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72.
湖北省利川市毗邻清江,其下游腾龙洞清江伏流段阻流壅水严重,影响到了城区.本文通过对腾龙洞形态结构特点及其周围地质环境的研究,认为该地下河入口(落水洞)至银河洞尾一段过水断面狭窄,阻流壅水是造成利川市城郊遭受水灾的主要原因.治理时,以隧道加溶洞方案最为经济 相似文献
73.
利用EQIM软件建设和拓展广西地震速报系统 总被引:1,自引:0,他引:1
介绍在全国EQIM软件基础上,结合广西地震台网速报工作的需要,开发适用于广西区域台网内部使用的广西地震速报系统,其基本功能包括:地震速报、信息共享、手机短信发布、Web互联网查询数据资料、数据汇集等多个方面.广西地震速报系统的建立可提高地震速报信息向各级部门的快速传递能力,并为分析预报人员提供及时的地震数据服务. 相似文献
74.
It is a lot limitations to survey and design waterway by the CAD technique,due to timely variation of hydrology and ecology in the complicated estuary area,such as Changjing River estuary.In this paper,the advantages of GIS technique is applied to manage and process the multi kind,multi scale and multi time hydrographic parameters,including water depth,current velocity,tidal,waves,wind speed,temperature and salinity etc.,also to deal with different projection,different scale charts.Meanwhile,in the paper,combination techniques of GIS and CAD has been developed for unification of the charts for efficient management,two-way automatic carts conversion between GIS and CAD,automatic cutting and assemble of a number of Charts,flight path of the projection of spatial data and coordinate transformation.This new technique has been applied to survey and design waterway of Changing River estuary.The result shows that the combination technology of GIS and CAD has application potentiality in the waterway survey and design. 相似文献
75.
Coastline configuration and geomorphologic development mode of arc-shaped coast in South China 总被引:1,自引:0,他引:1
1IntroductionArc-shaped bays are quite common on exposed sediment coast in South China, where the crenulate-bay beaches occur with the presence of two consecutive headlands and a predominant wave approach oblique to the alignment of the upcoast and downcoast headlands (Yasso, 1965). Oblique persistent swell striking a shoreline transports sediment alongshore and sculptures a coast into arc-shaped beaches. The shoreline of beach appearance mainly consists of straight segment and shadow segment… 相似文献
76.
长江口日本沼虾繁殖群体生物学研究 总被引:2,自引:0,他引:2
对2006年6,7,8,10,12月长江口日本沼虾的生殖生物学进行初步研究。测定其头胸甲长、体质量、指节、性腺指数、肝胰腺指数、分析头胸甲长和体质量之间的关系,性腺指数、肝胰腺指数与体质量的相关性。结果表明,日本沼虾主要分布在1.25~2.00mm,体质量分布在2.0~4.0g。头胸甲长与体质量线性相关,指节和头胸甲为正相关,性腺及肝胰腺与体质量及头胸甲长呈正相关,对雌性发育分期进行划分。绝对生殖力4977,相对生殖力1000~2000,雌性生殖力与头胸甲长和体质量正相关,相关方程分别为y=315.47e1.6578x;y=1511.9e0.3251x。 相似文献
77.
Jian Chen Guijian Liu Mengmeng JiangChen-Lin Chou Hui LiBin Wu Liugen ZhengDongdong Jiang 《International Journal of Coal Geology》2011,88(1):41-54
To study the geochemical characteristics of 11 environmentally sensitive trace elements in the coals of the Permian Period from the Huainan coalfield, Anhui province, China, borehole samples of 336 coals, two partings, and four roof and floor mudstones were collected from mineable coal seams. Major elements and selected trace elements were determined by inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), and hydride generation atomic absorption spectrometry (HAAS). The depositional environment, abundances, distribution, and modes of occurrence of trace elements were investigated. Results show that clay and carbonate minerals are the principal inorganic constituents in the coals. A lower deltaic plain, where fluvial channel systems developed successively, was the likely depositional environment of the Permian coals in the Huainan coalfield. All major elements have wider variation ranges than those of Chinese coals except for Mg and Fe. The contents of Cr, Co, Ni, and Se are higher than their averages for Chinese coals and world coals. Vertical variations of trace elements in different formations are not significant except for B and Ba. Certain roof and partings are distinctly higher in trace elements than underlying coal bench samples. The modes of occurrence of trace elements vary in different coal seams as a result of different coal-forming environments. Vanadium, Cr, and Th are associated with aluminosilicate minerals, Ba with carbonate minerals, and Cu, Zn, As, Se, and Pb mainly with sulfide minerals. 相似文献
78.
风对沙漠化过程具有重要影响,起沙风是塑造沙漠地貌格局的主要动力。根据1957-2014年库布齐沙漠周边4个基准气象站的地面风资料,从风速、风向和输沙势等方面分析库布齐沙漠的地面风场特征。结果显示:(1)库布齐沙漠的起沙风频率与平均风速有很高的相关性;(2)年平均风速为2.7 m·s-1,全年盛行风向为WNW-NW,为中等变率锐双峰风况,合成输沙风向约为310°。4月风速最大,为中等变率环境;8月风速较小,为高变率环境;1月风速最小,为低变率环境。3-6月风速最大,风向集中度一般;11月至翌年2月风速较大,风向集中度高;7-10月风速最小,风向集中度差;(3)20世纪80年代中后期和2007年前后风速、起沙风频率和输沙势发生了较大变化,尤其是2007年前后由减小向增大发展;(4)大气环流和地表粗糙度的改变是库布齐沙漠地面风场变化的重要原因。 相似文献
79.
A class of El Nino atmospheric physics oscillation model is considered. The El Nino atmospheric physics oscillation is an abnormal phenomenon involved in the tropical Pacific ocean-atmosphere interactions. The conceptual oscillator model should consider the variations of both the eastern and westem Pacific anomaly patterns. An El Nino atmospheric physics model is proposed using a method for the variational iteration theory. Using the variational iteration method, the approximate expansions of the solution of corresponding problem are constructed. That is, firstly, introducing a set of functional and accounting their variationals, the Lagrange multiplicators are counted, and then the variational iteration is defined, finally, the approximate solution is obtained. From approximate expansions of the solution, the zonal sea surface temperature anomaly in the equatorial eastern Pacific and the thermocline depth anomaly of the seaair oscillation for El Nino atmospheric physics model can be analyzed. El Nino is a very complicated natural phenomenon. Hence basic models need to be reduced for the sea-air oscillator and are solved. The variational iteration is a simple and valid approximate method. 相似文献
80.