溶液盐度对微生物固化珊瑚砂的影响

设置不同盐度的溶液环境,通过测试固化后的珊瑚砂柱无侧限抗压强度,以及扫描固化后的珊瑚砂颗粒微观结构,综合分析了溶液盐度对微生物固化珊瑚砂的影响。结果表明:珊瑚砂柱上部固化效果好于下部,固化后渗透性降低了约1个数量级,无侧限抗压强度均大于2 MPa,干密度相对初始干密度增加了约25%,最终无侧限抗压强度与干密度均随溶液盐度的增加而降低;在海水平均盐度(35‰)条件下,固化后的珊瑚砂柱无侧限抗压强度比淡水条件下降低了9%,干密度降低了4%,说明微生物固化技术在海水环境下运用是可行的;在不同盐度溶液下固化的珊瑚砂微观结构基本相同,颗粒间部分孔隙被碳酸钙填充,颗粒表面被大量形状不规则且带棱角的碳酸钙晶体包裹并相互粘结,形成了具有一定强度的整体。     

菌液脲酶活性对珊瑚砂微生物固化效果的影响

使用不同脲酶活性的菌液对珊瑚砂进行微生物固化试验,分析了固化后试样的渗透特性、干密度增量分数、无侧限抗压强度与应力-应变曲线特征,研究了菌液脲酶活性对珊瑚砂微生物固化效果的影响。试验结果表明:脲酶活性为0.5 mmol/(L·min)的菌液,固化反应速率较慢、产物偏少;脲酶活性为1.0~1.5 mmol/(L·min)的菌液,固化后的珊瑚砂试样渗透系数降低了约2个数量级,固化生成的碳酸钙量多且分布较均匀,具有较高的抗压强度;脲酶活性为2.0~2.5 mmol/(L·min)的菌液,固化反应速率过快,导致试样上部易被碳酸钙堵塞,固化不均匀,应力-应变曲线形态不规则。菌液脲酶活性会影响珊瑚砂微生物固化生成的碳酸钙总量,试验中脲酶活性为1.5 mmol/(L·min)的菌液固化效果最好,珊瑚砂试样强度高、均匀性好,应力-应变曲线较为平滑。     

延安新区高填方填筑黄土新型固化技术的影响因素

为研究改良黄土的新型固化技术及其影响因素,探究最优改良方案,通过正交试验分析了石灰掺量、硫酸钠掺量、交流电压和通电时间4个因素对改良黄土无侧限抗压强度的影响。结果表明:采用该新型固化技术改良黄土的方法行之有效,其无侧限抗压强度是同等压实度条件下现场回填压实黄土的3倍;各因素中硫酸钠掺量对改良黄土的强度影响最大,石灰掺量与通电时间次之,交流电压最小;最优改良方案为石灰掺量6%,硫酸钠掺量1%,交流电压80 V,通电时间50 s。     

添加剂CCCW作用下硫铝酸盐水泥固化土耐MgSO_4侵蚀性能及早期强度模型

针对目前水泥固化土耐硫酸镁侵蚀性能研究多基于硅酸盐水泥的现状,以硫铝酸盐水泥固化土为对象,采用外蚀(成型后浸泡)和内蚀(制作时内掺)2种方式制作了试件,探讨了硫铝酸盐水泥固化土在硫酸镁溶液侵蚀下的早期强度发展规律。通过等量替换的方式,研究了水泥基渗透结晶型防水材料(CCCW)占用土质量4%时,其对硫铝酸盐水泥固化土耐硫酸镁侵蚀性能的影响。基于水泥固化土稳固系数理论,分别提出了硫酸镁溶液在2种侵蚀方式下的硫铝酸盐水泥固化土早期强度JM和NM模型,并对模型进行了检验。结果表明:硫铝酸盐水泥固化土在硫酸镁溶液侵蚀下,早期强度呈先上升后下降的趋势,浸泡1~3 d时强度增大较快,在7 d时达到最大,14 d时有较大下降;侵蚀方式对硫铝酸盐水泥固化土早期强度有较大影响,内蚀方式下强度一直呈上升趋势,且较外蚀方式高1~2 MPa;等量替换方式下,CCCW会降低硫铝酸盐水泥固化土强度,但提高了其耐硫酸镁侵蚀性能,MgSO_4溶液质量浓度为1.5~18.0 g/L时,2种侵蚀方式下14 d强度一直呈上升趋势;基于水泥固化土稳固系数的硫铝酸盐水泥固化土早期强度JM和NM模型具有一定的可行性,14 d时间内强度预测值与实测值误差最高分别为7.31%和5.07%。     

