利用GRACE重力卫星反演2003~2013年新疆天山地区陆地水储量时空变化

利用2003-1~2013-12的GRACE月重力场数据来计算新疆天山地区陆地水储量的变化,采用去相关滤波和300 km高斯滤波相结合的方法来滤除GRACE数据中的噪声,同时采用尺度因子的方法来减小GRACE后处理误差的影响,并利用Paulson模型结果来扣除由冰川均衡调整（GIA）对水储量反演结果的影响,把得到的最终结果与同期GLDAS、CPC水文模型进行了验证分析。结果表明,GRACE反演结果与两个水文模型的模拟结果变化趋势基本一致,在2003~2013年间,研究区域的水储量整体上呈现下降趋势,速率为-0.54±0.27 mm/a左右,但期间水储量变化波动较大,在2008年10月份左右,该区域水储量较同期呈现明显减小,这与该时段的干旱事件相一致。     

基于卷积运算的影像镶嵌算法研究

本文将距离加权运算运用到卷积运算上提出了改进的图像镶嵌算法。该算法针对重叠区域图像边缘灰度之间的差异,考虑到中心像元与周围像元之间的相关关系,即临近像元效应,因而需要采用一定的方法来消除或减小这种影响效应,基于空间分析方法给出了像元权重因子的求解,确定出了周围像元对中心像元灰度的影响。之后运用此权重因子采用卷积距离加权算法实现了影像的无缝镶嵌。文中最后对算法在时间和视觉效果上做出了一定的评价。经与其他3种镶嵌算法分析对比,该算法简单易行、耗时少、效率高,达到了良好的视觉效果。     

用切贝雪夫多项式拟合GPS卫星精密坐标

在GPS观测值仿真、单点定位和相对定位中,都需要不断计算GPS卫星的坐标。通过实例对切贝雪夫多项式拟合GPS精密坐标的精度进行分析,并探讨拟合多项式阶数对拟合精度的影响。     

自然灾害研究项目取得的一些重要成果

引言自然灾害随时都会发生。这些灾害包括 :洪水、滑坡、火山、地震和森林火灾。每年数百万欧洲居民面临着自然灾害及其带来的可怕后果。欧洲委员会在自然灾害方面的研究是以揭开灾害涉及的过程、全面的灾害评估、灾害预报和减轻灾害、灾害管理为整体目标进行的。目前 ,有大约 3 5个研究项目在大约 40 0 0万欧洲货币单位的整体预算的资助下进行。这些项目最近一些重要的研究结果总结如下。总体来说 ,许多成果反映科学成就为决策和有效的管理提供有用信息是值得的。1　洪水由于人类活动带来的后果和环境的改变 ,最近数十年在欧洲与洪水有关的…     

紫台多波段耀斑光谱观测

我们用紫台多波段太阳光谱仪进行耀斑光谱观测。这架仪器能在Hα、D、M_g、H_β、H_γ、H、H_δ——K、H_θ——H_(12)和H_(13)——H∞等九个波段基本上同时拍摄耀斑光谱。太阳像直径为11.2厘米,二级光谱的实测分辨率约10万,线色散度约为1毫米/埃。在这次峰年期间,从1980年2月至1981年5月,我们一共拍到16套耀斑光谱底片。我们已开始用这些资料来研究,(1)耀斑的能量传输机制,(2)耀斑的热动平衡偏离,(3)地面与空间观测资料的配合,(4)形态研究,并已开始归算处理这些资料。     

A Study of the Impacts of the Spatial Differences in Climate Engineering Programs on the Extreme Intensities of High-Temperature Events in China Under A 1.5°C Temperature Control Target

Based on the daily maximum temperature data and average temperature data prediction for the period ranging from 2020 to 2099 under the scenario of BNU-ESM climate engineering (G4 test) and non-climate engineering (RCP4.5), the regional differences in the extreme high-temperature intensities in China during the implementation of climate engineering programs (2020 to 2069) and after the implementation of those programs (2070 to 2099) were analyzed using a Weibull Distribution Theory. The results indicated the following: (1) The results of this study’s comparison between the two scenarios had shown that climate engineering had not fundamentally changed the spatial features of the high and low differentiations for the extreme high-temperature intensities with the different recurrence periods in China. It was found that in both scenarios, the extreme high-temperature intensities were characterized by the spatial differentiations of low-temperature intensities on the Qinghai-Tibet Plateau, and high-temperature intensities in the eastern and northwestern region; (2) This study’s comparison results of the two scenarios had indicated that the climate engineering processes during the two study periods could potentially help mitigate the extreme high-temperature intensities with different recurrence periods in China. Furthermore, the mitigation effects during the implementation period would be significantly higher than those after the implementation; (3) This study’s results of the comparison between the periods ranging from 2020 to 2069 and 2070 to 2099 under the proposed climate engineering scenarios suggested that there would be no strong rebounding of the extreme high-temperatures following the implementation of climate engineering programs, and the mitigation effects on the extreme high-temperature intensities during the implementation of the climate engineering programs would be significantly higher than after the implementation of the programs; (4) When comparisons were made of the changes of the average temperatures in China before and after the implementation of climate engineering programs, the results had shown that the average temperature in China had been reduced by at least 1.25℃ as a result of climate engineering, which would effectively alleviate the global warming trend, and could also be conducive to the realization of a temperature control target of 1.5℃ in accordance with the Paris Agreement.     

氩的中子活化分析用于测定矿物、岩石的钾-氩年龄

测定含钾矿物或岩石的钾-氩地质年龄,要求精确分析样品的放射成因Ar^40的含量。目前广泛应用的是体积法和同位素稀释法。前者用麦氏压力计测定自样品析出的氩的总量,然后根据氩的同位素分析数据,扣除混入的非放射成因氩;后者采用稳定同位素稀释     

铜、铅、锌等硫化物单矿物提纯方法

某地多金属矿床中伴生稀散元素赋存规律的研究,需要黄铜矿、黄铁矿、闪锌矿、方铅矿、绿泥石等五种单矿物共21件,计154.9克。要求较快的时间提出化验数据。对此种细粒多金属硫化物的挑选,目前国内都用双目镜或浮选方法。而浮选法达不到     

A STUDY ON NO AND NO_2 ABSORPTION PROPERTIES BY USING LINE-TUNABLE CO LASER

The absorption properties of NO in 5.2 μm band and NO2 in 6.2 μm band are measured for some definite wavelengths by using line-tunable CO laser and long-path absorption cell. The absorption coefficients for 49 CO laser wavelengths are given and variations of absorption withpartial and total pressures are analysed. Furthermore, the experimental errors and the interference of water vapour with the absorption at definite laser lines are also discussed.