全文获取类型
收费全文 | 2912篇 |
免费 | 229篇 |
国内免费 | 21篇 |
专业分类
电工技术 | 68篇 |
综合类 | 15篇 |
化学工业 | 625篇 |
金属工艺 | 70篇 |
机械仪表 | 120篇 |
建筑科学 | 147篇 |
矿业工程 | 10篇 |
能源动力 | 207篇 |
轻工业 | 281篇 |
水利工程 | 50篇 |
石油天然气 | 36篇 |
无线电 | 294篇 |
一般工业技术 | 530篇 |
冶金工业 | 75篇 |
原子能技术 | 18篇 |
自动化技术 | 616篇 |
出版年
2024年 | 11篇 |
2023年 | 73篇 |
2022年 | 104篇 |
2021年 | 212篇 |
2020年 | 169篇 |
2019年 | 175篇 |
2018年 | 258篇 |
2017年 | 215篇 |
2016年 | 212篇 |
2015年 | 128篇 |
2014年 | 198篇 |
2013年 | 358篇 |
2012年 | 171篇 |
2011年 | 177篇 |
2010年 | 127篇 |
2009年 | 100篇 |
2008年 | 70篇 |
2007年 | 68篇 |
2006年 | 48篇 |
2005年 | 24篇 |
2004年 | 32篇 |
2003年 | 29篇 |
2002年 | 19篇 |
2001年 | 15篇 |
2000年 | 18篇 |
1999年 | 17篇 |
1998年 | 18篇 |
1997年 | 22篇 |
1996年 | 16篇 |
1995年 | 7篇 |
1994年 | 10篇 |
1993年 | 9篇 |
1992年 | 3篇 |
1991年 | 6篇 |
1990年 | 2篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 6篇 |
1984年 | 2篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1979年 | 2篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有3162条查询结果,搜索用时 15 毫秒
1.
Tourajizadeh Hami Yousefzadeh Mahdi Khalaji Ali Keymasi Bamdad Mahdi 《International Journal of Control, Automation and Systems》2022,20(5):1671-1681
International Journal of Control, Automation and Systems - In this paper, a new controllable simulator is proposed and modeled by which, experimental tests of the aircraft’s models can be... 相似文献
2.
Niccolò Renoldi Seyed Hadi Peighambardoust Donatella Peressini 《International Journal of Food Science & Technology》2021,56(7):3235-3244
In this work, corn extruded snack products were enriched with rice bran (RB) at 10% and 15%. A co-rotating twin-screw extruder was used with a feed moisture content of 16 g 100 g−1, a screw speed of 240 r.p.m. and four heating sections of the barrel (100, 140, 150 and 150 °C). The impact of RB inclusion on nutritional profile, starch digestion, physicochemical and textural properties of snack products was evaluated. RB-enriched extrudates showed a lower specific volume and hardness and higher crispness than control. RB at 15% gave a water-holding capacity lower than control. Rheology of extrudate dispersions indicated an increase in elastic interactions and solid-like behaviour with RB supplementation. Differences in rheological properties resulted in attenuation of predictive glycaemic response for RB-enriched snacks. 相似文献
3.
4.
5.
The mechanical integrity of battery separators is critical for battery safety and durability. A comprehensive study of strain‐rate‐dependent tensile and puncture properties of a polypropylene lithium‐ion battery separator is presented here with a new model. Due to anisotropy of the polymeric membrane, tensile testing was conducted for different directions. Results showed that tensile strength and elastic modulus were increased 1000% and 500%, respectively, for different directions. It was also demonstrated that tensile strength changed 10 to 25% with strain rate (1.67 × 10?4 to 1.67 × 10?1 s?1) for different directions. An equation was obtained for the first time for flow stress versus strain rate at varied tensile directions with respect to machine direction. Moreover, puncture testing was performed and it was shown that puncture strength was increased 140% with increasing strain rate from 0.25 to 250 mm min?1. Two failure modes were also observed in puncture samples. Finally, Eyring's model was used to calculate activation enthalpy of the porous polypropylene separator. © 2020 Society of Chemical Industry 相似文献
6.
Maktabdar Oghaz Mahdi Maarof Mohd Aizaini Rohani Mohd Foad Zainal Anazida Shaid Syed Zainudeen Mohd 《Neural computing & applications》2019,31(6):1835-1853
Neural Computing and Applications - Texture analysis is devised to address the weakness of color-based image segmentation models by considering the statistical and spatial relations among the group... 相似文献
7.
The Journal of Supercomputing - Data center network virtualization is being considered as a promising technology to provide a performance guarantee for cloud computing applications. One important... 相似文献
8.
9.
DJ Conway MJ Holland RL Bailey AE Campbell OS Mahdi R Jennings E Mbena DC Mabey 《Canadian Metallurgical Quarterly》1997,65(3):1003-1006
Tumor necrosis factor alpha (TNF-alpha) may play a central role in the disease pathogenesis which occurs as a consequence of chlamydial infection. To investigate the importance of TNF-alpha gene promoter polymorphisms and TNF-alpha levels in tear fluid in scarring trachoma, a large matched-pair case-control study was performed in The Gambia. The -308A allele was present in a higher proportion of patients (28.4%) than controls (18.4%), with an increasing association for homozygotes (chi2 for trend, P = 0.032; allele frequency, 0.163 in patients and 0.099 in controls; chi2, P = 0.025). For the -238A allele, the association was similar but not significant. The disease association was highly significant when the number of either -308A or -238A sites in an individual was considered (P = 0.003). TNF-alpha promoter alleles are tightly linked to some HLA class I and II alleles, but multivariate analysis confirmed that the disease associations were independent of HLA, although a class I allele, A*6802, is also associated with disease. TNF-alpha was more frequently detected in tear samples from patients (27.6%) than from controls (15.9%), increasingly so for higher levels of detectable TNF-alpha (P = 0.015). Among patients, detectable TNF-alpha in tears was highly associated with the presence of ocular chlamydial infection (P < 0.001). The results indicate that TNF-alpha plays a major role in the tissue damage and scarring which occurs as a consequence of Chlamydia trachomatis infection. 相似文献
10.
Adnan Köksal 《Journal of Infrared, Millimeter and Terahertz Waves》1997,18(8):1525-1537
A parametric study of linearly tapered slot antenna (LTSA) in air and a method for optimization of its pattern are presented. A method of moments code is utilized to investigate the behavior of LTSA’s as the length, height and the taper angle varies. It is shown that the antenna pattern can be improved using a top layer of dielectric material with varying permittivity. 相似文献