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21.
Urban heat environmental quality(UHEQ) is affected by the interacting of weather condition and underlying surface framework of urban area .In the last two decades,many researchers from domestic and overseas have studied many problems at the aspect of urban heat environment such as urban heat islands ,urban air temperature and their rela-tion with urban land cover,city population,air pollution etc,In the recent years,Hangzhou,acting as a center city of Zhejiang Province in China,its urbanization quantum and quantity have both changed greatly,in particular ,representing as business affairs building,resident real property and all kins of specialty market having arisen in built-up zone,Based on Landsat TM images data in 1991 and 1999,urban underlying surface temperature value and Normalized Difference Vegetation Index (NDVI) were calculated using image interpreting and supervised classification technique by remote sensing software ERDAS image 8.4,The relation model between urban underlying surface temperature (UUST )and urban air temperature was setup according to the certain correlation patten .Reference to the relational standard of assessing human comfort and other meteorology data of Hangzhou City in summer,the spatial distribution characteristic and the spatial varia-tion degree of human comfort of heat environmental quality are estimated and mapped on a middle scale,that is ,in six districts of Hangzhou City .Then the paper reveals the main characteristic of spatial variation from 1991 to 1999.Lastly,the change mechanism is analyzed and discussed from the viewpoint of city planning,construction and environmental protec-tion.  相似文献   
22.
Urban effects of Chennai on sea breeze induced convection and precipitation   总被引:2,自引:0,他引:2  
Doppler radar derived wind speed and direction profiles showed a well developed sea breeze circulation over the Chennai, India region on 28 June, 2003. Rainfall totals in excess of 100 mm resulted from convection along the sea breeze front. Inland propagation of the sea breeze front was observed in radar reflectivity imagery. High-resolution MM5 simulations were used to investigate the influence of Chennai urban land use on sea breeze initiated convection and precipitation. A comparison of observed and simulated 10m wind speed and direction over Chennai showed that the model was able to simulate the timing and strength of the sea breeze. Urban effects are shown to increase the near surface air temperature over Chennai by 3.0K during the early morning hours. The larger surface temperature gradient along the coast due to urban effects increased onshore flow by 4.0m s−1. Model sensitivity study revealed that precipitation totals were enhanced by 25mm over a large region 150 km west of Chennai due to urban effects. Deficiency in model physics related to night-time forecasts are addressed.  相似文献   
23.
安徽省黄山地区唐家坞组生物地层   总被引:2,自引:0,他引:2  
安徽省南部黄山市刘村一带唐家坞组的时代以往归为晚志留世,新近在唐家坞组中采获腕足类、瓣鳃类、腹足类等多门类化石,并首次采获胞石、鹦鹉螺等化石,其中胞石Conochitina(Densichitana)dens的时代为兰多维列世末至文洛克世初期,含这些化石的层位相当于秀山动物群的层位。结合地质情况分析,唐家坞组时限主要属于早志留世。  相似文献   
24.
藏北南羌塘盆地毕洛错地区下侏罗统曲色组石膏岩层   总被引:1,自引:0,他引:1  
对西藏自治区北部南羌塘盆地毕洛错地区下侏罗统曲色组石膏岩层进行了研究。根据岩石地层和生物地层资料,确认毕洛错地区的石膏岩层和油页岩为曲色组的一部分,地质时代为早侏罗世,并确认下侏罗统曲色组在区域上可能是寻找油气、油页岩资源的重要层位之一。  相似文献   
25.
扬子地区下古生界发育了上奥陶统五峰组和下志留统龙马溪组两套有效烃源岩,查清其发育环境及其控制因素具有重要的科学理论和油气勘探意义.晚奥陶世开始,扬子地区进入碎屑岩陆棚演化阶段;五峰期-龙马溪期,扬子地区主体为局限的深水陆棚环境,总体呈现出浅水陆棚、深水陆棚、次深海共存的古地理格局.沉积体系展布和沉积演化主要受扬子陆块与华夏陆块的汇聚作用控制.扬子地区上奥陶统-下志留统烃源岩的形成与生烃母质生物的高生产力和高埋藏率、冰期-冰后期之交的气温快速转暖、海平面快速上升以及粘土矿物在有机质富集保存过程中的赋存驻留作用等密切相关.  相似文献   
26.
程彦博  毛景文 《地质学报》2008,82(11):1478-1493
在云南个旧地区发育大量与成矿时空密切相关的侵入岩。个旧东区的老厂-卡房花岗质岩体为一隐伏的花岗岩体,侵入于三叠纪个旧组灰岩和碳酸盐地层中,岩性主要为中细粒黑云母花岗岩,是个旧地区与成矿关系最为密切的花岗岩体之一。岩石的ACNK值大多在1.0以上,属于高钾钙碱性系列岩石;U、Th含量较高,应归属于HHP花岗岩;岩石类型属于S型花岗岩,但经历了高度的分异和演化;n(Rb)/n(Sn)- n(Rb)/n(Ba)与n(CaO)/n(Na2O)-n(Al2O3)/n(TiO2)图解均暗示岩石的源区性质为由粘土岩所派生的岩浆。锆石LA-ICP-MS定年结果表明,老厂-卡房岩体形成于85±0.85Ma,相当于晚白垩世。根据区域地质和花岗岩的地球化学特征,暗示个旧地区燕山晚期处于伸展构造背景。  相似文献   
27.
