全文获取类型
收费全文 | 2206篇 |
免费 | 83篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 50篇 |
综合类 | 17篇 |
化学工业 | 382篇 |
金属工艺 | 28篇 |
机械仪表 | 39篇 |
建筑科学 | 93篇 |
矿业工程 | 5篇 |
能源动力 | 49篇 |
轻工业 | 159篇 |
水利工程 | 20篇 |
石油天然气 | 12篇 |
武器工业 | 3篇 |
无线电 | 302篇 |
一般工业技术 | 334篇 |
冶金工业 | 245篇 |
原子能技术 | 23篇 |
自动化技术 | 531篇 |
出版年
2023年 | 9篇 |
2021年 | 29篇 |
2020年 | 18篇 |
2019年 | 28篇 |
2018年 | 34篇 |
2017年 | 47篇 |
2016年 | 47篇 |
2015年 | 46篇 |
2014年 | 67篇 |
2013年 | 116篇 |
2012年 | 101篇 |
2011年 | 123篇 |
2010年 | 93篇 |
2009年 | 104篇 |
2008年 | 121篇 |
2007年 | 94篇 |
2006年 | 101篇 |
2005年 | 89篇 |
2004年 | 87篇 |
2003年 | 87篇 |
2002年 | 80篇 |
2001年 | 35篇 |
2000年 | 89篇 |
1999年 | 56篇 |
1998年 | 58篇 |
1997年 | 32篇 |
1996年 | 37篇 |
1995年 | 25篇 |
1994年 | 31篇 |
1993年 | 39篇 |
1992年 | 26篇 |
1991年 | 16篇 |
1990年 | 15篇 |
1989年 | 16篇 |
1988年 | 19篇 |
1987年 | 20篇 |
1986年 | 23篇 |
1985年 | 20篇 |
1984年 | 17篇 |
1983年 | 16篇 |
1982年 | 16篇 |
1981年 | 17篇 |
1980年 | 11篇 |
1979年 | 14篇 |
1978年 | 10篇 |
1977年 | 12篇 |
1976年 | 20篇 |
1975年 | 12篇 |
1973年 | 13篇 |
1972年 | 9篇 |
排序方式: 共有2292条查询结果,搜索用时 31 毫秒
1.
Macintosh Katrina A. McDowell Richard W. Wright-Stow Aslan E. Depree Craig Robinson Guy M. 《Nutrient Cycling in Agroecosystems》2021,120(2):121-129
Nutrient Cycling in Agroecosystems - Reducing agriculturally derived diffuse contaminant losses (via non-point sources) from land to water has proven difficult for decades. Owing to the diversity... 相似文献
2.
Recently, new type of small Base Station known as “femtocell” has emerged. Femtocells are deployed by customers with minimal or no radio frequency planning in arbitrary locations. Thus, operators must use new approaches rather than the classic network planning and optimization. Self‐organization techniques will allow femtocells to integrate themselves into the network, learn about their environment, and adjust their parameters (power, frequency) accordingly. In this paper, a new spectrum mobility management algorithm is proposed. It allows intelligent use of the spectrum by secondary user (femtocell guest user) accessing spectrum holes unoccupied by primary users (subscriber user) and handing over to new channels or femtocells when primary user appears. Our solution aims to have more adaptive and aware communication system, which can make better use of available natural resources. 相似文献
3.
4.
