全文获取类型
收费全文 | 87811篇 |
免费 | 6388篇 |
国内免费 | 2925篇 |
专业分类
电工技术 | 4347篇 |
技术理论 | 9篇 |
综合类 | 4649篇 |
化学工业 | 15514篇 |
金属工艺 | 4445篇 |
机械仪表 | 5234篇 |
建筑科学 | 7028篇 |
矿业工程 | 1985篇 |
能源动力 | 2480篇 |
轻工业 | 4908篇 |
水利工程 | 1447篇 |
石油天然气 | 4539篇 |
武器工业 | 488篇 |
无线电 | 10445篇 |
一般工业技术 | 11301篇 |
冶金工业 | 6107篇 |
原子能技术 | 831篇 |
自动化技术 | 11367篇 |
出版年
2024年 | 324篇 |
2023年 | 1315篇 |
2022年 | 2280篇 |
2021年 | 3099篇 |
2020年 | 2336篇 |
2019年 | 2029篇 |
2018年 | 2256篇 |
2017年 | 2518篇 |
2016年 | 2359篇 |
2015年 | 2942篇 |
2014年 | 4018篇 |
2013年 | 5073篇 |
2012年 | 5243篇 |
2011年 | 5519篇 |
2010年 | 4901篇 |
2009年 | 4716篇 |
2008年 | 4467篇 |
2007年 | 4403篇 |
2006年 | 4648篇 |
2005年 | 4133篇 |
2004年 | 2784篇 |
2003年 | 2501篇 |
2002年 | 2192篇 |
2001年 | 2019篇 |
2000年 | 2282篇 |
1999年 | 2605篇 |
1998年 | 2880篇 |
1997年 | 2135篇 |
1996年 | 1912篇 |
1995年 | 1548篇 |
1994年 | 1280篇 |
1993年 | 953篇 |
1992年 | 662篇 |
1991年 | 557篇 |
1990年 | 420篇 |
1989年 | 385篇 |
1988年 | 327篇 |
1987年 | 184篇 |
1986年 | 178篇 |
1985年 | 126篇 |
1984年 | 98篇 |
1983年 | 66篇 |
1982年 | 68篇 |
1981年 | 62篇 |
1980年 | 50篇 |
1979年 | 32篇 |
1978年 | 19篇 |
1977年 | 69篇 |
1976年 | 70篇 |
1975年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
41.
42.
Qin-yu Zhou Shan Zhao Yan-yan Huang Jin-shuang Hu Jia-hua Kuang Dong-mei Liu Charles S. Brennan 《International Journal of Food Science & Technology》2021,56(6):2992-3003
Yogurt preserves and enhances nutritional value of milk. In this study, we have compared several strains to determine the physicochemical, sensory, rheological and aroma characteristics of different yogurts. We used Lactobacillus gasseri LGZ 1029 (LG), commercial probiotic L. rhamnosus (LGG) and traditional fermentation strains Streptococcus thermophilus and L. bulgaricus (SL). Results showed that the flavour and texture characteristics of mixed-strain yogurts were obviously better than in single-strain yogurts. Addition of LG increased pseudoplastic behaviour, as shown by Herschel–Bulkley model analysis of rheological behaviour. The LG + SL group also had both the highest viscosity consistency index and thickening ability. In addition, a total of 57 volatile compounds were detected in yogurts and the fermentation with the addition of LG was mainly affected by ketones. Our study suggested that a yogurt with new attributes can be produced by using LGZ 1029. 相似文献
43.
Mengting Ma Zijun Li Feng Yang Huaixiang Wu Wuyang Huang Zhongquan Sui Harold Corke 《International Journal of Food Science & Technology》2021,56(7):3607-3617
Waxy, normal and high-amylose maize starches were subjected to heat-moisture treatment (HMT) and then added to wheat flour (WF) in different ratios (1%, 5% and 10%). The properties of blends and their cooked noodles were studied to investigate the effects of HMT starches. The incorporation of HMT starch in WF led to an increase in swelling power, peak viscosity and breakdown and to a decrease in setback, thus inhibiting retrogradation, hence enhancing resultant noodle softness. Compared to the same addition ratio of native starch to WF, HMT starch led to higher tensile strength and extensibility in resultant noodles. WF with added HMT starch had higher resistant starch than with native starch. This study showed that addition of HMT maize starch has potential to bring nutritional benefits. However, it is necessary to select the proper blending ratio and amylose content of starch to add, in consideration of its effect on noodle quality. 相似文献
44.
