全文获取类型
收费全文 | 615篇 |
免费 | 57篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 159篇 |
金属工艺 | 4篇 |
机械仪表 | 7篇 |
建筑科学 | 28篇 |
能源动力 | 24篇 |
轻工业 | 88篇 |
水利工程 | 7篇 |
石油天然气 | 1篇 |
无线电 | 69篇 |
一般工业技术 | 119篇 |
冶金工业 | 50篇 |
原子能技术 | 7篇 |
自动化技术 | 106篇 |
出版年
2024年 | 2篇 |
2023年 | 6篇 |
2022年 | 24篇 |
2021年 | 33篇 |
2020年 | 23篇 |
2019年 | 15篇 |
2018年 | 21篇 |
2017年 | 25篇 |
2016年 | 22篇 |
2015年 | 19篇 |
2014年 | 48篇 |
2013年 | 43篇 |
2012年 | 34篇 |
2011年 | 32篇 |
2010年 | 27篇 |
2009年 | 28篇 |
2008年 | 21篇 |
2007年 | 29篇 |
2006年 | 20篇 |
2005年 | 24篇 |
2004年 | 21篇 |
2003年 | 10篇 |
2002年 | 18篇 |
2001年 | 12篇 |
2000年 | 2篇 |
1999年 | 10篇 |
1998年 | 20篇 |
1997年 | 10篇 |
1996年 | 11篇 |
1995年 | 5篇 |
1994年 | 8篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1990年 | 5篇 |
1988年 | 2篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1980年 | 2篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1969年 | 2篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有673条查询结果,搜索用时 187 毫秒
111.
112.
Alfonso Policicchio Raffaele Filosa Salvatore Abate Giovanni Desiderio Elio Colavita 《Journal of Porous Materials》2017,24(4):905-922
The aim of this comprehensive review on materials for methane storage application is to understand which are the best conditions and the best materials for their use for the implementation of storage tank. The research was focused on two different families of samples that up to now appear like the most promising. In particular, Activated carbon and metal organic framework were analyzed and an overall picture was extrapolated. Analysis of the structural parameters and adsorption capacities were evaluated and relation between them were obtained. A comparison of values available in literature was done and, when possible, laboratory tests were performed. The presented results allow to identify potential materials with high specific storage capacity and to verify their performances in optimized conditions. This work represents the starting point for a real and efficient method to the methane storage as a starting point for the development of Adsorbed Natural Gas technology for static and/or automotive applications. 相似文献
113.
114.
M. Luisa Demattè Gesualdo M. Zucco Sergio Roncato Paola Gatto Elena Paulon Raffaele Cavalli Michela Zanetti 《Holz als Roh- und Werkstoff》2018,76(4):1093-1100
The effect a wooden-built environment exerts on the physical and psychological well-being of people has mostly been investigated by evaluation, through a limited number of sensory modalities, of small size stimuli. In this research, two real-size wooden and plaster indoor settings were used to examine the influence of wood on people’s emotions and perceptions. Three questionnaires assessed participants’ multimodal sensory, affective, and cognitive responses to the settings (Semantic Differential questionnaire), their emotional state (Positive and Negative Affect Schedule), and their environmental behaviour and biophilia degree (Nature Relatedness Scale). The results revealed that wood induces more positive emotions than plaster, and that individual biophilia degree appears to influence the tactile, auditory, and olfactory evaluation of the settings. It furthermore indicates how wood used in real buildings positively influences human psychological well-being and highlights the importance of considering multiple sensory modalities when investigating wood–human interaction. 相似文献
115.
We address the problem of time-base synchronization for MPEG services in the presence of network jitter. The conventional methods to obtain a stable clock indication are based on Phase Locked Loops (PLLs). They have the disadvantage of a long startup phase and thus are unsuitable for services that require simultaneous accuracy and rapidity. We develop a new time-base synchronization technique based on a Least-square Linear Regression algorithm (LLR). We show that LLR is able to perform time-base synchronization with the same accuracy as of a PLL and with a substantial gain of rapidity. Finally, we discuss the implementation of the LLR technique as an intermediate time-base synchronization level between the network and a generic multimedia application. 相似文献
116.
117.
Vincenzo Fogliano Alberto Ritieni Simona M Monti Monica Gallo Dorotea Della Medaglia Maria Luisa Ambrosino Raffaele Sacchi 《Journal of the science of food and agriculture》1999,79(13):1803-1808
The antioxidant activity of two virgin olive oils, obtained from the same olive (Olea europaea sativa) batch but processed with different hammer crushing conditions, was evaluated by measuring their protective action towards linoleic acid peroxidation in a micellar system. The antioxidant efficiency (AE) of the oil phenolic fraction was higher when the olives were processed with a higher hammer crusher rotation rate. HPLC analysis demonstrated that one of the main derivatives of oleuropein, indicated as 3,4-DHPEA-EDA (the dialdehydic form of elenolic acid linked with 3,4-dihydroxyphenylethanol), is present only in the oil with higher AE. 3,4-DHPEA-EDA showed the greatest antioxidant ability among virgin olive oil phenols. Its greater efficiency in the micellar system in comparison with 3,4-dihydroxyphenylethanol (3,4-DHPEA) is related to its greater lipophilicity. It is suggested that the behaviour in the water–micellar environment is representative of that in a real system such as tomato-based sauce with added virgin olive oil. © 1999 Society of Chemical Industry 相似文献
118.
Influence of Zinc on Distiller's Yeast: Cellular Accumulation of Zinc and Impact on Spirit Congeners
Raffaele de Nicola Nichola Hall Stuart G. Melville Graeme M. Walker 《Journal of the Institute of Brewing》2009,115(3):265-271
Accumulation of zinc by a whisky distilling yeast strain of Saccharomyces cerevisiae was studied during fermentation of malt wort and synthetic defined medium. Zinc uptake by yeast cells was very rapid in malt wort, as zinc (0.32 μg/mL) was completely removed from the fermentation medium within one hour. The type of fermentable carbohydrate had an impact on the kinetics of zinc accumulation, with maltose most effective at enhancing metal uptake at zinc concentrations above 3.2 μg/mL. Enriching yeast cells with zinc by “preconditioning” impacted on the production of flavour congeners in the distillates produced from fermented cultures. Such distillates were characterised by an altered flavour and aroma profile. In particular, the production of some higher alcohols increased when yeast cells were preconditioned with zinc. This phenomenon is yeast strain related. Industrial fermentation processes, including brewing and distilling, may benefit from optimization of zinc bioavailability in yeast cultures resulting in more efficient fermentations and improved product quality. 相似文献
119.
120.
Energetic and exergetic analysis of steam production for the extraction of coniferous essential oils
Bioenergy production is optimal when the energy production process is both efficient and benefits from local resources. Energetic and exergetic analyses are applied to highlight efficiency differences between small-size systems that are based on the co-generation of heating and power (CHP) versus the co-generation of heating and power with steam production (CHP-S). Both systems use the Organic fluid Rankine Cycle (ORC).The recovery of heat from flue gases is considered to be a way of increasing energy efficiency. In the CHP-S case, steam (at low pressure) is used to extract essential oils from fresh twigs and needles of coniferous trees throughout a steam distillation process. When the systems work at a thermal combustion power of 1350 kW, energetic analysis shows that the energy efficiency of the CHP-S plant (89.4%) is higher than that of the CHP plant (77.9%). Exergetic analysis shows that the efficiency of the CHP-S plant is 2.2% higher than that of the CHP plant. 相似文献