全文获取类型
| 收费全文 | 148篇 |
| 免费 | 1篇 |
| 国内免费 | 3篇 |
专业分类
| 152篇 |
出版年
| 2025年 | 2篇 |
| 2024年 | 4篇 |
| 2023年 | 2篇 |
| 2022年 | 1篇 |
| 2021年 | 4篇 |
| 2020年 | 5篇 |
| 2019年 | 4篇 |
| 2018年 | 3篇 |
| 2017年 | 7篇 |
| 2016年 | 10篇 |
| 2015年 | 5篇 |
| 2014年 | 10篇 |
| 2013年 | 24篇 |
| 2012年 | 11篇 |
| 2011年 | 12篇 |
| 2010年 | 8篇 |
| 2009年 | 5篇 |
| 2008年 | 5篇 |
| 2007年 | 8篇 |
| 2006年 | 3篇 |
| 2005年 | 3篇 |
| 2004年 | 2篇 |
| 2003年 | 4篇 |
| 2002年 | 3篇 |
| 2001年 | 4篇 |
| 2000年 | 1篇 |
| 1999年 | 1篇 |
| 1998年 | 1篇 |
排序方式： 共有152条查询结果，搜索用时 0 毫秒
141.
N+1式高频电力开关电源设计 总被引：3，自引：0，他引：3
探讨了N＋1式高频电力开关电源的组成和工作原理。开关电源由监控模块和整流模块组成,重点研究了均流技术和开关电源的抗干扰措施,论述了整流模块数量N＋1的选择。实际运行证明,N＋1式高频电力开关电源工作可靠,达到了预期效果。 相似文献
142.
Xue Li;Shilu Tong;Xiaoqiang Cai;Jian Chen; 《海军后勤学研究》2024,71(6):878-889
Online retail platforms have increasingly utilized big data technologies to gather demand information, which is then shared with upstream manufacturers employing various selling modes, including a hybrid format that encompasses both direct and indirect selling. Previous studies have suggested that platforms should refrain from sharing demand information with manufacturers engaged in indirect selling. In this study, we present a game-theoretic model to examine the factors influencing the online platform's decision to share information with an indirect selling manufacturer and under what conditions. Our initial analysis, considering exogenous selling formats in the base model, reveals that the platform's information sharing behavior is primarily influenced by selling format structures, commission fee rates, and competition intensity. The platform always has an incentive to share information with direct selling manufacturers; however, under a hybrid selling format, information sharing with indirect selling manufacturers may occur, particularly when both the commission fee rate and competition intensity are relatively high. We extend our investigation to explore the platform's optimal format-dependent information sharing behavior, accounting for manufacturers' endogenous selling format decisions, and demonstrate the robustness of our main findings from the base model. Overall, our research offers valuable insights and guidelines to assist online platforms in making informed decisions about their information sharing practices. 相似文献
143.
Emerging sharing modes, like the consumer-to-consumer (C2C) sharing of Uber and the business-to-consumer (B2C) sharing of GoFun, have considerably affected the retailing markets of traditional manufacturers, who are motivated to consider product sharing when making pricing and capacity decisions, particularly electric car manufacturers with limited capacity. In this paper, we examine the equilibrium pricing for a capacity-constrained manufacturer under various sharing modes and further analyze the impact of capacity constraint on the manufacturer's sharing mode selection as well as equilibrium outcomes. We find that manufacturers with low-cost products prefer B2C sharing while those with high-cost products prefer C2C sharing except when the sharing price is moderate. However, limited capacity motivates manufacturers to enter into the B2C sharing under a relatively low sharing price, and raise the total usage level by sharing high-cost products. We also show that the equilibrium capacity allocated to the sharing market with low-cost products first increases and then decreases. Finally, we find that sharing low-cost products with a high limited capacity leads to a lower retail price under B2C sharing, which creates a win-win situation for both the manufacturer and consumers. However, sharing high-cost products with a low limited capacity creates a win-lose situation for them. 相似文献
144.
