全文获取类型
收费全文 | 287821篇 |
免费 | 79963篇 |
国内免费 | 53212篇 |
专业分类
电工技术 | 36504篇 |
技术理论 | 2篇 |
综合类 | 32023篇 |
化学工业 | 38178篇 |
金属工艺 | 31081篇 |
机械仪表 | 13380篇 |
建筑科学 | 20251篇 |
矿业工程 | 16333篇 |
能源动力 | 10794篇 |
轻工业 | 32463篇 |
水利工程 | 10348篇 |
石油天然气 | 15942篇 |
武器工业 | 4756篇 |
无线电 | 40957篇 |
一般工业技术 | 38826篇 |
冶金工业 | 10319篇 |
原子能技术 | 3061篇 |
自动化技术 | 65778篇 |
出版年
2024年 | 2941篇 |
2023年 | 6004篇 |
2022年 | 8687篇 |
2021年 | 10699篇 |
2020年 | 12172篇 |
2019年 | 20153篇 |
2018年 | 21617篇 |
2017年 | 23329篇 |
2016年 | 22795篇 |
2015年 | 23402篇 |
2014年 | 23555篇 |
2013年 | 23699篇 |
2012年 | 24543篇 |
2011年 | 21701篇 |
2010年 | 20181篇 |
2009年 | 16990篇 |
2008年 | 15119篇 |
2007年 | 14306篇 |
2006年 | 12342篇 |
2005年 | 10585篇 |
2004年 | 11853篇 |
2003年 | 9502篇 |
2002年 | 9244篇 |
2001年 | 8046篇 |
2000年 | 6953篇 |
1999年 | 5690篇 |
1998年 | 4644篇 |
1997年 | 4034篇 |
1996年 | 3838篇 |
1995年 | 3817篇 |
1994年 | 3103篇 |
1993年 | 2830篇 |
1992年 | 2727篇 |
1991年 | 1997篇 |
1990年 | 1558篇 |
1989年 | 1460篇 |
1988年 | 1124篇 |
1987年 | 346篇 |
1986年 | 310篇 |
1985年 | 218篇 |
1984年 | 159篇 |
1982年 | 156篇 |
1981年 | 157篇 |
1980年 | 132篇 |
1978年 | 107篇 |
1976年 | 232篇 |
1975年 | 206篇 |
1972年 | 237篇 |
1971年 | 128篇 |
1960年 | 205篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Qiang Xia Tao Feng Xiaowei Lou Ying Wang Yangying Sun Daodong Pan Jinxuan Cao 《International Journal of Food Science & Technology》2020,55(2):669-680
As a decisive attribute, flavour could be influenced by HP treatments through multiple physical and chemical pathways within the high pressure (HP)-assisted meat curing process. This investigation aimed to identify the major pathway influencing volatile flavour patterns of two representative vinasse-cured duck (VCD) products with HP treatments (150–300 MPa/15 min), including wet and dry types, by employing headspace fingerprinting as an untargeted approach. Results suggested that HP treatments greatly lowered moisture contents and increased Warner-Bratzler shear force and thiobarbituric acid reactive substances of the cured samples. According to multivariate models, the volatile flavour patterns of the HP-processed VCD could be clearly separated from the unprocessed samples, but the VCD pressurised at different intensities represented similar volatile fingerprinting, which was validated by e-nose analysis. The discriminant analysis (OPLS-DA) model outlined vinasse-derived ethanol, acetic acid, 3-methyl-1-butanol, 2-methyl-1-butanol, phenethyl alcohol and 2-methyl-3-octanone as the major discriminant aromas across the unpressurised and pressurised samples. 相似文献
82.
The application of deep learning in the field of object detection has
experienced much progress. However, due to the domain shift problem, applying an
off-the-shelf detector to another domain leads to a significant performance drop. A
large number of ground truth labels are required when using another domain to train
models, demanding a large amount of human and financial resources. In order to avoid
excessive resource requirements and performance drop caused by domain shift, this
paper proposes a new domain adaptive approach to cross-domain vehicle detection. Our
approach improves the cross-domain vehicle detection model from image space and
feature space. We employ objectives of the generative adversarial network and cycle
consistency loss for image style transfer in image space. For feature space, we align
feature distributions between the source domain and the target domain to improve the
detection accuracy. Experiments are carried out using the method with two different
datasets, proving that this technique effectively improves the accuracy of vehicle
detection in the target domain. 相似文献
84.
全媒体技术的发展推动我们进入全媒体时代,在全媒体时代下,综艺晚会要以引领大众的审美潮流以及与观众保持较强的互动作为发展方向。总结了全媒体时代下综艺晚会的有效发展策略,包括精心策划、利用高科技等。 相似文献
85.
Wang Lu-di Zhou Wei Xing Ying Liu Na Movahedipour Mahmood Zhou Xiao-guang 《浙江大学学报:C卷英文版》2019,20(3):405-413
Frontiers of Information Technology & Electronic Engineering - Reconstruction of a 12-lead electrocardiogram (ECG) from a serial 3-lead ECG has been researched in the past to satisfy the need... 相似文献
86.
87.
88.
Although Mg alloy attracts great attention for engineering applications because of high specific strength and low density, low corrosion resistance limits its extensive use. In this study, Mg–Al–Zn–Mn alloy was treated via a laser cladding process to generate a dense and compact laser cladding layer with solid metallurgical bonding on the substrate for improving corrosion resistance, effectively hindering the corrosion pervasion into Mg alloy. The corrosion current density declined from 103 μA/cm2 for Mg alloy to 13 μA/cm2 for the laser cladding layer in NaCl aqueous solution. Moreover, the laser cladding layer was slightly corroded in comparison with Mg alloy in NaCl aqueous solution. Besides, the microhardness of the cladding layer reached a mean value of 170.5 HV, 3.1 times of Mg alloy (56.8 HV) due to the in situ formation of hardening intermetallic phases. Wear resistance of laser cladding layer was also obviously improved. These results demonstrated that the laser cladding layer obviously enhanced anticorrosion property of Mg alloy for engineering applications. 相似文献
89.
Although Mg alloy possesses high specific strength, low density, and good biocompatibility, poor corrosion resistance hinders its further applications. In the present study, an innovative protective layer against corrosion was prepared on the AZ31 Mg alloy via alkali pretreatment followed by vanillic acid treatment. The alkali pretreatment supplied –OH for the AZ31 Mg alloy surface to react with vanillic acid. The vanillic acid treatment played a crucial role in enhancing the corrosion resistance due to the excellent ability to act as a barrier and retard aqueous solution penetration, which effectively isolated the underlying Mg alloy from the corrosive environment. The corrosion current density of alkali and vanillic acid-treated Mg alloy (AZ31V) almost showed two orders of magnitude lower values in comparison with that of the AZ31 Mg alloy, and the corrosion potential of AZ31V Mg alloy increased from −1.41 to −1.25 V. The immersion tests proved that there was no occurrence of severe corrosion. Hence, the alkali pretreatment and vanillic acid treatment may represent a promising method to improve the corrosion resistance of Mg alloy. 相似文献
90.