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161.
马脑壳金矿床构造变形复杂且研究薄弱,作者通过野外地质填图并结合矿山生产勘探,以构造解析为研究方法,对马脑壳金矿床的变形特征与金成矿关系进行了研究。构造解析表明区内地层在成岩期遭受了同生变形,成岩后先后遭受了NE-SW向的挤压褶皱逆冲变形([T33])、左行走滑变形并伴随伸展塌陷变形(J1-2),宏观上表现为推覆—走滑控矿,即印支末期推覆作用形成的变形样式整体控制着金矿体的产出和分布,后期走滑作用叠加改造导致的张性破裂样式控制着金矿化强度,成矿作用主要发生在左行走滑变形阶段(J1-2),成矿机制是燕山早中期(J1-2)西秦岭地区由强烈的挤压动力体制向弥散间隔密集的走滑动力体制转换,导致含矿热液沿构造薄弱带(如区内F2断裂)上升迁移并在构造动力体制转换强烈的区域发生大规模金沉淀。西秦岭地区和松潘—甘孜地区的微细浸染型金矿极有可能形成于燕山早期(J1-2)由挤压向走滑构造动力体制转过程中。 相似文献
162.
文章以新疆石河子气象局1961—2008年年均气温、年降水量和年均日照观测资料为研究对象,运用趋势拟合方法、Morlet小波和Yamamoto方法分析其趋势变化、周期及突变特性。结果表明:48年中,石河子年平均气温和年降水量呈递增趋势,年均日照呈微弱递减趋势,均有一定的周期性,在不同的年份发生了突变,最后分析了气候变化对农业生产的影响。 相似文献
163.
Recent glacial retreat in High Asia in China and its impact on water resource in Northwest China 总被引:48,自引:0,他引:48
YAO Tandong WANG Youqing LIU Shiying PU Jianchen SHEN Yongping & LU Anxin .Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing China .Cold Arid Regions Environmental Engineering Research Institute Chinese Academy of Sciences Lanzhou China 《中国科学D辑(英文版)》2004,47(12):1065-1075
There are about 46298 glaciers in the High Asiain China, the total glacial area is about 59406 km , andtotal glacial volume about 5590 km3. These glaciersmainly concentrate around the Himalayas Mountains,Nyainqentanglha Mountains, Kunlun Mountains,Karakoram Mountains and Tianshan Mountains. Theglaciers in the Tibetan Plateau are the major compo-nent of the glaciers in the High Asia in China. Theseglaciers extend north to the arid and desert regions,and become the main water resource in … 相似文献
164.
David G. Barber Matthew G. Asplin Tim N. Papakyriakou Lisa Miller Brent G. T. Else John Iacozza C. J. Mundy M. Gosslin Natalie C. Asselin Steve Ferguson Jennifer V. Lukovich Gary A. Stern Ashley Gaden Monika Pu?ko N.-X. Geilfus Fei Wang 《Climatic change》2012,115(1):135-159
Change and variability in the timing and magnitude of sea ice geophysical and thermodynamic state have consequences on many aspects of the arctic marine system. The changes in both the geophysical and thermodynamic state, and in particular the timing of the development of these states, have consequences throughout the marine system. In this paper we review the ??consequences?? of change in sea ice state on primary productivity, marine mammal habitats, and sea ice as a medium for storage and transport of contaminants and carbon exchange across the ocean-sea-ice-atmosphere interface based upon results from the International Polar Year. Pertinent results include: 1) conditions along ice edges can bring deep nutrient-rich ??pacific?? waters into nutrient-poor surface waters along the arctic coast, affecting local food webs; 2) both sea ice thermodynamic and dynamic processes ultimately affect ringed seal/polar bear habitats by controlling the timing, location and amount of surface deformation required for ringed seal and polar bear preferred habitat 3) the ice edges bordering open waters of flaw leads are areas of high biological production and are observed to be important beluga habitat. 4) exchange of climate-active gases, including CO2, is extremely active in sea ice environments, and the overall question of whether the Arctic Ocean is (or will be) a source or sink for CO2 will be dependent on the balance of competing climate-change feedbacks. 相似文献
165.
