硝化羟烷基纤维素的制备及其力学性能

为克服硝化纤维素NC低温力学性能差的缺点,合成羟烷基纤维素HEC,然后在HNO3/CH2 Cl2混合体系中对HEC硝化,进而制备硝化羟烷基纤维素NHEC,分析不同配比的硝化体系对产品氮量的影响,接着对NHEC系列产品进行动态力学分析(DMA),研究醚化度及酯化度对玻璃化转变温度的影响,最后对NHEC样品进行了拉伸测试.研究表明,若要合成高氮量NHEC,HNO3的含量应适中,含量少硝化不够充分,含量多产生凝胶,阻滞硝化反应向HEC里层扩散,反而降低产品氮量；根据DMA结果,与NC相比较,NHEC具有较好的柔性,较低的玻璃化转变温度,且醚化度越高,玻璃化转变温度越低；拉伸测试说明,NHEC在低温下韧而强,改善了NC低温发脆的缺点.     

硝化剂五氧化二氮的合成与放大

对五氧化二氮(N2O5)的特性、合成及放大方法进行了概括和分析。同时，结合我国硝化工业的现状，介绍了较为可行的工业化合成路线，以及国外的一些N205生产动态和装置。     

硝酸酯增塑GAP粘合剂中CL-20/HMX共晶研究

采用悬浮液法以硝酸酯增塑端羟基叠氮聚醚(GAP)粘合剂为溶剂制备出了六硝基六氮杂异伍兹烷/奥克托今(CL-20/HMX)共晶,并对其进行了X射线衍射(XRD)、扫描电镜(SEM)、高效液相色谱(HPLC)测试。采用分子动力学方法构建了共晶晶面-硝酸酯模型,计算了硝酸酯在共晶主要晶面上的结合能、扩散系数。结果表明,产物与CL-20、HMX形貌不同,呈平面板状;HPLC测试结果表明,产物组分摩尔比为n_((CL-20))∶n_((HMX))=1.97∶1≈2∶1;XRD测试结果表明,产物是CL-20/HMX共晶且共晶晶面生长速率由小到大为(100)、(102)、(111)、(011);分子动力学模拟结果表明,硝酸酯溶剂-共晶晶面相互作用、溶剂扩散能力、界面状态的综合影响导致共晶晶面生长速率由小到大为(100)、(102)、(111)、(011)。     

4,6-二氨基间苯二酚盐酸盐合成研究

以三氯苯为原料,经硝化、水解和催化加氢三步反应,合成聚对苯撑苯并双噁唑(PBO)单体4,6-二氨基间苯二酚盐酸盐(DADHC)。研究了各中间体和单体合成中的影响因素,确定了各步反应的最佳工艺参数。对合成的各中间体和单体采用元素分析(EA)、傅立叶变换红外光谱(FT-IR)、氢核磁(1H NMR)、碳核磁(13C NMR)和高效液相色谱(HPLC)等方法进行了表征分析。结果表明,各中间体和单体均达到预定要求,纯度和收率较高。研制了一套单体防氧化分离Pd/C过滤装置,实现了Pd/C催化剂的回收再利用,解决了单体易氧化、Pd/C易失活难题,提高了生产效率,降低了生产成本。     

共形阵天线的相位合成

本文提出了一种新的平板阵和共形阵相位合成方法，该方法将激励的小的相位变化用线性方程近似，并采用最小平方法以迭代形式求解出激励相位的最终解，在同一阵列中仅利用阵元中的移相器，就能实现几种不同的波束，这在合成计算实例中进行了验证。     

