全文获取类型
收费全文 | 1723篇 |
免费 | 66篇 |
国内免费 | 11篇 |
专业分类
电工技术 | 71篇 |
综合类 | 2篇 |
化学工业 | 316篇 |
金属工艺 | 34篇 |
机械仪表 | 39篇 |
建筑科学 | 32篇 |
矿业工程 | 1篇 |
能源动力 | 141篇 |
轻工业 | 135篇 |
水利工程 | 13篇 |
石油天然气 | 13篇 |
武器工业 | 1篇 |
无线电 | 174篇 |
一般工业技术 | 332篇 |
冶金工业 | 198篇 |
原子能技术 | 11篇 |
自动化技术 | 287篇 |
出版年
2023年 | 27篇 |
2022年 | 59篇 |
2021年 | 97篇 |
2020年 | 56篇 |
2019年 | 70篇 |
2018年 | 84篇 |
2017年 | 60篇 |
2016年 | 67篇 |
2015年 | 41篇 |
2014年 | 54篇 |
2013年 | 118篇 |
2012年 | 59篇 |
2011年 | 84篇 |
2010年 | 55篇 |
2009年 | 62篇 |
2008年 | 58篇 |
2007年 | 54篇 |
2006年 | 33篇 |
2005年 | 25篇 |
2004年 | 38篇 |
2003年 | 27篇 |
2002年 | 24篇 |
2001年 | 21篇 |
2000年 | 23篇 |
1999年 | 19篇 |
1998年 | 63篇 |
1997年 | 39篇 |
1996年 | 37篇 |
1995年 | 27篇 |
1994年 | 32篇 |
1993年 | 24篇 |
1992年 | 14篇 |
1991年 | 30篇 |
1990年 | 26篇 |
1989年 | 25篇 |
1988年 | 18篇 |
1987年 | 13篇 |
1986年 | 11篇 |
1985年 | 12篇 |
1984年 | 12篇 |
1983年 | 13篇 |
1982年 | 12篇 |
1981年 | 10篇 |
1979年 | 9篇 |
1978年 | 9篇 |
1976年 | 6篇 |
1973年 | 4篇 |
1972年 | 7篇 |
1968年 | 3篇 |
1966年 | 4篇 |
排序方式: 共有1800条查询结果,搜索用时 15 毫秒
951.
With increase in the socioeconomic status, the demand of the health and nutraceutical food is increasing day-by-day. Wine contains a wide variety of the biologically active compounds including antimicrobial compounds (phenolics, acids, alcohols, bioamines, etc.) which possess the numerous health benefits. The concentration of these compounds changes according to the raw material their varieties and vinification process. Phenolics, such as epicatechin, gallic acid, catechin, caffeic acid, vannillic acid, p-coumaric acid and resveratrol, are present in different wines. Wine also contains various acids such as tartaric acid, succinic acid, acetic acid and malic acid. Alcohol includes majorly the ethanol with a minute quantity of methanol and other higher alcohols, whereas the bioamine includes the ethanolamine, ammonia and histamine. These all compounds have the ability to possess antimicrobial activity either independently or in the conjugative form with the other compounds. In this article, efforts have been made to document the different antimicrobial compounds present in wines and their antimicrobial activity. This review has the potential to attract readers; mainly researchers and industrialists for the future study and product development in the wine industry. 相似文献
952.
Bio-based polyurethane (PU) foams were developed from bio-polyol (castor oil-based) in the presence of selective catalyst, surfactant, and blowing agent. Bentonite nanoclay (NC) was incorporated into the bio-polyol mixture as nano-reinforcement, while, triethyl phosphate was used as flame-retardant agent. After fabrication, these bioengineered foam nano-composites were studied for microstructural, mechanical and thermal characterizations. Fourier transform infrared spectroscopy analysis indicated the presence of characteristic functionalities within biopolyol segments, which was influenced by reactant activity within the polyurethane (PU) foams. Scanning electron microscopy revealed the cellular morphology of the foam. Thermogravimetric analysis enabled the study of foam decomposition behavior for different sample compositions. Incorporation of NC into pristine foam was found to delay the onset degradation temperature. Flammability studies depicted significant enhancement of flame retardancy with incorporation of NC up to a certain loading level. Compression tests demonstrated that significant improvement of compressive strength properties of foams could be achieved by incorporating bentonite nanoclay, owing to nucleation effect of nanoclay and corresponding enhanced structural integrity. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47063. 相似文献
953.
