全文获取类型
收费全文 | 706篇 |
免费 | 48篇 |
专业分类
电工技术 | 6篇 |
综合类 | 1篇 |
化学工业 | 164篇 |
金属工艺 | 9篇 |
机械仪表 | 9篇 |
建筑科学 | 30篇 |
矿业工程 | 1篇 |
能源动力 | 49篇 |
轻工业 | 46篇 |
水利工程 | 9篇 |
石油天然气 | 2篇 |
无线电 | 99篇 |
一般工业技术 | 84篇 |
冶金工业 | 13篇 |
自动化技术 | 232篇 |
出版年
2023年 | 6篇 |
2022年 | 33篇 |
2021年 | 39篇 |
2020年 | 27篇 |
2019年 | 23篇 |
2018年 | 33篇 |
2017年 | 38篇 |
2016年 | 44篇 |
2015年 | 26篇 |
2014年 | 46篇 |
2013年 | 48篇 |
2012年 | 40篇 |
2011年 | 60篇 |
2010年 | 51篇 |
2009年 | 45篇 |
2008年 | 31篇 |
2007年 | 42篇 |
2006年 | 23篇 |
2005年 | 16篇 |
2004年 | 12篇 |
2003年 | 6篇 |
2002年 | 8篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 8篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 6篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1982年 | 2篇 |
1980年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有754条查询结果,搜索用时 570 毫秒
81.
82.
Apostolos Fysikopoulos Georgios Pastras Theocharis Alexopoulos George Chryssolouris 《The International Journal of Advanced Manufacturing Technology》2014,73(9-12):1437-1452
Energy efficiency has become a very significant factor, requiring its inclusion in the manufacturing decision-making attributes. This paper proposes a generalized approach to manufacturing energy efficiency. The basic element of the approach is the division of energy efficiency definition and study into four manufacturing levels, namely process, machine, production line, and factory. Process-level definitions are provided for the majority of manufacturing processes. A machine-level study indicates and solves difficulties, generated by the workpiece geometry, and points out the interaction with the process level through factors, such as the process time. Moreover, machine tool peripherals are responsible for a significant portion of the consumed energy, and classification based on the dependence of their consumption on process variables is required. Studies made on the production line and factory levels show that energy efficiency, at these levels, is heavily dependent on production planning and scheduling and can be improved through the appropriate utilization of machines, with the inclusion of shutdown and eco-modes. Finally, a case study is presented, showing that many of the difficulties towards the optimization of energy efficiency can be dealt with successfully, using the proposed generalized approach. 相似文献
83.
George D. Verros Dimitris S. Achilias Georgios I. Giannoukos 《Polymer Engineering and Science》2011,51(4):670-678
In this work a detailed mathematical model for free radical suspension polymerization of methyl methacrylate (MMA) in water is developed. This model is based on sound principles such as the free volume theory to account for the diffusion limited reactions in suspension polymerization. Additionally, the complex polymerization kinetics process of the aqueous suspension polymerization of MMA is studied as a one‐dimensional numerical experiment. For this purpose, the polymerization process is modeled as a moving boundary mass transfer problem coupled with polymerization reactions. The Galerkin finite element method is used to simultaneously solve the nonlinear governing equations. The model predictions for conversion and average molecular weights vs. time were found to be in close agreement with laboratory data. It is believed that this work, as it provides fundamental understanding of the process, it might contribute to a more rational design of polymerization reactors. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers 相似文献
84.
Linda Brinkhaus Georgios Katsukis Jenny Malig Rubén D. Costa Miguel Garcia‐Iglesias Purificación Vázquez Tomás Torres Dirk M. Guldi 《Small (Weinheim an der Bergstrasse, Germany)》2013,9(13):2348-2357
In contrast to pristine zinc phthalocyanine (1), zinc phthalocyanine based oPPV‐oligomers (2–4) of different chain lengths interact tightly and reversibly with graphite, affording stable and finely dispersed suspensions of mono‐ to few‐layer graphene—nanographene (NG)—that are photoactive. The p‐type character of the oPPV backbones and the increasing length of the oPPV backbones facilitate the overall π–π interactions with the graphene layers. In NG/2, NG/3, and NG/4 hybrids, strong electronic coupling between the individual components gives rise to charge transfer from the photoexcited zinc phthalocyanines to NG to form hundreds of picoseconds lived charge transfer states. The resulting features, namely photo‐ and redoxactivity, serve as incentives to construct and to test novel solar cells. Solar cells made out of NG/4 feature stable and repeatable photocurrent generation during several ‘on‐off’ cycles of illumination with monochromatic IPCE values of around 1%. 相似文献
85.
