全文获取类型
收费全文 | 334篇 |
免费 | 23篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 92篇 |
金属工艺 | 15篇 |
机械仪表 | 7篇 |
建筑科学 | 21篇 |
矿业工程 | 1篇 |
能源动力 | 23篇 |
轻工业 | 23篇 |
水利工程 | 3篇 |
无线电 | 22篇 |
一般工业技术 | 69篇 |
冶金工业 | 13篇 |
原子能技术 | 3篇 |
自动化技术 | 60篇 |
出版年
2023年 | 5篇 |
2022年 | 4篇 |
2021年 | 11篇 |
2020年 | 10篇 |
2019年 | 5篇 |
2018年 | 13篇 |
2017年 | 5篇 |
2016年 | 10篇 |
2015年 | 11篇 |
2014年 | 20篇 |
2013年 | 20篇 |
2012年 | 21篇 |
2011年 | 18篇 |
2010年 | 20篇 |
2009年 | 18篇 |
2008年 | 20篇 |
2007年 | 19篇 |
2006年 | 12篇 |
2005年 | 15篇 |
2004年 | 11篇 |
2003年 | 6篇 |
2002年 | 8篇 |
2001年 | 9篇 |
1999年 | 5篇 |
1998年 | 7篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有357条查询结果,搜索用时 31 毫秒
21.
Junhua Zhao Shijo Nagao Gregory M Odegard Zhiliang Zhang Helge Kristiansen Jianying He 《Nanoscale research letters》2013,8(1):541
Anisotropic conductive adhesives (ACAs) are promising materials used for producing ultra-thin liquid-crystal displays. Because the mechanical response of polymer particles can have a significant impact in the performance of ACAs, understanding of this apparent size effect is of fundamental importance in the electronics industry. The objective of this research is to use a coarse-grained molecular dynamics model to verify and gain physical insight into the observed size dependence effect in polymer particles. In agreement with experimental studies, the results of this study clearly indicate that there is a strong size effect in spherical polymer particles with diameters approaching the nanometer length scale. The results of the simulations also clearly indicate that the source for the increases in modulus is the increase in relative surface energy for decreasing particle sizes. Finally, the actual contact conditions at the surface of the polymer nanoparticles are shown to be similar to those predicted using Hertz and perfectly plastic contact theory. As ACA thicknesses are reduced in response to reductions in polymer particle size, it is expected that the overall compressive stiffness of the ACA will increase, thus influencing the manufacturing process. 相似文献
22.
The production of high performance metal parts requires a well balanced sequence of operations and can usually technologically not be achieved in a single process. This issue leads to complex process chains on the shop floor and the requirement to split single processes into multistage processes in hard-finishing operations. In both cases, the objective for the process planning is to achieve not only a local optimum for the individual processes but rather an overall optimum for the complete sequence. In order to reach the overall optimum, the process planner needs to integrate the effects between the processes into consideration. These effects which are referred to as cross-process interdependencies lead to balanced settings of process parameters and results in a much more effective operation of the sequence. In this paper, a novel approach dealing with the integration of cross-process interdependencies in the hard-finishing process of multistage grinding is introduced. It is based on an a-priori multicriteria dimensioning procedure which allows the integration of cross-process interdependencies and is implemented in software programmed in JAVA. A multistage plunge grinding process for crankshaft journals is used for evaluation of the results predicted by a developed software prototype. 相似文献
23.
Chest compression is a vital part of cardiopulmonary resuscitation (CPR). This paper demonstrates how the compression depth can be estimated using the principles of inertia navigation. The proposed method uses accelerometer sensors, one placed on the patient's chest, the other beside the patient. The acceleration-to-position conversion is performed using discrete-time digital signal processing (DSP). Instability problems due to integration are combated using a set of boundary conditions. The proposed algorithm is tested on a mannequin in harsh environments, where the patient is exposed to external forces as in a boat or car, as well as improper sensor/patient alignment. The overall performance is an estimation depth error of 4.3 mm in these environments, which is reduced to 1.6 mm in a regular, flat-floor controlled environment. 相似文献
24.
25.
