Laser-induced electron diffraction（LIED）, in which elastic scattering of the returning electron with the parent ion takes place, has been used to extract atomic potential and image molecular structures with sub-？A ...Laser-induced electron diffraction（LIED）, in which elastic scattering of the returning electron with the parent ion takes place, has been used to extract atomic potential and image molecular structures with sub-？A precision and exposure time of a few femtoseconds. So far, the polarization and exchange effects have not been taken into account in the theoretical calculation of differential cross section（DCS） for the laser-induced rescattering processes. However, the validity of this theoretical treatment has never been verified. In this work, we investigate the polarization and exchange effects on electron impact elastic scattering with rare gas atoms and ions. It is found that, while the exchange effect generally plays a more important role than the polarization effect in the elastic scattering process, the exchange effect is less important on electron–ion collisions than on electron–atom collisions, especially for scattering in backward direction. In addition, our calculations show that, for electron–atom collisions at incident energies above 50 e V, both the polarization and exchange effects can be safely neglected, while for electron–ion collisions, both the polarization and exchange potentials do not make substantial contributions to the DCS at incident energies above 20 e V and scattering angles larger than 90？. Our investigation confirms the validity of the current LIED method.展开更多
In this paper by means of generalized shooting method and homotopy technique a numerical method was given for computing free multipoint boundary value problem proposed in the intervention of exchange rate by Cadenilla...In this paper by means of generalized shooting method and homotopy technique a numerical method was given for computing free multipoint boundary value problem proposed in the intervention of exchange rate by Cadenillas and Femaado Zapatero. A numerical example was given for illustrating the validity of this method.展开更多
The technique of modeling operating temperature variations of shell-and-tube heat exchanger 10-E-01 of kerosene-crude oil streams of Port Harcourt refinery crude distillation unit is presented in this research. A...The technique of modeling operating temperature variations of shell-and-tube heat exchanger 10-E-01 of kerosene-crude oil streams of Port Harcourt refinery crude distillation unit is presented in this research. Appropriate first-order model equations were developed applying principles of energy balance. The differential equations developed for the process streams which exchanged heat was evaluated numerically to predict the temperature variations as a function of time. The relevant parameters associated with typical heat exchanger works were calculated using plant data of 10-E-02. The model strives to predict the final kerosene temperature from 488 to 353.6 K. While the crude oil streams temperature rose from 313 to 353.6 K. The developed model enables the operator to predict the final temperature at the kerosene hydro-treating unit and thereby prevent regular emergency shutdowns due to excessive temperature rise.展开更多
A study of single-electron capture(SEC) in 18-240 keV O^(6+)-Ne collisions has been conducted employing a combination of experimental and theoretical methodologies.Utilizing a reaction microscope,state-selective SEC c...A study of single-electron capture(SEC) in 18-240 keV O^(6+)-Ne collisions has been conducted employing a combination of experimental and theoretical methodologies.Utilizing a reaction microscope,state-selective SEC cross sections and projectile scattering angle distributions were obtained.The translational energy spectra for SEC reveal the prevailing capture into n=3 states of the projectile ion,with a minor contribution from n=4 states.Notably,as the projectile's energy increases,the relative contribution of SEC n=4 states increases while that of SEC n=3 states diminishes.Furthermore,we computed state-selective relative cross sections and angular differential cross sections employing the classical molecular Coulomb over-the-barrier model(MCBM) and the multichannel Landau-Zener(MCLZ) model.A discernible discrepancy between the state-selective cross sections from the two theoretical models is apparent for the considered impact energies.However,regarding the angular differential cross sections,an overall agreement was attained between the current experimental results and the theoretical results from the MCLZ model.展开更多
An in vitro cultured rat perirenal preadipocyte (PA) was established as a model system to investigate the role of the intracellular pH (pHi) and of the Na+/H+ exchanger during PA proliferation and differentiation. pH ...An in vitro cultured rat perirenal preadipocyte (PA) was established as a model system to investigate the role of the intracellular pH (pHi) and of the Na+/H+ exchanger during PA proliferation and differentiation. pH sensitive probe, 2' ,7'-bis-(2-carboxyethyl)-5(6)-carboxyfluorescein(BCECF) , was employed to measure the pHi of PA and to determine the Na+/H+ exchange activity. The results showed that there was Na+/H+ exchange activity in the plasma membrane of PA, FCS stimulated DNA synthesis measured by H-TdR incorporation, and the activation of Na + /H + exchanger resulted in pHi increase (nearly 0.2 pH unit) within 2 min. Ethyl-isopropyl-amiloride (EIPA) , a specific Na+/H+ exchange inhibitor, inhibited Na+/H+ exchange activity and DNA synthesis. In the absence of serum insulin did not stimulate DNA synthesis but did induce PA differentiation characterized by the appearance of adiposome in the cell and the enhancement of glycerol-3-phosphate dehydrogenase (G3 PDHase) activity. Meantime, insulin was also found to stimulate Na+/H+ exchange activity and pHi increase. EIPA inhibited Na+/H+ exchanger activation induced by insulin and also partially inhibited the enhancement of G3PDHase activity. These results demonstrated that the activation of Na+ /H+ exchange and the resulting pHi increase are the early events related to both proliferation and differentiation of PA.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11274219)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry,China
文摘Laser-induced electron diffraction（LIED）, in which elastic scattering of the returning electron with the parent ion takes place, has been used to extract atomic potential and image molecular structures with sub-？A precision and exposure time of a few femtoseconds. So far, the polarization and exchange effects have not been taken into account in the theoretical calculation of differential cross section（DCS） for the laser-induced rescattering processes. However, the validity of this theoretical treatment has never been verified. In this work, we investigate the polarization and exchange effects on electron impact elastic scattering with rare gas atoms and ions. It is found that, while the exchange effect generally plays a more important role than the polarization effect in the elastic scattering process, the exchange effect is less important on electron–ion collisions than on electron–atom collisions, especially for scattering in backward direction. In addition, our calculations show that, for electron–atom collisions at incident energies above 50 e V, both the polarization and exchange effects can be safely neglected, while for electron–ion collisions, both the polarization and exchange potentials do not make substantial contributions to the DCS at incident energies above 20 e V and scattering angles larger than 90？. Our investigation confirms the validity of the current LIED method.
