青岛机场一次暴雨过程的TBB特征分析

引言青岛夏季南方暖湿空气活跃,北方冷空气南下频繁．两者在此交汇常常出现强烈发展的对流云团,引发强度大、时间短的降水天气．造成严重灾害．因此对青岛的暴雨进行个例研究．总结预报规律是十分有意义的。耿敏等对青岛历年暴雨进行了统计分析,将青岛暴雨过程分为多个类型,作了大量的分析,并总结了关于台风暴雨、气旋暴雨和冷锋暴雨等类型暴雨过程的预报方法。     

太空“千里眼”观全球风云变化

正2017年夏季,北美、澳洲、欧洲等地区以及我国大范围持续高温、干旱,而我国华南及长江中下游地区暴雨频发。严峻形势下,一颗颗被誉为"千里眼"的风云气象卫星时刻紧盯天气变化,为人民的生命财产安全保驾护航。正是基于这些"守护者"的辛勤工作,气象工作者才能完成各种精细监测和及时准确预报,助力防灾减灾和产业应用。2017年7—9月,风云二号F星(FY-2F)启动8次区域观测(华北区域暴雨预报服务、     

NPOESS原定仪器将执行其他任务

据报道：美国家极轨运行环境卫星系统（NPOESS）原计划在21世纪成为下一代监视天气、大气、海洋、陆地及近太空环境的卫星系统,但因严重的成本超支和研发拖期,2010年,美政府重组了该项目。国家海洋大气管理局（NOAA）和国家航空航天局（NASA）开发联合极地卫星系统（JPSS）,覆盖下午的极轨道,国防部开发国防气象卫星系统（DWSS）,覆盖清晨轨道。欧洲气象卫星开发组织继续向美国提供上午数据。     

陕西南部中尺度对流系统发生的环境和条件

引言 1980年,Maddox开创性地发现了中尺度对流复合体MCC,此后国内外的学者对MCS进行了大量的研究,揭示了MCS的发生环境和生成条件。Maddox通过对10个MCC个例的合成分析,得到MCC形成区、成熟区及消亡区的环境形势。他认为,MCC倾向于发生在高层（200hPa）宽广的、相对弱的西风急流的反气旋一侧的右出口区,系统初始形成在通常呈东西向的弱的大尺度锋区附近,在对流层中层（700和500hPa）有弱的短波槽在近于纬向的气流中向东移动,     

俄“布克Ｍ１－２”中程防空导弹系统简介

继“根弗”（SAM-6）中程防空导弹系统的四个系列后，1972年苏联开始研制在低空和中空具有拦截目标速度为830 m/s、距离为30 km，并具有反战术地地导弹能力的“布克”系统（北约命名为“牛虻”，编号SAM-11），现有三个系列。“布克M1-2”是现俄罗斯新一代中程防空导弹武器系统。本文主要介绍该系统的发展概况。 1 研制概况 “布克M1-2”是1994～1997年在“布克M1”系统的基础上进行研制的。研制的主要任务是： *确保在距离20 km内能够拦截“长矛”型战术地地导弹和空射导弹。 *确保在25 km距离之内，能够打击水面舰艇和在15 km内攻击地面目标（停放在机场的飞机、导弹发射装置、大型指挥所等）。 *提高拦截飞机、直升机和巡航导弹（有翼导弹）的效能。空域按射程扩展到45 km，按高度扩展到25 km。 *改进导弹，增大射程（45 km），提高飞行速度（1200 m/s）和高度，增加导弹机动过载（>24 g）。 *制导雷达站的照射器和制导导弹的天线升高到22 m，并装备光学望远镜瞄准装置，以提高对付低空目标和现代巡航导弹的能力，并扩大视距（见图1)。 *在系统配置方面，指挥车最多可配置6个自行火力单元的组合，每个火力单元可以同时对付4个目标。 *系统车底盘采用两种方案：一是传统的履带式底盘；另一种是轮式底盘。 *提高可靠性和系统的数字化程度，改进目标识别系统，提高抗干扰性能。 2 武器系统的组成及其主要性能 “布克M1-2”高机动多用途的中程防空导弹     

