全文获取类型
收费全文 | 480篇 |
免费 | 15篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 77篇 |
金属工艺 | 22篇 |
机械仪表 | 14篇 |
建筑科学 | 7篇 |
矿业工程 | 2篇 |
能源动力 | 6篇 |
轻工业 | 127篇 |
水利工程 | 2篇 |
石油天然气 | 1篇 |
无线电 | 40篇 |
一般工业技术 | 79篇 |
冶金工业 | 68篇 |
原子能技术 | 3篇 |
自动化技术 | 43篇 |
出版年
2023年 | 5篇 |
2021年 | 7篇 |
2020年 | 5篇 |
2019年 | 5篇 |
2018年 | 6篇 |
2017年 | 3篇 |
2016年 | 5篇 |
2015年 | 7篇 |
2014年 | 14篇 |
2013年 | 19篇 |
2012年 | 14篇 |
2011年 | 20篇 |
2010年 | 18篇 |
2009年 | 10篇 |
2008年 | 17篇 |
2007年 | 25篇 |
2006年 | 22篇 |
2005年 | 17篇 |
2004年 | 18篇 |
2003年 | 14篇 |
2002年 | 5篇 |
2001年 | 4篇 |
1999年 | 4篇 |
1998年 | 21篇 |
1997年 | 13篇 |
1996年 | 10篇 |
1995年 | 12篇 |
1994年 | 7篇 |
1993年 | 19篇 |
1992年 | 19篇 |
1991年 | 14篇 |
1990年 | 11篇 |
1989年 | 8篇 |
1988年 | 5篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 5篇 |
1983年 | 3篇 |
1982年 | 7篇 |
1981年 | 4篇 |
1980年 | 6篇 |
1977年 | 6篇 |
1976年 | 12篇 |
1975年 | 5篇 |
1974年 | 6篇 |
1973年 | 5篇 |
1968年 | 2篇 |
1967年 | 3篇 |
1966年 | 2篇 |
1940年 | 2篇 |
排序方式: 共有495条查询结果,搜索用时 234 毫秒
1.
Marcus Weyd Christian Pflieger Andy Vogel Hannes Richter Volker Prehn Christiane Günther Frank Splittgerber Alessa Gäbler Daniel Kaulbars Patrick Bräutigam Marcus Franke Samira Lambertz Julian Schlechtweg Ingolf Voigt 《化学,工程师,技术》2021,93(9):1432-1439
Reducing micropollutant pollution of water bodies is an important objective of water management and an integral part of environmental policy. Ceramic nanofiltration membranes were developed as multichannel membranes of increased membrane area and rotating disk filters. The membranes developed show retention of over 80 % for PEG 400. The membranes are currently being tested for the separation of micropollutants from wastewater contaminated with pharmaceuticals. With the help of a downstream oxidative process, the trace substances remaining in the permeate are degraded. 相似文献
2.
Charles Weir Ingolf Becker James Noble Lynne Blair M. Angela Sasse Awais Rashid 《Software》2020,50(3):275-298
Though some software development teams are highly effective at delivering security, others either do not care or do not have access to security experts to teach them how. Unfortunately, these latter teams are still responsible for the security of the systems they build: systems that are ever more important to ever more people. We propose that a series of lightweight interventions, six hours of facilitated workshops delivered over three months, can improve a team's motivation to consider security and awareness of assurance techniques, changing its security culture even when no security experts are involved. The interventions were developed after an Appreciative Inquiry and Grounded Theory survey of security professionals to find out what approaches work best. We tested the interventions in a participatory action research field study where we delivered the workshops to three software development organizations and evaluated their effectiveness through interviews beforehand, immediately afterwards, and after twelve months. We found that the interventions can be effective with teams with limited or no security experience and that improvement is long-lasting. This approach and the learning points arising from the work here have the potential to be applied in many development teams, improving the security of software worldwide. 相似文献
3.
Yaneth Cardona Alexandra Torres Wolfgang Hoffmann Ingolf Lamprecht 《Food Analytical Methods》2018,11(4):1056-1067
Differential scanning calorimetry (DSC) was used to study the thermal behavior of Colombian honeys produced by the honey-bee Apis mellifera and by three species of stingless bees: Melipona fuscipes, Melipona favosa favosa, and Melipona compressipes. The honey samples were collected every 2 months over the course of year (August 2014 to August 2015). Up to four thermal transitions (trs1–trs4a, trs4b) were found in the honey samples: M. fuscipes (trs1–trs4a), M. favosa (trs1–trs4a, trs4b), M. compressipes (trs1, trs3, trs4a), and A. mellifera (trs1, trs3, trs4a). Statistical analyses showed significant differences in enthalpies of each transition between species; therefore, DSC analysis can be used as a finger-print to differentiate the honeys of species. 相似文献
4.