江西省武功山地区浒坑钨矿床的Re-Os年龄及其地质意义   总被引:2,自引:0,他引:2  
刘珺 《地质学报》2008,82(11):1572-1579
浒坑钨矿床是位于江西省中部武功山成矿带的大型石英脉型黑钨矿床。为了确定该矿床的成矿时代,笔者选取了浒坑含钨石英脉中与黑钨矿共生的辉钼矿进行了高精度Re-Os同位素定年,并获得5个辉钼矿样品的Re-Os等时线年龄和模式加权平均年龄分别为150.2±2.2Ma和149.82±0.92Ma。测年数据表明浒坑钨矿床的成矿时代为150Ma左右,是华南地区中生代大规模成岩成矿作用高峰期的产物。辉钼矿含铼较低,表明成矿物质可能来自壳源,与形成浒坑花岗岩体的燕山期重熔S型花岗岩岩浆活动有关。该矿床形成于燕山期岩石圈伸展减薄环境。  相似文献   
28.
The Hong’an area (western Dabie Mountains) is the westernmost terrane in the Qinling-Dabie-Sulu orogen that preserves UHP eclogites. The ages of the UHP metamorphism have not been well constrained, and thus hinder our understanding of the tectonic evolution of this area. LA-ICPMS U–Pb age, trace element and Hf isotope compositions of zircons of a granitic gneiss and an eclogite from the Xinxian UHP unit in the Hong’an area were analyzed to constrain the age of the UHP metamorphism. Most zircons are unzoned or show sector zoning. They have low trace element concentrations, without significant negative Eu anomalies. These metamorphic zircons can be further subdivided into two groups according to their U–Pb ages, and trace element and Lu–Hf isotope compositions. One group with an average age of 239 ± 2 Ma show relatively high and variable HREE contents (527 ≥ LuN ≥ 14) and 176Lu/177Hf ratios (0.00008–0.000931), indicating their growth prior to a great deal of garnet growth in the late stage of continental subduction. The other group yields an average age of 227 ± 2 Ma, and shows consistent low HREE contents and 176Lu/177Hf ratios, suggesting their growth with concurrent garnet crystallization and/or recrystallization. These two groups of age are taken as recording the time of prograde HP to UHP and retrograde UHP–HP stages, respectively. A few cores have high Th/U ratios, high trace element contents, and a clear negative Eu anomaly. These features support a magmatic origin of these zircon cores. The upper intercept ages of 771 ± 86 and 752 ± 70 Ma for the granitic gneiss and eclogite, respectively, indicate that their protoliths probably formed as a bimodal suite in rifting zones in the northern margin of the Yangtze Block. Young Hf model ages (T DM1) of magmatic cores indicate juvenile (mantle-derived) materials were involved in their protolith formation. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   
29.
The analysis of the history of the management and distribution of electricity, water and sanitation networks in Santiago de Chile throws light on a problem which is central to thinking on the relationship between urban services management and territorial splintering: what is the impact of urban policy, in particular housing policy and urban planning, on access to services and on the potential levels of social segregation and institutional splintering of metropolises?The Chilean example is eminently anchored in its political and institutional history. We shall see, for example, that the authoritarian urban policy of the military government, associated with early liberal reform, enabled the improvement of access to networks in every municipality of the Greater Santiago area. However, this success, leading to the integration by urban services of a large territory, does not signify that networks remained neutral as regards the process of spatial segregation. Inversely, we can defend the theory that the presence of an integrated service was a necessary condition and a reinforcing factor of the process of urban spread and residential segregation. This paradoxical argument is a result of the ambivalent liberal network and urban policies of the military government. Urban expansion was largely sustained by the development of integrated infrastructures and universal services. The processes of liberalising land and urban services were mutually sustaining and provided the necessary conditions for the birth of an extremely intense movement of urban sprawl and segregation between 1985 and 2000.  相似文献   
30.
青藏高原拉萨地块西部赛利普地区新生代火山岩依据主量元素可划分为超钾质、钾质和钙碱性系列,主要的岩石类型为粗面安山岩、粗面岩,一个超钾质岩石的40Ar-39Ar年龄为17.58Ma,指示出火山活动为中新世.超钾质、钾质和钙碱性火山岩都显示出富集LREE及LILE(Th、U)、亏损HFSE(Nb、Ta、Ti)的特征.超钾质火山岩具有较高的K2O(6.31%~8.55%)、MgO(6.75%~8.96%)、Cr(270.7×10-6~460.4×10-6)、Ni(142.3×10-6~233.9×10-6)含量,较高的(87Sr/86Sr)i(0.71883~0.72732)和较低的εNd(-14.78~-15.37),指示可能起源于一个前期亏损并经后期俯冲作用改造的富钾的方辉橄榄岩富集地幔源区.钾质火山岩具有比超钾质火山岩低的K2O、MgO、Cr、Ni含量以及高的Ba、Sr含量,初始87Sr/86Sr为0.71553~0.71628,初始143Nd/144Nd为0.51197~0.51198,在空间上与超钾质火山岩共生,可能是前者母岩浆的演化产物.钙碱性火山岩具有较高的Sr(881.7×10-6~1309.2×10-6)、Sr/Y比值(50~108)和较低的Y(12.05×10-6~18.02×10-6),明显亏损重稀土Yb(0.93×10-6~1.30×10-6),类似于典型的埃达克质岩成分特征但相对高钾,并具有相对低的(87Sr/86Sr);(0.70928~0.71374)以及高的εNd(-7.90~-10.91),指示起源于富钾增厚下地壳物质的部分熔融.区域上拉萨地块超钾质岩、钾质岩与N-S向地堑系在空间上共存、时间上相吻合,由此本文认为拉萨地块中新世钾质.超钾质岩和南北向地堑系的形成可能与中新世早期北向俯冲的印度大陆岩石圈断离有关.  相似文献   
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