采用误差迭代补偿的高精度相位解缠方法

最小二乘相位解缠算法是一种全局算法,快速稳定简单易实现,但该算法未绕过相位不连续区易造成误差的全局扩散,导致结果存在较大误差.针对最小二乘相位解缠算法的缺陷,提出一种高精度相位解缠方法.该方法在基于快速傅里叶变换的最小二乘解缠算法基础上,采用误差迭代补偿技术,补偿解缠误差.仿真和实测相位数据的实验结果表明,该方法可有效提高解缠精度,且在仿真实验的定量分析中得出,在强相位噪声条件下,该方法的解缠精度比最小二乘算法提高一个数量级.     

基于SVG的专题地图与Google地图混搭研究

Google地图开放API后,将Google地图作为地理底图,由用户定制专题要素成为专题地图制作的一种新形式。文中研究如何在Google地图上制作精美生动的网络专题地图。SVG用于表达网络专题要素有其独特的优势,文中结合SVG的优点探讨以Google地图为地理底图的网络专题地图的表达、设计与实现方法,尝试解决网络地理底图与专题要素的一致性表达问题。     

扬子地区典型剖面二叠系不同沉积相地球化学特征

对扬子地区2个典型剖面即四川广元上寺剖面和贵州罗甸纳水剖面二叠系系统采样,在沉积相研究的基础上,对华南二叠系碳酸盐岩地层不同沉积相地球化学特征进行了分析。研究表明:Co、Ba、V、Rb等具有指相意义的元素,在越靠近深水环境,Co、Ba、V、Rb平均丰度越高,而w(Sr)/w(Ba)值从开阔台地相到盆地相整体有降低趋势。贵州罗甸纳水剖面为斜坡沉积背景的典型剖面,从台地前斜坡相→陆棚相→斜坡相→盆地相,w(ΣREE)值逐渐增大,且各相带稀土元素配分模式存在明显的Ce异常。四川广元上寺剖面二叠系浅海陆棚相下部和盆地相地层中平均残余有机碳丰度大于1.5%,说明这2个沉积相带可能为该地区优质烃源岩发育相带,该剖面二叠系显示从开阔台地相到盆地相具有有机质逐渐富集的特点。     

Groundwater discharge to the Changjiang River, China, during the drought season of 2006: effects of the extreme drought and the impoundment of the Three Gorges Dam

Groundwater can play an important role in the compensation of runoff reduction due to extreme climate events such as droughts, as well as in response to anthropogenic actions such as the construction of a dam. The increase in ²²⁶Ra specific activity and the runoff from September to December in 2006 is used to estimate the total discharge of groundwater along the mid-lower reaches of the Changjiang River. The total groundwater discharge was found to account for 31% of the increased discharge between Yichang and Datong. The groundwater discharge to lakes (i.e. Dongting Lake) constituted the major contribution of groundwater discharge to the mid-lower reaches of the Changjiang River. More importantly, the second impounding operation of the Three Gorges Dam from 20 September to 27 October 2006 induced a water level decrease in surrounding lakes and rivers, which led to an additional groundwater discharge of 63.3?×?10⁸?m³, accounting for 85% of the total groundwater discharge in the same period. Taken together, these observations indicate that groundwater discharge along the mid-lower reaches plays an important role in maintaining stream flow in the drought season, especially in extreme drought years or in response to human activities.     

200 hPa高空急流与宁夏春季沙尘暴过程的特征分析

 利用NCAR/NCEP全球再分析资料，首先分析了1955年到2003年宁夏春季沙尘暴过程与200 hPa急流的关系，发现2月、3月200 hPa的U、V风场与宁夏春季沙尘暴关系密切。然后对1970\_1999年66次宁夏强和特强沙尘暴过程发生前200 hPa急流的演变情况进行了分析，结果表明：宁夏强和特强沙尘暴过程发生前后，高空急流主要表现为3种类型：一是西风急流型;二是副热带急流型;三是西风急流与副热带急流振荡合并型。最后以2001年4月8日宁夏特强沙尘暴天气过程为例，对其发生前后高空急流演变与沙尘暴落区、垂直环流特征及其对沙尘暴的作用进行了分析和探讨，得到了一些新的启示。     

