全文获取类型
收费全文 | 3427篇 |
免费 | 97篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 61篇 |
综合类 | 6篇 |
化学工业 | 1044篇 |
金属工艺 | 66篇 |
机械仪表 | 36篇 |
建筑科学 | 208篇 |
矿业工程 | 31篇 |
能源动力 | 41篇 |
轻工业 | 417篇 |
水利工程 | 12篇 |
石油天然气 | 4篇 |
无线电 | 173篇 |
一般工业技术 | 464篇 |
冶金工业 | 500篇 |
原子能技术 | 39篇 |
自动化技术 | 426篇 |
出版年
2022年 | 32篇 |
2021年 | 39篇 |
2020年 | 30篇 |
2019年 | 34篇 |
2018年 | 53篇 |
2017年 | 47篇 |
2016年 | 73篇 |
2015年 | 90篇 |
2014年 | 88篇 |
2013年 | 127篇 |
2012年 | 129篇 |
2011年 | 167篇 |
2010年 | 113篇 |
2009年 | 125篇 |
2008年 | 126篇 |
2007年 | 146篇 |
2006年 | 124篇 |
2005年 | 120篇 |
2004年 | 107篇 |
2003年 | 75篇 |
2002年 | 73篇 |
2001年 | 55篇 |
2000年 | 60篇 |
1999年 | 62篇 |
1998年 | 128篇 |
1997年 | 89篇 |
1996年 | 95篇 |
1995年 | 73篇 |
1994年 | 77篇 |
1993年 | 62篇 |
1992年 | 54篇 |
1991年 | 49篇 |
1990年 | 40篇 |
1989年 | 45篇 |
1988年 | 28篇 |
1987年 | 38篇 |
1986年 | 33篇 |
1985年 | 45篇 |
1984年 | 36篇 |
1983年 | 40篇 |
1982年 | 36篇 |
1981年 | 32篇 |
1980年 | 35篇 |
1978年 | 27篇 |
1977年 | 38篇 |
1976年 | 43篇 |
1975年 | 42篇 |
1974年 | 22篇 |
1973年 | 28篇 |
1970年 | 31篇 |
排序方式: 共有3528条查询结果,搜索用时 15 毫秒
21.
We address the problem of multi-label classification in heterogeneous graphs, where nodes belong to different types and different
types have different sets of classification labels. We present a novel approach that aims to classify nodes based on their
neighborhoods. We model the mutual influence of nodes as a random walk in which the random surfer aims at distributing class
labels to nodes while walking through the graph. When viewing class labels as “colors”, the random surfer is essentially spraying
different node types with different color palettes; hence the name Graffiti of our method. In contrast to previous work on
topic-based random surfer models, our approach captures and exploits the mutual influence of nodes of the same type based
on their connections to nodes of other types. We show important properties of our algorithm such as convergence and scalability.
We also confirm the practical viability of Graffiti by an experimental study on subsets of the popular social networks Flickr and LibraryThing. We demonstrate the superiority of our approach by comparing it to three other state-of-the-art techniques for graph-based
classification. 相似文献
22.
23.
Studies of the microstructure of porous solids by physisorption measurements . The principal experimental methods for studying the microstructure of porous solids are based on physisorption measurements. The resulting sorption isotherms can yield data such as surface area and pore radius distribution, which are of great importance for development and characterization of porous catalysts. After a brief presentation of available measuring equipment, the main concern of this survey is the evaluation of sorption isotherms. In particular, methods for determining the micropore contribution to the total pore volume and the pore radius distribution in the micropore range are examined critically with regard to their reliability. 相似文献
24.
25.
Cholesterol 5α,6α-epoxide (α-epoxide) and cholesterol 5β,6β-epoxide (β-epoxide) were individually suspended in simulated gastric
juice (pH 1.2) at 37 C, and their reaction was followed by gradient high performance liquid chromatography (HPLC) with flame
ionization (FID) detection. Both epoxides reacted rapidly in the aqueous acid medium. The α-epoxide formed 6β-chlorocholestane-3β,5α-diol
(α-chlorohydrin) and 5α-cholestane-3β,5,6β-triol (triol), while the β-epoxide formed 5α-chlorocholestane-3β,6β-diol (β-chlorohydrin)
and triol. The isomeric chlorohydrins reacted further to form the triol. In mildly alkaline aqueous medium, each chlorohydrin
reverted to the epoxide from which it was formed. The data suggest that both epoxides, which have been reported to have adverse
health effects in animals, would be largely hydrolyzed in the stomach and to the triol, which also has been reported to have
biological activity. The data furher suggest that residual chlorohydrins surviving stomach residence can be expected to revert
to epoxide in the more alkaline intestinal environment. 相似文献
26.
