利用数形结合方法求解几类代数问题

数学研究的对象是现实世界的数量关系(数)和空间形式(形)。“数”和“形”常按照一定的条件相互转化。数形结合思想是数学的重要的思想方法之一,并蕴于数学基础知识和基本技能之中,在数学解题中应用十分广泛。其实质是将抽象的数学语言与直观图形结合起来,发挥“数”与“形”两种信息的转化及其优势互补与整合,使逻辑思维与形象思维完美统一起来。对于培养学生的创新意识和创造思维具有积极的促进作用。     

再议数学解题中的化归方法

本文通过一些例题阐述了化归方法在解决数学问题时应遵循的五个原则,对师范院校的学生学习数学教法有一定的参考价值。     

TOPSIS法用于区域防空重点保卫目标排序计算

区域防空作战中优化选择重点保卫目标,集中部署优势防空兵力,才能确保重点目标不受或少受损失.分析了影响保卫目标重要性的主要因素,采取德尔菲法获得指标值,采用层次分析法得到指标权重,利用逼近理想解的排序法对保卫目标的重要性进行了定量分析.最后通过算例对算法的正确性和实用性进行了验证.     

爆炸复合接头剪切强度测试方法研究

参照正交各向异性层压复合板层间剪切强度的测试方法,提出了用于测试爆炸复合接头复合界面剪切强度的3种方法;并建立三维有限元模型,分别对3种测试方法进行模拟;最后分别对3种方法进行了测试试验.结果表明,3种试验方法均能有效测试爆炸复合接头的剪切强度,其中对称试件双切口拉伸法最适合实际应用.     

基于MSP430单片机的海浪水压场自动测量系统

提出了基于MSP430单片机的水压场自动测量系统的设计方案和实现方法并进行了实际测量.解决了自动测量系统中的低噪声、低功耗、高分辨率、大容量存储等关键技术.实验结果表明:该系统具有自动运行、电池供电、记录时间长等特点.适于高海况条件下的海浪水压场的测量.     

基于接触的捞雷具夹紧爪接触面形状优化

介绍了在捞雷具夹紧爪设计过程中引入的基于接触的有限元形状优化设计方法.传统的机械设计方法仅考虑了零件的几何尺寸,而对其形状的设计却考虑不够,导致设计结果不理想.文中将基于接触的有限元形状优化方法应用于传统的机械设计过程.对捞雷具夹紧爪建立基于有限元分析的优化设计模型,使夹紧爪既能满足打捞鱼雷的要求,又得到了优化的形状.结构的特性与受力状况均得到改善.     

NONPROLIFERATION POLICY CROSSROADS:

On October 1, 2008, Congress enacted a proposal that originated with President George W. Bush in 2005 to approve an unprecedented nuclear trade pact with India by removing a central pillar of US nonproliferation policy. Despite the numerous political challenges confronting the Bush administration, the initiative won strong bipartisan support, including votes from Democratic Senators Joseph Biden, Hillary Clinton, and Barack Obama. The four-year struggle to pass the controversial US-India nuclear trade agreement offers an exceptionally valuable case study. It demonstrates a classic tradeoff between the pursuit of broad multilateral goals such as nuclear nonproliferation and advancement of a specific bilateral relationship. It reveals enduring fault lines in executive branch relations with Congress. It vividly portrays challenges confronting proponents of a strong nonproliferation regime. This article is based on an analysis of the negotiating record and congressional deliberations, including interviews with key participants. It assesses the lessons learned and focuses on three principal questions: how did the agreement seek to advance US national security interests?; what were the essential elements of the prolonged state-of-the-art lobbying campaign to win approval from skeptics in Congress?; and what are the agreement's actual benefits—and costs—to future US nonproliferation efforts?     

Better is the Neighbor?

Abstract

This study applies the Sequential Panel Selection Method (SPSM), to investigate the convergence properties of the military expenditure of the North Atlantic Treaty Organization (NATO) during the period of 1990–2015. Compared to the traditional methods, SPSM considers fundamentally general spatial homogeneous and heterogeneous relationships with countries and examines the evolution of military expenditure. We find that four-fifths of NATO member countries have been convergent with the UK, but no country’s military expenditure is convergent with the US. This means that there is no significant linkage effect in the US for NATO military expenditure. While they are allies of the US, the majority of NATO member countries’ military expenditures are consistent with UK military expenditure. The main reasons are due to the geographical space layout and the international relationship convergence. The results indicate that more than four-fifths of NATO member countries have been coordinated with convergence theory and spillover effect.     

RELIABLE ENERGY SUPPLY AND NONPROLIFERATION

The phenomenon of global warming has led to a revival of the prospects for increased nuclear energy production worldwide, yet such increased production carries with it the increased risk of proliferation. To mitigate this risk, various multinational arrangements have been proposed to provide reliable supply of nuclear fuel while at the same time discouraging the construction of national plants for nuclear enrichment and reprocessing. This article provides a brief history of some of these proposals and concludes that the likelihood of success for such schemes as effective tools for nonproliferation is not high at this time. A proposal from the World Council on Renewable Energy to expand the understanding of supplier obligations under Article IV of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) to include the development of non-nuclear energy technologies for NPT parties in good standing is potentially a much better nonproliferation tool. Such an approach tracks the ideas contained in Title V of the Nuclear Non-Proliferation Act of 1978, which has recently received revived congressional interest.     

概念模型验证方法研究综述

概念模型验证是保证和提高仿真可信性的重要手段,是建模与仿真VV＆A中的重点和难点．首先将概念模型的验证方法划分为非形式化方法、静态方法、动态方法和形式化方法4类,并提出了一种基于本体推理的概念模型验证方法,然后对各种方法的基本思想、基本原理、基本过程、适用对象、优缺点进行全面的分析总结,明确了各种方法的优缺点和适用范围,为如何选用各种验证方法提供参考,也明确了下一步应重点研究的问题．