全文获取类型
收费全文 | 260788篇 |
免费 | 20362篇 |
国内免费 | 13192篇 |
专业分类
电工技术 | 16725篇 |
技术理论 | 51篇 |
综合类 | 36206篇 |
化学工业 | 28504篇 |
金属工艺 | 9644篇 |
机械仪表 | 14030篇 |
建筑科学 | 37343篇 |
矿业工程 | 14869篇 |
能源动力 | 7948篇 |
轻工业 | 14502篇 |
水利工程 | 13912篇 |
石油天然气 | 11125篇 |
武器工业 | 2493篇 |
无线电 | 16805篇 |
一般工业技术 | 18399篇 |
冶金工业 | 15388篇 |
原子能技术 | 2618篇 |
自动化技术 | 33780篇 |
出版年
2024年 | 799篇 |
2023年 | 2464篇 |
2022年 | 4741篇 |
2021年 | 5700篇 |
2020年 | 6052篇 |
2019年 | 5081篇 |
2018年 | 4803篇 |
2017年 | 5788篇 |
2016年 | 6943篇 |
2015年 | 7789篇 |
2014年 | 14444篇 |
2013年 | 13144篇 |
2012年 | 17156篇 |
2011年 | 18278篇 |
2010年 | 14562篇 |
2009年 | 15213篇 |
2008年 | 14237篇 |
2007年 | 18724篇 |
2006年 | 17772篇 |
2005年 | 15574篇 |
2004年 | 13273篇 |
2003年 | 11984篇 |
2002年 | 9889篇 |
2001年 | 8351篇 |
2000年 | 7050篇 |
1999年 | 5758篇 |
1998年 | 4354篇 |
1997年 | 3824篇 |
1996年 | 3541篇 |
1995年 | 3007篇 |
1994年 | 2674篇 |
1993年 | 2005篇 |
1992年 | 1781篇 |
1991年 | 1325篇 |
1990年 | 1156篇 |
1989年 | 1020篇 |
1988年 | 818篇 |
1987年 | 565篇 |
1986年 | 424篇 |
1985年 | 352篇 |
1984年 | 329篇 |
1983年 | 240篇 |
1982年 | 215篇 |
1981年 | 165篇 |
1980年 | 131篇 |
1979年 | 110篇 |
1978年 | 62篇 |
1977年 | 72篇 |
1976年 | 55篇 |
1975年 | 55篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Output feedback controller for polytopic systems exploiting the direct searching of the design space
This paper deals with the problem of designing a robust static output feedback controller for polytopic systems. The current research that tackled this problem is mainly based on LMI method, which is conservative by nature. In this paper, a novel approach is proposed, which considers the design space of the controller parameters and iteratively partitions the space to small simplexes. Then, by assessing the stability in each simplex, the solution space for design parameters is directly determined. It has been theoretically proved that, if there exists a feasible solution in the design space, the algorithm can find it. To validate the result of the proposed approach, comparative simulation examples are given to illustrate the performance of the design methodology as compared to those of previous approaches. 相似文献
32.
Most real-world vehicle nodes can be structured into an interconnected network of vehicles. Through structuring these services and vehicle device interactions into multiple types, such internet of vehicles becomes multidimensional heterogeneous overlay networks. The heterogeneousness of the overlays makes it difficult for the overlay networks to coordinate with each other to improve their performance. Therefore, it poses an interesting but critical challenge to the effective analysis of heterogeneous virtual vehicular networks. A variety of virtual vehicular networks can be easily deployed onto the native network by applying the concept of SDN (Software Defined Networking). These virtual networks reflect their heterogeneousness due to their different performance goals, and they compete for the same physical resources of the underlying network, so that a sub-optimal performance of the virtual networks may be achieved. Therefore, we propose a Deep Reinforcement Learning (DRL) approach to make the virtual networks cooperate with each other through the SDN controller. A cooperative solution based on the asymmetric Nash bargaining is proposed for co-existing virtual networks to improve their performance. Moreover, the Markov Chain model and DRL resolution are introduced to leverage the heterogeneous performance goals of virtual networks. The implementation of the approach is introduced, and simulation results confirm the performance improvement of the latency sensitive, loss-rate sensitive and throughput sensitive heterogeneous vehicular networks using our cooperative solution. 相似文献
33.
Fog computing has emerged to support the requirements of IoT applications that could not be met by today’s solutions. Different initiatives have been presented to drive the development of fog, and much work has been done to improve certain aspects. However, an in-depth analysis of the different solutions, detailing how they can be integrated and applied to meet specific requirements, is still required. In this work, we present a unified architectural model and a new taxonomy, by comparing a large number of solutions. Finally, we draw some conclusions and guidelines for the development of IoT applications based on fog. 相似文献
34.
本文以云杉八齿小蠹Ips typographus Linnaeus为例,经标本选取,观察虫体整体形态,绘制整体结构草图,电子显微镜观察局部、得到局部数字图像,分别建立虫体每一部分的高精度细节。把模型每部分拼装在一起组成整体模型,构建出了云杉八齿小蠹三维虚拟昆虫数字化模型。 相似文献
35.
36.
冯鹏一 《信息通信技术与政策》2020,(1):12-15
以电信用户入网协议为切入点,电信用户的携号转网行为应受到《合同法》《消费者权益保护法》等私法规范的保护与限制。该行为引起的格式条款解释、合同终止、违约责任、损失赔偿等问题,不能仅靠《电信条例》等公法规范来调整。应当积极引导广大消费者用户以私法领域相关规定为依据,转变争议解决思维,拓宽纠纷处理途径,合理选择维权手段,以保护自身合法民事权益,与行业监管部门共同推动电信行业有序发展。 相似文献
37.
38.
39.
40.
A small handful of recent studies have addressed a phenomenon known as “phantom vibration syndrome”. This refers to when phone users perceive their device to vibrate, indicating that a call or text is incoming, when in fact the phone did not vibrate at all. Though these studies show that most users do not find phantom vibration hallucinations to be very bothersome, they also find that a large majority of users experience this phenomenon. This paper explores what the striking prevalence of phantom vibration syndrome means for our contemporary relationships with technology. I begin with a review of the theories purporting to explain these data, which largely rely on particular understandings of the brain. Next I develop an alternative theory of phantom vibration syndrome based on insights from the philosophical tradition of phenomenology. This account considers the ways users develop bodily and perceptual habits regarding how the phone is understood and used. By critically contrasting these different theories, we can refine our questions about what the high prevalence of phantom vibration syndrome implies about our contemporary technological situation. 相似文献