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991.
Andreas Wieczorek Hua Yang Brendan Roycroft Frank H. Peters Brian Corbett 《Optical and Quantum Electronics》2013,45(4):365-371
Polarization insensitive optical coupling of a large spot size input waveguide to a small spot size photodiode is achieved by the introduction of a transition waveguide. The coupling efficiency to the photodetector and the related absorption efficiency of the photodiode depend mainly on the refractive indices of the different InGaAsP layers. Waveguide alignments, waveguide widths and the n-contact etch depth do not influence the absorption efficiency relative to a 1-dB tolerance. 相似文献
992.
Yang Guo Chen Corresponding author Zhang Zhi Guo Li Li Guan Rong Hua 《Liquid crystals》2013,40(12):1441-1447
The planar aligned nematic liquid crystal cell with different anchoring for the two substrates (i.e. a non-symmetric NLC cell) is investigated by an analytical method. We deduce the basic equations and the boundary conditions of the tilt angle θ of the LC director. Expressions for threshold and saturation magnetic field are obtained, and numerical results of these two quantities with variation in anchoring parameters of the two substrates are given. A symmetry breaking parameter Δ is introduced and the relations between Δ and applied field, as well as the two sets of anchoring parameters are discussed in detail. A feasible experimental plan for measurement of anchoring strengths of a series of different substrates is proposed. 相似文献
993.
A Pronounced Halogen Effect on the Organogelation Properties of Peripherally Halogen Functionalized Poly(benzyl ether) Dendrons 下载免费PDF全文
Prof. Dr. Yu Feng Hui Chen Zhi‐Xiong Liu Yan‐Mei He Prof. Dr. Qing‐Hua Fan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(14):4980-4990
An interesting halogen‐substituent effect on the organogelation properties of poly(benzyl ether) dendrons is reported. A new class of poly(benzyl ether) dendrons with halo substituents decorating their periphery was synthesized and fully characterized. A systematic study on the gelation abilities, thermotropic behaviors, aggregated microstructures, and mechanical properties of self‐assembled organogels was performed to elucidate the halogen‐substituent effects on their organogelation propensity. It was found that the exact halogen substitutions on the periphery of dendrons exert a profound effect on the organogelation propensity, and dendrons G n ‐Cl (n=2, 3) and G2‐I proved to be highly efficient organogelators. The cooperation of multiple π–π, dispersive halogen, CH–π, and weak C?H ??? X hydrogen‐bonding interactions were found to be the key contributor to forming the self‐assembled gels. Dendritic organogels formed from G n ‐Cl (n=2, 3) in 1,2‐dichloroethane exhibited thixotropic‐responsive properties, and such thixotropic organogels are promising materials for future research and applications. 相似文献
994.
JiGuang Lu Bo Peng Kuo Liu Peng Jiang YouLing Yue Meng Yu Ye-Zhao Yu FeiFei Kou Lin Wang 《中国科学:物理学 力学 天文学(英文版)》2019,(5)
Rotating radio transients(RRATs) are peculiar astronomical objects whose emission mechanism remains under investigation.In this paper, we present observations of three RRATs, J1538+2345, J1854+0306 and J1913+1330, carried out with the Fivehundred-meter Aperture Spherical radio Telescope(FAST). Specifically, we analyze the mean pulse profiles and temporal flux density evolutions of the RRATs. Owing to the high sensitivity of FAST, the derived burst rates of the three RRATs are higher than those in previous reports. RRAT J1854+0306 exhibited a time-dynamic mean pulse profile, whereas RRAT J1913+1330 showed distinct radiation and nulling segments on its pulse intensity trains. The mean pulse profile variation with frequency is also studied for RRAT J1538+2345 and RRAT J1913+1330, and the profiles at different frequencies could be well fitted with a cone-core model and a conal-beam model, respectively. 相似文献
995.
A star edge coloring of a graph is a proper edge coloring such that every connected 2-colored subgraph is a path with at most 3 edges. Deng et al. and Bezegová et al. independently show that the star chromatic index of a tree with maximum degree is at most , which is tight. In this paper, we study the list star edge coloring of -degenerate graphs. Let be the list star chromatic index of : the minimum such that for every -list assignment for the edges, has a star edge coloring from . By introducing a stronger coloring, we show with a very concise proof that the upper bound on the star chromatic index of trees also holds for list star chromatic index of trees, i.e. for any tree with maximum degree . And then by applying some orientation technique we present two upper bounds for list star chromatic index of -degenerate graphs. 相似文献
996.
997.
Zhou Jiahui Jiang Feng Li Sijie Xu Zhijie Sun Wei Ji Xiaobo Yang Yue 《Journal of Solid State Electrochemistry》2019,23(7):1991-2000
Journal of Solid State Electrochemistry - Considering serious pollution from the traditional chemical synthesis process, the resource-rich, clean electrode materials are greatly desired.... 相似文献
998.
With the rapid development of nanoscience and nanotechnology, various types of functional nanoreactors have been designed for diverse applications. Here, the recent evolution of the rational design of nanoreactors for chemical synthesis and biomedical applications are briefly summarized and discussed. The presence of nanoreactors provides constrained space isolated from the surrounding environment. Scientists are committed to studying changes in chemical reactions when the reaction system is confined to the nanosized space. Nanoreactors accelerate the reaction rate and even change mechanism of some chemical reactions. Cells and organelles as natural nanoreactors are also discussed. The development of intracellular synthesis makes it possible to realize various applications in biomedicine. The challenges on the rational design of nanoreactors and perspectives are also discussed. 相似文献
999.
Li Ma Wei Zhang Mingxia Hou Dong Li Fengjuan Liu Xi Du Peng Jiang Zongkui Wang Rong Zhang Haijun Cao Shengliang Ye Changqing Li 《Biomedical chromatography : BMC》2019,33(4)
Intravenous immunoglobulin (IVIg) is increasingly used for the treatment of autoimmune and systemic inflammatory diseases with both licensed and off‐label indications. Recent studies indicated that IVIg‐mediated immunomodulation and anti‐inflammation are closely associated with the IgG sialylation, especially with IgG crystallizable fragment (Fc) sialylation. The sialic acid levels of the IgG molecules and Fc fragments in 12 IVIg preparations from six Chinese manufacturers were evaluated. The Fc fragments were derived from the papain digestion of IVIg, followed by affinity and size exclusion chromatography. The sialic acid levels in Fc fragments and IVIg preparations were determined by high‐performance liquid chromatography with fluorescence detection, after the sialic acid residues were released from the proteins. The results showed that the sialic acid levels in Chinese IVIg preparations ranged from 0.875 (mol/mol IgG) to 1.085 (mol/mol IgG), and the sialic acid levels in Fc fragments were from 0.321 (mol/mol Fc) to 0.361 (mol/mol Fc). Furthermore, the sialic acid levels of IVIg preparations and Fc fragments from different Chinese manufactures were significantly different. These findings will contribute to an increased understanding of Chinese IVIg preparations and the relationship between the sialic acid levels in IVIg preparations and their clinical efficacy in future clinical studies. 相似文献
1000.
Song Zhaorui Yu Lili Sun Yiyang He Hua 《Analytical and bioanalytical chemistry》2019,411(27):7293-7301
Analytical and Bioanalytical Chemistry - A simple, sensitive, and naked-eye assay of metformin (MET), based on the host–guest molecular recognition of cucurbit[6]uril (CB[6])-modified silver... 相似文献