全文获取类型
收费全文 | 10581篇 |
免费 | 806篇 |
国内免费 | 456篇 |
专业分类
电工技术 | 533篇 |
技术理论 | 1篇 |
综合类 | 797篇 |
化学工业 | 1820篇 |
金属工艺 | 619篇 |
机械仪表 | 659篇 |
建筑科学 | 862篇 |
矿业工程 | 316篇 |
能源动力 | 244篇 |
轻工业 | 655篇 |
水利工程 | 207篇 |
石油天然气 | 764篇 |
武器工业 | 166篇 |
无线电 | 1107篇 |
一般工业技术 | 1173篇 |
冶金工业 | 485篇 |
原子能技术 | 105篇 |
自动化技术 | 1330篇 |
出版年
2024年 | 58篇 |
2023年 | 190篇 |
2022年 | 279篇 |
2021年 | 412篇 |
2020年 | 313篇 |
2019年 | 268篇 |
2018年 | 282篇 |
2017年 | 335篇 |
2016年 | 283篇 |
2015年 | 402篇 |
2014年 | 486篇 |
2013年 | 586篇 |
2012年 | 611篇 |
2011年 | 706篇 |
2010年 | 564篇 |
2009年 | 527篇 |
2008年 | 497篇 |
2007年 | 517篇 |
2006年 | 580篇 |
2005年 | 511篇 |
2004年 | 326篇 |
2003年 | 334篇 |
2002年 | 307篇 |
2001年 | 334篇 |
2000年 | 295篇 |
1999年 | 315篇 |
1998年 | 305篇 |
1997年 | 224篇 |
1996年 | 195篇 |
1995年 | 208篇 |
1994年 | 150篇 |
1993年 | 98篇 |
1992年 | 89篇 |
1991年 | 63篇 |
1990年 | 42篇 |
1989年 | 35篇 |
1988年 | 35篇 |
1987年 | 26篇 |
1986年 | 15篇 |
1985年 | 8篇 |
1984年 | 8篇 |
1983年 | 9篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1980年 | 6篇 |
1979年 | 1篇 |
1972年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
Haojie Li Yue Guan Lijuan Liu Fanglin Wang Ling Wang 《Multimedia Tools and Applications》2016,75(15):8939-8954
As a new information sharing platform, microblog has got explosive growth in recent years and has become an important source for public opinion mining. A variety of information like the reviews of brands/products or the trends of events can be socially sensed from such kind of data. However, it is still a challenging task to search relevant microblogs as the user generated content tends to be mixed with noise. Besides short text, image is getting popular in microblogs due to its power in visual information conveying. In this paper, we leverage textual and visual cues integratedly and propose a general re-ranking approach for microblog retrieval via multi-graph semi-supervised learning. We argue that the different types of information in microblogs correspond to different relationships among microblogs and each type of the relationship can be represented as a similarity graph. We then integrate different graphs into a unified framework and solve them simultaneously for microblog re-ranking. Extensive experiments on a recently published Brand-Social-Net dataset showed the effectiveness of the proposed method and marginal improvements have been achieved in accuracy as compared to the single graph model based method. 相似文献
82.
针对城市给水管线不同管段在灾后对于管网整体可靠度影响的差异性,为了能够较好地评价不同管段对管网系统连接可靠度的贡献,引入失效概率重要度和关键重要度,建立了基于历史经验方法的管网可靠度及管线失效概率重要度、关键重要度计算模型。实例计算结果表明,该模型计算的管网连接可靠度结果与其他文献方法的计算结果基本一致,验证了模型的合理性、有效性。进而应用该模型计算出各段管线的失效概率重要度、关键重要度,对管线防灾等级划分,给出了管网分割方法与管网震后恢复策略。研究结果为编制给水管网抗震防灾规划、震后管网恢复计划及制定出相应的抗灾应急措施提供依据。 相似文献
83.
本文介绍了一种基于 AM186 EM 处理器的地址空间优化应用,当系统需要处理器支持的最大容量内存时, FLASH 和外围存储器(例如双口 RAM等)可以共用处理器的UCS选通信号,从而实现 FLASH 和外围存储器共用尽可能大的地址空间。同样,当系统需要最大容量的FLASH 时,内存 RAM和外围存储器可以共用处理器的LCS选通信号,从而实现 RAM和外围存储器共用尽可能大的地址空间。 相似文献
84.
Peng Qin Bin Dai Guan Xu Kui Wu Benxiong Huang 《Peer-to-Peer Networking and Applications》2016,9(6):1047-1059
A Peer-to-Peer (P2P) network can boost its performance if peers are provided with underlying network-layer routing topology. The task of inferring the network-layer routing topology and link performance from an end host to a set of other hosts is termed as network tomography, and it normally requires host computers to send probing messages. We design a passive network tomography method that does not require any probing messages and takes a free ride over data flows in P2P networks. It infers routing topology based on end-to-end delay correlation estimation (DCE) without requiring any synchronization or cooperation from the intermediate routers. We implement and test our method in the real world Internet environment and achieved the accuracy of 92 % in topology recovery. We also perform extensive simulation in OMNeT++ to evaluate its performance over large scale networks, showing that its topology recovery accuracy is about 95 % for large networks. 相似文献
85.
86.
Xuechong Guan Yongming Li Feng Feng 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2013,17(1):63-70
In this paper, a new order relation on fuzzy soft sets, called soft information order, is introduced and its application to decision-making is investigated. It is shown that the collection of all fuzzy soft sets (over a given universe set), equipped with this new order, forms a complete Heyting algebra. The representation theorem of fuzzy soft sets with respect to the soft information order is also obtained. We initiate the concepts of soft set satisfaction problems and their solutions. An algorithm is presented to solve such decision-making problems. 相似文献
87.
88.
Guang-Song Han Zhi-Hong Guan Xin-Ming Cheng Yonghong Wu Feng Liu 《International Journal of Control, Automation and Systems》2013,11(6):1122-1127
A novel multiconsensus problem is introduced in multiagent systems. The states of multiple agents in each subnetwork asymptotically converge to a consistent value with information exchanges among subnetworks. The multiconsensus problem of second order multiagent systems with directed topologies is studied. Three linear protocols are proposed to solve the multiconsensus problem. Necessary and sufficient conditions are derived based on matrix theory. Simulations are provided to demonstrate the effectiveness of the theoretical results. 相似文献
89.
内容管理在企业信息管理领域中已成为非结构化或半结构化的数字资源的采集、管理、利用和传递,并能有机集成到结构化数据的智能环境中的主要解决方案,从而使得企业内容管理更加完整有效;因此,笔者认为,内容管理系统在企业内容管理集成模型中的应用将是以非结构化信息为主的企业级内容信息系统建设的有效解决方案. 相似文献
90.
The job shop scheduling problem (JSP) is one of the most notoriously intractable NP-complete optimization problems. Over the last 10–15 years, tabu search (TS) has emerged as an effective algorithmic approach for the JSP. However, the quality of solutions found by tabu search approach depends on the initial solution. To overcome this problem and provide a robust and efficient methodology for the JSP, the heuristics search approach combining simulated annealing (SA) and TS strategy is developed. The main principle of this approach is that SA is used to find the elite solutions inside big valley (BV) so that TS can re-intensify search from the promising solutions. This hybrid algorithm is tested on the standard benchmark sets and compared with the other approaches. The computational results show that the proposed algorithm could obtain the high-quality solutions within reasonable computing times. For example, 17 new upper bounds among the unsolved problems are found in a short time. 相似文献