死海（约旦）里散半岛的重磁勘查     

Batay.  A Zoubi  AA 《长春地质学院学报》1996,26(1):71-77

里散半岛位于非洲板块和阿拉伯板块交接处的死海盆地中。该盆地面积大，构造简单且有下沉运动，说明它是一拉张型盆地。由重力异常数据发现死海盆地可划分成沿南北延伸各约３０ｋｍ长的几个块体，里散半岛是其中最深的一个。中生代沉积厚度约６ｋｍ，更新世沉积厚度为９ｋｍ。死海盆地的拉张距离为２０ｋｍ，表明死海盆地的年龄约３．３Ｍａ。里散半岛下部的前寒武纪结晶基底磁化率较高，这与区内延续的构造活动性有关。  相似文献   

地震学家认为加州还会有地震     

布莱.  S 梁凯利 《地震科技情报》1992,(12):14-15

  相似文献   

苏联经济区方案定量研究的经验     

Ю.К.亚厉山德罗夫  B.B.基斯塔诺夫  A.C.爱泼斯坦  刘振东 《地理科学进展》1985,4(1):17-23

通常,经济区划的任务包括以下几个主要阶段:1) 确定作为基础区的地域;2)按照基础区选择区划指标系统及其定量评价;3) 选择区域系统模式;4) 阐明课题建立算法,直接把基础区进行分类计算;5)解释已获得的结果,选出最好的区划方案和有关进一步改善工作方法的结论等等。基础区的范围视所要解决的任务性质而定。  相似文献   

层状铜矿床的金属备源     

A.C.BROWN  高坪仙 《华北地质》1985,(1)

引言含铜页岩型层状铜矿床中,铜沉积定位在早期成岩期的新概念至少从60年代初有了发展,在过去的二十多年,多方面研究确认和加强了这个概念,研究人员现在不得不调查似乎可能的铜的补给来源以及搬运到成岩成矿目前所在地的金属机制,本文试图评述这些金属的某些潜在的来源,应特别强调注意的是在很多情况下,含金属溶液在某些方面肯定与活动裂谷带上升的喷气流体相类似的可能性。  相似文献   

NORTHERN AND SOUTHERN HEMISPHERIC POLAR LOWS——A COMPARATIVE STUDY          下载免费PDF全文

Erik A.Rasmussen 《Acta Meteorologica Sinica》1993,(3)

Northern Hemispheric“polar lows”,i.e.maritime,small,but fairly intense cyclonic systems have been studied formore than two decades.Recently researchers have turned their attention towards the occurrence of polar lows and othersmall-scale cyclonic disturbances on the Southern Hemisphere.In this paper a short account of our present knowledgeof Northern Hemispheric polar lows will be given,followed by some preliminary results of an investigation of the natureand occurrence of polar lows on the Southern Hemisphere.  相似文献   

Effect of Ploughing Depth on the Growth and Yield of Heracleum candicans： a Threatened Medicinal Herb and a Less-explored Potential Crop of the Himalayan Region     

Hemant K. Badola Jitendra S. Butola 《山地科学学报》2005,2(2):173-180

This paper examines the effect of ploughing depths （A -- 60 cm, B -- 45 cm and C -- 30 cm） on the growth and yield of Heracleum candicans Wall （Apiaceae）, a threatened medicinal herb of the Himalayan region. This less-explored plant is being suggested as a potential crop for the mountain agriculture. The study was carried out in an orchard in Himachal Pradesh, India at 2500 m altitude, for two successive growth years. During the first year, all plants remained in juvenile state; in the second year, nearly 65 % plants produced flowers only under 60cm ploughing depth. Among its morphological traits, plant height, collar diameter and aboveground flesh weight were found to be strongly correlated （P 〈 0.01） with the belowground biomass during the first year （r =0.968, 0.925 and 0.973, respectively） and during the second year （r=0.945, 0.928 and 0.775, respectively）. Increase in the ploughing depth was significantly correlated （P〈0.01） with all growth parameters, including the belowground dry weight, marketable portion of the produce. The belowground biomass （commercial yield; 16.28 Qt/hec） at depth A was about 2.6 and 4.7 times higher than those recorded at depths B and C, respectively. The results clearly justify the importance of deep ploughing and this paper strongly recommends it for economically sustainable cropping.  相似文献   

