1995年国防计量工作要点

适应社会主义市场经济和发展高技术武器装备需要，认真做好国防计量“八五”计划科研项目的收尾工作以及“九五”计划的编制和科研项目立项准备；继续建立和完善型号工程计量保证系统；改善和提高校准实验室的运行和管理工作。l根据国防科技发展战略、武器装备发展计划和国防计量“九五’”计划纲要，编制好国防计量“九五”计划，搞好项目的立项论证。各一级计量技术机构．要编制好本专业《计量标准树图》，提出重点科研项目建议。2搞好卜＼五”科研项目的收尾工作。认真清理结转到“九五”的项目，对技术方案、技术指标有较大变化的，列入…     

追求战略与细节之和谐

用20年的时间实现我国民航从大国向强国的历史性转变，是中国民航为更好地服务国家经济社会发展全局、加快民航事业发展而作出的重大战略决策，是在新的历史高点上的新起点。决策明确了建设民航强国的指导思想、基本原则、战略目标和战略方案，并对今后一个时期的发展，分别提出“六大”战略任务和“两步走”战略步骤。     

浅析通用航空对西部大开发的促进与发展

实施西部大开发，是党中央在世纪之交的关键时刻作出的重大战略决策。实施西部大开发战略，进一步加快中西部地区的脱贫发展，是我国社会主义现代化建设的重要组成部分，是尽快缩小东西部地区差距、最终达到共同富裕的必然要求，也是进行全国经济的结构战略性调整，促进国民经济持续、快速、健康发展的重大举措。对全面实现小平同志制订的“三步走”发展战略，到２１世纪中叶基本实现国家的现代化，实现中华民族的伟大复兴，具有极其重要的现实意义和深远的历史意义。西部大开发是全党全国人民一项重要而紧迫的共同任务，也是航空工业实现跨…     

民航实施“科教兴业”战略中几个关键问题的探析

1995年召开的第二次全国科技大会明确提出了“科教兴国”的宏伟战略，民航科技大会也不失时机地提出了“科教兴业”战略。“科教兴业”战略的提出，充分体现出民航敢于抓住发展机遇的气魄和胆识。为实施这一战略，全民航都在为促进科教事业的进步扎扎实实地工作。但是，民航实施“科教兴业”战略必须高屋建机，抓住关键。本文对此试作初浅探析。一、基本指针——牢固坚持“科学技术是第一生产力’侦方针不动把马克思主义历来非常重视科学技术的社会作用。按照马克思的看法，科学是一种在历史上起推动作用的、革命的力量。邓小平同志更是把科…     

一次“巧合”带来的启示

2013年11月5—6日，在中国民用航空局与国际民航组织（ICAO）共同举办的低成本航空运输研讨会上，夏兴华、周来振副局长均在讲话中指出，“发展低成本航空运输是民航大众化战略的需要，符合厉行勤俭节约、反对铺张浪费的精神”；8天后的2013年11月15日，《中共中央关于全面深化改革若干重大问题的决定》在关于经济体制改革的第三条中指出，“必须立足于我国长期处于社会主义初级阶段这个最大实际，……，推动生产关系同生产力、上层建筑同经济基础相适应”。     

和谐社会与和谐世界

构建和谐社会,是现实理性向理想理性发展的最佳途径。社会和谐是中国特色社会主义的本质属性,“以人为本”是构建和谐社会的价值目标,使社会主义真正实现了从理论走向现实,从世界回到中国。“和谐社会”与“和谐世界”理念相映成趣,是内政与外交的有机统一,走出了“本本社会主义”和“理想社会主义”的盲区,是全世界共同的政治社会文化财富。构建“和谐世界”这一理念的提出,向世界宣告了中国未来的发展走向及发展目标。和谐世界本质上是21世纪中国新的国际秩序观、世界观、国家安全观,是中国对国际社会的贡献。     

树立服务航司鲜明导向 推进民航业高质量发展

<正>2015年，习近平总书记对民航工作作出重要批示：“民航业是重要的战略产业，要始终坚持安全第一，严格行业管理，强化科技支撑，着力提升运输质量和国际竞争力，更好服务国家发展战略，更好满足广大人民群众需求。”民航系统是由航空公司、空管、机场等运行单位组成的行业“生态圈”，航空公司（以下简称“航司”）在其中处于重要的主体地位。因此，     

管窥俄罗斯未来轰炸机PAK DA

俄罗斯已经宣布开始研制新一代战略轰炸机“未来战略航空兵系统”（PAKDA），但公布的相关材料非常有限。本文对一些来自网络的俄文信息进行了综合分析，对PAKDA的发展过程及其性能进行了一定的推测。     

