A new energetic compound based on the tetrazole-1-acetic acid （tza） and potassium（I） salt, K2（tza）2（H2O）, was synthesized and characterized by elemental analysis and FT-IR spectrum. Its crystal structure was d...A new energetic compound based on the tetrazole-1-acetic acid （tza） and potassium（I） salt, K2（tza）2（H2O）, was synthesized and characterized by elemental analysis and FT-IR spectrum. Its crystal structure was determined by single-crystal X-ray diffraction analysis. The results show that the crystal belongs to the orthorhombic system, space group Pna21 with a = 1.11972（17） nm, b = 0.46647（7） nm, c = 2.5158（4） nm, V = 1.3140（3） nm3, K2C6H8N8O5, Mr = 350.40 g·mol-1, Dc = 1.771 g·cm^-3, μ（MoKα） = 0.759 mm^-1, F（000） = 712, Z = 4, R = 0.023 and wR = 0.0527 for 2961 observed reflections （I 〉 2σ（I））. The K（I） cation is six-coordinated with four O atoms from three carboxylate groups, one O atom from one H2O molecule and one N atom from tetrazolyl ring, in which each tza is coordinated in a tridentate chelating bridging coordination mode. The thermal decomposition mechanism of the title complex was studied by DSC and TG-DTG techniques. Under nitrogen atmosphere at a heating rate of 10 K·min-1, the thermal decomposition of the complex contains one main exothermic process between 191.7 and 243.8 ℃ in the DSC curve. Its combustion heat was mensurated by oxygen bomb calorimetry. The non-isothermal kinetics parameters were calculated by the Kissinger＇s method and Ozawa-Doyle＇s method, respectively. The sensitivity properties of K2（tza）2（H2O） were also determined with standard methods, which was very sensitive to flame.展开更多
A new complex of magnesium with tetrazole-l-acetic acid （tza） has been synthe- sized and characterized by elemental analysis and FT-IR spectrum. Single-crystal X-ray diffraction analysis determined the molecular for...A new complex of magnesium with tetrazole-l-acetic acid （tza） has been synthe- sized and characterized by elemental analysis and FT-IR spectrum. Single-crystal X-ray diffraction analysis determined the molecular formula as Mg（tza）2（H20）4. The crystal belongs to the triclinic system with Pi space group, and a = 6.133（2）, b = 6.488（2）, c = 10.0127（7） A, a = 77.282（10）, fl = 91.558（1）, ）, = 76.002（8）°, Y = 349.0（2）A3, Z = 1, C6HI4MgNsOs, Mr = 350.56, Dc = 1.668 g.cm-3, F（000） = 182,μ = 0.189, S = 1.000, the final R = 0.0294 and wR = 0.0785 for 1128 observed reflections with I 〉 20-（I）. In this molecule, the tza ion exhibits an infrequent monodentate coordination mode. The magnesium center is hexa-coordinated to a slightly distorted octahedral configuration by six oxygen atoms from two tza ligands and four coordinated water molecules. DSC and TG-DTG analyses were applied to assess the thermal decomposition behavior. The kinetic parameters of the exothermal peak were calculated by non-isothermal reaction kinetics. The values of critical temperature of thermal explosion, △S≠, △H≠ and △G^≠, were obtained as 596 K, -42.25 J mo1^-1 K^-1, 296.43 kJ mol^-1 and 323.53 kJ mol1, respectively.展开更多
A theoretical treatment of the scattering of anti-plane shear(SH) waves is provided by a single crack in an unbounded transversely isotropic electro-magneto-elastic medium. Based on the differential equations of equil...A theoretical treatment of the scattering of anti-plane shear(SH) waves is provided by a single crack in an unbounded transversely isotropic electro-magneto-elastic medium. Based on the differential equations of equilibrium, electric displacement and magnetic induction intensity differential equations, the governing equations for SH waves were obtained. By means of a linear transform, the governing equations were reduced to one Helmholtz and two Laplace equations. The Cauchy singular integral equations were gained by making use of Fourier transform and adopting electro-magneto impermeable boundary conditions. The closed form expression for the resulting stress intensity factor at the crack was achieved by solving the appropriate singular integral equations using Chebyshev polynomial. Typical examples are provided to show the loading frequency upon the local stress fields around the crack tips. The study reveals the importance of the electro-magneto-mechanical coupling terms upon the resulting dynamic stress intensity factor.展开更多
