A new multi-detector array named HALIMA(Hybrid Array for LIfetime MeAsurement)has been developed at Lanzhou for nuclear structure studies in fission.The array comprises eight BGO-shielded High-Purity Germanium detecto...A new multi-detector array named HALIMA(Hybrid Array for LIfetime MeAsurement)has been developed at Lanzhou for nuclear structure studies in fission.The array comprises eight BGO-shielded High-Purity Germanium detectors and twenty fast Ce-doped Lanthanum Bromide[LaBr_(3)(Ce)]detectors shielded with CsI(Tl).HALIMA is further complemented by two ancillary detector systems:fission fragment(FF)detectors and β detectors.This configuration enables precise sub-nanosecond lifetime measurements using the fourfold FF/β-Ge-LaBr_(3)(Ce)-LaBr_(3)(Ce)coincidence technique.The performance and specifications of the detectors,associated electronics,and the data acquisition system are presented in detail.The advantage of FF selectivity is emphasized,which significantly enhances sensitivity to specific fission channels.Using this approach,the lifetimes of the nuclear excited states populated in the spontaneous fission of^(252)Cf were measured,showing good agreement with the established literature values.展开更多
Recent years have witnessed significant improvement in implicit solvents based on the Poisson-Boltzmann theory,whether in the forms of numerical solution or analytical approximation.Especially worth noting are the imp...Recent years have witnessed significant improvement in implicit solvents based on the Poisson-Boltzmann theory,whether in the forms of numerical solution or analytical approximation.Especially worth noting are the improvements and revisions of those implicit solvents for stable dynamics simulations.Given these technical advancements,attentions are now paid to the quality of implicit solvents as compared with the more expensive explicit solvents.The new developments in nonpolar solvents mentioned above and reviewed elsewhere will also result in more accurate simulations of biomolecules.We have also touched the new challenges facing the implicit solvents.That is how to incorporate these solvents in the emerging polarizable force fields.New challenges could also arise from the assumptions underlying all implicit solvents,as recently explored to couple electrostatic and nonelectrostatic components together.In addition,hybrid solvents could eventually become a reality for dynamics simulation even this has been proposed in the early days of computational biochemistry.It is likely that such hybrid solvents will offer the necessary accuracy,as they no longer average out the very degrees of freedom that are of interest in studies where solute/solvent coupling is crucial.展开更多
基金supported by the National Natural Science Foundation of China(Nos.12275321,12121005,12475129,and 12335009)the Natural Science Foundation of Guangdong Province,China(No.2025A1515012112)+5 种基金the International Atomic Energy Agency Coordinated Research Project F41034(No.28649)the computational resources from Sun Yat-sen University the National Supercomputer Center in Guangzhouthe Open Project of Guangxi Key Laboratory of Nuclear Physics and Nuclear Technology(No.NLK2023-08)the Central Government Guidance Funds for Local Scientific and Technological Development,China(No.Guike ZY22096024)the Guangdong Major Project of Basic and Applied Basic Research(No.2021B0301030006)Young Scientists Fund of the National Natural Science Foundation of China(No.12405144)the National Key Research and Development Program(MOST 2022YFA1602304).
文摘A new multi-detector array named HALIMA(Hybrid Array for LIfetime MeAsurement)has been developed at Lanzhou for nuclear structure studies in fission.The array comprises eight BGO-shielded High-Purity Germanium detectors and twenty fast Ce-doped Lanthanum Bromide[LaBr_(3)(Ce)]detectors shielded with CsI(Tl).HALIMA is further complemented by two ancillary detector systems:fission fragment(FF)detectors and β detectors.This configuration enables precise sub-nanosecond lifetime measurements using the fourfold FF/β-Ge-LaBr_(3)(Ce)-LaBr_(3)(Ce)coincidence technique.The performance and specifications of the detectors,associated electronics,and the data acquisition system are presented in detail.The advantage of FF selectivity is emphasized,which significantly enhances sensitivity to specific fission channels.Using this approach,the lifetimes of the nuclear excited states populated in the spontaneous fission of^(252)Cf were measured,showing good agreement with the established literature values.
文摘Recent years have witnessed significant improvement in implicit solvents based on the Poisson-Boltzmann theory,whether in the forms of numerical solution or analytical approximation.Especially worth noting are the improvements and revisions of those implicit solvents for stable dynamics simulations.Given these technical advancements,attentions are now paid to the quality of implicit solvents as compared with the more expensive explicit solvents.The new developments in nonpolar solvents mentioned above and reviewed elsewhere will also result in more accurate simulations of biomolecules.We have also touched the new challenges facing the implicit solvents.That is how to incorporate these solvents in the emerging polarizable force fields.New challenges could also arise from the assumptions underlying all implicit solvents,as recently explored to couple electrostatic and nonelectrostatic components together.In addition,hybrid solvents could eventually become a reality for dynamics simulation even this has been proposed in the early days of computational biochemistry.It is likely that such hybrid solvents will offer the necessary accuracy,as they no longer average out the very degrees of freedom that are of interest in studies where solute/solvent coupling is crucial.
