全文获取类型
收费全文 | 2360篇 |
免费 | 115篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 17篇 |
综合类 | 4篇 |
化学工业 | 534篇 |
金属工艺 | 40篇 |
机械仪表 | 53篇 |
建筑科学 | 215篇 |
矿业工程 | 1篇 |
能源动力 | 114篇 |
轻工业 | 263篇 |
水利工程 | 40篇 |
石油天然气 | 5篇 |
无线电 | 149篇 |
一般工业技术 | 437篇 |
冶金工业 | 121篇 |
原子能技术 | 18篇 |
自动化技术 | 465篇 |
出版年
2023年 | 26篇 |
2022年 | 50篇 |
2021年 | 55篇 |
2020年 | 43篇 |
2019年 | 52篇 |
2018年 | 63篇 |
2017年 | 54篇 |
2016年 | 67篇 |
2015年 | 61篇 |
2014年 | 89篇 |
2013年 | 169篇 |
2012年 | 142篇 |
2011年 | 158篇 |
2010年 | 137篇 |
2009年 | 117篇 |
2008年 | 145篇 |
2007年 | 123篇 |
2006年 | 114篇 |
2005年 | 104篇 |
2004年 | 94篇 |
2003年 | 73篇 |
2002年 | 79篇 |
2001年 | 34篇 |
2000年 | 31篇 |
1999年 | 34篇 |
1998年 | 38篇 |
1997年 | 25篇 |
1996年 | 25篇 |
1995年 | 18篇 |
1994年 | 23篇 |
1993年 | 23篇 |
1992年 | 15篇 |
1991年 | 8篇 |
1990年 | 8篇 |
1989年 | 11篇 |
1988年 | 9篇 |
1987年 | 8篇 |
1984年 | 9篇 |
1983年 | 6篇 |
1982年 | 7篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1978年 | 7篇 |
1943年 | 16篇 |
1942年 | 12篇 |
1941年 | 8篇 |
1940年 | 8篇 |
1939年 | 7篇 |
1938年 | 5篇 |
1937年 | 5篇 |
排序方式: 共有2476条查询结果,搜索用时 15 毫秒
41.
Håvard Fjær Grip Author Vitae Lars Imsland Author Vitae Author Vitae Thor I. Fossen Author Vitae Jens C. Kalkkuhl Author Vitae Author Vitae 《Automatica》2008,44(3):611-622
A nonlinear observer for estimation of the longitudinal velocity, lateral velocity, and yaw rate of a vehicle, designed for the purpose of vehicle side-slip estimation, is modified and extended in order to work for different road surface conditions. The observer relies on a road-tire friction model and is therefore sensitive to changes in the adhesion characteristics of the road surface. The friction model is parametrized with a single friction parameter, and an update law is designed. The adaptive observer is proven to be uniformly globally asymptotically stable and uniformly locally exponentially stable under a persistency-of-excitation condition and a set of technical assumptions, using results related to Matrosov's theorem. The observer is tested on recorded data from two test vehicles and shows good results on a range of road surfaces. 相似文献
42.
The unique properties of 2D-materials like graphene are exploited in various electronic devices. In sensor applications, graphene shows a very high sensitivity, but only a low specificity. This shortcoming can be mastered by using heterostructures, where graphene is combined with materials exhibiting high analyte selectivities. Herein, this study demonstrates the precise deposition of nanoporous metal-organic frameworks (MOFs) on graphene, yielding bilayers with excellent specificity while the sensitivity remains large. The key for the successful layer-by-layer deposition of the MOF films (SURMOFs) is the use of planar polyaromatic anchors. Then, the MOF pores are loaded with ionic liquid (IL). For functioning sensor devices, the IL@MOF films are grown on graphene field-effect transistors (GFETs). Adding a top-gate electrode yields an ion-gated GFET. Analysis of the transistor characteristics reveals a clear Dirac point at low gate voltages, good on-off ratios, and decent charge mobilities and densities in the graphene channel. The GFET-sensor reveals a strong and selective response. Compared to other ion-gated-FET devices, the IL@MOF material is relatively hard, allowing the manufacturing of ultrathin devices. The new MOF-anchoring strategy offers a novel approach generally applicable for the functionalization of 2D-materials, where MOF/2D-material hetero-bilayers carry a huge potential for a wide variety of applications. 相似文献
43.
