A new dinuclear Y（3＋） coordination polymer{[Y2（H2O）2（C（14）H8O4）3（C（12）H8N2）2]·3 H2O}n （1, C（14）H8 O4 = 2,2＇-biphenyldicarboxylate, phen = 1,10-phenanthroline）, has been obtained by means of a mi...A new dinuclear Y（3＋） coordination polymer{[Y2（H2O）2（C（14）H8O4）3（C（12）H8N2）2]·3 H2O}n （1, C（14）H8 O4 = 2,2＇-biphenyldicarboxylate, phen = 1,10-phenanthroline）, has been obtained by means of a mixed-solvothermal method using ethylene glycol and water as solvent. The compound was characterized by elemental analysis, energy-dispersive X-ray spectroscopy（EDS）, IR spectrum and single-crystal X-ray diffraction. The results reveal that 1 belongs to monoclinic system, space group C2/c with a = 24.249（3）, b = 12.069（48）, c = 22.7304（08） A, β = 113.480（7）°, Z = 4, V = 6102（2） A3, Dc = 1.462 g·cm^-3, F（000） = 2728, μ = 1.968 mm（-1）, the final R = 0.0673, w R = 0.1508 and S = 1.085. Its structure can be regarded as a 1-D coordination polymer constructed by Y^3＋ cations, 2,2A-biphenyldicarboxylate, 1,10-phenanthroline and water molecules. The compound not only contains two kinds of organic ligands, but also exhibits interesting wave-like infinite chains and 18-MR windows with the diameter of 4.070（7）A × 5.326（9）A. The structure is further stabilized by means of O–H…O hydrogen bonds and π-π stacking interactions. Furthermore, the luminescent properties（including emission spectrum, CIE chromaticity coordinate and decay curve） of 1 were also investigated in the solid-state at room temperature.展开更多
Using the solution of general Korteweg-de Vries （KdV） equation, the solutions of the generalized variable coefficient Kadomtsev-Petviashvili （KP） equation are constructed, and then its new solitary wave-like solut...Using the solution of general Korteweg-de Vries （KdV） equation, the solutions of the generalized variable coefficient Kadomtsev-Petviashvili （KP） equation are constructed, and then its new solitary wave-like solution and Jacobi elliptic function solution are obtained.展开更多
The new technology of welding with impacting rotation is put forward to decrease the wave-like deformation of the TC4 thin plate weldment. The thermal stress and strain are vital to understand the mechanism of control...The new technology of welding with impacting rotation is put forward to decrease the wave-like deformation of the TC4 thin plate weldment. The thermal stress and strain are vital to understand the mechanism of controlling the wave-like deformation. In order to know the development of internal thermal stress and strain, finite element method is utilized for- the stress and strain are difficult to be investigated by experimental methods during the welding process. Temperature field, thermal stress evolution and distortion of thin plate are compared with the test results such as weld thermal cycle, residual stress sectioning measurement, and the deflection of the thin plate respectively. By the finite element analysis and test results verification, the meehaaism of the technology to control the wave-like deformation is brought forward, non-uniform thermal elastic strain between compressive plastic region and elastic extensive region is diminished by a certain amount of extensive plastic deformation by welding with impacting rotation process.展开更多
In this paper, Daftardar-Gejji and Jafari method is applied to solve fractional heat-like and wave-like models with variable coefficients. The method is proved for a variety of problems in one, two and three dimension...In this paper, Daftardar-Gejji and Jafari method is applied to solve fractional heat-like and wave-like models with variable coefficients. The method is proved for a variety of problems in one, two and three dimensional spaces where analytical approximate solutions are obtained. The examples are presented to show the efficiency and simplicity of this method.展开更多
We prove the global existence and uniqueness of classical solutions with small initial data and with wake-like decaying null infinity for the spherically symmetric Einstein-scalar-field equations with potential,where ...We prove the global existence and uniqueness of classical solutions with small initial data and with wake-like decaying null infinity for the spherically symmetric Einstein-scalar-field equations with potential,where the scalar potential V satisfies(1.13)and(1.14).展开更多
A charge density wave(CDW)ground state is observed in polycrystalline Cu_(2)Se below 125 K,which corresponds to an energy gap of 40.9 meV and an electron-phonon coupling constant of 0.6.Due to the polycrystalline stru...A charge density wave(CDW)ground state is observed in polycrystalline Cu_(2)Se below 125 K,which corresponds to an energy gap of 40.9 meV and an electron-phonon coupling constant of 0.6.Due to the polycrystalline structure,the Peierls transition process has been expanded to a wide temperature range from 90 K to 160 K.The Hall carrier concentration shows a continuous decrease from 2.1×10^(20)to 1.6×10^(20)cm^(-3)in the temperature range from 160 K to 90 K,while almost unchanged above 160 K and below 90 K.After entering the CDW ground state,a wave-like fluctuation was observed in theI-Vcurve near 50 K,which exhibits a periodic negative differential resistivity in an applied electric field due to the current.We also investigated the doping effect of Zn,Ni,and Te on the CDWground state.Both Zn and Ni doped Cu_(2)Se show a CDW character with increased energy gap and electron-phonon coupling constant,but no notable Peierls transition was observed in Te doped Cu_(2)Se.Similar wave-likeI-Vcurve was also seen in Cu_(1.98)Zn_(0.02)Se near 40 K.The regular fluctuation in the dcI-Vcurve was not magnetic field sensitive,but temperature and sample size sensitive.展开更多