CCCW对硫铝酸盐水泥固化土强度的影响

水泥土强度与自身密实度有很大关系,水泥水化生成的水化硅酸钙(C-S-H)凝胶能胶结土壤颗粒,但固化土中仍会存在大量孔隙;而水泥基渗透结晶型防水材料(CCCW)能促进水泥水化,生成不溶于水的结晶,填充固化土孔隙,提高固化土密实度。采用硫铝酸盐水泥(SAC)作为主固化材料,选取CCCW作为固化土外掺剂,研究了CCCW对SAC固化土力学性能的影响。结果表明:同质量分数条件下,CCCW固化土强度平均为SAC固化土的70%左右;低质量分数CCCW复合SAC会有效提高固化土强度,但随着质量分数的增加,SAC固化土7 d强度会逐渐降低;4%的CCCW复合到12%的SAC中,固化土强度要高于20%的SAC固化土强度。     

含模拟放射性核素~(133)Cs磷酸钾镁水泥固化体性能

按照GB 14569.1—2011要求对含Cs磷酸钾镁水泥固化体抗压强度、抗浸泡性、抗冻融性、抗冲击性和抗浸出性进行了研究,探讨固化体物相组成、微观形貌和固化机理。研究结果表明:含Cs磷酸钾镁水泥固化体具有较好的抗压强度、抗浸泡性、抗冻融性和抗冲击性;磷酸钾镁水泥对Cs的固化能力优越,42 d时Cs+累积浸出分数为38.761×10-3cm,远低于GB 14569.1—2011要求的0.26 cm;固化体物相分析和微观形貌分析表明,Cs Cl会参加水化反应生成Mg Cs PO4·6H2O晶体,固化体结构密实,机械固化效果好。     

无电焊接材料的燃烧速度和燃烧温度研究

采用高放热性的铝热剂（CuO＋Al）并加入适当的添加剂,制备了便携式的无电焊接笔材料,其燃烧速度可控,且具有高的燃烧温度。研究了反应剂颗粒大小、混料均匀性等对无电焊接笔材料的燃烧性能的影响。结果表明：反应剂粒径对无电焊接笔的燃烧速度具有显著影响,随着反应剂粒径的增大,燃烧速度明显减慢。反应剂粒径和混料时间是影响单位时间放热量和混料均匀度的主要因素,因而对无电焊接笔的燃烧温度具有明显影响。在一定的混料时间下,反应物粉末具有最佳的混料均匀性。反应物粒径小且混料均匀性好的无电焊接笔材料,其燃烧温度高。     

RFI用环氧树脂固化工艺研究

采用动态差示扫描量热(DSC)法,研究了E-44/E-21混合环氧树脂与GA-327(DDM改性芳胺)的固化过程,研究了升温速率对固化体系DSC曲线的影响,确定了该固化体系的反应动力学方程为dαdt=2.27×104exp(-(4764.65)/T)(1-α)0.861;采用最佳固化温度外推法得到E-44/E-21(6∶4)/GA-327体系的最佳固化制度为100℃/30min 120℃/30min。按该固化制度制备的浇铸体的固化度达95.7%,拉伸强度和弯曲强度分别为62.71MPa和97.92MPa。     

