多道防线导弹优化部署

现代空袋一般为大规模空袋，单个防空导弹武器系统已不能满足需要，须部署多个导弹武器系统，如何优化部署是是防空作战部署中的重要问题。利用排队论理论和方法，建立了多道防线的导弹优化部署模型。对于两道防线且导弹数目较少时，可采用完全枚举方法；对于导弹数目很大且防线道数多时，可采用遗传算法。遗传算法是一种基于自然选择和遗传法则的优化方法，并给出了具体的例子，实例表明该算法具有较高的计算效率。最后讨论了实战中情况与基本假设不符合时的解决方法。该研究方法为导弹部署优化提供了基本思路。     

High magnetic gradient environment causes alterations of cytoskeleton and cytoskeleton-associated genes in human osteoblasts cultured in vitro

The effects of a high magnetic gradient environment (HMGE) on the cytoskeletal architecture and genes associated with the cytoskeleton in osteoblasts (MC3T3-E1 and MG-63 cells) were investigated using confocal microscopy, real-time polymerase chain reaction (PCR) and atomic force microscopy (AFM). The findings showed that, under diamagnetic levitation conditions, the architecture and average height of the cytoskeleton and surface roughness in osteoblasts were dramatically altered. HMGE affects cytoskeleton arrangement and cytoskeleton-associated gene expression.     

微小型飞行器的神经网络动态逆控制方法

微小型飞行器(MAV)精确的数学模型很难得到,限制了单纯动态逆控制方法的使用,比例-积分-微分(PID)等传统的控制方法已不能满足要求。针对这一问题,研究了应用动态逆控制方法的新途径──神经网络动态逆。选取串接积分器的多层前向神经网络训练飞行控制系统的动态逆模型,并自适应补偿逆误差。用MATLAB的NNCTRL20工具箱并结合NNSYSID20工具箱建立了仿真系统。升降舵和方向舵联合控制转弯。用PID控制器、近似神经网络动态逆模块、在线神经网络补偿器构建了飞行控制系统。仿真结果表明,神经网络动态逆有较强的鲁棒性、稳定性和指令跟随能力,比PID更适合于微小型飞行器的姿态控制。     

大型运载火箭发动机联合摇摆技术研究

以我国新一代大型运载火箭为背景,针对助推器发动机和芯级发动机共同参与姿态控制的特点,进行控制系统频域分析,提出了合成摆角的控制方法,将双输入控制系统简化为单输入系统,提高了设计效率.     

S参数标准的研制和网络分析仪检定

网络分析仪系统是一种宽频段、多参数、并能进行实时测量的大型频域、时域测量系统。主要介绍同轴、波导 S参数标准件的组成、设计方法、研制过程及参数定标的方法。并介绍了双频激光同轴量规计的设计方法、工作原理及利用它对标准件定标的情况。文章中提供了大量的数据 ,详细也列出了标准失配器、标准空气线等 ,S参数标准件在各频率点上定标的数据 ,从各不同方面验证了参数标准的准确性。     

Protostellar Winds and Chondritic Meteorites

We discuss the interaction between the magnetosphere of a young star and its surrounding accretion disk. We consider how an X-wind can be driven magnetocentrifugally from the inner edge of the disk where accreting gas is diverted onto stellar field lines either to flow onto the Sun or to be flung outwards with the wind. The X-wind satisfies many observational tests concerning optical jets, Herbig-Haro objects, and molecular outflows. Connections may exist between primitive solar system materials and X-winds. Chondrules and calcium-aluminum-rich inclusions (CAIs) experienced short melting events uncharacteristic of the asteroid belt where meteorites originate. The inner edge of the solar nebula has the shortest orbital timescale available to the system, a few days. Protosolar flares introduce another timescale, tens of minutes to hours. CAIs may form when solids are lifted from shaded portions of the disk close to the Sun and are exposed to its intense light for a day or so before they are flung by the X-wind to much larger distances. Chondrules were melted, perhaps many times, by flares at larger distances from the Sun before being launched and annealed, but not remelted, in the X-wind. Aerodynamic sorting explains the narrow range of sizes with which CAIs and chondrules are found in chondritic meteorites. Flare-generated cosmic-rays may induce spallation reactions that produce some of the short-lived radioactivities associated with primitive solar system rocks. This revised version was published online in June 2006 with corrections to the Cover Date.     

太阳能无人机能源系统的关键技术与发展趋势

作为探索临近空间领域的新兴飞行器，太阳能无人机（SUAV）在性能、技术及任务航时均呈现出不同于传统飞行器的新特点。其中，太阳能无人机能源系统的比能量、比功率是影响飞机整体性能的核心因素。因此，本文首先对太阳能无人机的太阳电池、储能电池的发展现状进行了阐述，然后针对能量获取多元化、能源系统管理高效化、能源载荷一体化方向对太阳能无人机能源系统的未来发展趋势进行了展望。     

TCM-2热电偶自动检定系统

ＴＣＭ－２热电偶自动检定系统，采用人机对话的形式，改变了以往检定热电偶的手工操作过程。以微机为中心，配以高精度的控浊信和多通道检测系统，自动控温，进行数据采样与处理，并直接打印检定结果。设有计算和检索的辅助功能。满足国家检定规程的要求。     

Graviresponses of osteocytes under altered gravity

Single cell was capable of sensing and responding to alterations of gravity. Osteocytes, as the most abundant cells of the bone tissue playing an important role in the bone mechanotransduction, are very sensitive to mechanical stimuli. However, the effect of altered gravity on osteocytes so far is less known according to the public papers. Further study on this issue will help to verify and develop the theory of how cells perceive and respond to gravity. It also brings new ideas to the study of space bone loss. In our study, Osteocyte-like MLO-Y4 cells were exposed to 30 parabolic flights three times on ZERO-G airbus A300 to investigate the comprehensive effect on osteocytes stimulated by hyper- and hypo-gravity forces. It showed that the cell morphology, as well as cell area and height, was not changed significantly by hyper-gravity and hypo-gravity. However, the cytoskeleton was reorganized. In flight cells, F-actin polymerization was enhanced at the cell periphery and microtubule organizing center disappeared, but no apoptotic feathers were detected. The results of western blot showed that connexin 43 (Cx43) expression was down-regulated, indicating an decrease of gap-junction. In conclusion, hyper- and hypo-gravity stimulation altered the cytoskeleton architecture and suppressed gap-junction of osteocyte-like MLO-Y4 cells.     

Numerical investigation on adiabatic film cooling effectiveness and heat transfer coefficient for effusion cooling over a transverse corrugated surface

Three-dimensional numerical computations are conducted to investigate the effects of the blowing ratio and corrugation geometry on the adiabatic film cooling effectiveness as well as the heat transfer coefficient over a transverse corrugated surface. It is noticeable that the adiabatic wall temperature on the wavy valley of the transverse corrugated surface is relatively lower than that on the wavy peak. Surface corrugation has a relatively obvious influence on the laterally-averaged adiabatic film cooling effectiveness in the region where the effusion film layer is developed, but has little influence in the front region. Compared to a flat surface, the transverse corrugated sur-face produces a smaller adiabatic film cooling effectiveness and a higher heat transfer coefficient ratio. The effusion cooling difference between the flat and corrugated surfaces behaves more obvi-ously under a small aspect ratio of the wavy corrugation.