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991.
Neil B. McLaughlin 《山地科学学报》2011,(5)
Geohazards appear to be increasing in frequency globally. It is of necessity to actively manage these natural hazards to minimize loss of life and property. From an early warning perspective, this paper stresses the potential fatal flood hazard represented by the huge volume of water in Tianchi Lake, the unique geography of Changbai Mountain, and the limited flood control ability in the upstream of the Songhua River. Northeast Asian countries should keep a watchful eye on the Changbai volcano cooperatively,... 相似文献
992.
M.D.Koppelman 《中国天文和天体物理学报》2005,5(2):137-143
Several new light minimum times for the eclipsing binary GSC 0445-1993 have been determined from the observations by Koppelman et al. and the orbital period of this system was revised. A photometric analysis was carried out using the 2003 version of the Wilson-Devinney code. The results reveal that GSC 0445-1993 is a W-type eclipsing binary with a mass ratio of q = 0.323(±0.002) and an over-contact degree of f = 22.8%(±4.2%). A small temperature difference between the components of △T = 135 K and an orbital inclination of i = 65.7°(±0.3°) were obtained. The asymmetry of its light curve (i.e., the O'Connell effect) for this binary star is explained by the presence of a dark spot on the more massive component. 相似文献
993.
Lower Permian formations within the Buqingshan Mountains (A'nyemaqen ophiolitic zone, eastern sector of the eastern Kunlun) were formed in the following paleogeodynamic environments (from north to south): (1) shelf and slope of a passive continental margin in a marginal sea; (2) partially Permian metamorphic rocks of subduclion-accretion complexes and volcanogenic rocks of an ensimatic island arc, of the age limited from above by the Asselian - Sakmarian; and (3 ) an island arc slope and oceanic trench. Subduction-accretion complexes and the island arc volcanites are overlain with a sharp angular unconformity by a carbonate-conglomerate sequence, which presents as local molasse of the Early Permian age. Based on fusulinids from the basal limestone, the age of the local molasse is first defined as the Yakhtashian-Bolorian, i.e. Artinskian-Kungurian (?). The thorough investigations revealed that the initial closure of the eastern Paleotethys within the eastern Kunlun corresponded to the Sakmarian-Yakhtashian (Artinskian) boundary, whereas in the western Paleotethys sector (Northern Pamirs) the closure occurred considerably earlier, prior to the Late Bashkirian. Thus, the idea that the Paleotethys in the eastern Kunlun reached its maximum width in the Permian, is highly questionable. During the Early Permian the A'nyemaqen branch of the Paleotethys intensely decreased. Beginning from the Bolorian (Kungurian) and up to the end of the Permian this branch represented its relict in the form of a marginal sea depression. It may be suggested that the Paleotethys closure in the A'nyemaqen took place gradually from the west to the east and covered a long period from the Late Carboniferous to the terminal Early Permian. 相似文献
994.
Jia-Long Wang National Astronomical Observatories Chinese Academy of Sciences Beijing 《中国天文和天体物理学报》2006,(3)
Taking the 13-point smoothed monthly sunspot number, Ri, and the deviation of the 13 associated monthly sunspot numbers from the smoothed one, D_i, as a number-pair describing the global level of sunspot activity, the evolution of the level is statistically studied for the period from the month which is just 48 months before the minimum to the minimum in the descending phase, using the observed data of Solar Cycles 10 to 22. Our results show (1) for 46 months (94%) of the studied 49 months it is found that for a given month, the distribution of the 13 pairs which come from the 13 solar cycles on a log Ri-D_i plane may be fitted by a straight line with a correlation coefficient larger than the critical one at confidence level α= 5%, and for 36 months (73%) the fitting is even better, for α= 1%;(2) time variations of these two parameters and their correlations in the studied period can be described respectively by functions of time, whose main trends may be expressed by a linear or simple curvilinear function; (3) the evolutionary path of the level of sunspot activity may be represented by a logarithmic function as log R_i=0.704 In D_i-0.291. 相似文献
995.
