全文获取类型
收费全文 | 699篇 |
免费 | 32篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 16篇 |
化学工业 | 143篇 |
金属工艺 | 11篇 |
机械仪表 | 4篇 |
建筑科学 | 55篇 |
能源动力 | 28篇 |
轻工业 | 86篇 |
水利工程 | 2篇 |
石油天然气 | 1篇 |
无线电 | 27篇 |
一般工业技术 | 125篇 |
冶金工业 | 65篇 |
原子能技术 | 6篇 |
自动化技术 | 164篇 |
出版年
2023年 | 5篇 |
2022年 | 7篇 |
2021年 | 13篇 |
2020年 | 10篇 |
2019年 | 12篇 |
2018年 | 24篇 |
2017年 | 17篇 |
2016年 | 17篇 |
2015年 | 21篇 |
2014年 | 20篇 |
2013年 | 45篇 |
2012年 | 29篇 |
2011年 | 45篇 |
2010年 | 35篇 |
2009年 | 35篇 |
2008年 | 41篇 |
2007年 | 27篇 |
2006年 | 30篇 |
2005年 | 35篇 |
2004年 | 23篇 |
2003年 | 20篇 |
2002年 | 22篇 |
2001年 | 8篇 |
2000年 | 15篇 |
1999年 | 14篇 |
1998年 | 21篇 |
1997年 | 18篇 |
1996年 | 12篇 |
1995年 | 11篇 |
1994年 | 15篇 |
1993年 | 9篇 |
1992年 | 6篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 6篇 |
1986年 | 2篇 |
1985年 | 9篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 5篇 |
1975年 | 2篇 |
1970年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有733条查询结果,搜索用时 15 毫秒
31.
Soil moisture retrieval using thermal inertia, determined with visible and thermal spaceborne data, validated for European forests 总被引:2,自引:0,他引:2
Willem W. Verstraeten Frank Veroustraete Ief Grootaers 《Remote sensing of environment》2006,101(3):299-314
Variations in soil moisture strongly affect surface energy balances, regional runoff, land erosion and vegetation productivity (potential crop yield). Hence, the detection of soil moisture content (SMC) is very valuable in the social, economic, humanitarian (food security) and environmental segments of society. A method to estimate SMC from optical and thermal spectral information of METEOSAT imagery based on thermal inertia (TI) is presented. Minimum and maximum TI values from time series are combined in the Soil Moisture Saturation Index (SMSI). To convert surface to soil profile values, a Markov type filter is used, based on a simple two layer water balance equation (the surface layer and the reservoir below) and an autocorrelation function. Ten-daily SMC values are compared with up-scaled (using AVHRR/NDVI) observations on 10 EUROFLUX sites in Europe for the 1997 growing season (March-October). Moreover, the thermal inertia approach is compared for 1997, with ERS Scatterometer data for eight EUROFLUX sites. METEOSAT pixels are up-scaled to accommodate the ERS Scatterometer spatial resolution. The regression coefficients (slope, intercept and R2) of the thermal inertia approach versus the up-scaled soil moisture observations from EUROFLUX sites vary between 0.811-1.148, − 0.0029-0.66 and 0.544-0.877, respectively, with a RRMSE range of 3.9% to 35.7%. The regression coefficients of the comparison of ERS Scatterometer derived Soil Water Index (SWI) versus the up-scaled Soil Moisture Saturation Index for the pooled case (binning the eight EUROFLUX sites) are 0.587, 0.105 and 0.441, respectively, with a RRMSE of 38%. A simple error propagation model applied for the thermal inertia approach reveals that the absolute and relative errors of the obtained soil moisture content is at least 0.010 m3 m− 3 or 2.0% with a SMC of 0.203 m3 m− 3. Recommendations are made to test and implement the TI methodology using NOAA/AVHRR imagery. 相似文献
32.
