排序方式： 共有19条查询结果，搜索用时 15 毫秒
1.
Molybdenum disulfide (MoS2), a layered transition-metal dichalcogenide, has been of special importance to the research community of geochemistry, materials
and environmental chemistry, and geotechnical engineering. Understanding the oxidation behavior and charge-transfer mechanisms
in MoS2 is important to gain better insight into the degradation of this mineral in the environment. In addition, understanding the
insertion of metals into molybdenite and evaluation of charge-transfer mechanism and dynamics is important to utilize these
minerals in technological applications. Furthermore, a detailed investigation of thermal oxidation behavior and metal-insertion
will provide a basis to further explore and model the mechanism of adsorption of metal ions onto geomedia. 相似文献
2.
3.
BO Husφy 《极地研究(英文版)》2002,13(1)
1 ＩｎｔｒｏｄｕｃｔｉｏｎＡｔｌａｔｉｔｕｄｅｓａｒｏｕｎｄ 80°Ｎａｎｄｉｎｔｈｅｍｅｓｏｓｐｈｅｒｅ /ｌｏｗｅｒｔｈｅｒｍｏｓｐｈｅｒｅ (ＭＬＴ) ,ｔｈｅｒｅｈａｖｅｂｅｅｎｆｅｗｍｅａｓｕｒｅｍｅｎｔｓｏｆｎｅｕｔｒａｌｄｙｎａｍｉｃｓ.ＡｒｅｑｕｉｒｅｍｅｎｔｗａｓｓｅｅｎｆｏｒｌｏｎｇｔｅｒｍｃｏｎｔｉｎｕａｌｍｏｎｉｔｏｒｉｎｇａｎｄａＶＨＦｍｅｔｅｏｒｒａｄａｒｗａｓｉｄｅｎｔｉｆｉｅｄａｓｂｅｉｎｇａｍｏｓｔｓｕｉｔａｂｌｅｉｎｓｔｒｕｍｅｎｔ.ＲａｄａｒｓｌｉｋｅｔｈｅＥＩＳＣＡ… 相似文献
4.
白云鄂博碳酸岩的方解石-白云石地质温度计 总被引：6，自引：2，他引：4
利用方解石-白云石地质温度计对白云鄂博地区碳酸岩的平衡温度进行了测定。出露于东矿下盘的白云岩质火山岩和出露于尖山的方解石-白云石型火山岩获得了较高的温度,分别为681℃和648℃。这些样品中的方解石呈二十微米左右晶形较完整的小片,被稍大粒度的白云石颗粒包裹,未受交代作用影响,推测这种碳酸岩在快速冷却的情况下保存下了其岩浆侵位时的成分特点,从而指示出接近碳酸岩浆侵位时的温度。但本区多数碳酸岩的平衡温度在400～500℃之间,有下列三种情况:(1)具有自形-半自形中粗粒粒状变晶结构的碳酸岩最后的平衡温度为415～496℃;(2)产自东矿的其余样品(火山岩),所测最后平衡温度为431～485℃,在测温的微区范围内可见极细粒白云石方解石与稀土等矿物共生的现象;(3)为交代重结晶结构的碳酸岩明显受到后期热液流体的交代,在流体的作用下共生方解石和白云石在成分上达到新的平衡,平衡温度为432～507℃。本文所分析的样品多数结果(371～507℃)与用白云石(方解石)和磁铁矿氧同位素温度计对白云鄂博碳酸岩的计算结果(360～546℃)十分一致。虽然有研究者对方解石-白云石温度计用于火成碳酸岩表示过质疑,但本文资料表明火成碳酸岩最后的平衡温度是可以运用方解石-白云石温度计法来计算的。 相似文献
5.
Summary In this paper the results of simulations of air pollution carried out with the mesoscale model system KAMM/DRAIS are presented. They are compared with results of the European scale model EURAD which have been provided by the EURAD-Group, Cologne. With this comparison it is intended to analyse to what extent better resolution of topography and emission data used by the mesoscale model effects the model results. The simulations have been carried out for July 15, 1986, a typical summer day. The model domain contains south-west Germany and part of Alsace with a resolution of 5 km. The emissions for this resolution have been derived by a combination of the coarse EURAD emission data with the data of the TULLA experiment which are available on a much finer grid. The initial and boundary conditions for the species concentrations are determined from the results of the EURAD model. This coupling introduces the long range transport of pollutants into the mesoscale simulation.The meteorological and concentration data of the EURAD model are compared with the corresponding DRAIS model results. The mesoscale flow field is characterized by the channeling along the Upper Rhine Valley, which is not resolved in the EURAD model. The concentration distributions of both models are similar during midday, because of the strong vertical mixing. In the night and especially, in the morning and evening hours the spatial distribution is much better represented by the DRAIS model results. The better resolution of the emissions and the topography in the DRAIS model compared with the EURAD model (80 km grid size) becomes really noticeable. The difference of the ozone concentrations between cities and the, surrounding areas and between the Rhine Valley and the limiting mountains are in the order of 30 ppb as compared to a few ppb in the EURAD simulation. In the morning NO concentrations of about 200 ppb are simulated in the area between Heilbronn and Stuttgart. The EURAD model provides only about 5 ppb. Comparisons with measurements show that the DRAIS simulations are more realistic than the EURAD model results. The features mentioned are also found in an evaluation of the concentration variations in areas corresponding to a grid cell of the EURAD model. Two completely different areas are selected to demonstrate the possible range of the concentration variation. In the area around the City of Stuttgart the ozone concentration in the morning and the evening varies between zero ppb and 50 ppb, approximately. The mean value is nearly the same in both simulations.List of Abbreviations DRAIS
Dreidimensionales Regionales Ausbreitungsund Immissions-Simulationsmodell
- EMEP
European co-operative program for Monitoring and Evaluation of the long-range transmission of air Pollutants
- EUMAC
European Modelling of Atmospheric Constituents
- EURAD
European Acid Deposition Model
- EUROTRAC
EUROpean experiment on TRAnsport and transformation of environmentally relevant trace Constituents in the troposphere over Europe
- JDR
Joint Dry Case
- KAMM
Karlsruher Atmosphärisches Mesoskaliges Modell
- MM4
Mesoscale Model 4
- NCAR
National Center for Atmospheric Research
- RADM
Regional Acid Deposition Model
- TADAP
Transport and Deposition of Acidifying Pollutants
- TULLA
Transport und Umwandlung von Luftschadstoffen im Lande Baden-Württemberg und aus Anrainerstaaten; in English: Transport and Transformation of Air Pollutants in the State of Baden-Württemberg and from neighbouring countries
With 17 Figures 相似文献
6.
