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91.
ZHANG Jing CHEN Yanjing QI Jinping GE Jun State Key Laboratory of Geological Process Mineral Resources China University of Geosciences Beijing China Key Laboratory of Metallogenic Dynamics Guangzhou Institute of Geochemistry the Chinese Academy of Sciences Guangzhou China 《《地质学报》英文版》2009,83(2)
The Tongbai-East Qinling Mountains,an important part of the Central orogenic belt,is one of the most important metallogenic belts in China and contains lots of orogenic-type and VMS-type (Volcanogenic Massive Sulfide type)metallogenic systems.The Dahe and Shuidongling VMS-type Cu-Zn deposits,located in the Erlangping Group in Tongbai and East Qinling Mountains,respectively, show similar geological and geochemical features.The Huoshenmiao Formation in the East Qinling region and the Liushanyan Formation i... 相似文献
92.
陕北煤炭资源可持续发展之开发思路 总被引:25,自引:2,他引:25
论述了陕北煤炭资源主要特点及开发引起的环境问题,从生态环境保护角度探讨了矿区开发的可持续发展问题,认为应该坚持统一规划、合理布局、适度规模、分散开发、就近转化、保水采煤的开采总方针,坚决杜绝小煤窑的滥采乱挖,组建大型集团公司统一开发,作好煤炭液化、气化、水与煤关系的研究工作,确保矿区经济发展与生态环境相协调。 相似文献
93.
Yuejun Wang Guochun Zhao Xiaoping Xia Yanhua Zhang Weiming Fan Chao Li Xianwu Bi Sanzhong Li 《Chemical Geology》2009,266(3-4):240-250
This paper presents the results of an integrated U-Pb detrital zircon geochronology and Si-in-white mica analysis for synorogenic sediments in the Jianghan Basin to the south of the Dabie Orogen. The results provide an improved understanding of the provenance of these sediments and the unroofing pattern of the early Mesozoic Dabie Mountain. Si contents of detrital white micas range from 3.09 to 3.34 atoms pfu for the upper Triassic sandstones whereas 3.06 to 3.59 atoms pfu for the lower and middle Jurassic sandstones. The majority of detrital white micas in the lower Jurassic sandstones is phengitic and originated exclusively from the Dabie high- to ultrahigh- pressure rocks. The U-Pb dating results of the detrital zircons for seven samples suggest that these synorogenic sediments have a significant change of provenance from late Triassic to early and middle Jurassic. For the upper Triassic sandstone, the U-Pb age clusters of these zircons are characterized by ~ 420-450 Ma, ~ 750-820 Ma, ~ 1050-1200 Ma and ~ 2500 Ma with minor Luliangian (~ 1700–2000 Ma) components. In contrast, the zircon ages of the Jurassic sandstones are dominated by the Luliangian (~ 1700–2000 Ma) ages with only minor Caledonian (~ 420-450 Ma) and Greenville (~ 1050-1200 Ma) ages. In combination with other available geological data, it can be concluded that the Dabie HP-UHP rocks might initially be exposed to the surface at the beginning of early Jurassic (~ 190 Ma). The Jiangnan terrain (also named “Jiangnan old continental in Chinese) to the south of the Jianghan basin provided the predominant supply of upper Triassic sediments, whereas the Paleoproterozoic Yangtze crustal materials (overlying the present Dabie Complex at the time) were the important provenance of the Jurassic sediments in the Jianghan basin. 相似文献
94.
为了研究地下全空间感应涡流的传播规律,以及瞬变响应与围岩电阻率和时间的函数关系,采用数值模拟的方法计算了地下全空间响应。将相同时间九种围岩的响应曲线进行拟和,得到了响应与围岩电阻率的关系;在晚期条件下,将围岩响应随时间变化的曲线进行拟和,得到了响应与时间的关系;通过比较全空间与半空间响应的幅值大小,得到二者的比值关系。结果表明:①全空间下涡流环极大值半径小于半空间下涡流环极大值在地面的投影半径;②全空间瞬变电磁响应按围岩电阻率的1.5次幂进行衰减,以及按时间的2.5次幂进行衰减;③全空间响应幅值为半空间响应幅值的1.93倍。 相似文献
95.
