全文获取类型
收费全文 | 698篇 |
免费 | 60篇 |
专业分类
电工技术 | 11篇 |
综合类 | 3篇 |
化学工业 | 255篇 |
金属工艺 | 7篇 |
机械仪表 | 6篇 |
建筑科学 | 35篇 |
矿业工程 | 2篇 |
能源动力 | 18篇 |
轻工业 | 150篇 |
水利工程 | 4篇 |
石油天然气 | 2篇 |
无线电 | 32篇 |
一般工业技术 | 115篇 |
冶金工业 | 45篇 |
原子能技术 | 3篇 |
自动化技术 | 70篇 |
出版年
2024年 | 1篇 |
2023年 | 8篇 |
2022年 | 39篇 |
2021年 | 60篇 |
2020年 | 21篇 |
2019年 | 22篇 |
2018年 | 26篇 |
2017年 | 24篇 |
2016年 | 32篇 |
2015年 | 30篇 |
2014年 | 35篇 |
2013年 | 40篇 |
2012年 | 51篇 |
2011年 | 63篇 |
2010年 | 33篇 |
2009年 | 29篇 |
2008年 | 42篇 |
2007年 | 33篇 |
2006年 | 31篇 |
2005年 | 27篇 |
2004年 | 18篇 |
2003年 | 20篇 |
2002年 | 20篇 |
2001年 | 4篇 |
2000年 | 5篇 |
1999年 | 5篇 |
1998年 | 7篇 |
1997年 | 4篇 |
1996年 | 7篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1974年 | 3篇 |
1973年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有758条查询结果,搜索用时 15 毫秒
61.
Akram El Hasni Stefan Pfirrmann Anett Kolander Erwin Yacoub-George Martin König Christof Landesberger Anja Voigt Gabi Grützner Uwe Schnakenberg 《Microfluidics and nanofluidics》2017,21(3):41
We present a new epoxy-based negative-tone dry film photoresist (DFR) for fabricating multilayer microfluidic devices using a lamination process combined with a standard photolithography technology. As proof-of-concept, a complex 3D-hydrodynamic focusing device was produced via a six-layer lamination process of 33 µm-thick DFR layers. The bonding strength of the new DFR was tested on silicon, glass, and titanium substrates, respectively. A maximum bonding strength of 37 MPa was obtained for the dry film photoresist laminated on glass. No leakage was found, and burst tests proved excellent robustness and sealing reliability of the microchannels. 相似文献
62.
Businesses in knowledge intensive industries must appropriately engage with their customers in order to produce goods and services that are desired and valued in the marketplace. Engagement with customers calls for exchanging information and knowledge with customers and fostering exchanges between customers. Recent developments in the area of information and communication technologies (ICTs) have radically increased the variety of opportunities for improving customer engagement. In this paper, we will examine the use of ICTs to build Business Customer Communities (BCCs) to help an organization foster knowledge exchanges between its professional and institutional customers. We define BCCs as groups of business customers, which are deliberately enabled by a firm and share a long-term need to exchange work related knowledge through online and offline interaction. The objectives of this study are (1) to describe BCCs and outline their attributes and features, and (2) to contribute to the understanding of challenges associated with the enabling of BCC formation and how firms can overcome these challenges. As such, a contribution is made to the discussion of knowing in practice in customer communities, which rely in large part on ICT. 相似文献
63.
Making it easier for older people to talk to smart homes: the effect of early help prompts 总被引:1,自引:0,他引:1
K. Maria Wolters Klaus-Peter Engelbrecht Florian Gödde Sebastian Möller Anja Naumann Robert Schleicher 《Universal Access in the Information Society》2010,9(4):311-325
It is well known that help prompts shape how users talk to spoken dialogue systems. This study investigated the effect of
help prompt placement on older users’ interaction with a smart home interface. In the dynamic help condition, help was only
given in response to system errors; in the inherent help condition, it was also given at the start of each task. Fifteen older
and sixteen younger users interacted with a smart home system using two different scenarios. Each scenario consisted of several
tasks. The linguistic style users employed to communicate with the system (interaction style) was measured using the ratio of commands to the overall utterance length (keyword ratio) and the percentage of content
words in the user’s utterance that could be understood by the system (shared vocabulary). While the timing of help prompts
did not affect the interaction style of younger users, it was early task-specific help supported older users in adapting their
interaction style to the system’s capabilities. Well-placed help prompts can significantly increase the usability of spoken
dialogue systems for older people. 相似文献
64.