裂隙岩体内的洞室围岩块体稳定问题是抽水蓄能电站地下厂房建设中要解决的重要工程地质问题。为了在厂房开挖之前较准确地预测不稳定块体的发育位置,本文以某抽水蓄能电站为例,对厂房探洞内的裂隙进行统计分析,结合厂房区构造断层的发育情况,确定了裂隙发育规律;根据裂隙发育规律将厂房区岩体划分为A、B、C、D、E 5个构造分区;并利用Unwedge程序,以各分区裂隙组合为基础,确定可能形成的块体位置,评价了其稳定性状况。研究结果表明,裂隙受多期构造控制,在一定范围内具有方向性,A、E区优势裂隙与构造产状接近,B、C、D区优势裂隙与构造产状斜交;裂隙在厂房上、下游侧边墙各形成6处潜在不稳定块体,顶拱处形成10处潜在不稳定块体,右端墙处形成1处潜在不稳定块体。 相似文献
166.
Numerous elongated mounds and channels were found at the top of the middle Miocene strata using 2D/3D seismic data in the Liwan Sag of Zhujiang River Mouth Basin(ZRMB) and the Beijiao Sag of Qiongdongnan Basin(QDNB). They occur at intervals and are rarely revealed by drilling wells in the deepwater areas. Origins of the mounds and channels are controversial and poorly understood. Based on an integrated analysis of the seismic attribute, palaeotectonics and palaeogeography, and drilling well enco... 相似文献
167.
This paper is dedicated to study the dynamic response of a thin‐plate resting on a layered poroelastic half‐space under a moving traffic load. Based on the dynamic poroelastic theory of Biot, the general solutions of the homogeneous poroelastic foundation are obtained by Fourier translation. By using the transmission and reflection matrices method in the frequency domain, the equivalent stiffness of the layered poroelastic half‐space is presented. Kirchhoff's hypotheses are applied to obtain the vertical displacement of the thin plate. By using the inverse Fourier transform, the time domain solution is obtained. As an example of three layers, the influences of the load velocity, the material properties of poroelastic layers, and the flexural rigidity of the plate on the response of the pavement system are examined. Analyses show that a soft intermediate layer results in the significant increase of vertical displacement of road pavement. Comparison with the existing work validates the present model. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
168.
以新月时月亮的射电辐射为温度基准和准口面温度定标的方法,在22GHz频率上于1993年7月~3月测量了13.7m射电望远镜抛物面天线的增益。根据测量的增益值(67.10─±0.07db)定标了太阳射电流量,流量测量的系统差为±5.8%,偶然差为±2.7%,测量的宁静太阳亮温度(非源区)为10100±300K。除此之外,还推导和计算了不同源模型下的天线方向图改正因子Ks,并计算了太阳射电源的流量密度。 相似文献
169.
170.
Yaohui Li Cailing Zhao Tiejun Zhang Wei Wang Haixia Duan Yuanpu Liu Yulong Ren Zhaoxia Pu 《Acta Meteorologica Sinica》2018,32(6):896-908
This study examines the impacts of land-use data on the simulation of surface air temperature in Northwest China by the Weather Research and Forecasting (WRF) model. International Geosphere–Biosphere Program (IGBP) landuse data with 500-m spatial resolution are generated from Moderate Resolution Imaging Spectroradiometer (MODIS) satellite products. These data are used to replace the default U.S. Geological Survey (USGS) land-use data in the WRF model. Based on the data recorded by national basic meteorological observing stations in Northwest China, results are compared and evaluated. It is found that replacing the default USGS land-use data in the WRF model with the IGBP data improves the ability of the model to simulate surface air temperature in Northwest China in July and December 2015. Errors in the simulated daytime surface air temperature are reduced, while the results vary between seasons. There is some variation in the degree and range of impacts of land-use data on surface air temperature among seasons. Using the IGBP data, the simulated daytime surface air temperature in July 2015 improves at a relatively small number of stations, but to a relatively large degree; whereas the simulation of daytime surface air temperature in December 2015 improves at almost all stations, but only to a relatively small degree (within 1°C). Mitigation of daytime surface air temperature overestimation in July 2015 is influenced mainly by the change in ground heat flux. The modification of underestimated temperature comes mainly from the improvement of simulated net radiation in December 2015. 相似文献