阜康绿洲生态系统生物量空间格局分析

 利用阜康绿洲平原地区于2003年8月,在野外实测的53个样方植物的生物量干重数据与同期陆地卫星MODIS影像的第1,2通道250 m遥感数据,通过分析植被指数NDVI与绿洲植被生物量的相关关系,进而建立该遥感植被指数与植被生物量的一元线性和非线性回归模型。研究表明:植被指数NDVI与绿洲生态系统植被生物量之间存在较好的相关性;所建遥感植被指数与绿洲植被生物量的回归模型中,三次方程为所得到的非线性回归模型中最适合用于阜康绿洲生态系统植物生物量和生长的监测;并利用该模型进行分析同年4~9月研究区内植物生物量的时空间分布,并得出阜康绿洲生态系统植物生物量的时空分布特征。总体格局是:绿洲内部农业生态系统的生物量时空特征变化是十分的明显,生物量的增长从5月底至8月;且于7月、8月生物量达到旺盛时期;随后开始呈下降趋势;荒漠植物群落生物量时空特征有一定程度的变化但表现不明显,且荒漠植物生物量的变化在时空上是非同步性。这都是由于在整个生长季节内不同植物群落的生长发育表现不同的时间,和荒漠植物在时间上表现出不同物候导致的。同时分析了绿洲生态系统植物生物量的时空分布特征及相关影响生物量的多种因素。     

新疆塔里木河下游(上段)地区天然草地生态脆弱性研究

塔里木河(以下简称塔河)流域是我国生态脆弱地区之一,其中塔河下游地区为严重脆弱地区。塔河下游地区广大的天然草地主要分布在绿洲-荒漠过渡带,该地带也是一个典型的生态脆弱带。依据有关生态脆弱带评价方法,结合塔河下游天然草地分布的实际状况,建立生态脆弱性评价体系。对垂直于塔河河道不同距离上的草地生态环境进行了分析,得出在距离河道500 m以上的地带草地生态环境表现为中度生态脆弱,<350 m的草地生态环境表现为一般脆弱。评价结果基本符合实际情况,对指导当地合理开发和利用草地资源具有一定的价值。     

The complexity feature of crust-mantle boundary in Zhangbei seismic region and its tectonic implication

The ProP waveform data obtained from a deep seismic sounding profile, which ran through Zhangbei seismic region, were processed by means of both seismic wave complexity coefficient and frequency spectrum analysis methods, and the complexity characteristics of crest-mantle boundary beneath the studied area and its adjacent region were determined. The results show that the place below epicenter can be taken as boundary, the northern side of which is Inner Mongolia axis with small complexity coefficient and the southern side of which is Huai＇an basin with large complexity coefficient. The different spectrum patterns at the two sides of the epicenter were inferred from spectrum analysis. In the epicentral area, there have been multi-period magmatic eruptions since Meso-Cenozoic and craters exist at the surface. From the velocity imaging of middle and upper crust in Zhangbei seismic region it can be found that there are crustal low velocity bodies around the craters and also there are low velocity zones, which went into deep crust. It is suggested that the distinct zones of crust-mantle boundary complexity may be the margin, where the magma had intruded due to magma activity in Meso-Cenozoic. The southern side with large complexity coefficient is deep magmatic activity area and the northern side with small complexity coefficient is stable crust-mantle tectonics. The difference of crust-mantle complexity provides deep background for the development of strong earthquake.     

推覆体下特厚煤层开采的特殊地质灾害问题

新集二矿13-1煤为新生界松散层、推覆体下第一开采的特厚煤层,存在着与推覆体发育有关的隐伏构造裂隙水、离层裂隙水(气)、F02断层活化导水、冲击地压造成导水裂隙扩展等特殊的地质灾害问题。针对这些安全隐患,提出了留设防水煤柱、对离层空间充填注浆、选择合理的开采方案、加强采前探测等措施。