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981.
Fan Qin Guangfang Li Runming Wang Jiliang Wu Prof. Hongzhe Sun Prof. Rong Chen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(51):16491-16497
Uniform bismuth oxide (Bi2O3) and bismuth subcarbonate ((BiO)2CO3) nanotubes were successfully synthesized by a facile solvothermal method without the need for any surfactants or templates. The synergistic effect of ethylene glycol (EG) and urea played a critical role in the formation of the tubular nanostructures. These Bi2O3 and (BiO)2CO3 nanotubes exhibited excellent CrVI‐removal capacity. Bi2O3 nanotubes, with a maximum CrVI‐removal capacity of 79 mg g?1, possessed high removal ability in a wide range of pH values (3–11). Moreover, Bi2O3 and (BiO)2CO3 nanotubes also displayed highly efficient photocatalytic activity for the degradation of RhB under visible‐light irradiation. This work not only demonstrates a new and facile route for the fabrication of Bi2O3 and (BiO)2CO3 nanotubes, but also provides new promising adsorbents for the removal of heavy‐metal ions and potential photocatalysts for environmental remediation. 相似文献
982.
983.
984.
V. G. Zavodinsky N. V. Lebukhova N. F. Karpovich M. A. Pugachevsky 《Crystal Research and Technology》2010,45(9):969-972
The electron micro diffraction technique and pseudopotential ab initio calculations were implemented to study in details the formation and mechanism of growth of the tungsten whiskers during the reduction of nickel tungstate by CO gas. It has been shown that the W whiskers prefer to grow as crystals oriented in the <111> direction, and this process may be considered as the epitaxial growth on the hexagonal planes of Ni4W particles. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
985.
Fluorescence properties of divalent and trivalent europium ions in CdWO4 single crystals grown by the Bridgman method
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Optical absorption,excitation,and fluorescence were investigated in Eu ion-doped CdWO4 single crystal grown by a modified Bridgman method.The results indicate that Eu2+ and Eu3+ ions coexist in CdWO4 crystal and an energy transfer occurs between these Eu2+ and Eu3+ ions.When the crystal is excited by 266-nm light,the energy corresponding to the 4f65d to 8S7/2 transition of Eu2+ ions results in the excitation of the Eu3+ ions to the 5DJ level.The effect on fluorescence of annealing in oxygen at various temperatures was investigated.The excitation intensity of Eu2+ ions at 266 nm decreases as annealing temperature increases from 300 K to 1073 K,but it remains at a certain equilibrium level when the annealing temperature is further increased. 相似文献
986.
Mehring M Mansfeld D Paalasmaa S Schürmann M 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(6):1767-1781
The reaction of the bismuth silanolates [Bi(OSiR2R')3] (R = R' = Me, Et, iPr; R = Me, R' = tBu) with water has been studied. Partial hydrolysis gave polynuclear bismuth-oxo clusters whereas amorphous bismuth-oxo(hydroxy) silanolates were obtained when an excess of water was used in the hydrolysis reaction. The metathesis reaction of BiCl3 with NaOSiMe3 provided mixtures of heterobimetallic silanolates. The molecular structures of [Bi18Na4O20(OSiMe3)18] (2), [Bi33NaO38(OSiMe3)24].3 C7H8 (3.3 C7H8), [Bi50Na2O64(OH)2(OSiMe3)22].2 C7H8.2H2O (4.2 C7H8.2 H2O), [Bi4O2(OSiEt3)8] (5), [Bi9O7(OSiMe3)13].0.5 C7H8 (6. 0.5C7H8), [Bi18O18(OSiMe3)18)].2C7H8 (7. 2C7H8) and [Bi20O18(OSiMe3)24].3C7H8 (8.3C7H8) are presented and compared with the solid-state structures of [Bi22O26(OSiMe2tBu)14] (9) and beta-Bi2O3. Compound 2 crystallises in the triclinic space group P1 with the lattice constants a = 17.0337(9), b = 19.5750(14), c = 26.6799(16) A, alpha = 72.691(4), beta = 73.113(4) and gamma = 70.985(4) degrees ; compound 3.3C7H8 crystallises in the monoclinic space group P2(1)/n with the lattice constants a = 20.488(4), b = 22.539(5), c = 26.154(5) A and beta = 100.79(3) degrees ; compound 4.2C7H82 H2O crystallises in the monoclinic space group P2(1)/n with the lattice constants a = 20.0518(12), b = 24.1010(15), c = 27.4976(14) A and beta = 103.973(3) degrees ; compound 5 crystallises in the monoclinic space group P2(1)/c with the lattice constants a = 25.256(5), b = 15.372(3), c = 21.306(4) A and beta = 113.96(3) degrees ; compound 6.0.5C7H8 crystallises in the triclinic space group P1 with the lattice constants a = 15.1916(9), b = 15.2439(13), c = 22.487(5) A, alpha = 79.686(3), beta = 74.540(5) and gamma = 66.020(4) degrees ; compound 7.2C7H8 crystallises in the triclinic space group P1 with the lattice constants a = 14.8295(12), b = 16.1523(13), c = 18.4166(17) A, alpha = 75.960(4), beta = 79.112(4) and gamma = 63.789(4) degrees ; and compound 8.3C7H8 crystallises in the triclinic space group P1 with the lattice constants a = 17.2915(14), b = 18.383(2), c = 18.4014(18) A, alpha = 95.120(5), beta = 115.995(5) and gamma = 106.813(5) degrees . The molecular structures of the bismuth-rich compounds are related to the CaF2-type structure. Formally, the hexanuclear [Bi6O8]2+ fragment might be described as the central building unit, which is composed of bismuth atoms placed at the vertices of an octahedron and oxygen atoms capping the trigonal faces. Depending on the reaction conditions and the identity of R, the thermal decomposition of the hydrolysis products [Bi(n)O(l)(OH)(m-)(OSiR3)(3n-(2l-m))] gives alpha-Bi2O3, beta-Bi2O3, Bi12SiO20 or Bi4Si3O12. 相似文献
987.