Darrell Driver 《Defense & Security Analysis》2016,32(1):4-18
The US role in the North Atlantic Treaty Organization (NATO) Alliance is a 65-year history of retrenchment and renewal. When Washington has sought a retrenchment from the world, it traditionally increased burden sharing pressure on Europe to do more. During times of increased global ambition, the USA reaffirmed its traditional leadership role in the Alliance and its commitment to NATO effectiveness and relevance. This cycle of NATO retrenchment and renewal, however, is halting. Though the USA will continue to go through periods of relative increases and decreases in security policy ambition, signs point to a permanent defense and security retrenchment in Europe. Germany is the ally singularly capable of filling the resulting security gap. If NATO is to avoid the drift toward irrelevance many critics have predicted, Germany will need to cast off old inhibitions toward security and defense leadership. These trends and their implications for NATO's future are explored through historical case studies and the shifting contemporary security environment. 相似文献
145.
Marina Malamud 《Small Wars & Insurgencies》2018,29(2):245-268
This research paper analyzes the relationship between small wars, insurgency, and the natural environment. Existing literature and data are organized into four behavioral patterns: the resource-based wars accounts for the fight over natural resources; the warfare ecology paradigm refers to non-premeditated damage in preparation for as well as during and after conflicts; the environment as a target discusses intended attacks on the ecosystem; and the insurgency–climate intersection pattern denotes a deviation in climate change that increases the frequency of intergroup violence. The main premise is that small wars emerge when the ecosystem becomes a political asset. 相似文献
146.
Scheduling IT projects and assigning the project work to human resources are an important and common tasks in almost any IT service company. It is particularly complex because human resources usually have multiple skills. Up to now only little work has considered IT‐specific properties of the project structure and human resources. In this article, we present an optimization model that simultaneously schedules the activities of multiple IT projects with serial network structures and assigns the project work to multiskilled internal and external human resources with different efficiencies. The goal is to minimize costs. We introduce a metaheuristic that decomposes the problem into a binary scheduling problem and a continuous staffing problem where the latter is solved efficiently by exploiting its underlying network structure. For comparison, we solve the mixed–binary linear program with a state–of–the–art commercial solver. The impacts of problem parameters on computation time and solution gaps between the metaheuristic and the solver are assessed in an experimental study. Our results show that the metaheuristic provides very favorable results in considerable less time than the solver for midsize problems. For larger problems, it shows a similar performance while the solver fails to return feasible solutions. © 2012 Wiley Periodicals, Inc. Naval Research Logistics 59: 111–127, 2012 相似文献
147.
Binyam Solomon 《Defence and Peace Economics》2013,24(4):323-326
This note implements the sensitivity analysis suggested by Sandler and re‐examines the robustness of the concordance between NATO benefits and burdens. 相似文献
148.
Todd Sandler† 《Defence and Peace Economics》2013,24(4):317-321
This note refutes criticism raised by Solomon about past tests used to ascertain the concordance between NATO benefits and burdens. In so doing, a case is made for keeping the benefit proxy based on exposed borders. Moreover, a truer sensitivity analysis than that offered by Solomon is suggested. 相似文献
149.
As a result of allied subsidy and the influence of sunk costs, the marginal cost of the Gulf War to the US was reduced to negligible size. This result is at variance with the Olson‐Zeckhauser thesis that in an alliance “the small exploit the large.” A game theoretic alternative explanation suggests that the relation between allies resembles the game of Chicken, successfully played by the US. The ability to shift the marginal costs of war in the short term raises questions about the possible underestimation of long term effects. 相似文献
150.
HÅKAN FRIMAN 《African Security Review》2013,22(3):62-77
The armed conflict in the DRC has been characterised by appalling, widespread and systematic human rights violations. It varies from civil war to a war between national armies. Much of the conflict falls between these two categories due to the involvement of foreign troops in civil strife, as well as foreign rebel groups fighting their home government's troops but on Congolese soil. The most pressing need is to cease hostilities and address the humanitarian situation in the country. Questions of justice and accountability, and issues relating to the rule of law will have to be addressed soon in order to achieve a durable peace in the country and in the region. Since there are links between different conflicts in the region, a broader solution should preferably be found. However, this would further complicate an already difficult proposition. Efforts limited to the DRC would be more feasible and could lead to similar measures in other conflict ridden countries in the region. This essay therefore discusses the available processes for justice. 相似文献