机场道面抢修用聚氨酯稳定集料的试验研究

以机场道面意外损毁的抢修为目的,进行了聚氨酯发泡快速稳定道面基层回填料的试验研究。试验结果表明,常温下用聚氨酯发泡稳定碎石集料,2 h无侧限抗压强度达到2.05 MPa,对道面结构的有限元分析表明,试验所用材料可满足道面基层的力学性能要求。     

冻融循环对气泡轻质土抗压强度的影响

对12组不同配比的试样进行不同冻融循环次数的单轴抗压强度试验,研究冻融循环对气泡轻质土抗压强度的影响。结果表明,冻融循环后,气泡轻质土具有较好的力学性能,水泥掺量和气泡掺量对其抗冻融特性的影响程度不同。水泥掺量可有效抵抗冻胀力,冻融循环次数对气泡轻质土具有较大的影响。气泡掺量适中,可显著提高气泡轻质土的抗冻融性能。水分是造成气泡轻质土冻融破坏的主要因素,在满足水泥水化所需的前提下,需要适当降低轻质土的含水率。最后,根据对气泡轻质土冻融破坏特点的分析,讨论气泡轻质土抗冻融破坏机理。     

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).     

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.     

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.     

The UK,interrogation and Iraq, 2003–2008

The UK’s interrogation operations during the conflict in Iraq (2003–2008) are often portrayed by the media as involving significant amounts of mistreatment. This article demonstrates that these practices are not necessarily representative of the UK’s interrogation operations across this conflict. In doing so it contributes to the limited literature on the practice of interrogation and on the UK’s combat operations in Iraq. The UK’s interrogation capability, and therefore its intelligence-gathering capability, is shown to have rested primarily with the military’s Joint Forward Interrogation Team (JFIT). The JFIT suffered from limitations to the number, training and experience of its interrogators and interpreters. It is argued that maintaining a permanent, higher level of preparedness for interrogation by the British armed forces is desirable.     

Remembering and forgetting Mirambo: Histories of war in modern Africa

ABSTRACT

While the study of organised violence is considered essential to understanding the history of the West, and accordingly imbued with various layers of meaning and remembrance, war is widely regarded as inimical to the modern nation in Africa and stable development more broadly. Using examples drawn from primarily from East Africa, this paper considers the ways in which warfare in the deeper (‘precolonial’) past has been framed and envisioned in recent decades, in particular by governments whose own roots lie in revolutionary armed struggle and who began life as guerrilla movements. While in some cases particular elements of the deeper past were indeed mobilised in pursuit of contemporary political goals, in many other scenarios histories of precolonial violence were beheld as problematic and unworthy of remembrance. This paper highlights the paradox and ambiguity which has attended the memory of key aspects of Africa’s deeper past.     

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.     

SIM—LISP:一个通信网络管理专家系统外壳的设计与实现

本文介绍了笔者为开发名为OONMES的网络管理专家系统所实现的一个简单专家系统工具SIM-LISP。SIM-LISP是一个用C/C++语言来实现的模拟LISP语言的可调用函数集,它短小精巧,速度快,可以完成针对网管专家系统的事实或规则知识的表示、匹配、合一和推理等基本操作,并有与知识对象的连接功能,是网管专家系统内核实现的支撑环境。     

Al Qaida on the US invasion of Afghanistan in their own words

This article consists of selected translations from captured interviews and dairies of Al Qaida members. The time period covered is from mid-2001 to early 2002 and concerns their operations in Afghanistan. The material clearly conveys a range of emotion, from confident to despondent, as well as efforts to contest the US actions. The first several pages give the reader context and some possible “lessons learned,” but the story(ies) are best told by the Al Qaida members themselves. All names are pseudonyms.     

基于GTST-DMLD-ESD的装备RMS建模仿真

装备的RMS是装备的重要设计参数,是影响战备完好和保障能力的关键因素.引入GTST-DMLD作为主要建模工具,建立起装备系统的RMS描述模型,以ESD为补充和扩展,对维修过程进行建模.并以GTST-DMLD-ESD模型作为装备RMS仿真的核心,对装备RMS仿真模型的总体框架进行了研究,并对各模块进行了较为详细的探讨.