潜艇指挥台围壳对阻力和伴流场影响数值研究

采用Reynolds平均Navier-Stokes(RANS)方法计算潜艇三维粘性流场,分析潜艇指挥台围壳对潜艇水动力性能的影响.采用全附体SUBOFF模型验证了CFD方法,通过将螺旋桨盘面处的实效伴流场、艇体表面压力分布以及模型总阻力的模拟结果与Taylor船池的实验结果进行对比.比较结果显示CFD计算结果与实验数据具有很好的一致性,表明CFD方法可以用于潜艇指挥台围壳设计的水动力计算.通过数值计算研究指挥台围壳的高度和在艇上的分布位置对其后方的流场、螺旋桨盘面处的伴流场和阻力的影响.     

2000年夏季莱州湾主要观测要素的分布特征

在 2 0 0 0年夏季莱州湾加密大面调查资料的基础上 ,研究了莱州湾海域海水的温度、盐度、溶解氧、浊度、叶绿素、无机氮、磷酸盐和硅酸盐的分布特征 ,初步讨论了它们之间的相互关系。结果表明 ,莱州湾盐度值与以前相比有显著升高 ;叶绿素南部的高值区对应于溶解氧的低值区 ,温度的高值区 ;浊度受黄河径流的影响较大 ;无机氮西部浓度高 ,东部浓度低 ,且相差很大 ;浮游植物生长的限制因素东部与西部海域不同 ,东部为氮限制 ,而西部为磷限制。     

呼图壁地区震源机制解及构造应力场特征分析

基于新疆测震台网记录的数字地震波形,运用CAP方法测定呼图壁地区2010-01-15~2017-01-02共50次MS≥3.0地震的震源机制解,同时结合早期23次MS≥3.0地震的震源机制解数据,应用MSATSI软件反演研究区时空应力场。结果表明,研究区应力结构类型表现为逆断型,整个区域主压应力P轴近NNE向且倾角较小,说明整个呼图壁地区应力场以NNE向水平挤压作用为主要特征。从空间上看,东部的水平挤压作用更为显著;从时间上看,2010~2016年受到更为显著的NNE向应力场控制,反映了研究区在不同时段应力场的调整变化,但没有改变该区域最大主压应力轴呈NNE向的总体特征,说明整个呼图壁地区可能主要受一种较稳定的NNE向应力场控制。     

安塞油田谭家营油区长2油藏剩余油分布规律及潜力研究

以油藏数值模拟方法为主,同时结合综合地质分析方法对安塞油田谭家营油区长2油藏分小层进行了河流相低渗透储层剩余油成因类型、分布规律及剩余油潜力研究。认为井网未控制型剩余油、注采不完善型剩余油、厚油层顶部滞留型剩余油、层间干扰型剩余油是主要的剩余油成因类型;长21-2储量动用程度高,但剩余储量的绝对数较大,仍然是开发的主力层位,长21-3动用程度很低,但由于存在底水,底水锥进严重,需加强动用程度及开发控制。     

3. Solar System Formation and Early Evolution: the First 100 Million Years

The solar system, as we know it today, is about 4.5 billion years old. It is widely believed that it was essentially completed 100 million years after the formation of the Sun, which itself took less than 1 million years, although the exact chronology remains highly uncertain. For instance: which, of the giant planets or the terrestrial planets, formed first, and how? How did they acquire their mass? What was the early evolution of the “primitive solar nebula” (solar nebula for short)? What is its relation with the circumstellar disks that are ubiquitous around young low-mass stars today? Is it possible to define a “time zero” (t ₀), the epoch of the formation of the solar system? Is the solar system exceptional or common? This astronomical chapter focuses on the early stages, which determine in large part the subsequent evolution of the proto-solar system. This evolution is logarithmic, being very fast initially, then gradually slowing down. The chapter is thus divided in three parts: (1) The first million years: the stellar era. The dominant phase is the formation of the Sun in a stellar cluster, via accretion of material from a circumstellar disk, itself fed by a progressively vanishing circumstellar envelope. (2) The first 10 million years: the disk era. The dominant phase is the evolution and progressive disappearance of circumstellar disks around evolved young stars; planets will start to form at this stage. Important constraints on the solar nebula and on planet formation are drawn from the most primitive objects in the solar system, i.e., meteorites. (3) The first 100 million years: the “telluric” era. This phase is dominated by terrestrial (rocky) planet formation and differentiation, and the appearance of oceans and atmospheres.     

