Compositional Study of a Suite of Samples from the 28-t Armanty (Xinjiang) Iron Meteorite     

John T. Wasson  Xinwei Ouyang  Daode Wang 《Meteoritics & planetary science》1988,23(4):365-369

Abstract— Neutron activation analysis of 15 samples from widely separated locations on the surface of the 28-t Armanty (Xinjiang) group-IIIE iron meteorite showed no compositional variations attributable to magmatic fractionation processes such as fractional crystallization. The homogeneity contrasts with that observed in the Cape York IIIAB iron, in keeping with the idea that the latter is an exceptional case. From the maximum compositional gradients we estimate that the radius of the HIE core was > 1 km. One sample taken from a surface formed by fracture associated with its fall to Earth is slightly anomalous in composition; we suspect that this region is near the border between two parental γ crystals and has a high content of minor phases.  相似文献   

Advances in lunar exploration detectors     

胥涛 欧阳自远  李春来徐琳 《中国地球化学学报》2005,24(1):95-100

Due to the rapid development of modern science and technology, many advanced sensors have been put into use to explore our solar system, including the Moon. With the help of those detectors,we can retrieve more information to about the Moon‘ s composition and evolution. The Clementine (January, 1994), Lunar Prospector (January, 1998) and especially Smart-1 ( September, 2003) launched successively have demonstrated the next-generation planet exploration techniques. Now China has decided to send a probe to the Moon. So it is necessary to overview the development of detectors used for the scientific observation of the Moon. In this paper, some main instruments used to acquire geochemistry information are described, which include UV-VIS-NIR CCD imaging spectroscope, neutronray, gamma-ray, and X-ray spectrometers. Moreover, the payloads of China‘ s first lunar satellite are introduced briefly.  相似文献   

Stratigraphical and biological significance of negative carbon isotopic anomalies in the basal Cambrian series of Guizhou Province   总被引：2，自引：0，他引：2  

杨瑞东王世杰  欧阳自远朱立军  姜立君张位华 高慧 《中国地球化学学报》2005,24(2):108-115

The early Early Cambrian strata within the bounds of Guizhou Province are almost predominated by black shale deposition. Recently, however, the authors have found a section consisting of a set of mudstones interbedded with limestones at the basement of the Cambrian at Yingping, Fuquan County,Guizhou Province, which provides favorable conditions for the study of marine geochemical characteristics of the early Early Cambrian. The characteristics of intense negative carbon isotopic anomalies near the Precambrian/Cambrian boundary at Yingping, Fuquan County, Guizhou Province, can be correlated with those of global carbon isotopic anomalies at the same time on a global scale, corresponding to the intense negative carbon isotopic anomalies near the Neoproterozoic/Cambrian boundaries at the bottom of the Xiaowaitoushan Member, Huize, Yunnan Province, at the top of the Tsagaan 0loom Formation of Mongolia and at the top of the Salarmy Gol Formation of Siberia, as well as those observed in southwestern United States, Iran, Amman, Poland, Newfoundland, the Great Britain, Canada, etc. Negative carbon isotopic anomalies can be used as the important basis for the division of the Precambrian/Cambrian boundaries.There have been found 8 m-thick black shales and cherts below the intense negative carbon isotopic anomalies in this profile. In the black shales there have been found large amounts of fossils such as Bradoricla,gernus Archotuba, indicating that during the period of sedimentation of black shales under anaerobic conditions there would be large quantities of organic species living in the sea. But in the section of grayish-green mudstones interbedded with limestones with intense negative carbon isotopic anomalies almost no organic fossil has been found. This may imply that the anaerobic event seems to have little bearing on the mass extinction near the Precambrian/Cambrian boundary, whereas the intense negative carbon isotopic anomaly event appears to be more closely related to the mass extinction occurring near the Precambrian/Cambrian boundary.  相似文献   

基于锥形模型的空间方向查询研究     

夏宇  朱欣焰  苏科华 《地理空间信息》2007,5(3):65-67

分析了基于锥形模型进行空间方向查询的原理,提出应结合不同实际应用领域和针对不同的空间数据特征选择适当的空间方向关系形式化描述模型的思想。按照这种思想,针对全国各省1∶25万县市级行政区划数据,设计并实现了基于八方向锥形模型的空间方向查询,取得了比较好的检索效果。  相似文献   

Research on runoff forecast approaches to the Aksu River basin   总被引：1，自引：0，他引：1  

Ouyang RuLin  Cheng WeiMing  Wang WeiSheng  Jiang Yan  Zhang YiChi  Wang YongQin 《中国科学D辑(英文版)》2007,50(1):16-25

