Study of Sediments in the Yutian-Hotan Oasis, South Xinjiang, China   总被引：2，自引：0，他引：2  

LI Baosheng  David Dian ZHANG  ZHOU Xingjia  ZHU Feng  YUAN Baoyin  MU Guijin  LI Sen  YAN Mancun  JIN Heling  GAO Quanzhou  SUN Wu 《《地质学报》英文版》2002,76(2):221-228

Based on investigation of sediments in the Yutian-Hotan Oasis at the southern margin of the Tarim basin, 14C ages and grain-size and chemical element analyses, the following views are put forward in this paper.(1) Sediments in the Yutian-Hotan Oasis are composed chiefly of "oasis soil", similar to the recent oasis soil, i.e. brown desert soil, which was formed due to pedogenesis after aeolian sand (sandy loam) and dust (loess) of 3.32-6.64 were deposited.(2) The ancient Yutian-Hotan Oasis represented by oasis soil was formed at 13000 a B.P. During the cold period of the past 13000 years, this region is characterized mainly by accumulation of sand and dust storms, and sandy oasis soil was developed in this region due to pedogenesis in an oasis environment; during the warm period, dust falls predominated along with certain current concomitants (lacustrine facies), and silty oasis soil was formed by pedogenesis. Owing to fluctuations of cold and warm climates since 13000 a B.P., sandy oasis soil was deposi  相似文献   

雅鲁藏布江中游下段土地沙漠化成因,趋势及防治对策   总被引：6，自引：6，他引：6  

靳鹤龄  董光荣 《中国沙漠》1997,17(3):255-260

雅鲁藏布江中游下段河谷林芝地区土地沙漠化比较严重，沙漠化土地集中分布于沿江河漫滩和阶地上。在对沙漠化土地类型、分布调查的基础上指出，自然因素是土地沙漠化的基础，处于主导地位，土地资源过度利用加剧了沙漠化的正过程，沙漠化土地在相当一段时间内呈发展的趋势。同时，还提出了土地沙漠化防治的基本对策。  相似文献   

Aeolian Facies Belts in the Taklimakan Desert   总被引：4，自引：0，他引：4  

Li Baosheng  Dong Guangrong  Zhang Jiasheng  Li Sen  Jin Heling  Chen Huizhong  Wen Xiangle  Wang Yao  Lanzhou Desert Research Institute  Chinese Academy of Sciences  Lamhou  Gansuand Zhu YizhiXi''an Open Laboratory of Loess  Quaternary Geology  Chinese Academy of Sciences  Xi''an  Gansu Fei Zhenbi 《《地质学报》英文版》1995,69(3)

At least at the beginning of the last glacial epoch, the facies belts of dune sand, sandy loam and loess formed by winds had existed in the Taklimakan desert and areas south of it. There were no appreciable changes in the NE and NW wind systems and their wind fqrces that deposited dune sand, sandy loam and loess in the global cold stage since the last glacial epoch (accordingly no marked shifts of the boundaries of these aeolian facies belts took place. In the global warm stage since then, the climate in the Taklimakan desert and areas south of it became warm and dry, resulting in ablation of substantial volumes of ice and snow in their surrounding mountains and thus forming alluvial and diluvial deposits in the region. The alluvial-diluvial actions, however, failed to change the general framework of aeolian facies belts.  相似文献   

ASSESSMENT OF A SIMPLE METHOD FOR THE DETERMINATION OF NB AND TA AT THE SUB-μG/G LEVEL IN SILICATE ROCKS BY ICP-MS     

Franck POITRASSON  Christian PIN  Philippe TELOUK  Jean Louis IMBERT 《Geostandards and Geoanalytical Research》1993,17(2):209-215

We report Nb and Ta data for 15 international silicate rock standards, obtained by inductively coupled plasma-mass spectrometry (ICP-MS) measurement following decomposition with HF-HNOs-HCI.⁹⁵ Moand¹⁸⁵Re were used as internal standards, and calibration lines were constructed with artificial solutions. Typical relative standard deviations are better than 10% above 0.2 μg/g, and detection limits for Nb and Ta are 40 and 0.8 ng/g, respectively. The results are generally in good agreement with published data. Moreover, this study points out the Nb-Ta heterogeneity of some standard reference materials on the 100 mg scale.  相似文献   

塔克拉玛干沙漠腹地晚冰期以来的环境与气候变化   总被引：6，自引：1，他引：6  

靳鹤龄  董光荣 《中国沙漠》1994,14(3):31-37

通过对塔克拉玛干沙漠腹地地层剖面的沉积类型、孢粉、ｐＨ值、有机质、ＣａＣＯ＿３和地球化学气候指标Ｃ等分析，认为本区晚冰期以来一直处于荒漠环境，气候变化可划出四个阶段：１３－１０ｋａＢ．Ｐ．气候寒冷。温凉，干旱，湿度相对后期较大；１０－８ｋａＢ．Ｐ．气候温暖干旱，湿度相对减小；８－３ｋａＢ．Ｐ．气候炎热干旱，湿度最小；３ｋａＢ．Ｐ．至今气候温暖干旱，湿度较前增大，气候及环境与今相似。  相似文献   

