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361.
Evapotranspiration is one of the key components of hydrological processes. Assessing the impact of climate factors on evapotranspiration is helpful in understanding the impact of climate change on hydrological processes. In this paper, based on the daily meteorological data from 1960 to 2007 within and around the Aksu River Basin, reference evapotranspiration (RET) was estimated with the FAO Penman-Monteith method. The temporal and spatial variations of RET were analyzed by using ARCGIS and Mann-Kendall met...  相似文献   
362.
??????????????????λ?????????????????????????????????????л????????????£????????????????????????????????????λ????????????Ч?????????????????????????????????????????????????λ?????????????PPP???????涯?PPP??????????????????????????????????????λ????????  相似文献   
363.
Currently,with the fast development of GPS technique,GPS RTK is rapidly being applied to the cadastral survey.GPS RTK technique not only improves efficiency and accelerates the rate of mapping,but also increases economic efficiency.The authors introduced a method for GPS RTK rapid positioning,which uses continuous operational reference system (CORS) as a base station to change the method of previous map drawing by obtaining real-time three-dimensional coordinates of boundary points and statistically analyzing with the three-dimensional coordinates obtained by Total Station to get the accuracy of GPS RTK real-time coordinates.The application of GPS RTK in practical measurement was discussed when the data link had been lost especially.The results show that the three-dimensional coordinates measured by total station can be replaced by real-time three-dimensional coordinates measured by Engineering Star RTK in the CORS.  相似文献   
364.
基于贵州省黔东南地区1961―2008年1―12月16个台站冰雹观测资料,引入了表征冰雹事件时间分配特征新参数——冰雹事件集中度和集中期,对黔东南地区冰雹事件年内非均匀性特征进行分析。结果表明:黔东南地区冰雹事件集中度及集中期的平均和异常空间分布均存在很大区域差异,异常空间分布根据地形可分为4个区;从时间演变上看,各区年内冰雹事件集中度与集中期均表现出显著的年代振荡特征,各区年代际变化特征不一致;黔东南区域年内冰雹事件集中度和集中期表现出反向变化趋势。  相似文献   
365.
近46年中国冬季日均气温及极端温度的变化   总被引:1,自引:1,他引:0  
应用1961—2006年我国599个站的冬季逐日平均温度资料,分析了冬季各月最低(高)日均温度、低温日数及三种极端温度指数的变化趋势。结果表明冬季各月最低、最高温度的变化均呈明显上升趋势,2月份升温最显著,日均气温低于5℃的冷日数和日均气温低于-10℃的严寒日数在冬季各月都是减少的。全国近46年冬季极端低温日数呈明显减少的趋势,1986年出现一次跃变,2006年最少;极端高温日数普遍增加,1995年出现跃变,1998年达到峰值;霜冻日数在27°N-46°N间区域显著减少,跃变点在1987年,最低值出现在1998年。  相似文献   
366.
对泰安台不同类型钻孔应变仪的产出资料进行研究,分析分量应变仪的自检可靠性及其与体应变资料的相关性,以及在抽水干扰情况下的相关性。RZB-3仪两组互相正交的分量应变之和S1+S3、S2+S4的自检相关性达到0.999 9,其与体应变的相关性达到0.998以上。但在抽水干扰情况下,S1+S3、S2+S4自检相关性及与体应变的相关性均较差。  相似文献   
367.
Concentrations of halogens (fluorine, chlorine, bromine and iodine) were determined in six geochemical reference materials (BHVO‐2, GS‐N, JG‐1, JR‐1, JB‐1b, JB‐2). Halogens were first extracted from powdered samples using a pyrohydrolysis technique, then hydrolysis solutions were analysed by ion chromatography for F and Cl and inductively coupled plasma‐mass spectrometry for Br and I. The detection limits in solutions were 100 μg l?1 for both F and Cl and 10 ng l?1 for Br and I. Considering the extraction procedure, performed on a maximum of 500 mg of sample and producing 100 ml of pyrohydrolysis solution, detection limits in rock samples were 20 mg kg?1 for F and Cl and 2 μg kg?1 for Br and I. The mean analytical errors on the studied composition ranges were estimated at 10 mg kg?1 for F and Cl, 100 μg kg?1 for Br and 25 μg kg?1 for I. The concentration values, based on repeated (generally > 10) sample analysis, were in good agreement generally with published values and narrowed the mean dispersion around mean values. Large dispersions are discussed in terms of samples heterogeneity and contaminations during sample preparation. Basaltic RMs were found to be more suitable for studies of halogen compositions than differentiated rock material, especially granites – the powders of which were heterogeneous in halogens at the 500 mg level.  相似文献   
368.
The analysis of granitic pegmatites still remains a challenge because suitable natural reference materials are scarce or not available. Two new reference materials were prepared at the Smithsonian Institution, to provide an avenue to pursue the geochemical analysis of micas and feldspars in granitic pegmatites: STL-1, the Stewart lepidolite (NMNH 174041) and ZA-1, the Zapot amazonite (NMNH 174042). STL-1 was prepared from lepidolite collected from the lithium-rich Stewart pegmatite, San Diego County, California (33°22'52'N, 117°03'41'W). ZA-1 was prepared from an amazonite from the topaz-bearing Zapot pegmatite, Mineral County, Nevada, (38° 41'N, 118 °33'W). The results of this study indicated that STL-1 and ZA-1 are homogeneous and could be used as reference materials that would allow the expansion of calibration curves in XRF analysis up to 16000 μg g−1 for Rb, 2000 μg g−1 for Cs and 100 μg g−1 for Tl. STL-1 and ZA-1 also contain unusually high concentrations of Ga and Tl, and STL-1 of Nb.  相似文献   
369.
根据<国际地层表(2004)>C/P界线的划分方案,兴蒙-吉黑造山带一些已知剖面C/P界线附近的(竹蜓)化石带与我国西南地区的一些典型剖面具有可比性.代表性剖面有吉林省永吉黄榆剖面、吉林省双阳光屁股山剖面、内蒙西乌旗米韩高巧高鲁剖面,这些剖面在C/P界线附近岩石地层学普遍为单一的碳酸岩相.生物地层学表现为以(竹蜓) P. uddeni带或P. borealis带的代表性分子或其主要成员覆盖在Triticites带之上,与贵州罗甸、紫云场、云南安乐、广西宜山等知名剖面均具有一定的相似性.因此,可将P.uddeni带底界作为本区C/P界线.  相似文献   
370.
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