By means of sn-function expansion method and cn-function expansion method, several kinds of explicit solutions to the coupled KdV equations with variable coefficients are obtained, which include three sets of periodic...By means of sn-function expansion method and cn-function expansion method, several kinds of explicit solutions to the coupled KdV equations with variable coefficients are obtained, which include three sets of periodic wave-like solutions. These solutions degenerate to solitary wave-like solutions at a certain limit. Some new solutions are presented.展开更多
基金supported by the National Natural Science Foundation of China(No.21601095)the Youth Project of Nanyang Normal University(No.QN2017065)the Opening Laboratory Project of Nanyang Normal University(No.SYKF2016075)
文摘A new dinuclear Y（3＋） coordination polymer{[Y2（H2O）2（C（14）H8O4）3（C（12）H8N2）2]·3 H2O}n （1, C（14）H8 O4 = 2,2＇-biphenyldicarboxylate, phen = 1,10-phenanthroline）, has been obtained by means of a mixed-solvothermal method using ethylene glycol and water as solvent. The compound was characterized by elemental analysis, energy-dispersive X-ray spectroscopy（EDS）, IR spectrum and single-crystal X-ray diffraction. The results reveal that 1 belongs to monoclinic system, space group C2/c with a = 24.249（3）, b = 12.069（48）, c = 22.7304（08） A, β = 113.480（7）°, Z = 4, V = 6102（2） A3, Dc = 1.462 g·cm^-3, F（000） = 2728, μ = 1.968 mm（-1）, the final R = 0.0673, w R = 0.1508 and S = 1.085. Its structure can be regarded as a 1-D coordination polymer constructed by Y^3＋ cations, 2,2A-biphenyldicarboxylate, 1,10-phenanthroline and water molecules. The compound not only contains two kinds of organic ligands, but also exhibits interesting wave-like infinite chains and 18-MR windows with the diameter of 4.070（7）A × 5.326（9）A. The structure is further stabilized by means of O–H…O hydrogen bonds and π-π stacking interactions. Furthermore, the luminescent properties（including emission spectrum, CIE chromaticity coordinate and decay curve） of 1 were also investigated in the solid-state at room temperature.
文摘Using the solution of general Korteweg-de Vries （KdV） equation, the solutions of the generalized variable coefficient Kadomtsev-Petviashvili （KP） equation are constructed, and then its new solitary wave-like solution and Jacobi elliptic function solution are obtained.
文摘The new technology of welding with impacting rotation is put forward to decrease the wave-like deformation of the TC4 thin plate weldment. The thermal stress and strain are vital to understand the mechanism of controlling the wave-like deformation. In order to know the development of internal thermal stress and strain, finite element method is utilized for- the stress and strain are difficult to be investigated by experimental methods during the welding process. Temperature field, thermal stress evolution and distortion of thin plate are compared with the test results such as weld thermal cycle, residual stress sectioning measurement, and the deflection of the thin plate respectively. By the finite element analysis and test results verification, the meehaaism of the technology to control the wave-like deformation is brought forward, non-uniform thermal elastic strain between compressive plastic region and elastic extensive region is diminished by a certain amount of extensive plastic deformation by welding with impacting rotation process.
文摘In this paper, Daftardar-Gejji and Jafari method is applied to solve fractional heat-like and wave-like models with variable coefficients. The method is proved for a variety of problems in one, two and three dimensional spaces where analytical approximate solutions are obtained. The examples are presented to show the efficiency and simplicity of this method.
基金supported by National Natural Science Foundation of China(Grant Nos.12301072 and 12326602)the Special Foundation for Junwu and Guangxi Ba Gui Scholars。
文摘We prove the global existence and uniqueness of classical solutions with small initial data and with wake-like decaying null infinity for the spherically symmetric Einstein-scalar-field equations with potential,where the scalar potential V satisfies(1.13)and(1.14).
基金This work is supported by“Solid State Solar-Thermal Energy Conversion Center(S3TEC)”an Energy Frontier Research Center funded by the U.S.Department of Energy,Office of Science,Office of Basic Energy Science under award number DE-SC0001299/DEFG02-09ER46577(Z.F.R.).C.O.wishes to thank Robert D.Farrell,S.J.for editing the MS and the Trustees of Boston College for their financial support.
文摘A charge density wave(CDW)ground state is observed in polycrystalline Cu_(2)Se below 125 K,which corresponds to an energy gap of 40.9 meV and an electron-phonon coupling constant of 0.6.Due to the polycrystalline structure,the Peierls transition process has been expanded to a wide temperature range from 90 K to 160 K.The Hall carrier concentration shows a continuous decrease from 2.1×10^(20)to 1.6×10^(20)cm^(-3)in the temperature range from 160 K to 90 K,while almost unchanged above 160 K and below 90 K.After entering the CDW ground state,a wave-like fluctuation was observed in theI-Vcurve near 50 K,which exhibits a periodic negative differential resistivity in an applied electric field due to the current.We also investigated the doping effect of Zn,Ni,and Te on the CDWground state.Both Zn and Ni doped Cu_(2)Se show a CDW character with increased energy gap and electron-phonon coupling constant,but no notable Peierls transition was observed in Te doped Cu_(2)Se.Similar wave-likeI-Vcurve was also seen in Cu_(1.98)Zn_(0.02)Se near 40 K.The regular fluctuation in the dcI-Vcurve was not magnetic field sensitive,but temperature and sample size sensitive.
文摘By means of sn-function expansion method and cn-function expansion method, several kinds of explicit solutions to the coupled KdV equations with variable coefficients are obtained, which include three sets of periodic wave-like solutions. These solutions degenerate to solitary wave-like solutions at a certain limit. Some new solutions are presented.
