动力数值模式侧边界强迫的改进试验

通过修正嵌套模式侧边界缓冲区温度强迫项的计算方法,使区域气候模式所刻画的温度日变化信息与不同下垫面区域的天气变化规律相符合.进而利用数值模式ASRegCM研究了侧边界缓冲区温度强迫的改进处理对嵌套模式模拟效果的影响,并讨论了其对模拟结果改进的可能机制.数值试验结果表明,该侧边界缓冲区强迫的改进对地面气温和降水距平分布的...     

基于云原生的时空大数据平台设计与实现

作为测绘地理信息工作实现"两支撑、一提升"定位的服务载体、自然资源管理的统一底板、智慧城市的时空基础设施、数字孪生城市的空间数字底盘等,时空大数据平台已成为城市信息化建设不可或缺的内容.时空大数据平台服务领域不断扩大,对其在时空大数据汇聚、融合、管理、共享、分析,以及高可用、高并发、高弹性等方面的要求也不断提升.本文基...     

基于主区形态分析的专题地图自动布局研究

随着专题地图的广泛应用,地图的自动布局与快速输出也受到了更多的关注。作者通过分析总结专题地图的布局原则,归纳了常见的地图布局方式,设计了适用于专题地图快速输出的自动布局过程。本文重点阐述了主区形态分析的过程与方法,包括边界数据的压缩、边界最小外接矩形的计算等。通过反复实验,证明该主区形态分析方法科学有效,得出的布局方式基本合理,有利于专题地图快速输出的实现。     

三峡坝区强降水过程6～12小时综合预报方法

为了满足长江三峡水利枢纽施工需要,开展了三峡坝区降水预报研究。在对三峡坝区强降水过程进行仔细分析的基础上,得出了有关统计规律,应用日本数值降水预报产品、卫星云图、雷达回波资料及天气学经验,逐步形成了一套６￣１２小时强降水过程综合预报方法。１９９９年试用表明,该方法对三峡坝区的强降水过程预报具有一定的实用性。     

长江中游砂山的粒度特征及古气候环境意义

通过对江西梁家渡剖面的野外考察、系统采样和粒度测试,在与中原邙山黄土研究对比的基础上,分析和讨论了长江中游晚更新世风成砂堆积序列(江西梁家渡剖面)的粒度特征;并结合热释光年龄测试数据,按照安芷生等的粒度年龄模式获得相应的年代时间标尺,根据粒度与古气候环境之间的内在联系建立了长江中游地区晚更新世以来的气候环境演化序列;发现长江中游末次冰期以来至少发生过10次暖湿-干冷的气候旋回,其中还记录了发生在约22.0,29.5 ka BP的2次Heinrich事件.     

瞬变电磁勘查方法在依力矿区中的应用

依力矿区以往勘查资料很少,通过瞬变电磁测深方法勘查确定的断层,与钻探资料确定的断层,在位置基本上吻合,但方向上有一定的差异。只有物探与钻探相结合,才能使勘查成果质量有很大提高。     

The crust and upper mantle discontinuity structure beneath Alaska inferred from receiver functions

In this study, three receiver function stacking methods are used to study the detailed crust and upper mantle structure beneath south-central Alaska. We used teleseismic waveform data recorded by 36 stations in the Broadband Experiment Across the Alaska Range (BEAAR) and 4 permanent stations in Alaska. H − κ stacking method using P-to-S converted wave and its multiply reflected waves between the Earth's surface and the Moho discontinuity is adopted to estimate the crustal thickness (H) and average crustal V_P/V_S ratio (κ) in this region. The receiver function results for 24 stations show that the crustal thickness under Alaska ranges from 26.0 to 42.6 km with an average value of 33.8 km, and the V_P/V_S ratio varies from 1.66 to 1.94 with an average value of 1.81 which corresponds to an average Poisson's ratio of 0.277 with a range from 0.216 to 0.320. High Poisson's ratios under some stations are possibly caused by partial melting in the crust and the uppermost mantle. Common converted point (CCP) stacking results of receiver functions along three lines show clear Moho and slab images under this subduction zone. The depths of the slab from our CCP stacking images are consistent with those estimated from the Wadati–Benioff Zone (WBZ). In the area between two stations DH2 (147.8°W, 63.3°N) and DH3 (147.1°W, 63.0°N), a Moho depth offset of about 10 km is found by both the H − κ and CCP stacking techniques. Common depth point (CDP) stacking of receiver functions shows not only the 410-, 520- and 660-km discontinuities, but also significant variations (−30 to 15 km) in the transition zone thickness under the southwest and southeast parts of the study region. The transition zone becomes thinner by 20–30 km, indicating that the temperature there is 150–200 K higher than that of the normal mantle.     

精密单点定位中周跳探测与修复方法研究

分析了Geometr-Free以及Melbourne-Wubbena两种组合的性质,使用多种周跳探测方法对两种组合分别进行周跳的探测,计算了各个频率上发生的周跳大小,实现了周跳的修复.     

The sources,pathway, and preventive measures for fluorosis in Zhijin County,Guizhou, China

The F content of several materials from households of Zhijin County, one of the most severe endemic fluorosis-stricken areas in western Guizhou, was determined using the pyrohydrolysis/fluoride ion-selective electrode method to determine the sources of F and the pathways causing the disease. The average F content of the coal burned is 237 μg/g, the clay used as a binder for fine coal is 2262 μg/g, with 828 μg/g in the mixed coal and clay, while the F content of corn is 1419 μg/g, with 110 μg/g in chilies. The binder clay is found to be the main F source for the endemic fluorosis. Fluorine in the clay not only occurs in apatite and hornblende, but also is associated with illite and mixed-layer clay minerals of smectite and illite. About 80% of the F is released during combustion of the mixture. The F content of corn and chilies is about 1000 and 110 times higher, respectively, than the permitted level of F in foodstuffs according to the Chinese Standard GB 4809-84. Most of the F in corn and chilies probably occurs either in smoke dusts attached to the surface or is adsorbed onto the outer peel, rather than being absorbed by the inner part. Thus, in addition to developing F-sequestration technologies, changing the living habits of the residents in the endemic area, for example, washing corn and chilies before cooking and peeling corn before being pulverized into corn flour, will remove a large proportion of the F, and thus it can play an important role in endemic fluorosis prevention.     

自动观测与人工观测差异的初步分析

利用2001—2005年我国700个地面自动气象站与人工平行观测期间的数据, 对自动与人工观测的气温、气压、相对湿度、地表温度、风速风向、降水量进行了差异分析, 统计了两种观测之间的对比差值、百分误差和风向相符率。 对各要素观测差异在全国的分布特点进行了分析, 并检验了气温自动观测对气温资料连续性的可能影响。 结果表明:自动观测与人工观测各气象要素均存在一定的差异, 但大部分地区各要素的差异都在自动站误差允许范围之内; 造成差异的原因是多方面的, 包括仪器本身存在缺陷及观测方法不一致等。各要素自动观测与人工观测差异在全国的分布特点各不相同, 同一要素在不同的气候背景条件下差异大小不一致; 如果要将人工观测数据与自动观测数据连续使用, 还要检验自动观测与人工观测序列是否有显著性差异, 并进行均一性订正。 自动站的使用对年气温序列有一定影响, 总体差异不显著, 但当自动观测与人工观测气温合并使用时, 应进行均一性检验。