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91.
Kinesins are microtubule-based motor proteins that perform diverse functions[1―6], including the transloca- tion of vesicles, organelles, chromosomes, proteincomplexes, RNA-binding proteins (RNPs), etc. They also help to orchestrate microtubule dynamics …  相似文献   
92.
93.
掺杂纳米半导体超微粒ZnS:Mn2+光学特性研究   总被引:1,自引:1,他引:0  
靳春明  窦恺 《发光学报》1995,16(2):177-179
九十年代对纳米尺寸(nanoscale)材料的光物理性质的深入研究,导致了介于微观与宏观物理间的新的学科一介观物理(mesoscopic physics)的产生.其科学义在于建立和发展介于原子分子和固体之间所谓介观系统(mesoscopic system)的量子理论,揭示介观物质特性及其相互作用本质,并利用介观特性探索新型结构和功能材料.以往对纳米半导体超微粒材料的研究主要集中于与本征特性相关的量子尺寸效应,或缺陷对超微粒本征特性的影响[1,2].超微粒中过渡金属离子中心发光性质研究首次报道于1993年[3,4]并指出这可能成为崭新的一类发光材料.  相似文献   
94.
Dou YH  Bao N  Xu JJ  Meng F  Chen HY 《Electrophoresis》2004,25(17):3024-3031
Separation and detection of proteins have been realized on nonionic surfactant-modified poly(dimethylsiloxane) (PDMS) microfabricated devices with end-column amperometric detection. The hydrophobic PDMS channels are turned into hydrophilic ones after being modified with Brij35 and facilitate the separation of proteins. The coating can remarkably reduce the adsorption of large protein molecules and is stable in the range of pH 6-12. The detection of proteins in such channels needs less rinsing time and thus efficiency is raised. Even large molecules of proteins can also be detected with better reproducibility and enhanced plate numbers. The relative standard deviation (RSD) of the migration time for glucose oxidase (GOD) is 2.2% (n = 19). Separation of GOD and myoglobin has been developed in modified channels. Predominant operational variables, such as the coating conditions, the concentration of surfactant and buffer, are studied in detail.  相似文献   
95.
Tsao  L.  Dou  Kh.  Sun'  G.  Lyu  Yu.  Koroteev  A. M.  Krasnov  G. B. 《Russian Journal of Organic Chemistry》2003,39(3):384-391
The reactivity of melezitose hydroxy groups was studied by tritylation in pyridine with subsequent acetylation. After partial detritylation of the products, acetyl group transfer from position 4 to 6 was observed. The structure of the prepared melezitose derivatives was established on the basis of their IR, 1H, 13C, and 1H-1H COSY NMR, and mass spectra (fast atom bombardment), as well as from the results of model calculations performed with the aid of SGI Indigo Molecule-Pattern-Work-Station software package (Biosym) where the potential energy function was approximated with the CVFF potential. The reactivity of primary hydroxy groups in melezitose was found to decrease in the following order: 6' > 6 6' > 1'.  相似文献   
96.
In this paper, we propose a novel analytic transfer matrix method (ATMM) to the analysis of planar waveguides with index discontinuity or index slope discontinuity, for the cases when the conventional WKB method is no longer valid. We also analyze the physical insight of the approximations in WKB theory, and according to our research, the phase shift at the turning point is not /2, but exactly . Test calculations are done for an index profile with a known solution and the comparison shows that our method gives extremely accurate propagation constant.  相似文献   
97.
We demonstrate the effective generation of red, green and blue (RGB) light in a two-dimensional decagonal quasiperiodic LiNbO3 nonlinear crystal. Owing to the unique abundance in reciprocal vectors (RVs), the RGB signals were generated directly by frequency doublings. Thus the conversion efficiencies of the RGB light were much higher than previously recorded. In addition, the same results were obtained when the crystal was rotated by integral multiples of π/5. This result will aid in the effective generation of RGB in multiple directions and may have important applications in laser-based projection displays. PACS 42.65.Ky; 42.72.Bj; 42.79.Nv  相似文献   
98.
La2O3对Yb:Y2O3透明陶瓷光谱性能的影响   总被引:2,自引:0,他引:2       下载免费PDF全文
研究了La2O3对Yb:Y2O3透明陶瓷光谱性能的影响,添加适量La2O3以后,Yb:Y2O3透明陶瓷的吸收峰和发射峰的位置不变,但由于La3+的离子半径大于Y3+的离子半径,在Y2O3中引入La3+离子后,导致Y2O3晶格常数变大,晶场强度变弱,同时降低了Y2O3晶体的有序度,致使发射峰强度有所下降,发射截面变小.过量的La2O3(x=0.16)造成Yb3+激活离子发射强度明显下降;其荧光寿命在添加La2O3后总体增大45%-60%.  相似文献   
99.
Ultrashort lasers have become powerful tools by inducing extremely nonlinear effects in a wide variety of materials. Femtosecond laser data storage in non-photosensitive media is promising for its high density and fast retrieval.We reviewed the progress of three types of femtosecond laser storage in transparent materials:three-dimensional bit-oriented storage by micro-voids,holographic data storage by two beam interference and storage by computer-generated holograms.  相似文献   
100.
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