双流机场夏季雷暴多谱勒雷达回波特征分析

雷暴是双流机场夏季主要灾害性天气之一。由雷暴引起的颠簸、积冰、电击、冰雹、下击暴流和低空风切变严重威胁着航空运输的安全。而雷暴的形态各异，引起雷暴的天气形势复杂多变，准确预报难度很大。近年来随着科技的发展，多谱勒天气雷达开始运用于天气预报中，多谱勒天气雷达是定量估测区域降水、检测和预警强对流灾害天气的重要手段，为雷暴临近预报提供了有力的保障。然而，用好多谱勒天气雷达是摆在预报员面前的一个重要课题。本文从2006年夏季5-9月（2006年4月4日为初雷，由于资料缺失未包括在内）双流机场36次雷暴的多谱勒雷达回波图像入手，结合天气形势，分析并总结了各种天气形势下多谱勒雷达回波的特征，并重点分析了7月6日雷暴发生时的多谱勒速度回波图像特征，希望对双流机场雷暴的临近预报找到一些实用的方法，以利于实际工作：     

武汉市一次罕见的春末暴雨天气过程分析

2008年5月3日．在500hPa上南支短波低槽以及850hPa切变线的共同作用下,武汉市爆发了一次罕见的大暴雨天气过程。卫星云图显示强降水云团于3日14时（北京时间,下同）左右在鄂西的宜昌附近形成．而后逐渐自西向东移动并不断发展,最终造成了包括武汉在内的江汉平原及鄂东部分地区的暴雨或大暴雨天气。     

写在前面

自1960年美国发射第一颗气象卫星以来,世界各国和组织已发射了150多颗气象卫星,其中极轨气象卫星约占90％,静止气象卫星占10％。 利用静止气象卫星对大气探测具有十分重要的意义。静止气象卫星可对大尺度天气系统,特别是强对流天气,例如强热带风暴、暴雨等,进行动态的、高频次的观测,是其它探测手段所     

创新源于智慧 精品铸就胜势

四川川大智胜软件股份有限公司（证券代码：002253）是中国知名的自主创新型科技企业,公司依托二十年空管领域产品研究开发的丰富经验,研发了国内领先的空中交通流量管理系统及空域管理和评估系统。     

2013年夏季江淮地区高温干旱事件成因分析

本文利用江淮地区1961-2013年逐日逐月气象资料,统计发现该地区2013年夏季平均气温为53年历史同期最高值,降水量却为最少值,40个站出现极端高温天气。研究其天气气候成因:西太平洋副热带高压偏强偏北导致高空辐合、低层辐散,以下沉气流为主;来自海洋的暖湿气流偏少,冷空气南下较弱,不易交汇降水;中纬西太平洋海温偏高有利于副高北抬及其稳定维持。并与历史同期干旱年份进行对比分析,发现副高及西风带系统与江淮夏季高温干旱联系密切。     

Optimal Control of a Programmed Turn of a Spacecraft

A problem of optimal turn of a spacecraft is considered. The time of turn is minimized, as well as the functional having a meaning of the propellant consumption. An analytical solution to the problem stated is derived. It is demonstrated that the solution optimal in this sense belongs to a class of two-impulse controls, under which a spacecraft executes the turn along the trajectory of its free motion. The solution obtained in this paper differs from earlier available solutions considerably. The estimations of the propellant consumption for a realization of the programmed turn are made.     

Motion of a Planet with a Complex Structure

The motion of a planet consisting of a mantle and a core (solid bodies) connected by a viscoelastic layer and interacting with each other and an external point mass by the law of gravitation is considered. The mutual motions of the core and mantle are investigated assuming that the centers of mass of the planet and external point mass moves along undisturbed Keplerian orbits around the common center of mass of the system. The planetary core and mantle have an axial symmetry and different principal moments of inertia, which leads to a displacement of the center of mantle relative to the center of core and to their mutual rotations. The results obtained on the basis of averaged equations are illustrated by the example of the Earth–Moon system.     

