The pale green powder of nickel L-threonate Ni（C4H7O5）2·2H2O was prepared from excess nickelous dihydroxycarbonate and L-threonic acid obtained by double decomposition reaction of calcium L-threonate with oxali...The pale green powder of nickel L-threonate Ni（C4H7O5）2·2H2O was prepared from excess nickelous dihydroxycarbonate and L-threonic acid obtained by double decomposition reaction of calcium L-threonate with oxalic acid at 80 ℃ for 2 h. The IR spectra indicated that Ni 2+ was in coordination with oxygen atom of the carboxyl group of L-threonic acid with coordination number of 4. The TG-DTG results showed the compound discomposes into NiO at 380 ℃ in nitrogen atmosphere. The constant volume combustion energy of the compound, ΔcE, determined by a precise rotating-bomb combustion calorimeter at 298.15 K, was （-3 515.22±1.97） kJ/mol. The standard enthalpy of combustion, ΔcH0m, and standard enthalpy of formation, ΔfH0m, were calculated to be -3 512.74±1.97 kJ/mol and -2 447.51±2.26 kJ/mol, respectively.展开更多
The mechanism of perovskite 0.1Pb(Mg1/2W1/2)O3-0.6Pb(Ni1/3Nb2/3)O3-0.3PbTiO3 (abbreviated PMW-PNN-PT) phase formation by Semichemical Method has been studied. The precursors were prepared by adding aqueous solution of...The mechanism of perovskite 0.1Pb(Mg1/2W1/2)O3-0.6Pb(Ni1/3Nb2/3)O3-0.3PbTiO3 (abbreviated PMW-PNN-PT) phase formation by Semichemical Method has been studied. The precursors were prepared by adding aqueous solution of Mg(Ac)2 and Ni(AC)2 rather than solid MgO and NiO to the alcoholic slurry of PbO, WO3, Nb2O5 and TiO2. The TG-DTG and DSC of the precursors and XRD analysis of the powders at various calcination temperature showed that the mechanism of this method was different from that of the conventional mixed oxide method. The aqueous Mg(Ac)2 and Ni(Ac)2 reacted with PbO to form basic lead acetate, basic magnesium acetate and basic nickel acetate and so on. With the increase of calcination temperature these basic salt decomposed to form nascent PbO, MgO and NiO, which improved the reactivity and distribution of PbO, MgO and NiO. In addition, the formation of PbWO4 and pyrochlore phase Pb3Nb2O8 in the process was in favor of the pervoskite PMW-PNN-PT phase formation. At the calcining temperature of 850 ℃, the perovskite phase reached 98%.展开更多
The mechanisms of Pb(Fe2/3W1/3)O3(PFW) powders with pure perovskite phase prep ared by semichemical method was proposed. The precursors were prepared by adding an aqueous Fe(NO3)3 solution rather than Fe2O3 to the alc...The mechanisms of Pb(Fe2/3W1/3)O3(PFW) powders with pure perovskite phase prep ared by semichemical method was proposed. The precursors were prepared by adding an aqueous Fe(NO3)3 solution rather than Fe2O3 to the alcoholic slurry of PbO a nd WO3. The TG-DTG-DTA and XRD analysis showed that the mechanism in this meth od was different from those of the known columbite precursor method or conventio nal mixed oxide method. Fe(NO3)3 reacted with PbO to form a intermediate of Pb2( NO3)2(OH)2 and Fe(OH)3 and/or Fe2O3 at milling and calcinations process. The act ivated PbO and Pb3O4 by the intermediate reacted with WO3 to form PbWO4, which r eacted directly with nascent-state Fe2O3 to transform into a pyrochlore structu re of Pb2FeWO6.5 at low calcining temperature. And then the pyrochlore phase pro gressively reacted with Fe2O3 to form perovskite PFW phase. Additionally, the ef fects of excess Fe2O3 on the formation of the perovskite PFW phase have been dis cussed.展开更多
