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   2662篇
  免费   147篇
  国内免费   11篇
电工技术   35篇
化学工业   684篇
金属工艺   65篇
机械仪表   86篇
建筑科学   83篇
矿业工程   23篇
能源动力   85篇
轻工业   190篇
水利工程   18篇
石油天然气   19篇
武器工业   1篇
无线电   211篇
一般工业技术   548篇
冶金工业   236篇
原子能技术   39篇
自动化技术   497篇
  2023年   26篇
  2022年   40篇
  2021年   94篇
  2020年   90篇
  2019年   68篇
  2018年   106篇
  2017年   112篇
  2016年   104篇
  2015年   96篇
  2014年   124篇
  2013年   209篇
  2012年   157篇
  2011年   184篇
  2010年   136篇
  2009年   125篇
  2008年   135篇
  2007年   109篇
  2006年   89篇
  2005年   82篇
  2004年   65篇
  2003年   62篇
  2002年   49篇
  2001年   33篇
  2000年   26篇
  1999年   21篇
  1998年   34篇
  1997年   23篇
  1996年   20篇
  1995年   27篇
  1994年   26篇
  1993年   23篇
  1992年   15篇
  1991年   16篇
  1990年   12篇
  1989年   13篇
  1988年   17篇
  1987年   28篇
  1986年   16篇
  1985年   26篇
  1984年   18篇
  1983年   11篇
  1982年   18篇
  1981年   9篇
  1980年   9篇
  1979年   14篇
  1977年   8篇
  1976年   8篇
  1975年   10篇
  1973年   12篇
  1972年   9篇
排序方式: 共有2820条查询结果,搜索用时 15 毫秒
1.
Journal of Applied Electrochemistry - Organic corrosion inhibitors have become competent alternatives to hazardous chrome conversion coatings due to their rapid adsorption over metal surfaces in...  相似文献   
2.
This paper is devoted to microscopic methods for the identification of sulfate-reducing bacteria (SRB). In this context, it describes various habitats, morphology and techniques used for the detection and identification of this very heterogeneous group of anaerobic microorganisms. SRB are present in almost every habitat on Earth, including freshwater and marine water, soils, sediments or animals. In the oil, water and gas industries, they can cause considerable economic losses due to their hydrogen sulfide production; in periodontal lesions and the colon of humans, they can cause health complications. Although the role of these bacteria in inflammatory bowel diseases is not entirely known yet, their presence is increased in patients and produced hydrogen sulfide has a cytotoxic effect. For these reasons, methods for the detection of these microorganisms were described. Apart from selected molecular techniques, including metagenomics, fluorescence microscopy was one of the applied methods. Especially fluorescence in situ hybridization (FISH) in various modifications was described. This method enables visual identification of SRB, determining their abundance and spatial distribution in environmental biofilms and gut samples.  相似文献   
3.
In the Industry 4.0 era, the chemical industry is embracing broad adoption of artificial intelligence (AI) and machine learning (ML) methods. This article provides a holistic view of how the industry is transforming digitally towards AI at scale. First, a historical perspective on how the industry used AI to aid humans in better decision-making is shown. Then state-of-the-art AI research addressing industrial needs on reliability and safety, process optimization, supply chain, material discovery, and reaction engineering is highlighted. Finally, a vision of the plant of the future is illustrated with critical components of AI-ready culture, model life cycle management, and renewed role of humans in chemical manufacturing.  相似文献   
4.
A systematic, diversity-oriented synthesis approach was employed to access a natural product-inspired flavonoid library with diverse chemical features, including chemical properties, scaffold, stereochemistry, and appendages. Using Cell Painting, the effects of these diversity elements were evaluated, and multiple chemical features that predict biological performance diversity were identified. Scaffold identity appears to be the dominant predictor of performance diversity, but stereochemistry and appendages also contribute to a lesser degree. In addition, the diversity of chemical properties contributed to performance diversity, and the driving chemical property was dependent on the scaffold. These results highlight the importance of key chemical features that may inform the creation of small-molecule, performance-diverse libraries to improve the efficiency and success of high-throughput screening campaigns.  相似文献   
5.
6.
Pavić  Ivan  Džapo  Hrvoje 《Real-Time Systems》2020,56(1):112-119
Real-Time Systems - In this paper we point to some errors in recent paper by Asyaban et al. in which they devise an exact schedulability test. These errors are critical for the correct operation of...  相似文献   
7.
8.
The preparation of poly(hexylacrylate)core‐poly(ethyleneglycol methacrylate)shell (PHA‐co‐PEGMA) nanogels, to be used as fillers in nanocomposite hydrogels, is reported. Stable nanogels with particle sizes between 90–300 nm were obtained varying the conditions of synthesis. The synthesis recipe of the nanogels could be easily scaled up. Purified and dispersed nanogels in aqueous solution were used as soft fillers for poly(2‐hydroxyethyl methacrylate) (PHEMA) hydrogels, crosslinked with ethylene glycol dimethacrylate (EGDMA). The obtained nanocomposite hydrogels exhibit a larger swelling capacity and a higher thermal stability in comparison with the non‐filled PHEMA hydrogels. Young, storage, and lost moduli, increase largely, in the better case up to 72.5% in the swollen state; while in the dry state the storage modulus increase up to 4.7 fold with a very low load on nanogels (0.64 wt%); resulting in biomaterials with improved properties with potential applications in medical devices. POLYM. ENG. SCI., 59:170–181, 2019. © 2018 Society of Plastics Engineers  相似文献   
9.
We report the results of magnetic, thermodynamic, transport and magnetocaloric effect (MCE) studies of newly synthesized Gd_(10)Co_(20)Si_(70) alloy. These measurements confirm an antiferromagnetic transition at T_N=9 K. Both MCE and magnetoresistance (MR) show quadratic dependence on the applied magnetic field, indicating the presence of spin fluctuations in the alloy. The maximum values of the magnetic entropy change determined from the isothermal magnetization data for magnetic field change of 7 and9 T are found to be 10.5 and 15.6 J/kg·K, respectively. As a consequence of the spin fluctuations effect, the MCE peaks are pulled towards high temperature side as asymmetrically broadened peak. The MR attains a large positive value of 73%at 2 K in 8 T. The large MR and reversible MCE make this alloy an attractive multifunctional magnetic material.  相似文献   
10.
Hydrophilic polymer networks (hydrogels) based on sodium carboxymethylcellulose (NaCMC) and polycarboxylic acids (oxalic, succinic, citric and adipic) as cross-linking agents are synthesized by esterification reaction; one series of NaCMC hydrogels cross-linked with citric acid is prepared with acrylamide and acrylic acid (Aam/Aac) copolymers using the design of semi-interpenetrating polymer networks (semi-IPN), in order to increase their potential application for flocculation purposes. The Infrared spectroscopy (FTIR) of hydrogels confirms the esterification reaction between NaCMC and cross-linking agents. Results of swelling measurements show that citric acid in the amount of 15 wt% gives the hydrogels with the best absorption capacity. The results of Differential scanning calorimetry (DSC) and Thermal gravimetric analysis (TGA) show no significant difference in thermal properties of neat and semi-interpenetrating NaCMC hydrogels. The amorphous nature of hydrogels is confirmed by X-ray diffraction analysis (XRD). The results of flocculation study show that combination of NaCMC network and Aam/Aac copolymer with initial mass ratio of 10/90 creates a theoretical platform for the production of flocculant which could show high efficacy in purifying of water dominated by positively charged particles.  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