基性麻粒岩产于大陆地壳深部,它的研究可以为大陆岩石圈的性质、组成、演化和深部动力学过程提供重要信息。南天山库米什榆树沟地区发育总厚达1000多米的基性麻粒岩构造岩片,走向南东,朝北东推覆。剖面上和石炭纪蛇绿混杂岩共存,并发生了石榴子石的旋转变形和强烈的石英-长石矿物相韧性变形。然而它们的变形条件至今尚未被研究。本文运用透射电镜(TEM)超微组构技术对榆树沟基性麻粒岩中石英和石榴子石进行了详细研究,结果表明,石英中存在着丰富的超显微变形构造,自由位错、亚颗粒和位错网非常发育,这表明研究区基性麻粒岩在折返抬升过程中曾遭受过较强的石英-长石相韧性变形作用;石榴子石中的超微变形构造则极为少见,只在其中发现几根自由位错,并在其颗粒边缘发现少量亚颗粒构造,说明该矿物主体属于脆性变形。这两种矿物变形性质的差异,反映了石榴子石的晶体结构在该条件下比石英更稳定,而且说明石榴子石的变质温度没有超过900℃,也就是说,本区麻粒岩的变质作用并非发生在极高温度的条件下。 相似文献
96.
97.
The discovery by Swift that a good fraction of gamma-ray bursts (GRBs) have a slowly decaying X-ray afterglow phase led to the suggestion that energy injection into the blast wave takes place several hundred seconds after the burst. This implies that right after the burst the kinetic energy of the blast wave was very low and in turn the efficiency of production of γ-rays during the burst was extremely high, rendering the internal shocks model unlikely. We re-examine the estimates of kinetic energy in GRB afterglows and show that the efficiency of converting the kinetic energy into γ-rays is moderate and does not challenge the standard internal shock model. We also examine several models, including in particular energy injection, suggested to interpret this slow decay phase. We show that with proper parameters, all these models give rise to a slow decline lasting several hours. However, even those models that fit all X-ray observations, and in particular the energy injection model, cannot account self-consistently for both the X-ray and the optical afterglows of well-monitored GRBs such as GRB 050319 and GRB 050401. We speculate about a possible alternative resolution of this puzzle. 相似文献
98.
99.
Peng-Xiong Ma Yong-Jie Zhang Ya-Peng Zhang Yao Li Jing-Jing Zang Xiang Li Tie-Kuang Dong Yi-Zhong Fan Shi-Jun Lei Jian Wu Yu-Hong Yu Qiang Yuan Chuan Yue Zhi-Yu Sun 《天文和天体物理学研究(英文版)》2019,(6):63-70
The Plastic Scintillator Detector(PSD) onboard the DArk Matter Particle Explorer(DAMPE)is designed to measure cosmic ray charge(Z) and to act as a veto detector for gamma ray identification.To fully exploit the charge identification potential of PSD and to enhance its capability to identify gamma ray events, we develop an alignment method for the PSD. The path length of a given track in the volume of a PSD bar is derived taking into account the shift and rotation alignment corrections. By examining energy spectra of corner-passing events and fully contained events, position shifts and rotations of all PSD bars are obtained, and are found to be on average about 1 mm and 0.0015 radian respectively. To validate the alignment method, we introduce artificial shifts and rotations of PSD bars into the detector simulation.These shift and rotation parameters can be recovered successfully by the alignment procedure. As a result of the PSD alignment procedure, the charge resolution of the PSD is improved from 4% to 8%, depending on the nuclei. 相似文献
100.
The light curved in the CM field 总被引:1,自引:0,他引:1
In this paper we introduce the CM field in Sections 2 and 3 based on the paper by Wang and Peng (1985), and calculate the light curved in the CM field in Section 4. The result shows thatP makes CM larger than C at
, and smaller at
. Under a special circumstance which source, CM lens, and observer are in the same line, if we get |
0=0
,
and |
=/2
, we can determine theP(M) andQ(M) of the CM lens,M is the mass of the CM lens. 相似文献