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991.
湖南省沉积型锰矿地质环境及成矿作用   总被引:2,自引:0,他引:2  
石少华 《地质与勘探》2016,52(2):209-219
湖南省沉积型锰成矿时代跨度大,最早由早元古代板溪群马底驿期至早二叠世孤峰期。其中,早南华纪大塘坡期、中奥陶世烟溪期及中二叠世孤峰期为三个最主要成锰集中期,并且大体呈现出朝东南方向成矿时代变新的趋势。成锰沉积盆地是锰矿床就位的重要场所,相应的岩相古地理环境为锰成矿创造了有利条件,即相对缺氧的、滞流的安静环境。这种环境在诸多古地理环境中都可以形成,导致了锰成矿岩相古地理环境的多样性,如浅海陆棚相、次深海棚缘盆地相、次深海台缘斜坡相及陆表次深海海盆相。三个主要成锰期锰成矿作用具有统一性,成矿作用与地壳拉张、海侵事件、缺氧事件等区域性重大地质事件关联密切。  相似文献   
992.
Jurassic Brachiopods and Paleogeography of North Qinghai-Tibetan Plateau   总被引:1,自引:0,他引:1  
This paper deals with Jurassic brachiopods from North Tibet and SouthQinghai and the stratigraphical subdivision there.Based on faunas andstrata,a general outline of the palaeogeographical evolution has been traced outalong the line of plate-tectonic movements.In this paper,10 species of 8 gen-era are described,among which the species Lacunosella rhombica,Pentithyrisvulgaris,Tanyothyris appositus,Apatecosia navicularis and Flabellothyris sp.nov.have been recognized as new.  相似文献   
993.
机载Lidar系统主要由激光发射系统、POS系统、CCD相机、计算机及存储设备等组成,能够快速获取高精度的地面点三维坐标信息以及影像数据,利用Terrasolid软件能够生产DEM、DOM及DLG产品。本文结合文莱高速公路项目详细阐述了机载Lidar系统在高速公路勘测中的应用。  相似文献   
994.
本文利用1987年美国FIFE资料及1986年6月TIPMEX资料,并利用大气长、短波一维辐射传输数值模式,计算了晴空大气状态下地面辐射参数(地面热辐射温度、地表反照率等)对大气长波冷却率、短波加热率廓线的影响。结果表明,地球表面对大气边界层内的热辐射结构影响很大,特别是在高原地区这种影响尤其显著。  相似文献   
995.
基于地表温度-植被指数特征空间的区域土壤水分反演   总被引:5,自引:1,他引:5  
针对目前西北地区广泛存在的农业干旱问题,选取了新疆塔里木盆地北缘渭干河-库车河三角洲绿洲为研究区,选择云量较少的两幅TM影像,建立地表温度-植被指数特征空间。首先利用线性方程拟合了特征空间的上下边界,比较利用归一化植被指数(NDVI)建立的地表温度-植被指数特征空间Ts/NDVI和利用改进型土壤调整植被指数(MSAVI)构建的地表温度-植被指数特征空间Ts/MSAVI形状的差异,并计算得到两种温度植被干旱指数(Temperature vegetation dryness index-TVDI,分别为TVDIN和MTVDI)。对TVDI与同期野外不同深度的实测土壤重量含水量数据进行回归分析,建立TVDI估测土壤水分的经验模型并对模型进行验证。研究结果表明,TVDIN和MTVDI均能够反演表层土壤水分,其中MTVDI与土壤水分相关性比TVDIN与土壤水分相关性要高,MTVDI能够更好地反映区域土壤水分状况,是一种更有效的土壤水分监测方法,对农业干旱监测具有一定的科学依据。  相似文献   
996.
以中国近海典型赤潮藻中肋骨条藻(Skeletonema costatum)为研究对象,考察不同氧饱和度环境下底栖甲壳动物对有机物在沉积物中降解的影响。通过对比不同氧饱和度培养模拟体系中中肋骨条藻在有/无刀额新对虾(Metapenaeus ensis)幼体活动背景下的降解过程,追踪中肋骨条藻中4种主要脂肪酸(C14:0,C16:0,C16:1(7)和C20:5)在100%,50%,25%和0%的氧饱和度体系中的降解行为。结果表明,100%氧饱和度体系中刀额新对虾幼体的活动能明显加快脂肪酸在沉积物中的降解(约为对照组的1.2~1.7倍),特别是对饱和脂肪酸C14:0和C16:0的作用最为明显;而在50%氧饱和度的缺氧体系中,在前三天的培养中,刀额新对虾幼体的活动逐渐减弱直至最终死亡,死亡之前的扰动增加了有机物在次表层沉积物中的埋藏并降低了其降解速率。研究还发现,在100%氧饱和度体系中,刀额新对虾幼体的扰动作用促进大量脂肪酸转移到次表层沉积物和悬浮颗粒中;而在50%氧饱和度体系中,这种转移作用明显变小。对于氧饱和度25%和0%的环境,刀额新对虾幼体在模拟培养开始后迅速死亡,对有机物质降解几乎没有影响。  相似文献   
997.
