The title compound belongs to monoclinic, space group C2/c with a = 5.2694（1）, b = 12.6659（4）, c = 19.4108（2） A,β= 91.504（2）°, V = 1295.06（5） A^3, Z = 4 and Dc= 5.599 g/cm^3. The structure of BaGd2（M...The title compound belongs to monoclinic, space group C2/c with a = 5.2694（1）, b = 12.6659（4）, c = 19.4108（2） A,β= 91.504（2）°, V = 1295.06（5） A^3, Z = 4 and Dc= 5.599 g/cm^3. The structure of BaGd2（MoO4）4 contains a MoO4 tetrahedron, a distorted GdO8 polyhedron, and Ba^2＋ ions in a tenfold coordination. The GdO8 polyhedra are linked together through edge-sharing to give a two-dimensional Gd layer. The MoO4 tetrahedra connected to the Gd atoms are capped up and down the Gd layer through common oxygen apices, thus-forming a new Gd-Mo layer. Finally, the Gd-Mo layers are held together through bridging BaO10 polyhedra to form a three-dimensional framework. Since the Ba-μ3-O bond has a large average distance of 2.888 A, this structural characteristic will result in a cleavage along the （001） plane.展开更多
2,4(5)-Dinitroimidazole(2,4(5)-DNI)is an important organic intermediate,and itself can also be used for energetic material.In this work,the solubility of 2,4(5)-DNI in(methanol+water,acetonitrile+water,acetone+water)b...2,4(5)-Dinitroimidazole(2,4(5)-DNI)is an important organic intermediate,and itself can also be used for energetic material.In this work,the solubility of 2,4(5)-DNI in(methanol+water,acetonitrile+water,acetone+water)binary solvents were measured by using a dynamic test method from 278.15 K to 323.15 K under 101.1 k Pa.The Jouyban–Acree model,van't Hoff–Jouyban–Acree model,Apelblat–Jouyb an–Acree model,Ma model,and Sun model were used to correlate the experimental data.The values of relative average deviation(RAD)and root-mean-square deviation(RMSD)were very small,indicating that the error between the experimental value and the correlated value was very small.The thermodynamic parameters such as dissolution enthalpy,dissolution entropy and Gibbs energy were calculated based on solubility data.High-purity of 2,4(5)-DNI was efficiently obtained by using cooling and dilution crystallization method.展开更多
Polycrystalline Gd2(MoO4)3:Dy3+ phosphors have been synthesized by high temperature solid-state reaction method. The phosphors were characterized with X-ray diffractometer, thermogravimetric analysis and different sca...Polycrystalline Gd2(MoO4)3:Dy3+ phosphors have been synthesized by high temperature solid-state reaction method. The phosphors were characterized with X-ray diffractometer, thermogravimetric analysis and different scanning calorimeter, scanning electron microscopy, and photoluminescence spectrofluorimeter. Several peaks at 351, 389, 425, 452, and 472 nm appeared in photoluminescence excitation spectrum, which matched well with the emission of the ultraviolet (UV) and blue-light emitting diode (LED) chips. Upon excitation at 389 nm UV light, intense emissions centered at 484, 575 and 668 nm were attributed to the transitions of 4F9/2→6H15/2, 4F9/2→6H13/2 and 4F9/2→6H11/2 of Dy3+, respectively. The chromaticity coordinates and correlative color temperatures have been calculated and presented in the Commission International de I’Eclairage (CIE) diagrams. The results indicated that Gd1.9(MoO4)3:Dy0.13+ with CIE coordinates of (x=0.38, y=0.41) and the correlative color temperature of 4134 K is a potential candidate for white LEDs.展开更多