Antonios Kiosseoglou Georgios Doxastakis Stefan Alevisopoulos & Stefan Kasapis 《International Journal of Food Science & Technology》1999,34(3):253-263
Summary Protein isolates of Lupinus albus were obtained from full fat and defatted lupin flour using isoelectric precipitation or dialysis. Calorimetric tests demonstrated that the main protein fractions of the isolates denature well below 100 °C. Mechanical spectra of isolate dispersions obtained at 80 °C indicated the formation of a 'pseudogel' whose cohesion increased during cooling to 10 °C. Subsequent heating to 90 °C encouraged extensive formation of disulphide bonds as it produced gels that were insoluble in sodium dodecyl sulphate and urea solutions. Dialysis produced isolates of lower gelling concentrations, which also formed networks of a stronger relative elastic character. The presence of NaCl at concentrations up to 0.5 m had a reinforcing effect on networks. Protein over-aggregation caused the opposite effect at higher salt levels. Finally, a comparison with results in the literature on soybean protein gelation suggested similar denaturation temperatures and a common pattern of structure formation for the two legume proteins. 相似文献
86.
Emmanuel Kokkinakis Georgios Boskou Georgios A. Fragkiadakis Aikaterini Kokkinaki Nikolaos Lapidakis 《Food Control》2007,18(12):1538-1546
The efficiency of the good agricultural practices (GAP) protocol AGRO 2-1 & 2-2, in advancing microbiological-quality of tomatoes and peppers, was studied in greenhouses at Ierapetra, Crete, Greece. The 240 tested vegetables-samples, produced under AGRO 2-1 & 2-2, showed satisfactory quality: Listeria monocytogenes absent per 25 g; Escherichia coli < 20 Colony Forming Units per gram (CFU/g); total coliforms 4.37–4.68 log CFU/g; aerobic plate counts 5.78–5.92 log CFU/g. Based on actual results and practices evaluation, we conclude that AGRO 2-1 & 2-2 can reduce microbial hazards for consumers and furthermore can establish practices in compliance to basic Euro-Retailer-Produce GAP (EUREPGAP) requirements. 相似文献
87.
Fuel cell testing and standardization thematic network (FCTESTNET) was a Thematic Network funded by the European Commission under the Fifth Framework Program (FP5), which was comprised of 55 European partners. The project concluded in 2006 and the main output was the collection and compilation of agreed testing procedures for different fuel cell technologies (PEM, SOFC, MCFC), applications (stationary, portable, transport), as well as balance of plant. 相似文献
88.
Aziz S. Mousas Angelos-Christos G. Anadiotis Georgios V. Lioudakis John P. Papanis Panagiotis K. Gkonis Dimitra I. Kaklamani Iakovos S. Venieris 《Wireless Personal Communications》2014,76(1):99-119
This paper presents an integrated security architecture for heterogeneous distributed systems. Based on the MPEG-21 standard data structures and the MPEG-M standard services, the proposed architecture provides a unified, fine-grained solution for protecting each information unit circulated in the system. In this context, a novel scheme for translating the access control rules, initially expressed by means of the standard MPEG-21 Rights Expression Language, into Ciphertext-Policy Attribute-Based Encryption access trees is introduced, thereby enabling offline authorization based on the users’ attributes, also encapsulated and certified using MPEG-21 licenses. The proposed framework provides a detailed approach in all the steps of the information protection process, from attribute acquisition to data encryption and decryption. 相似文献
89.
90.
Georgios Papadopoulos Constantine Anetakis 《Materials Science and Engineering: B》2011,176(6):500-503
With the goal to develop iron oxide quantum dots we developed a simple method to spread horse spleen ferritin monolayers on a Si (1 0 0) surface. Application of atomic force microscopy and spectroscopic ellipsometry showed the existence of regions with dense ferritin monolayers. Application of transmission electron microscopy identified the core of the spread ferritin as FeO nanocrystals. 相似文献