固体推进剂用硝酸酯增塑剂的热安定机制研究进展

从硝酸酯在固体推进剂中的应用角度综述了硝酸酯的热分解机理和热安定机制的国内外研究进展。硝酸酯的热分解机理国内外均集中于非等温高温热分解行为和热分解动力学研究,对于使用温度下的硝酸酯的等温热分解机理、反应动力学和产物分布等方向研究相对较少;对于硝酸酯热安定机制的研究主要集中于苯胺型和苯脲型安定剂的初步安定效果探索,其后期安定机理、整体反应动力学过程以及安定剂和硝酸酯的定量配比关系的研究未见文献报道。截至目前,国内外已形成硝酸酯两步热分解机制——硝酸酯键的断裂与硝酸酯的自催化;初步探索出苯胺型和苯脲型安定剂前期安定作用过程,其中,苯胺型安定剂初步安定机制为安定剂氨基上的氢与二氧化氮结合生成HNO₂和N自由基,而后安定剂的N自由基结合NO,苯脲型安定剂安定机制为安定剂发生C-硝化和N-硝化吸收氮氧化物。但上述国内外研究成果尚不足以支撑硝酸酯热安定控制技术及固体推进剂高温可靠使用调控技术等研究。基于此,文章提出应将使用温度下的硝酸酯等温热分解热行为和热安定机制作为硝酸酯基础应用的重点研究方向的研究建议。     

钝感GAP微烟推进剂的能量性能计算

根据推进剂配方理论计算程序计算了含N-脒基脲二硝酰胺(FOX-12)、1,1-二氨基-2,2-二硝基乙烯(FOX-7)、3-硝基-1,2,4-三唑-5-酮(NTO)、三氨基三硝基苯(TATB)、3,4-二硝基呋咱基氧化呋咱(DNTF)、黑索今(RDX)、二硝酰胺铵(ADN)等高能钝感氧化剂及1,2,4-丁三醇三硝酸酯(BTTN)、二缩三乙二醇二硝酸酯(TEGDN)、三羟甲基乙烷三硝酸酯(TMETN)、N-丁基-2-硝酸酯乙基硝胺(Bu-NENA)等钝感增塑剂的几种单元推进剂和钝感微烟推进剂的能量性能。计算结果表明,所列的7种含能氧化剂中,由RDX和DNTF形成的单元推进剂的标准理论比冲分别为2 696.4 N.s/kg和2 610.2 N.s/kg,明显优于其他几种氧化剂。当采用DNTF部分取代GAP推进剂中的RDX或ADN后,推进剂的理论比冲、密度和特征速度相应提高。由于DNTF的感度低于RDX,因此DNTF引入推进剂中,对提高钝感GAP微烟推进剂的能量性能是有益的。     

二(2,2-二硝基丙基)硝胺的合成及热性能

以2,2-二硝基丙醇为原料,经缩合、硝化反应合成了二(2,2-二硝基丙基)硝胺(BDNPN)。用红外光谱、核磁共振、元素分析对中间体及目标化合物的结构进行了表征。优化了反应条件,硝化反应的最佳条件为nBDNPA:nHNO3=1∶30,反应温度为50℃,反应时间为1 h,收率92.1%。用DSC和TG-DTG考察了目标化合物的热性能。结果表明,BDNPN的热分解峰温为212.3℃,具有较好的热稳定性。     

霍尔推进器放电等离子体的数值模拟研究与发展

阐述了霍尔推进器的工作原理.介绍了等离子体模拟中的流体、粒子和混合三种模型,以及粒子模型中直接蒙特卡罗模拟(DSMC)、等离子体模拟(PIC)和PIC/DSMC混合模拟方法.给出了一维流体模型的假设条件和控制方程、DSMC的空间迭代和时间步进两种求解方法,以及PIC、PIC/DSMC混合法与典型二维混合模型的建立过程.讨论了三种模型的适用条件、局限性,以及发展趋势.     

地空导弹共架发射控制研究

现代空袭使用多种兵器进行全方位、饱和型攻击,为了与之进行有效对抗,不同防空导弹武器系统需要进行联合作战,其中将不同地空导弹武器系统采用共架发射,进行联合作战,除了能够拦截多目标,提升防空导弹武器抗饱和攻击性能外,还能提高武器系统的抗干扰能力和生存能力。本文通过对某型号防空导弹武器系统大小弹共架发射控制进行分析研究,提出了车载防空导弹(甲型导弹)与单兵肩扛防空导弹(乙型导弹)共架发射的思想,并对这两种导弹武器系统采用共架发射的关键技术途径进行了分析研究。     

Net electric power of concentrating solar mirror systems for application in space as a function of the distance to the sun