Single crystal of Li2Zn2（MoO4）3 has been grown from a flux of Li2MoO4 by the top-seeded solution-growth method, and its stnicture was refined by the Rietveld method. It belongs to the orthorhombic system, space grou...Single crystal of Li2Zn2（MoO4）3 has been grown from a flux of Li2MoO4 by the top-seeded solution-growth method, and its stnicture was refined by the Rietveld method. It belongs to the orthorhombic system, space group Pnma with a = 5.1114, b = 10.4906 and c = 17.6172A. Good agreement between the experimental and calculated profile （Rp = 6.69%, Rwp = 9.73% and Rexp = 6.58%） was reached.展开更多
The spectral parameters of Nd^3＋ ions in Nd^3＋-doped NaGd（MoO4）2 crystal have been investigated based on Judd-Ofelt theory and obtained as follows： The intensity parameters Ωeff are Ω2 = 24.77×10^20, Ω4 =...The spectral parameters of Nd^3＋ ions in Nd^3＋-doped NaGd（MoO4）2 crystal have been investigated based on Judd-Ofelt theory and obtained as follows： The intensity parameters Ωeff are Ω2 = 24.77×10^20, Ω4 = 7.31×10^-20 and Ω6 = 6.91×10^-20 cm^2. The radiative lifetime is 100 μs, and the quantum efficiency is 93.9%. The fluorescence branch ratios were calculated to be β1 = 0.441, β2 = 0.469,β3 = 0.086 and β4=0.004.展开更多
通过共沉淀法合成了CuCr_(2)O_(4)黑色颜料。研究了沉淀剂(即尿素、氨水、氢氧化钠)对相组成和颜色性能的影响。同时,计算了以氨水和氢氧化钠为沉淀剂时CuCr_(2)O_(4)的结晶动力学和结晶机制。结果表明,由于两种离子(Cu^(2+)和Cr^(3+))...通过共沉淀法合成了CuCr_(2)O_(4)黑色颜料。研究了沉淀剂(即尿素、氨水、氢氧化钠)对相组成和颜色性能的影响。同时,计算了以氨水和氢氧化钠为沉淀剂时CuCr_(2)O_(4)的结晶动力学和结晶机制。结果表明,由于两种离子(Cu^(2+)和Cr^(3+))的溶解度不同,沉淀过程的最佳pH值为7.5;由于产物中存在Cr2O3,尿素不适合作为沉淀剂。氨水作为沉淀剂时,CuCr_(2)O_(4)结晶的活化能为120.2 k J/mol,氢氧化钠作为沉淀剂时为141.3 k J/mol。CuCr_(2)O_(4)的结晶过程涉及成核和三维生长。较小的结晶活化能得到的CuCr_(2)O_(4)颗粒细小,分散均匀,呈色性能更优异。展开更多
基金the National Natural Science Foundation of China (No. 60378031)Key Project of Science and Technology of Fujian Province (2001F004)
文摘The title compound belongs to monoclinic, space group C2/c with a = 5.2694（1）, b = 12.6659（4）, c = 19.4108（2） A,β= 91.504（2）°, V = 1295.06（5） A^3, Z = 4 and Dc= 5.599 g/cm^3. The structure of BaGd2（MoO4）4 contains a MoO4 tetrahedron, a distorted GdO8 polyhedron, and Ba^2＋ ions in a tenfold coordination. The GdO8 polyhedra are linked together through edge-sharing to give a two-dimensional Gd layer. The MoO4 tetrahedra connected to the Gd atoms are capped up and down the Gd layer through common oxygen apices, thus-forming a new Gd-Mo layer. Finally, the Gd-Mo layers are held together through bridging BaO10 polyhedra to form a three-dimensional framework. Since the Ba-μ3-O bond has a large average distance of 2.888 A, this structural characteristic will result in a cleavage along the （001） plane.