一个带间隙连接结构对梁基频漂移影响研究

文章以一端夹支、另一端带套筒连接结构的梁作为研究对象,通过在连接结构中引入间隙非线性因素,分别研究了在连接结构处有无预紧力两种情况时在均布载荷作用下梁的非线性幅频响应。同时,利用改进的振型转化法及连续振型法对系统进行建模,采用伽辽金近似得到系统的非线性受迫振动方程;针对实际算例,用龙格-库塔法得到了其数值解,讨论了此算例梁的频率漂移结果,从而得到了对研究航天器地面振动试验中的频率漂移现象有价值的结论。     

Identification of failures in a set of sensors of a spacecraft

A method to find and identify failures in a spacecraft’s set of sensitive elements that measure vector quantities of different nature is discussed.     

Peristaltic transport of a viscoelastic fluid in a channel

This paper is devoted to the study of the peristaltic transport of viscoelastic non-Newtonian fluids with fractional Maxwell model in a channel. Approximate analytical solutions have been constructed using Adomian decomposition method under the assumption of long wave boundary layer type approximation and low Reynolds number. The effects of relaxation time, fractional parameters and amplitude on the pressure difference and friction force along one wavelength are received and analyzed. The study is limited to one way coupling model with forward effect of the fluid on the peristaltic wall. It is evident from the result that pressure diminishes with increase in relaxation time and the effects of both fractional parameters on pressure are opposite to each other. The influences of these parameters on friction force are opposite to that of pressure.     

某型卫星有效载荷支架振动抑制

某型号卫星的有效载荷支架结构在验收级振动试验时振动超标。在对结构不做大的修改的前提下，采用约束阻尼层用对原结构进行处理。对不同的约束阻尼层方案采用有限元方法进行计算，综合考虑各种影响因素，如阻尼比和附加质量等，得到合理的约束阻尼减振方案，并在结构星上进行试验，确定最终实施方案。实施方案后，正样星在0．1g振动条件下，最大振动幅值下降了22．3％，保证了卫星的顺利发射。该卫星已经成功发射，并且在轨运行正常。该问题的成功解决和解决问题的方法与过程为今后解决类似问题提供了经验。     

Application of a magnetohydrodynamic element in the control loop of a rotating spacecraft with a spike antenna

The problem of stabilization of a rotating spacecraft with a flexible spike antenna located along the axis of spacecraft rotation is considered. A magnetohydrodynamic element is used as a final-control element in the control loop of spacecraft attitude, and the solar direction sensor serves as a measuring device. At the first stage of investigation, the problem of stability is considered for stationary and non-stationary modes of rotation of the spacecraft with a flexible antenna and with a cavity partially filled with a low-viscosity liquid.     

Equilibrium positions of a weight on a cable fixed to a dumbbell-shaped space station moving along a circular geocentric orbit

The motion of a space object in the gravitational field of the Earth is considered. The object consists of an extended space station and a weight, which is free to move along the cable fixed to the ends of the station. It is assumed that the station is composed of two masses coupled by a weightless rod, while the cable is weightless and non-stretched. The equations of motion of such a system are derived for the case when the motion proceeds in a single plane, while the center of mass of the system moves along a circular geocentric orbit. The conditions of the cable tension (conditions of being on tie) are derived. The phase portrait of the weight motion along the cable is constructed when the station is oriented to the attracting center or is perpendicular to this position. The possibility to leave the tie in this case is analyzed. Equilibrium configurations of the system are found, i.e., such motions of the object under consideration at which the weight does not change its position relative to the station. Lyapunov stability of such configurations is analyzed for two situations: when the station is composed of equal masses and when masses at the ends of the station are different. In particular, for the case of different masses it is established that there exist such positions of equilibrium at which the dumbbell is located at an angle to the direction to the attracting center. In some cases these positions can be stabilized (if the weight is fixed on the cable).     

Station keeping of a solar sail around a Halo orbit

Solar sails are a concept of spacecraft propulsion that takes advantage of solar radiation pressure to propel a spacecraft. Although the thrust provided by a solar sail is small it is constant and unlimited. This offers the chance to deal with novel mission concept. In this work we want to discuss the controllability of a spacecraft around a Halo orbit by means of a solar sail. We will describe the natural dynamics for a solar sail around a Halo orbit. By natural dynamics we mean the behaviour of the trajectory of a solar sail when no control on the sail orientation is applied. We will then discuss how a sequence of changes on the sail orientation will affects the sail's trajectory, and we will use this information to derive efficient station keeping strategies. Finally we will check the robustness of these strategies including different sources of errors in our simulations.