全文获取类型
| 收费全文 | 973篇 |
| 免费 | 27篇 |
| 国内免费 | 9篇 |
专业分类
| 1009篇 |
出版年
| 2025年 | 6篇 |
| 2024年 | 6篇 |
| 2023年 | 18篇 |
| 2022年 | 10篇 |
| 2021年 | 20篇 |
| 2020年 | 16篇 |
| 2019年 | 23篇 |
| 2018年 | 14篇 |
| 2017年 | 33篇 |
| 2016年 | 29篇 |
| 2015年 | 36篇 |
| 2014年 | 64篇 |
| 2013年 | 132篇 |
| 2012年 | 54篇 |
| 2011年 | 51篇 |
| 2010年 | 45篇 |
| 2009年 | 52篇 |
| 2008年 | 42篇 |
| 2007年 | 37篇 |
| 2006年 | 41篇 |
| 2005年 | 46篇 |
| 2004年 | 32篇 |
| 2003年 | 21篇 |
| 2002年 | 29篇 |
| 2001年 | 23篇 |
| 2000年 | 14篇 |
| 1999年 | 24篇 |
| 1998年 | 9篇 |
| 1997年 | 8篇 |
| 1996年 | 18篇 |
| 1995年 | 7篇 |
| 1994年 | 13篇 |
| 1993年 | 9篇 |
| 1992年 | 12篇 |
| 1991年 | 5篇 |
| 1990年 | 8篇 |
| 1989年 | 2篇 |
排序方式： 共有1009条查询结果，搜索用时 0 毫秒
161.
Amanda Moodie 《The Nonproliferation Review》2013,20(1):71-82
ABSTRACTSince the 1990s, the group of stakeholders working to combat biological weapons (BW) proliferation has broadened to include new actors who have not traditionally focused on security issues, including organizations from the public health sector, researchers in the life sciences, and the biosafety community. This has had significant benefits for the Biological and Toxin Weapons Convention (BWC) and the arms control establishment more broadly. However, the BWC's agenda has become increasingly dominated by issues of international health and global health security. By focusing solely on response strategies, the United States and other interested parties risk losing sight of other important elements of a counter-BW strategy, including deterrence and prevention. Focusing on public health-related issues to the exclusion of more traditional security matters puts the nonproliferation regime at risk, because it limits the amount of time that stakeholders have available to grapple with the critical questions facing the BWC and the biological weapons nonproliferation establishment—questions that must be answered if the regime is to survive. 相似文献
162.
Joshua Masters 《The Nonproliferation Review》2013,20(3):347-361
As the potential for the involvement of corporations in the manufacture of nuclear weapons has increased, particularly through dual-use technology, global regulation has failed to keep pace. Where regulation of private corporations does exist, in the form of treaties, UN resolutions, or more informal arrangements, the obligations fall only on states. This state of affairs is a result of international law's traditional deference to state sovereignty; yet, it has led to significant shortcomings in the global regulatory regime, where states are unwilling or unable to meet their obligations. While radical departures from the traditional model of international law might remove the regulatory gaps caused by noncompliant states, such changes are unrealistic in the current political climate. More realistic changes must be focused on, offering greater recognition of the role of private corporations in nuclear proliferation and increasing state compliance with existing regulation. 相似文献
163.
涡轮盘是航空发动机主要部件之一,一旦发生破坏性故障将导致严重的后果。在充分考虑影响涡轮盘高低周复合疲劳寿命因素不确定性基础上,以MATLAB为平台,设计了涡轮盘高低周复合疲劳寿命可靠性优化设计的联合仿真平台。利用寿命函数和寿命可靠性分析极限状态函数中的共性需求,提出了在优化迭代的过程中自适应构建寿命函数Kriging模型和寿命可靠性极限状态面Kriging模型时共用训练样本点的策略。同时,提出了一种构建寿命函数Kriging模型的学习函数。使用所搭建的疲劳寿命可靠性优化设计平台,完成了某型涡轮盘盘心、榫槽以及涡轮盘系统高低周复合疲劳寿命的可靠性优化设计。结果表明,最优设计方案的局部最大应力显著降低,均值寿命大幅提高,并满足可靠性约束。 相似文献
164.