The Aksu River (the international river between China and Kirghiz) has become the main water source for the Tarim River. It significantly influences the Tarim River’s formation, development and evolution. Along with the western region development strategy and the Tarim River basin comprehensive development and implementation, the research is now focused on the Aksu River basin hydrologic characteristic and hydrologic forecast. Moreover, the Aksu River is representative of rivers supplied with glacier and snow melt in middle-high altitude arid district. As a result, the research on predicting the river flow of the Aksu River basin has theoretical and practical significance. In this paper, considering the limited hydrometeorological data for the Aksu River basin, we have constructed four hydrologic forecast approaches using the daily scale to simulate and forecast daily runoff of two big branches of the Aksu River basin. The four approaches are the upper air temperature and the daily runoff correlation method, AR(p) runoff forecast model, temperature and precipitation revised AR(p) model and the NAM rainfall-runoff model. After comparatively analyzing the simulation results of the four approaches, we discovered that the temperature and precipitation revised AR(p) model, which needs less hydrological and meteorological data and is more predictive, is suitable for the short-term runoff forecast of the Aksu River basin. This research not only offers a foundation for the Aksu River and Tarim Rivers’ hydrologic forecast, flood prevention, control and the entire basin water collocation, but also provides the hydrologic forecast reference approach for other arid ungauged basins.  相似文献   

Mafic enclaves at Jiru porphyry Cu deposit, southern Tibet: Implication for the Eocene magmatic-hydrothermal Cu mineralization     

SUN Xiang  ZHENG Youye  WU Song  LI Miao  Ouyang Haitao  GENG Ruirui 《《地质学报》英文版》2013,87(Z1):778-782

  相似文献   

城市道路交通事故时空分布模式分析     

吴瑞龙  朱欣焰  呙维  岳瀚  佘冰 《测绘与空间地理信息》2018,(7):103-106

为分析城市道路交通事故的时空分布模式,本文基于网络空间线性最邻近指数和Knox时空检验方法,对武汉市青山区道路交通事故的热点路段分布以及时空交互模式进行检验。实验结果表明,城市道路交通事故在空间和时空层面均呈现显著聚集分布。事故热点主要分布在主干道和道路交叉口等人流量大和路网密集的区域,显著性时空交互现象发生于近时空区域内。本文结果可为交通事故防控、交通设施优化提供理论参考。  相似文献   

川南地区渐变型盆—山边界条件下龙马溪组页岩气(藏)富集主控因素:构造—沉积分异与差异性演化          下载免费PDF全文

梁霄  徐剑良  王滢  方新焰  赵磊  伍翊嘉  邓宾 《地质科学》2021,56(1):60-081

川南地区龙马溪组全面进入3500 m以浅的页岩气开发、上产关键阶段。油气地质学界长期以来针对页岩岩相、岩石学与孔隙特征等储层静态参数的重视以及对龙一11小层的单一层系开发的局限,对川南地区龙马溪组页岩气整体产能的提高产生了一定制约。回归基础地质本质,采用地质—地球化学综合研究思路,以构造控制下的沉积分异格局为框架,补充完善川南地区笔石生物地层划分体系;依靠多期节理构造与古应力反演等构造解析方法,建立川南渐变型盆—山边界条件下龙马溪组多期构造演化与流体温压模型,明确川南地区复杂构造背景下页岩气差异富集机理。奥陶纪—志留纪之交的“三隆一坳”古构造—沉积分异,控制了川南地区五峰组—龙马溪组优质页岩渐进式发育与分布。在川南—大娄山渐变型盆山结构边界条件下,晚白垩世以来所经历的4期不同应力场构造变形事件,使威远、泸州—大足与长宁—宁西地区五峰组—龙马溪组具有差异性构造变形—抬升剥蚀与演化特征。差异性的埋深—隆升过程,对受埋深与构造热事件控制的页岩有机地球化学特征及流体充注体系产生重要影响。构造—沉积分异、盆山建造与热演化过程,最终控制川南地区五峰组—龙马溪组早期有限聚集—中期相对富集—晚期调整改造的页岩气成藏演化过程。  相似文献   

Revisit of thorium-based dust fluxes and their implications for the iron fertilization hypothesis     

Ouyang  Siqi  Duan  Zhifei  Lin  Weichang  Luo  Yiming 《Journal of Oceanography》2022,78(1):49-62

Journal of Oceanography - Aeolian dust has a crucial impact on the marine carbon cycle, through its leverage on marine export production. To reconstruct dust depositions, 232Th in marine sediment...  相似文献   

The drivers and spatial distribution of economic efficiency in China’s cities     

Cao  Yanni  Wu  Tong  Kong  Lingqiao  Wang  Xuezhi  Zhang  Lufeng  Ouyang  Zhiyun 《地理学报(英文版)》2022,32(8):1427-1450

Journal of Geographical Sciences - This study analyzes cities in China at the prefecture level and above to calculate indices for “urban economic efficiency” (the relationship between...  相似文献