文摘2,4(5)-Dinitroimidazole(2,4(5)-DNI)is an important organic intermediate,and itself can also be used for energetic material.In this work,the solubility of 2,4(5)-DNI in(methanol+water,acetonitrile+water,acetone+water)binary solvents were measured by using a dynamic test method from 278.15 K to 323.15 K under 101.1 k Pa.The Jouyban–Acree model,van't Hoff–Jouyban–Acree model,Apelblat–Jouyb an–Acree model,Ma model,and Sun model were used to correlate the experimental data.The values of relative average deviation(RAD)and root-mean-square deviation(RMSD)were very small,indicating that the error between the experimental value and the correlated value was very small.The thermodynamic parameters such as dissolution enthalpy,dissolution entropy and Gibbs energy were calculated based on solubility data.High-purity of 2,4(5)-DNI was efficiently obtained by using cooling and dilution crystallization method.
基金Project supported by the National Natural Science Foundation of China (50872036)
文摘Polycrystalline Gd2(MoO4)3:Dy3+ phosphors have been synthesized by high temperature solid-state reaction method. The phosphors were characterized with X-ray diffractometer, thermogravimetric analysis and different scanning calorimeter, scanning electron microscopy, and photoluminescence spectrofluorimeter. Several peaks at 351, 389, 425, 452, and 472 nm appeared in photoluminescence excitation spectrum, which matched well with the emission of the ultraviolet (UV) and blue-light emitting diode (LED) chips. Upon excitation at 389 nm UV light, intense emissions centered at 484, 575 and 668 nm were attributed to the transitions of 4F9/2→6H15/2, 4F9/2→6H13/2 and 4F9/2→6H11/2 of Dy3+, respectively. The chromaticity coordinates and correlative color temperatures have been calculated and presented in the Commission International de I’Eclairage (CIE) diagrams. The results indicated that Gd1.9(MoO4)3:Dy0.13+ with CIE coordinates of (x=0.38, y=0.41) and the correlative color temperature of 4134 K is a potential candidate for white LEDs.
基金the National Natural Science Foundation of China (No. 50672123)
文摘Single crystal of Li2Zn2（MoO4）3 has been grown from a flux of Li2MoO4 by the top-seeded solution-growth method, and its stnicture was refined by the Rietveld method. It belongs to the orthorhombic system, space group Pnma with a = 5.1114, b = 10.4906 and c = 17.6172A. Good agreement between the experimental and calculated profile （Rp = 6.69%, Rwp = 9.73% and Rexp = 6.58%） was reached.
基金This work was supported by the National Natural Science Foundation of China (60378031) and Key Project of Science and Technology of Fujian Province (2001H1007)
文摘The spectral parameters of Nd^3＋ ions in Nd^3＋-doped NaGd（MoO4）2 crystal have been investigated based on Judd-Ofelt theory and obtained as follows： The intensity parameters Ωeff are Ω2 = 24.77×10^20, Ω4 = 7.31×10^-20 and Ω6 = 6.91×10^-20 cm^2. The radiative lifetime is 100 μs, and the quantum efficiency is 93.9%. The fluorescence branch ratios were calculated to be β1 = 0.441, β2 = 0.469,β3 = 0.086 and β4=0.004.
文摘通过共沉淀法合成了CuCr_(2)O_(4)黑色颜料。研究了沉淀剂(即尿素、氨水、氢氧化钠)对相组成和颜色性能的影响。同时,计算了以氨水和氢氧化钠为沉淀剂时CuCr_(2)O_(4)的结晶动力学和结晶机制。结果表明,由于两种离子(Cu^(2+)和Cr^(3+))的溶解度不同,沉淀过程的最佳pH值为7.5;由于产物中存在Cr2O3,尿素不适合作为沉淀剂。氨水作为沉淀剂时,CuCr_(2)O_(4)结晶的活化能为120.2 k J/mol,氢氧化钠作为沉淀剂时为141.3 k J/mol。CuCr_(2)O_(4)的结晶过程涉及成核和三维生长。较小的结晶活化能得到的CuCr_(2)O_(4)颗粒细小,分散均匀,呈色性能更优异。
基金supported by the National Natural Science Foundation of China(21407059,61308095)Science Development Project of Jilin Province,China(20130522071JH,20130102004JC,20140101160JC)~~
