From the perspective of group standards, the dynamics of the cosmetic industry in the past few years were briefly reviewed and analyzed, including the number of group standards published, types of group standards, gro...From the perspective of group standards, the dynamics of the cosmetic industry in the past few years were briefly reviewed and analyzed, including the number of group standards published, types of group standards, groups, and geographical distribution of the groups. The large number of participating groups and the wide range of geographical distribution indicated that group standards could play a positive role in the sustained and positive development of cosmetic industry. The future development of cosmetic industry was also prospected。展开更多
Ammonia (NH<sub>3</sub>) dissociation and oxidation in a cylindrical quartz reactor has been experimentally studied for various inlet NH<sub>3</sub> concentrations (5%, 10%, and 15%) and reacto...Ammonia (NH<sub>3</sub>) dissociation and oxidation in a cylindrical quartz reactor has been experimentally studied for various inlet NH<sub>3</sub> concentrations (5%, 10%, and 15%) and reactor temperatures between 700 K and 1000 K. The thermal effects during both NH<sub>3</sub> dissociation (endothermic) and oxidation (exothermic) were observed using a bundle of thermocouples positioned along the central axis of the quartz reactor, while the corresponding NH<sub>3</sub> conversions and nitrogen oxides emissions were determined by analysing the gas composition of the reactor exit stream. A stronger endothermic effect, as indicated by a greater temperature drop during NH<sub>3</sub> dissociation, was observed as the NH<sub>3</sub> feed concentration and reactor temperature increased. During NH<sub>3</sub> oxidation, a predominantly greater exothermic effect with increasing NH<sub>3</sub> feed concentration and reactor temperature was also evident;however, it was apparent that NH<sub>3</sub> dissociation occurred near the reactor inlet, preceding the downstream NH<sub>3</sub> and H<sub>2</sub> oxidation. For both NH<sub>3</sub> dissociation and oxidation, NH<sub>3</sub> conversion increased with increasing temperature and decreasing initial NH<sub>3</sub> concentration. Significant levels of NO<sub>X</sub> emissions were observed during NH<sub>3</sub> oxidation, which increased with increasing temperature. From the experimental results, it is speculated that the stainless-steel in the thermocouple bundle may have catalysed NH<sub>3</sub> dissociation and thus changed the reaction chemistry during NH<sub>3</sub> oxidation.展开更多
Understanding the interaction of CH4 with kaolinite is significant for researchers in the fields of coalbed CH4 and shale gas.The diffusion behaviors of CH4 in kaolinite with water contents ranging from 0 to 5 wt% hav...Understanding the interaction of CH4 with kaolinite is significant for researchers in the fields of coalbed CH4 and shale gas.The diffusion behaviors of CH4 in kaolinite with water contents ranging from 0 to 5 wt% have been analyzed by molecular dynamics simulations.The results of the simulations indicate that CH4 molecules can jump between adjacent holes in the kaolinite matrix.CH4 diffusion coefficient was very low (3.28 × 10-9 m2/s) and increased linearly with the increasing of water content.As the water content decreased,the value of radial distribution function first peak between CH4 and oxygen was larger,meaning that with lower water content,the interaction energy between CH4 and oxygen in kaolinite is stronger.The interaction between CH4 and water is linearly positively correlated with water content,in contrast,the interaction energy between kaolinite and water as well as between kaolinite and CH4 decreased linearly with increasing water content.On the other hand,the diffusion of CH4 molecules adsorbed on the surfaces also can be accelerated by the fast diffusion of water molecules in the middle micropore of the kaolinite.展开更多
