全文获取类型
收费全文 | 1362篇 |
免费 | 41篇 |
国内免费 | 9篇 |
专业分类
电工技术 | 46篇 |
化学工业 | 303篇 |
金属工艺 | 49篇 |
机械仪表 | 32篇 |
建筑科学 | 21篇 |
能源动力 | 56篇 |
轻工业 | 60篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 218篇 |
一般工业技术 | 309篇 |
冶金工业 | 117篇 |
原子能技术 | 14篇 |
自动化技术 | 185篇 |
出版年
2023年 | 11篇 |
2022年 | 42篇 |
2021年 | 64篇 |
2020年 | 32篇 |
2019年 | 39篇 |
2018年 | 49篇 |
2017年 | 38篇 |
2016年 | 33篇 |
2015年 | 29篇 |
2014年 | 37篇 |
2013年 | 69篇 |
2012年 | 54篇 |
2011年 | 61篇 |
2010年 | 59篇 |
2009年 | 56篇 |
2008年 | 68篇 |
2007年 | 62篇 |
2006年 | 53篇 |
2005年 | 43篇 |
2004年 | 25篇 |
2003年 | 32篇 |
2002年 | 27篇 |
2001年 | 22篇 |
2000年 | 15篇 |
1999年 | 23篇 |
1998年 | 51篇 |
1997年 | 36篇 |
1996年 | 25篇 |
1995年 | 23篇 |
1994年 | 14篇 |
1993年 | 21篇 |
1992年 | 9篇 |
1991年 | 14篇 |
1990年 | 17篇 |
1989年 | 13篇 |
1988年 | 15篇 |
1987年 | 6篇 |
1986年 | 7篇 |
1985年 | 10篇 |
1984年 | 10篇 |
1983年 | 10篇 |
1982年 | 6篇 |
1981年 | 7篇 |
1980年 | 7篇 |
1979年 | 12篇 |
1978年 | 12篇 |
1977年 | 7篇 |
1976年 | 6篇 |
1974年 | 7篇 |
1973年 | 10篇 |
排序方式: 共有1412条查询结果,搜索用时 15 毫秒
81.
The Highway Loss Data Institute (HLDI) compiles injury and collision claim information from major insurance companies. These data have indicated that a disproportionately large number of injury claims are made for small cars. As a result, it might be concluded that small cars increase injury risk to their occupants. Recent advertisements by a major automobile manufacturer suggest a similar conclusion should be drawn from these data. In this paper it is shown that the apparent higher injury risk attributed to small cars can reflect the behavior of persons driving small cars. The number of injury claim accidents per collision claim accident is examined as an alternative measure of injury risk. Possible problems in interpretation are discussed. 相似文献
82.
83.
Journal of Materials Science - 相似文献
84.
Krishnan H Garth C Gühring J Gülsün MA Greiser A Joy KI 《IEEE transactions on visualization and computer graphics》2012,18(6):966-977
Many flow visualization techniques, especially integration-based methods, are problematic when the measured data exhibit noise and discretization issues. Particularly, this is the case for flow-sensitive phase-contrast magnetic resonance imaging (PC-MRI) data sets which not only record anatomic information, but also time-varying flow information. We propose a novel approach for the visualization of such data sets using integration-based methods. Our ideas are based upon finite-time Lyapunov exponents (FTLE) and enable identification of vessel boundaries in the data as high regions of separation. This allows us to correctly restrict integration-based visualization to blood vessels. We validate our technique by comparing our approach to existing anatomy-based methods as well as addressing the benefits and limitations of using FTLE to restrict flow. We also discuss the importance of parameters, i.e., advection length and data resolution, in establishing a well-defined vessel boundary. We extract appropriate flow lines and surfaces that enable the visualization of blood flow within the vessels. We further enhance the visualization by analyzing flow behavior in the seeded region and generating simplified depictions. 相似文献
85.