Geochemical evidence for Holocene millennial-scale climatic and environmental changes in the south-eastern Mu Us Desert,northern China   总被引：3，自引：0，他引：3  

Bing Liu  Heling Jin  Liangying Sun  Zhong Sun  Shuang Zhao 《International Journal of Earth Sciences》2015,104(7):1889-1900

  相似文献   

Formation mechanism and development pattern of aeolian sand landform in Yarlung Zangbo River valley   总被引：1，自引：0，他引：1  

Sen Li  Guangmng Dong  Jianyou Shen  Ping Yang  Xianwan Liu  Yue Wang  Heling Jin  Qiang Wang 《中国科学D辑(英文版)》1999,42(3):272-284

Aeolian sand landforms in the Yarlung Zangbo River valley can be divided into 4 classes and 21 types. The river valley has favourable environment conditions for the development of aeolian sand landforms. Simulation of MM4 mid-scale climate model showed that the near-surface flow field and wind vector field during the winter half year in the river valley are generally favourable for the aeolian sand deposition and as a whole they also affect the distribution mneu and sites of aeolian sand landforms. Sand dunes and sand dune grouup in the river valley developed mainly in three ways, namely windward retarding deposition, leeward back flow deposition and bend circumfluence deposition. Through alternating positive-reverse processes of sand dune formation under wind actions and sand dune vanishing under water actions, sand dunes developed fmm primary zone thmugh main-body zone then to vanishing zone where climbing dunes and falling dunes are declining and are even disappearing. Project supported by the National Natural Science Foundation of China (Grant No. 49471009) and Xi’an State Key Laboratory of Loess and Quaternary Geology (Grant No. 9401)  相似文献   

中国季风边缘区全新世沙地演化及其驱动机制研究进展     

薛文萍  靳鹤龄  刘冰  孙良英  刘振宇 《中国沙漠》2019,39(3):163-171

中国季风边缘区全新世沙地演化和气候变化自东向西具有明显差异性。东部科尔沁沙地、中部毛乌素沙地呈现典型三段式沙地演化过程,西部共和盆地呈现多阶段多反复的沙地演化特征。东部科尔沁沙地、中部毛乌素沙地气候变化也呈现三段式,西部共和盆地由于地域特征气候变化相对复杂。全新世气候突变事件对各区产生差异影响。太阳辐射强度控制的亚洲季风环流和有效湿度变化影响沙地演化过程。  相似文献   

Temperature changes the dynamics of trace element accumulation in Solanum tuberosum L.   总被引：1，自引：0，他引：1  

Yu Li  Qiang Zhang  Runyuan Wang  Xin Gou  Heling Wang  Sheng Wang 《Climatic change》2012,112(3-4):655-672

A simulated warming manipulation was conducted to evaluate the effects of temperature increase on cadmium (Cd), lead (Pb), copper (Cu), iron (Fe) and zinc (Zn) accumulation in Solanum tuberosum L. at Dingxi, Gansu, in the semiarid northwest of China. The objective of this study was to determine if temperature increases significantly changed trace element concentrations and contents in the different ecosystem compartments by affecting soil content, soil solubility and plant capture. The results reveal that an increase in temperature will lead to a significant change in trace element concentrations and contents in Solanum tuberosum L. The strongest effects of a 3°C temperature increase are increased Cu, Zn and Fe leaf concentrations of 25, 27 and 24%, respectively; but decreases in Cd, Pb, Fe, Zn and Cu tuber concentrations of 27, 55, 41, 29 and 23%, respectively. The increasing concentrations of some trace elements in Solanum tuberosum L. leaves are related to greater retranslocation, photosynthetic capacity and growth. Warming decreases the concentrations of some trace elements in tubers, implying that tuber growth rate exceeds its metal uptake rate at higher temperatures. Indeed, it is expected that by the year 2050 the increased temperature will have induced a decrease of concentrations of Cd, Pb, Cu, Fe and Zn of 9.1, 11.5, 18.5, 16.8 and 15.8%, respectively, in tubers in the study area. In addition, the results indicate that a 1–3°C increase in temperature will improve the availability of selected trace elements and transfer potential of these elements from soil to Solanum tuberosum L.  相似文献   

Analysis of the Surface Energy Closure for a Site in the Gobi Desert in Northwest China          下载免费PDF全文

WANG Runyuan  ZHANG Qiang  ZHAO Hong  WANG Heling  WANG Chunling 《Acta Meteorologica Sinica》2012,26(2):250-259

The heat storage terms over an ideal(non-vegetated) horizontal desert surface may be very important and easily neglected in surface energy balance studies.In this paper,based on a field experiment over the Gobi Desert in the middle part of the Hexi Corridor in Northwest China(39 05 N,100 16 E;1457-m elevation),we studied the energy budget closure and evaluated the contribution of the heat storage terms to the closure of the surface energy balance.There were imbalances of 8% and 15% in summer and winter,respectively,if the heat storage terms were not taken into account.For both seasons,a nearly perfect result of the surface energy closure(99%) was obtained by inclusion of the estimates of heat storage terms.The soil heat storage term improved the surface energy imbalance by about 6% in summer and 13% in winter,and the air enthalpy storage term improved it by about 0.6% in summer and 1% in winter,while the contribution of the atmospheric moisture changes could be ignored.  相似文献