Herein,a novel single-atomic Pt doping and interface-rich CoS/Co(OH)_(2)(Pt-CoS/Co(OH)_(2)/C)electrocatalyst has been successfully prepared.Benefiting from precise regulation of d-orbital electronic structure modulati...Herein,a novel single-atomic Pt doping and interface-rich CoS/Co(OH)_(2)(Pt-CoS/Co(OH)_(2)/C)electrocatalyst has been successfully prepared.Benefiting from precise regulation of d-orbital electronic structure modulation on Co site,Pt-CoS/Co(OH)_(2)/C exhibited remarkable HER activity and high stability for hydrogen evolution in splitting both water(73 mV@10 mA·cm^(−2)) and seawater(87 mV@10 mA·cm^(−2)).Notably,atomic Pt doping was introduced into CoS/Co(OH)_(2),which could produce local unbalanced Coulombic force and significantly increased the number of S vacancies,and then expose abundant Co sites.Meantime,Co(OH)_(2) in Pt-CoS/Co(OH)_(2)/C could act as the adsorption sites for H_(2)O in hydrogen evolution reaction process.Density functional theory results also proved that atomic Pt doping,S vacancies and Co(OH)_(2) coupling could result in the formation of enriched electronic Co sites and optimize d_(z2) orbital electronic structure,and then realize the depth upward shift of d-band center and enhance the adsorption of H*on Co sites.展开更多
We investigate the ground states of spin-1 Bose–Einstein condensates (BECs) with spin–orbit coupling in a radiallyperiodic potential by numerically solving the coupled Gross–Pitaevskii equations. In the radially pe...We investigate the ground states of spin-1 Bose–Einstein condensates (BECs) with spin–orbit coupling in a radiallyperiodic potential by numerically solving the coupled Gross–Pitaevskii equations. In the radially periodic potential, wefirst demonstrate that spin–orbit-coupled antiferromagnetic BECs support a multiring petal phase. Polar–core vortex canbe observed from phase profiles, which is manifested as circularly symmetric distribution. We further show that spin–orbitcoupling can induce multiring soliton structure in ferromagnetic BECs. It is confirmed especially that the wave-functionphase of the ring corresponding to uniform distribution satisfies the rotational symmetry, and the wave-function phase ofthe ring corresponding to partial splitting breaks the rotational symmetry. Adjusting the spin–orbit coupling strength cancontrol the number of petal in antiferromagnetic BECs and the winding numbers of wave-function in ferromagnetic BECs.Finally, we discuss effects of spin-independent and spin-dependent interactions on the ground states.展开更多
There is a close relationship between the Painlevéintegrability and other integrability of nonlinear evolution equation.By using the Weiss-Tabor-Carnevale(WTC)method and the symbolic computation of Maple,the Pain...There is a close relationship between the Painlevéintegrability and other integrability of nonlinear evolution equation.By using the Weiss-Tabor-Carnevale(WTC)method and the symbolic computation of Maple,the Painlevétest is used for the higher order generalized non-autonomous equation and the third order Korteweg-de Vries equation with variable coefficients.Finally the Painlevéintegrability condition of this equation is gotten.展开更多
To address the fast productivity decline of the horizontal wells and low oil recovery during natural depletion in Baikouquan formation,the approach of solution gas re-injection was proposed with the primary objective ...To address the fast productivity decline of the horizontal wells and low oil recovery during natural depletion in Baikouquan formation,the approach of solution gas re-injection was proposed with the primary objective of further developing this formation.Herein,a field-scale numerical compositional reservoir model was built up based on the formation properties and then the effects of permeability,fractures and formation stress on the production dynamics were thoroughly investigated.A sensitivity analysis,which can correlate the oil recovery with these parameters,was also performed.The results showed that the re-injection of solution gas could remarkably retard the production depletion of the horizontal wells thereby improving the oil production.The oil recovery rate increased with permeability,fracture half-length,fracture conductivity,and formation dip.With regard to the fracture distribution,it was found that the interlaced fracture outperformed the aligned fracture for the solution gas re-injection.The influence of the formation stress should be carefully considered in the production process.Sensitivity analysis indicated that the formation dip was the paramount parameter,and the permeability,fracture half-length,and fracture conductivity also played central roles.The results of this study supplement earlier observations and provide constructive envision for enhanced oil recovery of tight reservoirs.展开更多
