Effect of mechanical stress on magnetic properties of an exchange-biased ferromagnetic/antiferromagnetic bilayer deposited on a flexible substrate is investigated. The hysteresis loops with different magnitudes and or...Effect of mechanical stress on magnetic properties of an exchange-biased ferromagnetic/antiferromagnetic bilayer deposited on a flexible substrate is investigated. The hysteresis loops with different magnitudes and orientations of the stress can be classified into three types. The corresponding physical conditions for each type of the loop are deduced based on the principle of minimal energy. The equation of the critical stress is derived, which can judge whether the loops show hysteresis or not. Numerical calculations suggest that except for the magnitude of the mechanical stress, the relative orientation of the stress is also an important factor to tune the exchange bias effect.展开更多
Exploring, designing, and synthesizing novel organic field-effect transistor (OFET) materials have kept an important and hot issue in organic electronics. In the current work, the charge transport properties for 2,5...Exploring, designing, and synthesizing novel organic field-effect transistor (OFET) materials have kept an important and hot issue in organic electronics. In the current work, the charge transport properties for 2,5-di(cyanovinyl)thiophene/furan crystal associating two pentafluorophenyl units linked via the azomethine bond, CTE and CFE have been theoretically investigated by means of density functional theory (DFT) calculations coupled with the incoherent charge-hopping mechanism and the kinetic Monte Carlo simulation. Results show that these two compounds possess remarkably low-lying HOMO (-7.0 eV) and LUMO (-4.0 eV) levels, as well as large electron affinities (〉 3.0 eV), which indicate their high stability exposed to air as promising OFET materials. However, the ph value at room temperature (T = 300 K) is predicted to be 2.058x10^7 cm26Vl·s-1, and the is as low as 9.834^10-8 cm2-V-l.s-1 for CFT crystal. Meanwhile, these two values are 7.561 x 10-8 and 8.437 x 10-8 cm2.V-I.s-1 for the CFE crystal, respectively. Furthermore, the simulation of angle-dependent mobility in the a-b, a-c, and b-c crystal planes shows that the charge transport in CTE and CFE crystals is remarkably anisotropic, which maybe is helpful for the fabrication of high-performance OFET devices.展开更多
The completely unexplored LaP molecule is investigated by ab initio methods. Potential energy curves for the lowlying states of LaP are constructed by means of the diffusion Monte Carlo method combined with three diff...The completely unexplored LaP molecule is investigated by ab initio methods. Potential energy curves for the lowlying states of LaP are constructed by means of the diffusion Monte Carlo method combined with three different trial functions. Spectroscopic constants are also numerically derived and the ground state is assigned, looking forward to experimental comparisons. Moreover, variations of the permanent dipole moments as a function of the internuclear separation for the two lowest states of the diatomic LaP are studied and analyzed.展开更多
The reac dynamics on Ba+BrCH_3→BaBr+CH_3 has been investigated in the first proposed potential energy surface of the generalized LEPS type,using the quasiclassical trajectory method.In simulation of the conditions in...The reac dynamics on Ba+BrCH_3→BaBr+CH_3 has been investigated in the first proposed potential energy surface of the generalized LEPS type,using the quasiclassical trajectory method.In simulation of the conditions in molecular beam experiments,the results of the present study show significant effect of the reagent collision energy on the dynamics of the reaction,and are in good agreement with the experimental ones.展开更多
A photocycloaddition reaction of ethyl 1,4-diaryl-1,4-dihydropyridine-3-carboxylate for the construction of 3,9-diazatetraasteranes(Pr)and 3,9-diazatetracyclododecanes(P2)is reported for the first time.The types of re...A photocycloaddition reaction of ethyl 1,4-diaryl-1,4-dihydropyridine-3-carboxylate for the construction of 3,9-diazatetraasteranes(Pr)and 3,9-diazatetracyclododecanes(P2)is reported for the first time.The types of reaction product clearly differ with solvent,regardless of the irradiation wavelength.The difference in Pi and P2 lies in the second step of the intramolecular[2+2]photocyclization.In order to further investigate this phenomenon and gain a deeper understanding of the photochemical behavior of 1,4-dihydropyridines,DFT and TDDFT theoretical calculations are performed.The results provide a good explanation for the formation of 3,9-diazatetraasteranes and 3,9-diazatetracyclododecanes.展开更多
Core mode cutoff is a useful concept not only for a tapered single-core fiber(SCF) but also for a tapered multicore fiber(MCF) to realize cladding mode transmission. In this paper, cut-off conditions of either core mo...Core mode cutoff is a useful concept not only for a tapered single-core fiber(SCF) but also for a tapered multicore fiber(MCF) to realize cladding mode transmission. In this paper, cut-off conditions of either core mode for tapered SCFs or supermodes for MCFs are theoretically investigated. Rigorous analytical formulas are derived for the modes of SCF by a three-layer waveguide model, and an approximation formula of the cut-off condition is given for the LP01 mode. The supermodes of MCFs are analyzed by the coupling mode theory, and the cut-off condition is calculated by a numerical method. Simulation results show that the in-phase supermode of MCFs has a similar cut-off condition with that of SCF. Based on this property, a convenient approximate formula is given to estimate the cut-off condition of the in-phase supermode for tapered MCFs.展开更多
