新疆博格达山北缘晚古生代一中生代古水流样式转折及其构造意义     

李玮胡健民  黎敦朋刘金侠孙宜朴  梁积伟 《沉积学报》2007,25(2):283-292

新疆准噶尔盆地南缘博格达山北缘地区古水流方向在晚古生代到中生代期间发生过三次重要的转变.晚石炭世晚期以前指向南,晚石炭世晚期到二叠纪期间指向东、南东东向,三叠纪-侏罗纪指向南,白垩纪及其以后指向北.结合盆地物源和沉积环境分析,博格达山北缘自晚古生代以来可划分为四个构造演化阶段,古流向转折期为盆地各期构造演化的分界线,它们是盆地对周缘造山带构造演化沉积响应的重要记录.另一方面,古水流转折时间资料的获得,对准噶尔盆地周缘不同构造带的隆升时代是一个非常重要的限定.晚石炭世晚期至二叠纪,古水流资料指示沉积物主要来自准噶尔盆地西部,准噶尔盆地西-西北缘强烈隆升,自三叠纪早期开始到侏罗纪晚期,准噶尔盆地北缘抬升,博格达山北缘沉积物主要来自北方;侏罗纪晚期到白垩纪,古水流指示沉积物主要来自盆地南部,博格达山隆起并遭受剥蚀.然而,什么原因造成石炭纪末以来,准噶尔盆地周缘几个造山带顺时针方向依次隆起,有待进一步研究.  相似文献   

Spatial patterns of terrestrial net ecosystem productivity in China during 1981–2000   总被引：1，自引：0，他引：1  

Tao Bo  Cao MingKui  Li KeRang  Gu FengXue  Ji JinJun  Huang Mei  Zhang LeiMing 《中国科学D辑(英文版)》2007,50(5):745-753

As the third largest country in the world, China has highly variable environmental condition and ecological pattern in both space and time. Quantification of the spatial-temporal pattern and dynamic of terrestrial ecosystem carbon cycle in China is of great significance to regional and global carbon budget. In this study, we used a high-resolution climate database and an improved ecosystem process-based model to quantify spatio-temporal pattern and dynamic of net ecosystem productivity (NEP) in China and its responses to climate change during 1981 to 2000. The results showed that NEP increased from north to south and from northeast to southwest. Positive NEP (carbon sinks) occurred in the west of Southwest China, southeastern Tibet, Sanjiang Plain, Da Hinggan Mountains and the mid-west of North China. Negative NEP (carbon sources) were mainly found in Central China, the south of Southwest China, the north of Xinjiang, west and north of Inner Mongolia, and parts of North China. From the 1980s to 1990s, the increasing trend of NEP occurred in the middle of Northeast China Plain and the Loess Plateau and decreasing trends mainly occurred in a greater part of Central China. In the study period, natural forests had minimal carbon uptake, while grassland and shrublands accounted for nearly three fourths of the total carbon terrestrial uptakes in China during 1981–2000. Supported by the Ministry of Science and Technology of China (G2002CB412507), the Major Program of the National Natural Science Foundation of China (Grant No.30590384), the “Hundred Talent” Program of the Chinese Academy of Sciences, and K C WONE Education Foundation  相似文献   

Analysis on the coupling law between economic development and the environment in (U)rümqi city     

WANG HongWei  ZHANG XiaoLei  WEI ShanFeng  KANG Hong 《中国科学D辑(英文版)》2007,50(Z1)

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日本数值预报产品在邯郸大雪预报中的释用          下载免费PDF全文

田秀霞刘云柱  刘思华 《气象与环境科学》2007,30(B09):35-36

根据1995—2005年冬季邯郸市气象台现有的28个月日本数值预报产品资料，对≥5mm的降水预报日数和全市16个观测站降水实况，按预报评分量级进行分县检验和天气系统分型检验，总结出产生大雪以上降水的天气类型，并确立大雪和暴雪预报指标。  相似文献   

Improved ENSO simulation in regional coupled GCM using regressive correction method   总被引：1，自引：0，他引：1  

Fu WeiWei  Zhou GuangQing 《中国科学D辑(英文版)》2007,50(8):1258-1265

A regressive correction method is presented with the primary goal of improving ENSO simulation in regional coupled GCM. It focuses on the correction of ocean-atmosphere exchanged fluxes. On the basis of numerical experiments and analysis, the method can be described as follows: first, driving the ocean model with heat and momentum flux computed from a long-term observation data set; the pro-duced SST is then applied to force the AGCM as its boundary condition; after that the AGCM’s simula-tion and the corresponding observation can be correlated by a linear regressive formula. Thus the re-gressive correction coefficients for the simulation with spatial and temporal variation could be obtained by linear fitting. Finally the coefficients are applied to redressing the variables used for the calculation of the exchanged air-sea flux in the coupled model when it starts integration. This method together with the anomaly coupling method is tested in a regional coupled model, which is composed of a global grid-point atmospheric general circulation model and a high-resolution tropical Pacific Ocean model. The comparison of the results shows that it is superior to the anomaly coupling both in reducing the coupled model ‘climate drift’ and in improving the ENSO simulation in the tropical Pacific Ocean.  相似文献   

