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31.
An empirical kinematic method developed by Hakamada and Akasofu (1982) is calibrated on the basis of a one-dimensional MHD solution. The calibrated results are used to simulate the stream-stream interaction and the background corotating structure in a simple situation and also during 22 November–6 December 1977. The solar wind disturbances caused by solar activities during this period are then introduced into the above background stream in simulating the heliospheric disturbance event which was observed by an aligned set of spacecraft at distances between 0.6 and 1.6 a.u. The observations and the simulated results are satisfactory, and a little more refinement in the simulation could reconstruct reasonably well the data by filling the data gaps in the solar wind speed, the density and the IMF magnitude.  相似文献   
32.
The Tamtsag Basin is located in the extreme eastern portion of the Mongolia. The Basin and its counterpart in China (the Hailar Basin) are united a whole basin on the structural setting. In recent years, the Tamtsag Basin attracts more and more attention with the important exploration discovered in the 19th block by SOCO and in Hailar Basin of China. This paper discusses the exploration potential of Tamtsag Basin from the viewpoint of petroleum geology.  相似文献   
33.
针对信息系统安全的考虑,介绍在PowerBuilder环境中对用户权限的具体控制.  相似文献   
34.
层序-岩相古地理图及其编制   总被引:24,自引:3,他引:21  
在中国岩相古地理研究历史简要回顾基础上,以层序地层学理论为指导,就如何编制层序-岩相古地理图进行了讨论,首先是编图单元的选择,一是以层序内的体系域为成图单元,二是以相关界面为成图单元.具体方法是在对所研究的层位进行精细的层序地层分析的基础上,进行层序对比,建立等时地层格架.在上述基础上系统编制不同层序内的各体系域或有关界面沉积时的古地理图.以此方法所编制的层序-岩相古地理图具有重要的理论和现实意义,主要表现为更具有等时性、成因连续性和实用性,能更好地反映一个地区在统一地质作用场中的各种地质信息和综合效应;可以揭示出一些新的地质现象,对于覆盖区相带展布及变化具更合理的预测性.进而以中国南方二叠纪为例,在层序划分、对比的基础上,系统编制了一个完整的海平面变化旋回条件下的层序-岩相古地理图,并描述了其平面展布特点.  相似文献   
35.
阿吾拉勒山体西段发育了厚度巨大的下二叠统火山岩,这些火山岩均属碱性玄武岩系列,以钾质类型为主,钠质类型次之,岩浆演化呈现出跨越B型趋势。这种火山活动是在大陆地壳内部产生的,代表了陆内裂谷演化的早期阶段。在早二叠世末期,由于受到新源运动的影响,这种火山活动被终止了。  相似文献   
36.
首先指出目前星风吸积模型中理论上的不自洽,考虑到δr≠0,重新推导轨道参量变化方程,消去了理论上的不自洽.提出一个新模型:首次将星风吸积同内禀AGB星核合成模型结合起来计算钡(Ba)星的重元素超丰,并将计算结果与观测值进行了比较.各参量按标准情况取值时,计算结果不太理想.取Bondihoyle吸积率的0.5倍或取较大的星风速率时,对于较长轨道周期(P>1000天)的Ba星,计算结果与观测值基本符合;而较短轨道周期(P<600天)的Ba星,其重元素超丰机制可能是盘吸积  相似文献   
37.
38.
After the survey of pollution sources, a study on surface water quality assessment and forecast is given by means of grey system method, fuzzy mathematical method and multiple-index method. Based on it, aquatic environment quality features, treatment measures and environmental strategies of the area are proposed. The quality of aquatic environment of 5 rivers in the Tumen River area is studied. The results show that the pollution of surface water is serious; water quality of most rivers is between grade IV and V except the Hunchun River, being higher than grade IV standard; pollution levels of most rivers have been basically controlled except the of Burhatong River, which is deteriorating gradually. Pollutants of the rivers are comparatively regular, mainly are SS, COD, BOD, AR-OH, NH3-N. The main pollution trades are chemical fibre industry, pulp and paper making industry and mining industry. If the growth rate of gross industrial product is higher than 25 percent under the encouraging-model of regional exploitation, the pollutants’ load will overtake the bearing capacity of aquatic environment. Thus some protection program against pollution must be worked out in order to achieve the harmonious development of economy society and environment. A project from “Studies on Earlier Stage of Regional Development” of the Chinese Academy of Sciences  相似文献   
39.
介绍了云南天文台天体测量工作的发展过程,论述了在空间时代地面光学基本天体测量的必要性和应具备的条件,并且叙述了在新的要求和条件下,地面光学基本天体测量工作应该发挥的作用和广阔的发展前景。  相似文献   
40.
Based on the δ13C and δ18O fluctuation of lacustrine carbonate, CaCO3 content and sporo-pollen data, a palaeoclimatic history of Bosten Lake during the Holocene has been outlined, several stages of climatic changes are divided, and the following result es are obtained: (1) Palaeoclimatic changes revealed by carbonate isotope around Bosten Lake are basically identical with that revealed by other geological records in Xinjiang. Environmental changes presented apparent Westlies Style model: during cold period, relative humidity increased, δ18O, δ13C and CaCO3 appeared low; but in warm periods, the dry regime aggravated. (2) The temperature reflected by δ18O exist evident features being increase in the late period during the Holocene. Together with the δ13C, pollen and CaCO3 analyses, several cold and warm phases which are of broad regional significance can be identified. The warm peaks occurred at about 11.0 ka B.P., 9.4 ka B.P., 7.5 ka B.P., 5.0 ka B.P., 3.0 ka B.P. and 2.0 ka B.P.; the cold peaks at 11.5 ka B.P., 10.5 ka B.P., 8.8 ka B.P., 5.5 ka B.P., 3.3 ka B.P., 2.2 ka B.P. and 1.5 ka B.P.. (3) Several climatic events with the nature of “abrupt climatic changes” are revealed in the periods of 11.0 ka B.P. −10.5 ka B.P., 9.4 ka B.P. −8.8 ka B.P., 5.5 ka B.P. −5.0 ka B.P. and 2.0 ka B.P. −1.5 ka B.P.. (4) The results show that carbonate isotopic record of lacustrine sediment in arid area is very sensitive to climatic changes, and may be play a very important role in understanding the features and mechanism of palaeoclimatic changes.  相似文献   
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