全文获取类型
收费全文 | 291篇 |
免费 | 11篇 |
专业分类
电工技术 | 3篇 |
化学工业 | 63篇 |
金属工艺 | 3篇 |
机械仪表 | 16篇 |
建筑科学 | 2篇 |
矿业工程 | 2篇 |
能源动力 | 13篇 |
轻工业 | 21篇 |
无线电 | 31篇 |
一般工业技术 | 43篇 |
冶金工业 | 42篇 |
原子能技术 | 2篇 |
自动化技术 | 61篇 |
出版年
2024年 | 2篇 |
2022年 | 7篇 |
2021年 | 11篇 |
2020年 | 9篇 |
2019年 | 8篇 |
2018年 | 5篇 |
2017年 | 7篇 |
2016年 | 5篇 |
2015年 | 7篇 |
2014年 | 11篇 |
2013年 | 16篇 |
2012年 | 18篇 |
2011年 | 15篇 |
2010年 | 11篇 |
2009年 | 12篇 |
2008年 | 12篇 |
2007年 | 13篇 |
2006年 | 11篇 |
2005年 | 5篇 |
2004年 | 5篇 |
2003年 | 9篇 |
2002年 | 6篇 |
2001年 | 1篇 |
2000年 | 9篇 |
1999年 | 6篇 |
1998年 | 15篇 |
1997年 | 16篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 9篇 |
1993年 | 6篇 |
1992年 | 3篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1971年 | 1篇 |
1970年 | 2篇 |
排序方式: 共有302条查询结果,搜索用时 0 毫秒
21.
A comprehensive investigation of dye–chitosan blended films for green chemistry applications 下载免费PDF全文
Vito Rizzi Alessandra Longo Tiziana Placido Paola Fini Jennifer Gubitosa Teresa Sibillano Cinzia Giannini Paola Semeraro Esther Franco Marcela Ferrandiz Pinalysa Cosma 《应用聚合物科学杂志》2018,135(10)
In this paper, the ability of chitosan film to remove dyestuff from wastewater was evaluated for environmental applications, using three commercial direct azo dyes. Two chitosan films were adopted: the standard one prepared following a well‐known procedure to form it, and a novel one, with a weakly acidic character. Moreover, to improve the adsorption process, the hydrophobic character of the films was investigated. The pH of the dye solutions was also changed, showing an excellent ability in dye removal at pH 12. The films were characterized by means of spectroscopic and morphologic methods to better understand the nature of interactions between dyes and chitosan chains. Swelling ratio measurements were also performed. All analyses suggest that all dyes showed a strong affinity to chitosan polymer chains, with the presence of extended hydrogen bonds and Van der Waals forces perturbing the chitosan network. Interestingly, very good results were obtained in recycling experiments related to the dyeing capacities of chitosan blended films in the presence of textiles. An ecofriendly application is thus presented in this paper. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45945. 相似文献
22.
A computer running under a Unix operating system is an excellent host on which to develop software for target systems which have the same type of microprocessor as the host computer. Unfortunately, facilities for preparing executable modules able to be sent to an EPROM programmer or to be loaded onto a RAM portion of target memory space are lacking in standard Unix. These facilities can be improved in any version of Unix without the need for expensive software using the set of commands presented in this paper. 相似文献
23.
This paper describes the energy consumption performance of sea-going ships engaged in the EU27 seaborne trades based on data and parameters resulting from the EX-TREMIS (EXploring non road TRansport EMISsions in Europe) database. EX-TREMIS is a comprehensive database of fleet and transport activity data, specific energy consumption, emission factors and total emissions from rail, maritime and air transport in the European Union. The EX-TREMIS maritime model derives from a mixture of top–down and bottom–up approaches for estimating pollutant emissions from shipping activities. The model did not use direct observations of actual trips, but empirically derived the number of equivalent-ships. Cargo type shipments were linked to seven ship type categories for which a further segmentation by ship size (three length classes), type and age of the main engine and type of fuel was applied. 相似文献
24.
Marcio Giannini Pereira José Antonio Sena Marcos Aurélio Vasconcelos Freitas Neilton Fidelis da Silva 《Renewable & Sustainable Energy Reviews》2011,15(3):1427-1441
Most developing countries include rural electrification programs in their efforts to improve social conditions. There are, however, several obstacles to the evaluation of such programs and therefore of their social, economic, environmental and energy impacts on the target population, particularly on impoverished communities located in remote areas. Evaluation of the efficacy of public policies aimed at rural electrification in South Africa, China, India and Brazil enables such actions to be quantified and re-considered so as to bolster the sustainability of their planning and implementation and also so as to enable comprehension of the significance of access to electricity in relation to other aspects of the drive to improve living standards. The provision of electric energy amounts to more than access to a public service and should be considered an essential right, in a context of social equity and justice, which permits social integration and the access to other equally essential services. 相似文献
25.
Marcio Giannini Pereira Cristiane Farias Camacho Marcos Aurélio Vasconcelos Freitas Neilton Fidelis da Silva 《Renewable & Sustainable Energy Reviews》2012,16(6):3786-3802
Renewable energy offers a range of options with which to meet the growing demand for energy, particularly in the context of the pursuit (especially in developing countries) of economic development which takes into account social and environmental issues. Brazil has abundant natural sources of renewable energy, such as wind and solar power, hydraulic energy, small hydroelectric plants, ethanol and bio-diesel. These sources form part of the Brazilian strategy aimed at satisfying the demand for 6300 MW of fresh capacity per year arising out of projected economic growth of 5.1% per year over the next 10 years. Renewable energy sources currently provide 47.2% of the internal supply of primary energy in Brazil. Brazil has been pursuing a strategy of maintaining its renewable energy matrix and developing and providing incentives for further low carbon initiatives.In this study we set out an overview of the renewable energy options available in Brazil, their current status, the main positive results obtained to date and future potential. We describe the market for renewable energy in Brazil and examine specific public policies aimed at overcoming barriers to this market, thereby promoting its consolidation and expansion. 相似文献
26.
Shah Ghazanfar Ali Polette Arnaud Pernot Jean-Philippe Giannini Franca Monti Marina 《Engineering with Computers》2021,37(4):2891-2909
Engineering with Computers - This paper introduces a new fitting approach to allow an efficient part-by-part reconstruction or update of editable CAD models fitting the point cloud of a digitized... 相似文献
27.
Simulation models are a practical tool for reengineering and redesigning processes and workflows, because they infuse management discussions with the quantitative data needed for sound decision making. The Government Printing Office's use of a discrete-event simulation model helps illustrate the tool's potential to increase revenue, improve customer service, and optimize resource utilization in the area of telephone ordering. 相似文献
28.
29.
The problem of TEM wave propagation in a structure containing a medium exhibiting negative differential conductivity is solved. Some difficulties emerging from previous letters on the same argument are explained. 相似文献
30.