Budd—Chiari综合征的CT评价

回顾性分析了５２例Ｂｕｄｄ－Ｃｈｉａｒｉ综合征的ＣＴ表现，ＣＴ显示肝尾叶增大５０例（９６％），肝脏呈低度密度或密度不均，４２例（８１％）肝静脉未明显，２２例（４２％）见有肝内侧枝血管，４９例（９４％）有肝外侧枝血管，作者认为ＣＴ检查对Ｂｕｄｄ－Ｃｈｉａｒｉ综合征有较高的诊断价值。     

坡地系统土壤侵蚀定量评价方法

区域性土壤侵蚀的定量评在涉及到泥沙输移的非连续性难题和众多的非确定性因素，目前应用较普遍的小区定量难以适用。所提出的定量评价方法是利用ＧＩＳ技术、模糊数学、将以分布参数为特征的区域坡地系统划分成若干类具有集中参数特征的基本侵蚀单元，结合ＵＳＬＥ方程来模拟空间上不同侵蚀背景条件下土壤侵蚀的强度，并可以确定影响土壤侵蚀的主要因子及其排序，该方法适用性强，可用于不同空间尺度的土壤侵蚀定量评价。     

Separate Analysis of Remote Sensing Information of Structures of Different Geological Periods and Quantitative Study of Corresponding Tectonic Stress Fields

The structural feature shown on a remote sensing image is a synthetic result ofcombination of the deformations produced during the entire geological history of an area.Therefore, the respective tectonic stress field of each of the different stages in the complexdeformation of an area can be reconstructed in three steps: (1) geological structures formed atdifferent times are distinguished in remote sensing image interpretation; (2) structuraldeformation fields at different stages are determined by analyzing relationships betweenmicrostructures (joints and fractures) and the related structures (folds and faults); and (3)tectonic stress fields at different stages are respectively recovered through a study of the featuresof structural deformation fields in different periods. Circular structures and related circlular and radial joints are correlated in space to con-cealed structural rises. The authors propose a new method for establishing a natural model ofthe concealed structural rises and calculating the tectonic stress field by using quantitative dataof the remote sensing information of circular structures and related linear structures.     

四川盆地碳酸盐岩油气勘探实践与认识

四川盆地烃源十分丰富。但油气演化程度高,大多已进入高成熟和过成熟阶段,至今只在侏罗系发现有油藏,三叠系及其更老地层皆为气藏。储层主要为碳酸盐岩,其特点是低孔低渗,平均孔隙度仅1.7%,平均渗透率小于1×10~(-3)μm~2,但其中的“孔洞发育层段”平均孔隙度可达3%～6%。根据四十年的勘探经验,加强预探并争取新发现是四川盆地油气勘探发展的关键。预探中,按构造带规划大中型气田勘探目标,将成藏条件相似、地域上相邻的局部圈闭群作为一个整体勘探对象,实行稀井广探,少井高效。“八五”以来,在高陡构造带勘探技术、储层横向预探技术等方面有长足的进步,勘探成效不断提高,实现了资源序列的良性循环。     

青藏高原Pn波研究进展及问题

简要总结了青藏高原地区Pn波速度结构、各向异性研究进展；介绍了Pn波速度结构、各向异性等在岩石圈结构、构造背景反映等方面的应用研究进展。分析了目前青藏高原Pn波研究中存在的一些问题。     

GRADIENT DISTRIBUTION OF ACID RAIN IN THE SCENIC RESORT OF THE BAIYUN MOUNTAIN IN GUANGZHOU

1 INTRODUCTION Sitting in the central part of the Pearl River Delta, Guangzhou is one of the cities in China that are most polluted by acid rain. Broad attention has been brought to the problem. Since the early 1980s, a series of observation and studies h…     

CHARACTERISTICS OF ATMOSPHERIC HEAT SOURCE ASSOCIATED WITH THE SUMMER MONSOON ONSET OVER THE SOUTH CHINA SEA AND THE POSSIBLE MECHANISM RESPONSIBLE FOR ITS LATE OR EARLY ONSET

The characteristics of atmospheric heat source associated with the summer monsoon onset in the South China Sea (SCS) are studied using ECMWF reanalysis data from 1979 to 1993. A criterion of the SCS summer monsoon onset is defined by the atmospheric hea…     

关于地基承载力的探讨

以土质地基为研究对象 ,结合载荷试验 p s曲线 ,应用土体的极限平衡理论 ,对地基土的变形性状、地基土承载力以及承载力修正等问题进行了分析。分析结果显示 :地基土承载力不单是地基土抗剪强度指标的函数 ,同时还与作用其上的基础埋深及基础宽度等因素密切相关。进行地基基础设计时 ,应根据实际的基础埋深与宽度对勘察资料中的地基土承载力进行修正 ,并提出了有关承载力修正的建议     

Evidence for high-Ca boninite magmatism from Paleogene primitive low-K tholeiite, Mukoojima, Hahajima Island group, southern Bonin (Ogasawara) forearc, Japan

Abstract   High-Ca boninitic inclusions are found in primitive low-K tholeiite from Mukoojima (Mukoo-Jima), an islet in the Hahajima Island group, Bonin (Ogasawara) forearc, Japan. While Chichijima Island group, 50 km north of Hahajima Island group, is well known as a type locality of boninite, there has been no report of boninitic rocks from the Hahajima Island group. The high-Ca boninitic inclusions are aphanitic and contain olivine, Ca-rich clinopyroxene, plagioclase, chromian spinel, opaque minerals and dark brown glass. The mode of occurrence of the inclusions and host tholeiite under the microscope indicates mingling of these two magmas, suggesting intimate association in space and time of the boninite and primitive tholeiite magmas around the Hahajima Island group in Paleogene time. Primitive compositions and slightly different Sr and Nd isotopic ratios suggest that these two magmas are derived from two distinct mantle sources. These two mantle sources were present at the same time around the Hahajima Island group, southern Bonin forearc. The source of the high-Ca boninite was higher in water content and/or shallower in depth compared to that of the primitive tholeiite.     

山东省气候变化及其对冬小麦生产潜力的影响

利用全省 2 7个台站 1 96 1～ 1 998年的温度、降水、日照等基本气象要素资料 ,对山东省气候变化特点进行了分析 ,并对冬小麦生产潜力进行了计算、分析。结果表明 ,山东省年、季平均气温呈波动性增暖趋势 ,降水量呈减少趋势。气候变暖有利于生产潜力的提高 ,冬小麦气候生产潜力总的变化趋势是波动性的上升 ,但较光温生产潜力倾向率小 ,反映了小麦生育期内光、温、水的综合影响。