Oxalyl chloride is a highly toxic and caustic substance, which widely exists in human production and life as a kind of volatile organic compound. Based on the density functional theory B3 LYP at 6-311++G(d, p) level, ...Oxalyl chloride is a highly toxic and caustic substance, which widely exists in human production and life as a kind of volatile organic compound. Based on the density functional theory B3 LYP at 6-311++G(d, p) level, the influences of external electric field on the bond length, bond energy, dipole moment and dissociation mechanism are optimized. The results indicate that the C_1–Cl_3 bond length increases while the C_4–Cl_6 bond decreases. At the same time, the carbon-carbon bond length gradually increases with the increase of electric field. The total energy decreases while the dipole moment gradually increases with the increase of electric field. In the infrared spectra, the vibration frequency of the carbon-chlorine(C_4–Cl_6) bond decreases while the vibration frequency of the carbon-oxygen bond increases. In the ultraviolet-visible spectra, the wavelength of the strongest absorption peak increases as the external electric field increases and shows an observable red shift phenomenon. Additionally, single point energies of oxalyl chloride along the carbon-carbon bond are scanned with the equation-of-motion coupled cluster method restricted to single and double excitations(EOM-CCSD) method and the potential energy curves under different external electric fields are obtained. The dissociation barrier in potential energy curve decreases because of the breakage of carbon-carbon bond with the increase of external electric field. These results provide reference for further researches on the properties of oxalyl chloride and offer a theoretical basis for the study of oxalyl chloride degradation.展开更多
Intracranial aneurysms are pathological dilatations which endanger people＇s health. Hemodynamics is thought to be an important factor in the pathogenesis and treatment of aneurysms. To date, the bulk of investigation...Intracranial aneurysms are pathological dilatations which endanger people＇s health. Hemodynamics is thought to be an important factor in the pathogenesis and treatment of aneurysms. To date, the bulk of investigations into hemodynamics have been conducted by making use of mathematically idealized models for rigid aneurysms and associated arteries. However the walls of aneurysms and associated arteries are elastic in vivo. This study shows the differences of the simulation between elastic and rigid wall models. The numerical simulation of elastic aneurysm model is made fi＇om a representative Digital Subtraction Angiography （DSA） image and calculated with CFD software to get the wall deformation and the velocity field. Then the results are analyzed. By comparing the simulation results of the two models from their velocity vectors and shear stress distribution, many differences can be noted. The main difference exists in the distribution of velocity magnitude at some sections, with one outlet having obviously off-center distribution for the elastic wall model. The currents of the distribution of wall shear stress along the wall of aneurysm simulated in rigid and elastic wall models were similar. But there were apparent differences between the two models on the values of wall shear stress especially at the neck of aneurysm. The off-center distribution of velocity magnitude affects the distribution of wall shear stress and the exchange of substance through the wall. The analysis demonstrated clearly that the results of 2-D elastic numerical simulation were in good agreement with the clinical and pathological practice. The results of this study play an important role in the formation, growth, rupture and prognosis of an aneurysm on clinic application.展开更多
基金National Key R&D Program of China(2017YFC0212700)National Natural Science Foundation of China(11304157)+1 种基金“Six Talent Peaks”project in Jiangsu Province(2015-JNHB-011)College Students’Practice Innovation Training Program of Nuist(201810300033Z)
基金This project was supported by the Natural Science Foundation of the Higher Education Institutions of Jiangsu Province of China(No.18KJA140002)National Natural Science Foundation of China(Nos.11564040,21763027)+1 种基金Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX18_1015)Undergraduate Training Program for Innovation and Entrepreneurship(Nos.201710762008,201710762055)
文摘Oxalyl chloride is a highly toxic and caustic substance, which widely exists in human production and life as a kind of volatile organic compound. Based on the density functional theory B3 LYP at 6-311++G(d, p) level, the influences of external electric field on the bond length, bond energy, dipole moment and dissociation mechanism are optimized. The results indicate that the C_1–Cl_3 bond length increases while the C_4–Cl_6 bond decreases. At the same time, the carbon-carbon bond length gradually increases with the increase of electric field. The total energy decreases while the dipole moment gradually increases with the increase of electric field. In the infrared spectra, the vibration frequency of the carbon-chlorine(C_4–Cl_6) bond decreases while the vibration frequency of the carbon-oxygen bond increases. In the ultraviolet-visible spectra, the wavelength of the strongest absorption peak increases as the external electric field increases and shows an observable red shift phenomenon. Additionally, single point energies of oxalyl chloride along the carbon-carbon bond are scanned with the equation-of-motion coupled cluster method restricted to single and double excitations(EOM-CCSD) method and the potential energy curves under different external electric fields are obtained. The dissociation barrier in potential energy curve decreases because of the breakage of carbon-carbon bond with the increase of external electric field. These results provide reference for further researches on the properties of oxalyl chloride and offer a theoretical basis for the study of oxalyl chloride degradation.
基金supported by the National Natural Science Foundation of China (Grant No. 30200289)the Natural Science Foundation of Beijing (Grant No. 7022008)+1 种基金the Key Subject Foundation of Shanghai Municipality (T0302)the New Star Plan of Science and Technology of Beijing (Grant No. H020820950130)
文摘Intracranial aneurysms are pathological dilatations which endanger people＇s health. Hemodynamics is thought to be an important factor in the pathogenesis and treatment of aneurysms. To date, the bulk of investigations into hemodynamics have been conducted by making use of mathematically idealized models for rigid aneurysms and associated arteries. However the walls of aneurysms and associated arteries are elastic in vivo. This study shows the differences of the simulation between elastic and rigid wall models. The numerical simulation of elastic aneurysm model is made fi＇om a representative Digital Subtraction Angiography （DSA） image and calculated with CFD software to get the wall deformation and the velocity field. Then the results are analyzed. By comparing the simulation results of the two models from their velocity vectors and shear stress distribution, many differences can be noted. The main difference exists in the distribution of velocity magnitude at some sections, with one outlet having obviously off-center distribution for the elastic wall model. The currents of the distribution of wall shear stress along the wall of aneurysm simulated in rigid and elastic wall models were similar. But there were apparent differences between the two models on the values of wall shear stress especially at the neck of aneurysm. The off-center distribution of velocity magnitude affects the distribution of wall shear stress and the exchange of substance through the wall. The analysis demonstrated clearly that the results of 2-D elastic numerical simulation were in good agreement with the clinical and pathological practice. The results of this study play an important role in the formation, growth, rupture and prognosis of an aneurysm on clinic application.
