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991.
图像全站仪拓普康GPT-7000 i将数码相机与全站仪有机结合,并且是广焦和长焦两台相机。实现了全站仪测量和数字摄影测量的结合,同时在摄影测量应用之外,为实际测量带来了实实在在的创新和便利。拓普康GPT-7000 i是世界第一台WinCE图像全站仪,相应的机载测量软件和后处理软件与硬件一起构成了一个全新系统,为我们带来了一种新的测量方式和体验。 相似文献
992.
新一轮全球地球化学填图:中国的机遇和挑战 总被引:4,自引:0,他引:4
论述从1988年联合国教科文组织相继批准实施国际地球化学填图(IGCP259)和全球地球化学基准(IGCP360)项目以来,中国和欧洲在制定全球地球化学填图的方法指南及技术标准方面作出的决定性贡献。文中指出,中国的"环境地球化学监控网络及动态地球化学填图"项目、欧洲的FOREGS地球化学基准值填图项目为全球其他国家开展类似工作提供了示范,但地球化学家预期10年内获得全球地表地球化学概貌的愿望至今未能实现。挪威和中国的地球化学家通过IAHS/ICCE正在酝酿"Global geochemical mapping and the sediment-bound flux of major world rivers"重大国际合作项目,以开展新一轮全球地球化学填图。通过国际极地年,IPY317项目首先从北极地区启动。新一轮全球地球化学填图项目计划以中国提出的"全球地球化学填图的泛滥平原沉积物采样草案"和挪威提出的"三角洲中河漫滩沉积物的采样草案"作为实施方案,因而巩固和扩大了中国地球化学填图技术在全球的优势地位。论文在分析中国面临的机遇与挑战后,建议政府主管部门对新一轮全球地球化学填图给予优先支持。 相似文献
993.
Melt glasses for seven types of rock ranging from acid to basic were prepared under 1.0 GPa on a multi-anvil pressure apparatus, YJ-3000 ton press. Densities and elastic properties of the melt glasses were compared with those described in previous studies. It was found that the glasses melted under 1.0 GPa were consistent in density with both naturally-occurring glassy rocks and artificially prepared glasses melted at ambient pressure. The densities of glasses are negatively correlated with the SiO2 contents and positively correlated with the (MgO+FeO) contents. The compressive velocity (Vp) of glass tends to increase with decreasing SiO2 contents and increasing (MgO+FeO) contents. The shear velocity (Vs) of glass tends to increase slightly with increasing SiO2 contents, which has little connection with the (MgO+FeO) contents. It was calculated from densities and velocities that the elastic moduli of glasses are negatively correlated with the SiO2 contents and positively correlated with the (MgO+FeO) contents. 相似文献
994.
Based on the design principles of economic rationality and safety, multiple-pivot pile anchorage approach was used as the supporting engineering of a tall building with a deep foundation ditch. The designs, such as anchor arm, single pile and the whole, were set up in accordance with the calculations of the internal force from the equivalent beam and Yamagata Kunio methods. Moreover, the rationality of the design was estimated using the stability checks. FLAC3D was used for calculating the accuracy of the design. Using FLAC3D to simulating ditch cutting and supporting processes can obtain the equivalent results as the theory analysis in the displacement of ditch surrounding wall, the stress field and stress distribution. 相似文献
995.
Continuous temperature logs to depths between 750 and 1400 m in the Transylvanian Basin, Romania, in many cases show temperature gradient variations with depth which cannot be explained by depth variations in thermal conductivity, topography and ground water flow. The only possible responsible agent seems to be past surface temperature variations. The temperature logs from nine boreholes have been interpreted individually and jointly by least squares inverse modelling with the surface temperature history and background heat flux as unknown parameters. All the temperature profiles are consistent with a temperature rise at the end of the last glaciation. The effects of borehole depth, of a wrong choice of thermal conductivity, and the level of uncorrelated random noise were examined using synthetic examples. 相似文献
996.
997.
