五员杂环及衍生物是重要的工业原料,有些具有重要的生理作用。为了探讨此类化合物结构特点、化学位移与活性之间的关系,本文采用密度泛函B3LYP和从头计算ab initio HF、MP2方法研究了呋喃、吡咯、噻吩的几何构型,用TD-DFT方法对分子的...五员杂环及衍生物是重要的工业原料,有些具有重要的生理作用。为了探讨此类化合物结构特点、化学位移与活性之间的关系,本文采用密度泛函B3LYP和从头计算ab initio HF、MP2方法研究了呋喃、吡咯、噻吩的几何构型,用TD-DFT方法对分子的电子光谱进行了计算,运用GAIO-HF计算了分子的化学位移,并将计算数据与实验值进行比较。结果表明：(1)选用MP2对此类化合物键长键角更为适宜；(2)三种化合物电子光谱的最大吸收波长很接近,溶液的计算值优于气相的；(3)分子的化学位移与反应活性有密切联系：化合物α位氢原子的δ_H值愈小,该化合物亲电取代反应活性愈高；同一杂环分子,氢原子的δ_H值愈小,该位置的亲电取代反应活性愈高。展开更多
We delve into the phenomenon of high-order harmonic generation within a helium atom under the influence of a plasmon-assisted shaping pulse.Our findings reveal an intriguing manipulation of the frequency peak position...We delve into the phenomenon of high-order harmonic generation within a helium atom under the influence of a plasmon-assisted shaping pulse.Our findings reveal an intriguing manipulation of the frequency peak position in the harmonic emission by adjusting the absolute phase parameter within the frequency domain of the shaping pulse.This phenomenon holds potential significance for experimental setups necessitating precisely tuned single harmonics.Notably,we observe a modulated shift in the created harmonic photon energy,spanning an impressive range of 1.2 eV.This frequency peak shift is rooted in the asymmetry exhibited by the rising and falling edges of the laser pulse,directly influencing the position of the peak frequency emission.Our study quantifies the dependence of this tuning range and the asymmetry of the laser pulse,offering valuable insights into the underlying mechanisms driving this phenomenon.Furthermore,our investigation uncovers the emergence of semi-integer order harmonics as the phase parameter is altered.We attribute this discovery to the intricate interference between harmonics generated by the primary and secondary return cores.This observation introduces an innovative approach for generating semi-integer order harmonics,thus expanding our understanding of high-order harmonic generation.Ultimately,our work contributes to the broader comprehension of complex phenomena in laser-matter interactions and provides a foundation for harnessing these effects in various applications,particularly those involving precise spectral control and the generation of unique harmonic patterns.展开更多
Equilibrium geometries of 16 possible isomers for C74（BN）2 were studied by INDO series of methods, to indicate that the most stable three geometries are those where boron and nitrogen atoms substitute carbon atoms l...Equilibrium geometries of 16 possible isomers for C74（BN）2 were studied by INDO series of methods, to indicate that the most stable three geometries are those where boron and nitrogen atoms substitute carbon atoms located at the same hexagon near the longest axis of C78 （C2v） to form B-N-B-N unit. Electronic spectra of C74（BN）2 were investigated with INDO/CIS method. The reason for the red shift of UV absorptions for C74（BN）2 compared with those of C78 （C2v） was discussed. IR spectra for 9,8,28,29-C74（BN）2 and 28,29,30,31-C74（BN）2 were calculated on the basis of AM1 geometries.展开更多
We systematically investigate the optical properties of the InP1-xBix ternary alloys with 0≤x≤2.46%,by using high resolution polarized Raman scattering measurement.Both InP-like and InBi-like optical vibration modes...We systematically investigate the optical properties of the InP1-xBix ternary alloys with 0≤x≤2.46%,by using high resolution polarized Raman scattering measurement.Both InP-like and InBi-like optical vibration modes（LO） are identified in all the samples,suggesting that most of the Bi-atoms are incorporated into the lattice sites to substitute Patoms.And the intensity of the InBi-like Raman mode is positively proportional to the Bi-content.Linear red-shift of the InP-like longitudinal optical vibration mode is observed to be 1.1 cm-1/Bi%,while that of the InP-like optical vibration overtone（2LO） is nearly doubled.In addition,through comparing the（XX） and Z（XY） Raman spectra,longitudinaloptical-plasmon-coupled（LOPC） modes are identified in all the samples,and their intensities are found to be proportional to the electron concentrations.展开更多
Rotation symmetric function was presented by Pieprzyk. The algebraic configuration of rotation symmetric（RotS） function is special. For a Rots n variables function f（x1, x2, …, xn） we have f（ρn^k （x1, x2, …x...Rotation symmetric function was presented by Pieprzyk. The algebraic configuration of rotation symmetric（RotS） function is special. For a Rots n variables function f（x1, x2, …, xn） we have f（ρn^k （x1, x2, …xn））=f（x1, x2, …, xn） for k=0, 1, …, n-1. In this paper, useing probability method we find that when the parameters of RotS function is under circular translation of indices, its walsh spectrum is invariant. And we prove the result is both sufficient and necessary.展开更多
