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测色仪器与方法的分析研究 被引量:2
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作者 刘补生 《湘潭师范学院学报(社会科学版)》 1993年第6期81-87,共7页
本文介绍了测色原理、方法和仪器,分析了分光测色仪和光电色度计的特点及应用范围的局限性,研究了它们的发展动向,提出了动态在线测色待解决的关键问题。
关键词 测量 光源 透光色 表面 标准光源 光谱刺激值 刺激值 明度 品图 均匀颜空间
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Synthesis and Characterization of Novel Copolymers Based on 3(S)-Methyl-Morpholine-2,5-Dione
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作者 冯亚凯 陈程斌 +2 位作者 张利 田鸿 袁文婕 《Transactions of Tianjin University》 EI CAS 2012年第5期315-319,共5页
A series of novel copolymers were successfully synthesized by ring-opening polymerization (ROP) of 3 (S)-methyl-morpholine-2,5-dione (MMD) and 5-methyl-5-benzyloxycarbonyl-1,3-dioxan-2-one (MBC) using stan- no... A series of novel copolymers were successfully synthesized by ring-opening polymerization (ROP) of 3 (S)-methyl-morpholine-2,5-dione (MMD) and 5-methyl-5-benzyloxycarbonyl-1,3-dioxan-2-one (MBC) using stan- nous octoate as catalyst. The copolymers were characterized by means of ~H-NMR and FT-IR spectroscopy. Gel permeation chromatography (GPC) test shows that the average-number relative molecular mass and average-weight rela- tive molecular mass slightly increase with the increase of MBC content in feed. The results of differential scanning calorimetry (DSC) demonstrate that the glass transition temperature of copolymers increases with the increase of MBC content in copolymers. The copolymers of MMD and MBC are amorphous copolymers, as indicated by DSC results, while the homopolymer of MMD is semicrystalline. 展开更多
关键词 amino acid 3 (S)-methyl-morpholine-2 5-dione 5-methyl-5-benzyloxycarbonyl-l 3-dioxan-2-one ring- opening polymerization copolymer biomaterial
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Study of magneto-optical effects in γ-Fe_2O_3/ZnFe_2O_4 nanoparticle ferrofluids, using circularly polarized light 被引量:3
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作者 FU Jun LI Jian LIN YueQiang LIU XiaoDong MIAO Hua LIN LiHua 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2012年第8期1404-1411,共8页
When circularly polarized light travels through a ferrofluid film in the presence of an applied magnetic field, the transmitted light will behave as elliptically polarized light, because of magnetic birefringence and ... When circularly polarized light travels through a ferrofluid film in the presence of an applied magnetic field, the transmitted light will behave as elliptically polarized light, because of magnetic birefringence and dichroism. The angular distribution of the relative intensity of the transmitted light can be obtained using a polarizer, so that the ratio of both the long and short ax- es-as well as the orientation angle of the ellipse, corresponding to the direction of the applied magnetic field--can be deter- mined, and whether the ferrofluids samples are stable during the measurement can be directly judged from the shape of the distribution curves. Thus, the ratio of the amplitudes Ax/Ay and the added phase difference A r can be resolved in the elliptically polarized light, and information on both the magnetic birefringence An and the dichroism Ak can be deduced for the ferrofluid sample. From the orientation angles of both right-handed and left-handed elliptically polarized transmitted light, the direction of the applied magnetic field can be accurately determined. Using circularly polarized light, the magnetic birefringence and dichroism of pure γ-Fe2O3 ferrofluids and γ--Fe2O3/ZnFe2O4 binary ferrofluids were studied. For the binary ferrofluids, a mod- ulating effect on the magnetic birefringence and dichroism was revealed. 展开更多
关键词 FERROFLUIDS POLARIZATION BIREFRINGENCE DICHROISM
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Electromagnetically Induced Transparency and Absorption of A Monochromatic Light Controlled by a Radio Frequency Field
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作者 蔡勋明 《Communications in Theoretical Physics》 SCIE CAS CSCD 2015年第2期229-235,共7页
