飞刀展成蜗轮的数控方法

介绍了利用先进数控设备加工飞刀并展成蜗轮的方法 ,阐述了该方法的优点、飞刀的齿形计算和数控滚齿机展成蜗轮的操作流程。     

数控电解加工整体叶轮的关键技术

以平行直纹型面的数控展成电解加工为例，对数控电解加工整体叶轮的主要关键技术，包括成形规律、展成运动、数控编程、阴极设计制造、机库及多轴联动数控系统、典型叶轮加工工艺逐一进行了介绍。     

计算机辅助蓝图编程

本文提出了一种用于二坐标数控车床系统的蓝图编程功能的设计及实现方法，详细讨论了具有蓝图编程格式的数控程序向标准数据程序的转换。     

复杂型面数控加工工艺及编程技术研究

数控加工工艺与编程技术水平是影响产品加工质量和生产效率的重要因素之一。以航空燃油附件复杂型面的数控加工为典型实例,以实现高质量、高效率的加工效果为目标,重点介绍了数控加工工艺与编程思路及技巧,为数控加工技术的深度应用打下良好应用基础。     

飞刀展成蜗轮的数控方法

介绍了利用先进数控设备加工飞刀并展成蜗轮的方法,阐述了该方法的优点、飞刀的齿形计算和数控滚齿机展成蜗轮的操作流程。为利用高新设备改进旧的工艺方法提供了借鉴。     

基于Teamcenter的航天器产品数控编程管理研究与实现

在对航天器产品数控加工的特点及传统数控编程管理方式分析的基础上,基于Teamcenter 2007系统提出数控编程管理解决方案并在生产实际中进行了应用实践。     

复杂壳体零件数控加工技术

分析复杂壳体零件结构特点,加工难点,阐述了保证零件精度的数控加工技术。     

微机壳体类零件图形交互编程系统

图形交互式数拉编程是一种全新的编程方式，它是今后计算机编程技术发展的主流．本文介绍了在微机上实现壳体类零件图形交互式数控编程系统的总体考虑、技术特点和实施效果．     

用于数控编程的合屏编辑器

为了提高在线编程的质量和效率，本文介绍了一种新型的在ＣＮＣ上进行数控程序编辑的专用全屏编辑器的功能、特点及其设计和实现方法。     

列表点曲线数控加工编辑研究

本文提出了列表点曲线数控编辑的两种方法，给出了列表点曲线拟合的专用程序及数据处理和后置输出处理的专用程序模块，对在数控机床上加工列表点曲线以及使用行切法加工列表点曲面提供了一种精确快捷的手段。     

Linking Primordial to Solar and Galactic Composition

Evolution and composition of baryonic matter is influenced by the evolution of other forms of matter and energy in the universe. At the time of primordial nucleosynthesis the universal expansion and thus the decrease of the density and temperature of baryonic matter were controlled by leptons and photons. Non-baryonic dark matter initiated the formation of clusters and galaxies, and to this day, dark matter largely determines the dynamics and geometries of these baryonic structures and indirectly influences their chemical evolution. Chemical analyses and isotopic abundance measurements in the solar system established the composition in the protosolar cloud (PSC). The abundances of nuclear species in the PSC led to the discovery of the magic numbers and the nuclear shell model, and they allowed the identification of nucleosynthetic sites and processes. To this day, we know the abundances of the ∼300 stable and long-lived nuclides infinitely better in the PSC than in any other sample of matter in the universe. Thus, we know the exact composition of a Galactic sample of intermediate age, allowing us to check on theories of Galactic evolution before and after the formation of the solar system. This paper specifically discusses the nucleosynthesis in the early universe and the Galactic evolution during the last 5 Gyr.     

浅谈民用飞机适航性与计量测试之间的关系

通过研究分析适航文件规章、SAE标准和AS9100质量管理体系中与计量测试相关的内容和要求,结合当前国内行业主管部门对民用飞机计量测试专业的规划,从适航标准、适航管理和适航验证的角度,阐述了适航性与计量测试之间的内涵及关系,提出了开展民用飞机计量测试标准规范体系、法规体系和技术体系建设的必要性和重要意义。     

区域覆盖星座构型优化及协同控制策略研究

针对区域覆盖卫星星座的回归特性和构型维持需求,利用轨道半长轴和倾角与升交点赤经漂移和相位角漂移变化率之间的线性关系来优化星座构型参数,提高卫星星座构型的长期稳定性,同时通过协同控制轨道半长轴和倾角漂移量来实现区域覆盖星座构型维持。最后对区域覆盖天基雷达星座进行了构型优化设计和仿真,仿真结果表明了星座构型优化设计和维持策略的有效性。     

考虑工程约束的高可信度气动外形优化设计

实际气动设计中遇到的工程问题较为复杂,然而能够用于实际工程设计的高可信度气动外形优化设计工具较少.基于飞行器设计工程实际中的各种复杂气动约束和几何约束要求,集成高可信度非结构网格RANS方程求解器、弹簧比拟网格变形技术、FFD外形参数化、RBF代理模型、粒子群优化器,构建多设计点气动外形优化设计工具,并应用于先进低速层流翼型和高亚声速超临界机翼的气动外形优化设计中(包括单设计点和多设计点),进行考虑/不考虑气动约束和几何约束的气动外形优化设计分析.结果表明:多设计点气动外形优化设计工具有效,约束条件和智能优化器自动有效地引导了层流翼型和亚声速机翼外形的有利改变.     

