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61.
CHEN Wu-Hua ZHOU Yun-Long TA Hong-Gui HU Zhi-Biao ZHANG Zhu-Sen QIU Ze-Hai ZHANG Li ZENG Qing-Xin 《结构化学》2009,28(12)
The title compound 1 has been synthesized by the reaction of H_2MoO_4, CdCl_2, H_3PO_4, KF, piperazine hexahydrate and water in aqueous solution under mild hydrothermal conditions. Single-crystal X-ray analysis reveals that the title compound crystallizes in the triclinic system, space group P(-1) with a = 14.049(3), b = 15.972(3), c = 20.043(4) (A), α = 85.82(3), β = 81.28(3),γ = 67.15(3)°, V= 4095.9(14) (A)~3, M_r = 3204.62, Z=2,D_c = 2.598 g/cm~3,μ = 2.360 mm~(-1), F(000) = 3124, the final R = 0.0314, wR = 0.0826 and S = 0.989 for 18592 observed reflections with I > 2σ(I). The crystal packing is stabilized by N-H…O and O-H…O intra- and intermolecular hydrogen bonds to form an infinite 3D network. 相似文献
62.
A convenient label-free fluorescence(FL) nanoprobe for rapid detection of cadmium(Cd) was established using glutathione-capped CdS quantum dots(QDs) and 1,10-phenanthroline(phen). The prepared CdS QDs exhibited a strong FL emission at 536 nm, which could be quenched by phen due to the photoinduced hole transfer(PHT) mechanism. The existence of Cd effectively recovered the FL intensity of CdS QDs, which was due to the easy detachment of phen from the surface of QDs to form[Cd(phen)2(H2O)2]2+ in solution. Cd concentrations were linearly correlated with the FL intensity in the range of 0.0625-1.25 μmol/L under the optimized conditions and the detection limit was 0.01 μmol/L. Finally, the Cd concentration was accurately quantified in real water sample using the proposed sensor. 相似文献
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64.
J.B. Birks 《Journal of luminescence》1974,9(4):311-314
The observed fluorescence parameters (spectrum, quantum yield and lifetime) of an aromatic compound in solution usually differ from its molecular fluorescence parameters, due to self-absorption, secondary fluorescence and/or self-quenching. Neglect of these factors has caused errors in the interpretation of fluorescence data. 相似文献
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66.
J. R. Poulsen J. W. Birks P. van Zoonen C. Gooijer N. H. Velthorst R. W. Frei 《Chromatographia》1986,21(10):587-595
Summary The combination of solid-state peroxyoxalate chemiluminescence detection and post-column chemical reaction systems in liquid
chromatography is investigated. Bis-2,4,6-trichlorophenyloxalate (TCPO) is added from a solid reagent bed with the fluorophore,
3-aminofluoranthene, immobilized on glass beads. Hydrogen peroxide generated photochemically by quinone analytes is measured.
Flow splitting is shown to be a simple means of reagent addition with a negligible band broadening effect. This system is
compared to a more flexible dualpump design. To minimize band broadening in both systems, the reagent bed is located out of
the path of the chromatographic effluent. Detection limits are in the sub-picomole range, an imporvement relative to those
previously reported with TCPO added in the liquid phase. These systems can be easily be adapted for detection of peroxide
generated by other post-column reactions. 相似文献
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68.
A taper transition can couple light between a multimode fiber and several single-mode fibers. If the number of single-mode fibers matches the number of spatial modes in the multimode fiber, the transition can have low loss in both directions. This enables the high performance of single-mode fiber devices to be attained in multimode fibers. We report an experimental proof of concept by using photonic crystal fiber techniques to make the transitions, demonstrating a multimode fiber filter with the transmission spectrum of a single-mode fiber grating. 相似文献
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70.
设计合成了识别Zn2+的荧光传感分子--2-羟基-1-萘甲醛缩-2-萘甲酰腙(3)。 通过红外光谱、核磁共振谱和质谱测试技术表征了其结构。 利用其光谱性质研究了该物质对几种过渡金属离子的识别性质,初步探讨了其结合模式。 结果表明,在乙腈介质中,受体分子3表现出对Zn2+良好的选择性,Zn2+的加入导致受体分子3的吸收光谱在435 nm处出现1新峰,其吸光度逐渐增强,同时于239、302、330、342和387 nm处观察到5个清晰的等吸收点;在516 nm处荧光增强101倍,而其它过渡金属只引起受体分子]3的荧光略微增强。 Job法实验揭示受体分子3与Zn2+的结合比为1∶1。 相似文献