全文获取类型
收费全文 | 291篇 |
免费 | 18篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 86篇 |
金属工艺 | 2篇 |
机械仪表 | 5篇 |
建筑科学 | 13篇 |
能源动力 | 4篇 |
轻工业 | 20篇 |
水利工程 | 6篇 |
石油天然气 | 7篇 |
无线电 | 18篇 |
一般工业技术 | 41篇 |
冶金工业 | 20篇 |
原子能技术 | 4篇 |
自动化技术 | 79篇 |
出版年
2024年 | 3篇 |
2023年 | 8篇 |
2022年 | 2篇 |
2021年 | 10篇 |
2020年 | 18篇 |
2019年 | 11篇 |
2018年 | 15篇 |
2017年 | 10篇 |
2016年 | 20篇 |
2015年 | 11篇 |
2014年 | 16篇 |
2013年 | 22篇 |
2012年 | 16篇 |
2011年 | 31篇 |
2010年 | 13篇 |
2009年 | 9篇 |
2008年 | 11篇 |
2007年 | 9篇 |
2006年 | 8篇 |
2005年 | 3篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 9篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 4篇 |
1984年 | 4篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 5篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1976年 | 4篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1969年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有309条查询结果,搜索用时 15 毫秒
21.
The stability of a fed-batch bioreactor operated with a new control strategy (ED-TOC) during a long-term period was evaluated. The ED-TOC strategy uses solely measurements of DO concentration and volume of the reactor to control the influent flow rate, and so the substrate degradation rate oscillates around its maximal value during the whole filling phase. The bioreactor was tested for the degradation of a wastewater containing 4-chlorophenol (4CP) as a model of an inhibitory compound. The experiment was conducted twice in order to investigate whether results were reproducible. Each set of experiments consisted of two phases: acclimation of the biomass to 4-chlorophenol and operation using the ED-TOC strategy. The main conclusion is that the reactor operated by the ED-TOC strategy is robust and stable in large operation periods. Degradation efficiencies greater than 99% as 4CP and greater than 97% as COD degradation were obtained. Toxicity analysis demonstrates that the bioreactor operated by ED-TOC eliminates the toxicity in the wastewater. Community analysis by DGGE was also conducted. 相似文献
22.
Different interpretations of innovation and innovativeness lead to different approaches and different methods to measure organizational output innovativeness. Two indicators of innovativeness are derived from two divergent approaches: the Referent Innovativeness Index and the Classification Innovativeness Index. The article uses the case of the popular music festival to discuss how these indexes can be operationalized and calculated, as well as to outline the implications of the differences between the methods. 相似文献
23.
Microbiological and Physicochemical Quality Changes in Frankfurters Made from Jumbo Squid (Dosidicus gigas) Mantle Muscle in the Presence and Absence of a Natural Antimicrobial Agent
下载免费PDF全文
![点击此处可从《Journal of Food Safety》网站下载免费的PDF全文](/ch/ext_images/free.gif)
24.
Palomares Iván Martínez-Cámara Eugenio Montes Rosana García-Moral Pablo Chiachio Manuel Chiachio Juan Alonso Sergio Melero Francisco J. Molina Daniel Fernández Bárbara Moral Cristina Marchena Rosario de Vargas Javier Pérez Herrera Francisco 《Applied Intelligence》2021,51(9):6497-6527
Applied Intelligence - The17 Sustainable Development Goals (SDGs) established by the United Nations Agenda 2030 constitute a global blueprint agenda and instrument for peace and prosperity... 相似文献
25.
Iván García-Magariño Rubén Fuentes-Fernández Jorge J. Gómez-Sanz 《Information and Software Technology》2010,52(4):422-435
Computer-Aided Software Engineering (CASE) tools support modeling-related activities in development projects. Given the variety of tools and functionalities, it is quite common to work with several tools in the same project. However, data cannot usually be exchanged between these tools without loss of information. Recent approaches address this model interchange problem using metamodels to characterize the involved information and transformations to export/import it. Nevertheless, most of these solutions focus on the abstract syntax of models. They fail to consider aspects such as the presentation of models or tool-specific information, which are either disregarded or represented in ad-hoc ways that make difficult their processing. In order to overcome these limitations, this paper introduces a framework to define metamodels of CASE tools and a process to carry out the model interchange using them. The proposed metamodels have a modular organization with several internal metamodels. Each of them is aimed at describing some specific information about content, structure and presentation for both models and tools. The paper illustrates this approach with a case study used for comparison with existing works for this problem. 相似文献
26.