The use of solar radiation by means of concentrating solar mirror systems, such as parabolic and spheric configurations, mainly is an engineering problem. A decisive characteristic for the optimisation of a complete system with turboelectric power conversion is the thermal cycle applied. Besides the Carnot process, here taken up into the study as an ideal comparative process, suitable processes for the technological realisation are the Brayton process and the Rankine process. The Brayton process is a typical gas turbine process using only the gaseous phase. The Rankine process is a steam engine process using liquid and gaseous phase.The work in hand shows how such solar systems with turboelectric conversion are optimised with respect to their specific weight (kg/kW_e) and how the distance to the sun as well as technological data enter into the analysis.As expected, the Carnot cycle as an ideal comparative process for both types of systems shows the best results for the optimum specific mass of the system. Regarding the real processes, the Rankine cycle shows more favourable characteristics than the Brayton cycle. The difference of the specific masses of the real processes mainly results from the different thermal conditions at the radiator.The influence of the distance to the sun is as expected. The nearer to the sun the solar power system operates, the better is the optimum specific mass of the system. For distances to the sun between 0.3 and 1.0 AU the spheric system shows a better behaviour than the parabolic system. For distances to the sun greater than 2.0 AU the parabolic system shows better behaviour of the specific weight. In the region between 1 and 2 AU the better optimum specific mass of the system belongs to the technological data used in the analysis.     

影响模压成型碳/环氧复合材料制件性能的因素分析

文章简述了碳/环氧复合材料模压成型工艺特性,从模压成型模具基本要求、模压成型温度、压力和保温时间等工艺参数对制件性能的影响作了较为详细分析。文中还提出将复合材料基础理论分析应用于生产过程中,对有效控制制件工艺状态稳定及其性能具有一定的现实意义。     

光学遥感器整体优势突显中巴地球资源卫星的特色

中巴地球资源卫星高层技术决策立足两个发展中国家的具体国情，着眼于自身整体优势和国际应用，根据国际地球资源卫星发展趋势和客观规律，准确地把握了中巴地球资源卫星技术发展方向。科学合理地进行了多谱段及其不同分辨率的遥感器配置，使中巴地球资源卫星多种有效载荷技术性能和指标互补，综合技术指标先进，光学遥感器技术指标整体优势已经突显出中巴地球资源卫星的特色，瞻望发展前景遥感器技术水平将明显提高，卫星应用范围将日趋扩大。     

Potential of laser-induced ablation for future space applications

This paper surveys recent and current advancements of laser-induced ablation technology for space-based applications and discusses ways of bringing such applications to fruition. Laser ablation is achieved by illuminating a given material with a laser light source. The high surface power densities provided by the laser enable the illuminated material to sublimate and ablate. Possible applications include the deflection of Near Earth Objects – asteroids and comets – from an Earth-impacting event, the vaporisation of space structures and debris, the mineral and material extraction of asteroids and/or as an energy source for future propulsion systems. This paper will discuss each application and the technological advancements that are required to make laser-induced ablation a practical process for use within the space arena. Particular improvements include the efficiency of high power lasers, the collimation of the laser beam (including beam quality) and the power conversion process. These key technological improvements are seen as strategic and merit greater political and commercial support.     

But what is the true rationale for human spaceflight?

Human interest in spaceflight is ancient. It is therefore ironic that, at a time when humans finally have the capability to travel in space, the notion that we should do so is being questioned. The author analyses the reasons for this — the historical/political and technological contingency of the Space Age and the sudden falling away of the conditions which drove space activity — and in the process provides a critique of the forgoing article and the tendency to search for utilitarian justifications of human spaceflight. He argues rather that space programmes will thrive only when driven by non-material cultural and political forces. US-Russian cooperation, which has principally been undertaken for geopolitical reasons is a model for the future.     

