Wave-Current Forces on Slender Circular Cylinders

- A series model tests of wave forces by both regular and irregular waves combined with currents on single piles and bipiles in tandem and parallel arrays have been carried out. Based on Morison Equation, linear wave theory and linear wave spectrum theory as well, the characteristics of inline, lift and resultant forces on cylinders have been analyzed respectively. The drag, inertia and lift coefficients CD, CM and CL f皉 single piles related to KC number and the grouping effect coefficients of inline, lift and resultant forces on bipiles in tandem and parallel arrays related to KC number are given in this paper.     

长江口表层沉积物矿物磁性分区特征及其沉积环境指示意义

本研究旨在揭示现代长江口不同沉积环境铁磁性矿物的分布差异,寻找有效识别河口-陆架沉积环境的磁学指标,以便更好地将环境磁学应用于河口古环境研究。在长江口及邻近陆架的6个沉积环境:汊道、拦门沙、三角洲前缘斜坡、前三角洲、前三角洲-陆架过渡区和残留砂区,采集表层沉积物样品,进行粒度和磁性测量。结果显示,χ和SIRM在汊道和拦门沙呈现显著高值,HIRM、χfd%、χARM、χARM/χ和χARM/SIRM在前三角洲和前缘斜坡呈现显著高值,反映了陆源物质输运距离和河口沉积动力对磁性矿物分布的控制作用。因此,参数组合HIRM、χARM、χARM/χ和χARM/SIRM可用于识别全新世地层前缘斜坡和前三角洲-陆架;参数组合χ、SIRM和S-20mT可尝试用于识别汊道和拦门沙环境。     

ANALYSIS OF THE STRATIFICATION FEATURES OF THE YELLOW SEA AND THE LOCATION OF ITS GENERAL SHELF FRONT IN THE WARM HALF-YEAR

A stratification parameter ,defined as theamount of mechanical energy required to bring about vertical mixing, has been calculated for theYellow Sea using available data over the past ten years.T he monthly distributions of Log are obtained to explain the features of the Yellow Sea stratification.Fronts of the shallow shelf sea are often inseparably related with its stratifications. The front of the Yellow Sea in the warm half-year is generated in May and disappears in November. The shelf front moves shoreward and becomes strong in the heating season, but becomes weak in the cooling season upon return.     

Rheological properties of the upper mantle of Northern Eurasia and nature of regional boundaries according to the data of long-range seismic profiles

Deep seismic investigation carried out in Russia in long-range profiles with peaceful nuclear explosions allowed clarifying in details the structure of the upper mantle and the transition zone down to the depth of 700 km within the huge territory of old and young platforms of Northern Eurasia. Variability of horizontal heterogeneity of the upper mantle depending on the depth serves to qualitative estimation of its rheological properties. The upper part of the mantle to the depth of 80–100 km is characterized by the block structure with significant velocity steps of seismic waves at the blocks often divided by deep faults. This is the most rigid part of lithosphere. Below 100 km horizontal heterogeneity is insignificant, i.e., at these depths the substance is more plastic and not capable to retain block structure. On the lithosphere bottom at the depth of 200–250 km plasticity increase is observed as well but the zone of the lower velocities that might have been bound with the area of partial melting (asthenosphere) has not been found. These three layers with different rheological properties are divided by seismic boundaries presented by thin layering zones with alternating higher and lower velocities. At the specified depths any phase boundaries have been distinguished. These thin layering zones are assumed to form due to higher concentration of deep fluids at some levels of depths where mechanical properties and permeability of substance change. Insignificant number of fluids may result in appearance of streaks with partial or film melting at relatively low temperature—to the rise of the weakened zones where subhorizontal shifts are possible. According to seismic data in many world regions seismic boundaries are also observed at the depth of about 100 and 200 km; they may be globally spread. There are signs that areas of xenoliths formation and earthquake concentration, i.e., zones of high deformations, are confined to these depths.     

Low-velocity structure beneath Africa from forward modeling

Seismic waveforms observed in South Africa containing the first arrival crossover of S to SKS (70° to 110°) are analyzed. The data consist of analog records from the World Wide Seismographic Station Network (WWSSN) of deep events beneath South America. The S-waves arrive 2 to 3 s early relative to PREM at ranges from 70° to 95° and then become increasingly delayed, becoming 5 to 6 s late at 110°. The SKS phase is late by 3 to 5 s over the entire range. This pushes crossover between S and SKS, normally observed at about 81°, out about 2° to 3°, which is the most anomalous shift ever reported. To model such features, we modified Grand's tomography model [Grand et al., GSA Today 7 (1997) 1–7], and generated 2D synthetics to match the data. The overall shape and position of the lower mantle low-velocity anomaly proposed by Grand predicts good results if lower mantle anomalies are enhanced to a level of about 4%. This results in a complex tabular structure extending upward from the core–mantle boundary about 1500 km into the mantle. These features appear to be consistent with a large young plume which is erupting off the CMB.     

油企业抗震防灾规划信息管理系统的设计

基于石油企业抗震防灾工作对网络与数据库的信息管理系统的需求，对数据库产品进行了简要分析，并根据石油企业抗震防灾规划的需求和信息管理的一般模式，提出了石油企业抗震防灾规划信息计算机管理系统的设想。认为，以 Ｍｉｃｒｏｓｏｆｔ Ａｃｃｅｓｓ 数据库软件为基础，利用 Ｖ Ｂ或 Ｖ Ｃ等可视化前端应用开发工具，是目前比较好的方案，它将使石油企业抗震防灾规划工作在办公自动化方面迈向新的台阶     

也论二十世纪中国文学发展中的民间文化思潮——兼与高有鹏先生商榷

文学思潮与民间文化都是具有特定内涵的严格概念，与其他思潮既有联系又有区别，民间文化因为自己特殊的存在状态和创造主体而形不成思潮，二十世纪中国文学发展中的五大运动都与民间文化有关，但是不能以民间文化思潮的面目出现。高有鹏先生的《论二十世纪中国文学发展中的民间文化思潮》命题不准确，文中尚有许多可以商榷之处。     

Data analysis of continuous gravitational wave: Fourier transform – II

In this paper we obtain the Fourier Transform of a continuous gravitational wave. We have analysed the data set for (i) a 1-yr observation time and (ii) an arbitrary observation time, for an arbitrary location of detector and source, taking into account the effects arising due to the rotational as well as orbital motion of the Earth. As an application of the transform we considered spin-down and N -component signal analysis.