García-Montaño J Ruiz N Muñoz I Domènech X García-Hortal JA Torrades F Peral J 《Journal of hazardous materials》2006,138(2):218-225
An environmental study using life cycle assessment (LCA) has been applied to three bench-scale wastewater treatments for Cibacron Red FN-R hetero-bireactive dye removal: artificial light photo-Fenton process, solar driven photo-Fenton process and artificial light photo-Fenton process coupled to a biological treatment. The study is focused on electricity and chemicals consumption, transports and atmosphere and water emissions generated by the different processes involved. Results show that the artificial light photo-Fenton process is the worst treatment in terms of environmental impact. On the other hand, both solar driven and coupled to biological photo-Fenton processes reduce significantly the environmental damage, although none can be identified as the best in all impact categories. The major environmental impact is attributed to the H2O2 consumption and to the electrical energy consumption to run the UVA lamp. An economic analysis of the different photo-Fenton processes has also been performed and the results are discussed together with those obtained from the environmental assessment. 相似文献
27.
Ignacio Vieitez Nicolas Callejas Bruno Irigaray Yenny Pinchak Natalie Merlinski Iván Jachmanián Maria A. Grompone 《Journal of the American Oil Chemists' Society》2014,91(4):655-664
The cost of starting materials for the production of biodiesel is typically 75 % of the final retail price. Oils previously used for frying, waste frying oils (WFO), are a very suitable resource. Repetitive use of oil for frying foods involves high temperature, moisture and aeration for extended periods. The most important deterioration processes triggered by these conditions are hydrolysis and oxidation. In this study, 24 WFO samples of different origins were analyzed and classified as potential starting materials for biodiesel production using three quality parameters representing the main factors that affect the conversion of WFO. These parameters were: acid value, content of polar compounds and content of polymers, which varied in the ranges from 0.2 to 7.6, 14.9 to 43.2 and 0.9 to 15.2 %, respectively. Ester content obtained using conventional transesterification (TE) for WFO conversion decreased with increased levels of WFO deterioration determined by any of the three parameters noted above. TE products obtained had ester content between 81.4 and 95.7 %. Total ester content of a WFO sample with relatively low %AV could be increased to 96.5 % using a two-stage base catalysis TE. Finally, conversion of WFO samples resulted in ester contents of 89.0 and 91.3 %, respectively, when transesterified by conventional TE. After blending up to 10 % with refined oil, the ester content achieved was near 96.5 %. Thus, the blending represents an alternative for obtaining a product with suitable ester content. 相似文献
28.
Rossato Janine I.; Bonini Juliana S.; Coitinho Adriana S.; Vianna Monica R. M.; Medina Jorge H.; Cammarota Martín; Izquierdo Iván 《Canadian Metallurgical Quarterly》2004,118(3):563
The gamma aminobutyric acid-A (GABAA) agonist, muscimol, the glutamate N-methyl-D-aspartate (NMDA) receptor antagonist, D-2-amino-5-phosphonopentanoic acid (AP5), and the inhibitor of the extracellularly regulated kinases (ERKs), UO 126, cause retrograde amnesia when administered to the hippocampus. In the present study, the authors found that they all cause retrograde amnesia for 1-trial inhibitory avoidance, not only when infused into the dorsal CA1 region of the hippocampus, but also when infused into the basolateral amygdala or the entorhinal, parietal, and posterior cingulate cortices. The posttraining time course of the effect of each drug was, however, quite different across brain structures. Thus, in all of them, NMDA receptors and the ERK pathway are indispensable for memory consolidation, and GABAA receptor activation inhibits memory consolidation: but in each case, their influence is interwoven differently. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
29.
Iván Jachmanián Lucía Margenat Ana I. Torres Maria A. Grompone 《Journal of the American Oil Chemists' Society》2007,84(6):597-601
The solubility of different ethyl esters derivatized from hake liver oil in supercritical carbon dioxide was studied. A selectivity
factor was used to determine optimal conditions to fractionate the ethyl ester mixture. A strong influence of solvent pressure
and temperature was observed within 8.63–18.04 MPa and 40–70 °C. The lowest total solubility of the ethyl ester mixture was
obtained when using supercritical carbon dioxide at the lowest density (the lowest pressure and the highest temperatures value
tested). The highest discrimination against long-chain polyunsaturated fatty acids (e.g. EPA and DHA) was also obtained at
these above conditions. Conversely, higher solubility and lower selectivity were obtained when solvent density increased.
Considering this inverse correlation between selectivity and solubility, a single-step batch-fractionation process was designed
to increase the 22:6 ethyl ester content from an initial value of 17.5% in the starting material to 55% in the final extract. 相似文献
30.