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81.
Su Young Lee Masatsugu Ohnishi Yasuhiro Shibata Makoto Wwatanabe Kenichi Hoshino Mayumi Jige Xiangping Gu Hitoshi Chiba Tamotsu Oomori Kantaro Fujioka Peter A. Rona 《Resource Geology》2001,51(1):63-68
Abstract: Pyrite rich in Zn, up to 3.1 wt%, was found in the TAG active mound of the TAG hydrothermal field, the slow-spreading Mid-Atlantic Ridge at 26°08'N and 44°49'W. The Zn-rich pyrite is characterized by an optical homogeneity, a homogeneous distribution of Zn in the back-scattered electron images, both at a magnification of about 500, a negative correlation between Fe and Zn contents of the pyrite and a rather small unit cell edge (a0 = 5.4117 ± 0.0008Å), strongly indicating that the detected Zn is present in the pyrite in solid solution. Such Zn concentrations are observed exclusively in dendritic pyrite, suggesting that the Znrich pyrite grew from hydrothermal fluids of a high degree of supersaturation due to quenching on the seafloor. 相似文献
82.
This paper systematically summarized the relation of the abnormal change of He and H2 dissolved gasses in deep hot-water well at Beijing No. 2 Cotton Mill and their relation with seismicity of the region. An
empirical formula for the relation of the precursory anomaly of He and H2 gasses with the magnitude and occurrence time of earthquake has been derived. Two events of magnitude greater than 5 in North
China had been successfully predicted by using this formula.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 490–497, 1993. 相似文献
83.
Statistical Properties of the Highest Pulses in Gamma-Ray Bursts 总被引:1,自引:0,他引:1
Yi-Ping Qin En-Wei Liang Guang-Zhong Xie Cheng-Yue SuNational Astronomical Observatories Yunnan Observatory Chinese Academy of Sciences Kunming qinyp@public.km.yn.cnDepartment of Physics Guangxi University Nanning eloy@iaa.esDepartment of Physics Guangdong Industry University Guangzhou 《中国天文和天体物理学报》2003,3(1):38-48
We study the statistical properties of the highest pulses within individual gamma-ray bursts (GRBs). A wavelet package analysis technique and a developed pulse-finding algorithm have been applied to identify the highest pulses from burst profiles observed by BATSE on board CGRO from 1991 April 21 to 1999 January 26. The statistical light curves of the highest pulses in four energy channels have been derived by an aligning method, which illustrate the temporal evolution of the pulse emission. Our result that narrower pulses go with higher energies is consistent with previous findings. By normalizing both the pulse durations and counts to unity, “characteristic” profiles of the highest pulses in the four channels are also derived. The four characteristic profiles are turned out to be almost the same, thus strongly support the previous conclusion that the temporal profiles in different energy channels are self-similar and the previous conjecture on GRB pulses, implying that the emission process is similar at different energies. The cosmological time dilation effect is examined by investigating the relationship between the pulse flux and pulse duration. An anti-correlation between the two was found, which agrees with the expectation of the cosmological time dilation effect. Also, the evolution of the pulse duration with the observational epoch is studied. The result shows that the pulse duration tends to be shorter in later epochs. This trend cannot be explained by the present theoretical models, and may represent a great challenge to current theories. 相似文献
84.
Research on scale effect of histogram 总被引:2,自引:0,他引:2
To describe the spatial relationship among the earth objects compactly, in this paper, we raised the concept of histo-variogram
based on the analysis of the characteristics of other spatial analyzing methods such as variogram, information entropy. And
we also raised a new spatial analysis method of histogram decomposition based on the definition of standing pixel and contour
pixel. At the end of this paper, we demonstrated the characteristics of histo-variogram by two experiments, one for spatial
analysis, the other for image fusion. 相似文献
85.
本文针对新一轮土地利用总体规划修编势在必行的客观现实,在综合评价三明市上一轮规划的基础上,结合三明市国民经济发展实际及国家宏观调控下的土地政策变化趋势,提出了新一轮规划修编基本构想,以更好地发挥规划对三明市社会经济快速持续健康发展的促进作用。 相似文献
86.