印度软件外包产业发展对中部崛起的启示

印度针对软件产业发展的国际趋势与本国的人才、成本优势，通过制定国家战略以及在人才、产业园区、产业国际化、行业组织、知识产权保护、风险投资与企业上市等方面的政策与措施，在软件外包产业方面获得了巨大的发展。印度软件外包产业的发展对于我国中部地区实现崛起在战略的选择、制定与实施方面具有启示意义，具体包括：聚焦战略是中部地区产业发展的可行选择，应根据内外部条件选择适合的产业集中发展；高度重视“趋同空间”在区域崛起中的作用，通过利益相关者达成共识的过程保证战略方向与政策的正确性和有效性；制定产业扶植政策应有系统性、针对性与突破性；应为战略产业构建一个具有异质性的区域支持空间；全力培植与凝聚促进产业爆发式增长的“关键大多数”人才。     

论党对非公有制经济认识的不断深化

社会主义国家如何正确认识和对待非公有制经济是一个重大的理论和实践问题。针对这一问题，文章对非公有制经济在中国的发展经历了从十一届三中全会前的“割资本主义尾巴”，到党的十六大提出的“毫不动摇”地鼓励和支持其发展的曲折过程进行了探讨。     

The effect of inlet conditions on the flow and heat transfer in multiple rotating cavity with axial throughflow

This paper discusses experimental results from two different build configurations of a heated multiple rotating cavity test rig.Measurements of heat transfer from the discs and tangential velocities are presented.The test rig is a 70% full scale version of a high pressure compressor stack of an axial gas turbine engine.Of particular interest are the internal cylindrical cavities formed by adjacent discs and the interaction of these with a central axial throughflow of cooling air.Tests were carried out for a range of non-dimensional parameters representative of high pressure compressor internal air system flows(Re up to 5×106 and Rez up to 2×105).Two different builds have been tested.The most significant difference between these two build configurations is the size of the annular gap between the(non-rotating) drive shaft and the bores of the discs.The heat transfer data were obtained from thermocouple measurements of surface temperature and a conduction solution method.The velocity measurements were made using a two component,LDA system.The heat transfer results from the discs show differences between the two builds.This is attributed to the wider annular gap allowing more of the throughflow to penetrate into the cavity.There are also significant differences between the radial distributions of tangential velocity in the two builds of the test rig.For the narrow annular gap,there is an increase of non-dimensional tangential velocity V/Ωr with radial location to solid body rotation V/Ωr=1.For the wider annular gap,the non-dimensional velocities show a decrease with radial location to solid body rotation.      

Research on Auto-detection for Remainder Particles of Aerospace Relay Based on Wavelet Analysis

Aerospace relay is one kind of electronic components which is used widely in national defense system and aerospace system. The existence of remainder particles induces the reliability declining, which has become a severe problem in the development of aerospace relay. Traditional particle impact noise detection (PIND) method for remainder detection is ineffective for small particles, due to its low precision and involvement of subjective factors. An auto-detection method for PIND output signals is proposed in this paper, which is based on direct wavelet de-noising (DWD), cross-correlation analysis (CCA) and homo-filtering (HF), the method enhances the affectiv-ity of PIND test about the small particles. In the end, some practical PIND output signals are analysed, and the validity of this new method is proved.     

Preparation of Highly Dispersed Antimony-doped Tin Oxide Nano-powder via Ion-exchange Hydrolysis of SnCl4 and SbCl3 and Azeotropic Drying

Antimony-doped tin hydroxide colloid precipitates have been synthesized by hydrolysis of SnCl4 and SbCl3 using: (1) an ion-exchange hydrolysis to remove chlorine ions, and (2) isoamyl acetate as an azeotropic solvent to obviate water. The obtained dried powder is of high dispersivity without any need for further grinding. The size and dispersivity of the final particles are investigated with the aid of TG-DTA, BET, XRD and TEM. After having calcined, the antimony-doped tin oxide nanopowder possesses a tetragonal rutile structure with high dispersivity, uniform particles and low hard agglomeration.     

Effects of Mo on the Microstructure and Hydrogen Sorption Properties of Ti-Mo Getters

The effects of Mo on the microstructure evolution, porosity and hydrogen sorption properties of Ti-Mo getters are investigated in this work. The results show that the addition of Mo prolongs the densification process of Ti-Mo getters and results in a significant amount of sintered pores. With the Mo content increasing, the porosity of getters firstly increases reaching the maximum value as it at- tains about 7.5wt.%, and then drops. At the room temperature, the hydrogen sorption property of getters increases progressively with the Mo content increasing, but the tendency is not very clear before its content lies below 2.5wt.%. When the Mo content achieves about 7.5wt.%, the hydrogen sorption property proves to be the best. The discussion is made about the above mentioned phenomena inclusive of hydrogen sorption properties of getters under different activation conditions (from 500-750 ℃).     

