全文获取类型
收费全文 | 492篇 |
免费 | 23篇 |
国内免费 | 1篇 |
出版年
2021年 | 6篇 |
2019年 | 11篇 |
2018年 | 9篇 |
2017年 | 13篇 |
2016年 | 10篇 |
2015年 | 9篇 |
2014年 | 10篇 |
2013年 | 125篇 |
2012年 | 7篇 |
2011年 | 9篇 |
2010年 | 8篇 |
2009年 | 7篇 |
2008年 | 7篇 |
2007年 | 6篇 |
2006年 | 11篇 |
2005年 | 9篇 |
2004年 | 6篇 |
2003年 | 5篇 |
2002年 | 6篇 |
2000年 | 5篇 |
1997年 | 7篇 |
1996年 | 10篇 |
1995年 | 6篇 |
1994年 | 8篇 |
1993年 | 12篇 |
1992年 | 12篇 |
1991年 | 9篇 |
1990年 | 4篇 |
1989年 | 10篇 |
1988年 | 9篇 |
1987年 | 8篇 |
1986年 | 7篇 |
1985年 | 10篇 |
1984年 | 5篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1981年 | 7篇 |
1980年 | 9篇 |
1979年 | 8篇 |
1978年 | 8篇 |
1976年 | 7篇 |
1975年 | 13篇 |
1974年 | 6篇 |
1973年 | 9篇 |
1972年 | 5篇 |
1971年 | 5篇 |
1970年 | 6篇 |
1969年 | 4篇 |
1968年 | 5篇 |
1967年 | 4篇 |
排序方式: 共有516条查询结果,搜索用时 15 毫秒
351.
In discussing China's January 2007 hit-to-kill intercept of the Chinese weather satellite FengYun-1C, most American analysts sought the “message” for the United States—either by asserting that China's test was a deliberate step toward a comprehensive counterspace capability to offset U.S. conventional military superiority or an attempt to force the United States to the negotiating table on “the prevention of an arms race in outer space.” Chinese officials, after a long silence, eventually claimed the test was an “experiment” that was “not targeted at any country.” We traveled to China several times in 2007 and had a series of conversations with Chinese individuals knowledgeable about the history of this particular antisatellite program and with access to information about the decision-making process prior to and after the final test. These discussions were off the record, not for attribution, given the sensitivity of the subject. They reflected the views of some of the key institutions involved in the test from the State, the Communist Party, the People's Liberation Army, and aerospace experts involved in debris calculations. The information conveyed to us suggests that American commentators tend to place much greater importance on the United States as a driver in China's decision to develop the technology and conduct the test than do the Chinese. 相似文献
352.
353.
354.
Tactical learning is critical to battlefield success, especially in a counterinsurgency. This article tests the existing model of military adaption against a ‘most-likely’ case: the British Army’s counterinsurgency in the Southern Cameroons (1960–61). Despite meeting all preconditions thought to enable adaptation – decentralization, leadership turnover, supportive leadership, poor organizational memory, feedback loops, and a clear threat – the British still failed to adapt. Archival evidence suggests politicians subverted bottom-up adaptation, because winning came at too high a price in terms of Britain’s broader strategic imperatives. Our finding identifies an important gap in the extant adaptation literature: it ignores politics. 相似文献
355.
This article is concerned with the determination of pricing strategies for a firm that in each period of a finite horizon receives replenishment quantities of a single product which it sells in two markets, for example, a long‐distance market and an on‐site market. The key difference between the two markets is that the long‐distance market provides for a one period delay in demand fulfillment. In contrast, on‐site orders must be filled immediately as the customer is at the physical on‐site location. We model the demands in consecutive periods as independent random variables and their distributions depend on the item's price in accordance with two general stochastic demand functions: additive or multiplicative. The firm uses a single pool of inventory to fulfill demands from both markets. We investigate properties of the structure of the dynamic pricing strategy that maximizes the total expected discounted profit over the finite time horizon, under fixed or controlled replenishment conditions. Further, we provide conditions under which one market may be the preferred outlet to sale over the other. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 531–549, 2015 相似文献
356.
357.
We consider a parallel‐machine scheduling problem with jobs that require setups. The duration of a setup does not depend only on the job just completed but on a number of preceding jobs. These setup times are referred to as history‐dependent. Such a scheduling problem is often encountered in the food processing industry as well as in other process industries. In our model, we consider two types of setup times—a regular setup time and a major setup time that becomes necessary after several “hard‐to‐clean” jobs have been processed on the same machine. We consider multiple objectives, including facility utilization, flexibility, number of major setups, and tardiness. We solve several special cases assuming predetermined job sequences and propose strongly polynomial time algorithms to determine the optimal timing of the major setups for given job sequences. We also extend our analysis to develop pseudopolynomial time algorithms for cases with additional objectives, including the total weighted completion time, the total weighted tardiness, and the weighted number of tardy jobs. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2012 相似文献
358.
We consider two opponents that compete in developing asymmetric technologies where each party's technology is aimed at damaging (or neutralizing) the other's technology. The situation we consider is different than the classical problem of commercial R&D races in two ways: First, while in commercial R&D races the competitors compete over the control of market share, in our case the competition is about the effectiveness of technologies with respect to certain capabilities. Second, in contrast with the “winner‐takes‐all” assumption that characterizes much of the literature on this field in the commercial world, we assume that the party that wins the race gains a temporary advantage that expires when the other party develops a superior technology. We formulate a variety of models that apply to a one‐sided situation, where one of the two parties has to determine how much to invest in developing a technology to counter another technology employed by the other party. The decision problems are expressed as (convex) nonlinear optimization problems. We present an application that provides some operational insights regarding optimal resource allocation. We also consider a two‐sided situation and develop a Nash equilibrium solution that sets investment values, so that both parties have no incentive to change their investments. © 2012 Wiley Periodicals, Inc. Naval Research Logistics 59: 128–145, 2012 相似文献
359.
G. Martynenko K. Avramov V. Martynenko M. Chernobryvko A. Tonkonozhenko V. Kozharin 《防务技术》2021,17(2):478-494
The new numerical approach for analysis of the warhead transportations is suggested.This approach allows to control the warhead operability before its experimental analysis.The approach is implemented by the adequate models for the software ANSYS.Analysis of the loads at land operations and trans-portations of the warhead by natural roads,water and aviation allows to obtain the maximal values of loads,which are used in numerical simulations of the warhead.These loads give an opportunity to analyze the operability and the fatigue strength of the cartridge warhead.The numerical simulations of the attachments of the warhead combat elements are performed on the basis of the suggested method.The data of the numerical simulations verifies the operability of the fastener system of the warhead combat elements. 相似文献
360.
Michael J. Armstrong 《海军后勤学研究》2007,54(1):66-77
This article considers two related questions of tactics in the context of the salvo model for naval missile combat. For a given set of targets, how many missiles should be fired to produce an effective attack? For a given available salvo size, how many enemy targets should be fired at? In the deterministic version of the model I derive a simple optimality relationship between the number of missiles to fire and the number of targets to engage. In the stochastic model I employ the expected loss inflicted and the probability of enemy elimination as the main performance measures and use these to derive salvo sizes that are in some sense “optimal.” I find that the offensive firepower needed for an effective attack depends not only on a target's total strength but also on the relative balance between its active defensive power and passive staying power. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007 相似文献