文摘From the perspective of group standards, the dynamics of the cosmetic industry in the past few years were briefly reviewed and analyzed, including the number of group standards published, types of group standards, groups, and geographical distribution of the groups. The large number of participating groups and the wide range of geographical distribution indicated that group standards could play a positive role in the sustained and positive development of cosmetic industry. The future development of cosmetic industry was also prospected。
文摘Ammonia (NH<sub>3</sub>) dissociation and oxidation in a cylindrical quartz reactor has been experimentally studied for various inlet NH<sub>3</sub> concentrations (5%, 10%, and 15%) and reactor temperatures between 700 K and 1000 K. The thermal effects during both NH<sub>3</sub> dissociation (endothermic) and oxidation (exothermic) were observed using a bundle of thermocouples positioned along the central axis of the quartz reactor, while the corresponding NH<sub>3</sub> conversions and nitrogen oxides emissions were determined by analysing the gas composition of the reactor exit stream. A stronger endothermic effect, as indicated by a greater temperature drop during NH<sub>3</sub> dissociation, was observed as the NH<sub>3</sub> feed concentration and reactor temperature increased. During NH<sub>3</sub> oxidation, a predominantly greater exothermic effect with increasing NH<sub>3</sub> feed concentration and reactor temperature was also evident;however, it was apparent that NH<sub>3</sub> dissociation occurred near the reactor inlet, preceding the downstream NH<sub>3</sub> and H<sub>2</sub> oxidation. For both NH<sub>3</sub> dissociation and oxidation, NH<sub>3</sub> conversion increased with increasing temperature and decreasing initial NH<sub>3</sub> concentration. Significant levels of NO<sub>X</sub> emissions were observed during NH<sub>3</sub> oxidation, which increased with increasing temperature. From the experimental results, it is speculated that the stainless-steel in the thermocouple bundle may have catalysed NH<sub>3</sub> dissociation and thus changed the reaction chemistry during NH<sub>3</sub> oxidation.
基金This research was financially supported by the National Natural Science Foundation of China(Nos.U1810102,51974194)The use of the Materials Studio software package,which is supported by the Key Laboratory of Coal Science and Technology of the Ministry of Education and Shanxi Province,is gratefully acknowledged.
文摘Understanding the interaction of CH4 with kaolinite is significant for researchers in the fields of coalbed CH4 and shale gas.The diffusion behaviors of CH4 in kaolinite with water contents ranging from 0 to 5 wt% have been analyzed by molecular dynamics simulations.The results of the simulations indicate that CH4 molecules can jump between adjacent holes in the kaolinite matrix.CH4 diffusion coefficient was very low (3.28 × 10-9 m2/s) and increased linearly with the increasing of water content.As the water content decreased,the value of radial distribution function first peak between CH4 and oxygen was larger,meaning that with lower water content,the interaction energy between CH4 and oxygen in kaolinite is stronger.The interaction between CH4 and water is linearly positively correlated with water content,in contrast,the interaction energy between kaolinite and water as well as between kaolinite and CH4 decreased linearly with increasing water content.On the other hand,the diffusion of CH4 molecules adsorbed on the surfaces also can be accelerated by the fast diffusion of water molecules in the middle micropore of the kaolinite.
基金This work was financially supported by Shandong Provincial Natural Science Foundation(No.ZR2021QB056)Taishan Scholars Foundation of Shandong province(No.tsqn201909058).
