全文获取类型
收费全文 | 449篇 |
免费 | 32篇 |
专业分类
电工技术 | 2篇 |
综合类 | 1篇 |
化学工业 | 139篇 |
金属工艺 | 4篇 |
机械仪表 | 7篇 |
建筑科学 | 19篇 |
能源动力 | 3篇 |
轻工业 | 74篇 |
无线电 | 36篇 |
一般工业技术 | 134篇 |
冶金工业 | 30篇 |
自动化技术 | 32篇 |
出版年
2023年 | 6篇 |
2022年 | 19篇 |
2021年 | 15篇 |
2020年 | 8篇 |
2019年 | 7篇 |
2018年 | 10篇 |
2017年 | 11篇 |
2016年 | 11篇 |
2015年 | 15篇 |
2014年 | 14篇 |
2013年 | 28篇 |
2012年 | 31篇 |
2011年 | 43篇 |
2010年 | 28篇 |
2009年 | 18篇 |
2008年 | 26篇 |
2007年 | 24篇 |
2006年 | 20篇 |
2005年 | 23篇 |
2004年 | 11篇 |
2003年 | 10篇 |
2002年 | 10篇 |
2001年 | 8篇 |
2000年 | 8篇 |
1999年 | 2篇 |
1998年 | 6篇 |
1997年 | 1篇 |
1996年 | 5篇 |
1995年 | 4篇 |
1994年 | 6篇 |
1993年 | 12篇 |
1992年 | 4篇 |
1991年 | 7篇 |
1990年 | 8篇 |
1989年 | 6篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1983年 | 4篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1977年 | 3篇 |
1976年 | 1篇 |
排序方式: 共有481条查询结果,搜索用时 31 毫秒
11.
In the academic debate on infrastructures in the Global South, there is a broad consensus that (post)colonial legacies present a major challenge for a transition towards more inclusive, sustainable and adapted modes of providing services. Yet, relatively little is known about the emergence and evolution of infrastructures in former colonies. Until a decade ago, most historical studies followed Daniel Headrick’s (1981) “tools of empire” thesis, painting—with broad brush strokes—a picture of infrastructures as instruments for advancing the colonial project of exploitation and subordination of non-European peoples and environments. This paper explores new research perspectives beyond this straightforward, ‘diffusionist’ perspective on technology transfer. In order to do so, it presents and discusses more recent studies which focus on interactive transfer processes as well as mechanisms of appropriation, and which increasingly combine approaches from imperial history, environmental history, and history of technology.There is much to gain from unpacking the changing motives and ideologies behind technology transfer; tracing the often contested and negotiated flows of ideas, technologies and knowledge within multilayered global networks; investigating the manifold ways in which infrastructures reflected and (re)produced colonial spaces and identities; critically reflecting on the utility of large (socio)technical systems (LTS) for the Global South; and approaching infrastructures in the (post)colonial world through entangled histories of technology and the environment. Following David Arnold’s (2005) plea for a “more interactive, culturally-nuanced, multi-sited debate” on technology in the non-Western world, the paper offers fresh insights for a broader debate about how infrastructures work within specific parameters of time, place and culture. 相似文献
12.
Ute C. Herzfeld Bruce F. Wallin Carlton J. LeuschenJoel Plummer 《Computers & Geosciences》2011,37(11):1793-1801
The objective of this paper is to derive an algorithm for preserving important subscale morphologic characteristics at grids of lower-resolution, in particular for linear features such as canyons and ridge lines. The development of such an algorithm is necessitated by applications that require reduced spatial resolution, as is common in cartographic generalization, GIS applications, and geophysical modeling. Since any algorithm that results in weighted averages, including optimum interpolation and ordinary kriging, cannot reproduce correct depths, a new algorithm is designed based on principles of mathematical morphology. The algorithm described here is applied to derive a subglacial bed of the Greenland Ice Sheet that includes the trough of Jakobshavn Isbræ as a continuous canyon at correct depth in a low-resolution (5-km) digital elevation model (DEM). Data from recent airborne radar measurements of the elevation of the subglacial bed as part of the CReSIS project are utilized. The morphologic algorithm is designed with geophysical ice-sheet modeling in mind, in the following context. Currently occurring changes in the Earth's climate and the cryosphere cause changes in sea level, and the societal relevance of these natural processes motivates estimation of maximal sea-level rise in the medium-term future. The fast-moving outlet glaciers are more sensitive to climatic change than other parts of the Greenland ice sheet. Jakobshavn Isbrae, the fastest-moving ice stream in Greenland, follows a subglacial geologic trough. Since the existence of the trough causes the acceleration of the slow-moving inland ice in the Jakobshavn region and the formation of the ice stream, correct representation of the trough in a DEM is essential to model changes in the dynamics of the ice sheet and resultant sea-level predictions, even if current ice-sheet models can typically be run only at 5-km resolution. The DEM resultant from this study helps to bridge the conceptual gap between data analysis and geophysical modeling approaches. It is available as SeaRISE Greenland bed data set dev1.2 at http://websrv.cs.umt.edu/isis/index.php/SeaRISE_Assessment. 相似文献
13.