合成了3,3-二硝基氮杂环丁烷(DNAZ)的酰基衍生物N-乙酰基-3,3-二硝基氮杂环丁烷(ADNAZ)和N-甲酰基-3,3-二硝基氮杂环丁烷(FDNAZ),并得到可用于X射线衍射的单晶.ADNAZ属于正交晶系,P212121空间群,晶胞参数a=0.6844(3)nm,b=0.6994(3)nm,c=...合成了3,3-二硝基氮杂环丁烷(DNAZ)的酰基衍生物N-乙酰基-3,3-二硝基氮杂环丁烷(ADNAZ)和N-甲酰基-3,3-二硝基氮杂环丁烷(FDNAZ),并得到可用于X射线衍射的单晶.ADNAZ属于正交晶系,P212121空间群,晶胞参数a=0.6844(3)nm,b=0.6994(3)nm,c=1.6948(6)nm,V=0.8112nm3,Z=4.FDNAZ属于单斜晶系,P21/c空间群,晶胞参数a=1.0322(4)nm,b=0.6054(2)nm,c=1.1268(4)nm,β=100.135(5)°,V=0.6932nm3,Z=4.用ADF(Amsterdam density functional)的DFT(Density functional theo-ry)方法对两个化合物进行了几何优化和频率计算,得到了其几何构型参数、原子Hirshfeld电荷、原子间Mayer键级和前线轨道能量及组成.理论分析表明,两个化合物中活性较大的原子均为酰基氧原子.展开更多
文摘The pale green powder of nickel L-threonate Ni（C4H7O5）2·2H2O was prepared from excess nickelous dihydroxycarbonate and L-threonic acid obtained by double decomposition reaction of calcium L-threonate with oxalic acid at 80 ℃ for 2 h. The IR spectra indicated that Ni 2+ was in coordination with oxygen atom of the carboxyl group of L-threonic acid with coordination number of 4. The TG-DTG results showed the compound discomposes into NiO at 380 ℃ in nitrogen atmosphere. The constant volume combustion energy of the compound, ΔcE, determined by a precise rotating-bomb combustion calorimeter at 298.15 K, was （-3 515.22±1.97） kJ/mol. The standard enthalpy of combustion, ΔcH0m, and standard enthalpy of formation, ΔfH0m, were calculated to be -3 512.74±1.97 kJ/mol and -2 447.51±2.26 kJ/mol, respectively.
文摘The mechanism of perovskite 0.1Pb(Mg1/2W1/2)O3-0.6Pb(Ni1/3Nb2/3)O3-0.3PbTiO3 (abbreviated PMW-PNN-PT) phase formation by Semichemical Method has been studied. The precursors were prepared by adding aqueous solution of Mg(Ac)2 and Ni(AC)2 rather than solid MgO and NiO to the alcoholic slurry of PbO, WO3, Nb2O5 and TiO2. The TG-DTG and DSC of the precursors and XRD analysis of the powders at various calcination temperature showed that the mechanism of this method was different from that of the conventional mixed oxide method. The aqueous Mg(Ac)2 and Ni(Ac)2 reacted with PbO to form basic lead acetate, basic magnesium acetate and basic nickel acetate and so on. With the increase of calcination temperature these basic salt decomposed to form nascent PbO, MgO and NiO, which improved the reactivity and distribution of PbO, MgO and NiO. In addition, the formation of PbWO4 and pyrochlore phase Pb3Nb2O8 in the process was in favor of the pervoskite PMW-PNN-PT phase formation. At the calcining temperature of 850 ℃, the perovskite phase reached 98%.
文摘The mechanisms of Pb(Fe2/3W1/3)O3(PFW) powders with pure perovskite phase prep ared by semichemical method was proposed. The precursors were prepared by adding an aqueous Fe(NO3)3 solution rather than Fe2O3 to the alcoholic slurry of PbO a nd WO3. The TG-DTG-DTA and XRD analysis showed that the mechanism in this meth od was different from those of the known columbite precursor method or conventio nal mixed oxide method. Fe(NO3)3 reacted with PbO to form a intermediate of Pb2( NO3)2(OH)2 and Fe(OH)3 and/or Fe2O3 at milling and calcinations process. The act ivated PbO and Pb3O4 by the intermediate reacted with WO3 to form PbWO4, which r eacted directly with nascent-state Fe2O3 to transform into a pyrochlore structu re of Pb2FeWO6.5 at low calcining temperature. And then the pyrochlore phase pro gressively reacted with Fe2O3 to form perovskite PFW phase. Additionally, the ef fects of excess Fe2O3 on the formation of the perovskite PFW phase have been dis cussed.
文摘合成了3,3-二硝基氮杂环丁烷(DNAZ)的酰基衍生物N-乙酰基-3,3-二硝基氮杂环丁烷(ADNAZ)和N-甲酰基-3,3-二硝基氮杂环丁烷(FDNAZ),并得到可用于X射线衍射的单晶.ADNAZ属于正交晶系,P212121空间群,晶胞参数a=0.6844(3)nm,b=0.6994(3)nm,c=1.6948(6)nm,V=0.8112nm3,Z=4.FDNAZ属于单斜晶系,P21/c空间群,晶胞参数a=1.0322(4)nm,b=0.6054(2)nm,c=1.1268(4)nm,β=100.135(5)°,V=0.6932nm3,Z=4.用ADF(Amsterdam density functional)的DFT(Density functional theo-ry)方法对两个化合物进行了几何优化和频率计算,得到了其几何构型参数、原子Hirshfeld电荷、原子间Mayer键级和前线轨道能量及组成.理论分析表明,两个化合物中活性较大的原子均为酰基氧原子.