文摘Herein,a novel single-atomic Pt doping and interface-rich CoS/Co(OH)_(2)(Pt-CoS/Co(OH)_(2)/C)electrocatalyst has been successfully prepared.Benefiting from precise regulation of d-orbital electronic structure modulation on Co site,Pt-CoS/Co(OH)_(2)/C exhibited remarkable HER activity and high stability for hydrogen evolution in splitting both water(73 mV@10 mA·cm^(−2)) and seawater(87 mV@10 mA·cm^(−2)).Notably,atomic Pt doping was introduced into CoS/Co(OH)_(2),which could produce local unbalanced Coulombic force and significantly increased the number of S vacancies,and then expose abundant Co sites.Meantime,Co(OH)_(2) in Pt-CoS/Co(OH)_(2)/C could act as the adsorption sites for H_(2)O in hydrogen evolution reaction process.Density functional theory results also proved that atomic Pt doping,S vacancies and Co(OH)_(2) coupling could result in the formation of enriched electronic Co sites and optimize d_(z2) orbital electronic structure,and then realize the depth upward shift of d-band center and enhance the adsorption of H*on Co sites.
基金Project supported by the Scientific and Technologial Innovation Program of the Higher Education Institutions in Shanxi Province,China(Grant Nos.2019L0813,2019L0785,and 2019L0808).
文摘We investigate the ground states of spin-1 Bose–Einstein condensates (BECs) with spin–orbit coupling in a radiallyperiodic potential by numerically solving the coupled Gross–Pitaevskii equations. In the radially periodic potential, wefirst demonstrate that spin–orbit-coupled antiferromagnetic BECs support a multiring petal phase. Polar–core vortex canbe observed from phase profiles, which is manifested as circularly symmetric distribution. We further show that spin–orbitcoupling can induce multiring soliton structure in ferromagnetic BECs. It is confirmed especially that the wave-functionphase of the ring corresponding to uniform distribution satisfies the rotational symmetry, and the wave-function phase ofthe ring corresponding to partial splitting breaks the rotational symmetry. Adjusting the spin–orbit coupling strength cancontrol the number of petal in antiferromagnetic BECs and the winding numbers of wave-function in ferromagnetic BECs.Finally, we discuss effects of spin-independent and spin-dependent interactions on the ground states.
基金Supported by the Shanxi Education Department Project(Grant No.J2020398)Key Natural Science Projects of Shanxi Energy Institute(Grant No.ZZ-2018003)。
文摘There is a close relationship between the Painlevéintegrability and other integrability of nonlinear evolution equation.By using the Weiss-Tabor-Carnevale(WTC)method and the symbolic computation of Maple,the Painlevétest is used for the higher order generalized non-autonomous equation and the third order Korteweg-de Vries equation with variable coefficients.Finally the Painlevéintegrability condition of this equation is gotten.
基金The authors gratefully acknowledge the financial support of the National Natural Science Foundation of China(51974265 and 51804264)Science Foundation Shanxi Province,China(201701D121129)+1 种基金Science Foundation of Shanxi Institute of Energy(ZY-2017001)Youth Science and Technology Innovation Team of SWPU(2017CXTD04).The authors also thank the Computer Modeling Group Ltd.for providing the CMG software for this study.The authors would like to thank the anonymous reviewers for valuable comments and suggestions.
文摘To address the fast productivity decline of the horizontal wells and low oil recovery during natural depletion in Baikouquan formation,the approach of solution gas re-injection was proposed with the primary objective of further developing this formation.Herein,a field-scale numerical compositional reservoir model was built up based on the formation properties and then the effects of permeability,fractures and formation stress on the production dynamics were thoroughly investigated.A sensitivity analysis,which can correlate the oil recovery with these parameters,was also performed.The results showed that the re-injection of solution gas could remarkably retard the production depletion of the horizontal wells thereby improving the oil production.The oil recovery rate increased with permeability,fracture half-length,fracture conductivity,and formation dip.With regard to the fracture distribution,it was found that the interlaced fracture outperformed the aligned fracture for the solution gas re-injection.The influence of the formation stress should be carefully considered in the production process.Sensitivity analysis indicated that the formation dip was the paramount parameter,and the permeability,fracture half-length,and fracture conductivity also played central roles.The results of this study supplement earlier observations and provide constructive envision for enhanced oil recovery of tight reservoirs.
