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92.
镇江大力山中,下三叠统沉积特征及环境分析 总被引:2,自引:0,他引:2
镇江大力山中、下三叠统青龙组2段和3段发育的瘤体灰岩属盆地边缘斜坡环境,杂乱瘤体灰岩横向相变为盆地边缘斜坡滑塌重力流成因(深水)的泥晶砾屑灰岩;蠕粒灰岩则为台地前缘斜坡的浅水沉积环境,与浅水重力流的砾屑泥晶灰岩共生. 相似文献
93.
新疆西天山哈勒尕提-木祖克铁铜铅锌矿床地质特征及成矿条件分析 总被引:1,自引:0,他引:1
哈勒尕提-木祖克铁铜铅锌矿床是近年来在新疆西天山博罗科努成矿带内发现的一处典型的矽卡岩型铜多金属矿床,目前为中型规模,有达到大型矿床的潜力。矿体赋存于大瓦布拉克岩体与上奥陶统呼独克达坂组(O3h)大理岩、大理岩化灰岩的接触带。成矿受岩浆岩、地层岩性和接触带构造"三位一体"联合控制。大瓦布拉克岩体主要岩性为二长花岗岩和花岗闪长岩,岩石地球化学显示高硅、准铝、低镁、富碱、富钾,为I型花岗岩,富集大离子亲石元素,相对亏损高场强元素,具俯冲带岩浆岩的地球化学特点。呼独克达坂组(O3h)碳酸盐岩地球化学性质活泼且富含铜、锌,有利于含矿热液交代成矿,是区域找矿的优势层位。接触带构造既是成矿地球化学障,又是良好的成矿热液运移通道,直接控制着矿体的产出。 相似文献
94.
The Wenchuan Earthquake that occurred in May of 2008 caused damages to large areas of Sichuan, Gansu, and Shaanxi provinces
in China. Reports from local governments and related management agencies show that the giant panda nature reserves in the
earthquake-hit areas were heavily damaged. Our estimates in this paper of the impacts of the earthquake on the giant panda
in the earthquake-hit areas were made based on the interpretation of remote sensing images and information collected by field
survey. A rapid assessment method was designed to estimate the damages of the earthquake on giant panda habitats. By using
visual interpretation methods, we decoded the remote sensing images of the disaster area in the 49 giant panda nature reserves.
Research results showed that the Wenchuan Earthquake and the succeeding secondary geological disasters caused great damages
to the giant panda nature reserves and disturbed the normal life of the giant pandas there (e.g., landscape fragmentation
increased significantly). Undoubtedly, the life of the giant pandas there was affected. However, although the earthquake caused
certain impacts on the giant pandas, it did not really threat their survival. Even so, we still strongly advocate for protection
of the giant pandas, and have prioritized a couple of measures to be taken to restore the giant panda nature reserves in the
earthquake-hit areas. 相似文献
95.
Ge Verver Frank Raes Daan Vogelezang Doug Johnson 《Tellus. Series B, Chemical and physical meteorology》2000,52(2):126-140
A review is given of the climatological and actual meteorological conditions in the sub‐tropical northeast Atlantic, during June–July 1997, when the 2nd Aerosol Characterization Experiment (ACE‐2) took place. Surface pressure maps, trajectory calculations and in‐situ measurements show how the outflow of European pollution into the marine boundary layer of this area is determined by the location of the Azores high pressure cell. Observations during ACE‐2 and 3 preceding summers show that pollution outbreaks both from the Iberian peninsula and from northern or central Europe can occur during such situations. During ACE‐2, an unusually low number of strong North African dust outbreaks were recorded at the free tropospheric station of Izaña (Tenerife, 2360 m asl), although dust was recorded aloft the station. 相似文献
96.
Stephen R. Kane Donald P. Schneider Jian Ge 《Monthly notices of the Royal Astronomical Society》2007,377(4):1610-1622
Radial velocity surveys for extrasolar planets generally require substantial amounts of large telescope time in order to monitor a sufficient number of stars. Two of the aspects which can limit such surveys are the single-object capabilities of the spectrograph, and an inefficient observing strategy for a given observing window. In addition, the detection rate of extrasolar planets using the radial velocity method has thus far been relatively linear with time. With the development of various multi-object Doppler survey instruments, there is growing potential to dramatically increase the detection rate using the Doppler method. Several of these instruments have already begun usage in large-scale surveys for extrasolar planets, such as Fibre Large Array Multi Element Spectrograph (FLAMES) on the Very Large Telescope (VLT) and Keck Exoplanet Tracker (ET) on the Sloan 2.5-m wide-field telescope.
