全文获取类型
收费全文 | 532篇 |
免费 | 49篇 |
专业分类
电工技术 | 3篇 |
化学工业 | 175篇 |
金属工艺 | 4篇 |
机械仪表 | 3篇 |
建筑科学 | 28篇 |
能源动力 | 23篇 |
轻工业 | 80篇 |
水利工程 | 7篇 |
无线电 | 39篇 |
一般工业技术 | 101篇 |
冶金工业 | 13篇 |
原子能技术 | 6篇 |
自动化技术 | 99篇 |
出版年
2024年 | 2篇 |
2023年 | 8篇 |
2022年 | 47篇 |
2021年 | 32篇 |
2020年 | 23篇 |
2019年 | 14篇 |
2018年 | 22篇 |
2017年 | 25篇 |
2016年 | 22篇 |
2015年 | 18篇 |
2014年 | 41篇 |
2013年 | 34篇 |
2012年 | 32篇 |
2011年 | 31篇 |
2010年 | 27篇 |
2009年 | 27篇 |
2008年 | 16篇 |
2007年 | 19篇 |
2006年 | 14篇 |
2005年 | 20篇 |
2004年 | 15篇 |
2003年 | 9篇 |
2002年 | 18篇 |
2001年 | 10篇 |
2000年 | 2篇 |
1999年 | 8篇 |
1998年 | 5篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1969年 | 1篇 |
排序方式: 共有581条查询结果,搜索用时 10 毫秒
71.
Alessandro Pagano Irene Pluchinotta Raffaele Giordano Anna Bruna Petrangeli Umberto Fratino Michele Vurro 《Water Resources Management》2018,32(6):2131-2145
The availability and the quality of drinking water are key requirements for the well-being and the safety of a community, both in ordinary conditions and in case of disasters. Providing safe drinking water in emergency contributes to limit the intensity and the duration of crises, and is thus one of the main concerns for decision-makers, who operate under significant uncertainty. The present work proposes a Decision Support System for the emergency management of drinking water supply systems, integrating: i) a vulnerability assessment model based on Bayesian Belief Networks with the related uncertainty assessment model; ii) a model for impact, and related uncertainty assessment, based on Bayesian Belief Networks. The results of these models are jointly analyzed, providing decision-makers with a ranking of the priority of intervention. A GIS interface (G-Net) is developed to manage both input spatial information and results. The methodology is implemented in L’Aquila case study, discussing the potentialities associated to the use of the tool dealing with information and data uncertainty. 相似文献
72.
Networks and Spatial Economics - European gas markets have gone through profound restructuring processes in the last 20 years. Directive 98/30/EC represented the first attempt to liberalize this... 相似文献
73.
Pastore Annalisa; Francesco Raffaele De; Morelli Maria Antonietta Castiglione; Nalis Dominique; Cortese Riccardo 《Protein engineering, design & selection : PEDS》1992,5(8):749-757
LFB1/HNF1 and LFB3/HNF1ß bind DNA as dimers and formheterodimers together in vivo and in vitro. The dimerizationdomain has been located in both proteins in the 32 N-terminalresidues. In previous papers we have described the conformationalstability as determined by CD and the secondary structure byNMR studies of a peptide with the amino acid sequence of thedimerization domain of LFB1/ HNF1. This study presents a morecomplete characterization of similar synthetic peptides spanningthe LFB3/HNF1ß dimerization domain and the /ßheterodimer. The HNF1 peptides represent an example of structureswhich cannot be determined by NOE data alone because they arenot sufficient to define one unique solution. An approach ispresented which combines NMR data, the protein structure databaseand structural analyses according to known principles of proteinstructure. On this basis we are able to determine possible solutionsand to identify a four helix bundle as the structure most consistentwith the experimental evidence. 相似文献
74.
75.
76.
Gianluca Bianchini Marcello Crucianelli Claudia Crestini Raffaele Saladino 《Topics in Catalysis》2006,40(1-4):221-227
Polymer-supported methyltrioxorhenium (MTO) compounds are shown to act as efficient and selective catalysts for the oxy-functionalization
of C–H bonds in representative hydrocarbon derivatives (leading to the corresponding alcohols or ketones), using H2O2 as oxidant. The different supports used for the heterogenation of MTO, such as poly(4-vinylpyridine), poly(4-vinylpyridine)-N-oxide and polystyrene resins, all showed different catalytic behaviour in terms of substrate conversion and product yield,
depending on the experimental conditions used. It is noteworthy that the novel heterogeneous catalysts were found to be stable,
it being possible to effect their recover and recycle at least five times without appreciable loss of activity. 相似文献
77.
The oxidation by H2O2 of 3,4-dihydroxybenzoic acid (3,4-DHB) in aqueous/goethite slurry at varying operating conditions (catalyst load, temperature, pH, substrate and hydrogen peroxide starting concentration) is investigated. At adopted catalyst loads the observed kinetic developments are consistent with a non-radicalic oxidation mechanism involving the interaction between hydrogen peroxide and 3,4-DHB acid both adsorbed on the active sites of the catalyst. The temperature dependence of rate parameters for the proposed model is also assessed. 相似文献
78.
Raffaele Landolfo Lucrezia Cascini Francesco Portioli 《Frontiers of Architecture and Civil Engineering in China》2011,5(3):304-314
Nowadays, the construction sector is more and more oriented toward the promotion of sustainability in all its activities.
The goal to achieve is the optimization of performances, over the whole life-cycle, with respect to environmental, economic
and social requirements. According to the latest advances, the concept of sustainability applied to constructions covers a
number of branches such as life-cycle costing, ecology, durability and even structural design. Several procedures and design
tools have been implemented in the framework of international research. Indeed the current trend in civil engineering research
is moving towards life-time engineering, with the aim to implement integrated methodologies to consider as a whole all the
sustainability requirements according to time-dependent multi-performance-based design approaches. Following a general introduction
of the concept of sustainability applied to constructions, this paper presents an overview of life-time engineering methodologies
according to the current state-of-the-art. In particular the methods currently received by International Standards are discussed.
A special focus is devoted to the durability design of metal structures with respect to the degradation phenomena able to
impair the structural capacity over time. Finally a proposal towards an integrated approach to life-time engineering design
of steel structures and needs for further advances are presented. 相似文献
79.
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
80.