聚氨酯/环氧树脂(PU/EP)AB-交联聚合物的研究

用二胺同时固化聚醚氨酯预聚物及环氧树脂,制得了PU/EP AB-交联聚合物(AB-CP)。以动态粘弹仪对其进行了表征,结果表明:形成AB-CP后,PU与EP相之间的相互作用大大加强(强于PU/EF IPN中PU与EP之间的作用),使PU链运动受到限制,其Tg移向高温区并形成了一个单一的Tg峰;研究了物料比、环氧值等对其动态力学谱(DMS)的影响。预期该化合物是一类有前途的增韧环氧树脂材料。     

聚醚氨酯/环氧树脂互穿聚合物网络的研究(Ⅱ)——动态力学性能

通过对 PU/EP IPN 进行动态力学测量发现:该 IPN 体系的 tgδ—T曲线中,PU 和 EP 对应的 Tg 峰均有不同程度的内移,在较宽的温域内(大于100O℃)tgδ值均很高(大于0.4)。结合 TEM 及 IR 表征结果,进一步表明:该体系中,PU 和 EP 网络间存在着强物理相互作用——永久缠结(即互穿)。     

聚醚氨酯/环氧树脂互穿聚合物网络的研究(Ⅰ):合成及表征

本文介绍了聚醚氨酯/环脂树脂(PU/EP)互穿聚合物网络(IPN)的一步本体合成法,用透射电镜(TEM)、红外光谱仪(FT—IR)对该体系进行了表征。结果表明:该体系中PU和EP网络间有互穿而无化学相互作用。该体系的微观形态结构依赖于下列因素:原料配比、PU网络的交联密度、PU软段长度、PU中链延伸剂结构及未固化EP的本体粘度等因素。     

聚醚氨酯/环氧树脂(PU/EP)互穿聚合网络(IPN)声阻尼性能的研究

将PU/EP IPN阻尼材料(卷材)贴附于钢制隔音罩内壁进行声阻尼性能测试,结果表明:该材料声阻尼性能优良,消声效果可达4.0dB(A)/mm。采用一定复合方式制成的复合隔音罩,可使本体噪音降低30～40dB(A)。     

聚氨酯／环氧树脂互穿网络聚合物

综述了聚氨酯／环氧树脂互穿网络聚合物(PU／EP IPN)的合成原理、动力学、相分离以及形态和性能,并介绍了PU／EP IPN的应用。     

基于Perl语言的含能材料耐热性能模拟

含能材料中聚合物的玻璃化转变温度(Tg)的高低可以作为其耐热性能的一个重要指标,为了方便快捷地使用Materials Studio分子模拟软件预测出含能材料中聚合物的Tg,在使用Materials Studio软件时引入Perl语言,开发了能自动进行升温的模拟程序,并在Perl语言环境下结合XML语言,设计与实现了一种基于XML的图形界面化的预测聚合物Tg的程序。以聚合物(PE)为算例预测了其Tg,实验结果表明该方法能自动、方便地对给定的分子模型进行阶段升温(降温)MD模拟,同时获得模型在不同温度下的密度,通过对模拟得到的密度-温度作图,可求得模型的Tg。其模拟结果与实验值相比,吻合得较好,表明该方法可以快速而有效地对聚合物的性能进行自动预测。     

典型外墙保温材料火灾特性的微燃烧量热仪实验研究

通过对我国建筑保温材料的调研与分析,选取了未经阻燃处理的XPS、EPS和PU建筑外墙保温材料,以及经过卤素阻燃处理的PU,采用微燃烧量热仪,对其典型火灾参数(燃烧组成值、热释放速率峰值、总热释放量和点燃温度)进行了实验分析.结果表明,同样未经阻燃处理的PU材料的燃烧组成值和热释放速率峰值不足PS材料相应火灾参数值的1/5,PU相对更显火灾安全性.此外,经过卤素阻燃的PU各释热相关参数值较小.     