Melissa Assad-Bustillos Juliette Palier Hanitra Rabesona Yvan Choiset Guy Della Valle Gilles Feron 《Journal of texture studies》2020,51(1):134-143
This study investigated the digestibility of proteins in a pea protein-fortified sponge cake, as well as the impact of the degree of structure of the bolus produced by elderly subjects on the digestibility of proteins by combining ex vivo and in vitro approaches via the standardized protocol INFOGEST. The sponge cakes were consumed by a group of 20 elderly subjects with contrasting physiology, their boli were recovered just before swallowing, and their apparent viscosity was measured to delineate the bolus degree of structure. According to this criterion, two pools were formed with boli from subjects selected at the extremes: low viscosity and high viscosity, with apparent viscosity values (at 120 s−1) of 124 ± 18 and 208 ± 19 Pa s, respectively. The sponge cakes and the two pools underwent in vitro digestion. Protein hydrolysis kinetics was followed by measuring the released primary amino groups (NH2) and by sodium-dodecyl-sulfate polyacrylamide gel electrophoresis at different time points. For all samples, the representative bands of pea proteins disappear gradually during digestion, accompanied by the appearance of bands indicating the presence of proteins with MW < 15 kDa. In addition, the NH2 concentrations increase over time and do not differ between sponge cake and pea protein isolate. Moreover, the degree of structure of the food bolus has no significant effect on the concentration of NH2 released. These results showed that pea proteins in a fortified sponge cake are bioaccessible under standardized conditions and that the degree of structure of the bolus did not influence protein digestibility for these foods. 相似文献
5.
6.
7.
Nielsen Guillaume Janin Amelie Coudert Lucie Blais Jean Francois Mercier Guy 《Mine Water and the Environment》2018,37(1):42-55
Mine Water and the Environment - Passive treatment is a promising, green technology that is increasingly being used for mine drainage treatment. However, several challenges remain concerning its... 相似文献
8.
Barbara Walther Aaron M. Lett Alessandra Bordoni Lidia Toms‐Cobos Juan Antonio Nieto Didier Dupont Francesca Danesi Danit R. Shahar Ana Echaniz Roberta Re Aida Sainz Fernandez Amlie Deglaire Doreen Gille Alexandra Schmid Guy Vergres 《Molecular nutrition & food research》2019,63(21)
Nutritional research is currently entering the field of personalized nutrition, to a large extent driven by major technological breakthroughs in analytical sciences and biocomputing. An efficient launching of the personalized approach depends on the ability of researchers to comprehensively monitor and characterize interindividual variability in the activity of the human gastrointestinal tract. This information is currently not available in such a form. This review therefore aims at identifying and discussing published data, providing evidence on interindividual variability in the processing of the major nutrients, i.e., protein, fat, carbohydrates, vitamins, and minerals, along the gastrointestinal tract, including oral processing, intestinal digestion, and absorption. Although interindividual variability is not a primary endpoint of most studies identified, a significant number of publications provides a wealth of information on this topic for each category of nutrients. This knowledge remains fragmented, however, and understanding the clinical relevance of most of the interindividual responses to food ingestion described in this review remains unclear. In that regard, this review has identified a gap and sets the base for future research addressing the issue of the interindividual variability in the response of the human organism to the ingestion of foods. 相似文献
9.
10.
Graded evolution of anisotropic microstructure during sintering from crystal-oriented powder compact
Shoko Baba Alexandre Maître Nicolas Pradeilles Guy Antou Nobuo Saito Satoshi Tanaka 《International Journal of Applied Ceramic Technology》2020,17(2):677-684
Anisotropic sintering, including shrinkage and grain growth, was examined for c-axis-oriented (Sr,Ca)2NaNb5O15 (SCNN) ceramics, which were prepared by colloidal processing under a magnetic field. In the c-axis-oriented SCNN powder compact, shrinkage and grain growth along the c-axis were higher than those along the a-axis. The anisotropic microstructural development was clearly associated with anisotropic sintering shrinkage. X-ray diffraction, scanning electron microscopy, and energy back scattering diffraction showed that the grain growth of oriented particles by including random grains contribute to the development of the oriented microstructure. Finally, the highly crystal-oriented SCNN ceramics with a densified microstructure were obtained through anisotropic sintering. These results clearly showed the potential to develop a well-defined anisotropic microstructure during sintering by designing and controlling the particle packing structure in a powder compact. 相似文献