信息时代战场兵力组织的运作分析与设计 总被引：4，自引：0，他引：4
信息化战场空间、扁平化和网络化的兵力组织形式是未来网络中心战中作战部队编成的主要样式。为建立这一编成样式的设计方法和思路,以战场环境中兵力组织为例,分析了PCANS模型对信息时代组织测度的缺陷,在PCANS模型中引入信息因素描述组织的运作,并提出信息时代战场空间兵力组织设计的实质和目标以及设计方法。 相似文献
165.
166.
基于OPNET的战场IPV6通信网络拓扑设计及仿真 总被引：2，自引：0，他引：2
为了对IPv6与IPv4共存期间进行可靠通信提供技术上的参考,基于OPNET仿真平台,设计了几种不同的战场IPv6通信网络拓扑,强调了其特点和关键技术,突出了其仿真的主要参数配置,并通过分析仿真数据,对网络的有效性、实时性、可靠性等性能参数进行了评估,从而验证了所设计拓扑的可行性. 相似文献
167.
简单描述了舰空导弹引信发展的历程,介绍了它的基本工作原理。根据未来海战场环境的特点,分析了舰空导弹引信发展的总体需求。从提高导弹引信的引战配合、抗干扰能力、可靠性三大技术指标的角度,着重论述了舰空导弹引信的8个研究方向,探析了未来舰空导弹引信及相关的技术的发展趋势。对我国发展舰空导弹引信提出了建议。 相似文献
168.
Extending Sastry's result on the uncapacitated two‐commodity network design problem, we completely characterize the optimal solution of the uncapacitated K‐commodity network design problem with zero flow costs for the case when K = 3. By solving a set of shortest‐path problems on related graphs, we show that the optimal solutions can be found in O(n3) time when K = 3, where n is the number of nodes in the network. The algorithm depends on identifying a list of “basic patterns”; the number of basic patterns grows exponentially with K. We also show that the uncapacitated K‐commodity network design problem can be solved in O(n3) time for general K if K is fixed; otherwise, the time for solving the problem is exponential. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2004 相似文献
169.
Sungil Kim Heeyoung Kim Jye‐Chyi Lu Michael J. Casciato Martha A. Grover Dennis W. Hess Richard W. Lu Xin Wang 《海军后勤学研究》2015,62(2):127-142
In the field of nanofabrication, engineers often face unique challenges in resource‐limited experimental budgets, the sensitive nature of process behavior with respect to controllable variables, and highly demanding tolerance requirements. To effectively overcome these challenges, this article proposes a methodology for a sequential design of experiments through batches of experimental runs, aptly named Layers of Experiments with Adaptive Combined Design (LoE/ACD). In higher layers, where process behavior is less understood, experimental regions cover more design space and data points are more spread out. In lower layers, experimental regions are more focused to improve understanding of process sensitivities in a local, data‐rich environment. The experimental design is a combination of a space‐filling and an optimal design with a tuning parameter that is dependent on the amount of information accumulated over the various layers. The proposed LoE/ACD method is applied to optimize a carbon dioxide (epet‐CO2) assisted deposition process for fabricating silver nanoparticles with pressure and temperature variables. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 127–142, 2015 相似文献
170.
State‐level newborn screening allows for early treatment of genetic disorders, which can substantially improve health outcomes for newborns. As the cost of genetic testing decreases, it is becoming an essential part of newborn screening. A genetic disorder can be caused by many mutation variants; therefore, an important decision is to determine which variants to search for (ie, the panel design), under a testing budget. The frequency of variants that cause a disorder and the incidence of the disorder vary by racial/ethnic group. Consequently, it is important to consider equity issues in panel design, so as to reduce disparities among different groups. We study the panel design problem using cystic fibrosis (CF) as a model disorder, considering the trade‐offs between equity and accuracy, under a limited budget. Most states use a genetic test in their CF screening protocol, but panel designs vary, and, due to cost, no state's panel includes all CF‐causing variants. We develop models that design equitable genetic testing panels, and compare them with panels that maximize sensitivity in the general population. Our case study, based on realistic CF data, highlights the value of equitable panels and provides important insight for newborn screening practices. 相似文献