并同光电桥梁挠度检测仪的测量结果进行了比较。对比结果表明利用倾角仪测量桥梁挠度的结果是可靠的,精度是有保证的。  相似文献   
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