大展弦比飞翼作战飞机横航向飞行品质特性

基于MIL-STD-1797A飞行品质规范,开展了针对大展弦比飞翼作战飞机滚转轴和偏航轴飞行品质特性的研究.随着控制系统对系统动态特性调节作用的日益增强,由飞机构型所引起的动态响应特性差异已变得越来越小,飞翼飞机的闭环滚转模态、螺旋模态、滚转-螺旋耦合振荡、荷兰滚模态、驾驶员座位处的侧向加速度等均可达到较好的飞行品质,但稳态配平特性主要受构型的影响,不能完全满足飞行品质的要求;分析了大展弦比飞翼作战飞机在快速滚转、侧风起降和非对称推力情形下的对滚转轴和偏航轴操纵效能的要求,由于气动构型和操纵面配置等差异,大展弦比飞翼作战飞机在完成某些飞行任务时对操纵效能的需求与常规构型的飞机存在着较大差异.     

电力市场用户侧保险运作探讨

电力市场风险涉及发电侧、电网侧和用户侧三个方面,而解决这些风险的一个强有力的手段就是保险。然而目前保险机构针对发电侧和电网侧的风险推出了相应的解决办法,但是针对用户侧风险却没有成熟的解决方法。基于保险理论,讨论了建立电力市场用户侧保险机制的可行性,进而重点探讨了电力市场用户侧保险机制的确立及其保险费率的厘定。最后,通过制定科学的费率,使投保的用户减少因电力市场风险所带来的损失。     

铁路道口报警及控制系统

为了保证道口行车安全,在无人监护道口设置闪光和语音报警及道口横杆控制系统,利用单片机和无线通信技术以实现列车接近道口时,道口报警闪光器和语音扬声器同时报警,并放下道口横杆;列车离开道口时,道口闪光器和语音扬声器同时关闭,并升起道口横杆。在分析和比较几种单片机和传感器的基础上,确定本系统采用MCS51系列低功耗单片机和磁电传感器。     

飞机结构的随机振动疲劳分析方法

飞机使用中经常会遇到因为结构振动而产生的疲劳破坏现象。飞机结构的振动疲劳分析是进行飞机结构动力学设计的重要设计分析手段。本文通过对国内外几十年来形成的主要的振动疲劳分析方法进行了归纳整理,为飞机设计和维修提供振动疲劳的设计与分析技术支持。     

Solar signals in the minimum extreme temperature records in the southern region of the Gulf of Mexico

Minimum extreme temperature series from several meteorological stations of the Gulf of Mexico are spectrally analyzed using the Maximum Entropy Method.We obtained significant periodicities similar to those found in meteorological and solar activity phenomena. This indicates that probably the solar activity signals are present in the minimum extreme temperature records of this Mexican region.     

Which solar EUV indices are best for reconstructing the solar EUV irradiance?

The solar EUV irradiance is of key importance for space weather. Most of the time, however, surrogate quantities such as EUV indices have to be used by lack of continuous and spectrally resolved measurements of the irradiance. The ability of such proxies to reproduce the irradiance from different solar atmospheric layers is usually investigated by comparing patterns of temporal correlations. We consider instead a statistical approach. The TIMED/SEE experiment, which has been continuously operating since February 2002, allows for the first time to compare in a statistical manner the EUV spectral irradiance to five EUV proxies: the sunspot number, the f10.7, Ca K, and Mg II indices, and the He I equivalent width.     

Relation between galactic and solar cosmic radiation at aviation altitude

Cosmic radiation bombards us at high altitude with ionizing particles; the radiation has a galactic component, which is normally dominant, and a component of solar origin. Cosmic ray particles are the primary source of ionization in the atmosphere above 1 km; below 1 km radon is a dominant source of ionization in many areas.     

低压CMOS折叠共源共栅混频器的设计

基于SMIC 0.18μmCMOS工艺,采用一种折叠共源共栅结构,设计实现了一种低压CMOS折叠共源共栅混频器,解决了传统Gilbert混频器中跨导级与开关级堆叠带来的高电源电压问题,以及在跨导级的高跨导、高线性与开关级的低噪声间进行折衷设计的难题.该混频器核心电路尺寸为165μm×75μm,当射频信号、本振信号和中频信号分别为1575.42MHz、1570MHz和5.42MHz时,仿真表明:该混频器转换增益( G_C )为15dB,双边带噪声系数为12.5dB,输入三阶截断点为-0.4dBm,在1.2V的电源电压条件下,功耗为3.8mW,可用于航空航天领域的电子系统中.      

The Physical Foundation of Forecasting Disturbances in the Geospace From Solar Disk Characteristics

The five main types of antisunward propagating energetic fluxes (particles and emission) may be thought of as well established to date, the effects of which lead to a particilar character of disturbance in the near-terrestrial environment (the Earth's magnetosphere, ionosphere and atmosphere). The strongest global restructuring of the magnetosphere and ionosphere is caused by fluxes of relatively dense n of 1-70 cm-3 at the Earth's orbit) Solar Wind (SW) quasi-neutral, low-energy (E ＜ 10 keV) plasma which cause magnetospheric and ionospheric storms lasting 24 hours or longer. For that reason, main attention is given to their study at the initial stage of research. The physical essence of the method of predicting disturbances in the near-terrestrial space environment, the amplitude of which can be expressed in, for example, the Kp index units, involves:(1) identifying all the most geo-effective SW streams of type, (2) determing their sources on the solar disk,and (3) quantifying the correlations between the characteristics of their solar sources with a maximum value of the Kp-index that is caused by the concerned type of SW stream. Semi-phenomenological relations have been obtained, which relate parameters of type SW stream sources to characteristics of geomagnetic storms:storm commencement, the time at which the storm intensity reaches its maximum values, the storm duration,as well as to the storm amplitude expressed in terms of geomagnetic indeces.      

Study of the Enhancement Events of Relativistic Electron at the Geosynchronous Orbit

The high flux of energetic electron on geostationary orbit can induce many kinds of malfunction of the satellite there, within which the bulk-charging is the most significant that several broadcast satellite failures were confirmed to be due to this effect. The electron flux on geostationary orbit varies in a large range even up to three orders accompanied the passage of interplanetary magnetic cloud and the following geomagnetic disturbances. Upon the investigation of electron flux enhancement events, two types of events were partitioned as recurrent events and random ones. Both of the two kinds of events relate to the interplanetary conditions such as solar wind parameters, IMF etc and their evolution characters as well. As for the recurrent events, we found that, (1) all of the events exhibits periodic recurrence about 27 days, (2) significant increase of electron flux relates to interplanetary index and characters of their distribution, (3) the electron flux also has relation to solar activity index. An artificial neural network was constructed to estimate the flux I day ahead. The random electron flux enhancement events are rare and present different distribution figures to the recurrent ones. The figure of the random events and the conditions of their occurrence is also discussed in this paper.