Klaus Havelund Willem Visser 《International Journal on Software Tools for Technology Transfer (STTT)》2002,4(1):8-20
This paper introduces a special section of the STTT journal containing a selection of papers that were presented at the 7th
international SPIN workshop, Stanford, 30 August – 1 September 2000. The workshop was named SPIN Model Checking and Software
Verification, with an emphasis on model checking of programs. The paper outlines the motivation for stressing software verification,
rather than only design and model verification, by presenting the work done in the Automated Software Engineering group at
NASA Ames Research Center within the last 5 years. This includes work in software model checking, testing like technologies
and static analysis.
Published online: 2 October 2002 相似文献
33.
34.
Monster A. Willem Pittore J. Barrie W. 《IEEE transactions on bio-medical engineering》1980,(2):110-112
Inability to predict the intramusclar orientation, depth, and distribution of a motor unit's muscle fibers within a human skeletal muscle complicates unit size estimation. A data collection system is described that is suitable for systematic study of this problem. 相似文献
35.
Architectural drawing systems are discussed, with emphasis on quality of user-interfaces and improvement offered by new computing technology. EdCAAD's STAG drawing system is described, demonstrating the benefits of newer technology. 相似文献
36.
Instructions for Authors
Instructions for Authors 相似文献37.
A multicomponential model of authenticity is presented which includes psychosocial, cultural, intrapsychic, personality and capacity related and neurobiological aspects of authenticity. Genetic, political and ethnic influences could also involved in authentic etiology. More research is needed into the correlates (and their interactions) of authenticity in order to develop adequate intervention and prevention programs for individuals who demonstrate a lack of authenticity. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
38.
Cognitive reactivity (CR) is a psychological vulnerability marker of depression, whereas response to acute tryptophan depletion (ATD; a serotonergic challenge procedure) is a biological vulnerability marker. The aim of this study was to investigate the relationship between these markers. Thirty-nine remitted depressed patients participated in 2 ATD sessions in a double-blind crossover design. CR, assessed prior to the ATD sessions, predicted depressive response to high-dose ATD. CR also diminished the effects of 2 known predictors of ATD response: gender and residual symptoms. Neuroticism and behavioral inhibition were unrelated to ATD response. CR is associated with an increased sensitivity to reductions of serotonin concentrations. These findings present a small step toward unifying cognitive and neurobiological theories of depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
39.
Messai A. Mamo Neil J. Coville Willem A. L. van Otterlo 《Fullerenes, Nanotubes and Carbon Nanostructures》2007,15(5):341-352
A series of C60-containing polymers were synthesized by the co-polymerization of a C60-cyclopentadiene cycloadduct and norbornene in varying ratios. The polymerization was facilitated by a catalytic amount of Grubbs second generation catalyst and the co-polymers formed were investigated by spectroscopic and thermal techniques. 相似文献
40.
Taylor Steven; Zvolensky Michael J.; Cox Brian J.; Deacon Brett; Heimberg Richard G.; Ledley Deborah Roth; Abramowitz Jonathan S.; Holaway Robert M.; Sandin Bonifacio; Stewart Sherry H.; Coles Meredith; Eng Winnie; Daly Erin S.; Arrindell Willem A.; Bouvard Martine; Cardenas Samuel Jurado 《Canadian Metallurgical Quarterly》2007,19(2):176
Accumulating evidence suggests that anxiety sensitivity (fear of arousal-related sensations) plays an important role in many clinical conditions, particularly anxiety disorders. Research has increasingly focused on how the basic dimensions of anxiety sensitivity are related to various forms of psychopathology. Such work has been hampered because the original measure--the Anxiety Sensitivity Index (ASI)--was not designed to be multidimensional. Subsequently developed multidimensional measures have unstable factor structures or measure only a subset of the most widely replicated factors. Therefore, the authors developed, via factor analysis of responses from U.S. and Canadian nonclinical participants (n = 2,361), an 18-item measure, the ASI-3, which assesses the 3 factors best replicated in previous research: Physical, Cognitive, and Social Concerns. Factorial validity of the ASI-3 was supported by confirmatory factor analyses of 6 replication samples, including nonclinical samples from the United States and Canada, France, Mexico, the Netherlands, and Spain (n = 4,494) and a clinical sample from the United States and Canada (n = 390). The ASI-3 displayed generally good performance on other indices of reliability and validity, along with evidence of improved psychometric properties over the original ASI. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献