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161.
Qing Yan Yeping Wu Kuo Han Yanhua Luo Qijin Zhang 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2010,75(3):992-996
Poly(N-isopropylacrylamide)-b-poly{6-[4-(4-methylphenyl-azo)phenoxy]hexylmethacrylate} (PNIPAM32-b-PAzoMM8) and poly(N-isopropylacrylamide)-b-poly{6-[methyl(4-nitrophenyldiazenyl)phenyl]aminohexylmethacrylate} (PNIPAM32-b-PAzoNO10) were prepared by reversible addition–fragmentation chain transfer (RAFT) radical polymerization. The optical properties of Eu(DBM)3Phen (Eu, Europium; DBM, dibenzoylmethide; Phen, 1,10-phenanthroline)-doped azobenzene-containing copolymer vesicle solutions were studied by UV–vis and fluorescence spectroscopy. When the electronic transition bands of azobenzene and Eu(DBM)3Phen overlapped at about 350 nm in PNIPAM32-b-PAzoMM8, the fluorescent emission intensity at 612 nm of Eu(DBM)3Phen could be modulated by irradiation with UV and visible light. However, when the absorption of the azobenzene-moiety red-shifted to 477 nm in PNIPAM32-b-PAzoNO10, the luminescence intensity of Eu(DBM)3Phen was not affected any longer. The difference between these two systems was possibly caused by the energy allocation in the luminescence process, which was discussed in detail. 相似文献
162.
Yu CC Chen HW Chen MJ Chang YC Chien SC Kuo YH Yang FL Wu SH Chen J Yu HH Chao LK 《Natural product communications》2010,5(12):1941-1944
The present study investigated the chemical composition of Isochrysis galbana Parke, a marine microalga which is widely used as a feedstock in aquaculture. From gas chromatography/mass spectrometric analysis the mono-sugar compositions of I. galbana were 2.1% fucose, 2.5% rhamnose, 2.7% arabinose, 8.5% xylose, 15.7% mannose, 32.7% galactose and 35.8% glucose. The polysaccharides of I. galbana were able to induce prointerleukin-1beta (pro-IL-1beta) protein expression within murine macrophages. Furthermore, five kinds of chlorophyll and one sterol were separated from the ethanolic extracts, including pheophorbide-a, ethyl pheophorbide-a, 10S-10-hydroxypheophytin-a, 10R-10-hydroxypheophytin-a, (132-R)-pheophytin-a, and brassicasterol. In addition, the major soluble components of the ethanol/n-hexane extract were 9-octadecenoic acid (E) (38.4%), hexadecanoic acid (23.3%), tetradecanoic acid (15.7%), and octadecanoic acid (7.2%), but only a few polyunsaturated fatty acids were found, such as 9,12,15-octadecatrienoic acid (1.9%), 9,12-octadecadienoic acid (Z,Z) (3.4%), and docosahexaenoic acid (0.2%). This is the first occasion that polysaccharides from I. galbana have been demonstrated to exert immunomodulatory properties by the induction of IL-1 within macrophages. 相似文献
163.
In this paper, we show that a multiplication operator on the Dirichlet space D is unitarily equivalent to Dirichlet shift of multiplicity n + 1 (n ≥ 0) if and only if its symbol is c zn+1 for some constant c. The result is very different from the cases of both the Bergman space and the Hardy space. 相似文献
164.
D.Y. Lin T.P. Huang Y.C. Kao C.C. Huang H.C. Kuo Li Chang 《Physica E: Low-dimensional Systems and Nanostructures》2011,44(3):659-664
In this study, we present the optical characteristics of A-plane ZnO/ZnMgO multiple quantum wells (MQWs) with different well widths grown on R-plane sapphire substrates by pulsed laser deposition (PLD). The energy gaps of ZnO and ZnMgO have been observed by photoluminescence (PL) and absorption spectra. The electrons confined in the ZnO wells transit from the electron ground sub-band to the heavy-hole ground sub-band (noted as 11H) located at 3.40 and 3.57 eV for the ZnO/ZnMgO MQWs samples with well widths of 5.6 and 1.2 nm, respectively. The strong anisotropic polarization characteristic has been studied by polarization-dependent PL measurements. For comparison, we also calculated the transition energies of different well thicknesses varying from 1 to 6 nm. The theoretical results match quite well with the experimental values and revealing the suitable conduction band offset Qc=0.6. The temperature dependence of PL spectra is being investigated, in the temperature range between 10 and 300 K. 相似文献
165.
