全文获取类型
收费全文 | 142683篇 |
免费 | 16709篇 |
国内免费 | 10646篇 |
专业分类
电工技术 | 13190篇 |
技术理论 | 1篇 |
综合类 | 13320篇 |
化学工业 | 17888篇 |
金属工艺 | 9597篇 |
机械仪表 | 10077篇 |
建筑科学 | 11034篇 |
矿业工程 | 4791篇 |
能源动力 | 4020篇 |
轻工业 | 16137篇 |
水利工程 | 5485篇 |
石油天然气 | 4457篇 |
武器工业 | 1923篇 |
无线电 | 15389篇 |
一般工业技术 | 13427篇 |
冶金工业 | 5503篇 |
原子能技术 | 2473篇 |
自动化技术 | 21326篇 |
出版年
2024年 | 909篇 |
2023年 | 2510篇 |
2022年 | 5450篇 |
2021年 | 7035篇 |
2020年 | 5220篇 |
2019年 | 3648篇 |
2018年 | 3842篇 |
2017年 | 4537篇 |
2016年 | 4074篇 |
2015年 | 6189篇 |
2014年 | 7707篇 |
2013年 | 9413篇 |
2012年 | 11135篇 |
2011年 | 11724篇 |
2010年 | 11146篇 |
2009年 | 10812篇 |
2008年 | 11079篇 |
2007年 | 10855篇 |
2006年 | 9419篇 |
2005年 | 7810篇 |
2004年 | 5744篇 |
2003年 | 3860篇 |
2002年 | 3609篇 |
2001年 | 3344篇 |
2000年 | 2695篇 |
1999年 | 1423篇 |
1998年 | 789篇 |
1997年 | 633篇 |
1996年 | 640篇 |
1995年 | 529篇 |
1994年 | 441篇 |
1993年 | 347篇 |
1992年 | 282篇 |
1991年 | 216篇 |
1990年 | 177篇 |
1989年 | 147篇 |
1988年 | 147篇 |
1987年 | 103篇 |
1986年 | 70篇 |
1985年 | 51篇 |
1984年 | 43篇 |
1983年 | 29篇 |
1982年 | 24篇 |
1981年 | 27篇 |
1980年 | 34篇 |
1979年 | 31篇 |
1977年 | 7篇 |
1976年 | 7篇 |
1959年 | 24篇 |
1951年 | 20篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
1.
2.
4.
Multimedia Tools and Applications - In geometry-based point cloud compression, the geometry information is typically compressed using octree coding. In octree coding, the size of the blocks in the... 相似文献
5.
恶意代码数量已经呈现爆炸式增长,对于恶意代码的检测防护显得尤为重要.近几年,基于深度学习的恶意代码检测方法开始出现,基于此,提出一种新的检测方法,将恶意代码二进制文件转化为十进制数组,并利用一维卷积神经网络(1 Dimention Convolutional Neural Networks,1D CNN)对数组进行分类和识别.针对代码家族之间数量不平衡的现象,该算法选择在分类预测上表现良好的XGBoost,并对Vision Research Lab中的25个不同恶意软件家族的9458个恶意软件样本进行了实验.实验结果表明,所提的方法分类预测精度达到了97%. 相似文献
6.
Jiao Zhang Junjie Li Ayesha Murtaza Aamir Iqbal Lijuan Zhu Shinawar Waseem Ali Muhammad Usman Roshan Yameen Siyi Pan Wanfeng Hu 《International Journal of Food Science & Technology》2022,57(2):963-973
This work evaluated the synergistic effects of combined high-intensity ultrasound (HIU) with β-cyclodextrin (β-CD) treatments on inhibiting browning of apple juice and explored the mechanism through simulation system. The combined treatment of 300 W HIU with 0.006 g mL−1 β-CD had a synergistic impact on maintaining juice colour, resulting in a 39.06% reduction in browning degree, only a 36.64% decrease in total phenolic content, and a 17.82% reduction in PPO activity. The inhibition of enzymatic browning in simulated system revealed that HIU suppressed the enzyme (Polyphenol oxidase, PPO) and β-CD inhibited enzyme (PPO) and embedded substrate (polyphenol). The results of spectroscopic analysis showed that the particle-size distribution of PPO narrowed, the content of α-helix in the secondary structure increased, the fluorescence intensity increased, and the maximum wavelength was red-shifted after HIU and β-CD treatment. Changes in structure could further result in PPO activity loss. Hence, the combined treatment could synthetically alleviate the browning of apple juice. 相似文献
7.
8.
Yang Liu Liang-ming Pan Hong-bo Liu 《International Journal of Hydrogen Energy》2021,46(27):13923-13935
Relatively low efficiency is the biggest obstacle to the popularization of water electrolysis, which is a particularly feasible way to produce super-pure hydrogen. Imposing a magnetic field can increase the hydrogen production efficiency of water electrolysis. However, the enhancement's detailed mechanism still lacks an insightful understanding of the bubbles' micro vicinity. Our recent work aims to understand why the micro-magnetohydrodynamic (MHD) convection hinders single bubbles' detachment on the microelectrode. A water electrolysis experiment by microelectrode is performed under an electrode-normal magnetic field, and dynamic analysis of the single bubble growing on microelectrodes is performed. The variation of bubble diameter with time in the presence or absence of the magnetic field was measured, and the forces acting on the bubble were quantified. The result shows that the micro-MHD convection, induced by Lorentz force, can give rise to a downward hydrodynamic pressure force that will not appear in large-scale MHD convection. This force can be of the same magnitude as the surface tension, so it dramatically hinders bubbles' detachment. Besides, the Kelvin force provides a new potential way for further improving the efficiency of water electrolysis. 相似文献
9.
Chunyan Xu Ying Wang Daodong Pan Changyu Zhou Jun He Jinxuan Cao 《International Journal of Food Science & Technology》2021,56(4):1690-1702
To investigate the effect of cooking temperature (55, 65, 75, 85 and 95 °C) on texture and flavour binding of braised sauce porcine skin (BSPS), sensory acceptance, microstructure and flavour-binding capacity were investigated during the processing of BSPS. Samples cooked at 85 and 95 °C showed better texture and aroma scores. Hardness and chewiness of BSPS were obviously improved at 85 and 95 °C than control group. Collagen structure was significantly destroyed over 85 °C. The porcine skin collagen heated at 85 and 95 °C showed relatively higher flavour-binding capacity than other samples. The improvement of texture of BSPS was mainly attributed to the degradation of collagen. Higher aroma scores of BSPS were related to intense binding abilities with aroma compounds at 85 and 95 °C. Cooking at 85 or 95 °C could be an optimal cooking temperature for BSPS. 相似文献
10.