The use of multiple receivers to measure the wave characteristics of very-low-frequency noise in space

Until now most very-low-frequency (VLF) radio noise experiments in the ionosphere, magnetosphere and solar wind have been able to provide only the amplitude and spectral characteristics of VLF phenomena. Experiments using multiple receivers to measure the amplitudes and relative phases of the magnetic and electric wave components, however, can give the wave characteristics in addition. Knowledge of both the spectral and the wave characteristics are desirable in making deductions about the noise source location and mechanism and about the properties of the propagation path. Expressions are derived for obtaining the electromagnetic wave characteristics — wave normal vector, Poynting vector and wave polarization — and the electrostatic wave characteristics — wave normal direction and field magnitude — from the amplitudes and relative phases of the wave components. The antenna systems capable of measuring the necessary wave components on payloads which are not spinning, spinning, or spinning and precessing are described. Consideration is given to the experimental technique of reducing payload interference, of transferring the required data to the ground and of obtaining the desired spatial, frequency, amplitude and phase resolution.The data obtained with such an experiment may represent the superposition of signals from multiple sources and multiple paths and from interference signals. Interpretation of these results is discussed and the use of the results of obtaining information on the source location and mechanism and on the propagation path properties is described. Recently several sounding rocket and satellite experiments capable of measuring some of the wave characteristics have been flown. The results concerning the wave normal directions for several different types of VLF noise phenomena are summarized.     

分供方测量的控制与管理

国际标准的推广实施，使企业计量工作的运作观念发生重大的变化，同时也给计量工作如何实效服务生产经营提出新的课题。本文结合质量体系认证、计量检测体系合格确认工作中的实践，分析、探讨了企业建立完善计量检测体系过程中，对分共方测量工作进行控制、管理的有关方法、难点。     

3D针刺C/SiC断裂韧性缺口敏感性及破坏研究

碳化硅陶瓷基复合材料是高超声速飞行器及高推重比发动机等发展所需的关键材料之一,对冲击断裂韧性、缺陷及裂纹的敏感性有较高要求。采用夏比冲击试验测定3D针刺C/SiC复合材料的断裂韧性,研究其处于U型、V型缺口分别在与针刺平行、垂直的不同分布方向时对冲击断裂韧性的影响,并通过扫描式电子显微镜及光学显微镜等手段详细分析断口形貌。结果表明：U型试样的断裂韧性较V型试样对缺口线与针刺相对位置更为敏感,且缺口线与针刺纤维束平行时断裂韧性最差;针刺纤维束与0°和90°无纬布铺层交叉部位相对薄弱,原材料抗剪能力削弱。     

Radio science investigations with Voyager

The planned radio science investigations during the Voyager missions to the outer planets involve: (1) the use of the radio links to and from the spacecraft for occultation measurements of planetary and satellite atmospheres and ionospheres, the rings of Saturn, the solar corona, and the general-relativistic time delay for radiowave propagation through the Sun's gravity field; (2) radio link measurements of true or apparent spacecraft motion caused by the gravity fields of the planets, the masses of their larger satellites, and characteristics of the interplanetary medium; and (3) related measurements which could provide results in other areas, including the possible detection of long-wavelength gravitational radiation propagating through the Solar System. The measurements will be used to study: atmospheric and ionospheric structure, constituents, and dynamics; the sizes, radial distribution, total mass, and other characteristics of the particles in the rings of Saturn; interior models for the major planets and the mean density and bulk composition of a number of their satellites; the plasma density and dynamics of the solar corona and interplanetary medium; and certain fundamental questions involving gravitation and relativity. The instrumentation for these experiments is the same ground-based and spacecraft radio systems as will be used for tracking and communicating with the Voyager spacecraft, although several important features of these systems have been provided primarily for the radio science investigations.     

高速磨削技术的发展趋势及其相关技术

回顾了国内外高速磨削技术的发展过程,从高速磨削机理,高速磨削速度及其高速磨削相关技术等方面介绍国外的发展水平和先进成果,预测了今后国外高速磨削研究的发展趋势,并从高速度磨床的一些技术特征和参数,以及人们对高速磨削的认识等方面分析和评价了我国在推广和应用高速磨削中尚存的差距,可为进一步深入研究提供参考.     

某大型飞机复合材料壁板工艺仿真及验证技术

热压罐固化成型是制造复合材料的常用方法,固化期间罐内温度分布变化以及模具与复合材料构件之间的热不匹配、柔性模具的低热导率等因素导致制件内部不可避免的产生温度梯度以及残余应力,从而影响材料的使用性能。大尺寸曲面帽型壁板采用复合材料热压罐工艺成型,根据热压罐的工作原理,针对复合材料构件热压罐成型过程中温度场分布和固化变形等问题,进行了仿真分析,通过对比制件温度场分布和固化变形仿真计算结果以及全尺寸零件的实际验证结果,验证了预测方法的正确性。分别利用成型工装和检测型架改进优化以及制造过程优化来控制构件固化变形,使其形状满足产品尺寸的精度要求,证明根据工艺仿真计算结果以及工艺过程改进,可以对大尺寸曲面帽型壁板在制造工艺过程中出现的变形回弹及残余应力水平进行预估和最大限度的减小,实现复合材料结构设计和制造的一体化,提高制件的成型质量。