The problem of the laser-generated guided elastic waves in hollow cylinders is inves-tigated numerically by using the method of eigen-function expansion. The explicit expression of the transient waveform is given for ...The problem of the laser-generated guided elastic waves in hollow cylinders is inves-tigated numerically by using the method of eigen-function expansion. The explicit expression of the transient waveform is given for the case of the outer surface of the hollow cylinder beat axi-symmetrically by four laser pulses with same energy. The characteristics of the transient waveform are explained based on the dispersive relations.展开更多
According to the theory of phononic crystals, the hydraulic pipeline is designed to be a periodic structure composed of steel pipes and hoses to suppress the vibration of the hydraulic system with band gaps. We presen...According to the theory of phononic crystals, the hydraulic pipeline is designed to be a periodic structure composed of steel pipes and hoses to suppress the vibration of the hydraulic system with band gaps. We present theoretical and experimental investigations into the flexural vibration transfer properties of a high-pressure periodic pipe with the force on the inner pipe wall by oii pressure taken into consideration. The results show that the vibration attenuation of periodic pipe decreases along with the elevation of working pressure for the hydraulic system, and the band gaps in low frequency ranges move towards high frequency ranges. The periodic pipe has good vibration attenuation performance in the frequency range below 1000 Hz and the vibration of the hydraulic system is effectively suppressed. A11 the results are validated by experiment. The experimental results show a good agreement with the numerical calculations, thus the flexural vibration transfer properties of the high- pressure periodic pipe can be precisely calculated by taking the fluid structure interaction between the pipe and oil into consideration. This study provides an effective way for the vibration control of the hydraulic system.展开更多
Two transition metal dinuclear complexes of [Mn2(OOCC6H4SSC6H4COO)- (Phen)2(H20)]n 1 and [CuE(OOCC6H4S)2(Phen)2] 2 were hydrothermally synthesized by the reaction of equivalent metal dichloride with 2,2'-di...Two transition metal dinuclear complexes of [Mn2(OOCC6H4SSC6H4COO)- (Phen)2(H20)]n 1 and [CuE(OOCC6H4S)2(Phen)2] 2 were hydrothermally synthesized by the reaction of equivalent metal dichloride with 2,2'-dithiobis(benzoic acid) (HE-DTBB). Structure analysis indicates that each Mn2+ ion in I is coordinated by one chelate phen ligand, one bridging water molecule and three DTBB ligands forming Mn2+ dinuclear units which are further linked into one-dimensional chain by DTBB ligand. Under similar reaction conditions, the 2,2'-dithio- his(benzoic acid) ligand undergoes thiol reduction to form 2-mercaptobenzoic (H-2-MBA) in 2 where two Cu2+ ions are coordinated by phen and MBA ligands only constructing a dinuclear unit.展开更多
基金Supported by the Youth Science Foundation of Shanxi Province under Grant No 2013021010-3the National Natural Science Foundation of China under Grant Nos 61434002 and 11404202
文摘Effect of mechanical stress on magnetic properties of an exchange-biased ferromagnetic/antiferromagnetic bilayer deposited on a flexible substrate is investigated. The hysteresis loops with different magnitudes and orientations of the stress can be classified into three types. The corresponding physical conditions for each type of the loop are deduced based on the principle of minimal energy. The equation of the critical stress is derived, which can judge whether the loops show hysteresis or not. Numerical calculations suggest that except for the magnitude of the mechanical stress, the relative orientation of the stress is also an important factor to tune the exchange bias effect.
基金supported by the National Natural Science Foundation of China(No.21373132,21173138,21502109)the Doctor Research start foundation of Shaanxi University of Technology(No.SLGKYQD2-13,SLGKYQD2-10,SLGQD14-10)
文摘Exploring, designing, and synthesizing novel organic field-effect transistor (OFET) materials have kept an important and hot issue in organic electronics. In the current work, the charge transport properties for 2,5-di(cyanovinyl)thiophene/furan crystal associating two pentafluorophenyl units linked via the azomethine bond, CTE and CFE have been theoretically investigated by means of density functional theory (DFT) calculations coupled with the incoherent charge-hopping mechanism and the kinetic Monte Carlo simulation. Results show that these two compounds possess remarkably low-lying HOMO (-7.0 eV) and LUMO (-4.0 eV) levels, as well as large electron affinities (〉 3.0 eV), which indicate their high stability exposed to air as promising OFET materials. However, the ph value at room temperature (T = 300 K) is predicted to be 2.058x10^7 cm26Vl·s-1, and the is as low as 9.834^10-8 cm2-V-l.s-1 for CFT crystal. Meanwhile, these two values are 7.561 x 10-8 and 8.437 x 10-8 cm2.V-I.s-1 for the CFE crystal, respectively. Furthermore, the simulation of angle-dependent mobility in the a-b, a-c, and b-c crystal planes shows that the charge transport in CTE and CFE crystals is remarkably anisotropic, which maybe is helpful for the fabrication of high-performance OFET devices.
