宁镇中段矿化斑岩体的侵位深度及剥蚀程度研究

判别岩体侵位深度对找矿富有指导意义,查明岩体剥蚀程度是评价斑岩铜矿找矿前景的重要因素之一。运用岩体"盖层"厚度恢复法、成岩温度与压力计算法、蚀变矿化分带判别法、岩体的顶垂体、捕虏体、析离体及岩脉发育状况判别法,以及岩石的结构、构造和矿物结构形态判别法,综合研究了宁镇中段主要斑岩体的侵位深度和剥蚀程度,结果表明宁镇中段侵入体总体上具有由西向东、由南向北剥蚀程度逐渐加深的特点。     

利用高光谱数据进行植被生化成分反演方法研究

高光谱数据包含着丰富光谱信息,能够定量地分析物质成分^[1]。由高光谱数据,可以运用多元逐步线性回归方法反演植被生化组分含量,从而达到监测植被生长状况的目的^[2]。本文具体介绍了多元逐步线性回归方法,及其在氮、木质素和纤维素含量估算中的应用。     

相位相关速度分析方法研究及效果比较

利用统计假设原理及地震信号瞬时相位的相关特性,计算了叠加速度谱。理论模型的试算和实际资料的处理结果表明:与常规速度分析方法相比,该方法具有较高的时间分辨率和速度分辨率,而且抗噪性非常好。该方法不仅不受时窗边界奇异性的影响,还可以有效地避免边缘效应,反映更多反射波信息。该方法对于层速度的精确计算很关键,同时也表明了统计方法用在多道信号估计上是有效的。     

最小生成树相位解缠中冗余去除算法

目前，相位解缠的方法中以Goldstein提出的枝切法最为经典，它通过枝切线将残差点相互连接使得残差点电荷中和，在相位展开处理的积分中，积分路径不能穿过分支，从而限制误差的传播。但是由于枝切线连接策略的不合理，往往造成连成的枝切线过多、过长，甚至多条枝切线形成闭合区域，造成不能解缠的“死区”，特别是在残差点较多的情况，这种现象更为严重。本文在最小生成树原理的基础上，提出的枝切线冗余去除算法能简单、准确地去除枝切树中的冗余，并保证了相位解缠具有最好的效果。     

碳水化合物的组合合成

碳水化合物的组合合成是一项新兴技术，该技术可以在短时间内合成大量用于进行生物活性筛选的寡糖及拟糖物。液相与固相合成技术可以极大地加快药物研究与开发进程。作者针对该技术在碳水化合物合成方面的研究进展情况进行讨论。     

Evaluation of change in subsurface thermal environment due to groundwater flow in the Tokyo Lowland,Japan

Information on the distribution of subsurface temperature and hydraulic heads at 24 observation wells in and around the Tokyo Lowland, the eastern part of the Tokyo Metropolitan area, were examined to make clear the relationship between groundwater and the subsurface thermal environment in the urban area. Minimums in temperature–depth logs due to subsurface temperature increasing at shallow parts were recognized in 21 wells. This fact shows subsurface temperature is affected by ground surface warming in almost all of this area. Deeper than minimums, where the effects of surface warming became relatively small, regional variation is observed as follows: high temperatures are shown in the central part to the southern part, and low temperatures shown in the inland to eastern part. The high temperature area corresponds to an area where the lower boundary of groundwater flow is relatively shallow. This area corresponds also to an area with severe land subsidence resulting from excessive groundwater pumping. It is considered that this high temperature area is formed by the effects of upward groundwater flow affected by hydrogeological conditions and pumping. On the other hand, a comparison between past data (1956–1967) and present data (2001–2003) revealed widespread decreasing temperature in the inland area. This is explained by downward groundwater flow based on an analysis of temperature–depth logs. This fact suggests that subsurface temperature is not only increasing from the effects of surface warming but also decreasing from the effects of groundwater environment change due to pumping.     