文摘五员杂环及衍生物是重要的工业原料,有些具有重要的生理作用。为了探讨此类化合物结构特点、化学位移与活性之间的关系,本文采用密度泛函B3LYP和从头计算ab initio HF、MP2方法研究了呋喃、吡咯、噻吩的几何构型,用TD-DFT方法对分子的电子光谱进行了计算,运用GAIO-HF计算了分子的化学位移,并将计算数据与实验值进行比较。结果表明：(1)选用MP2对此类化合物键长键角更为适宜；(2)三种化合物电子光谱的最大吸收波长很接近,溶液的计算值优于气相的；(3)分子的化学位移与反应活性有密切联系：化合物α位氢原子的δ_H值愈小,该化合物亲电取代反应活性愈高；同一杂环分子,氢原子的δ_H值愈小,该位置的亲电取代反应活性愈高。
基金This project was supported by the National Key Research and Development Program of China(Grant Nos.2022YFE134200 and 2019YFA0307700)the National Natural Science Foundation of China(Grant Nos.11604119,12104177,11904192,12074145,and 11704147)the Fundamental Research Funds for the Central Universities(Grant Nos.GK202207012 and QCYRCXM-2022-241).
文摘We delve into the phenomenon of high-order harmonic generation within a helium atom under the influence of a plasmon-assisted shaping pulse.Our findings reveal an intriguing manipulation of the frequency peak position in the harmonic emission by adjusting the absolute phase parameter within the frequency domain of the shaping pulse.This phenomenon holds potential significance for experimental setups necessitating precisely tuned single harmonics.Notably,we observe a modulated shift in the created harmonic photon energy,spanning an impressive range of 1.2 eV.This frequency peak shift is rooted in the asymmetry exhibited by the rising and falling edges of the laser pulse,directly influencing the position of the peak frequency emission.Our study quantifies the dependence of this tuning range and the asymmetry of the laser pulse,offering valuable insights into the underlying mechanisms driving this phenomenon.Furthermore,our investigation uncovers the emergence of semi-integer order harmonics as the phase parameter is altered.We attribute this discovery to the intricate interference between harmonics generated by the primary and secondary return cores.This observation introduces an innovative approach for generating semi-integer order harmonics,thus expanding our understanding of high-order harmonic generation.Ultimately,our work contributes to the broader comprehension of complex phenomena in laser-matter interactions and provides a foundation for harnessing these effects in various applications,particularly those involving precise spectral control and the generation of unique harmonic patterns.
文摘Equilibrium geometries of 16 possible isomers for C74（BN）2 were studied by INDO series of methods, to indicate that the most stable three geometries are those where boron and nitrogen atoms substitute carbon atoms located at the same hexagon near the longest axis of C78 （C2v） to form B-N-B-N unit. Electronic spectra of C74（BN）2 were investigated with INDO/CIS method. The reason for the red shift of UV absorptions for C74（BN）2 compared with those of C78 （C2v） was discussed. IR spectra for 9,8,28,29-C74（BN）2 and 28,29,30,31-C74（BN）2 were calculated on the basis of AM1 geometries.
基金Project supported by the National Basic Research Program of China(Grant No.2014CB643903)the National Natural Science Foundation of China(Grant Nos.61225021,11474272.and 11174272)
文摘We systematically investigate the optical properties of the InP1-xBix ternary alloys with 0≤x≤2.46%,by using high resolution polarized Raman scattering measurement.Both InP-like and InBi-like optical vibration modes（LO） are identified in all the samples,suggesting that most of the Bi-atoms are incorporated into the lattice sites to substitute Patoms.And the intensity of the InBi-like Raman mode is positively proportional to the Bi-content.Linear red-shift of the InP-like longitudinal optical vibration mode is observed to be 1.1 cm-1/Bi%,while that of the InP-like optical vibration overtone（2LO） is nearly doubled.In addition,through comparing the（XX） and Z（XY） Raman spectra,longitudinaloptical-plasmon-coupled（LOPC） modes are identified in all the samples,and their intensities are found to be proportional to the electron concentrations.
基金Supported by the National Natural ScienceFoundation of China (90104035)
文摘Rotation symmetric function was presented by Pieprzyk. The algebraic configuration of rotation symmetric（RotS） function is special. For a Rots n variables function f（x1, x2, …, xn） we have f（ρn^k （x1, x2, …xn））=f（x1, x2, …, xn） for k=0, 1, …, n-1. In this paper, useing probability method we find that when the parameters of RotS function is under circular translation of indices, its walsh spectrum is invariant. And we prove the result is both sufficient and necessary.
