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61.
We investigate classical electronic collisions with a He(+) ion. Scattering functions, such as the scattering angle, collisional time, or energy of the outgoing electron, all exhibit an interesting hierarchial self-similar structure, which can be interpreted in terms of the indefinite number of electronic returns to the vicinity of the nucleus, encounters between electrons, and Keplerian excursions of electrons during the collisional processes. Based on this mechanism a binary coding is introduced to organize the dynamics of this three-body system and to provide an understanding of the self-similarity among generations of scale magnification, which yields escape rates that vary with the sectional cut into the parameter space. The self-similarity displayed within a single generation, on the other hand, can be simply tied to the periods of the two independent electronic excursions. The physical interpretation and the symbolic dynamics introduced here are generally useful for three-body collisional systems, including atomic, molecular, or stellar collisions. 相似文献
62.
63.
A new self-assembled and highly oriented one-dimensional single-crystal nanostructure of WO3 with hexagonal form was successfully prepared by a mild, solution-based colloidal approach. 相似文献
64.
Zhu H Pan S Gu S Bradbury EM Chen X 《Rapid communications in mass spectrometry : RCM》2002,16(22):2115-2123
65.
本文制备了一系列富勒烯及其衍生物,并利用多种质谱技术进行了鉴定、表征、揭示了它们在离子源条件下的稳定性及解规律。这些富勒烯及其省生物在FDMS、ISMS中均得到了较强的准分子离子峰且碎片峰很少。结果表昨FDMS,LSIMS技术均适于富勒烯及其衍生物的定性分析,是目前富勒烯分析鉴定中较好的方法。 相似文献
66.
Hongye Tian Jun Shao Rong He Feng Gao Daxiang Cui Hongchen Gu 《Frontiers of Chemistry in China》2006,1(4):474-478
Quantum dots (QDs) were prepared in an organic system through a simple and low-cost wet chemistry method. Polymer beads with
a diameter of 60–70 nm and specific functional groups were synthesized by a particular seeded emulsion polymerization technique.
QDs were embedded in the polymer beads with the specific functional groups through dissolving and swelling method, which provided
the condition for the conjunction of biomolecules and QDs as fluorescent probes. The prepared composites were characterized
with UV-Vis, PL, TEM, FTIR, CLSM and conductance titration etc. The results show that QDs are successfully embedded in polymer
beads, which breaks the limitation that the conjunction of biomolecules and QDs can be achieved only for those synthesized
in aqueous system.
__________
Translated from Journal of Shanghai Jiaotong University, 2005, 39(1) (in Chinese) 相似文献
67.
68.
Gu Ping TANG Zhi Yu WANG 《中国化学快报》2006,17(1):113-116
The work described the synthesis and evaluation of PEI-g-comb-PEG-transferrin as a potential system for gene therapy in vitro. The MW of PEG was 10KDa, and PEI was 2KDa. Its structure was identified by NMR, FT-IR and TGA spectroscopy. MTT assay found that at concentration up to 4000 n mol/L of the polymer, cell viability was over 85%. The bio-character of polymer/DNA complex was characterized by agarose gel electrophoresis, ethidium bromide exclusion and zeta-potential assay. The polymer could retardate DNA at N/P ratio 3.0-3.5 (mol/mol). The particle size of the polymer/DNA complex was less than 300 nm. Transfection efficiency of the complex was studied in COS7 and NT2 cell lines. 相似文献
69.
Calpains are unique calcium-dependent thiol proteases that have been proposed to participate in a number of physiological processes including signal transduction and protein turnover in skeletal muscle. Calpains exist in two major forms. Interestingly, the two forms of protease show no significant difference in their action on various substrates. The only demonstrable difference in their activity involves the concentration of calcium required for activation. Both mu- and m-calpains typically achieve half maximal activation at 50 microM and 0.7 mM calcium, respectively. The focus of this study was to examine the action of both forms of calpain on casein substrates and assess whether any differences could be observed in the resulting peptide finger print using capillary electrophoresis. Purified mu- and m-calpain were incubated for various lengths of time with Oregon Green labeled alphas- and beta-casein. The reactions were stopped with sodium dodecyl sulfate (SDS) and products separated by capillary electrophoresis in micellar electrokinetic capillary chromatography (MEKC) mode using laser-induced fluorescence (LIF) detection. Comparison of the electropherograms showed no difference in the peptide profile for either enzyme. However, it was found that beta-casein was hydrolyzed more extensively than alphas-casein, by both enzymes. Capillary electrophoresis was found to be a very sensitive technique for detection of calpain activity. Using beta-casein as substrate, the CE approach was able to detect 2-3 ng of calpain activity. The results also suggest that capillary electrophoresis is a useful tool for proteolytic investigations of protein structure. 相似文献
70.