文摘The completely unexplored LaP molecule is investigated by ab initio methods. Potential energy curves for the lowlying states of LaP are constructed by means of the diffusion Monte Carlo method combined with three different trial functions. Spectroscopic constants are also numerically derived and the ground state is assigned, looking forward to experimental comparisons. Moreover, variations of the permanent dipole moments as a function of the internuclear separation for the two lowest states of the diatomic LaP are studied and analyzed.
文摘The reac dynamics on Ba+BrCH_3→BaBr+CH_3 has been investigated in the first proposed potential energy surface of the generalized LEPS type,using the quasiclassical trajectory method.In simulation of the conditions in molecular beam experiments,the results of the present study show significant effect of the reagent collision energy on the dynamics of the reaction,and are in good agreement with the experimental ones.
基金supported by the Beijing Natural Science Foundation(No.2192004).
文摘A photocycloaddition reaction of ethyl 1,4-diaryl-1,4-dihydropyridine-3-carboxylate for the construction of 3,9-diazatetraasteranes(Pr)and 3,9-diazatetracyclododecanes(P2)is reported for the first time.The types of reaction product clearly differ with solvent,regardless of the irradiation wavelength.The difference in Pi and P2 lies in the second step of the intramolecular[2+2]photocyclization.In order to further investigate this phenomenon and gain a deeper understanding of the photochemical behavior of 1,4-dihydropyridines,DFT and TDDFT theoretical calculations are performed.The results provide a good explanation for the formation of 3,9-diazatetraasteranes and 3,9-diazatetracyclododecanes.
文摘Core mode cutoff is a useful concept not only for a tapered single-core fiber(SCF) but also for a tapered multicore fiber(MCF) to realize cladding mode transmission. In this paper, cut-off conditions of either core mode for tapered SCFs or supermodes for MCFs are theoretically investigated. Rigorous analytical formulas are derived for the modes of SCF by a three-layer waveguide model, and an approximation formula of the cut-off condition is given for the LP01 mode. The supermodes of MCFs are analyzed by the coupling mode theory, and the cut-off condition is calculated by a numerical method. Simulation results show that the in-phase supermode of MCFs has a similar cut-off condition with that of SCF. Based on this property, a convenient approximate formula is given to estimate the cut-off condition of the in-phase supermode for tapered MCFs.
基金the Doctoral Foundation of Education Ministry of China(GrantNo.1999028432) and the Natural Science Foundation of Jiangsu Province(Grant No.BK97031).
文摘The problem of the laser-generated guided elastic waves in hollow cylinders is inves-tigated numerically by using the method of eigen-function expansion. The explicit expression of the transient waveform is given for the case of the outer surface of the hollow cylinder beat axi-symmetrically by four laser pulses with same energy. The characteristics of the transient waveform are explained based on the dispersive relations.
文摘According to the theory of phononic crystals, the hydraulic pipeline is designed to be a periodic structure composed of steel pipes and hoses to suppress the vibration of the hydraulic system with band gaps. We present theoretical and experimental investigations into the flexural vibration transfer properties of a high-pressure periodic pipe with the force on the inner pipe wall by oii pressure taken into consideration. The results show that the vibration attenuation of periodic pipe decreases along with the elevation of working pressure for the hydraulic system, and the band gaps in low frequency ranges move towards high frequency ranges. The periodic pipe has good vibration attenuation performance in the frequency range below 1000 Hz and the vibration of the hydraulic system is effectively suppressed. A11 the results are validated by experiment. The experimental results show a good agreement with the numerical calculations, thus the flexural vibration transfer properties of the high- pressure periodic pipe can be precisely calculated by taking the fluid structure interaction between the pipe and oil into consideration. This study provides an effective way for the vibration control of the hydraulic system.
基金Supported by the Natural Science Foundation of Henan Province (No. 0611011900)
文摘Two transition metal dinuclear complexes of [Mn2(OOCC6H4SSC6H4COO)- (Phen)2(H20)]n 1 and [CuE(OOCC6H4S)2(Phen)2] 2 were hydrothermally synthesized by the reaction of equivalent metal dichloride with 2,2'-dithiobis(benzoic acid) (HE-DTBB). Structure analysis indicates that each Mn2+ ion in I is coordinated by one chelate phen ligand, one bridging water molecule and three DTBB ligands forming Mn2+ dinuclear units which are further linked into one-dimensional chain by DTBB ligand. Under similar reaction conditions, the 2,2'-dithio- his(benzoic acid) ligand undergoes thiol reduction to form 2-mercaptobenzoic (H-2-MBA) in 2 where two Cu2+ ions are coordinated by phen and MBA ligands only constructing a dinuclear unit.