战术飞行机动动作仿真设计与实现

针对数据链飞机模拟器中飞行平台轨迹的终端实时显示问题,以飞机动力学运动方程为基础,构建了盘旋机动和斤斗机动过程的轨迹方程,并给出了机动动作设计的一般流程。通过建立基于时间戳的自适应交互多模(AIMM)时延补偿模型,使飞机动作显示与实际作战网络负载下的飞机状态保持同步。最后设定2种机动动作场景,对飞行机动轨迹予以演示，验证了所设计的可视化平台能有效模拟飞机进行盘旋和斤斗机动,实现了地面指挥所对模拟飞机飞行状态的实时监视,为空战仿真模拟训练奠定基础。     

基于Matlab无人机数学模型仿真分析与研究

无人机数学模型的研究和建立是其飞行实时仿真系统和研究其飞行控制律设计的基础,针对某型无人机进行飞机运动方程的建模与仿真研究,建立了飞机六自由度非线性飞行运动学和动力学模型,并在Matlab/SIMULINK软件环境下建立数字仿真模型和线性化模型.飞行仿真模型采用了模块化的设计结构,具有一定的通用性.     

基于机动动作元的敌机战术机动在线识别方法

敌机战术机动动作的在线识别可为空战态势感知、任务规划和辅助决策提供重要参考信息.针对雷达数据不能提供敌机姿态信息,导致战术机动动作难以直接描述的问题,提出了一种基于空战机动动作元的两级识别方法.首先分析了雷达传感器提供的特征信息;其次根据战术动作的航迹曲线,将空战战术动作分解为11种基本的机动动作元,降低了动作描述的复杂度;然后采用随机森林和支持向量机设计了两级识别方法,层级1利用航迹参数识别机动动作元,层级2根据动作元序列和运动参数识别战术动作.通过对仿真飞行数据进行验证,表明机动动作元能有效描述典型机动动作,提出的方法能够实现敌机战术机动的准确在线识别.      

基于MFO-HTN的超视距空战战术机动组合规划

针对超视距空战机动决策问题，提出基于战术机动组合的超视距空战决策模型。首先，利用参数化语言将超视距空战机动描述为两种典型形式，作为超视距空战战术的基本战术动作。其次，引入层次任务规划网络(HTN)模型，利用空空导弹攻击区描述空战态势，构建带参数的空战HTN模型。最后，将机动时间、可发射距离、可发射时间作为目标函数，构建多目标优化模型，采用飞蛾扑火算法对HTN网络参数进行优化求解。仿真实验表明，飞蛾扑火算法能够快速解算当前态势下的最优参数，所得到的空战战术机动序列能够达到战术目的。该算法模型可以为飞行员提供辅助决策，也为研究智能超视距空战提供了新的思路。     

过失速机动的优化

基于飞机质点非线性动力学模型建立了过失速机动的优化模型，并进行了数值优化，其中用罚函数处理约束条件，用共轭梯度法寻优。计算结果表明，近距空战中，进入超大迎角并绕速度欠滚转有利于飞机快速改变航向，过失速机动中应注意能量耗散问题。     

飞机大迎角纵向机动稳定性及通向混沌的道路

基于非线性动力学理论,分析了飞机大迎角纵向机动的稳定性及混沌行为。根据纵向机动的动力学模型,分析了飞机在大迎角状态下的飞行稳定性,通过Lyapunov稳定性原理,给出了不同参数匹配条件下飞机的纵向机动稳定域;以升降舵偏角和质量为系统参数,利用Melnikov方法,研究了飞机纵向机动的混沌运动,得到通向混沌的道路;通过数值仿真得出不同条件下的飞机纵向运动的Lyapunov指数,分析实验结果并对理论推演进行了验证。结果表明:大攻角机动情况下,飞机极易进入混沌状态,造成飞行不稳定甚至导致飞行事故。     

非线性橡胶悬架系统平顺性仿真与试验

基于橡胶元件非线性力学特性试验和悬架减振性能台架试验,建立了工程自卸车平面八自由度集中质量参数模型,该模型包含了刚度立方非线性和阻尼分段非线性.用龙格库塔法求解八自由度强非线性动力学方程并用试验验证了仿真模型的正确性.仿真分析与试验研究都表明橡胶悬架减振特性仍需进一步的优化设计.通过橡胶悬架参数灵敏度分析,确定了橡胶悬架最合适的优化参数;双参数的仿真研究表明在考虑有效约束条件下能优化得到橡胶悬架的最佳值.该研究为非公路车辆橡胶悬架的优化设计奠定了基础.     

基于四元数法飞行运动方程的逆向仿真算法

逆向仿真算法对于已知飞行状态的验证具有重要的意义.为了避免奇异性,采用四元数法构建了飞机的六自由度运动方程,并进行了四元数方程的仿真分析;介绍了逆向仿真算法的思路,讨论了仿真中关键参数的确定方法;对根据三自由度方程建立的飞机规避导弹时的飞行轨迹进行逆向反推,得出了产生此轨迹需要的输入变量的变化过程,将得出的输入变量作用于基于四元数法的六自由度运动方程中,获得其逆向仿真轨迹.通过对逆向仿真轨迹和原轨迹的比较验证了原飞行轨迹的合理性.     

潜游式管道机器人动力学分析

分析了管道机器人在充满液体的管道中运行时的受力状况,在此基础上建立了基于欧拉参数(四元数)的潜游式管道机器人六自由度空间运动的动力学模型。对于在特定的三维弯管道内沿规划路径游动的机器人,通过流体力学仿真软件Fluent计算出机器人的流场阻力并代入该动力学模型,在Mathematica环境下可计算出机器人的受力.利用该模型进行的动力学仿真得到了机器人在确定形状的弯曲管道中游动时所需的驱动力.欧拉参数(四元数)的引入有效地避免了奇异性.     

基于蒙特卡洛树搜索方法的空战机动决策

针对空战中双方的机动决策问题,考虑角度、距离、速度变化以及高度优势函数,以赢取最大空战优势期望为目标,建立了空战双方机动决策模型,并引入蒙特卡洛树搜索方法进行求解,搜索策略采取极大极小搜索算法。针对双机对抗,通过仿真给出空战态势及空战优势变化曲线,结果表明:我机在整个空战过程中绝大部分是处于优势地位的,验证了使用蒙特卡洛树搜索方法进行空战机动决策的可行性,同时对算法的实时性进行了仿真,计算机动动作所用时间众数位于50~100ms区间内,达到了实时性要求。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that