Qayyum Abdul Saeed Malik Aamir Saad Naufal M. Iqbal Mahboob Abdullah Mohd Faris Rasheed Waqas Abdullah Tuan A. B. Rashid Bin Jafaar Mohd Yaqoob 《Neural computing & applications》2019,31(8):3587-3607
Neural Computing and Applications - This work offers an approach to aerial image classification for use in remote sensing object recognition, image processing and computer vision. Sparse coding... 相似文献
954.
Rohit Malik Hyun-Min Kim Young-Wook Kim Kwang Joo Kim 《Ceramics International》2018,44(14):16394-16399
SiC–BN composites were fabricated by conventional hot-pressing from β-SiC and h-BN nanopowders with 2?vol% yttria as a sintering additive. Electrical and thermal properties of the composites were investigated as a function of initial BN content. Owing to the nanosize of the starting powders, the grain-growth-assisted N-doping of the SiC lattice was significantly enhanced during liquid-phase sintering, yielding the highest-reported electrical conductivity of ~124 (Ω?cm)?1 for a SiC–4-vol% BN composite. The typical values of electrical resistivity and thermal conductivity of the SiC–4-vol% BN composite at room temperature were 8.1?×?10?3 Ω?cm and 92.4?W?m?1 K?1, respectively. 相似文献
955.
Mookambika RamyaBai Nicole M. Wedick Shobana Shanmugam Kokila Arumugam Lakshmipriya Nagarajan Kavitha Vasudevan Geetha Gunasekaran Gayathri Rajagopal Donna Spiegelman Vasanti Malik Ranjit Mohan Anjana Frank B. Hu Ranjit Unnikrishnan Walter Willett Nagappa Malleshi Marina A. Njelekela Dorothy Gimbi Kamala Krishnaswamy CJK Henry Viswanathan Mohan Vasudevan Sudha 《Journal of food science》2019,84(12):3373-3382
956.
957.
958.
Harish V Dixit Aviraj R Jadhav Yogesh M Jain Alice N Cheeran Vikas N Gupta P K Sharma 《Sadhana》2018,43(3):33
At high average power level, waveguide-based structures are indispensable in microwave systems due to their higher power handling capacity. These structures are often used to perform power division and combination operation. Folded H plane tee is one of the many components that can be used for the power division application. Its advantage is that the output arms and input arms are in a single plane along a single axis, thus taking less space in the overall system. However, their proper thermal management is indispensable for its use, as high surface temperature of the waveguide reduces its power handling capacity at high power level. This paper presents quick, easy design steps and methodology for obtaining the structure of a folded H plane tee at any given frequency of operation. Further, a scheme for the thermal management for high input power level (500 kW continuous wave) is presented. The proposed methodology is tested at various frequencies in COMSOL Multiphysics, CST Microwave Studio and HFSS with excellent results. A prototype structure was fabricated for use at 3.7 GHz, which exhibited good agreement with the simulation results. 相似文献
959.
960.
Sheenam Garg Vaibhao Kisanrao Lule Ravinder Kumar Malik Sudhir Kumar Tomar 《International Journal of Food Properties》2016,19(11):2550-2574
Functional foods are the focus of attraction for well-being. The healthy living of Asians may be attributed to a diet enriched with soy isoflavones viz. genistein and daidzein which fills the gap of proteinaceous diet in vegetarians. Several factors, such as administration, dosage, metabolism, ingestion of other pharmacological substances, type of estrogen receptors, and presence or absence of endogenous estrogen, affect the activities and bioavailability of isoflavones. The mode of therapeutic action could be either through the stimulation of estrogen receptors or by the non-involvement of estrogen receptors. Soy, due to its isoflavones content, serves as a balanced and remedial substitute in combating various lifestyle disorders, like cancer prevention, by interruption of the breakdown of extracellular matrix that surrounds growing vessels and tumors, lowering of lipid and blood insulin levels by regulating lipid and glucose metabolism, alleviation of menopausal symptoms, and osteoprotective effects by modulating estrogen receptors, thus acting as a safer switch to hormone replacement therapy, anti-hypertensive effect which may also contribute to cardioprotective, anti-oxidative effect, regulation of cognitive functions, and many others. Therefore, it could be regarded as a valuable therapeutics. However, since soy isoflavones also act as endocrine disruptors, they also possess some negative effects. Concerns have been raised in relation to thyroid function abnormality. In view of the previously mentioned facts an attempt has been made to review the literature available on both beneficial as well as deleterious role of isoflavones, soy derived bioactive compounds. 相似文献