87.
The coupled rotation of the inner core 总被引:1,自引:0,他引:1
The rotation of the inner core (IC) is influenced by the rest of the Earth through a number of coupling mechanisms. Among four possible coupling mechanisms, gravitational, pressure, viscous and electromagnetic, the first two torques are dominant. Numerous existing IC gravitational torque estimates have been shown to agree very well with one another Xu & Szeto 1996 ). It is shown in this paper that different estimates of the IC pressure torque are also in good agreement.
The coupled rotation of the IC has been investigated in the frequency domain by several research groups (Mathews et al. 1991a,b; De Vries & Wahr 1991 ; Dehant et al. 1993; Jiang 1993 ). Not all of these efforts obtained two IC-related rotational modes, the inner-core wobble (ICW) and the free-inner-core nutation (FICN). We investigate this problem in the time domain and confirm the existence of the two modes. The periods of ICW and FICN are in good agreement with those obtained by other researchers. In studying the effects of coupling torques on the IC rotational modes we have found that depending on whether the IC net torque is 'restoring' or otherwise, an increased torque magnitude will respectively shorten or lengthen the ICW period. We have also found that the sense of FICN is determined by the orientation of the net coupling torque on the IC. 相似文献
The coupled rotation of the IC has been investigated in the frequency domain by several research groups (Mathews et al. 1991a,b; De Vries & Wahr 1991 ; Dehant et al. 1993; Jiang 1993 ). Not all of these efforts obtained two IC-related rotational modes, the inner-core wobble (ICW) and the free-inner-core nutation (FICN). We investigate this problem in the time domain and confirm the existence of the two modes. The periods of ICW and FICN are in good agreement with those obtained by other researchers. In studying the effects of coupling torques on the IC rotational modes we have found that depending on whether the IC net torque is 'restoring' or otherwise, an increased torque magnitude will respectively shorten or lengthen the ICW period. We have also found that the sense of FICN is determined by the orientation of the net coupling torque on the IC. 相似文献
88.
Li Zhonghua Su Youjing and Liu ZhuyinSeismological Bureau of Yunnan Province Kunming China 《中国地震研究》1998,(4)
Results of analysis of variation of cross fault short-baseline and short-range leveling in Western Yunnan Earthquake Test Site (WYETS), results show that among five observation stations of cross fault short-baseline and short-range leveling in WYETS before the Lijiang MS7.0 Earthquake occurred in February 1996 only Yongsheng observation station (epicentral distance 82 km) located at Chenghai fault shows great variation about one year before the earthquake. And the nearest observation station, Lijiang (epicentral distance 42 km); presents great coseismic variation, but does not show obvious anomalous variation before the earthquake. There are no significant variations related to the earthquake at the other three observation stations. Two methods are used in analysis of the observed data and some valuable results have been obtained. 相似文献
89.
To investigate the distribution and velocity attributes of gas hydrates in the northern continental slope of South China Sea, Guangzhou Marine Geological Survey conducted four-component (4C) ocean-bottom seismometer (OBS) surveys. A case study is presented to show the results of acquiring and processing OBS data for detecting gas hydrates. Key processing steps such as repositioning, reorientation, PZ summation, and mirror imaging are discussed. Repositioning and reorientation find the correct location and direction of nodes. PZ summation matches P- and Z-components and sums them to separate upgoing and downgoing waves. Upgoing waves are used in conventional imaging, whereas downgoing waves are used in mirror imaging. Mirror imaging uses the energy of the receiver ghost reflection to improve the illumination of shallow structures, where gas hydrates and the associated bottom-simulating reflections (BSRs) are located. We developed a new method of velocity analysis using mirror imaging. The proposed method is based on velocity scanning and iterative prestack time migration. The final imaging results are promising. When combined with the derived velocity field, we can characterize the BSR and shallow structures; hence, we conclude that using 4C OBS can reveal the distribution and velocity attributes of gas hydrates. 相似文献
90.
本文提出延边地层区的晚石炭世地层有两种类型:一是原地系统的天宝山组;二是外来岩块,包括原山秀岭组。并建议停止使用山秀岭组一名。 相似文献