45.
Wei-Li Xie Xiao-Dong Zhang Wen-Hui Liu Qi Xie Guang-Wu Wen Xiao-Xiao Huang Jian-Dong Zhu Fei-Xiang Ma 《稀有金属(英文版)》2019,(3)
SiC nano wires were fabricated on the silicon substrate dipped with a layer of Ni catalyst at 900 ℃ by gas pressure annealing processing. The morphologies and crystal structures were determined by scanning electron microscopy(SEM), transmission electron microscopy(TEM)and X-ray diffraction(XRD). The results show that the assynthesized nanowires are β-SiC single crystalline with diameter range of 50-100 nm, and length of tens of micron by directly annealing at 900 ℃. The SiC nano wires grow along the [111] direction with highly uniform morphology. And the possible growth mechanism of SiC nano wires is proposed.The present work provides an efficient strategy for the production of high-quality SiC nano wires. 相似文献
46.
Wen Cao Zhonghua Zhou Chenyu Li Qun Wang Yue Huang Shirley Shen 《Ceramics International》2021,47(2):1807-1818
Sodalime float (SF) glass is widely used in our societies and industries. Hydrothermal corrosion method is one of the effective ways to prepare a superhydrophobic glass, but there is still lack of knowledge about hydrothermal corrosion behavior and mechanism of SF glass. We have hydrothermally treated SF glass at 180 °C for different time, and tried to reveal the aqueous corrosion process of SF glass. We have characterized the morphologies and chemical compositions of samples, and found that (1) the two sides of SF glass have different corrosion resistances, and (2) a multilayer structural coating with a nanoflake layer (Mg-rich gel layer), a nanowire layer (Ca-rich gel layer), and a porous layer (etched layer) is formed on the air-side of SF glass. Based on the experimental results, we have proposed an aqueous corrosion mechanism of SF glass. The insights of the hydrothermal corrosion behaviors and mechanism provide helpful guidelines to glass surface structural control and functionalization. 相似文献
47.
Qinhua Wang Xiaofeng Pan Xinpin Wang Shilin Cao Lihui Chen Xiaojuan Ma Liulian Huang Yonghao Ni 《Ceramics International》2021,47(4):4398-4403
Ti3C2Tx (MXene), a new kind of 2D ceramic nanosheets, is receiving more and more attention in the fields of medicine, biology, energy, electronics, etc. However, the preparation and application of MXene in hydrogel is still in its infancy period. Here, we review the latest progress (after 2018) related to MXene hydrogels in time. Aiming at the key issue of the dispersion stability of MXene in hydrogel systems, the preparation strategy, mechanism, advantages and disadvantages of MXene hydrogels are sorted out in detail, and the potential application prospects of MXene composite hydrogel are introduced. Finally, future viewpoints are put forward for the dispersion stability challenges that need solving in the design of MXene hydrogel. 相似文献
48.
Yang Yueyi Wang Lide Chen Huang Wang Chong 《Analog Integrated Circuits and Signal Processing》2021,107(3):605-616
Analog Integrated Circuits and Signal Processing - Fault diagnosis of analog circuit is critical to improve safety and reliability in electrical systems and reduce losses. Traditional fault... 相似文献
49.
50.
针对大型旋转机械通过临界转速时振动过大及运行中故障频发等问题,搭建转子试验台,模拟启停机过程和碰摩、不对中故障。不改变原有支撑形式,安装自主设计的磁流变阻尼器,在不停机的情况下,试验研究阻尼器抑制转子通过临界转速时振动过大及各类故障振动。试验结果表明,阻尼器可以有效抑制转子系统临界转速附近的振动,降幅在60%以上;转子发生碰摩或不对中故障时,阻尼器可以降低其高倍频振动。 相似文献