Gunther?HeidemannEmail author Robert?Rae Holger?Bekel Ingo?Bax Helge?Ritter 《Machine Vision and Applications》2004,16(1):64-73
We present a vision system for human-machine interaction based on a small wearable camera mounted on glasses. The camera views the area in front of the user, especially the hands. To evaluate hand movements for pointing gestures and to recognise object references, an approach to integrating bottom-up generated feature maps and top-down propagated recognition results is introduced. Modules for context-free focus of attention work in parallel with the hand gesture recognition. In contrast to other approaches, the fusion of the two branches is on the sub-symbolic level. This method facilitates both the integration of different modalities and the generation of auditory feedback.Published online: 5 October 2004Robert Rae: Now at PerFact Innovation, Lampingstr. 8, 33615 Bielefeld, Germany 相似文献
26.
BCI Competition 2003--Data set IIb: support vector machines for the P300 speller paradigm 总被引:2,自引:0,他引:2
Kaper M Meinicke P Grossekathoefer U Lingner T Ritter H 《IEEE transactions on bio-medical engineering》2004,51(6):1073-1076
We propose an approach to analyze data from the P300 speller paradigm using the machine-learning technique support vector machines. In a conservative classification scheme, we found the correct solution after five repetitions. While the classification within the competition is designed for offline analysis, our approach is also well-suited for a real-world online solution: It is fast, requires only 10 electrode positions and demands only a small amount of preprocessing. 相似文献
27.
Helge Szwerinski 《Theoretical computer science》1982,19(3):305-320
A time-optimal solution to the firing-squad-synchronization-problem of n-dimensional rectangles with the general at an arbitrary position is presented. The solution uses one-dimensional time-optimal fssp algorithms which have a symmetrical transition function and use as few states as the best known non-symmetrical transition functions. The n-dimensional case is demonstrated for n = 2, and the straightforward generalization to larger n is outlined. 相似文献
28.
Jakob PM Wang T Schultz G Hebestreit H Hebestreit A Elfeber M Hahn D Haase A 《Magma (New York, N.Y.)》2002,15(1-3):10-17
The unique characteristics of the human lung arising from low proton density and multiple air-tissue interfaces of the alveoli
cause difficulty in1H lung magnetic resonance imaging. In addition, the dominating signal from sources such as the thoracic muscle and subcutaneous
fat hampers the visualization of the lung parenchyma. In this contribution, an efficient tissue suppression technique is presented
which allows one to significantly enhance lung parenchyma visibility. A short inversion time inversion recovery (STIR) experiment
combined with a magnetization transfer (MT) experiment was used for magnetization preparation in order to suppress the signal
from muscle. A half-Fourier single-shot turbo spin-echo sequence was used as acquisition module. This approach was used to
perform lung anatomical imaging in eight healthy human subjects and five patients withcystic fibrosis. The results obtained demonstrate that with MT-STIR approach high quality human lung images can be obtained and that this
approach has the potential for the evaluation of lung pathologies. 相似文献
29.
Bayesian networks in reliability 总被引:7,自引:1,他引:7
Over the last decade, Bayesian networks (BNs) have become a popular tool for modelling many kinds of statistical problems. We have also seen a growing interest for using BNs in the reliability analysis community. In this paper we will discuss the properties of the modelling framework that make BNs particularly well suited for reliability applications, and point to ongoing research that is relevant for practitioners in reliability. 相似文献
30.
Access control mechanisms protect critical resources of systems from unauthorized access. In a policy-based management approach, administrators define user privileges as rules that determine the conditions and the extent of users’ access rights. As rules become more complex, analytical skills are required to identify conflicts and interactions within the rules that comprise a system policy—especially when rules are stateful and depend on event histories. Without adequate tool support such an analysis is error-prone and expensive. In consequence, many policy specifications are inconsistent or conflicting that render the system insecure. The security of the system, however, does not only depend on the correct specification of the security policy, but in a large part also on the correct interpretation of those rules by the system’s enforcement mechanism. In this paper, we show how policy rules can be formalized in Fusion Logic, a temporal logic for the specification of behavior of systems. A symbolic decision procedure for Fusion Logic based on Binary Decision Diagrams (BDDs) is provided and we introduce a novel technique for the construction of enforcement mechanisms of access control policy rules that uses a BDD encoded enforcement automaton based on input traces which reflect state changes in the system. We provide examples of verification of policy rules, such as absence of conflicts, and dynamic separation of duty and of the enforcement of policies using our prototype implementation (FLCheck) for which we detail the underlying theory. 相似文献