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991.
Xiaofeng Luo Naiwen Kang Lei Li Jianping Deng Wantai Yang 《Journal of polymer science. Part A, Polymer chemistry》2010,48(7):1661-1668
This article reports a class of nanoscale materials, that is, optically active nanoparticles consisting of helical‐substituted polyacetylenes. Such nanoparticles were prepared via aqueous catalytic miniemulsion polymerization, by which nanoparticles with a wide range of size (diameter: 60–400 nm) can be easily prepared. The nanoparticles could be obtained in quantitative monomer conversions. Large specific rotations and intense circular dichroism effects demonstrated that the nanoparticles possessed large optical activities; moreover, the optical activities were found to increase with a decrease in particle size. From the obtained polymer nanoparticles and with poly(vinyl alcohol) (PVA) as supporting material, composite films were further prepared and also exhibited considerable optical activities. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1661–1668, 2010 相似文献
992.
We explore the theoretical and numerical application of local regularization methods to an ill-posed inverse problem arising from financial option pricing. In addition, we provide an algorithm and show results through numerical examples. 相似文献
993.
994.
Y.F. Lu S.M. Huang C.H.A. Huan X.F. Luo 《Applied Physics A: Materials Science & Processing》1999,68(6):647-651
It is demonstrated that a liquid hydrocarbon precursor, cyclohexane, is appropriate for laser-induced carbon deposition. Amorphous
hydrogenated carbon films (a-C:H) were deposited by KrF excimer laser irradiation of single-crystal silicon surface immersed
under cyclohexane. The technique is simple and easy to operate. IR absorption spectra of the deposited films confirmed the
presence of carbon in the diamond phase. Raman and XPS studies showed diamond-like character of the deposited films. Moreover,
these two studies provided strong evidence that laser fluence played an important role in the formation of DLC bondings and
the quality of the deposited films.
Received: 15 September 1998 / Accepted: 5 January 1999 / Published online: 5 May 1999 相似文献
995.
The energy increment spectrum method is developed for the numerical prediction of the appearance and disappearance of a primary (2M: 1)-librational or (M: 1)-rotational resonant separatrix band in a parametrically excited pendulum. The analytical conditions for the presence of such separatrix bands are also obtained. Illustrations of the analytical and numerical results for the appearance and destruction of the resonant bands are given for a comparison. 相似文献
996.
Jie Chen Jin‐Jin Li Zheng‐Hong Luo 《Journal of polymer science. Part A, Polymer chemistry》2013,51(5):1107-1117
In this work, fluorinated nonamphiphilic gradient copolymers of tert‐butyl acrylate (tBA) and 2,2,3,3,4,4,4‐heptafluorobutyl methacrylate (HFBMA) [poly(tBA‐grad‐HFBMA)] were first synthesized by semibatch atom transfer radical copolymerization of tBA and HFBMA. Their hydrolysis at acidic conditions led to amphiphilic poly(acrylic acid‐grad‐HFBMA). The chemical compositions and structures of these copolymers were characterized by proton nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and gel permeation chromatography. Their surface properties were evaluated with water contact angle measurement and x‐ray photoelectron spectroscopy. The micellization behaviors of amphiphilic copolymer were also studied by transmission electron microscopy and dynamic light scattering. The results showed that the fluorinated and amphiphilic gradient copolymers could self‐assemble in a dilute solution to form aggregates of morphologies. Furthermore, the effect of pH on the aggregates was investigated to verify that the resulting gradient copolymers were to some extent pH sensitive. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 相似文献
997.
998.
微孔滤膜富集分光光度法测定铜 总被引:1,自引:0,他引:1
1引言利用微孔滤膜分离和富集样品中的痕量成分,是近年来发展的一项新技术。此技术是依据试样的体积与测定时的有机溶剂的体积比达到富集的目的。由于可高倍数富集及选用有机溶剂溶解收集物及膜,大大改善了检测限;而且过滤装置简易并可用常法测定,具有良好的应用前景。新亚铜灵(NCP)对一价铜来说,几乎是特效试剂,但其测定灵敏度较低,使其应用受到了限制。我们研究了Cu(I)-NCP显色体系,经过微孔滤膜富集后,用二甲基亚现将膜及络合物溶解,然后在分光光度计上测定,其灵敏度大大提高。本方法体系简单,干扰少,选择性和灵敏… 相似文献
999.
1000.
Peptide dendrimers are attractive synthetic polymers and have been widely used as a new generation of biomaterials in recent years. Peptide dendrimers, as well as general dendrimers, may be synthesized to reach nano sizes, and display well-defined architectures, highly-branched structures, high density of functional terminal groups, and controllable molecular weights. On the other hand, peptide dendrimers have properties similar to proteins and some special characteristics, such as good biocompatibility, water solubility and resistance to proteolytic digestion. Due to these advantages, peptide dendrimers have received considerable attention in biomedicine. This review focuses on the development of peptide dendrimers with emphasis on their applications both in diagnostics and in therapy. 相似文献