南沙永暑礁近海面风的特征分析

选用南沙永暑礁1989年1月到2009年12月的水文气象月报表资料,运用概率统计的方法将风向和风速记录资料进行分析,定义了永暑礁的4个风期,通过风向风速的年内变化分析得出永暑礁盛行风风向在年内变化成顺时针向右偏移;无论是东北季风期,还是西南季风期,盛行风平均风速都大于非盛行风。东北季风期主导风向顺时针偏移时风力减小,西南季风期主导风向顺时针偏移时,到南南西风时最大,在西南风时略有减弱,呈现波状发展趋势。通过引入风速不稳定指数概念,发现永暑礁西南季风期风速变化突然,更不稳定。     

Geoheritage importance of stratigraphic type sections,type localities and reference sites—review,discussion and protocols for geoconservation

Equivalent in principle to type localities and type specimens in biology and paleontology, geological type sections and type localities, whether for sedimentary, metamorphic or igneous units, are critically important sites as long-term reference and research localities and for geo-education of students. Unlike type specimens that are housed in museums or established institutions of learning, most geological type sections and localities are in field settings and, if they are not located in National Parks or other reserves with some legislated protection, run the risk of being destroyed, inundated, buried by earthworks or otherwise modified. The history of the geological sciences in Australia is such that a number of type localities, or stratigraphic type sections, have been destroyed by local government actions, or developers through lack of knowledge of their importance, or lack of knowledge of their existence. Examples of the severe modification or loss of type sections include those of the Maxicar beds, the Tims Thicket Limestone and the Eaton Sand. The UK, a leader in the field of Geoconservation and with a number of global stratotype section and point locations as well as many other type sections identified within its borders, provides models for preserving and managing important geological sites and type sections. Whole-of-government and local governments are involved in the registering and protection of important geological sites. Aspects of the UK model may be adapted to help secure geological type sections and localities in Australia. While some type sections and heritage localities are already protected, to improve the level of protection for more sites we propose a long-term, multi-pronged approach: creation of an inventory of all nominated locations; registration of appropriate sites at Local, State or Federal government levels, where current legislation allows; education of landowners and land managers, both government and non-government to highlight the importance of type sections to science; and securing more geological type sections and localities in some form of reserve.     

Generation of multivariate cross-correlated geotechnical random fields

A geotechnical problem that involves several spatially correlated parameters can be best described using multivariate cross-correlated random fields. The joint distribution of these random variables cannot be uniquely defined using their marginal distributions and correlation coefficients alone. This paper presents a generic methodology for generating multivariate cross-correlated random fields. The joint distribution is rigorously established using a copula function that describes the dependence structure among the individual variables. The cross-correlated random fields are generated through Cholesky decomposition and conditional sampling based on the joint distribution. The random fields are verified regarding the anisotropic scales of fluctuation and copula parameters.     

黄河（山东段）悬河稳定性评价

通过黄河（山东段）悬河稳定性影响因素分析,各河段都有决口失稳的可能。该文从区域地壳稳定性、堤基稳定性、河道稳定性3个方面,采用模糊数学综合评判法进行悬河稳定性评价,对河段可能出现的失稳或决口险点及其可能造成的危害性进行分析和预测,初步确定了10处地质险段。     

呼图壁地震台定点水准异常检测分析与研究

利用呼图壁地震台洞体场地水准二期的比对观测数据、呼图壁场地跨断层水准四期的同时间段观测资料以及1987~2012年大丰跨断层测线的水准观测数据,分析了呼图壁红山地震台洞体场地水准观测成果的变化速率与跨断层水准观测成果的年变速率的差异性,判定原地震台使用的Ni004光学水准仪的可靠性,依据分析结果提出合理建议。并根据大丰跨断层水准观测的历史观测成果和呼图壁洞体场地水准观测比对后的分析结果,初步探索研究跨断层水准在研究区域的地形变特征。     

河南及邻区瑞利波群速度噪声层析成像

本文选取河南及邻区39个宽频带和甚宽频带地震台站记录的2014年1月～2015年12月垂直分量的连续波形资料,通过波形互相关和叠加运算得到台站间的经验格林函数,并用时频分析方法提取了498条瑞利波群速度频散曲线,进而采用噪声层析成像方法反演获得了河南及邻区8～25s的瑞利波群速度分布图像。结果表明,8s周期的群速度分布与地表构造特征密切相关,平原地区表现为低速异常,而基岩出露的山区呈现为高速异常;14s、20s周期的群速度在山区表现的高速异常与8s相似,说明中上地壳与地壳浅部结构有一定的相关性和继承性;8～20s周期的群速度在华北平原地区存在低速异常范围随周期增加而减小的现象。华北平原地区在下地壳表现出的低速异常,可能与大陆地壳减薄有关。大致以太行-武陵重力梯度带为界,下地壳表现出的西部低速、东部至研究区中部高速异常差异,体现了地壳东薄西厚的结构特征。     

北天山地区中强地震前跨断层形变强度异常特征分析

对新疆北天山地区跨断层流动水准观测资料进行整理,利用断层垂直活动速率求解断层形变异常强度值。基于其变化特征与北天山地区中强地震的对比研究发现,研究区域断层活动整体处于断层形变强度趋势增强的背景下,局部断层形变异常强度值超过指标阈值0.6时,可作为北天山地区中强地震的预测依据。     

薄片显微描绘和自动图像分析技术在岩石学定量评价中的应用

用显微镜描绘技术在绘图纸上绘出线条清晰,反差很大的岩石薄片手绘图像,再将手绘图像通过电视摄像机（ＣＣＤ）输入到计算机自动图像系统中处理,可以取得组成岩石主要矿物的密度分布、粒度、形状及空间分布模式,揭示岩石特征,为岩石学定量研究提供参数。     

Hydrodynamic characteristics of ship sections in shallow water with complex bottom geometry

The method of boundary integral equation developed by the authors was applied for computing inertial and damping characteristics of ship sections for the cases of multi-stepped and inclined bottoms. Comparative calculations for three typical ship hull sections were performed and analyzed. The frequency-dependent data computed for these ship sections can be used to assess the bottom geometry's influence onto the ship motions in waves by means of the strip theory. Limiting values of the same characteristics corresponding to the close-to-zero frequency can also be used for estimation of hydrodynamic forces in manoeuvring over shallow and confined waterways.     

世界各国太阳射电望远镜概况

详细汇总了国内太阳射电望远镜的技术性能及原理框图。收集了部分国外太阳射电望远镜技术指标。对射电望远镜系统参数灵敏度、信噪比、交叉计划隔离度的计算方法作了介绍。