内外干扰因素对液体火箭发动机的影响分析

在已有的液体火箭发动机稳态工况的非线性数学模型基础上,计算分析了单干扰因素对液体火箭发动机参数的影响,用非线性方法和小偏差方法对比分析了两个干扰因素分别和共同对发动机参数的影响。所得结论可用于泵压式燃气发生器循环的液体火箭发动机试验结果分析、可靠性及故障分析,也揭示了此类发动机参数随各种干扰因素的变化规律     

造纸企业芦苇堆场火灾事故诱因及预防措施

针对近几年造纸企业原料（芦苇）堆场火灾事故日益攀升的问题,从芦苇堆垛的湿度、通风、布置、温度监测手段以及外来火源控制等方面阐述了其与芦苇堆场火灾事故间的关联,并在此基础上探讨了有效预防芦苇堆场火灾事故的措施,期望为造纸企业与消防部门就芦苇堆场火灾事故的防范与控制提供参考。     

相似系统间调整因子的量化方法

探讨一种便于操作、系统而量化的方法 ,以预计新研系统的可靠性参数。在相似设备法的基础上 ,提出了利用可量化的调整因子对相似系统的可靠性参数进行转换的方法 ,有效地提高了相似设备法的可操作性和分析精度 ,对研究相似设备法在工程技术领域的应用也具有一定的参考价值     

一种由分抗干扰效果推出合成抗干扰效果的方法

提出了一种在外场雷达对抗试验中,由多部具有分抗干扰措施的雷达的抗干扰效果推出某种具有综合性抗干扰措施的雷达的合成抗干扰效果的方法,以在不具备该种雷达的情况下,用多部具有分抗干扰措施的雷达来代替它作为被干扰对象,在外场进行干扰机对其干扰的干扰效果试验检验。     

基于影响因素分析的装甲车辆驾驶员作业可靠性评价模型

从影响因素分析人手,在对装甲车辆人-机一环境系统物理模型综合分析的基础上,运用灰色关联度法建立了基于驾驶员作业可靠性影响因素分析的定性评价模型,并结合某装甲部队的驾驶训练考核进行了应用。结果表明：考核成绩与模型计算结果有着比较吻合的变化趋势,验证了模型的有效性。所述研究方法根据不同装备、不同岗位特点,可对评价指标体系调整后进行移植和拓展使用。     

基于ANP的装备保障转型影响因素分析

针对装备保障转型影响因素众多、转型重要程度难以确定等问题,分析了保障转型外部和内部影响因素,建立了保障转型影响因素ANP模型,利用ANP方法对装备保障转型影响因素进行了权重确定,为确定装备保障转型影响因素重要性程度提供了一种定量化分析方法,明确了装备保障转型应优先重点解决的关键问题．     

The Gravity of Arms

The aim of this paper is to investigate the determinants of international arms transfers in a gravity model framework. By distinguishing between the decision to export arms (extensive margin) and the value of the arms exported (intensive margin), while also considering its interdependence, is what differentiates this paper from previous research. A theoretically justified gravity model of trade augmented with political and security motives is estimated using a two-stage panel data approach for 104 exporting countries over the period from 1950 to 2007. In addition to the usual gravity variables related to the economic mass of the trading countries and the trade cost factors, the model is extended with political and security factors. The level of democracy in both trading partners, political differences between trading partners and voting similarity with the United States in the UN General Assembly of the countries engaged in trade are the main political factors, whereas the existence of conflicts, military pacts, and embargoes are taken as security motives. The key result indicates that both political and security motives are an important determinant of an arms trade, but their effects on the extensive margin of exports (the decision to order a transfer) differs from their effect on the intensive margin (average value of exports). Moreover, the relative importance of the factors under study has changed since 1989. In the post-cold war period, countries that are less democratic are more likely to export arms, military pacts are less relevant and embargoes play a role.     

空降作战的制约因素及前瞻

空降力量是联合作战力量的重要组成部分,空降作战是实施高技术条件下作战的重要手段,因此也是各国争相研究的课题,而空降作战指挥是制约空降作战效能发挥的主要因素。本文从空降作战指挥的特点出发,剖析了空降作战指挥的影响因素,通过对现代战争的形势分析对空降作战指挥的发展趋势做出了合理的预判。      

Clinical Characterization of Insomnia among Veterans with PTSD: Identifying Risk Factors for Diagnosis and Treatment with Sedative-Hypnotics

Abstract

Insomnia is prevalent among Veterans with post-traumatic stress disorder (PTSD), it exacerbates PTSD symptoms, and it contributes to impaired functioning and quality of life. To improve treatment outcomes, it is important to identify risk factors for insomnia and sedative-hypnotic use. Classification and regression trees and logistic regression models were used to identify variables associated with insomnia or sedative-hypnotic use. Key findings include low insomnia diagnosis rates (3.5–5.6%) and high rates of sedative-hypnotics (44.2–49.0%). Younger Veterans and those without a breathing-related sleep disorder (BRSD) were more likely to receive an insomnia diagnosis. Veterans with greater service connection and those with an alcohol/substance use disorder were more likely to be prescribed sedative-hypnotics. Interaction terms may have identified potential groups at risk of being under-diagnosed with insomnia (i.e. non-black Veterans with psychiatric co-morbidity, black Veterans without psychiatric co-morbidity) as well as groups at risk for sedative-hypnotic use (i.e. younger Veterans without BRSD). In sum, Veterans with PTSD have high rates of sedative-hypnotic use despite minimal evidence they are effective. This is counter to recommendations indicating behavioral interventions are the first-line treatment. Policy changes are needed to reduce use of sedative-hypnotics and increase access to behavioral insomnia interventions.     

差压式管道内检测机器人驱动力与速度分析

差压式管道内检测机器人是利用管道中流动介质压力差驱动的检测装置,机器人受力情况及周围流场分布对其运动状态有着重要的影响。通过对检测机器人受力分析和数值模拟,讨论了影响给定机器人驱动力的主要因素,得到了以水为流动介质在水平管道情况下,水流速度与机器人稳态速度的近似关系式,为以后进一步研究机器人定位提供帮助。