Bayen Ute J.; Erdfelder Edgar; Bearden J. Neil; Lozito Jeffrey P. 《Canadian Metallurgical Quarterly》2006,32(5):1003
Hindsight bias is the phenomenon that after people are presented with the correct answer to a question, their judgment regarding their own past answer to this question is biased toward the correct answer. In three experiments, younger and older adults gave numerical responses to general-knowledge questions and later attempted to recall their responses. For some questions, the correct answer was provided during recall (Experiment 1) or before recall (Experiments 2 and 3). Multinomial model-based analyses show age differences in both recollection bias and reconstruction bias when the correct judgment was in working memory during the recall phase. The authors discuss implications for theories of cognitive aging and theories of hindsight bias. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
14.
Kunzmann Ute; Kupperbusch Cenita S.; Levenson Robert W. 《Canadian Metallurgical Quarterly》2005,20(1):144
This study investigated age differences in the ability to suppress and amplify expressive behavior during emotional arousal. Young and old participants viewed 3 film clips about medical procedures while their behavioral, autonomic, and subjective responses were recorded. Half of the participants viewed all 3 films without additional instructions; the other half was asked to suppress and amplify their behavioral expression during the 2nd and 3rd films. Except for heart rate, suppression and amplification produced similar patterns of autonomic activation. Neither suppression nor amplification had effects on self-reported emotion. There were no age differences in the ability to suppress or amplify emotional expression or in their physiological or subjective consequences. Considering that older people's unregulated reactivity was lower than that of young adults, suppression may have been easier and amplification more difficult for older adults. Voluntary emotion regulation might be one domain of human performance that is spared from age-related losses. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
15.
16.
The radical polymerization of N‐isopropylacrylamide was carried out in toluene at low temperatures in the presence of silyl alcohols, such as triethylsilanol. Poly(N‐isopropylacrylamide) with a racemo dyad content of 75% was obtained at ? 80 °C with a 4:1 triethylsilanol to monomer ratio loading. NMR analysis suggests that the mechanism for syndiotactic induction, in the presence of silyl alcohols, may be similar to that observed with alkyl alcohols. In this case, a 1:2 complex formation, via hydrogen bonding interactions, leads to the induction of syndiotactic specificity. Copyright © 2012 Society of Chemical Industry 相似文献
17.
Matthias Schulz Ute Pippardt Lutz Kiesel Katrin Ritter Ralf Kriegel 《American Institute of Chemical Engineers》2012,58(10):3195-3202
Ba0.5Sr0.5Co0.8Fe0.2O3‐δ tubes, capillaries, capillary modules, and asymmetric membranes were prepared and tested for oxygen permeation in a dead‐end vacuum operation mode at temperatures up to 850°C. The capillary module was built up by reactive air brazing using seven capillaries and a supply tube. Two machined discs were used as an end cap and as a connector plate. The oxygen permeation behaves according to Wagner at small driving forces, but significant negative deviations were observed for asymmetric membranes and single capillaries at higher ones. This is caused by pressure drops at the vacuum side for single capillaries. The highest oxygen flux was revealed for the capillary module with 175.5 mL(STP)/min at a low‐vacuum pressure of 0.042 bar at 850°C, but the asymmetric membrane showing a little bit higher flux at moderate vacuum pressures above 0.07 bar. © 2012 American Institute of Chemical Engineers AIChE J, 58: 3195–3202, 2012 相似文献
18.
Process waters obtained from hydrothermal carbonization (HTC) of wheat straw, a biogas digestate derived thereof, and four woody biomass feedstocks were quantified regarding the total organic carbon (TOC) and selected organic compounds. HTC runs revealed that TOC loads were largely unaffected by process severity or type of feedstock whereas the C2–C6 fatty acids, determined by GC, displayed clear effects of temperature and feedstock. HPLC demonstrated simultaneously the initial increase and subsequent consumption of cellulose‐derived furfural and 5‐hydroxymethylfurfural as well as the increase of the lignin‐derived 2‐methoxyphenol. 2‐Methylbenzofuran, an example for a substance potentially harmful to aquatic biota, was observed in high concentration in the HTC liquor from wheat straw‐based feedstocks. 相似文献
19.
20.
Ai Lun Muggleton Stephen H. Hocquette Céline Gromowski Mark Schmid Ute 《Machine Learning》2021,110(4):695-721
Machine Learning - Given the recent successes of Deep Learning in AI there has been increased interest in the role and need for explanations in machine learned theories. A distinct notion in this... 相似文献