首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2684篇
  免费   190篇
  国内免费   3篇
电工技术   23篇
化学工业   586篇
金属工艺   72篇
机械仪表   98篇
建筑科学   92篇
矿业工程   10篇
能源动力   132篇
轻工业   460篇
水利工程   10篇
石油天然气   20篇
无线电   423篇
一般工业技术   462篇
冶金工业   58篇
原子能技术   20篇
自动化技术   411篇
  2024年   14篇
  2023年   46篇
  2022年   43篇
  2021年   123篇
  2020年   91篇
  2019年   88篇
  2018年   153篇
  2017年   108篇
  2016年   138篇
  2015年   113篇
  2014年   129篇
  2013年   477篇
  2012年   104篇
  2011年   110篇
  2010年   129篇
  2009年   141篇
  2008年   70篇
  2007年   56篇
  2006年   52篇
  2005年   29篇
  2004年   21篇
  2003年   17篇
  2002年   22篇
  2001年   79篇
  2000年   79篇
  1999年   78篇
  1998年   84篇
  1997年   81篇
  1996年   25篇
  1995年   10篇
  1994年   15篇
  1993年   14篇
  1992年   11篇
  1991年   6篇
  1990年   7篇
  1989年   8篇
  1988年   7篇
  1985年   7篇
  1984年   11篇
  1982年   6篇
  1981年   9篇
  1980年   8篇
  1979年   6篇
  1978年   8篇
  1977年   4篇
  1976年   6篇
  1975年   4篇
  1973年   5篇
  1971年   4篇
  1968年   4篇
排序方式: 共有2877条查询结果,搜索用时 15 毫秒
991.
992.
Purpose: Digitoxin is a cardiac glycoside used in the treatment of heart failure. Inspired by its known anti-inflammatory effect, this study aims to investigate the effect of digoxin in a sepsis model and to bring to light its effect and underlying mechanism in acute lung injury (ALI). Method: 28 wistar albino rats were divided into 4 groups. Sepsis model is performed by the feces intraperitoneal-injection procedure (FIP). Results: TNF-a, CRP, IL-6, IL 1-Beta, lactic acid, and MDA values were significantly decreased in the FIP+digitoxin group compared to the FIP+Saline group. When the same groups were examined, histological improvements such as decrease in alveolar inflammation and decrease in septal thickening in the digitoxin group and thorax CT were found to be significantly higher in the Hounsfield unit digitoxin group compared to the Saline group. Conclusion: Digitoxin has shown biochemical improvement in sepsis with all known mechanisms of action, and healing effects in both computerized tomography and histology in the lung.  相似文献   
993.
NADIRE ÖZENVER  THOMAS EFFERTH 《Biocell》2022,46(10):2151-2157
Carnosic acid (CA) is a natural phenolic diterpene mainly occurring in some species of the Lamiaceae family.Numerous studies described the cytotoxicity of CA towards different types of cancer both in vitro and in vivo. Particularly,the influence of CA in combination with other drugs, vitamins or natural products through affecting various targets hasraised interest. Current experimental in vivo data suggested that CA may cooperate with clinically used anticancer drugspromoting their activity against cancer. From this point of view, CA gained importance, because it may alterpharmacodynamic profiles of various agents in the case of their co-administration, and thereby, act in a potentiallysynergistic manner, which can provide a basis for potential applications of CA in the management of cancer. In thepresent review, we give an overview of CA as well as CA co-treatment regimens with a special focus on cancer. In thiscontext, the role of CA as an adjuvant treatment alternative is highlighted.  相似文献   
994.
An extract of polyphenols was obtained from organic red grape pomace, chemically analyzed, and used for functionalization of two bioactive glasses and porous hydroxyapatite. Functionalization is effective on hydroxyapatite and the bioactive glass with higher surface reactivity with a different grafting mechanism. Grafting does not inhibit redox and radical scavenging activity of polyphenols. The grafted polyphenols make a continuous layer with an almost complete surface coverage. Polyphenols are released with different kinetics according to the mechanism of grafting and maintain their redox activity. A homogeneous thin layer of polyphenols is still firmly grafted on both substrates after 28 days of soaking and it still maintains radical scavenging activity. The functionalized samples can be sterilized by gamma irradiation.  相似文献   
995.
996.
This paper examines the impact of inulin, Lactobacillus spp. (candidate probiotics), and synbiotic (inulin + Lactobacillus spp.) preparation on oxalate degrading activity and viability of Escherichia coli. In this study, the lowest viability of E. coli was recorded for the synbiotic treatments of Lactobacillus fermentum BP5 (59%) and IP5 (60%). The oxalate degrading activity of L. fermentum IP5 was 38.18 and 29.60% higher than the other strains after growth in 10 mM and 20 mM MRS-ox plus 5% inulin media, respectively. The mixture of three strains demonstrated higher oxalate degrading capacity than the individual strains and showed the same good growth rates (9.43 CFU mL−1) as individuals. The study concludes that the addition of prebiotics has a significant effect on probiotics; therefore, a combination of L. fermentum IP5 with inulin could be a viable probiotic-based functional food approach in administering oxalate metabolism and also treatment of E. coli-related infections.  相似文献   
997.
Food Science and Biotechnology - In this study, the effects of spray drying parameters as feed soluble solid content, inlet air temperature and outlet air temperature on spray drying of soapwort...  相似文献   
998.
Mobile Networks and Applications - Textile production industry is one of the biggest industries available and it is known by its negative effects to the environment. Greenhouse gas emissions can...  相似文献   
999.
Turgut  Özgün  Taube  Florian  Minner  Stefan 《OR Spectrum》2018,40(4):945-968
OR Spectrum - The backroom effect (BRE) constitutes the handling effort of a replenishment that does not fit on the shelf of a retailer. This effect needs to be included in the decision making of...  相似文献   
1000.
The paper reports solution treatment (ST) and mechanical alloying (MA) effects on the structure and static/dynamic mechanical behaviour of PM-MA’ed FeMnSiCrNi shape memory alloys associated with the formation of thermally and stress-induced martensite. The specimens were subjected to tensile pre-straining, in order to stress induce martensite and their gauges were cut and prepared for X-ray diffraction (XRD) as well as for optical and scanning electron microscopy (SEM). XRD patterns allowed determining the presence of large amounts of α′-body centred cubic (bcc) besides ε-hexagonal close packed (hcp) martensite and γ-face centred cubic (fcc) austenite. The decrease in the amount of α′-bcc at specimens ST’ed at 1273 and 1373?K, with increasing pre-straining degree, was confirmed by XRD patterns and SEM micrographs. Dynamic mechanical analysis (DMA) was performed by strain sweeps (SS). The SS-DMA graphs displayed storage modulus plateaux which were associated with the formation of ε-hcp martensite.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号