固体推进剂贮存寿命非破坏性评估方法(Ⅲ)——预测残留寿命延寿法

从动力学理论分析入手,结合推进剂老化特征参数的研究结果,研究了用非破坏性手段预估固体推进剂残留寿命的方法。动力学理论分析表明,反应活化能是老化温度的函数,活化能对老化温度存在线性依赖关系,且活化能对老化温度的依赖关系和指前因子对老化温度的依赖关系是等效的。研究结果表明,影响推进剂寿命的应力问题也可以转化为动力学问题来处理,且应力对推进剂寿命的影响显著。利用新推导的4参数动力学公式,结合适宜的特征参数,建立了预估推进剂残留寿命的非破坏性方法,该方法可用于到期导弹的延寿。     

石英晶振老化的建模与模型求解

为预测石英晶振的频率老化，提出了一种非线性时变模型。在一阶马尔可夫假设下，利用多层前向神经网络进行迭代逼近求解。对四种晶体的全部或部分实验数据进行了学习和预测试验。结果表明该模型不仅能拟合函数，而且可在存在野值时，根据以往的数据预测目前的频率。与其他线性模型相比，该模型的预测能力更佳，适用于多种类型的晶振老化模式，预测误差小，有很好的抗噪声能力。     

一种对抗环境下反辐射导弹瞄准点估计方法

针对传统反辐射导弹（anti\|radiation missiles, ARM）无法有效对抗有源诱偏干扰与雷 达辐射信号控制的问题,提出了一种对抗环境下反辐射导弹瞄准点估计方法：通过构造空间 谱测角与单脉冲测角复合测角系统,测量信号波达角,使ARM具备诱偏条件下的弹目信息测 量能力;利用高精度的捷联惯导系统（strapdown inertial navigation system,SINS）实 时获取ARM自身位置信息,通过量测转换、异常值剔出、目标位置估计等数据处理过程获取 目标精确位置,修正瞄准点,剔除了量测粗大误差,抑制了量测随意误差。通过本文介绍的 反辐射导弹瞄准点估计方法,ARM可在对抗的环境下获取准确的瞄准点,使ARM有效对抗有源 诱偏干扰与雷达辐射信号控制成为可能。仿真实验验证了方法的可行性和其对抗能力。
     

长服役期橡胶密封性能分析与寿命评估

鉴于在橡胶密封性能分析过程中鲜有考虑长期老化效应影响,文章首先基于时温等效理论,构建考虑热氧老化效应的橡胶密封性能分析理论模型,并采用该模型研究不同压缩率和性能变化指标对橡胶接触性能的影响规律。然后,建立橡胶密封计算的平均接触压力与试验测试的橡胶密封泄漏率间的函数关系,并将采用这一关系预测的橡胶密封的泄漏率与试验测试结果进行对比。最后,拟合橡胶密封泄漏率与老化时间之间的函数关系,经外推,实现对O形橡胶密封寿命的精确预测。     

2195铝锂合金应力松弛时效成形工艺制度

以2195-T8态铝锂合金为研究对象,探究工艺参数对其应力松弛时效行为的影响规律。试样经过固溶、淬火,进行不同预变形、时效温度及时效时间条件下的应力松弛时效实验。通过室温拉伸,测得应力松弛时效后试样的力学性能。基于正交试验的极差分析和方差分析,探究了预变形、时效温度和时效时间3个工艺参数对应力松弛量、屈服强度和延伸率的影响权重占比;进一步研究发现预变形不仅可以提高2195铝锂合金时效后的强度,还降低了应力梯度对材料力学性能不均匀性的影响;查明了实现2195铝锂合金应力松弛时效形性协同制造的合理工艺制度:180℃+4%预变形+时效时间12～16 h。研究工作为大型铝锂合金构件应力松弛时效形性协同制造工艺窗口的确定提供了重要支撑。     

基于局域均值分解的冲击响应谱时域波形合成新方法

冲击响应谱时域波形合成技术是目前实验室环境下模拟实际复杂冲击环境的重要手段。文章在研究局域均值分解(LMD)方法和冲击响应谱时域波形合成原理的基础上,对实测冲击时域波形进行分解得到一组具有不同频率分布的PF信号分量,然后对不同频率分布的PF信号分量进行聚类分析并重新构造得到一组新的PF信号分量,使得PF信号分量的频率-幅值特性与设定的冲击响应谱试验条件一致。将重构后的PF信号分量组合即可得到合成后的冲击时域波形。数值仿真分析结果表明,基于LMD的冲击响应谱时域波形合成新方法生成的冲击时域波形能更好模拟真实冲击环境,冲击响应谱具有较好的控制精度。     