超声速燃烧数值模拟中的湍流与化学反应相互作用模型

高精度数值模拟有助于理解超声速湍流燃烧中湍流与化学反应的相互作用,可为发动机燃烧室等工程应用设计提供可靠的预测模型。除直接数值模拟外,目前在湍流燃烧应用中使用的大涡模拟和雷诺平均Navier-Stokes模拟均需要借助模型模化发生在湍流小尺度上的流动与化学反应过程对湍流大尺度运动的影响。现有的湍流与化学反应相互作用模型大致可分为:火焰面类模型和概率密度函数类模型,2类模型在不同的应用中各自具有优势和局限性。此外,现有模型大都基于低马赫数燃烧,而超声速燃烧中通常会伴随快速混合、局部熄火和再着火以及激波等复杂过程,这为发展其中的湍流与化学反应相互作用模型提出了更多的挑战。     

适于低轨卫星IP网络的单核共享树组播算法(英文)

为了解决低轨卫星IP网络中现有典型源组播算法的信道资源浪费问题,本文提出了一套单核共享树组播算法,即核心群合并共享树(CCST)和加权核心群合并共享树(w-CCST)算法。CCST 算法包括动态近似中心(DAC)选核方法和核心群合并组播路径构建方法。DAC方法专为周期、规律运动的低轨卫星网络提出,不需要复杂的星上计算。在核心群合并方法中,以核节点作为初始核心群,通过核心群和剩余组成员的最短路径方法逐步扩展直至整棵组播树构建完成,从而使得组播树的树代价最小,大大提高了网络的带宽利用率和组播传输效率。w-CCST 算法中所提出的加权因子可以调整树代价和端到端传播时延之间的折衷程度,因此,可以通过调整加权因子来适度增大树代价、降低端到端传播时延以支持某些端到端时延要求苛刻的实时组播业务。最后,与低轨卫星 IP 网络中典型算法进行了性能比较,仿真结果说明,CCST 算法的平均树代价比其它算法显著降低,w-CCST 算法的平均端到端传播时延小于 CCST 算法。     

Jet Vectoring Control Using a Novel Synthetic Jet Actuator

A primary air jet vectoring control system with a novel synthetic jet actuator (SJA) is presented and simulated numerically. The results show that, in comparison with an existing traditional synthetic jet actuator, which is able to perform the duty of either “push” or “pull”, one novel synthetic jet actuator can fulfill both “push” and “pull” functions to vector the primary jet by shifting a slide block inside it. Therefore, because the new actuator possesses greater efficiency, it has potentiality to replace the existing one in various appli- cations, such as thrust vectoring and the reduction of thermal signature. Moreover, as the novel actuator can fulfill those functions that the existing one can not, it may well be expected to popularize it into more flow control systems.     

Nonlinear Adaptive Slewing Motion Control of Spacecraft Truss Driven by Synchronous V-gimbaled CMG Precession

The slewing motion control of a truss arm driven by a V-gimbaled control-moment-gyro (CMG) is a nonlinear control problem. The V-gimbaled CMG consists of a pair of gyros that must precess synchronously. The moment of inertia of the system, the angular momentum of the gyros and the external disturbances are not exactly known. With the help of feedback linearization and recursive Lyapunov design method, an adaptive nonlinear controller is designed to deal with the unknown items. Performance of the proposed controller is verified by simulation.     

An SOR Implicit Time-accurate Scheme in Calculating Unsteady Flows

A new time-accurate marching scheme for unsteady flow calculations is proposed in the present work. This method is the combination of classical Successive Over-Relaxation (SOR) iteration method and Jacobian matrix diagonally dominant splitting method of LUSGS. One advantage of this algorithm is the second-order accuracy because of no factorization error. Another advantage is the low computational cost because the Jacobian matrices and fluxes are only calculated once in each physical time step. And, the SOR algorithm has better convergence property than Gauss-Seidel. To investigate its accuracy and convergency, several unsteady flow computa- tional tests are carried out by using the proposed SOR algorithm. Roe’s FDS scheme is used to discritize the inviscid flux terms. Un- steady computational results of SOR are compared with the experiment results and those of Gauss-Seidel. Results reveal that the numerical results agree well with the experimental data and the second-order accuracy can be obtained as the Gauss-Seidel for unsteady flow computations. The impact of SOR factor is investigated for unsteady computations by using different SOR factors in this algorithm to simulate each computational test. Different numbers of inner iterations are needed to converge to the same criterion for different SOR factors and optimal choice of SOR factor can improve the computational efficiency greatly.