Junying Min Patrick Seim Denis Störkle Lars Thyssen Bernd Kuhlenkötter 《International Journal of Material Forming》2017,10(5):729-739
A thermal model was built to account for the effects of geometrical parameters of sheet specimen, process parameters and material parameters on the temperature increase of the sheet specimen in Electricity-Assisted Incremental Sheet Forming (EISF). In the EISF, the local area of sheet specimen contacting with a forming tool is heated by direct current, which flows through the forming tool to the sheet specimen. EISF experiments of two high strength steel sheets were carried out to validate the thermal model. The thermal model can be integrated into the control program of EISF system to achieve more accurate temperature control. 相似文献
44.
45.
Jens Hauslage Medea Abbrecht Lars Hanke Ruth Hemmersbach Claudia Koch Wolfgang Hanke Florian P. M. Kohn 《Microgravity science and technology》2016,28(6):633-638
All life on earth has been established under conditions of stable gravity of 1g. Nevertheless, in numerous experiments the direct gravity dependence of biological processes has been shown on all levels of organization, from single molecules to humans. To study the effects especially of microgravity on biological systems, a variety of platforms are available, from drop towers to the ISS. Due to the costs of these platforms and their limited availability, as an alternative, numerous simulators have been developed for so called “simulated” microgravity. A classical systems is a clinostat, basically rotating a sample around one axis, and by integration of the gravity vector for 360° arguing that thus the effects of gravity are depleted. Indeed, a variety of studies has shown that taking out the direction of gravity from a biological system often results in consequences similar to the exposure of the system to real microgravity. Nevertheless, the opposite has been shown, too, and as a consequence the relevance of clinostats in microgravity research is still under discussion. To get some more insight into this problem we have constructed a small fluorescence clinostat and have studied the effects of clinorotation on the cytosolic calcium concentration of neuroglioma cells. The results have been compared to experiments with identical cells in real microgravity, utilizing parabolic flight missions. Our results show that in case of a cell suspension used in a small florescence clinostat within a tube diameter of 2mm, the effects of clinorotation are comparable to those under real microgravity, both showing a significant increase in intracellular calcium concentration. 相似文献
46.
47.
Oxidative Stress Imaging: Visualizing Oxidative Cellular Stress Induced by Nanoparticles in the Subcytotoxic Range Using Fluorescence Lifetime Imaging (Small 23/2018)
下载免费PDF全文
![点击此处可从《Small (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
48.
Feature Tracking with Automatic Selection of Spatial Scales 总被引:1,自引:0,他引:1
49.
Lars Mönch John W. Fowler Stéphane Dauzère-Pérès Scott J. Mason Oliver Rose 《Journal of Scheduling》2011,14(6):583-599
In this paper, we discuss scheduling problems in semiconductor manufacturing. Starting from describing the manufacturing process,
we identify typical scheduling problems found in semiconductor manufacturing systems. We describe batch scheduling problems,
parallel machine scheduling problems, job shop scheduling problems, scheduling problems with auxiliary resources, multiple
orders per job scheduling problems, and scheduling problems related to cluster tools. We also present important solution techniques
that are used to solve these scheduling problems by means of specific examples, and report on known implementations. Finally,
we summarize some of the challenges in scheduling semiconductor manufacturing operations. 相似文献
50.
Increasingly, customer companies hire external information technology (IT) consultants, often on a special project basis. These consultants are employees of professional service firms, although they receive their assignments from the hiring companies, report to them, and are supervised by them. Using semistructured interviews with 12 IT consultants in Sweden, we examine the factors that influence their work motivation, including the effect of this dual allegiance—to the service firm and to the customer company. The data indicate that the primary motivators are the variety in tasks and the opportunity to influence and/or manage an entire project. Neither monetary incentives nor the consultancy firm norms are strong motivators. A factor that affects work behavior and motivation is the subordinate identity that IT consultants must assume with their powerful clients. The article concludes with practical suggestions for managers who seek to understand what motivates employees who work at a distance, under external control. © 2011 Wiley Periodicals, Inc. 相似文献