王勃滕王阁序滕王阁

对唐初名诗人王勃及其名的骈体散《滕王阁序》作了简要、客观、历史的评介；对滕王阁的过去和现在也作了资料翔实的论述。     

Time-frequency approaches to ISAR imaging of maneuvering targetsand their limitations

Inverse synthetic aperture radar (ISAR) imaging of the noncooperative maneuvering target is a challenging task because of its time variant orientation and rotation velocity which cannot be measured accurately. This correspondence investigates the principles of ISAR imaging of maneuvering targets, and proposes an algorithm for application in situations where the maneuverability is not too severe and the Doppler variation of subechoes from scatterers can be approximated as a first-order polynomial. The imaging results obtained by using real data show the effectiveness of the new method     

激光输能无人机的概念研究

激光输能无人机(UAV)由于飞行高度高和续航时间长等优势得到关注.从激光输能角度,基于无人机质量评估模型,建立了激光辐照功率密度和无人机输出功率以及飞行性能之间的函数关系.以Sky Sailor太阳能无人机为例,计算分析了激光输能无人机和太阳能无人机的升限和飞行包络.结果表明由于激光辐照功率密度大和光/电之间能量转化效率高,与太阳能无人机比较,可携带的有效载荷更大、升限更高、爬升和抗扰能力更强;随着激光辐照功率密度增大,即使电子设备和有效载荷的质量和功耗都增大,飞行包络很宽,同时,飞行速度增大,但实际升限有所降低.     

激光功率密度对纳秒激光烧蚀冲量耦合影响的数值模拟

为研究激光功率密度对纳秒激光烧蚀冲量耦合影响,建立了一个复杂的一维热传导和流体动力学模型。以空间碎片常见材料Al为例,用建立的物理模型数值计算了纳秒脉宽激光烧蚀产生的冲量随时间变化情况,数值结果和已有的实验数据符合较好。数值计算表明:辐照的激光功率密度越高,发生等离子体屏蔽时间越早,等离子体屏蔽越明显,能量利用率越低;随着激光功率密度的逐渐增大,获得的冲量逐渐趋于稳定,冲量耦合系数降低,数值计算结果与Phipps的最优能量耦合规律一致。      

飞机结构强度试验应急载荷限定系统

多轮多支柱起落架飞机主起落架数量较多，试验机及试验设备重量大。试验应急卸载时，试验件和设备重量、以及加载过程中试验件变形所聚集能量快速释放的不协调性易对支持点结构产生较大冲击载荷，且该载荷不可控，影响试验的考核，存在安全隐患。针对多轮多支柱起落架飞机的强度试验要求，设计一种载荷限定系统。在应急卸载或者试验停试情况下，能够为非支持点起落架输出设定载荷，保证应急瞬间所产生的所有载荷按要求分配到所有起落架上，从而防止支持点起落架超载；试验过程中，能够对非支持点起落架施加试验主动载荷。利用仿真软件验证了系统原理的可行性。依据原理设计载荷限定系统，对其结构和工作性能进行应用验证，并在某型飞机全机疲劳试验中进行应用调试，结果表明，该系统完全能够满足试验要求。     

Hierarchical scheduling for real-time agile satellite task scheduling in a dynamic environment

The imaging processes of optical satellites can be easily affected by unexpected environmental changes, such as changes in cloud coverage. Given the difficulty to predict environmental uncertainties, traditional offline scheduling methods need a follow-up re-scheduling process that responds to real-time environmental information. This repetitive scheduling processes make the offline fine scheduling process a waste of computational resources. Additionally, the offline scheduling method is quite complex owing to its lack of a hierarchy mechanism. To solve these problems, we propose a hierarchical scheduling method for the real-time scheduling problem. This method divides the scheduling process into three steps: pre-assignment, rough scheduling, and fine scheduling. A hierarchical scheduling algorithm based on ant colony algorithm is proposed. Tests with 36 scenarios show that the calculation time is efficiently reduced with this new mechanism. With this consideration of the dynamic environment, the re-scheduling process becomes unnecessary, meaning the wasting of computational resources is avoided and the solution profit is improved.     

Simultaneous observations of spread F irregularities over Southeast Asia longitude using Sanya VHF radar,GPS and C/NOFS

Through concurrently measurements by Communication/Navigation Outage Forecasting System (C/NOFS), Sanya VHF radar and GPS ionospheric scintillation receiver on 12 March 2010, five plasma bubbles were found and three of them were observed by all those instruments. Two well-developed plumes with strong backscatter echoes were measured by Sanya radar and their corresponding depletions were observed by C/NOFS in Orbit 10317, 10318 and 10319. Broad plasma depletions resulting from merging process were found in orbit of 10318. The occurrence time and geophysical positions of scintillations correlate well with observations implemented by Sanya VHF radar and C/NOFS. Observations from three types of instrument indicate that the spread F irregularities have distinct scale. There were longitudinal differences between Sanya VHF radar and C/NOFS as irregularities measured, and the eastward drift of developed bubbles are responsible for these differences.     

基于热喷涂技术制备的热障涂层

着眼于热喷涂技术在热障涂层制备方面的研究现状,在分析热障涂层失效原因的基础上,介绍了等离子喷涂技术及冷喷涂技术和在热障涂层结合层和陶瓷层制备方面的研究进展。     

有色噪声作用下的INS/地磁组合导航算法研究

为了克服基本扩展卡尔曼滤波对噪声统计特性的约束,针对地磁测量噪声为有色噪声的特性,基于扩维卡尔曼滤波算法实现了惯性/地磁组合导航算法。分析了分布式组合导航方案的基本原理,在子滤波器观测信息为实测地磁场总强度信息条件下,基于巡航导弹巡航段飞行过程采用基本扩展卡尔曼滤波和扩维卡尔曼滤波算法进行了仿真分析。仿真结果表明,扩维卡尔曼滤波具有较好的稳定性和收敛性,解决了扩展卡尔曼滤波算法的发散问题。