关于(S)_+型映射的一个区域不变定理及其应用

本文运用拓扑度方法,获得一个关于(S)_+型映射的区域不变定理。作为它的应用,本文得到了扩张映射的满值性,从而部分地回答了著名数学家L.Nirenberg提出的一个关于扩张映射满值性的公开问题。     

奇异积分方程在裂纹板条动态断裂分析中的应用(I)

利用积分变换方法,将含Ｇｒｉｆｉｔｈ裂纹的无限长板条问题转化为Ｌａｐｌａｃｅ变换域中一Ｃａｕｃｈｙ型奇异积分方程。通过求解奇异积分方程和对裂纹尖端场的渐近分析,获得了Ｌａｐｌａｃｅ变换域中的动态应力强度因子。     

可分椭圆型偏微分方程的 FACR(L)算法及其并行实现

文中就解Dirichlet 边界条件的Poisson 方程给出了FACR(L)算法及其并行实现过程,讨论了FACR(L)算法的计算复杂性,给出了针对向量机YH—1的算法的参数L 的优选公式,在YH—1机上得到了较为理想的,数值试验结果。     

Contents and Author Index,Volume 19, 2012

The U.S. Congress, charged with overseeing U.S. nuclear weapons policy and programs, usually addresses such policies and programs through the annual authorization and appropriations process, focusing mostly on questions of how many and what types of weapons the United States should deploy, with little attention paid to questions about nuclear weapons strategy, doctrine, and policy. The oversight process has brought about some significant changes in the plans for U.S. nuclear weapons, including the elimination of funding for the Robust Nuclear Earth Penetrator study and the shift of that funding into a study of the Reliable Replacement Warhead. But with the focus on authorizations and appropriations, along with the divided jurisdiction over nuclear weapons policy and programs in congressional committees, Congress has not, either recently or during the Cold War and post–Cold War eras, conducted a more comprehensive review of U.S. nuclear weapons strategy, policy, or force structure. Changes in committee jurisdictions could affect the oversight process, but as long as nuclear weapons policy and programs remain a relatively low priority for most members of Congress, and the country at large, it is unlikely that Congress will pursue such a comprehensive debate.     

INDIA AND THE NEW LOOK OF U.S. NONPROLIFERATION POLICY

U.S. nuclear export policy has undergone major transformations since 1945, and the most recent change, as expressed in the July 18, 2005, India-U.S. Joint Statement, represents an especially significant shift in policy. The document reverses more than a quarter century of U.S. declaratory policy, suggesting that the current U.S. administration regards nuclear proliferation to be both inevitable and not necessarily a bad thing. This article investigates this policy shift, looking at the history of U.S. nuclear export policy and the potential ramifications of the new policy on the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). The author also touches on the potential effects of the Joint Statement on Indian-Pakistani relations. Finally, it is suggested that it is not too late for India and the United States to change the new policy with more consideration for the NPT and the Nuclear Suppliers Group Initiative.     

ACHIEVING NUCLEAR BALANCE

One of the most important questions affecting U.S. national security is the future size of the U.S. nuclear stockpile. While there is clear consensus within the U.S. government on the need to reduce the size of the arsenal, there is none on the best path to achieve these cuts; on the type of deterrent necessary to deal with future threats; or on the size of the production complex needed to support that arsenal. Creating a strategic commission to review these questions, as contemplated in the Fiscal 2008 House Defense Authorization bill, is a necessary first step to establish a sensible nuclear policy. The Reliable Replacement Warhead, which has the potential to transform the complex while preserving the current moratorium on nuclear testing, is a program worth exploring further if it stays within congressionally mandated bounds. As Congress considers both programmatic and policy matters related to U.S. nuclear weapons, it is vital that we also renew and strengthen U.S. leadership on nuclear nonproliferation.     

美军新版《太空作战》联合条令的主要内容、变化及分析

2013年5月29日,美军参联会发布新版《太空作战》联合条令。文章对新版条令的主要内容进行了概括,对新、旧版本条令的差异进行了分析研究。     

Defence spending and economic growth in South Africa: A supply and demand model*

This paper provides a contribution to the growing corpus of knowledge and understanding of the interaction between economic growth and defence spending in South Africa by specifying a Keynesian simultaneous equation model and estimating the system for the period 1961 to 1997. The model contains a growth equation, a savings equation, a trade balance equation and a military burden equation and when estimated by single equation and systems estimation methods is relatively well specified. There is evidence of an overall negative effect of military spending on the economy over this period, though the significance of individual coefficients is low. There is certainly no evidence of any positive impact, suggesting that cuts in military spending do present an opportunity for improved macroeconomic performance.     

The industrial structure of National Defence and transaction costs

A recent paper in Defence Economics suggests that “a single variable, the public opinion balance, ... when accompanied by a control variable measuring the proportion of responses in the ‘residuum’ (no opinion or keep the status quo), permits an accurate prediction of subsequent changes in the rate of change of U.S. defense outlays from the mid‐1960s through the 1980s” (Higgs and Kilduff, 1993, p. 227). In contrast, this comment provides evidence that since 1986 the Higgs‐Kilduff model frequently mispredicts the direction of U.S. defense spending. In addition, the average prediction error, and its variance, since 1986 consistently exceeds the average prediction error, and its variance, for the years prior to 1986.     

基于传输方程空化模型的定常自然空化流场数值计算

采用基于传输方程的空化模型,应用自主开发的软件对水翼和水下回转体定常自然空化流场进行了数值计算。采用基于压力修正和多块结构化网格的有限体积方法数值求解Favre平均的NS方程,运用k-ε两方程加壁函数的湍流模式封闭雷诺应力。计算结果与已有实验结果符合较好。