Results of Measurements of Accelerations of Technological Devices onboard the FotonSpacecraft

This paper generalizes the results of measuring the residual accelerations arising when investigations in space materials science are carried out onboard the unmanned Fotonspacecraft. The levels of vibroaccelerations are analyzed in the frequency band of 1–500 Hz for the technological devices UZ01, UZ04, and POLIZON, developed by the Federal Unitary State Enterprise Barmin Design Bureau of General Machine Building (V.P. Barmin KBOM). The levels of accelerations are estimated in the frequency band of 0–1 Hz in the zone of technological operations of these facilities. The basic sources of vibroaccelerations acting upon the frames of devices are determined in the capsule zone, where technological processes of producing new materials take place. In the frequency band of 1–500 Hz the vibroaccelerations are shown to be generated by the operation of Fotonspacecraft units and a drive of capsule translation during the technological process. On the capsule frame they reach the values of (1–3) × 10^–3 g. The level of linear accelerations in the infralow-frequency band is determined by rotational motions of the Fotonspacecraft. It depends on the device location with respect to the spacecraft center of mass and does not exceed (1–7) × 10^–6 gin the steady-state regime in the zone of technological activity.     

Finger heat flux/temperature as an indicator of thermal imbalance with application for extravehicular activity

The designation of a simple, non-invasive, and highly precise method to monitor the thermal status of astronauts is important to enhance safety during extravehicular activities (EVA) and onboard emergencies. Finger temperature (Tfing), finger heat flux, and indices of core temperature (Tc) [rectal (Tre), ear canal (Tec)] were assessed in 3 studies involving different patterns of heat removal/insertion from/to the body by a multi-compartment liquid cooling/warming garment (LCWG). Under both uniform and nonuniform temperature conditions on the body surface, Tfing and finger heat flux were highly correlated with garment heat flux, and also highly correlated with each other. Tc responses did not adequately reflect changes in thermal balance during the ongoing process of heat insertion/removal from the body. Overall, Tfing/finger heat flux adequately reflected the initial destabilization of thermal balance, and therefore appears to have significant potential as a useful index for monitoring and maintaining thermal balance and comfort in extreme conditions in space as well as on Earth.     

航天器总装过程风险分析和工艺安全性设计

文章分析了航天器总装过程中的危险因素以及各总装作业单元的危险程度及危害性,阐述了总装工艺安全性设计的方法和意义,建议构建安全控制要素基础数据库,进行工艺安全分析和安全技术评价,以期为航天器总装的安全性设计提供参考。     

Design problems of large space mirror radiotelescopes

Large space antennas can solve some actual problems of fundamental and applied investigations. Mirror antennas of large diameters (up to tens or hundreds of meters) are designed using an automatically deployed truss frame as a base onto which the radioreflecting surface is pulled (long-wave version) or precisely controllable panels are mounted (shortwave version). The reasons are discussed why antennas of millimeter range can be promptly developed. The factors are considered that influence on the resultant precision of the reflecting surface of the space antenna: technological errors in the process of frame manufacturing; technological errors during manufacturing of the reflecting surface; deformations due to thermal or force effects. To operate in the millimeter wavelength range, it is required to design antennas with automatic control of the reflecting surface. The analysis of the mathematical model of a modular mirror leads to the conclusion about the basic possibility of its adjustment.     

Effect of liquid bridge form on oscillatory thermocapillary convection under 1 g and μg conditions

This study analyses the effect of temperature difference between hot and cool disk (ΔT), and non-dimensional liquid bridge volume (V/V_o) on the transition process from steady thermocapillary convection to periodic or chaotic thermocapillary convection in a liquid bridge modeled after the floating zone method under normal gravity and microgravity conditions. From normal gravity and drop shaft experiments, the difference of the regime of the steady state and the oscillatory state was clarified on the ΔT−V/V_o plane under 1 g and μg conditions. A gap or stability region was observed in the specific V/V_o range under 1 g conditions. In the gap or stable region, after the gravity changed from 1 g to μg conditions, the temperature signals showed oscillation. From these results, the critical temperature difference under the μg conditions appeared to be smaller than that under the 1 g conditions. Temperature signals were defined as 6 different types of states. The various temperature oscillatory state regimes were obtained on a ΔT−V/V_o plane under 1 g and μg conditions. Under μg conditions, in these experimental conditions, all temperature oscillatory states exhibited only the Periodic state.