Suhaib Koji Baydoun Matthias Voigt Christopher Jelich Steffen Marburg 《International journal for numerical methods in engineering》2020,121(2):187-200
The solution of frequency dependent linear systems arising from the discretization of vibro-acoustic problems requires a significant computational effort in the case of rapidly varying responses. In this paper, we review the use of a greedy reduced basis scheme for the efficient solution in a frequency range. The reduced basis is spanned by responses of the system at certain frequencies that are chosen iteratively based on the response that is currently worst approximated in each step. The approximations at intermediate frequencies as well as the a posteriori estimations of associated errors are computed using a least squares solver. The proposed scheme is applied to the solution of an interior acoustic problem with boundary element method (BEM) and to the solution of coupled structural acoustic problems with finite element method and BEM. The computational times are compared to those of a conventional frequencywise strategy. The results illustrate the efficiency of the method. 相似文献
5.
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
6.
Claudia Voigt Tilo Zienert Pia Schubert Christos G. Aneziris Jana Hubálková 《Journal of the American Ceramic Society》2014,97(7):2046-2053
The aim of this study was to discuss the influence of different filter surface chemistries on the properties of foam filters. For reliable results, it is essential to ensure comparable structural properties (cell size and strut thickness) for all different surface chemistries (Al2O3, MgAl2O4, 3Al2O3·2SiO2, SiO2, and TiO2) possess the same structural properties (cell size and strut thickness). Filters made of 100% of the investigated materials and alumina skeletons coated with the investigated materials were prepared. The coated alumina samples were sintered in one and two steps. The processing route with two sintering steps resulted in improved mechanical properties and comparable shrinkage and strut thickness. The 100% bulk foams possessed different pore sizes due to the differences of the material shrinkage. In this study, a comparison of the experimental investigated properties of the ceramic foam filters and the theoretically calculated values for foam materials derived from the bulk material properties is established. 相似文献
7.
Comparative Investigation of Hydrogen Embrittlement of Palladium Deposits from Ionic Liquid and Aqueous Electrolyte 下载免费PDF全文
8.
Baclofen facilitates the extinction of methamphetamine-induced conditioned place preference in rats.
The powerful, long-lasting association between the rewarding effects of a drug and contextual cues associated with drug administration can be studied using conditioned place preference (CPP). The GABAB receptor agonist baclofen facilitates the extinction of morphine-induced CPP in mice. The current study extended this work by determining if baclofen could enhance the extinction of methamphetamine (Meth) CPP. CPP was established using a six-day conditioning protocol wherein Meth-pairings were alternated with saline-pairings. Rats were subsequently administered baclofen (2 mg/kg i.p. or vehicle) immediately after each daily forced extinction session, which consisted of a saline injection immediately prior to being placed into the previously Meth- or saline-paired chamber. One extinction training cycle, consisted of six once-daily forced extinction sessions, mimicking the alternating procedure established during conditioning, followed by a test for preference (Ext test). CPP persisted for at least four extinction cycles in vehicle-treated rats. In contrast, CPP was inhibited following a single extinction training cycle. These data indicate that Meth-induced CPP was resistant to extinction, but extinction training was rendered effective when the training was combined with baclofen. These findings converge with the prior demonstration of baclofen facilitating the extinction of morphine-induced CPP indicating that GABAB receptor actions are independent of the primary (unconditioned) stimulus (i.e., the opiate or the stimulant) and likely reflect mechanisms engaged by extinction learning processes per se. Thus, baclofen administered in conjunction with extinction training may be of value for addiction therapy regardless of the class of drug being abused. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
9.
R. C. Voigt 《International Journal of Cast Metals Research》2013,26(2):71-93
Recent research on austempered ductile irons (ADI) has been reviewed. The physical metallurgy of the austempering reaction and the important effects of alloying elements are discussed, along with an analysis of research results from the perspectives of ADI foundry and heat treatment process control and quality assurance. Both the existing database of ADI mechanical properties and progress made toward the specification of various ADI grades worldwide have been summarised. Although many fundamental questions remain regarding microstructure/property/processing relationships for the new and metallurgically complex family of ADI materials, foundry processing and heat treatment guidelines have been established for the successful production of ADI. Casting quality requirements are high due to the demanding combination of strength and toughness desired for ADI and to ensure consistent heat-treatment response during austempering. 相似文献
10.
Tilman Voigt Benoît Zuber Gerlinde Gawatz Gudrun Herrmann 《Microscopy research and technique》2013,76(7):679-686
In the long run, the widespread use of slide scanners by pathologists requires an adaptation of teaching methods in histology and cytology in order to target these new possibilities of image processing and presentation via the internet. Accordingly, we were looking for a tool with the possibility to teach microscopic anatomy, histology, and cytology of tissue samples which would be able to combine image data from light and electron microscopes independently of microscope suppliers. With the example of a section through the villus of jejunum, we describe here how to process image data from light and electron microscopes in order to get one image‐stack which allows a correlation of structures from the microscopic anatomic to the cytological level. With commercially available image‐presentation software that we adapted to our needs, we present here a platform which allows for the presentation of this new but also of older material independently of microscope suppliers. Microsc. Res. Tech. 76:679–686, 2013. © 2013 Wiley Periodicals, Inc. 相似文献