论民主及其内在关系

在人类政治文明的漫漫历史长河中，民主一直是人们苦苦追求的价值目标。但民主到底是什么，它的内在关系怎样？这恐怕是一个并没有完全解决好的理论问题。就这些方面作一些探讨，向读者展现现代人类历史上一个一以贯之的价值目标。     

弯曲致受抑全内反射式液位检测效应仿真实验分析

从传统的有损光纤结构的液位传感方法入手,深入研究塑料多模光纤传输过程中的包层模式下的弯曲损耗、受抑全内反射以及光能量耦合机理,在理论上揭示传感器效应的作用机制,从几何光学的理论出发,使用光线追迹方法,进一步模拟宏弯曲光纤内的光线传播路径,光纤受抑全内反射效应的能量变化机制,仿真结果与理论分析一致,搭建实验平台对前述理论分析和仿真模拟结果进行进一步的测试和验证。实验结果表明,该效应相对于传统有损光纤结构方法,可以进行高精度高灵敏度的稳定可靠液位传感测量。     

伞翼无人机线性自抗扰高度控制

针对伞翼无人机参数不确定性和复杂环境干扰敏感的问题,提出一种伞翼无人机线性自抗扰(Linear Active Disturbance Rejection Control,LADRC)高度控制方法。建立伞翼无人机8自由度飞行动力学模型,并引入风场和降雨模型以更加准确地模拟真实飞行环境。基于LADRC确定总体控制架构,设计线性扩张状态观测器对所有扰动进行估计,并引入误差反馈率在控制中实时补偿。使用该控制方法在多种扰动工况下进行伞翼无人机高度控制仿真实验。仿真结果表明,基于LADRC的高度控制方法能够有效克服内扰和外扰的影响,实现高精度高度控制;与传统PID控制效果相比,LADRC控制器具有更好的抗扰能力和鲁棒性。     

Reconsidering minimum deterrence in South Asia: Indian responses to Pakistan’s tactical nuclear weapons

India’s nuclear doctrine and posture has traditionally been shaped by minimum deterrence logic. This logic includes assumptions that possession of only a small retaliatory nuclear force generates sufficient deterrent effect against adversaries, and accordingly that development of limited nuclear warfighting concepts and platforms are unnecessary for national security. The recent emergence of Pakistan’s Nasr tactical nuclear missile platform has generated pressures on Indian minimum deterrence. This article analyzes Indian official and strategic elite responses to the Nasr challenge, including policy recommendations and attendant implications. It argues that India should continue to adhere to minimum deterrence, which serves as the most appropriate concept for Indian nuclear policy and best supports broader foreign and security policy objectives. However, the form through which Indian minimum deterrence is delivered must be rethought in light of this new stage of regional nuclear competition.     

Nuclear weapons,the United States and alliances in Europe and Asia: Toward an institutional perspective

America’s alliances in Europe and East Asia all involve some institutional cooperation on U.S. nuclear weapons policy, planning or employment—from consultative fora in Asia to joint policy and sharing of nuclear warheads in NATO. Such cooperation is often analyzed through the prism of “extended nuclear deterrence,” which focuses on the extension of U.S. security guarantees and their effect on potential adversaries. This article argues that this underplays the importance of institutional factors: Allies have historically addressed a range of objectives through such cooperation, which has helped to catalyze agreements about broader alliance strategy. The varied form such cooperation takes in different alliances also flows from the respective bargaining power of allies and the relative importance of consensus, rather than perceived threats. The article concludes that nuclear weapons cooperation will remain crucial in successful U.S. alliance management, as allies negotiate their relationship with each other in the face of geostrategic change.     

悬臂式围护桩受力性状与内力传递特征试验

为研究悬臂式围护桩结构的内力、弯矩、位移和嵌固段的变化规律及特点,结合西宁火车站综合改造工程,对该深基坑支护结构在不同开挖工况条件下悬臂桩的受力性状与内力传递特征进行现场动态测试试验。试验结果表明:悬臂桩的受力特征与理论值有所差异,在实际设计中可对其在配筋方式、混凝土强度设计、嵌固段长度等方面进行优化。试验结果可以有效优化桩身设计,为复杂基坑在开挖过程中的支护结构受力及变形提供参考性依据。     

Ungoverned space? Examining the FARC's interactions with local populations in Northern Ecuador

The Ecuadorian state has long been absent from the regions along its northern border with Colombia. I argue that this lack of state presence has allowed non-state armed groups and criminal organizations space to not only operate from these areas, but also, to challenge and change the relationship between local populations and the Ecuadorian state. After reviewing theoretical approaches to concepts of changing security paradigms and ungoverned space, the article details the conditions that have allowed armed groups, specifically the FARC, to take advantage of the lack of state presence along Ecuador's northern border.     

The African Peace and Security Architecture and its partners

This article presents survey data on the African Peace and Security Architecture (APSA). It focuses explicitly on two aspects: the internal constitution and achievements of the APSA; and coordination and cooperation with external actors, such as Regional Economic Communities, the United Nations and the European Union. The survey, conducted between October 2011 and December 2012, targeted 198 security experts in international organisations, think tanks, academia and non-governmental organisations. It reveals the APSA's current stage of development, achievements and challenges.     

SPARRING ON THE SUBCONTINENT

South Asian Security and International Nuclear Order: Creating a Robust Indo-Pakistani Nuclear Arms Control Regime, by Mario Esteban Carranza. Ashgate, 2009. 208 pages, $99.95.