In order to plan an effective observing strategy for such a program, one must examine the expected results based on a given observing window and target selection. We present simulations of the expected results from a generic multi-object survey based on calculated noise models and sensitivity for the instrument and the known distribution of exoplanetary system parameters. We have developed code for automatically sifting and fitting the planet candidates produced by the survey to allow for fast follow-up observations to be conducted. The techniques presented here may be applied to a wide range of multi-object planet surveys. 相似文献
In order to plan an effective observing strategy for such a program, one must examine the expected results based on a given observing window and target selection. We present simulations of the expected results from a generic multi-object survey based on calculated noise models and sensitivity for the instrument and the known distribution of exoplanetary system parameters. We have developed code for automatically sifting and fitting the planet candidates produced by the survey to allow for fast follow-up observations to be conducted. The techniques presented here may be applied to a wide range of multi-object planet surveys. 相似文献
97.
This study explores the characteristics of high temperature anomalies over eastern China and associated influencing factors using observations and model outputs. Results show that more long-duration (over 8 days) high temperature events occur over the middle and lower reaches of the Yangtze River Valley (YRV) than over the surrounding regions, and control most of the interannual variation of summer mean temperature in situ. The synergistic effect of summer precipitation over the South China Sea (SCS) region (18°-27°N, 115°-124°E) and the northwestern India and Arabian Sea (IAS) region (18°-27°N, 60°-80°E) contributes more significantly to the variation of summer YRV temperature, relative to the respective SCS or IAS precipitation anomaly. More precipitation (enhanced condensational heating) over the SCS region strengthens the western Pacific subtropical high (WPSH) and simultaneously weakens the westerly trough over the east coast of Asia, and accordingly results in associated high temperature anomalies over the YRV region through stimulating an East Asia-Pacific (EAP) pattern. More precipitation over the IAS region further adjusts the variations of the WPSH and westerly trough, and eventually reinforces high temperature anomalies over the YRV region. Furthermore, the condensational heating related to more IAS precipitation can adjust upper-tropospheric easterly anomalies over the YRV region by exciting a circumglobal teleconnection, inducing cold horizontal temperature advection and related anomalous descent, which is also conducive to the YRV high temperature anomalies. The reproduction of the above association in the model results indicates that the above results can be explained both statistically and dynamically. 相似文献
98.
A Dipole Pattern of Summer Precipitation over Mid-high Latitude Asia and Related Snow Cover Anomalies in the Preceding Spring 下载免费PDF全文
A dipole pattern of summer precipitation over the mid-high latitudes of Asia, which is characterized by opposing summer precipitation variations between the Mongolian and Northeast China (MNC) region and the West Siberian Plain (WSP), is found to be clear and stable on both interdecadal and interannual scales during 1981- 2011. Spring snow cover anomalies over a small region within the WSP and the Heilongjiang River (HR) region are closely related to the variation of this dipole mode during the subsequent summer, and they can therefore be considered as forecasting factors. Our statistical results imply a potential process explaining the relationship between the spring snow anomalies and the summer rainfall dipole. Corresponding to the snow anomalies, Rossby waves propagate along a path from the WSP region, via the Mongolian Plateau, to the Stanovoy Range during summer. At the same time, Rossby-wave energy divergences and convergences along this path maintain and reinforce an anomalous cyclone and anticyclone pairing over the Asian continent, which is significantly linked to opposite summer precipitation anomalies between the MNC and WSP regions. Numerical experiments are need- ed to further confirm the above conjecture and demonstrate the detailed physical mechanisms linking the spring snow cover anomalies and summer precipitation dipole. 相似文献
99.
Jixing Ge 《天文和天体物理学研究(英文版)》2022,(1):30-45
In this paper,we present a new gas-grain chemical code for interstellar clouds written in pure Python(GGCHEMPY(GGCHEMPY is available on https://github.com/Jixin... 相似文献
100.
整数模糊度参数的快速检索算法 总被引:1,自引:0,他引:1
GPS快速定位中,由于模糊度参数之间的强相关性,模糊度参数置信区间定义的检索区域比相应的置信椭球大得多。本文通过模糊度参数向量的正交变换,定义出包含模糊度参数置信椭球的最小正交多面体,借助在其中构造的均匀正交网格点,找出置信椭球中的所有整数模糊度参数向量。该方法显著地减少了整数模糊度参数的检索范围,提高了计算效率。 相似文献