Velocity structure of uppermost mantle beneath North China from Pn tomography and its implications

20301 Pn arrival time data are collected from the seismological bulletins of both national and regional seismic networks. Pn travel time residuals are tomographically inverted for the Pn velocity structure of uppermost mantle beneath North China. The result indicates that the average Pn velocity in North China is 7.92 km/s, and the velocity varies laterally from ?0.21 to +0.29 km/s around the average. The approximately NNE trending high and low velocity regions arrange alternatively west-eastward. From west to east we can see high velocity in the middle Ordos region, the Shanxi graben low, the Jizhong depression high, the west Shandong uplift and Bohai Sea low, and the high velocity region to the east of the Tanlu fault. In the southern boundary zone of the North China block, except for the high velocity in the Qingling Mountains region, the velocity is generally lower than the average. Obvious velocity anisotropy is seen in the Datong Cenozoic volcanic region, with the fast velocity direction in NNE-SSW. Notable velocity anisotropy is also seen around the Bay of Bohai Sea, and the fast velocity directions seem to show a rotation pattern, possibly indicating a flow-like deformation in the uppermost mantle there. The Pn velocity variations show a reversed correlation with the Earth's heat flow. The low Pn velocity regions generally show high heat flow, e.g., the Shanxi graben and Bohai Sea region. While the high Pn velocity regions usually manifest low heat flow, e.g., the region of Jizhong depression. This indicates that the Pn velocity variation in the study region is mainly aroused by the regional temperature difference in the uppermost mantle. Strong earthquakes in the crust tend to occur in the region with the abnormal low Pn velocity, or in the transition zone between high and low Pn velocity regions. The earthquakes in the low velocity region are shallower, while that in the transition zone are deeper.     

太湖地区气溶胶光学厚度的分布及其在大气校正中的应用

采用太湖地区水面光谱数据以及MODIS遥感影像数据,利用辐射传输模式6S,选择自定义气溶胶类型,反演得到太湖地区气溶胶光学厚度(aerosol optical depth,AOD)分布,将其与太阳光度计CE318实测气溶胶光学厚度分别应用于太湖区域的大气校正中,得到不同的水面反射率,并参考实测水面反射率进行对比分析。结果表明:反演的太湖地区气溶胶光学厚度分布较为合理,造成此分布的原因可能是太湖北岸工业较发达,污染较严重。太湖颗粒物的吸收特性和卫星接收到的表观反射率导致反演数据的差异,是反演气溶胶光学厚度分布不均匀的主要原因。使用MODIS数据反演得到的太湖地区AOD进行大气校正,更加精确。该研究方法和结果可为气溶胶光学厚度反演、精确卫星数据大气校正提供参考。     

多频数据组合在周跳探测和修复上的应用

利用模拟的L5观测数据,结合传统的伪距/载波组合法,对周跳的探测与修复进行了实例计算,并与双频组合观测值的周跳探测方法进行了比较。结果证明,不管对大周跳还是小周跳,该方法均能在单历元间准确地探测出各个频率上发生的周跳,较之双频组合观测值的探测方法具有更大的优越性。     

Application of High Energy Dynamic Compaction in Coastal Reclamation Areas

High energy dynamic compaction (HEDC) is adopted in a coastal reclamation area because the grain size of backfilled soil mostly ranges between 20 cm and 100 cm. The in situ tests for evaluating the effectiveness of HEDC were performed on the backfilled soil ground. The crater depth per drop and the whole test zone elevations before and after HEDC were measured and analyzed. Dynamic penetration tests and spectral analysis of surface wave (SASW) tests were used for investigating the improvement depth. Furthermore, the allowable bearing capacity of HEDC treated ground was determined based on the results of plate-load tests. It was found that HEDC did not cause the ground surface heave during construction, and was more effective than low energy dynamic compaction (LEDC) in terms of applied energy utilization. Based on the test results, the improvement depth of HEDC at this site was not less than 14 m, and there was no obvious weak layer within the range of improvement depth. The allowable bearing capacities were larger than 160 kPa. The investigation results indicate that the HEDC technique is an effective way for improving backfilled coarse-grained soil in coastal reclamation areas. This technique helps to achieve both greater improvement depths and higher ground bearing capacities as compared with LEDC.