安徽巢湖凤凰山剖面石炭系微相和层序地层特征 总被引：9，自引：1，他引：9
应用露头层序地层学基本原理和方法 ,对巢湖凤凰山石炭系剖面进行重新研究。巢湖凤凰山石炭系总厚度为79.0 2 m ,在这个剖面中可以识别出 6种主要岩相、18种微相和 11个三级沉积层序 ,其中六个三级沉积层序属于 I型沉积层序 ,三个属于 II型沉积层序 ,缺失第 9和第 10沉积层序。三级沉积层序在不同的古地理单元和不同的沉积环境中可以进行对比。根据各微相特征和成因 ,揭示了沉积间断面上存在的多期古岩溶现象。阐述了三级层序及其对应的三级海平面升降旋回的特征 相似文献
7.
8.
COSMO-CLM (CCLM) climate simulations over CORDEX-Africa domain: analysis of the ERA-Interim driven simulations at 0.44° and 0.22° resolution 总被引：1，自引：0，他引：1
Hans-Jürgen Panitz Alessandro Dosio Matthias Büchner Daniel Lüthi Klaus Keuler 《Climate Dynamics》2014,42(11-12):3015-3038
We present the results of the application of the COSMO-CLM Regional Climate Model (CCLM) over the CORDEX-Africa domain. Two simulations were performed driven by the ERA-Interim reanalysis (1989–2008): the first one with the standard CORDEX spatial resolution (0.44°), and the second one with an unprecedented high resolution (0.22°). Low-level circulation and its vertical structure, the geographical and temporal evolution of temperature and precipitation are critically evaluated, together with the radiation budget and surface energy fluxes. CCLM is generally able to reproduce the overall features of the African climate, although some deficiencies are evident. Flow circulation is generally well simulated, but an excessive pressure gradient is present between the Gulf of Guinea and the Sahara, related to a marked warm bias over the Sahara and a cold bias over southern Sahel. CCLM underestimates the rainfall peak in the regions affected by the passage of the monsoon. This dry bias may be a consequence of two factors, the misplacement of the monsoon centre and the underestimation of its intensity. The former is related to the northern shift of the West African Heat Low. On the other hand, the underestimation of precipitation intensity may be related to the underestimation of the surface short-wave radiation and latent heat flux. The increase of the model resolution does not bring evident improvements to the results for monthly means statistics. As a result, it appears that 0.44° is a suitable compromise between model performances and computational constrains. 相似文献
9.
Torres MA Testa CP Gáspari C Masutti MB Panitz CM Curi-Pedrosa R de Almeida EA Di Mascio P Filho DW 《Marine pollution bulletin》2002,44(9):923-932
Digestive glands of the mangrove mussel Mytella guyanensis, collected at one non-polluted site (site 1) and two polluted sites (sites 2 and 3), were analysed for different antioxidant defenses, lipid peroxidation and DNA damage. Thiobarbituric acid-reactive substance (TBARS) and 8-oxo-7,8-dihydro-2'-deoxyguanosine levels were enhanced at the polluted sites. With the exception of superoxide dismutase, the activities of catalase and glutathione peroxidase were also higher at the polluted sites. Greater increases were observed in glutathione reductase, glutathione S-transferase and etoxyresorufine-O-deethylase activities at the polluted sites. Conversely, reduced glutathione content was higher at the control site. Trace metal contents in mussels collected at polluted sites were increased compared to the control site, and there were strong positive correlations between TBARS and Cu and Pb contents. M. guyanensis is routinely exposed to an oxidative stress condition at both polluted sites, and considering xenobiotic bioaccumulation in bivalve molluscs, the mangrove mussel represents an excellent bioindicator for environmental monitoring studies. 相似文献
10.
阿拉善变质基底古元古代晚期的构造热事件 总被引：18，自引：7，他引：11
阿拉善地块可分为太古宙的叠布斯格杂岩(岩群)、古元古代的巴彦乌拉山杂岩(岩组)和古-中元古代的阿拉善杂岩(岩群)、波罗斯坦庙片麻杂岩和毕级格台片麻杂岩。太古宙的叠布斯格岩群和片麻岩中的锆石记录了1926Ma和1802Ma的变质事件年龄,角闪石记录了1918Ma的变质事件年龄,斜长石记录了1722Ma的冷却年龄。同时,在波罗斯坦庙变形的片麻状杂岩中的锆石记录了1839Ma的岩浆事件年龄。该区古元古代晚期的构造热事件,可初步将划分为2000～1900Ma的早期事件和1850～1800Ma的晚期事件,并在时间和特点上与大青山-集宁-大同一带变质地体中广泛发育古元古代晚期的岩浆-变质事件非常相似,进而表明,华北克拉通西部陆块中的古元古代晚期造山带(孔兹岩带)向西可延伸到阿拉善东部地区。 相似文献