时变滞后Lurie型系统的改进稳定性准则 总被引:1,自引:0,他引:1
In this technical note, we present a new stability analysis procedure for ascertaining the delay-dependent stability of a class of Lurie systems with time-varying delay and sector-bounded nonlinearity using Lyapunov-Krasovskii (LK) functional approach. The proposed analysis, owing to the candidate LK functional and tighter bounding of its time-derivative, yields less conservative absolute and robust stability criteria for nominal and uncertain systems respectively. The effectiveness of the proposed criteria over some of the recently reported results is demonstrated using a numerical example. 相似文献
86.
Thomas Ball Christopher Colby Peter Danielsen Lalita Jategaonkar Jagadeesan Radha Jagadeesan Konstantin Läufer Peter Mataga Kenneth Rehor 《International Journal of Speech Technology》2000,3(2):93-108
Modern interactive services such as information and e-commerce services are becoming increasingly more flexible in the types of user interfaces they support. These interfaces incorporate automatic speech recognition and natural language understanding and include graphical user interfaces on the desktop and web-based interfaces using applets and HTML forms. To what extent can the user interface software be decoupled from the service logic software (the code that defines the essential function of a service)? Decoupling of user interface from service logic directly impacts the flexibility of services, or how easy they are to modify and extend. To explore these issues, we have developed Sisl, an architecture and domain-specific language for designing and implementing interactive services with multiple user interfaces. A key principle underlying Sisl is that all user interfaces to a service share the same service logic. Sisl provides a clean separation between the service logic and the software for a variety of interfaces, including Java applets, HTML pages, speech-based natural language dialogue, and telephone-based voice access. Sisl uses an event-based model of services that allows service providers to support interchangeable user interfaces (or add new ones) to a single consistent source of service logic and data. As part of a collaboration between research and development, Sisl is being used to prototype a new generation of call processing services for a Lucent Technologies switching product. 相似文献
87.
Wireless Personal Communications - In the recent past, the Cognitive Radio Network (CRN) plays significant role in mobile technology for energy efficient wireless 5G communication. The Non... 相似文献
88.
Krishnan Venkataraman Sandhya Khurana T. C. Tai 《International journal of molecular sciences》2013,14(9):17897-17925
Oxidative damage is considered to be the primary cause of several aging associated disease pathologies. Cumulative oxidative damage tends to be pervasive among cellular macromolecules, impacting proteins, lipids, RNA and DNA of cells. At a systemic level, events subsequent to oxidative damage induce an inflammatory response to sites of oxidative damage, often contributing to additional oxidative stress. At a cellular level, oxidative damage to mitochondria results in acidification of the cytoplasm and release of cytochrome c, causing apoptosis. This review summarizes findings in the literature on oxidative stress and consequent damage on cells and tissues of the cardiovascular system and the central nervous system, with a focus on aging-related diseases that have well-documented evidence of oxidative damage in initiation and/or progression of the disease. The current understanding of the cellular mechanisms with a focus on macromolecular damage, impacted cellular pathways and gross morphological changes associated with oxidative damage is also reviewed. Additionally, the impact of calorific restriction with its profound impact on cardiovascular and neuronal aging is addressed. 相似文献
89.
90.
Campbell J.P. Lenahan P.M. Krishnan A.T. Krishnan S. 《Device and Materials Reliability, IEEE Transactions on》2006,6(2):117-122
A combination of MOSFET gate-controlled diode measurements and a very sensitive electron spin resonance technique called spin-dependent recombination was utilized to observe and identify defect centers generated by a negative bias temperature stress in fully processed SiO/sub 2/-based pMOSFETs. In SiO/sub 2/ devices, the defects include two Si/SiO/sub 2/ interface silicon dangling bond centers (P/sub b0/ and P/sub b1/) and may also include an oxide silicon dangling bond center (E'). The observations indicate that both P/sub b0/ and P/sub b1/ defects play major roles in these SiO/sub 2/-based devices and suggest that E' centers could play an important role. 相似文献