全文获取类型
收费全文 | 2800篇 |
免费 | 373篇 |
国内免费 | 33篇 |
专业分类
化学 | 1篇 |
晶体学 | 1篇 |
力学 | 2篇 |
综合类 | 42篇 |
数学 | 467篇 |
物理学 | 102篇 |
无线电 | 2591篇 |
出版年
2024年 | 11篇 |
2023年 | 40篇 |
2022年 | 41篇 |
2021年 | 51篇 |
2020年 | 72篇 |
2019年 | 55篇 |
2018年 | 53篇 |
2017年 | 74篇 |
2016年 | 101篇 |
2015年 | 120篇 |
2014年 | 181篇 |
2013年 | 228篇 |
2012年 | 185篇 |
2011年 | 216篇 |
2010年 | 184篇 |
2009年 | 205篇 |
2008年 | 164篇 |
2007年 | 235篇 |
2006年 | 188篇 |
2005年 | 138篇 |
2004年 | 157篇 |
2003年 | 132篇 |
2002年 | 101篇 |
2001年 | 95篇 |
2000年 | 51篇 |
1999年 | 28篇 |
1998年 | 22篇 |
1997年 | 16篇 |
1996年 | 13篇 |
1995年 | 10篇 |
1994年 | 6篇 |
1993年 | 7篇 |
1992年 | 9篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 8篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有3206条查询结果,搜索用时 15 毫秒
211.
212.
213.
基于认知的无线传感器网络抗干扰路由算法 总被引:2,自引:0,他引:2
针对无线传感器网络受Wi—Fi等异构系统干扰日益严重的问题,在引入基于簇的动态多信道组网策略的基础上,综合考虑频谱受干扰程度、信道切换代价、节点剩余能量等因素,提出了一种认知频谱干扰的能量有效的路由(CSIEE)算法。仿真结果表明,该路由与EEPA,AODV,AODV—EA路由相比,有效地节约了传感器节点能量,延长了网络生命周期。 相似文献
214.
This article puts forward a novel routing architecture for complex optical network,which core component is path calculation element(PCE).As is well known,the PCE-based distributed path computation structure is making the routing control and computation loosely coupled from traditional control plane.In the study,the resource allocation and routing algorithm are the critical part of PCE hierarchy.To compare the performance of new architecture and the traditional one,the user uses the flooding suppression,routing delay,resource utilization and traffic blocking probability as performance simulation parameters and taking the verification simulation on objective modular network testbed(OMNeT)platform against to source-node routing architecture.The numerical analysis,computer simulation and experiment work indicate that the operation of PCE-based routing architecture can reduce the flooding information of path calculation request as well as the routing hops significantly and improve the quality of service(QoS)by decreasing the blocking probability when failure happened. 相似文献
215.
This article puts forward an Ad-hoc on-demand distance vector routing(AODV)routing overhead analysis method in mobile Ad-hoc network(MANET).Although multiple routing protocols have been proposed to improve the performance,scarcely any paper analyzed the routing overhead caused by routing setup and maintenance processes in mathematical way.Routing overhead consumes part of network resources and limits the supported traffic in the network.For on-demand routing protocols like AODV,the routing overhead depends on the link failure probability to a great extent.This article analyzes the collision probability caused by hidden-node problem and the impact on link failure probability.In chain and rectangle scenarios,it presents a mathematical analysis of the theoretical routing overhead of AODV protocol based on link failure probability.Simulations on OPNET 14.5platform match well with the theoretical derivation which confirms the effectiveness of the analysis method. 相似文献
216.
The varying population density leads to imbalanced utilization rate of satellites. To ensure an intelligent engineering of traffic over satellite networks, a distributed routing scheme for single-layered satellite network, load balancing routing protocol based on mobile agent (LBRP-MA) is proposed. For LBRP-MA, mobile agents explore route by migrating autonomously. Upon arriving at destination, mobile agents migrate back. On each intermediate satellite, mobile agents evaluate path cost considering satellite geographical position as well as inter-satellite link (ISL) cost, and finally take ISL congestion index into account to update routing tables. Through simulations on the Courier-like constellation, the proposed approach is shown to achieve guaranteed end-to-end delay bound and decrease packet loss ratio with better throughput, which is especially suitable for data transferring in case of high traffic load. Moreover, results of the complexity analysis demonstrate that LBRP-MA can have low onboard signaling, storage and computation requirements. Furthermore, issues of LBRP-MA such as ISL congestion index and cost modification factor are discussed. 相似文献
217.
Chord算法是一种典型的结构化P2P搜索算法,该算法简洁而且拓扑结构清晰,但该算法还存在着路由表信息冗余,查找效率不高的问题。在分析经典Chord算法的基础上,通过扩展Chord路由表,提出一种新的查找算法,该算法能够消除路由表的一些冗余信息,减少查找次数。通过理论分析,该算法提高了Chord的查找效率。 相似文献
218.
219.
220.