钨酸铅(PWO)晶体是一种综合性能非常优异的无机闪烁晶体,并且在高能物理研究领域已获得重要应用,但光输出偏低的缺点严重制约了它在非高能物理领域的应用.本文采用氟化铅作为掺杂剂,用Bridgman方法生长出了光输出比普通PWO晶体高出2—3倍的新型PWO晶体.紫外和X射线荧光光谱的测试结果表明,这种新型晶体的发光波长比纯PWO晶体红移了大约134 nm,即为553 nm,衰减时间也从几十纳秒延长到100 ns以上,且光输出随积分时间的增加而增强.此外,发射波长和光输出沿晶体生长方向存在明显的位置依赖性,初期 相似文献
988.
《Analytical letters》2012,45(7):523-536
Abstract The spectrophotometric study was made of red-violet 1, 3-cyclohexanedione bis-thiosemicarbazone-Bi (III) in an acidic dimethylformamide-water solution (λmax = 540 nm, ? = 3.3 × 10?4 1. mol?1. cm?1, stoichiometry 3:1, apparent stability constant (6.0 × 1010). A new method for the spectrophotometric determination of Bi (III) is proposed for concentrations between 0.7 and 7.4 ppm. The relative error (95 % confidence level) is 0.5 % for 3.7 ppm of Bi (III). The extraction with methyl isobutyl ketone of the red-violet complex was also studied spectrophotometrically (λmax = 550 nm, ? = 3.34 × 104 1. mol?1.cm?1, stoichiometry 2:1). A new method for the extraction-spectrophotometric determination of Bi (III) is proposed for concentrations, in aqueous phase, between 0.2 and 1.2 ppm. The relative error (95 % confidence level) is 0.8 % for 0.9 ppm of Bi (III). 相似文献
989.
Two novel complexes,[(C9H18NS2)3Sb(III)](1) and [(C9H18NS2)3Bi(III)](2),were synthesized and characterized by elemental analysis,IR,TG and X-ray single-crystal diffraction.Both 1 and 2 crystallize in the monoclinic system,P21/c space group.The data for 1:a = 1.6964(3),b = 1.02149(17),c = 2.5650(3) nm,β = 121.824(8)°,Z = 4,V = 3.7766(10) nm3,Dc = 1.293 g·cm-3,F(000) = 1536,μ = 1.082 mm-1,the final R = 0.0500,wR = 0.1562 and S =1.072.The data for 2:a = 1.6802(9),b = 1.0256(6),c = 2.5083(10) nm,β = 121.77(3)°,Z = 4,V = 3.675(3) nm3,Dc = 1.486 g·cm-3,F(000) = 1664,μ = 5.159 mm-1,the final R = 0.0481,wR = 0.1055 and S =1.076.The coordinated geometry of the central M(III) with six sulfur atoms from three ligands is a distorted pentagonal pyramid configuration.The dimer structural system is formed by the weak interactions of M…S and C-H…S between two molecules.The complexes were valued for their antibacterial activities by agar-streak method.It was found that 1 is active against the four test bacterial organisms. 相似文献
990.
《Analytical letters》2012,45(8):721-729
Abstract Phosphor luminescence, resulting from the incorporation of trace metal ions into a solid state crystal lattice, has been applied to the quantitative determination of lead and bismuth. The relative fluorescence intensity is linear for 15 to 100 ng of bismuth per spot on calcium carbonate. Lead(II), preconcentrated by co-precipitation with calcium oxalate, can be determined at the ng per ml level by measurement of luminescence after ignition of oxalate to oxide; results are reproducible and the calibration curve is linear up to 15 μg of lead per 100 mg of calcium oxalate precipitate. 相似文献