On the contribution of space medicine in the public health care

With the beginning of space era, a new branch of medicine has arisen and has been developing along with human exploration of outer space. And even though space medicine mainly faces the same problems as traditional medicine--cosmonauts health care and their high efficiency--this branch, has its own features, associated with the unusual factors of space flight, of which weightlessness is the major one. During the development of manned cosmonautics (duration of a human stay in space has reached already 438 days), methods of cosmonauts medical support and monitoring of their condition have been developed, knowledge of human possibilities and methods of process of organism adaptation to various and frequently severe conditions of external environment have increased. All this led to the fact that nowadays space medicine can become useful for improvement of human health care not only in space but also on the Earth. Moreover, the problem of implementation of cosmonautics achievements, and in particular of space medicine, in practice of public health care presents one of the most important issues concerning human health care. It is also connected with public opinion which is more and more concerned about the efficiency of significant expenses on space activities, especially lately. People often are set by the questions: what has space given, what fruits has space research provided to mankind, which results of this research can be used on the Earth already today for improvement of their life, for discussion of many difficult earthly problems? In terms of using cosmonautics possibilities, its achievements for health care and treatment, it is possible to define a few branches, in which purposeful studies are carried out.     

基于自提取脉冲样本图的雷达信号快速提取法

针对电子侦察中截获的敌方雷达信号,估计敌方雷达参数、实现快速的雷达信号提取,对电子对抗决策有重要意义。基于脉冲样本图的描述方式,提出一种新算法,实现对截获的敌方雷达信号的快速识别。算法利用同种雷达信号脉冲之间的匹配相关性,通过脉冲的整体平移,在实现对脉冲样本图的自提取的同时,把用此脉冲样本图描述的雷达辐射源信号筛选出来。仿真分析表明该方法可以获得较高的成功率。     

基于湿热老化试验的航天器用丁腈橡胶贮存寿命预测

采用湿热加速老化试验的方法对航天器用丁腈橡胶材料的老化性能进行研究。以拉伸强度作为性能评价指标,结合Arrhenius模型与Eyring模型,建立航天器用丁腈橡胶材料的湿热老化寿命预测模型,并利用该模型预测丁腈橡胶材料的贮存寿命。结果表明,在湿热老化试验过程中,温度和湿度对丁腈橡胶材料的力学性能产生了较大影响;温度升高和湿度增加有利于丁腈橡胶材料老化反应速率的提高;以拉伸强度作为考察指标推算出丁腈橡胶材料在温度20℃、相对湿度60%的环境条件下贮存寿命为5.71年。     

Intuitive ultrasonography for autonomous medical care in limited-resource environments

Management of health problems in limited resource environments, including spaceflight, faces challenges in both available equipment and personnel. The medical support for spaceflight outside Low Earth Orbit is still being defined; ultrasound (US) imaging is a candidate since trials on the International Space Station (ISS) prove that this highly informative modality performs very well in spaceflight. Considering existing estimates, authors find that US could be useful in most potential medical problems, as a powerful factor to mitigate risks and protect mission. Using outcome-oriented approach, an intuitive and adaptive US image catalog is being developed that can couple with just-in-time training methods already in use, to allow non-expert crew to autonomously acquire and interpret US data for research or diagnosis.The first objective of this work is to summarize the experience in providing imaging expertise from a central location in real time, enabling data collection by a minimally trained operator onsite. In previous investigations, just-in-time training was combined with real-time expert guidance to allow non-physician astronauts to perform over 80 h of complex US examinations on ISS, including abdominal, cardiovascular, ocular, musculoskeletal, dental/sinus, and thoracic exams. The analysis of these events shows that non-physician crew-members, after minimal training, can perform complex, quality US examinations. These training and guidance methods were also adapted for terrestrial use in professional sporting venues, the Olympic Games, and for austere locations including Mt. Everest.The second objective is to introduce a new imaging support system under development that is based on a digital catalog of existing sample images, complete with image recognition and acquisition logic and technique, and interactive multimedia reference tools, to guide and support autonomous acquisition, and possibly interpretation, of images without real-time link with a human expert. In other words, we are attempting to replace, to the extent possible, expert guidance by guidance from a digital information resource. This is a next logical phase of the authors’ sustained effort to make US imaging available to sites lacking proper expertise. This effort will benefit NASA as the agency plans to develop future human exploration programs requiring increased medical autonomy. The new system will be readily adaptable to terrestrial medicine including emergency, rural, and military applications.     

