全文获取类型
收费全文 | 66篇 |
免费 | 2篇 |
国内免费 | 3篇 |
专业分类
化学 | 28篇 |
力学 | 1篇 |
综合类 | 2篇 |
数学 | 1篇 |
物理学 | 17篇 |
无线电 | 22篇 |
出版年
2022年 | 3篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 2篇 |
2014年 | 4篇 |
2013年 | 2篇 |
2012年 | 5篇 |
2011年 | 1篇 |
2010年 | 5篇 |
2009年 | 9篇 |
2008年 | 5篇 |
2007年 | 3篇 |
2005年 | 5篇 |
2004年 | 4篇 |
2003年 | 4篇 |
2002年 | 1篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1994年 | 1篇 |
1991年 | 1篇 |
1986年 | 1篇 |
排序方式: 共有71条查询结果,搜索用时 15 毫秒
41.
Samples of wind turbine blade surface have been covered with a superhydrophobic coating made of silica nanoparticles embedded in commercial epoxy paint. The superhydrophobic surfaces have a water contact angle around 152°, a hysteresis less than 2° and a water drop sliding angle around 0.5°. These surfaces are water repellent so that water drops cannot remain motionless on the surface. Examination of coated and uncoated surfaces with scanning electron microscopy and atomic force microscopy, together with measurements of water contact angles, indicates that the air trapped in the cavity enhances the water repellency similarly to the lotus leaf effect. Moreover, this new coating is stable under UVC irradiation and water pouring. The production of this nanoscale coating film being simple and low cost, it can be considered as a suitable candidate for water protection of different outdoor structures. 相似文献
42.
A new galloyl glucoside, 2,6-di-O-acetyl 1-O-galloyl β-D-glucose (1), along with five known phenolic compounds were isolated from the whole plants of Lotus corniculatus. Their structures were elucidated by means of extensive spectroscopic analysis. Compound 1 was assessed for its cytotoxicity against five human tumour lines (HL-60, SMMC-7721, A-549, MCF-7 and SW-480), and the result showed that it had no activity. 相似文献
43.
荷叶表面纳米结构与浸润性的关系 总被引:4,自引:0,他引:4
通过烘烤、化学萃取及物理剥除等方法改变荷叶表面的纳米结构和化学组成, 在环境扫描电镜(ESEM)和全反射红外光谱(ATR)对样品的微观形貌和化学组成进行表征的基础上, 为消除其它外界因素影响样品的真实微观形貌, 进一步采用原子力显微镜(AFM)进行了表征. 通过测量不同处理方法所得样品的表观接触角表征了样品的浸润性质. 结果表明, 荷叶表面的蜡质是产生表面疏水性的根本原因, 其微米级结构放大了其疏水性, 而纳米结构是导致其表面高接触角、低滚动角, 即“荷叶效应”的关键原因. 相似文献
44.
Superhydrophobic polytetrafluoroethylene (Teflon®, DuPont) sub-micro and nanostructures were fabricated by the dipping method, based on anodization process in oxalic acid. The polymer sticking phenomenon during the replication creates the sub-microstructures on the negative polytetrafluoroethylene nanostructure replica. This process gives a hierarchical structure with nanostructures on sub-microstructures, which looks like the same structures as lotus leaf and enables commercialization. The diameter and the height of the replicated nano pillars were 40 nm and 40 μm respectively. The aspect ratio is approximately 1000. The fabricated surface has a semi-permanent superhydrophobicity, the apparent contact angle of the polytetrafluoroethylene sub-micro and nanostructures is about 160°, and the sliding angle is less than 1°. 相似文献
45.
46.
47.
Yunhong Liu Guangji Li 《Journal of colloid and interface science》2012,388(1):235-242
Nature has long been an important source of inspiration for mankind to develop artificial ways to mimic the remarkable properties of biological systems. In this work, a new method was explored to fabricate a superhydrophobic dual-biomimetic surface comprising both the shark-skin surface morphology and the lotus leaf-like hierarchical micro/nano-structures. The biomimetic surface possessing shark-skin pattern microstructure was first fabricated by microreplication of shark-skin surface based on PDMS; and then it was treated by flame to form hierarchical micro/nano-structures that can produce lotus effect. The fabricated biomimetic surfaces were characterized with scanning electron microscopy (SEM), water contact angle measurements and liquid drop impact experiments. The results show that the fabricated dual-biomimetic surface possesses both the vivid shark-skin surface morphology and the lotus leaf-like hierarchical micro/nano-structures. It can exhibit excellent superhydrophobicity that the contact angle is as high as 160° and maintain its robustness of the superhydrophobicity during the droplet impact process at a relatively high Weber number. The mechanism of the micromorphology evolution and microstructural changes on the biomimetic shark-skin surface was also discussed here in the process of flame treatment. This method is expected to be developed into a novel and feasible biomimetic surface manufacturing technique. 相似文献
48.
A novel kind of immobilized enzyme affinity selection strategy based on hollow fibers has been developed for screening inhibitors from extracts of medicinal plants. Lipases from porcine pancreas were adsorbed onto the surface of polypropylene hollow fibers to form a stable matrix for ligand fishing, which was called hollow fibers based affinity selection (HF-AS). A variety of factors related to binding capability, including enzyme concentration, incubation time, temperature, buffer pH and ion strength, were optimized using a known lipase inhibitor hesperidin. The proposed approach was applied in screening potential lipase bound ligands from extracts of lotus leaf, followed by rapid characterization of active compounds using high performance liquid chromatography–mass spectrometry. Three flavonoids including quercetin-3-O-β-d-arabinopyranosyl-(1 → 2)-β-d-galactopyranoside, quercetin-3-O-β-d-glucuronide and kaempferol-3-O-β-d-glucuronide were identified as lipase inhibitors by the proposed HF-AS approach. Our findings suggested that the hollow fiber-based affinity selection could be a rapid and convenient approach for drug discovery from natural products resources. 相似文献
49.
OA系统与MIS系统间数据接口设计与实现 总被引:3,自引:0,他引:3
为了使OA系统的协同工作结果能与企业MIS系统有效地沟通和交换,提高企业的集成工作效率,需设计OA系统的数据接口。深入研究了OA系统数据接口的设计与实现,并实现了一种基于LotusNotes/Domino群件体系结构的OA系统的数据接口。 相似文献
50.
张晓华 《信息技术与信息化》2003,(1):9-10
本文介绍了Notes Domino的结构和基本概念 ,并从数据加密 ,身份认证和访问控制两个方面简单谈一些Notes的安全特性 相似文献