Exposure of global mountain systems to climate warming during the 21st Century   总被引：3，自引：0，他引：3  

D. Nogus-Bravo  M.B. Araújo  M.P. Errea  J.P. Martínez-Rica 《Global Environmental Change》2007,17(3-4):420-428

We provide an assessment of surface temperature changes in mountainous areas of the world using a set of climate projections at a 0.5° resolution for two 30-year periods (2040–2069 and 2070–2099), using four Intergovernmental Panel for Climate Change (IPCC) emission scenarios and five AOGCM. Projected average temperature changes varied between +3.2 °C (+0.4 °C/per decade) and +2.1 °C (+0.26 °C/per decade) for 2055 and +5.3 °C (+0.48 °C/per decade) and +2.8 °C for 2085 (+0.25 °C/per decade). The temperature is expected to rise by a greater amount in higher northern latitude mountains than in mountains located in temperate and tropical zones. The rate of warming in mountain systems is projected to be two to three times higher than that recorded during the 20th century. The tendency for a greater projected warming in northern latitude mountain systems is consistent across scenarios and is in agreement with observed trends. In light of these projections, warming is considered likely to affect biodiversity (e.g., species extinctions, changes in the composition of assemblages), water resources (e.g., a reduction in the extent of glaciated areas and snow pack), and natural hazards (e.g., floods). Accurate estimate of the effects of climate change in mountain systems is difficult because of uncertainties associated with the climate scenarios and the existence of non-linear feedbacks between impacts.  相似文献   

滇西重力断层运动时间分布特征的初步研究   总被引：12，自引：11，他引：1  

申重阳  李辉  王琪  游新兆  甘家思  卓力格图 《大地测量与地球动力学》2002,22(2):68-74

地表观测的重复重力数据综合反映了地表观测点的位置变化、地壳内部密度变化和地壳内部构造变形，通过反演这些数据得到的断层位错运动的时间变化综合反映了地壳内部形变和密度变化的耦合运动。为此，利用滇西1985年以来的重复重力观测数据，结合地质调查和地球物理推断结果确定断层运动模型作为约束，并考虑到观测数据和模型粗差，反演获得了滇西主要活动断裂运动的时间变化分布。结果表明，滇西1985－2001年断层运动的时间变化表现出断层往复运动特征，较好地反映了区内Ms≥6.0地震（如1996年丽江Ms7.0地震、1998年宁蒗Ms6.2地震和2000年姚安Ms6.5地震等）的孕育过程。指出强震孕育过程遵循地壳内部密度和地壳形变耦合运动模式（简称DD耦合运动模式），并给出了断层位错DD耦合运动模式的基本图像。  相似文献   

On Chinese earthquake history — An attempt to model an incomplete data set by point process analysis   总被引：1，自引：0，他引：1  

W. H. K. Lee  D. R. Brillinger 《Pure and Applied Geophysics》1979,117(6):1229-1257

Since the 1950s, the Academia Sinica in Peking, People's Republic of China, has carried out extensive research on the Chinese earthquake history. With a historical record dating back some 3000 years, a wealth of information on Chinese earthquakes exists. Despite this monumental undertaking by the Academia Sinica, much work is still necessary to correct the existing earthquake data for historical changes in population, customs, modes of communication, and dynasties. In this paper we report on the status of our investigation of Chinese earthquake history and present some preliminary results. By applying point process analysis of earthquakes in Central China, we found suggestions of (1) lower earthquake activity at intervals of about 175 years and 375 years, and (2) higher earthquake activity at an interval of about 300 years.  相似文献   

水文学与水力学相结合的南四湖洪水预报模型          下载免费PDF全文

李致家  包红军  孔祥光  陈界仁  杨殿亮 《湖泊科学》2005,17(4):299-304

南四湖流域是一个复杂的大流域，是东线南水北调的重要调节湖泊之一，也是干旱和洪水频繁流域．本文首先采 用分布式的新安江模型，对有实测流量资料的支流流域进行了模型参数率定，洪量预报达到了一定的精度，建立了南四湖 流域的洪水预报模型．采用一维、二维水力学模型并与水文学模型耦合进行上级湖的流量演进以及二级坝水利枢纽的 调度．  相似文献   

用偏硼酸锂熔样ICP-AES法测定岩石中Si、Zr等12个元素   总被引：5，自引：0，他引：5  

鲁慧文  王英杰 《吉林地质》2005,24(2):118-122

本方法采用偏硼酸锂分解样品，电感耦合等离子体发射光谱法测量，在同一份溶液中可以测定硅、钠、铝、钙、镁、铁、钛、锰、钡、锶、钒、锆等元素。通过对国家标准物质测定，其准确度、精密度能满足岩石样品中定量分析要求。  相似文献