Bin Xia Yu WuHui Wen Ho Chang KeWen Dong Song Cheng Hon Alfred HuanJer Lai Kuo Wei Guang ZhuLan Wang 《Physica B: Condensed Matter》2011,406(17):3166-3169
Room temperature ferromagnetism in both transition-metals doped and undoped semiconductor thin films and nanostructures challenges our understanding of the magnetism in solids. In this report, we performed the magnetic measurement and Andreev reflection spectroscopy study on undoped Indium-Tin oxide (ITO) thin films and bulk samples. The magnetic measurement results of thin films show that the total magnetization/cm2 is thickness independent. Prominent ferromagnetism signal was also discovered in bulk samples. Spin polarized electron transports were probed on ITO thin film/superconductor interface and bulk samples surface/superconductor interface. Based on the magnetic measurement results and spin polarization measurement data, we propose that the ferromagnetism in this material originates from the surface spin polarization and this surface polarization may also explain the room temperature ferromagnetism discovered in other undoped oxide semiconductor thin films and nanostructures. 相似文献
166.
This paper experimentally compares the intensity and phase detection sensitivities of grating coupling surface plasmon resonance
(SPR). A simple air-heating method is proposed to implement tiny refractive index changes. An electro-optic heterodyne interferometer
is used to obtain both the intensity and phase curves of the grating coupling SPR device. The transient reflectivity and phase
curves during the heating process are recorded. The result shows that the phase detection sensitivity is much better than
that of the intensity by an order of magnitude. 相似文献
167.
This study demonstrates a tunable Fresnel lens in an azo-dye-doped liquid crystal (ADDLC) film using an interference technique. One Fresnel-patterned green beam using a Sagnac interferometer irradiated the UV-illuminated ADDLC cell, yielding a concentric zone plate distribution with homeotropic and isotropic structures in bright and dark regions of the green interference pattern. The proposed Fresnel lens is polarization independent, focus tunable, and the focusing efficiency of the device can be optically controlled. 相似文献
168.
Yung-I Chen Bo-Lu LinYu-Chu Kuo Jen-Ching Huang Li-Chun Chang Yu-Ting Lin 《Applied Surface Science》2011,257(15):6741-6749
To prevent Co diffusion from cemented carbides at high temperatures, we fabricated TaNx coatings by reactive direct current (d.c.) magnetron sputtering onto 6 wt.% cobalt cemented carbide substrates, to form diffusion barrier layers. Varying the nitrogen flow ratio, N2/(Ar + N2), from 0.05 to 0.4 during the sputtering process had a significant effect on coating structure and content. Deposition rate reduced as the nitrogen flow ratio increased. The effects of nitrogen flow ratio on the crystalline characteristics of the TaNx coatings were examined by X-ray diffraction. The TaNx coatings annealing conditions were 500, 600, 700, and 800 °C for 4 h in air. We evaluated the performance of the diffusion barrier using both Auger electron spectroscopy depth-profiles and X-ray diffraction techniques. We also investigated oxidation resistance of the TaNx coatings annealed in air, and under a 50 ppm O2-N2 atmosphere, to evaluate the fabricated layers effectiveness as a protective coating for glass molding dies. 相似文献
169.
Defang Duan Xiaoli Huang Changbo Chen Fubo Tian Kuo Bao Da Li Yunxian Liu Hongyu Yu Bingbing Liu Tian Cui 《ChemInform》2014,45(49):no-no
The high pressure crystal structure of BI3 with space group P21/c consisting of B2I6 dimers is determined using an ab initio evolutionary algorithm for crystal structure prediction in conjunction with density functional theory. 相似文献
170.
A novel and efficient microwave-assisted one-pot reaction was developed to synthesize angular 2,2-dimethyl-2H-chromone-containing compounds, which is the first and key step in the synthesis of potent DCK and DCP anti-HIV agents. The newly developed microwave synthesis conditions dramatically shortened the reaction time from 2 days to 4 h with improved yields. 相似文献