文摘In this paper by means of generalized shooting method and homotopy technique a numerical method was given for computing free multipoint boundary value problem proposed in the intervention of exchange rate by Cadenillas and Femaado Zapatero. A numerical example was given for illustrating the validity of this method.
文摘The technique of modeling operating temperature variations of shell-and-tube heat exchanger 10-E-01 of kerosene-crude oil streams of Port Harcourt refinery crude distillation unit is presented in this research. Appropriate first-order model equations were developed applying principles of energy balance. The differential equations developed for the process streams which exchanged heat was evaluated numerically to predict the temperature variations as a function of time. The relevant parameters associated with typical heat exchanger works were calculated using plant data of 10-E-02. The model strives to predict the final kerosene temperature from 488 to 353.6 K. While the crude oil streams temperature rose from 313 to 353.6 K. The developed model enables the operator to predict the final temperature at the kerosene hydro-treating unit and thereby prevent regular emergency shutdowns due to excessive temperature rise.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11934004,12064040,and 11974358)the National Key Research and Development Program of China(Grant No.2022YFA1602500)Strategic Key Research Program of the Chinese Academy of Sciences(Grant No.XDB34020000)。
文摘A study of single-electron capture(SEC) in 18-240 keV O^(6+)-Ne collisions has been conducted employing a combination of experimental and theoretical methodologies.Utilizing a reaction microscope,state-selective SEC cross sections and projectile scattering angle distributions were obtained.The translational energy spectra for SEC reveal the prevailing capture into n=3 states of the projectile ion,with a minor contribution from n=4 states.Notably,as the projectile's energy increases,the relative contribution of SEC n=4 states increases while that of SEC n=3 states diminishes.Furthermore,we computed state-selective relative cross sections and angular differential cross sections employing the classical molecular Coulomb over-the-barrier model(MCBM) and the multichannel Landau-Zener(MCLZ) model.A discernible discrepancy between the state-selective cross sections from the two theoretical models is apparent for the considered impact energies.However,regarding the angular differential cross sections,an overall agreement was attained between the current experimental results and the theoretical results from the MCLZ model.
基金Project supported partially by the Foundation of State Key Laboratory of BiomembraneMembrane Biotechnology, Institute of Zoology, the Chinese Academy of Sciences and the Foundation of Institute of Zoology, the Chinese Academy of Sciences.
文摘An in vitro cultured rat perirenal preadipocyte (PA) was established as a model system to investigate the role of the intracellular pH (pHi) and of the Na+/H+ exchanger during PA proliferation and differentiation. pH sensitive probe, 2' ,7'-bis-(2-carboxyethyl)-5(6)-carboxyfluorescein(BCECF) , was employed to measure the pHi of PA and to determine the Na+/H+ exchange activity. The results showed that there was Na+/H+ exchange activity in the plasma membrane of PA, FCS stimulated DNA synthesis measured by H-TdR incorporation, and the activation of Na + /H + exchanger resulted in pHi increase (nearly 0.2 pH unit) within 2 min. Ethyl-isopropyl-amiloride (EIPA) , a specific Na+/H+ exchange inhibitor, inhibited Na+/H+ exchange activity and DNA synthesis. In the absence of serum insulin did not stimulate DNA synthesis but did induce PA differentiation characterized by the appearance of adiposome in the cell and the enhancement of glycerol-3-phosphate dehydrogenase (G3 PDHase) activity. Meantime, insulin was also found to stimulate Na+/H+ exchange activity and pHi increase. EIPA inhibited Na+/H+ exchanger activation induced by insulin and also partially inhibited the enhancement of G3PDHase activity. These results demonstrated that the activation of Na+ /H+ exchange and the resulting pHi increase are the early events related to both proliferation and differentiation of PA.
