全文获取类型
收费全文 | 5820篇 |
免费 | 321篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 76篇 |
综合类 | 13篇 |
化学工业 | 1494篇 |
金属工艺 | 138篇 |
机械仪表 | 115篇 |
建筑科学 | 402篇 |
矿业工程 | 29篇 |
能源动力 | 147篇 |
轻工业 | 451篇 |
水利工程 | 50篇 |
石油天然气 | 8篇 |
无线电 | 450篇 |
一般工业技术 | 1232篇 |
冶金工业 | 247篇 |
原子能技术 | 37篇 |
自动化技术 | 1258篇 |
出版年
2024年 | 11篇 |
2023年 | 102篇 |
2022年 | 140篇 |
2021年 | 230篇 |
2020年 | 150篇 |
2019年 | 128篇 |
2018年 | 190篇 |
2017年 | 165篇 |
2016年 | 248篇 |
2015年 | 242篇 |
2014年 | 301篇 |
2013年 | 400篇 |
2012年 | 380篇 |
2011年 | 462篇 |
2010年 | 356篇 |
2009年 | 340篇 |
2008年 | 341篇 |
2007年 | 317篇 |
2006年 | 240篇 |
2005年 | 211篇 |
2004年 | 159篇 |
2003年 | 149篇 |
2002年 | 126篇 |
2001年 | 81篇 |
2000年 | 78篇 |
1999年 | 66篇 |
1998年 | 75篇 |
1997年 | 45篇 |
1996年 | 49篇 |
1995年 | 57篇 |
1994年 | 34篇 |
1993年 | 33篇 |
1992年 | 29篇 |
1991年 | 20篇 |
1990年 | 18篇 |
1989年 | 18篇 |
1988年 | 15篇 |
1987年 | 13篇 |
1986年 | 8篇 |
1985年 | 5篇 |
1984年 | 23篇 |
1983年 | 9篇 |
1982年 | 9篇 |
1981年 | 7篇 |
1980年 | 7篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1976年 | 9篇 |
1975年 | 6篇 |
1974年 | 5篇 |
排序方式: 共有6147条查询结果,搜索用时 15 毫秒
1.
2.
3.
Torsten Bohlin Stefan F. Graebe 《International Journal of Adaptive Control and Signal Processing》1995,9(6):465-490
Grey box identification refers to the practice of identifying dynamical systems in model structures exploiting partial prior information. This contribution reviews a method for stochastic grey box identification and surveys experiences and lessons of applying it to a number of industrial processes. Issues to be addressed include advantages and costs of introducing stochastics into the model, the question of what contribution must be expected from the model designer as opposed to what can be formalized in computer algorithms, and an outlook on future plans to resolve present shortcomings. 相似文献
4.
5.
6.
Stefan Kasapis 《International Journal of Food Science & Technology》2002,37(4):403-413
The structural properties of mixtures of pectin, oxidized starch and glucose syrup were investigated using small deformation dynamic oscillation. In the absence of added calcium, preparations of low methoxy pectin with glucose syrup formed viscous solutions, which remained crystal-free at subzero temperatures. Samples of oxidized starch and glucose syrup, on the other hand, exhibited solid-like behaviour because of the crystalline nature of the amylose-like helices. Mixtures of the two polysaccharides with the co-solute clearly showed phase inversion from liquid to solid-like behaviour with increasing amounts of starch in the formulation. The transformation was reflected in the textural properties of samples, which varied from thick solutions to firm gels. The viscoelasticity of the system was modified further by the introduction of high methoxy pectin. Preparations of high methoxy pectin and glucose syrup formed rubbery gels whose amorphous nature underwent a glass transition during cooling. 相似文献
7.
Studies on the influence of anthracene coal extracts on the carbonization process of medium- and high-rank coals were undertaken. Extracts from flame coal (Int. Class. 900) and gas-coking coal (Int. Class. 632) were used as additives. The blends prepared from the examined coals and the extracts exhibited better coking properties than the parent coals. The addition of extract to the coals gave an increase in the microstrength of the resultant cokes. The effects of co-carbonization of coking coals with extracts were increases in the size of the optical texture as well as in the degree of structural ordering of cokes. In the co-carbonization of semicoking coal with addition of coal extracts, a reduction in the size of the anisotropic units and a decrease in the crystallite height of cokes were observed. No modification of the basic anisotropy of coke from anthracite by coal extract was observed. With increasing extract content in anthracite/extract blends there was an increase in the degree of structural ordering of co-carbonization products. Extract addition was unable to modify the behaviour of fusinite. Based on the results of investigation of the influence of coal extracts on the carbonization of different-rank coals, a division of coals according to the modification of the optical texture of coke is given. 相似文献
8.
9.
10.
In this paper, we present the findings from an extensive study of the use of virtual reality (VR) models in large construction projects. The study includes two parts: The first part presents a quantitative questionnaire designed to investigate how VR models are experienced and assessed by the workforce at a building site. The second part includes a qualitative field survey of how VR models can be applied and accepted by professionals in the design and planning process of a large pelletizing plant. Through mainly studying persons who had little or no experience with advanced information technology (IT), we hoped to reveal the attitudes of the average person working at a construction site rather than of an IT expert. In summary, the study shows that the VR models in both projects have been very useful and well accepted by the users. Today’s information flow is, from a general point of view, considered to be insufficient and the hypothesis is that using VR models in the construction process have the potential to minimize waste of resources and improve the final result. 相似文献