NGC4051短时标光变的多波段同时性观测     

谢光中  鲍梦贤  卢汝为  郝鹏九  程福臻  Martin.S.Elvis 《天文研究与技术》1986,(1)

探索活动星系的快速光变,是研究星系中心致密核结构及辐射机制的强有力手段。NGC4051是在X射线波段具有短时标(分—小时)光变的极少数活动星系之一。为进一验证X射线波段短时标光变的观测结果,也为了探索光学波段是否具有短时标光变及它们的相关性,我们于1985年5月13—15日分别在美国和中国对NGC4051进行了X射线波段及可见光波段的同时性联测。Martin博士和程福臻在美国利用EXOSAT卫星观测了NGC4051的X射线辐射;谢光中等人在云南天文台利用一米RCC望远镜及积分光度计进行了U波段的观测。结果如下:(1)软X射线的流量降低了13倍,而硬X射线的流量已小到探测不到(至少降低了203倍);(2)U波段在13日晚的观测表明NGC4051有一个时标～1200秒、振幅ΔU 0.11(±0.03)的短时标光变。这种光变共有四个事例,且光变曲线十分完整,由于标准误差σ=0.03,可信度已大于3σ。此外,这一结果还与P.E.Marshall等人在X—射线波段所得到的光变时标～1000秒相吻合,这似乎表明两个波段的光变可能具有相关性。  相似文献   

Effect of Counter-Gradient in the Computation of Turbulent Fluxes of Heat and Moisture in a Regional Model     

S. S. Vaidya  V. N. Lykossov  S. S. Singh 《大气科学进展》1993,(1)

The counter-gradient terms in the computations of turbulent fluxes of heat and moisture have been included in the PBL parameterization of a regional model for monsoon prediction. Results show that inclusion of counter-gradient terms has a marginal impact in the prediction of large scale monsoon circulation and rainfall rates.  相似文献   

遥感技术与美国的人口普查     

H.A.莫罗——琼斯  J.F.沃特金斯  林珲 《地理科学进展》1985,4(3):37-43

引言 D.布鲁金尼的论文《可用空间时代技术进行更精确的人口普查》提出了一些有趣的问题。我们为能够在《摄影测量工程和遥感》杂志上看到这篇有关遥感在社会科学领城内的应用的论文而高兴。我们认为只有了解人口普查数据的多种用途之后,再来检验那些改进人口普查的方法才是合适的,众所周知,每十年一次的人口普查数据的精度和完备性并不是没有缺点的。无疑地,许多人口普查人员将首先承认,每次由点数  相似文献   

Socio-economic and Environmental Implications of the Hydroelectric Projects in Uttarakhand Himalaya, India   总被引：1，自引：1，他引：0  

Naresh Rana S.P. Sati Y.P. Sundriyal Madan Mohan Doval Navin Juyal 《山地科学学报》2007,4(4):344-353

This paper deals with detailed analysis of the fiasco created by the Tehri High Dam in Uttarakhand, India, particularly in terms of resettlement and rehabilitation of the local inhabitants. Aspects pertaining to the environmental issues are also discussed. Currently, the river valleys in Uttarakhand state of India are the targets of increasing hydroelectric projects. Virtually all rivers are being exploited for generating environmental friendly power. Having being learned the hard lesson from Tehri Dam, it has been decided to opt for such schemes in which comparatively little submergence and tempering with the fragile eco-systems is involved.However, our observations suggest that even in such schemes if due care is not taken they may turn out to be a failure.  相似文献