Using monthly average, maximum, minimum air temperature and monthly precipitation data from 5 weather stations in Mt. Qomolangma region in China from 1971 to 2004, climatic linear trend, moving average, low-pass filter and accumulated variance analysis methods, the spatial and temporal patterns of the climatic change in this region were analyzed. The main findings can be summarized as follows: (1) There is obvious ascending tendency for the interannual change of air temperature in Mt. Qomolangma region and the ascending tendency of Tingri, the highest station, is the most significant. The rate of increasing air temperature is 0.234 oC/decade in Mt. Qomolangma region, 0.302 oC/decade in Tingri. The air temperature increases more strongly in non-growing season. (2) Compared with China and the global average, the warming of Mt. Qomolangma region occurred early. The linear rates of temperature increase in Mt. Qomolangma region exceed those for China and the global average in the same period. This is attributed to the sensitivity of mountainous regions to climate change. (3) The southern and northern parts of Mt. Qomolangma region are quite different in precipitation changes. Stations in the northern part show increasing trends but are not statistically significant. Nyalam in the southern part shows a decreasing trend and the sudden decreasing of precipitation occurred in the early 1990s. (4) Compared with the previous studies, we find that the warming of Mt. Qomolangma high-elevation region is most significant in China in the same period. The highest automatic meteorological comprehensive observation station in the world set up at the base camp of Mt. Qomolangma with a height of 5032 m a.s.l will play an important role in monitoring the global climate change.  相似文献   
998.
定量分析碳排放的影响因素,对降低区域碳排放具有重要的指导意义。利用STIRPAT模型,定量分析江苏省能源消费碳排放量与人口、富裕度(以人均GDP表示)、技术进步(以能源强度表示)和城镇化水平之间的关系,通过岭回归拟合后发现,人口数量、人均GDP、能源强度、城市化水平每变化1%,江苏省能源消费碳排放量将分别发生3.467%、(0.242+0.024 lnA)%、0.313%和0.151%的变化。在以上研究的基础上,设置8种不同的发展情景,分析了江苏省未来能源消费碳排放量的发展趋势。结果表明,当人口、经济保持低速增长,并保持高技术增长率时,有利于控制江苏省的能源消费碳排放量,2020年江苏省的能源消费碳排放量预测值为202.81 MtC。  相似文献   
999.
Urban carbon footprint reflects the impact and pressure of human activities on urban environment. Based on city level, this paper estimated carbon emissions and carbon footprint of Nanjing city, analyzed urban carbon footprint intensity and carbon cycle pressure and discussed the influencing factors of carbon footprint through LMDI decomposition model. The main conclusions are as follows: (1) The total carbon emissions of Nanjing increased rapidly since 2000, in which the carbon emission from the use of fossil energy was the largest. Meanwhile, carbon sinks of Nanjing presented a declining trend since 2000, which caused the decrease of carbon compensation rate and the increase of urban carbon cycle pressure. (2) The total carbon footprint of Nanjing increased rapidly since 2000, and the carbon deficit was more than ten times of total land areas of Nanjing in 2009, which means Nanjing confronted high carbon cycle pressure. (3) Generally, carbon footprint intensity of Nanjing was on decrease and the carbon footprint productivity was on increase. This indicated that energy utilization rate and carbon efficiency of Nanjing was improved since 2000, and the policy for energy conservation and emission reduction taken by Nanjing's government received better effects. (4) Economic development, population and industrial structure are promoting factors for the increase of carbon footprint of Nanjing, while the industrial carbon footprint intensity was inhibitory factor. (5) Several countermeasures should be taken to decrease urban carbon footprint and alleviate carbon cycle pressure, such as: improvement of the energy efficiency, industrial structure reconstruction, afforestation and environmental protection and land use control. Generally, transition to low-carbon economy is essential for Chinese cities to realize sustainable development in the future.  相似文献   
1000.
Monitoring of subsurface fluid (underground fluid) is an important part of efforts for earthquake prediction in China. The nationwide network, which monitors groundwater level, water temperature, and radon and mercury in groundwater, has been constructed in the last decades. Large amounts of abnormal fluid changes before and after major earthquakes have been recorded, providing precious data for research in earthquake sciences. Many studies have been done in earthquake fluid hydrogeology in order to probe the nature of the earthquake. Much progress in earthquake fluid hydrogeology has been made in the last decades. The paper provides a review of the advances in research on earthquake fluid hydrogeology over the last 40 years in China. It deals with the following five aspects: (1) an introduction to the development history of monitoring networks construction; (2) cases of different subsurface fluid changes recorded before some major earthquakes which occurred in the last decades; (3) characteristics of subsurface fluid changes following major earthquakes; (4) mechanism of subsurface fluid changes before and following earthquakes; (5) application of earthquake fluids in the hydrogeology field.  相似文献   
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