全文获取类型
收费全文 | 3708篇 |
免费 | 258篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 13篇 |
综合类 | 2篇 |
化学工业 | 1600篇 |
金属工艺 | 70篇 |
机械仪表 | 59篇 |
建筑科学 | 88篇 |
矿业工程 | 6篇 |
能源动力 | 83篇 |
轻工业 | 686篇 |
水利工程 | 17篇 |
石油天然气 | 37篇 |
无线电 | 137篇 |
一般工业技术 | 561篇 |
冶金工业 | 158篇 |
原子能技术 | 16篇 |
自动化技术 | 434篇 |
出版年
2024年 | 6篇 |
2023年 | 75篇 |
2022年 | 410篇 |
2021年 | 360篇 |
2020年 | 128篇 |
2019年 | 127篇 |
2018年 | 146篇 |
2017年 | 155篇 |
2016年 | 147篇 |
2015年 | 109篇 |
2014年 | 158篇 |
2013年 | 216篇 |
2012年 | 233篇 |
2011年 | 242篇 |
2010年 | 178篇 |
2009年 | 185篇 |
2008年 | 176篇 |
2007年 | 147篇 |
2006年 | 118篇 |
2005年 | 98篇 |
2004年 | 77篇 |
2003年 | 63篇 |
2002年 | 61篇 |
2001年 | 36篇 |
2000年 | 32篇 |
1999年 | 35篇 |
1998年 | 35篇 |
1997年 | 30篇 |
1996年 | 27篇 |
1995年 | 22篇 |
1994年 | 13篇 |
1993年 | 17篇 |
1992年 | 8篇 |
1991年 | 13篇 |
1990年 | 6篇 |
1989年 | 7篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 8篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1979年 | 6篇 |
1978年 | 3篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1971年 | 6篇 |
1969年 | 2篇 |
1964年 | 3篇 |
排序方式: 共有3967条查询结果,搜索用时 15 毫秒
1.
Chumakov Yu. A. Knyazeva A. G. Pribytkov G. A. 《Theoretical Foundations of Chemical Engineering》2021,55(3):490-503
Theoretical Foundations of Chemical Engineering - On the basis of the classic concepts of the theory of solid-phase combustion, for the first time, a model with a detailed scheme of chemical... 相似文献
2.
3.
Virginia Veronica Visconti Ida Cariati Simona Fittipaldi Riccardo Iundusi Elena Gasbarra Umberto Tarantino Annalisa Botta 《International journal of molecular sciences》2021,22(8)
DNA methylation is one of the most studied epigenetic mechanisms that play a pivotal role in regulating gene expression. The epigenetic component is strongly involved in aging-bone diseases, such as osteoporosis and osteoarthritis. Both are complex multi-factorial late-onset disorders that represent a globally widespread health problem, highlighting a crucial point of investigations in many scientific studies. In recent years, new findings on the role of DNA methylation in the pathogenesis of aging-bone diseases have emerged. The aim of this systematic review is to update knowledge in the field of DNA methylation associated with osteoporosis and osteoarthritis, focusing on the specific tissues involved in both pathological conditions. 相似文献
4.
Silicon - The products of solid-phase mechanochemical interaction between pyrocatechol and silicon dioxide yielding a powdered composite were studied using a number of physicochemical methods. This... 相似文献
5.
6.
7.
Antonio Mancini Carmine Bruno Edoardo Vergani Claudia dAbate Elena Giacchi Andrea Silvestrini 《International journal of molecular sciences》2021,22(4)
The pathophysiology of Polycystic Ovary Syndrome (PCOS) is quite complex and different mechanisms could contribute to hyperandrogenism and anovulation, which are the main features of the syndrome. Obesity and insulin-resistance are claimed as the principal factors contributing to the clinical presentation; in normal weight PCOS either, increased visceral adipose tissue has been described. However, their role is still debated, as debated are the biochemical markers linked to obesity per se. Oxidative stress (OS) and low-grade inflammation (LGI) have recently been a matter of researcher attention; they can influence each other in a reciprocal vicious cycle. In this review, we summarize the main mechanism of radical generation and the link with LGI. Furthermore, we discuss papers in favor or against the role of obesity as the first pathogenetic factor, and show how OS itself, on the contrary, can induce obesity and insulin resistance; in particular, the role of GH-IGF-1 axis is highlighted. Finally, the possible consequences on vitamin D synthesis and activation on the immune system are briefly discussed. This review intends to underline the key role of oxidative stress and low-grade inflammation in the physiopathology of PCOS, they can cause or worsen obesity, insulin-resistance, vitamin D deficiency, and immune dyscrasia, suggesting an inverse interaction to what is usually considered. 相似文献
8.
Iratxe Perez-Arnedo María J. Cantalejo Alba Martínez-Laorden Elena Gonzalez-Fandos 《International Journal of Food Science & Technology》2021,56(4):1855-1864
Microbiological contamination of chicken meat depends on the conditions under which the animals are reared, slaughtered and processed. The aim of this study was to determine the influence of farm origin and processing stages at slaughterhouse on the microbial safety and quality of chicken. Samples of chicken carcasses from three different farms were taken from a slaughterhouse. Mesophiles, Escherichia coli, coagulase positive Staphylococcci counts, presence of Listeria monocytogenes,Campylobacter and Salmonella were determined at five sampling points: after defeathering, after evisceration, after washing, after chilling and after cutting. Chilling reduced log numbers of mesophiles, coagulase positive Staphylococci and E. coli by 0.85, 1.52 and 2.2 log units, respectively. Salmonella was not detected after chilling. High prevalence of Campylobacter spp was observed at all the stages ranging between 84% and 100%. L. monocytogenes was not detected in chicken carcasses after defeathering. However, it was detected after evisceration and after washing and chilling. The most critical stage for L. monocytogenes contamination was the portioning operation, the prevalence in breast and legs being 88% and 84%, respectively. 相似文献
9.
Anna Enrico Wenjing Zhang Marie Lund Traulsen Elena Marzia Sala Paola Costamagna Peter Holtappels 《Journal of the European Ceramic Society》2018,38(7):2677-2686
Water-based sol-gel electrospinning is employed to manufacture perovskite oxide La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) nanofiber cathodes for intermediate-temperature solid oxide fuel cells. LSCF fibrous scaffolds are synthesized through electrospinning of a sol-gel solution employing water as the only solvent. Morphological characterizations demonstrate that the LSCF fibers have highly crystalline structure with uniform elemental distribution. After heat treatment, the average fiber diameter is 250 nm and the porosity of the nanofiber tissue is 37.5 %. The heat treated LSCF nanofibers are applied directly onto a Ce0.9Gd0.1O1.95 (CGO) electrolyte disk to form a symmetrical cell. Electrochemical characterization is carried out through electrochemical impedance spectroscopy (EIS) in the temperature range 550?°C–950?°C, and reproducibility of the electrochemical performance for a series of cells is demonstrated. At 650?°C, the average measured polarization resistance Rp is 1.0 Ω cm2. Measured performance decay is 1 % during the first 33?h of operation at 750?°C, followed by an additional 0.7 % over the subsequent 70?h. 相似文献