全文获取类型
收费全文 | 416篇 |
免费 | 10篇 |
出版年
2021年 | 4篇 |
2019年 | 13篇 |
2018年 | 13篇 |
2017年 | 7篇 |
2016年 | 5篇 |
2015年 | 7篇 |
2014年 | 9篇 |
2013年 | 76篇 |
2012年 | 3篇 |
2010年 | 5篇 |
2009年 | 7篇 |
2008年 | 6篇 |
2005年 | 3篇 |
2004年 | 7篇 |
2003年 | 9篇 |
2002年 | 6篇 |
2001年 | 6篇 |
2000年 | 8篇 |
1998年 | 6篇 |
1997年 | 7篇 |
1996年 | 10篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 8篇 |
1992年 | 7篇 |
1991年 | 10篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1988年 | 6篇 |
1986年 | 10篇 |
1985年 | 8篇 |
1984年 | 8篇 |
1983年 | 5篇 |
1982年 | 4篇 |
1981年 | 6篇 |
1980年 | 11篇 |
1979年 | 6篇 |
1978年 | 6篇 |
1977年 | 5篇 |
1976年 | 8篇 |
1975年 | 7篇 |
1974年 | 9篇 |
1973年 | 3篇 |
1972年 | 7篇 |
1971年 | 12篇 |
1970年 | 7篇 |
1969年 | 8篇 |
1968年 | 7篇 |
1967年 | 4篇 |
1966年 | 7篇 |
排序方式: 共有426条查询结果,搜索用时 31 毫秒
391.
Colin D. Robinson 《Defense & Security Analysis》2019,35(2):211-221
To engage properly with the Somali National Army, to understand it in the hope of improving stability and the lives of over 12 million Somalis, good basic information on its composition and characteristics is necessary. Authoritative accounts on the subject have been scarce for over 25 years. This account seeks to detail the army’s dispositions across southern Somalia, and, more importantly, the brigades’ clan compositions and linkages. Clan ties supersede loyalties to the central government. The army as it stands is a collection of former militias which suffer from ill-discipline and commit crime along with greater atrocities. Estimates of numbers are unreliable, but there might be 13,000 or more fighters in six brigades in the Mogadishu area and five beyond. 相似文献
392.
Dmitrii Usanov G.A. Guido Legemaate Peter M. van de Ven Rob D. van der Mei 《海军后勤学研究》2019,66(2):105-122
The effectiveness of a fire department is largely determined by its ability to respond to incidents in a timely manner. To do so, fire departments typically have fire stations spread evenly across the region, and dispatch the closest truck(s) whenever a new incident occurs. However, large gaps in coverage may arise in the case of a major incident that requires many nearby fire trucks over a long period of time, substantially increasing response times for emergencies that occur subsequently. We propose a heuristic for relocating idle trucks during a major incident in order to retain good coverage. This is done by solving a mathematical program that takes into account the location of the available fire trucks and the historic spatial distribution of incidents. This heuristic allows the user to balance the coverage and the number of truck movements. Using extensive simulation experiments we test the heuristic for the operations of the Fire Department of Amsterdam‐Amstelland, and compare it against three other benchmark strategies in a simulation fitted using 10 years of historical data. We demonstrate substantial improvement over the current relocation policy, and show that not relocating during major incidents may lead to a significant decrease in performance. 相似文献
393.
394.
In this article, we are concerned with scheduling stochastic jobs in a flowshop with m machines and zero intermediate storage. We assume that there are n - 2 identically distributed and 2 fast stochastic jobs. Roughly, the main result states that the makespan is stochastically minimized by placing one of the fast jobs first and the other last. 相似文献
395.
396.
397.
ABSTRACTNovichok agents are a class of nerve agents developed by the Soviet Union during the Cold War. In light of the use of a Novichok agent in Salisbury in March 2018, two sets of proposals to amend Schedule 1 of the 1993 Chemical Weapons Convention (CWC) have been put forth, one jointly by the United States, Canada, and the Netherlands, and the other by Russia. Both sets of proposals will be discussed and voted upon at the next Conference of States Parties of the Organisation for the Prohibition of Chemical Weapons (OPCW) in November 2019. If either set of proposals is approved, it will be the first time that the list of chemicals subject to verification under the CWC will have been modified. This viewpoint will discuss these proposals, and argue that, if adopted, the joint proposal and the portions of the Russian proposal upon which consensus can be reached would significantly strengthen the CWC by considerably expanding the coverage of its Schedule 1 and bringing Novichok agents firmly within the CWC’s verification system. We also argue that, since the OPCW Technical Secretariat did not deem the fifth group of chemicals proposed by Russia to meet the criteria for inclusion in Schedule 1, Russia should withdraw this part of its proposal from consideration. The proposals have also served an important purpose in clarifying the identity of the chemical agent used in the Salisbury incident, squarely placing it within one of the two families of Novichok agents described by the Russian chemical-weapons scientist and whistleblower Vil Mirzayanov. If either proposal is approved in November, it will be important to conduct a thorough assessment of key precursors for the synthesis of Novichok agents and assess the need to amend CWC schedules and national and multinational export-control lists accordingly. 相似文献
398.
399.
Paul B. Rich 《Small Wars & Insurgencies》2019,30(4-5):1070-1076
400.
MacGregor and Harris (J Quality Technol 25 (1993) 106–118) proposed the exponentially weighted mean squared deviation (EWMS) and the exponentially weighted moving variance (EWMV) charts as ways of monitoring process variability. These two charts are particularly useful for individual observations where no estimate of variability is available from replicates. However, the control charts derived by using the approximate distributions of the EWMS and EWMV statistics are difficult to interpret in terms of the average run length (ARL). Furthermore, both control charting schemes are biased procedures. In this article, we propose two new control charts by applying a normal approximation to the distributions of the logarithms of the weighted sum of chi squared random variables, which are respectively functions of the EWMS and EWMV statistics. These new control charts are easy to interpret in terms of the ARL. On the basis of the simulation studies, we demonstrate that the proposed charts are superior to the EWMS and EWMV charts and they both are nearly unbiased for the commonly used smoothing constants. We also compare the performance of the proposed charts with that of the change point (CP) CUSUM chart of Acosta‐Mejia (1995). The design of the proposed control charts is discussed. An example is also given to illustrate the applicability of the proposed control charts. © 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2009 相似文献