基金supported by National Key Laboratory of Science and Technology on Combustion and Explosion (9140C3503010904)the State Key Laboratory of Explosion Science and Technology (No. YBK T 10-05 and ZDKT10-01b)Program for New Century Excellent Talents in University (NCET-10-0051) (CNET-09-0051)
文摘A new energetic compound based on the tetrazole-1-acetic acid （tza） and potassium（I） salt, K2（tza）2（H2O）, was synthesized and characterized by elemental analysis and FT-IR spectrum. Its crystal structure was determined by single-crystal X-ray diffraction analysis. The results show that the crystal belongs to the orthorhombic system, space group Pna21 with a = 1.11972（17） nm, b = 0.46647（7） nm, c = 2.5158（4） nm, V = 1.3140（3） nm3, K2C6H8N8O5, Mr = 350.40 g·mol-1, Dc = 1.771 g·cm^-3, μ（MoKα） = 0.759 mm^-1, F（000） = 712, Z = 4, R = 0.023 and wR = 0.0527 for 2961 observed reflections （I 〉 2σ（I））. The K（I） cation is six-coordinated with four O atoms from three carboxylate groups, one O atom from one H2O molecule and one N atom from tetrazolyl ring, in which each tza is coordinated in a tridentate chelating bridging coordination mode. The thermal decomposition mechanism of the title complex was studied by DSC and TG-DTG techniques. Under nitrogen atmosphere at a heating rate of 10 K·min-1, the thermal decomposition of the complex contains one main exothermic process between 191.7 and 243.8 ℃ in the DSC curve. Its combustion heat was mensurated by oxygen bomb calorimetry. The non-isothermal kinetics parameters were calculated by the Kissinger＇s method and Ozawa-Doyle＇s method, respectively. The sensitivity properties of K2（tza）2（H2O） were also determined with standard methods, which was very sensitive to flame.
基金Financial support to this work by the National Natural Science Foundation of China (No.10776002, 20911120033)the Project of State Key Laboratory of Science and Technology (ZDKT08-01, YBKT10-03)Doctoral Candidate Innovation Research Support Program by Science & Technology Review (kjdb201001-2)
文摘A new complex of magnesium with tetrazole-l-acetic acid （tza） has been synthe- sized and characterized by elemental analysis and FT-IR spectrum. Single-crystal X-ray diffraction analysis determined the molecular formula as Mg（tza）2（H20）4. The crystal belongs to the triclinic system with Pi space group, and a = 6.133（2）, b = 6.488（2）, c = 10.0127（7） A, a = 77.282（10）, fl = 91.558（1）, ）, = 76.002（8）°, Y = 349.0（2）A3, Z = 1, C6HI4MgNsOs, Mr = 350.56, Dc = 1.668 g.cm-3, F（000） = 182,μ = 0.189, S = 1.000, the final R = 0.0294 and wR = 0.0785 for 1128 observed reflections with I 〉 20-（I）. In this molecule, the tza ion exhibits an infrequent monodentate coordination mode. The magnesium center is hexa-coordinated to a slightly distorted octahedral configuration by six oxygen atoms from two tza ligands and four coordinated water molecules. DSC and TG-DTG analyses were applied to assess the thermal decomposition behavior. The kinetic parameters of the exothermal peak were calculated by non-isothermal reaction kinetics. The values of critical temperature of thermal explosion, △S≠, △H≠ and △G^≠, were obtained as 596 K, -42.25 J mo1^-1 K^-1, 296.43 kJ mol^-1 and 323.53 kJ mol1, respectively.
文摘A theoretical treatment of the scattering of anti-plane shear(SH) waves is provided by a single crack in an unbounded transversely isotropic electro-magneto-elastic medium. Based on the differential equations of equilibrium, electric displacement and magnetic induction intensity differential equations, the governing equations for SH waves were obtained. By means of a linear transform, the governing equations were reduced to one Helmholtz and two Laplace equations. The Cauchy singular integral equations were gained by making use of Fourier transform and adopting electro-magneto impermeable boundary conditions. The closed form expression for the resulting stress intensity factor at the crack was achieved by solving the appropriate singular integral equations using Chebyshev polynomial. Typical examples are provided to show the loading frequency upon the local stress fields around the crack tips. The study reveals the importance of the electro-magneto-mechanical coupling terms upon the resulting dynamic stress intensity factor.