西沙群岛晚新生代碳酸盐岩是南海形成演化的产物,它的矿物组成、化学成分和Sr同位素组成可以较好地反映其形成时的古海洋环境.西沙群岛西琛1井是南海最深的全取心钻井,揭示3层白云岩和4层石灰岩.其中.白云岩层具有MgO含量高、Sr总量低的特点,同时出现岩盐、赤铁矿和菱锰矿等指相矿物,反映了古海水盐度较高的氧化环境,对应着三个冰期事件;石灰岩层具有MgO含量低、Sr总量高的特点,同时出现菱铁矿和黄铁矿等指相矿物,反映了古海水盐度较低的还原环境,对应着四个间冰期事件.整体上看,西沙群岛晚新生代碳酸盐岩中Sr的总量和87Sr/86Sr自下而上表现为递增趋势,受控于欧亚和印度板块碰撞引起的青藏高原隆升大的构造背景.但又具有明显的分层性,其中,中-上中新统白云岩层Sr含量偏低,而87Sr/86Sr增加趋势明显,与最大一次冰期事件引起的海退和强烈的白云岩化作用有关;上上新统-全新统石灰岩层Sr总量骤增,87Sr/86Sr明显减小,且变化幅度大,与中新世的白云岩化作用和第四纪幔源岩浆强烈喷发有关. 相似文献
998.
Response of Reactive Phosphorus Burial to the Sedimentary Transition from Cretaceous Black Shales to Oceanic Red Beds in Southern Tibet 下载免费PDF全文
The mechanism of sedimentary transition from the Cretaceous black shales to the oceanic red beds is a new and important direction of Cretaceous research. Chemical sequential extraction is applied to study the burial records of reactive phosphorus in the black shale of the Gyabula Formation and oceanic red beds of the Chuangde Formation, Southern Tibet. Results indicate that the principal reactive phosphorus species is the authigenic and carbonate-associated phosphorus (CaP) in the Gyabula Formation and iron oxides-associated phosphorus (FeP) in the Chuangde Formation which accounts for more than half of their own total phosphorus content. While the authigenic and carbonate-associated phosphorus (CaP) is almost equal in the two Formations; the iron oxides-associated phosphorus is about 1.6 times higher in the Chuangde Formation than that in the Gyabula Formation resulting in a higher content of the total phosphorus in the Chuangde Formation. According to the observations on the marine phosphorus cycle in Modern Ocean, it is found that preferential burial and regeneration of reactive phosphorus corresponds to highly oxic and reducing conditions, respectively, leading to the different distribution of phosphorus in these two distinct type of marine sediments. It is the redox-sensitive behavior of phosphorus cycle to the different redox conditions in the ocean and the controlling effects of phosphorus to the marine production that stimulate the local sedimentary transition from the Cretaceous black shale to the oceanic red beds. 相似文献
999.
LI Guobiao WAN Xiaoqiao JIANG Ganqing HU Xiumian GOUDEM Nicolas HAN Hongdou CHEN Xi 《《地质学报》英文版》2007,81(6):917-924
As one of the mélanges in the southern side of the Yarlung-Zangbo suture zone, the Saiqu mélange in southern Tibet is important for understanding the evolution of the Neo-Tethys ocean. The age of the Saiqu mélange, however, has been debated due to the lack of reliable fossil evidence in matrix strata. Based on lithological similarities with platform strata in southern Tibet and limited fossils from exotic blocks, previous studies variously ascribed the Saiqu mélange to be Triassic in general, Late Triassic, or Late Cretaceous. Here we reported planktonic foraminiferal faunas from the matrix strata of the Saiqu mélange. The new fossils yield a Late Cretaceous age, which is so far the best age constraint for the mélange. Regional stratigraphic correlation indicates that the Cretaceous Oceanic Red Beds (CORBs) in Saiqu may be time equivalent to the CORBs of the Zongzhuo Formation in neighboring regions. Thus the Saiqu mélange should be correlated to the Upper Cretaceous Zongzhuo Formation rather than the Triassic Xiukang Group, as previously suggested. 相似文献
1000.
ZHAO Xi PANG Xiaoping ZHANG Shengli ZHANG Xiang 《地球空间信息科学学报》2007,10(1):75-78
True color image city map is a sort of new-style map which combines the high resolution image and map symbols and shows both advantages in visualization. At the same time, the map unification and harmonization should be taken into account dur-ing the design process, since some visual conflicts appear when map symbols overlaid on the true color image. The objective of this research is to explore the rules in the process of true color image city map design based on chromatic and aesthetic knowledge. At the end, taking the Image Atlas of Guangzhou as an example, image color adjustment, road network presentation, and symbol de-signing issues will be discussed in the application. 相似文献