全文获取类型
收费全文 | 6272篇 |
免费 | 385篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 119篇 |
综合类 | 4篇 |
化学工业 | 1806篇 |
金属工艺 | 186篇 |
机械仪表 | 174篇 |
建筑科学 | 189篇 |
矿业工程 | 21篇 |
能源动力 | 229篇 |
轻工业 | 919篇 |
水利工程 | 39篇 |
石油天然气 | 22篇 |
无线电 | 347篇 |
一般工业技术 | 1455篇 |
冶金工业 | 103篇 |
原子能技术 | 57篇 |
自动化技术 | 991篇 |
出版年
2023年 | 73篇 |
2022年 | 174篇 |
2021年 | 266篇 |
2020年 | 160篇 |
2019年 | 175篇 |
2018年 | 269篇 |
2017年 | 262篇 |
2016年 | 297篇 |
2015年 | 226篇 |
2014年 | 319篇 |
2013年 | 664篇 |
2012年 | 395篇 |
2011年 | 471篇 |
2010年 | 416篇 |
2009年 | 297篇 |
2008年 | 250篇 |
2007年 | 210篇 |
2006年 | 147篇 |
2005年 | 77篇 |
2004年 | 66篇 |
2003年 | 81篇 |
2002年 | 76篇 |
2001年 | 58篇 |
2000年 | 70篇 |
1999年 | 49篇 |
1998年 | 42篇 |
1997年 | 32篇 |
1996年 | 43篇 |
1995年 | 42篇 |
1994年 | 44篇 |
1993年 | 47篇 |
1992年 | 41篇 |
1991年 | 30篇 |
1990年 | 30篇 |
1989年 | 31篇 |
1988年 | 23篇 |
1985年 | 48篇 |
1984年 | 56篇 |
1983年 | 46篇 |
1982年 | 45篇 |
1981年 | 67篇 |
1980年 | 55篇 |
1979年 | 46篇 |
1978年 | 42篇 |
1977年 | 36篇 |
1976年 | 46篇 |
1975年 | 34篇 |
1974年 | 22篇 |
1973年 | 33篇 |
1972年 | 18篇 |
排序方式: 共有6661条查询结果,搜索用时 15 毫秒
91.
G. S. Vuković N. Lj. Perović K. D. Maglić 《International Journal of Thermophysics》1996,17(5):1057-1067
This paper describes improvements introduced in data reduction in direct heating pulse specific heat experiments. In calculations of specific heat, it is necessary to calculate the first derivative of the recorded temperature data as a function of time. The error induced by different numerical differentiation techniques can represent a significant part of the overall measurement error. Thus, different digital filtering techniques, differentiation, and smoothing algorithms were applied and tested to examine their influence on the minimization of errors induced by noise, which is unavoidable in measured signals. A minimum square error criterion was applied in designing digital filters, with arbitrary prescribed magnitude characteristics. Attention was paid to applications when one or more structural phase transitions in the specimen material occur within the temperature range covered by the experiment. The cases where the frequency spectrum of induced noise overlaps with the spectrum of temperature transient signals originating from phase transitions were analyzed in detail. The effectiveness of the methods of extracting the final specific heat data from a noisy signal using different digital filtering techniques is demonstrated.Paper presented at the Fourth International Workshop on Subsecond Thermophysics, June 27–29, 1995, Köln, Germany. 相似文献
92.
In this paper we study a class of CQ Horn functions introduced in Boros et al. (Ann Math Artif Intell 57(3–4):249–291, 2010). We prove that given a CQ Horn function f, the maximal number of pairwise disjoint essential sets of implicates of f equals the minimum number of clauses in a CNF representing f. In other words, we prove that the maximum number of pairwise disjoint essential sets of implicates of f constitutes a tight lower bound on the size (the number of clauses) of any CNF representation of f. 相似文献
93.
When programmers need to modify third‐party applications, they frequently do not have access to their source code. In such cases, DLL injection and API hooking are techniques that can be used to modify applications without intervening into their source code. The commonly used varieties of injection and hooking approaches have many practical limitations: they are inconvenient for a programmer to implement, do not work reliably in conjunction with all applications and with certain low‐level machine instructions. In this paper we present two novel approaches to DLL injection and API hooking, which we call Debugger‐aided DLL injection and Single Instruction Hooking. Our approaches overcome the limitations of the state‐of‐the art approaches. Despite incurring greater execution times, our approach allows extending of the applications in situations where the comparable approaches fail. As such, it has a notable practical value for beneficial practical applications of injection and hooking approaches, which are present in malware detection programs and computer security tools. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
94.
95.
Petra Punčochářová-Pořízková Jiří Fürst Jaromír Horáček Karel Kozel 《Mathematics and computers in simulation》2010
This study deals with a numerical solution of a 2D unsteady flow of a compressible viscous fluid in a channel for low inlet airflow velocity. The unsteadiness of the flow is caused by a prescribed periodic motion of a part of the channel wall with large amplitudes, nearly closing the channel during oscillations. The channel is a simplified model of the glottal space in the human vocal tract and the flow can represent a model of airflow coming from the trachea, through the glottal region with periodically vibrating vocal folds, and to the human vocal tract. 相似文献
96.
97.
Urban environments possess many regularities which can be efficiently exploited for 3D dense reconstruction from multiple
widely separated views. We present an approach utilizing properties of piecewise planarity and restricted number of plane
orientations to suppress reconstruction and matching ambiguities causing failures of standard dense stereo methods. We formulate
the problem of the 3D reconstruction in MRF framework built on an image pre-segmented into superpixels. Using this representation,
we propose novel photometric and superpixel boundary consistency terms explicitly derived from superpixels and show that they
overcome many difficulties of standard pixel-based formulations and handle favorably problematic scenarios containing many
repetitive structures and no or low textured regions. We demonstrate our approach on several wide-baseline scenes demonstrating
superior performance compared to previously proposed methods. 相似文献
98.
99.
100.
N. Lilić I. Obradović A. Cvjetić 《Engineering Applications of Artificial Intelligence》2010,23(4):453-462
Analysis of safety in surface coal mines represents a very complex process. Published studies on mine safety analysis are usually based on research related to accidents statistics and hazard identification with risk assessment within the mining industry. Discussion in this paper is focused on the application of AI methods in the analysis of safety in mining environment. Complexity of the subject matter requires a high level of expert knowledge and great experience. The solution was found in the creation of a hybrid system PROTECTOR, whose knowledge base represents a formalization of the expert knowledge in the mine safety field. The main goal of the system is the estimation of mining environment as one of the significant components of general safety state in a mine. This global goal is subdivided into a hierarchical structure of subgoals where each subgoal can be viewed as the estimation of a set of parameters (gas, dust, climate, noise, vibration, illumination, geotechnical hazard) which determine the general mine safety state and category of hazard in mining environment. Both the hybrid nature of the system and the possibilities it offers are illustrated through a case study using field data related to an existing Serbian surface coal mine. 相似文献