EG/ATH/协效剂/聚氨酯阻燃复合材料的阻燃和力学性能

为了改善聚氨酯(PU)材料的阻燃性能,首先在PU中加入阻燃剂膨胀石墨(EG)、氢氧化铝(ATH)与阻燃协效剂磷酸三乙酯(TEP)、硼酸锌(ZB)和磷酸硼(BP);然后,通过氧指数仪、垂直燃烧测定装置和电子拉力试验机等表征了材料的性能;最后,用体式显微镜、扫描电子显微镜研究了阻燃材料的微观结构和燃烧后的碳层形貌,分析了材料力学性能下降的原因和燃烧机理。结果表明:随着PU中阻燃剂EG、ATH的添加量的增加,PU的阻燃性能逐渐提高,力学性能却逐渐减弱;TEP、ZB、BP对EG/ATH/PU体系的阻燃性能的协效作用明显,其中TEP协效作用最明显;综合考虑力学性能和阻燃性能,EG/ATH/协效剂/PU的最优配方为10gEG/50gATH/5gTEP/100gPU,其氧指数为34.3%,阻燃等级为V-0,拉伸强度为1.95MPa,断裂伸长率为140%。     

俄罗斯推出三种改进型R-27空空导弹

正俄罗斯最大空射武器制造商战术导弹公司(KTRV)表示开始对R-27空空导弹进行现代化升级,推出R-27R1/ER1、R-27P1/EP1和R-27T1/ET1等三种改进型号。所有改进型号专为米格、苏系列多用途战斗机定制,各型之间的区别在于导引头和推进系统有所不同。     

UHMWPE复合材料抗爆实验研究

运用定制的聚偏四氟乙烯(PVDF)压电传感器,直接测量爆炸载荷下UHMWPE层叠无纬布和PU基体的UHMWPE复合材料内部冲击波压力峰值,对其冲击波衰减特性进行了实验研究。实验结果表明:UHMWPE复合材料对爆炸冲击波有很好的衰减作用,含有PU基体的UHMWPE复合材料比UHMWPE层叠无纬布对爆炸冲击波有更好的衰减效果。UHMWPE复合材料具有轻质、吸收冲击波效率高等特性,在爆炸冲击波防护领域有很好的应用前景。     

An Unlikely Alliance: Portuguese and South African Airpower in Angola, 1968–1974

The war that Portugal was obliged to fight in Africa began in 1961 and immediately stretched the resources of its armed forces. Nowhere was this thinness more apparent than in policing the vast territory of Angola. The east and southeast of Angola were particularly vulnerable, as the area was a vast, sparsely populated region characterised by enormous featureless plains or chanas covered in tall grass and broken by an extensive river system and mountainous forests. The only military solution to policing these immense spaces was aviation and specifically the helicopter that could carry troops into battle, protect them with a gunship and bring them home when the operation was concluded. The immediate problem for the Portuguese Air Force (Força Aérea Portuguesa or FAP) in Angola and elsewhere was a scarcity of helicopters. The solution was an alliance with South Africa, which had a strong inventory of Alouette IIIs, to help in policing the east. This move was likewise in the interest of South Africa, as its threat came from Zambia through south-eastern Angola. This article examines the strategic and tactical development of this unusual, cross-cultural alliance and the symbiotic relationship that resulted in destruction of the enemies of both in Angola.     

Helping hands: civil–military cooperation and Italy's military operation abroad

In the Post-Bipolar Era the growing complexity of the military operations requires a new approach for the resolution of international crises. Since the end of the Cold War, peace support operations (PSO) have become the mainstay and principal occupation of most Western armies. At the same time, Italy has been one of the most important actors in such an area. The article focuses on the cooperation between military and civil components (a process called CIMIC) as a key variable in the Italian PSOs. We will analyse in detail the main lessons learned from past military interventions as well as the general context in which new tendencies are taking place. The maintaining of a minimum security frame becomes essential to fulfil activities ‘collateral’ to the mission: reconstructing services and infrastructure, food distribution, water and medication, law and order, de-mining, training of local forces, and supporting local institutions. These are the main tasks to obtain thrust and support from the population.     

