共查询到20条相似文献,搜索用时 578 毫秒
1.
2.
3.
富勒烯-赖氨酸衍生物的合成及其体外抗癌活性研究 总被引:2,自引:0,他引:2
合成了一种新型纳米级富勒烯-赖氨酸衍生物,通过红外光谱、核磁共振、TEM等分析手段对衍生物的组成和结构进行了表征,TEM分析表明其在水溶液中的形貌为理想的球形,平均粒径约为30nm;研究了该衍生物的抗癌机理,体外抗癌活性测试结果表明,该衍生物对人体的骨癌等癌细胞均具有很好的抑制能力,其抑制能力与衍生物的浓度和光照强度有关. 相似文献
4.
5.
对目前国内使用的BCRH型现场混装乳化炸药车在应用中存在的缺陷做了详细研究.为解决这些缺陷,设计开发了一种全自动乳化炸药车装药控制系统.详细阐述了该系统的设备选型和技术方案,论述了该控制系统在应用中的效果和意义. 相似文献
6.
7.
8.
9.
文章介绍了一种乳化炸药专用的植物油酸型Span-80复合乳化剂的制备原理、制备工艺及技术特点.该乳化剂是由植物油酸型Span-80和辅助剂复合而成.实验表明,该复合乳化剂能满足乳化炸药的爆炸性能和贮存稳定性,具有一定的经济效益. 相似文献
10.
11.
Buslov DK 《Applied spectroscopy》2004,58(11):1302-1307
A method for obtaining modified derivatives based on the multiplication of the Fourier image of a normal derivative of degree n by the function (-iSign(x))n has been considered. The thus-obtained modified derivatives of even, odd, and fractional degrees of symmetric functions are also even functions, which permits one to use them for obtaining spectra with a better resolution of individual bands. Also, the use of derivatives of various degrees makes it possible to considerably widen the set of functions suitable for resolving individual bands in overlapped spectra. The results of the application of modified derivatives to synthetic and experimental spectra have been considered. The conclusion has been drawn that practical application of such derivatives permits more flexible variation of the resolution in the resulting spectrum compared to the normal derivatives of only even orders. 相似文献
12.
13.
14.
15.
16.
Optical nonlinearities of five new organophosphorus fullerene derivatives with similar structures were determined by the Z-scan method by use of a nanosecond-pulse laser at 532 nm. The experimental results demonstrate that the five derivatives have much larger excited-state absorption and nonlinear refraction than C60. The excited-state absorption cross sections are nearly two to three times that of C60. Using a five-level model to fit the experimental data, we obtained some parameters such as excited-state absorption and refraction cross sections. A simple analysis of correlations between molecular structure and nonlinear properties is given. Optical nonlinearities of the five new organophosphorus fullerene derivatives were compared with those of some other kinds of fullerene derivatives, and the results show that the nonlinearities of the new derivatives are the larger. 相似文献
17.
T. C. Fung 《International journal for numerical methods in engineering》2004,59(10):1273-1286
In this paper, a simple method based on the scaling and squaring technique for the evaluation of the matrix exponential and its derivatives is presented. A more general formulation with non‐constant first derivatives is considered here. Both higher order and mixed derivatives are investigated. The method is based directly on the property of the exponential function and does not require the use of perturbation formulae for eigenvalues and eigenvectors. The approach provides a simple and direct algorithm for the computation of the matrix exponential and its derivatives regardless of degeneracy in the spectral decomposition of the matrix argument. If the derivatives are taken with respect to the entries of the matrix argument, the first and second linearizations can be obtained directly. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
18.
基于自由振动响应识别颤振导数的特征系统实现算法 总被引:6,自引:0,他引:6
桥梁断面的颤振导数在研究桥梁风致颤振稳定性上扮演着重要的角色,通常通过节段模型风洞试验获得。提出采用时域特征系统实现算法来识别节段模型振动系统的模态参数,进而提取桥梁断面颤振导数的方法。为验证该方法的可行性,进行了二自由度流线型薄平板节段模型自由振动风洞试验,并将识别的气动导数值与Theodorsen理论解进行了比较。 相似文献
19.
目的:综述药用超分子材料环糊精衍生物近年来在国内外的安全性研究进展,以促进国内这方面的研究。方法:从环糊精衍生物在不同制剂应用中的安全性方面概括了其最新研究。结果:环糊精及其衍生物在改善药物理化性质、改进处方、提高药效、降低副作用等方面具有重要价值。除了少数环糊精有较大的毒副作用外,环糊精及其衍生物可以作为安全的药物辅料。结论:有关环糊精及其衍生物的毒副作用的研究尚未完善,如磺丁基醚-β-环糊精的毒副作用以及大部分环糊精及其衍生物的长期毒副作用。我国应大力研究、开发和应用环糊精及其衍生物,以扩展优良的药用辅料。 相似文献
20.
聚噻吩及其衍生物热电材料研究进展 总被引:1,自引:1,他引:0
近来,聚合物热电材料因其成本低、资源丰富、热导率低等优势被认为是最有前途的热电材料之一。聚噻吩及其衍生物是研究较为广泛的一类聚合物热电材料。综述了近年来聚噻吩、聚噻吩衍生物以及聚噻吩基/无机复合热电材料在热电领域的研究进展。已有研究表明,聚噻吩及其衍生物热电材料具有高的Seebeck系数,其See-beck系数与电导率通常是此消彼长的关系。通过制备低维材料,与高电导率的无机纳米材料复合以及适度掺杂等方法可有效提高聚噻吩及其衍生物的热电性能。 相似文献