全文获取类型
收费全文 | 135篇 |
免费 | 39篇 |
国内免费 | 13篇 |
专业分类
化学 | 56篇 |
晶体学 | 1篇 |
力学 | 8篇 |
综合类 | 2篇 |
数学 | 3篇 |
物理学 | 117篇 |
出版年
2023年 | 1篇 |
2022年 | 6篇 |
2021年 | 10篇 |
2020年 | 10篇 |
2019年 | 11篇 |
2018年 | 10篇 |
2017年 | 6篇 |
2016年 | 12篇 |
2015年 | 12篇 |
2014年 | 13篇 |
2013年 | 12篇 |
2012年 | 9篇 |
2011年 | 14篇 |
2010年 | 5篇 |
2009年 | 5篇 |
2008年 | 3篇 |
2007年 | 8篇 |
2006年 | 10篇 |
2005年 | 5篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 4篇 |
2001年 | 5篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1990年 | 1篇 |
排序方式: 共有187条查询结果,搜索用时 0 毫秒
1.
Bijian Lan Chunming Liu Xiang Yin Hua Zhang Wei Xu Zhongyi Hua 《Frontiers of Chemistry in China》2006,1(3):296-299
Organic materials of D-π-A type MR-X (MR-1: p-dimethylaminophenylethenetrica-rbonitrile and MR-2: p-diphenylaminophenylethene tricarbonitrile) were designed and synthesized. The device with a sandwich structure shows good
rectificative phenomena. The highest rectification ratio 10000 was achieved in device Cu/MR-1/Ag, and about 100 in other device
M/MR-X/M (M: Cu, Ag). It has been found that rectificative phenomena exist only in the atmosphere-liquid interface region
by means of liquid adsorption, and electric field could help form the oriented molecular film.
__________
Translated from Journal of Fudan University (Natural Science), 2005, 44(4) (in Chinese) 相似文献
2.
直流稳压电源可以将交流电压变换为直流电压,并使之稳定,在我们现实生活中应用很广泛,在实验中我们利用的电学知识,设计制造了一种直流稳压电源。本文简要介绍了这种直流稳压电源波形演示器的设计目的和电路原理,重点阐述了它的制作流程、滤波和稳压原理以及性能测试输出波形。 相似文献
3.
鼻腔结构的改变将伴随鼻腔空气动力学特性改变,进而促使下鼻甲等发生自适应性变化。选取鼻中隔偏曲患者并行鼻中隔偏曲矫正术,部分行下鼻甲骨折外移术,将术前和术后患者行鼻腔CT 扫描,根据CT数据对鼻腔气道进行表面三维重建,运用计算流体动力学方法分析术前和术后鼻腔气道的空气动力学特征。通过研究发现,鼻腔结构矫正手术不是以双侧鼻腔气道容积对称为目的,而是应将整个鼻腔结构看作一个整体,尽可能地保护鼻腔的\绿化带",最终达到重塑鼻腔结构之目的,使鼻腔的生理功能恢复正常。 相似文献
4.
采用4只HSMS 282肖特基二极管阵列,对大功率微波整流电路进行了研究。构造了基于微带线结构的2.45 GHz高效微波整流电路,将微波整流单元电路的输入功率提升到33 dBm。仿真和实验结果表明,在一定微波输入功率的条件下,整流电路在负载较大范围内变化时保持了高整流效率。通过在不同微波输入功率和负载下进行测量,发现当输入微波功率为27.0~31.7 dBm之间变化时,最高整流效率均达到了60%以上,当微波输入功率为30 dBm时,微波整流电路效率达到了63.3%。 相似文献
5.
6.
In living organisms, many biological processes are inextricably linked with light, such as the photosynthesis systems and rhodopsin. Hence, construction of light-sensitive biomimetic-nanochannels, which can realize the functions of cells and other membrane structures with high degree of spatial and temporal control, is particularly attractive and challenging. As a cornerstone of light-sensitive nanochannels, the photoresponsive materials are a big family and at their mature stage after several decades of development, which can provide different strategies to construct biomimetic photoresponsive nanochannels. In this review, we mainly summarize the construction and applications of photoresponsive nanochannels on the basis of various photoresponsive materials. The construction of photoresponsive nanochannels can be classified into four categories: photoresponsive inorganic nanochannels based on inorganic-compound-based photonic sensitive materials; photoresponsive organic nanochannels based on organic-compound-based photonic sensitive materials; photoresponsive polymers nanochannel based on photoresponsive polymers materials and potential photoresponsive nanochannels based on other photoresponsive materials. After introducing the construction of photoresponsive nanochannels, the review highlights some of the most recent applications of photoresponsive nanochannels in separation, energy conversion and storage, drug delivery and so on. 相似文献
7.
The optical rectification (OR) in the two-dimensional electron–hole system is investigated theoretically. An analytical expression formula of the OR coefficient is obtained via the framework of compact density matrix approach and the iterative method. The results show that the OR coefficient depends strongly on the system׳s size and the relaxation time. A more obvious OR coefficient should be found by adjusting an appropriate choice of the system parameters. 相似文献
8.
Development of Complex Mathematical Model of Light Naphtha Isomerization and Rectification Processes
The technique of developing a mathematical model of catalytic isomerization of light naphtha is stated Using experimental data from an industrial isomerization unit shows adequacy of the mathematical model to the real process. The paper presents a method for optimizing the operation of the plant together with catalytic isomerization unit and separation columns. Selection of optimal modes of separation columns allows achieving the desired flow separation between units, as well as extension of the life of the catalyst SI-2. 相似文献
9.
黄希 《原子与分子物理学报》2015,32(6)
通过非平衡态分子动力学方法,研究了锯齿形石墨烯纳米带中掺杂原子硼的两种不同位置排列(三角形硼掺杂和平行硼掺杂)对热导率和热整流的影响并从理论上分析了其变化的原因。研究表明这两种硼掺杂模型在不同温度下导致石墨烯纳米带热导率大约54%-63%的下降;同时发现平行硼掺杂结构对热传递的抑制作用强于三角形硼掺杂结构;硼掺杂结构降低热导率的作用随着温度的升高逐渐减小;三角形硼掺杂结构两个方向上的热导率值具有较大差异,这种结构下的热整流随着温度的上升呈现减弱的趋势;而平行硼掺杂结构两个方向上的热导率值近乎相等,热整流现象表现不明显. 相似文献
10.