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对中坝镇地热井水水源地进行了水文地质调查、分析测试等相关工作,查明了该水源地的水文地质条件及水化学特征。其感官指标、限量元素类别和组分及微生物等均符合国家饮用泉水水质标准。其中,微量元素锶、锂和偏硅酸含量分别为:0.54~0.57 mg/L、0.27~0.31 mg/L、20.80~29.76 mg/L。同时,在"3S"空间分析技术支持和参考相关水源地国家标准下,划分地热井水源地的保护区范围,并提出相关保护建议,以保证泉水的长期开发利用,为该地热井将来的可持续开发利用提供参考依据。  相似文献   
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青藏高原西南部仲巴地区已发现有3处细石器遗存地点,在仲巴地区选取了一个全新世风成沉积剖面进行年代测试分析以及粒度、地球化学元素等环境指标的分析,探讨仲巴地区的人类活动与气候变化及风沙活动的关系,进而推算细石器遗存的时代.8.9~7.3ka BP为气候湿润,风沙活动弱,成壤作用较强的时期,自然资源相对丰富,能够为细石器先民提供良好的狩猎活动条件.到7.3~3.8ka BP时期,气候干燥,风沙活动强,不利于人类活动.因此推测该区细石器遗存的形成时代在8.9~7.3ka BP左右.  相似文献   
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The Zhongba site has been demonstrated to be a location of salt production based on multi-disciplinary research including salt archaeology,environmental archaeology,zooarchaeology,paleobotany,and other natural science examinations.The continuity of salt production from the Han Dynasty to the present day as understood primarily from ancient texts can now be traced back to even earlier times. Based on the characteristics of cultural layer deposits,features,and artifacts,Zhongba can be clearly distinguished from known settlements,and from bronze,iron,pottery and porcelain workshops.According to various natural science examinations,the major impurities in local salt brine are also found in floor features,brine troughs,and rounded bottom pots at the site even though NaCl itself was not preserved.These traces were left over from the salt production process rather than being naturally deposited.Zhongba and its constituent features and artifacts share many common characters with other salt production sites around the world.Consequently,the Zhongba site can be confidently identified as a salt production site where activity continued for several thousand years.The formation of the site cannot be separated from salt production,and it is also highly related to its natural environment.  相似文献   
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Based on the principle that the present is the key to the past, detailed analyses, such as AMS ^14C dating, grain size, component and morphology of heavy minerals, micro-morphology of zircon, Rb/Sr, magnetic susceptibility and total organic carbon (TOC), were conducted to identify paleoflood sediments archived in Zhongba Site. The results indicate that the plaeoflood sediments bear great similarities with modern flood sediments in the following aspects: (1) probability cumulative curves mainly show a pattern of 3-4 segments; (2) grain-size distribution of suspended matter ranges between 3 and 10(I); (3) the sediments are well-sorted, most of which are suspended matter (〉50%); (4) the same species, quantity and morphology of heavy minerals; (5) scanning electronic microscope images show that shapes of zircon are mainly oval and nearly spheral, rounded due to long-distance transport; (6) higher Rb/Sr values (0.55-0.66)than those of sediments from cultural layers (0.03-0.26); (7) magnetic susceptibility values (133.73-433.05 10^-6m^3/kg) are lower than those of sediments from cultural layers (959.25-2442.44 10^-6 m^3/kg); (8) TOC (0.14%- 0.33%) are lower than those of sediments from cultural layers (1.13%-2.95%). Our results demonstrate that, except for the 1981 flood, there are at least six paleoflood events that occurred during the Qing Dynasty, the middle of Song Dynasty, the early Warring States (400BC-350BC), the West Zhou Dynasty (920BC-900BC), the Xia Dynasty (2070BC-1600BC), and the late Neolithic Age (3000BC-2300BC), respectively.  相似文献   
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本文通过对中坝须二、雷三凝析气藏形成条件的研究,表明成熟期的陆源成因油气、不同源的腐泥与腐植型油气混合的混源型油气在-定条件下也能形成凝析气藏,其形成、富集的地质因素是有利于凝析油气体系成生的有机相带,适合凝析气藏形成的温压条件及圈闭、运移、储集条件的时空配置。  相似文献   
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Tian  XiaoSi  Zhu  Cheng  Sun  ZhiBin  Shui  Tao  Huang  YunPing  Flad  Rowan Kimon  Li  YuMei 《科学通报(英文版)》2011,56(2):169-178
Based on AMS 14C dating data, carbon and nitrogen isotope analyses were conducted on mammal bone collagen of deer, cattle and pigs from the Zhongba site in the Three Gorges Reservoir region of the Yangtze River. These analyses were conducted to reconstruct palaeodiets of mammals, palaeoecology, palaeoenviroment and previous human activities in the study area. Results show that the collagen loss of bone did not change the in vivo isotopic composition of carbon and nitrogen stable isotopes, and most of the bone fossils were well preserved. The bone collagen of samples from deer had a mean δ13C of -23.1‰ and a mean δ15N of 4.7‰, suggesting that deer subsisted in a closed habitat and fed on branches and leaves. The bone collagen of cattle had a mean δ13C of –19.6‰ and a mean δ15N of 5.2‰, which indicates that cattle subsisted in an open habitat and fed on grasses and stems. The δ13C values show that both deer and cattle fed on C3 plants and lived in the same ecosystem, but the t-test results show that deer δ13C and δ15N values were both more negative than those of cattle, indicating that they inhabited different niches. The δ13C and δ15N values of cattle partially overlapped those of deer, suggesting some competition in diets between them. The t-tests show that the δ13C and δ15N values of pigs were more positive than those of cattle and deer, which signifies that pigs occupied a higher trophic level compared to cattle and deer. The wide range of pig δ13C values demonstrates that pig trading had been taking place from early Neolithic Age to late Bronze Age. There were no significant differences in deer δ13C and δ15N values among different archaeological periods, making it clear that climatic, ecological and environmental conditions were kept relatively stable from 2200 to 4200 a BP. This stability may have been responsible for the extensive and complete cultural layers at the Zhongba site. The minimum number of samples required to estimate the mean δ13C values of deer, pigs and cattle are 8, 73 and 16, respectively, and for mean δ15N values of deer, pigs and cattle, the minimum numbers are 4, 5 and 6, respectively.  相似文献   
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近年来,四川省凉山州森林火灾频发,导致滑坡和泥石流等次生山地灾害的发生。选择中坝村山火泥石流为对象,结合无人机技术、实地调查、室内分析试验等方法,分析了中坝村拉达沟泥石流的灾害特征、运动学参数及形成机制等。结果表明:拉达沟泥石流容重为1.74 t/m3,属于稀性泥石流;拉达沟泥石流中较大石块的冲击力为284.59 kN,泥石流的流量为89.3~107.16 m3/s,平均流速为8.93 m/s;采用单沟泥石流危险度评价方法求得其危险度为0.218。据此预测了拉达沟在未来爆发泥石流的可能性较小,并提出了几点减灾建议,为山区森林火灾及次生灾害的综合防治提供借鉴。  相似文献   
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