全文获取类型
收费全文 | 647篇 |
免费 | 95篇 |
国内免费 | 39篇 |
出版年
2024年 | 2篇 |
2023年 | 4篇 |
2022年 | 3篇 |
2021年 | 12篇 |
2020年 | 26篇 |
2019年 | 24篇 |
2018年 | 7篇 |
2017年 | 23篇 |
2016年 | 26篇 |
2015年 | 18篇 |
2014年 | 56篇 |
2013年 | 132篇 |
2012年 | 37篇 |
2011年 | 27篇 |
2010年 | 28篇 |
2009年 | 39篇 |
2008年 | 35篇 |
2007年 | 27篇 |
2006年 | 28篇 |
2005年 | 32篇 |
2004年 | 36篇 |
2003年 | 21篇 |
2002年 | 13篇 |
2001年 | 15篇 |
2000年 | 16篇 |
1999年 | 14篇 |
1998年 | 13篇 |
1997年 | 11篇 |
1996年 | 10篇 |
1995年 | 5篇 |
1994年 | 8篇 |
1993年 | 13篇 |
1992年 | 6篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1989年 | 2篇 |
1975年 | 1篇 |
排序方式: 共有781条查询结果,搜索用时 15 毫秒
731.
Accelerated life testing (ALT) is commonly used to obtain reliability information about a product in a timely manner. Several stress loading designs have been proposed and recent research interests have emerged concerning the development of equivalent ALT plans. Step‐stress ALT (SSALT) is one of the most commonly used stress loadings because it usually shortens the test duration and reduces the number of required test units. This article considers two fundamental questions when designing a SSALT and provides formal proofs in answer to each. Namely: (1) can a simple SSALT be designed so that it is equivalent to other stress loading designs? (2) when optimizing a multilevel SSALT, does it degenerate to a simple SSALT plan? The answers to both queries, under certain reasonable model assumptions, are shown to be a qualified YES. In addition, we provide an argument to support the rationale of a common practice in designing a SSALT, that is, setting the higher stress level as high as possible in a SSALT plan. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2013 相似文献
732.
733.
734.
Transnational terrorism data are difficult to forecast because they contain an unknown number of structural breaks of unknown functional form. The rise of religious fundamentalism, the demise of the Soviet Union, and the rise of al Qaeda have changed the nature of transnational terrorism. ‘Old School’ forecasting methods simply smooth or difference the data. ‘New School’ methods use estimated break dates to control for regime shifts when forecasting. We compare the various forecasting methods using a Monte Carlo study with data containing different types of breaks. The study's results are used to forecast various types of transnational terrorist incidents. 相似文献
735.
Siegfried S. Hecker 《The Nonproliferation Review》2013,20(2):445-455
North Korea has the bomb but not much of a nuclear arsenal. For fifty years, it pursued the plutonium path to the bomb in parallel with its pursuit of nuclear electricity. My visits to North Korea's Yongbyon nuclear complex provided a window to its plutonium capabilities. After having made six visits to North Korea, Pyongyang surprised me during my seventh visit last November by showing me a small, modern uranium enrichment plant, which I was told was needed for its new indigenous light water reactor program. However, the same capabilities can be used to produce highly enriched uranium bomb fuel. Following a pattern of having made poor risk-management decisions during much of the past twenty years of diplomacy dealing with the North Korean nuclear threat, Washington remains in a standoff with Pyongyang. 相似文献
736.
Michael Krepon 《The Nonproliferation Review》2013,20(2):457-463
Forecasting Nuclear Proliferation in the 21st Century: The Role of Theory (vol. 1, 312 pages, $24.95) and A Comparative Perspective (vol. 2, 488 pages, $24.95), edited by William C. Potter with Gaukhar Mukhatzhanova. Stanford University Press, 2010. 相似文献
737.
Clifton W. Sherrill 《The Nonproliferation Review》2013,20(1):31-49
Understanding why the Iranian regime wants to possess nuclear weapons is essential to formulating the best policy to prevent (or perhaps to simply manage) the emergence of a nuclear-armed Iran. Three general theories—realism, liberalism, and constructivism—provide a framework for looking at Iran's nuclear motivations. However, contrary to many analyses, the regime's desire to possess nuclear arms stems not from neorealist defensive concerns, but rather from offensive goals driven by domestic politics. The use of extremist Islamism by the Iranian regime to justify its autocratic rule is the primary motivating factor. Accordingly, the outlook for diplomatically addressing the Iranian regime's nuclear aspirations appears dim. 相似文献
738.
Stephen I. Schwartz 《The Nonproliferation Review》2013,20(2):205-208
This article offers a survey of risks that might arise for strategic stability (defined as a situation with a low probability of major-power war) with the reduction of US and Russian nuclear arsenals to “low numbers” (defined as 1,000 or fewer nuclear weapons on each side). These risks might include US anti-cities targeting strategies that are harmful to the credibility of extended deterrence; renewed European anxiety about a US-Russian condominium; greater vulnerability to Russian noncompliance with agreed obligations; incentives to adopt destabilizing “launch-on-warning” strategies; a potential stimulus to nuclear proliferation; perceptions of a US disengagement from extended deterrence; increased likelihood of non-nuclear arms competitions and conflicts; and controversial pressures on the UK and French nuclear forces. Observers in North Atlantic Treaty Organization (NATO) states who consider such risks significant have cited four possible measures that might help to contain them: sustained basing of US nonstrategic nuclear weapons in Europe; maintaining a balanced US strategic nuclear force posture; high-readiness means to reconstitute US nuclear forces; and enhanced US and allied non-nuclear military capabilities. These concrete measures might complement the consultations with the NATO allies that the United States would in all likelihood seek with respect to such important adjustments in its deterrence and defense posture. 相似文献
739.
Elena K. Sokova 《The Nonproliferation Review》2013,20(2):209-212
Russia holds the largest stocks of civilian highly enriched uranium (HEU) of any country, operating more than fifty research reactors, pulsed reactors, and critical assemblies using HEU, as well as nine HEU-fueled icebreakers. Russia's participation in international efforts to phase out civilian HEU is crucial if international HEU minimization efforts are to succeed. Individual Russian institutes and organizations participate in international programs to replace HEU with low-enriched uranium in Soviet-supplied research reactors, develop alternative fuels, and repatriate fresh and spent HEU fuel from third countries. However, an overarching national policy on HEU phase-out has yet to be adopted. There are many obstacles to obtaining such a commitment from Moscow. At the same time, the ongoing reform of the Russian nuclear industry and plans for expansion of domestic nuclear power generation and for increased nuclear exports create opportunities for securing such a commitment. 相似文献
740.
Torrey Froscher 《The Nonproliferation Review》2013,20(2):419-424
Preventing Catastrophe: The Use and Misuse of Intelligence in Efforts to Halt the Proliferation of Weapons of Mass Destruction, by Thomas Graham Jr. and Keith A. Hansen. Stanford University Press, 2009. 300 pages, $35. 相似文献