全文获取类型
收费全文 | 923篇 |
免费 | 113篇 |
国内免费 | 50篇 |
专业分类
电工技术 | 74篇 |
综合类 | 103篇 |
化学工业 | 123篇 |
金属工艺 | 75篇 |
机械仪表 | 62篇 |
建筑科学 | 44篇 |
矿业工程 | 31篇 |
能源动力 | 19篇 |
轻工业 | 102篇 |
水利工程 | 47篇 |
石油天然气 | 90篇 |
武器工业 | 13篇 |
无线电 | 62篇 |
一般工业技术 | 108篇 |
冶金工业 | 36篇 |
原子能技术 | 12篇 |
自动化技术 | 85篇 |
出版年
2024年 | 13篇 |
2023年 | 30篇 |
2022年 | 39篇 |
2021年 | 53篇 |
2020年 | 42篇 |
2019年 | 30篇 |
2018年 | 31篇 |
2017年 | 40篇 |
2016年 | 23篇 |
2015年 | 42篇 |
2014年 | 38篇 |
2013年 | 40篇 |
2012年 | 46篇 |
2011年 | 55篇 |
2010年 | 55篇 |
2009年 | 43篇 |
2008年 | 69篇 |
2007年 | 36篇 |
2006年 | 30篇 |
2005年 | 27篇 |
2004年 | 19篇 |
2003年 | 14篇 |
2002年 | 22篇 |
2001年 | 18篇 |
2000年 | 29篇 |
1999年 | 27篇 |
1998年 | 20篇 |
1997年 | 19篇 |
1996年 | 28篇 |
1995年 | 26篇 |
1994年 | 14篇 |
1993年 | 12篇 |
1992年 | 13篇 |
1991年 | 10篇 |
1990年 | 8篇 |
1989年 | 10篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 1篇 |
排序方式: 共有1086条查询结果,搜索用时 15 毫秒
1.
Yuqin LiHatsuo Ishida 《Polymer》2003,44(21):6571-6577
Polystyrene nanocomposites have been prepared via solution intercalation method. Combination of wide-angle X-ray diffraction and thermogravimetric analysis is used to study the effect of solvents on the morphology of the nanocomposites as a function of the amount of residual solvent. d-Spacing of the polystyrene nanocomposites has a minimum value when the residual solvent concentration is between 2 and 4 wt%. Different interaction level between the solvent molecules and polymer chains is considered to be the reason for this special d-spacing change behavior. By comparing the solution intercalation of polystyrene and poly(ethyl methacrylate) from different solvents, it is concluded that the interactions between polymer-surfactant, solvent-surfactant, and polymer-solvent play important role for the solution intercalation of polymers. 相似文献
2.
3.
4.
5.
文章结合笔者的实际工作,具体介绍了当前数控车床镗孔刀座的车削试验,分析了镗孔刀座未改之前与改进之后对镗孔震动的作用和影响,为如何有效地解决镗孔震动的问题进行了研究和总结. 相似文献
6.
7.
Run Wang Hengyang Xiang Yan Li Yihui Zhou Qingsong Shan Yuqin Su Zhi Li Yongjin Wang Haibo Zeng 《Advanced functional materials》2023,33(21):2215189
Perovskite light-emitting diodes (PeLEDs) show promising prospects in the wide color gamut display owing to their ultra-narrow full width at half maximum (FWHM). However, up to now, all perovskite white LEDs integrated by standard red, green, and blue perovskite emitters, namely, monolithic white PeLEDs (WPeLEDs), have been rarely reported, owing to facing some issues, e.g., solvent incompatibility in solution technique, ion exchange, and energy transfer between different emission centers. Herein, centered on these issues, an optimal intermediate connection layer (ICL) of Po-T2T/LiF/Ag/HAT-CN/MoO3 is adopted to successfully develop monolithic tandem multicolor PeLEDs and WPeLEDs for the first time. The multicolor PeLEDs can achieve the best external quantum efficiency of 1.8% and the highest luminance of 4844 cd m−2. Besides, the red/green/blue (R/G/B) monolithic tandem WPeLED shows a standard white International Commission on Illumination coordinate of (0.33, 0.33) and achieves an extremely wide color gamut reaching National Television Standards Committee of 130%. This study is the first to realize the standard R/G/B co-electroluminescence in a monolithic perovskite device and offers a feasible strategy for developing wide-color gamut perovskite displays. 相似文献
8.
Yanwei Zhu Wenfang Deng Yueming Tan Jianqiao Shi Jingcheng Wu Wenbo Lu Jianfeng Jia Shuangyin Wang Yuqin Zou 《Advanced functional materials》2023,33(45):2304985
Photocatalytic selective oxidation of 5-hydroxymethylfurfural (HMF) coupled H2 production offers a promising approach to producing valuable chemicals. Herein, an efficient in situ topological transformation tactic is developed for producing porous O-doped ZnIn2S4 nanosheets for HMF oxidation cooperative with H2 evolution. Aberration-corrected high-angle annular dark-field scanning TEM images show that the hierarchical porous O-ZIS-120 possesses abundant atomic scale edge steps and lattice defects, which is beneficial for electron accumulation and molecule adsorption. The optimal catalyst (O-ZIS-120) exhibits remarkable performance with 2,5-diformylfuran (DFF) yields of 1624 µmol h−1 g−1 and the selectivity of >97%, simultaneously with the H2 evolution rate of 1522 µmol h−1 g−1. Mechanistic investigations through theoretical calculations show that O in the O-ZIS-120 lattice can reduce the oxidation energy barrier of hydroxyl groups of HMF. In situ attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) results reveal that DFF* (C4H2(CHO)2O*) intermediate has a weak interaction with O-ZIS-120 and desorb as the final product. This study elucidates the topotactic structural transitions of 2D materials simultaneously with electronic structure modulation for efficient photocatalytic DFF production. 相似文献
9.
Sandwiched Thin‐Film Anode of Chemically Bonded Black Phosphorus/Graphene Hybrid for Lithium‐Ion Battery
下载免费PDF全文
![点击此处可从《Small (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Hanwen Liu Yuqin Zou Li Tao Zhaoling Ma Dongdong Liu Peng Zhou Hongbo Liu Shuangyin Wang 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(33)
A facile vacuum filtration method is applied for the first time to construct sandwich‐structure anode. Two layers of graphene stacks sandwich a composite of black phosphorus (BP), which not only protect BP from quickly degenerating but also serve as current collector instead of copper foil. The BP composite, reduced graphene oxide coated on BP via chemical bonding, is simply synthesized by solvothermal reaction at 140 °C. The sandwiched film anode used for lithium‐ion battery exhibits reversible capacities of 1401 mAh g?1 during the 200th cycle at current density of 100 mA g?1 indicating superior cycle performance. Besides, this facile vacuum filtration method may also be available for other anode material with well dispersion in N‐methyl pyrrolidone (NMP). 相似文献
10.