LI Xian-zhou LIU Li-hua YANG He-ting MING Wei-kun FAN Wen College of Material Science Technology Jilin University Changchun Jilin China Chaoyang Science Technology Union Changchun Jilin China 《东北亚地学研究》2005,(Z1)
There are rich natural resources of natural mineral drugs in eastern Jilin Province. Systematic resource investigation can elevate fractional conversion of this area' s mineral drugs resources superiority. Research on natural mineral drugs of this area can upgrade the translation rate of resource superiority and accelerate the development of local medical industry, especially, it can provide scientific data for founding the strategic design of Chinese traditional medicine's trademark of Jilin Changbai Mountain. Since the resource of mineral drugs can not be regenerated, it must be exploited scientifically, utilized reasonably and protected effectively its sustaining application. 相似文献
996.
Jiang-Hua Wu Xiang-Tao He Yang Chen Wolfgang Voges National Astronomical Observatories Chinese Academy of Sciences Beijing jhwu Department of Astronomy Beijing Normal University Beijing Max-Planck-Institut fur Extraterrestrische Physik D- Garching Germany 《中国天文和天体物理学报》2003,(5)
We report the discovery of five Narrow-Line Seyfert 1 galaxies (NLSls) identified from the ROSAT All-Sky Survey bright sources. One of them has a quasar-like luminosity and two, including the quasar-like one, have close companions and/or show interacting features. We calculate the central black hole masses and Eddington ratios for the five NLSls. In combination with the objects of Kaspi et al., we find that NLSls have smaller central black hole masses and higher accretion rate than normal Seyfert 1s. 相似文献
997.
ZHANGXin-tao LIULi GAOYu-qiao SHAOHong-mei SHENGuang-zheng 《东北亚地学研究》2004,7(2):161-164
It was adopted that the fluorescence microscope, Gas-Flow Heating/Freezing System, Laser-Raman Spectroscopy, etc. are the multimedia techniques for analysing fluid inclusions of quartz veins in Budate Group, Hailar Basin. The results show that fluid inclusions in quartz veins are small ( 1~5μm) monophase, two-phase (liquid vapour) aqueous inclusions; the two-phase aqueous inclusions homogcniese to the liquid phase between 120 ~ 180℃, two dominant types for oil inclusions were determined in quartz veins: ① the primary inclusions, almostly gas, measurement by Laser-Raman Spectroscopy show that both gas phase are enriched in CH4 (94.50%~99.25% ) and C6H6 (0.75%~2.70%), under these conditions, inclusions may have come from juvenile fliud followingly the quartz veins formation. While the quartz veins exhibiting different striking luminescence has been proved by cathodoluminescence, it would be impossible to come from the deep magmas and strata. ② aqueous, liquid and two-phase (liquid vapour) oil inclusions, belong to secondary hydrocarbon inclusions. The oil inclusions of this stage represent mainly the large scale of oil accumulation, located within the quartz microfracture. 相似文献
998.
长江三峡水库诱发地震的成因类型 总被引:9,自引:7,他引:2
分析了三峡水库诱发地震的空间分布特征及库水位变化与地震频度、强度的相关性;讨论了微震群的成因类型。其成因类型主要为岩溶陷落型、塌矿型、裂隙(层面)错动型和水诱发作用下的构造型。 相似文献
999.
近20年来,随着CCD和像增强器的发展,小巧灵活的流星视频观测系统在世界上逐渐多了起来.并且,最终将可能逐步取代流星的目视观测和普通照相观测.介绍云南天文台I号流星彗星视频照相系统的研制及其初步观测结果.这一系统由容易转换的5组件构成.用于流星观测的大视场相机的视场约36度,单帧图像可观测到约6等恒星.实测的恒星星等测量精度可达约0.2等.还讨论了视频照相机比传统的感光胶卷照相的长处,以及视频照相系统的改进与发展. 相似文献
1000.
Aref M. O. Al-Jabali 《东北亚地学研究》2004,(2)
IntroductionRockfalls and landslides can be considered as a natural geological phenomena that indicate the move-ment of the rocks and soil/sand. It occurs at the sites of slopes of high mountains cliffs, hanging valleys, rims and faults due to the movemen… 相似文献