全文获取类型
收费全文 | 148篇 |
免费 | 21篇 |
国内免费 | 9篇 |
专业分类
化学 | 60篇 |
晶体学 | 3篇 |
力学 | 1篇 |
综合类 | 4篇 |
数学 | 6篇 |
物理学 | 104篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 7篇 |
2020年 | 15篇 |
2019年 | 12篇 |
2018年 | 5篇 |
2017年 | 8篇 |
2016年 | 10篇 |
2015年 | 3篇 |
2014年 | 4篇 |
2013年 | 9篇 |
2012年 | 8篇 |
2011年 | 11篇 |
2010年 | 6篇 |
2009年 | 10篇 |
2008年 | 10篇 |
2007年 | 12篇 |
2006年 | 3篇 |
2005年 | 7篇 |
2004年 | 7篇 |
2003年 | 5篇 |
2002年 | 2篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1994年 | 1篇 |
1993年 | 2篇 |
排序方式: 共有178条查询结果,搜索用时 0 毫秒
21.
22.
《Angewandte Chemie (International ed. in English)》2017,56(50):15828-15845
3D printing is a powerful emerging technology for the tailored fabrication of advanced functional materials. This Review summarizes the state‐of‐the art with regard to 3D laser micro‐ and nanoprinting and explores the chemical challenges limiting its full exploitation: from the development of advanced functional materials for applications in cell biology and electronics to the chemical barriers that need to be overcome to enable fast writing velocities with resolution below the diffraction limit. We further explore chemical means to enable direct laser writing of multiple materials in one resist by highly wavelength selective (λ‐orthogonal) photochemical processes. Finally, chemical processes to construct adaptive 3D written structures that are able to respond to external stimuli, such as light, heat, pH value, or specific molecules, are highlighted, and advanced concepts for degradable scaffolds are explored. 相似文献
23.
Melt electrospinning is relatively under‐investigated compared to solution electrospinning but provides opportunities in numerous areas, in which solvent accumulation or toxicity are a concern. These applications are diverse, and provide a broad set of challenges to researchers involved in electrospinning. In this context, melt electrospinning provides an alternative approach that bypasses some challenges to solution electronspinning, while bringing new issues to the forefront, such as the thermal stability of polymers. This Focus Review describes the literature on melt electrospinning, as well as highlighting areas where both melt and solution are combined, and potentially merge together in the future. 相似文献
24.
黄遵宪从清光绪十七年(1891)到清光绪二十年(1894)出任首任驻新加坡总领事一职,此时正逢晚清洋务运动变法自强,以及中日战争爆发之前的政治危局,而作为英殖民地新加坡的驻外领事,黄遵宪的维新人士和外交人士的双重身份,也使得他置身于新旧时代的夹缝之中。本文以晚清时期黄遵宪在新马地区的活动及其与华人之间的关系为基础,在重新建构清末驻新领事南洋生活的历史大背景下,以海峡殖民地华人社群分化和传统知识分子视野的双重视角,探讨黄遵宪这一时期的社会和文学活动,期望能建构出清末新马华人社会的多元构成的特点,也试图钩沉出晚清知识分子在特定时代的心路历程。 相似文献
25.
玻璃基集成光量子芯片已经应用于量子计算、量子模拟、量子通信、量子精密测量等光量子信息处理领域,显示出强大的功能。文章从量子计算和量子模拟两个方面介绍利用飞秒激光三维高精度直写技术在玻璃中制备集成光量子芯片的重要进展。量子计算芯片包括面向通用量子计算的单比特到多比特光量子逻辑门以及用于解决特定问题的芯片,可实现玻色采样、量子快速傅里叶变换、量子快速到达等功能。在量子模拟方面,玻璃基光量子芯片成为研究关联粒子量子行走动力学和拓扑量子光子学的极佳平台,揭示了一维、二维和合成维度的离散以及连续时间量子行走的演化规律,展示了光子拓扑绝缘体的鲁棒性拓扑模式对量子态传输的保护作用等。 相似文献
26.
J. D. Shakos A. M. Cox D. P. West K. S. West F. A. Wade T. A. King R. D. Blackburn 《Optics Communications》1998,150(1-6):230-234
The processes limiting the rate of response of highly diffractive, reorientationally enhanced photorefractive polymer composite materials are identified from a series of degenerate four wave mixing and Mach–Zehnder interferometric measurements. In the regime of low intensity writing beams charge generation limits the rate of holographic grating formation, but at higher intensities charge transport or reorientation of dye molecules can restrict the rate of grating formation more strongly. A grating risetime of 540 ms is observed in a composite of high dye content with high reorientational mobility of the dye molecules. In this case it is proposed that the charge carrier mobility of the doped poly(N-vinylcarbazole):2,4,7-trinitro-9-fluorenone (PVK:TNF) matrix is the principal limiting factor in grating response rates. 相似文献
27.
细电子束Cockcroft–Walton加速器的研究 总被引:2,自引:0,他引:2
细电子束由加速器通过电子枪发射电子,经电子透镜及偏转射向目标靶.以SDS-3电子束曝光机为基础,完成了电子束Cockcroft-Walton加速器噪声抑制的最优状态实验.系统为加速器调整电路提供一个正比于输入电压的电流.补偿放大器是由一个主放大器和一个辅助放大器组成,辅助放大器消除了主放大器自身的失调漂移.文中介绍了复合调整式Cockcroft-Walton加速器的总体设计方案,给出了实现加速器高稳定度的关键技术措施.从加速器总输出中滤去噪声信号,获得稳定的输出电压,并使电子束曝光机刻蚀出的图形质量和线条分辨率都得到了提高 相似文献
28.
29.
Feng‐Li He Xudong Deng Ya‐Qing Zhou Tuo‐Di Zhang Ya‐Li Liu Ya‐Jing Ye Da‐Chuan Yin 《先进技术聚合物》2019,30(2):425-434
Wound dressing, which can release anti‐infectives in a controlled way, is taking an important role in the treatment and recovery of the open wound. An adequate release of antibiotics can prevent infections from microorganisms effectively. Among the new candidates of fabricating base materials for wound dressing, electrospinning fiber mats are attracting numerous attentions for their excellent performance in controlled drug delivery. The drug release behavior of electrospinning fiber mats can be tuned by changing the chemical components and the geometric structures of the mats. In this study, fiber mats with different geometric structures, which composed of poly‐ε‐caprolactone (PCL), polyethylene glycol (PEG), and ciprofloxacin (Cip) with different blending ratios, were successfully fabricated by direct‐writing melt electrospinning, and the release behavior of Cip were subsequently investigated in vitro. The results showed that the addition of PEG improved the hydrophilicity of the mats, which in turn affected the manner of drug release. The presence of PEG changed the releasing mechanism from a non‐Fickian diffusion into Fickian diffusion, which indicated that the diffusion of Cip from the composite fiber mats became the main factor of drug release instead of polymer degradation. Besides, with the same composition but different geometric structures, the drug release behavior is of significant difference. Therefore, all the Cip‐loaded composite fiber mats showed antibacterial activities but with different efficiency. In summary, the release of the drug could be controlled by adding PEG and changing the geometric structures according to the different requirement of wound dressings. 相似文献
30.