Electromagnetically induced transparency and absorption of a monochromatic light controlled by a radio frequency field in the cold multi-Zeeman-sublevel atoms are theoretically investigated. These Zeeman sublevels are... Electromagnetically induced transparency and absorption of a monochromatic light controlled by a radio frequency field in the cold multi-Zeeman-sublevel atoms are theoretically investigated. These Zeeman sublevels are coupled by a radio frequency (RF) field. Both electrom^gnetically induced transparency and electromagnetically induced absorption can be obtained by tuning the frequency of RF field for both the linear polarization and elliptical polarization monochromatic lights. When the transfer of coherence via spontaneous emission from the excited state to the ground state is considered, electromagnetically induced absorption can be changed into electromagnetically induced transparency with the change of intensity of radio field. The transparency windows controlled by the RF field can have potential applications in the magnetic-field measurement and quantum information processing. 展开更多
关键词 electromagnetically induced transparencY electromagnetically induced absorption absorption spectrum
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Phosphine oxide-functionalized polyfluorene derivatives:Synthesis,photophysics,electrochemical properties,and electroluminescence performance 被引量:3
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作者 LIU DeAng GIBSON Gary +2 位作者 BRUG James LAM Sity MAO Samuel S 《Science China Chemistry》 SCIE EI CAS 2011年第4期678-684,共7页
A series of phosphine oxide-functionalized polyfluorene derivatives,PFH-PO-40-1 (P1),PFH-PO-20-1 (P2),PFH-PO-10-1 (P3),and PFH-PO-1-1 (P4),were prepared via a palladium-mediated Suzuki cross-coupling reaction.The stru... A series of phosphine oxide-functionalized polyfluorene derivatives,PFH-PO-40-1 (P1),PFH-PO-20-1 (P2),PFH-PO-10-1 (P3),and PFH-PO-1-1 (P4),were prepared via a palladium-mediated Suzuki cross-coupling reaction.The structures and purities of all polymers were fully characterized by 1H and 13C NMR,UV-vis and photoluminescent spectroscopy,gel permeation chromatography,and TGA/DSC.Their emission features showed single broad peaks at about 445 nm in film,compared with those in dilute solutions,which might be caused by some degree of aggregation in the excited states of the backbones.The best electroluminescence (EL) performance of these polymers with configuration of ITO/PEDOT:PSS/Polymer/Alq3/LiF/Al was obtained from P1 (current efficiency was 4.2 Cd/A at 6V). 展开更多
关键词 organic light-emitting diodes polyfluorene derivatives ELECTROLUMINESCENCE
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Antioxidant and immunomodulatory activities of a polysaccharide from Flammulina velutipes 被引量:15
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作者 Ming Wu Xia Luo +6 位作者 Xiaoyan Xu Wei Wei Mengyao Yu Nan Jiang Liming Ye Zhirong Yang Xiaofan Fei 《Journal of Traditional Chinese Medicine》 SCIE CAS CSCD 2014年第6期733-740,共8页
OBJECTIVE: To evaluate the antioxidant and immunomodulatory activities of a unique polysaccharide from the medicinal fungus Flammulina velutipes in vitro.METHODS: Using water extraction and alcohol precipitation, crud... OBJECTIVE: To evaluate the antioxidant and immunomodulatory activities of a unique polysaccharide from the medicinal fungus Flammulina velutipes in vitro.METHODS: Using water extraction and alcohol precipitation, crude polysaccharides were obtained. After purification by DEAE-cellulose 52 ion exchange chromatography and Sephacryl S-300 HR gel filtration chromatography, High performance liquid chromatography equipped with evaporative light-scattering detector, Infrared radiation and Nuclear magnetic resonance were used to evaluate the structure of the polysaccharide. Its immunomodulatory activity was measured by examining the production of nitric oxide(NO) and cytokine secretion, and via lymphocyte proliferation experiments. Its effects on the scavenging activities of hydroxyl radical, superoxide anion and reducing power were also measured.RESULTS: A water-soluble polysaccharide, Flammulina velutipes polysaccharide I-A(FVP I-A), was obtained with a molecular mass of 8.14×104Da determined by high performance gel permeation chromatography. An in vitro antioxidant assay indicated that FVP I-A could scavenge hydroxyl radical, superoxide anion and possessed reducing power and could largely promote NO production and augment the interleukin-1β, interleukin-6, and tumor necrosis factor-α secretion by RAW264.7 macrophages(P<0.05). Moreover, FVP I-A could promote lymphocyte proliferation(P<0.05), and synergistically enhance the augmentation of the proliferation of mouse lymphocytes by concanavalin A and lipopolysaccharides(P<0.01, P<0.05).CONCLUSION: The FVP I-A obtained from Flammulina velutipes possessed antioxidant activity and could enhance non-specific and specific immune responses in vitro. 展开更多
关键词 Flammulina Isolation purification POLYSACCHARIDES ANTIOXIDANTS IMMUNOMODULATION CYTOKINES
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