The glasses of 59 5H 3BO 3 40XF n 0 5Eu 2O 3 (X=Ca, Mg, Y, Pb, n =2 or 3) were prepared. The measurement of phonon sideband was performed. The higher energy range of phonon sideband spectra was fitted ...The glasses of 59 5H 3BO 3 40XF n 0 5Eu 2O 3 (X=Ca, Mg, Y, Pb, n =2 or 3) were prepared. The measurement of phonon sideband was performed. The higher energy range of phonon sideband spectra was fitted by Gaussian function, and the electron phonon coupling constant was calculated. The decreasing order of electron phonon coupling constant is from CaF 2, YF 3, MgF 2 to PbF 2, and the phonon sideband spectra are coincide with Raman scattering spectra.展开更多
The effects of the addition of H3BO3 on the microstructure, phase formation, and microwave dielectric properties of （Zn0.TMg0.3）TiO3 ceramics sintered at temperatures ranging from 890 ℃ to 950 ℃ are investigated. ...The effects of the addition of H3BO3 on the microstructure, phase formation, and microwave dielectric properties of （Zn0.TMg0.3）TiO3 ceramics sintered at temperatures ranging from 890 ℃ to 950 ℃ are investigated. H3BO3 as a sintering agent can effectively lower the sintering temperature of ZMT ceramics below 950 ℃due to the liquid-phase effect. The microwave dielectric properties are found to strongly correlate with the amount of H3BO3. With the increase in H3BO3 content, the dielectric constant （er） monotonically increases, but the quality factor （Q x f） reaches a maximum at 1 wt% H3BO3, and the apparent density of ZMT ceramics with H3BO3〉 1 wt% gradually decreases. At 950 ℃, the ZMT ceramics with 1% H3BO3 exhibit excellent microwave dielectric properties： er = 19.8, and Q x f -- 43800 GHz （8.94 GHz）.展开更多
The title compound 4-(4-chlorophenyl)-6-methyl-5-methoxy-caronyl-3,4-dihydro- pyrimidin-2(H)-one has been synthesized by the reaction of 4-chlorobenzaldehyde, methyl acetoa- cetate and urea using H3BO3 as a catalyst...The title compound 4-(4-chlorophenyl)-6-methyl-5-methoxy-caronyl-3,4-dihydro- pyrimidin-2(H)-one has been synthesized by the reaction of 4-chlorobenzaldehyde, methyl acetoa- cetate and urea using H3BO3 as a catalyst under microwave irradiation. Its structure was charac- terized by X-ray single-crystal diffraction techniques with the following data: triclinic, space group P1, a = 5.4513(4), b = 7.619(1), c = 16.118(4) ?, α = 80.42(1), β = 83.43(1), γ = 79.29(1)°, V = 646.19(19) ?3, Mr = 280.70, μ(MoKα) = 0.301 mm-1, Z = 2 and Dc = 1.443 g/cm3. In the molecule the pyrimidine ring is of boat conformation.展开更多
文摘The glasses of 59 5H 3BO 3 40XF n 0 5Eu 2O 3 (X=Ca, Mg, Y, Pb, n =2 or 3) were prepared. The measurement of phonon sideband was performed. The higher energy range of phonon sideband spectra was fitted by Gaussian function, and the electron phonon coupling constant was calculated. The decreasing order of electron phonon coupling constant is from CaF 2, YF 3, MgF 2 to PbF 2, and the phonon sideband spectra are coincide with Raman scattering spectra.
基金supported by the National Natural Science Foundation of China(Grant Nos.61171047,51132003,51072029,and 61271038)the Program for New Century Excellent Talents in Universitythe Fund from the Science and Technology Department of Sichuan Province,China
文摘The effects of the addition of H3BO3 on the microstructure, phase formation, and microwave dielectric properties of （Zn0.TMg0.3）TiO3 ceramics sintered at temperatures ranging from 890 ℃ to 950 ℃ are investigated. H3BO3 as a sintering agent can effectively lower the sintering temperature of ZMT ceramics below 950 ℃due to the liquid-phase effect. The microwave dielectric properties are found to strongly correlate with the amount of H3BO3. With the increase in H3BO3 content, the dielectric constant （er） monotonically increases, but the quality factor （Q x f） reaches a maximum at 1 wt% H3BO3, and the apparent density of ZMT ceramics with H3BO3〉 1 wt% gradually decreases. At 950 ℃, the ZMT ceramics with 1% H3BO3 exhibit excellent microwave dielectric properties： er = 19.8, and Q x f -- 43800 GHz （8.94 GHz）.
基金This work was supported by the NNSFC (No. 20372057) Natural Science Foundation of Jiangsu Province (No. BK2001142)+2 种基金 the Open Foundation of Key Laboratory of Organic Synthesis of Jiangsu Province College of Chemistry and Chemical Engineering Su
文摘The title compound 4-(4-chlorophenyl)-6-methyl-5-methoxy-caronyl-3,4-dihydro- pyrimidin-2(H)-one has been synthesized by the reaction of 4-chlorobenzaldehyde, methyl acetoa- cetate and urea using H3BO3 as a catalyst under microwave irradiation. Its structure was charac- terized by X-ray single-crystal diffraction techniques with the following data: triclinic, space group P1, a = 5.4513(4), b = 7.619(1), c = 16.118(4) ?, α = 80.42(1), β = 83.43(1), γ = 79.29(1)°, V = 646.19(19) ?3, Mr = 280.70, μ(MoKα) = 0.301 mm-1, Z = 2 and Dc = 1.443 g/cm3. In the molecule the pyrimidine ring is of boat conformation.