Anja Wessels Stefan Fries Holger Horz Nicolai Scheele Wolfgang Effelsberg 《Computers in human behavior》2007
Among the severe instructional shortcomings of lectures is their lack of interactivity. To overcome these problems, the learning environment of the interactive lecture is introduced, in which students and lecturer interact by using mobile computers in a wireless network. In an experimental study, 44 students participated in interactive and in conventional lecture meetings. A quiz service that allowed question to be posted, students’ answers to be evaluated, and the results to be presented graphically, was implemented on mobile computers. The participants rated the interactive condition better, also reporting higher levels of attention, activity and perceived learning success for this condition. Objective measures indicated a slight but insignificant difference toward better learning results in the interactive condition. 相似文献
65.
66.
Anja Oskamp 《Artificial Intelligence and Law》1992,1(4):245-274
This paper presents a four layer model for working with legal knowledge in expert systems. It distinguishes five sources of knowledge. Four contain basic legal knowledge found in published and unpublished sources. The fifth consists of legal metaknowledge. In the model the four basic legal knowledge sources are placed at the lowest level. The metaknowledge is placed at levels above the other four knowledge sources. The assumption is that the knowledge is represented only once. The use of metaknowledge at various levels should make it possible to use the appropriate knowledge for the problem presented to the system. The knowledge has to be represented as closely to the original format as possible for this purpose. Suitable representation formalisms for the various types of knowledge in the five knowledge sources are discussed. It is not possible to indicate a best representation formalism for each knowledge source. 相似文献
67.
Damián Alvarez Paggi Anja Kranich Marcelo A. Martí Daniel H. Murgida 《Electrochimica acta》2009,54(22):4963-18098
In this paper we present a combined experimental and theoretical study of the heterogeneous electron transfer reaction of cytochrome c electrostatically adsorbed on metal electrodes coated with monolayers of 6-mercaptohexanoic acid. Molecular dynamics simulations and pathways calculations show that adsorption of the protein leads to a broad distribution of orientations and, thus, to a correspondingly broad distribution of electron transfer rate constants due to the orientation-dependence of the electronic coupling parameter. The adsorbed protein exhibits significant mobility and, therefore, the measured reaction rate is predicted to be a convolution of protein dynamics and tunnelling probabilities for each orientation. This prediction is confirmed by time-resolved surface enhanced resonance Raman which allows for the direct monitoring of protein (re-)orientation and electron transfer of the immobilised cytochrome c. The results provide a consistent explanation for the non-exponential distance-independence of electron transfer rates usually observed for proteins immobilized on electrodes. 相似文献
68.
Horst Biermann Ulrich Martin Christos G. Aneziris Anja Kolbe Angelika Müller Wolfgang Schärfl Mathias Herrmann 《Advanced Engineering Materials》2009,11(12):1000-1006
Novel composites on basis of austenitic stainless TRIP‐steel as matrix with reinforcements of Mg‐PSZ are presented. Compact rods were produced by cold isostatic pressing and sintering, square honeycomb samples by the ceramic extrusion technique. The samples are characterized by optical and scanning electron microscopy before and after deformation, showing the microstructure and the deformation‐ induced martensite formation. The mechanical properties of samples with 5 vol% zirconia are superior compared to zirconia‐free samples and composites with higher zirconia contents in terms of bending and compression tests. The honeycomb samples exhibit extraordinary high specific energy absorption in compression. 相似文献
69.
Investigations on insoluble dietary fibre (IDF) of wheat, rye, barley, oat, maize, rice and millet led to the identification
of several new dehydrodimers of ferulic acid (DFA). These compounds arise from 8–8′, 8–5′, 8–O–4′ and 5–5′ coupling. Esterified
phenolics were set free by mild alkali hydrolysis, total amounts of phenolics (ester- plus etherified) were determined by
alkali hydrolysis under pressure. Phenolic acids were analysed by gas chromatography – mass spectrometry (GC-MS) as their
trimethylsilyl (TMS) derivatives and by high performance liquid chromatography – diode array detection (HPLC-DAD). In esterified
form 8–8′aryl DFA and 5–5′ DFA dominate in most cereal IDF with, together, 45–60% of the DFA sum. More than 60% of total bound
DFA are involved in ether linkages. Highest amounts of esterified as well as etherified DFA are estimated in millet, followed
by maize. DFA contents of wheat, rye and barley are about two- to threefold lower than in millet but about twofold higher
than in oat or rice.
Received: 27 January 2000 相似文献
70.