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61.
The Mahu lake, the third deepest lake in China, is located on the west bank of the Jinsha River in Leibo county, Sichuan Province. It is a dammed lake created by an old landslide on the ancient Huanglang river, a tributary on the west bank of the Jinsha River. Previous studies (Wang and Lu in J Mt Res S1:44–47, 2000) suggested that this landslide was caused by an earthquake approximately 372 ka (Middle Pleistocene), during which a few hundreds of million cubic meters of debris were deposited between 1177 and 900 m a.s.l. (above sea level), covering an area of around 15 km2. Our further investigations, including geodetic survey, borehole drilling, and field reconnaissance, combining with five chronological data, have made some new discoveries at this site. First, the toe of the landslide extends from 900 m a.s.l. down to 320 m a.s.l., i.e., the local bed elevation of the contemporary Jinsha River. Second, the area of the landslide deposits is 17.3 km2 with a volume of 2.38 km3, much larger than the previous estimation. Thus, it should be one of the largest known landslides in China. And the lower elevation of the landslide’s toe also rules out the possibility that it is a hanging valley on the ancient Huanglang river. Our work suggests that this landslide was created by five events according to the overlapping characteristics of the deposits and five chronological data, which are old than 52,600 years, old than 16,000 years, old than 15,500 years, 5800 years, and old than 4200 years, respectively. 相似文献
62.
Diapycnal Mixing (DM) within the upper 2000m of the global ocean is calculated by a fine-scale parameterization using the multiyear-mean density gridded product that created by employing all the Argo float observations to date through the recently published equation of seawater TEOS-10. The geographic distribution of Argo-derived DM derived in this study is spatial-dependent and varies with latitude and depth. The magnitude and pattern of DM is favorably validated by comparisons with previous studies. Furthermore, the mixing coefficient tensor K is calculated and analyzed. Components of the tensor fitting for the geopotential coordinate models are also presented. It is found that the tensor components in horizontal direction, Kxx and Kyy, have similar magnitude and distribution pattern. In the vertical, Kzz is enhanced over regions with rough topography and strong wind (e.g., Westerly region), suggesting agreement with previous estimates. This work presents a scheme to estimate the DM and mixing coefficient tensor using Argo observations, and offers a useful Argo-based mixing product for the purpose of promoting the study and modeling of ocean circulation and other processes. 相似文献
63.
Deng Zu-Gan Zhou You-Yuan Liu Yong-Zhen Dai He-Jun 《Astrophysics and Space Science》1986,126(2):301-312
In former works (Zhouet al., 1983, 1985), a quantitative method have been developed to take the selection effects in the identification of emission lines of quasars into account. It was proved that these selection effects may be the cause of the unevenness in the redshift distribution of quasars. The present work is a continuation and development of former works. We use results given by the surveys with same limit-apparent magnitude and choose the quasars whose absolute magnitudes are within a specific range as the analysing samples. Using the method given in the former papers we may find out the evolutionary parameter in an evolutionary law with form of (1+z)
y
from the best fitting between the calculative and observational redshift distribution. The result of analysis shows that the evolutionary law of quasars selected by slitless technique isp =p
0(1 + z)6.5 ± 1 up toz=2.8. This result coincides with and generalizes the earlier result given by other authors. 相似文献
64.
65.
Spectroscopic Study of Natural Diamonds in China 总被引:2,自引:0,他引:2
It has become clear in recent years that the important substitutional impurities in diamond are nitrogen,hydrogen and boron(Bibby,D.M.,1982).The physical and chemical properties of diamond are determined by the content and form of occurence of nitrogen based on which diamonds are generally classified.The well-known experiments concerning the mutual transformation of the forms the origin of diamond.by Evans.T.Et al.(1982) have provided a theoretic basis for the origin of diamond.Since 1979,spectroscopic investigation of natural diamonds from different areas in china has been carried out using UV-visible and IR spectrophotometer,EPR and cathodoluminescence techniques.We have conducted the classification of natural cathodoluminescence techniques.We have conducted the classification of natural diamonds in China and studies on the forms of nitrogen and hydrogen,the radiation damage and their geological implications.Spectroscopic characteristics of natural diamonds in china and their geological implications are discussed in this paper. 相似文献
66.
67.
河西沿祁连山冷凉灌区春小麦气候生态的研究 总被引:7,自引:0,他引:7
河西冷凉灌区春小麦增产潜力大,具有光能丰富、温度适中、光温配合好、降水相对集中、有效风速大等气候优势,它可成为我国又一个小麦高产地区。限制该区春小麦生产潜力发挥的气候因素是分蘖—拔节期的干旱和开花—灌浆期的光照不足。本文还提出了相应的提高气候生产潜力的途径。 相似文献
68.
山西寿阳—阳泉地区石炭—二叠系沉积环境及其沉积特征 总被引:1,自引:0,他引:1
本区石炭—二叠系是在海湾背景下发育的一套由滨海平原—三角洲平原—冲积平原沉积组成的海退层系。主要沉积环境是三角洲平原,其上部为冲积平原包括网状河和辫状河;下部为海湾(或分支间湾)、潮下碳酸盐岩、潮间介壳滩、碎屑岩潮坪及滨海沼泽湿地等。三角洲为河控浅水三角洲。上述沉积环境,随海水退却在时空上具明显的规律性变化。 相似文献
69.
Deng Mingde Cui Chengyu Geng NaiguangComprehensive Observation Brigade SSB Beijing ChinaInstitute of Remote Sensing Application Academia Sinica Beijing ChinaInstitute of Geophysics SSB Beijing China 《中国地震研究》1995,(2)
In this paper,the theory for applying remote sensing to earthquake prediction has been elucidated and an experiment has been made.Through the experiment,it has been found that the characteristics and temperature of infrared radiant of rocks vary as a function of rock stress,the order of magnitude of radiance variation is 10-5(W/cm2 sr um),the amount of variation of the radiant temperature is 0.2℃~0.8℃ and some significant precursor information has been discovered.The experiment has verified preliminarily that the advanced technology of remote sensing can be applied to earthquake prediction. 相似文献
70.
利用曲线拟合的最小二乘法原理,确定砂土在某垂直压力下的抗剪强度与干密度的关系,并绘制曲线图,可避免人工处理数据的随意性,减小了误差。 相似文献