基于模糊观测器的不确定非线性系统故障检测方法

给出了一种不确定非线性系统的基于模糊观测器的故障诊断方法。用T-S模型描述不确定非线性系统,从而得到一种新的模糊观测器,并给出了其稳定性约束条件LMI。将模糊观测器和实际系统的输出之差作为残差可对不确定非线性系统进行故障检测。最后给出了一个控制系统感应电机的故障诊断应用实例。     

基于分离策略的航天器多故障模式诊断方法

针对定性模型诊断方法在处理多故障模式复杂系统时计算量大,不能满足航天器自主诊断实时性要求的问题,提出了新的诊断方法。为了减小冲突识别的实时计算规模,引入冲突识别的分离策略,提出了解析冗余计算方法。扩展了候选产生算法,先识别可能的异常部件,再通过冲突环境对异常部件的故障类型进行确定,在实现多故障模式系统故障诊断的同时,缩小了匹配空间。以某卫星一次电源系统为例,通过与现有算法进行对比,验证了本文的方法能够有效地减小诊断的规模,提高诊断效率,满足航天器自主诊断的需求。     

海洋环境中基于小波变换的弱信号检测新方法

海洋环境中弱信号的谱与海杂波的谱相混叠,目标和背景的位置差异很小,经典的频域或空域处理对海杂波中弱信号的检测难以奏效。鉴于小波变换在提取弱信号方面具有独到的优势,提出了一种海洋环境中基于小波变换的弱信号检测方法。利用雷达采集的真实海杂波数据,在不同信杂比的条件下,研究了该方法与经典频域法在信号检测中的差别。通过实验分析,与经典方法相比,当信杂比达到-14.7dB时,仍能很好地对信号进行检测。     

基于遗传算法的故障诊断规则提取方法的研究

针对粗糙集应用于故障诊断过程中存在的决策表属性连续值离散化和属性约简之间分离的问题,根据粗糙集的约简思想,本文研究了一种新的基于遗传算法的规则自动提取方法,可以在知识获取过程中同时实现属性连续值离散和属性约简。将该方法用于卫星电源系统故障诊断,可以从故障决策表中直接提取规则,得到超过90%的故障诊断准确率,进一步验证了这种方法的可行性和有效性。     

区域特色产业经济的管理制度——以近代安国药业为例

近代安国药业的繁荣与其管理制度有着密不可分的联系。近代时期，安国建立了独具特色的药业管理制度，构建了基本合理的药材生产、交易以及从业人员管理体系，从而为整个安国药业的发展起到了体制上的重要保障。     

固体发动机可靠性设计面临的问题及其解决方法

针对可靠性设计没有数据导致可靠度无法计算的困难,提出放弃可靠度而使用事件流分析来控制产品可靠性的方法,该方法将产品主事件分解为一系列的事件,任何一个事件都可以分为应力(L)、应构(G)、应变(B)和传递(D)4个要素,每个要素都可以提出一些可测量的工作控制指标,只要能够确保每个工作控制指标符合设计意图,就能控制产品不出现故障。根据这种观点,提出了发动机可靠性设计的事件流分析技术,先按照事件发生顺序一步步地分析产品工作中会发生的各种事件,每个事件都用LGBD的结构展开,然后分析监测每个要素需要的测量参数,以及控制每个要素需要的设计参数,从而确定完备的工作控制指标体系,并确定可靠性试验方案。该方法放弃了可靠性模型,代之以事件流模型,为可靠性设计提供一种全新方法。     

一种新的雷达辐射源识别算法

针对雷达信号环境,运用综合分析的方法,提出了一种新的基于模糊综合评判的雷达辐射源识别算法。该算法通过构造模糊评判矩阵并进行合成运算来计算表示辐射源相关程度的模糊集,然后按照最大隶属度原则进行判决,同时给出了相应的多义性处理方法。最后通过仿真将它与经典的统计模式识别方法进行了比较。仿真结果表明,所提出的识别方法性能明显优于统计模式识别方法,用于雷达辐射源识别是有效的。     

某固体推进剂湿热老化模型

通过对常用失效物理模型的分析和总结,结合量子力学理论关于电子产品老化反应速率与环境温、湿度的关系,以推进剂力学性能参数为研究对象,建立了固体推进剂贮存使用寿命的湿热老化模型,并通过试验数据拟合得到具体的经验公式。该模型可作为湿热环境下固体火箭推进剂贮存使用寿命预估的理论依据,也可作为固体火箭发动机剩余寿命计算的参考模型。     

Wayfinding Through Orientation

Dominant approaches in computer-assisted wayfinding support adhere to the deeply problematic principles of turn-by-turn navigation. In this article, we suggest a new approach called “Wayfinding Through Orientation,” which supports the acquisition of spatial knowledge and cognitive mapping for advancing the user’s spatial orientation. Being oriented on one’s way is a prerequisite to enabling people to verify instructions and to incorporate new spatial information into their existing knowledge structure. In three studies described in this article we first present empirical evidence that people can be supported in survey knowledge acquisition through suitable wayfinding instructions. Consequently, we explore orientation information in human wayfinding instructions. Finally, we outline how orientation information can be communicated within a prototypically implemented navigation assistance system.     

论高校医院与全科医学

摘 要 保证高校教职工、大学生的身心健康，是高校医院义不容辞的责任。为此，应探索一条更适合高校实际情况的医疗模式。本文就高校医院应如何为师生员工提供全方位的医疗保健服务进行了初步探讨。