Terrorism,insurgency, kidnapping,and security in Africa's energy sector

Energy continues to serve as the bedrock of modern economies and the main driver of modern society. For Africa, the production and supply of energy resources such as crude oil, natural gas, uranium, coal, biomass, biofuels and other renewables are an important source of employment, rents, taxes, royalties and profits. This sector brings in several tens of billions of dollars of revenue annually. The production and delivery of such resources, however, depend on critical infrastructures such as pipelines, refineries, processing plants, terminals, rigs, electrical energy pylons, substations, pump stations, vessels, and tankers. These infrastructures have been attacked by terrorists, insurgents, vandals and saboteurs, all of whom see them as targets against which to register their grievances and extract concessions from the state. This paper is a chronological account of some of the documented incidents of terrorism, insurgency, kidnapping, destruction, sabotage, and human casualties suffered in the oil and gas sectors in Africa between 1999 and 2012. It is based on data extracted from the databases of the RAND Database of World Terrorism Incidents and the University of Maryland's Global Terrorism Database (GTD).     

国内外结构钢焊条研究的现状与发展

本文主要介绍了国外焊条的现状和发展趋势,包括焊条的高韧性、高效率、低尘低毒和耐吸潮性能,为国内的焊条研究提供了参考依据。     

A Sign of Victory?: ‘Scottish Swords’ and Other Weapons in the Possession of the ‘Auld Innemie’

Many late medieval documents, notably inventories of arms and armour, of Englishmen contain references to ‘Scottish swords’ and other weapons. What did the compilers of these documents mean when they described a weapon as ‘Scottish’? How did such weapons come to be in the possession of these men? This article will attempt to explain this phenomenon drawing on primary documentary sources and surviving material culture from Glasgow Museums’ collections and others, as well as artworks from the period.     

Tacit support for terrorism: The rapprochement between the USSR and Palestinian guerrilla organizations following the 1967 war

This article demonstrates the inconsistent and wavering Soviet attitude towards national liberation movements in general and the Palestinian organizations in particular. Until the late 1960s, the Soviets viewed these organizations with suspicion, hesitating to engage in political dialogue with them. However, in the 1970s, political and military events in the region, as well as modifications in the Kremlin's Cold War strategies, led to a general shift towards the Middle East in Soviet foreign policy. Soviet leaders showed increased willingness to provide certain Palestinian organizations with arms with which to conduct terrorist activities against Israeli, pro-Israeli, Jewish and Western targets. The article explores the complex relations between Palestinian organizations and the USSR in the field of international terror. The study also exposes and analyzes the nature and content of Soviet–Palestinian arms dialogues and transactions. It provides clear evidence that Soviet policymakers and other luminaries were fully informed of, and sometimes directly involved in, these transactions and dialogues at the highest levels.     

A1 Qaeda and the radical Islamic challenge to western strategy

The September 11 global crisis prompted by the attacks on the World Trade Center and the Pentagon raises major questions concerning the nature and trajectory of terrorism in the post-Cold War global order. Hitherto, terrorism has been largely debated by analysts at the level of nation states. Terrorist and insurgent movements have also been largely anchored in nationalist and ethnic power bases even when they have sought to mobilise a transnational ideological appeal on religious or class grounds. There have been a few exceptions to this pattern such as the alliance between the German Baader-Meinhof group and the Japanese Red Army Faction, but even such international alliances as this did not, until at least the 1980s, presage anything like a global terrorist network necessitating a global strategic response. This study examines terrorism and global strategic responses.     

Helping hands: external support for the KNU insurgency in Burma

This article analyses to what extent the Burmese KNU insurgency made use of external support from states, refugees, and diasporas. Based on extensive fieldwork it is concluded that support from neighbouring states and refugees has for years kept the Karen rebellion alive. Western countries perceived forms of resistance to the illegitimate Burmese regime as just and have therefore played a crucial role in the continuation of conflict in Karen State. It is important that policymakers and donors as well as executing organizations continue to reflect critically on the way they exercise their work.     

Cyberpower in Strategic Affairs: Neither Unthinkable nor Blessed

Abstract

This article explores the effect of connectivity on strategic affairs. It argues that the effect on war's character is potentially, although not yet shown in practice, considerably large. Its effect upon the distribution of power among states in the international system is small, contrary to the claims of ‘cyberwar’ alarmists. All told, however, its effect upon strategic affairs is complex. On the one hand, it represents a significant advance in the ‘complexification’ of state strategies, understood in the sense of the production of intended effects. On the other hand, strategists today – still predominantly concerned with the conflicts and confrontations of states and organised military power – are generally missing the power which non-traditional strategic actors, better adapted to the network flows of the information age, are beginning to deploy. These new forms of organization and coercion will challenge the status quo.