Michael?HardeggerEmail author Daniel?Roggen Gerhard?Tr?ster 《Personal and Ubiquitous Computing》2015,19(1):123-141
We present 3D ActionSLAM, a stand-alone wearable system that can track people in previously unknown multi-floor environments with sub-room accuracy. ActionSLAM stands for action-based simultaneous localization and mapping: It fuses dead reckoning data from a foot-mounted inertial measurement unit with the recognition of location-related actions to build and update a local landmark map. Simultaneously, this map compensates for position drift errors that accumulate in open-loop tracking by means of a particle filter. To evaluate the system performance, we analyzed 23 tracks with a total walked distance of 6,489 m in buildings with up to three floors. The algorithm robustly (93 % of runs converged) mapped the areas with a mean landmark positioning error of 0.59 m. As ActionSLAM is fully stand-alone and not dependent on external infrastructure, it is well suited for patient tracking in remote health care applications. The algorithm is computationally light-weight and runs in real-time on a Samsung Galaxy S4, enabling immediate location-aware feedback. Finally, we propose visualization techniques to facilitate the interpretation of tracking data acquired with 3D ActionSLAM. 相似文献
27.
We study a motion planning problem where items have to be transported from the top room of a tower to the bottom of the tower, while simultaneously other items have to be transported in the opposite direction. Item sets are moved in two baskets hanging on a rope and pulley. To guarantee stability of the system, the weight difference between the contents of the two baskets must always stay below a given threshold. We prove that it is $\varPi_{2}^{p}$ -complete to decide whether some given initial situation of the underlying discrete system can lead to a given goal situation. Furthermore we identify several polynomially solvable special cases of this reachability problem, and we also settle the computational complexity of a number of related questions. 相似文献
28.
Cornelia Kappeler-Setz Franz Gravenhorst Johannes Schumm Bert Arnrich Gerhard Tröster 《Personal and Ubiquitous Computing》2013,17(2):261-271
Manic depression, also known as bipolar disorder, is a common and severe form of mental disorder. The European research project MONARCA aims at developing and validating mobile technologies for multi-parametric, long term monitoring of physiological and behavioral information relevant to bipolar disorder. One aspect of MONARCA is to investigate the long term monitoring of Electrodermal activity (EDA) to support the diagnosis and treatment of bipolar disorder patients. EDA is known as an indicator of the emotional state and the stress level of a person. To realize a long-term monitoring of the EDA, the integration of the sensor system in the shoe or sock is a promising approach. This paper presents a first step towards such a sensor system. In a feasibility study including 8 subjects, we investigate the correlation between EDA measurements at the fingers, which is the most established sensing site, with measurements of the EDA at the feet. The results indicate that 88% of the evoked skin conductance responses (SCRs) occur at both sensing sites. When using an action movie as psychophysiologically activating stimulus, we have found weaker reactivity in the foot than in the hand EDA. The results also suggest that the influence of moderate physical activity on EDA measurements is low and has a similar effect for both recording sites. This suggests that the foot recording location is suitable for recordings in daily life even in the presence of moderate movement. 相似文献
29.
TeraGrid Science Gateways and Their Impact on Science 总被引:1,自引:0,他引:1
Wilkins-Diehr Nancy Gannon Dennis Klimeck Gerhard Oster Scott Pamidighantam Sudhakar 《Computer》2008,41(11):32-41
The Science Gateways program seeks to provide researchers with easy access to TeraGrid's high-performance computing resources. A look at four successful gateways illustrates the program's goals, challenges, and opportunities. 相似文献
30.
Stella Clarke Gerhard Schillhuber Michael F. Zaeh Heinz Ulbrich 《Multimedia Systems》2008,13(4):253-261
The remote nature of telepresence scenarios can be seen as a strongpoint and also as a weakness. Although it enables the remote
control of robots in dangerous or inaccessible environments, it necessarily involves some kind of communication mechanism
for the transmission of control signals. This communication mechanism necessarily involves adverse network effects such as
delay. Three mechanisms aimed at improving the effects of network delay are presented in this paper: (1) Motion prediction
to partially compensate for network delays, (2) force prediction to learn a local force model, thereby reducing dependency
on delayed force signals, and (3) haptic data compression to reduce the required bandwidth of high frequency data. The utilized
motion prediction scheme was shown to improve operator performance, but had no influence on operator immersion. The force
prediction provided haptic feedback through synchronous forces from the local model, thereby stabilizing the control loop.
The developed haptic data compression scheme reduced the number of packets sent across the network by 90%, while improving
the quality of the haptic feedback. 相似文献