灰色层次理论在防空导弹武器系统效能评估中的应用

依据防空导弹武器系统效能的技术指标,给出层次结构模型,利用灰色层次决策和层次分析法,对防空导弹武器效能的综合评估提出了一种新方法.介绍了该方法的基本原理和解决问题的一般步骤.通过具体实例表明,采用该方法是可行的.     

无管网七氟丙烷灭火系统在小面积精密仪器场所的运用

小面积精密仪器场所由于其精密性和重要性,适于设置气体灭火系统。通过分析比较各种气体灭火剂、有管网和无管网气体自动灭火系统的优缺点及其性价比,得出无管网柜式七氟丙烷灭火系统是小面积精密仪器场所最合适的灭火系统。     

不确定环境下装备采购项目组织结构评估研究

首先分析了装备采购项目组织结构柔性的概念、环境不确定性的主客观因素及组织结构柔性与环境不确定性匹配的涵义;其次提出了装备采购项目组织结构柔性与环境不确定性的评价指标体系和测度方法,并在此基础上设计了组织结构柔性与环境不确定性匹配度的计算方法及判断准则;最后给出了算例。     

Transverse relaxation characteristic and stress relaxation model considering molecular chains of HTPB coating based on pre-strained thermal aging

In order to accurately describe the transverse relaxation characteristic and stress relaxation modulus of HTPB coating during pre-strain thermal aging process, a one month thermal aging test was carried out at 70 C with pre-strain of 0％, 3％, 6％ and 9％, respectively. The low-field 1H NMR and stress relaxation modulus tests were carried out for HTPB coating at different aging stages. The stress relaxation model considering the molecular chains was proposed according to the changes of crosslinking chain and dangling chain of HTPB coating during pre-strain aging. The results showed that with the increase of aging time, the decay rate of transverse relaxation curve became faster, the transverse relaxation time decreased, the value of combined parameter qMrl increased, the proportion of crosslinking chain decreased, while the proportion of dangling chain increased. Moreover, the stress relaxation modulus increased, the crosslinking network structure of HTPB coating became denser and the degree of cross-linking increased. At the initial aging stage, the pre-strain will destroy the crosslinking network structure of HTPB coating to a certain extent. With the increase of aging time, the effect of pre-strain will gradually weaken and the influence of aging on materials will gradually increase. The correlations between the stress relaxation model considering the molecular chains and the test results were more than 0.9950, which can accurately describe the stress relaxation modulus of HTPB coating during the pre-strain thermal aging process.     

A new experimental way for the monitoring of the real/equivalent in-service-time of double base rocket propellant by coupling VST and PCA

The assessment of the real in-service-time(RIST)and the equivalent in-service-time(EIST)of double base rocket propellants(DBRPs)is of utmost importance for the safe storage and use of weapon systems as well as the efficiency of the accelerated aging plans.In this work,four DBRPs with similar chemical composition and different natural aging have been artificially aged at T = 338.65 K for 4 months with sampling every 30 days.The unaged and artificially aged samples have been investigated by vacuum stability test(VST)at five isothermal temperatures(T = 333.15 K,343.15 K,353.15 K,363.15 K,and 373.15 K).The volume of the evolved gases in VST was found to decrease with natural/artificial aging.Furthermore,the VST data were treated and subjected to principal component analysis(PCA).The results showed excellent discrimination of the DBRP samples according to their stability thermal properties.Most of the variance was described by the first principal component(PC1)whose scores were linearly correlated with the natural aging durations when PCA is applied on VST data obtained at T = 363.15 K.In light of the obtained results,a new experimental way for the estimation of the real/equivalent IST was proposed,which takes into account the impact of the natural aging of the sample.The approach predicts successfully the RIST of two similar DBRPs with a relative deviation of less than 2％.At the specific heating temperature T = 338.65 K,the developed model provides more conceivable EIST values,with asymptotic behavior against artificial aging duration evolution,thus overcoming some shortcomings of the common generalized van't Hoff formula(GvH).     

枪械产品可靠性建模方法研究

选择适当的建模方法, 并在分析枪械产品可靠性试验特点的基础上提出了相应的假设, 讨论了确定具体模型类型的方法及不同类型数据的参数估计和检验手段。借鉴电子产品可靠性建模方法提出了针对枪械产品可靠性模型的建立步骤, 并结合某型自动步枪寿命试验数据给出计算实例。     

On the median residual lifetime and its aging properties: A characterization theorem and applications

This paper is devoted to study several aspects of the median residual life function (MERLF). In reliability studies, it is well known that, although the MERLF have several advantages over the mean residual life function (MRLF), the MRLF has the good property of uniquely determine a life distribution whereas either the median residual life function (MERLF) or an α‐percentile residual life do not have such good property. We shall give a characterization result where knowledge of both the MERLF and the survival function on an interval does uniquely determine the distribution. Moreover, in order to apply this characterization in practical situations, we propose a method to estimate the necessary information of the survival function. Relationships between analytical properties of the survival function and its associated MERLF are also obtained. Bryson and Siddiqui [J Am Statist Assoc 64 (1969), 1472–1483] proved relationships among seven criteria for aging, out of which two contained the MRLF (decreasing MRLF and net decreasing MRLF). In this paper, we prove that the same pattern of relationships holds if the MRLF is replaced by the MERLF. We also examine the aging criteria corresponding to an increasing MERLF and show that there is no relation between the behavior (increasing or decreasing) of the MERLF and of the MRLF. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005     

边防专业英语教学中存在的问题及对策

边防专业英语自身的特点和目前专业英语教学中面临的实际问题值得关注,改革边防专业英语教学,重视专业特色语言的教学,应采用任务式和讨论式教学来平衡学生的输入与输出,采用合作学习方式,注重学生的个性发展,培养复合型人才。     

对消防监督检查员专业资格标准的思考

随着国家法制化进程的不断深入,对从事消防监督检查的技术人员提出了越来越高的素质要求。为此,《消防监督检查员专业资格标准》征求意见稿应运而生。但“标准”的要求与消防部队的现实状况之间存在差距,解决好“标准”中的岗位等级与现行职称的衔接问题、“标准”规定的执业范围与基层人少事多的问题、“标准”规定的监督检查员申报岗位资格学历条件与现实状况之间的问题,有利于“标准”的执行。     

舰艇自防御的威胁排序方法研究

威胁评估与排序是舰艇自防御系统必须具备的重要功能。在多指标决策理论的基础上,结合灰色系统理论和逼近理想解方法,提出了灰色逼近理想解的威胁排序算法。首先通过建立舰艇自防御的空中威胁排序指标体系,得到各个指标的隶属度函数,再通过主客观结合的有序二元比较法得到威胁评估指标的权重,最后通过逼近理想解的灰色关联度方法对空中目标进行威胁评估与排序,并研究了分辨系数对威胁排序的影响。通过舰艇自防御防空作战实例证明了算法的有效性和工程实用性。