解决太阳横向磁场方向测定中180°不确定性的一个方法

本文提出了一种解决太阳横向磁场方向测定中１８０°不确定性的方法。该方法首先将Ｇａｒｙ等提出的方法定量化，客观地确定每一点的横场方向；然后由独立的Ｈ＿α观测或磁场演化历史，分析和确定磁力线的拓扑联接性，对客观确定的横场方向做经验修正。对活动区的应用表明，该方法是一个可供选择的解决横场方向不确定性的有效方法。     

An interpretation of the variations of the magnetic core-mantle coupling torques and the core drift rate

The influence of recently computed axial magnetic core-mantle coupling torques on the Earth's rotation was investigated. These torques derived from poloidal geomagnetic field within the mantle and at the core-mantle boundary are retarding torques. An accelerating torque due to the action of unknown parts of the core field was estimated by inverse solution of the equation of the mantle rotation for the periodic variations of the quantities of the magnetic field and the length of day. The variations of the drift rate of the Earth's core were compared with those of the mantle rotation velocity for a force-free Earth. The time constants of the coupling process were estimated and discussed in connection with the magnetic coupling of the mantle with an upper core layer. Der Einfluß kürzlich berechneter axialer Kern-Mantel-Kopplungsmomente auf die Erdrotation wurde untersucht. Diese Lorentz-Drehmomente, abgeleitet vom poloidalen geomagnetischen Feld im Mantel und an der Kern-Mantel-Grenze, sind retardierende Momente. Ein beschleunigendes Drehmoment, das der Wirkung unbekannter Feldanteile zugeordnet wird, wurde durch inverse Lösung der Mantelrotationsgleichung für die periodischen Variationen der Magnetfeldgrößen und der Tageslänge abgeschätzt. Die Variationen der Kerndriftgeschwindigkeit wurden mit denen der Mantelrotationsgeschwindigkeit für eine kräftefreie Erde verglichen. Die Zeitkonstanten des Kopplungsprozesses wurden ermittelt und im Zusammenhang mit der magnetischen Kopplung des Mantels mit einer oberen Kernschicht diskutiert.     

Geo-effectiveness of solar wind extremes

Examples of extreme events of solar wind and their effect on geomagnetic conditions are discussed here. It is found that there are two regimes of high speed solar wind streams with a threshold of ∼ 850 km s^-1. Geomagnetic activity enhancement rate (GAER) is defined as an average increase in Ap value per unit average increase in the peak solar wind velocity (Vp) during the stream. GAER was found to be different in the two regimes of high speed streams with +ve and-ve IMF. GAER is 0.73 and 0.53 for solar wind streams with +ve and -ve IMF respectively for the extremely high speed streams (< 850 km s^-1). This indicates that streams above the threshold speed with +ve IMF are 1.4 times more effective in enhancing geomagnetic activity than those with -ve IMF. However, the high speed streams below the threshold with -ve IMF are 1.1 times more effective in enhancing geomagnetic activity than those with +ve IMF. The violent solar activity period (October–November 2003) of cycle 23 presents a very special case during which many severe and strong effects were seen in the environment of the Earth and other planets; however, the z-component of IMF (Bz) is mostly positive during this period. The most severe geomagnetic storm of this cycle occurred when Bz was positive.     

台湾海峡及其邻区现今构造应力场数值模拟

本文将台湾海峡及其邻区划分为多个具有不同弹性参数的等厚区块,并利用基于弹性理论的有限元数值模型,以GPS观测速度和由震源机制解(FMS)得到的主应力轴方向为约束条件,计算了该研究区的现今构造应力场.结果表明:(1)最大主应力轴在台湾海峡中部和台湾岛弧中部大致为NW-SE向,在东北部呈顺时针旋转,而在南部呈逆时针旋转;(2)研究区水平位移场大致以23°N为界,南强北弱,且在北部呈顺时针旋转,南部呈逆时针旋转;(3)东沙-澎湖-北港隆起因强度大于周边盆地区而成为"阻挡带",导致在其南北出现两个反向的构造逃逸区,并且隆起东南区形变特别强烈,而其西北区则相对较弱.