A lead-shielded HPGe detector and offlineγ-ray spectra of the residual product were used to measure the cross section(CS)and ratios of isomeric CS(σm/σg)in^(134)Xe(n,2n)^(133m),gXe reactions at different energies(1...A lead-shielded HPGe detector and offlineγ-ray spectra of the residual product were used to measure the cross section(CS)and ratios of isomeric CS(σm/σg)in^(134)Xe(n,2n)^(133m),gXe reactions at different energies(13.5 MeV,13.8 MeV,14.1 MeV,14.4 MeV,14.8 MeV)relative to the^(93)Nb(n,2n)^(92)mNb reaction CS.The target was high-purity natural Xe gas under high pressure.The T(d,n)4He reaction produces neutrons.TALYS code(version 1.95)for nuclear reactions was used for calculations,with default parameters and nuclear level density models.The uncertainties in the measured CS data were thoroughly analyzed using the covariance analysis method.The results were compared with theoretical values,evaluation data,and previous experimental findings.CS data of the 134Xe(n,2n)133mXe and 134Xe(n,2n)133gXe reactions and the corresponding isomeric CS ratios at 13.5 MeV,13.8 MeV,and 14.1 MeV neutron energies are reported for the first time.This research advances our knowledge of pre-equilibrium emission in the(n,2n)reaction channel by resolving inconsistencies in the Xe data.展开更多
Exploring aqueous nano-fabrication with monodisperse and hierarchical characteristics is fundamentally and technically significant.Herein,we discover that inter-particle nano–nano scale interactions profoundly affect...Exploring aqueous nano-fabrication with monodisperse and hierarchical characteristics is fundamentally and technically significant.Herein,we discover that inter-particle nano–nano scale interactions profoundly affect the products’morphology ranging from polydisperse→monodisperse to individual→hierarchical manipulation.Accordingly,we present a“nucleationgrowth-dispersion triple modulation”strategy for fabricating monodisperse Cu2−xE(E=S,Se,Te)nanocrystals(NCs)and supraparticles(SPs).Such full-process and cross-scale control is conducted by two rationally selected ligands(cysteine and citrate molecules),which are responsible for atom/molecule–nano and nano–nano interaction modulations,respectively.Cysteine reacts with the cations and forms low reactive(cysteine-Cu+)n coordination polymers,which overcomes the commonly concerned nucleation and particle growth induced polydispersity.Citrate,by virtue of its strong negative charge modulated NC–NC interactions,decides the products morphology from polydisperse products to monodisperse NCs to monodisperse hierarchical SPs.These findings not only present new insights into aqueous nano-synthesis chemistry but provide an eco-friendly system for versatile and high-quality nano-entity fabrication.展开更多
In this work, we describe a new electrode-less radio-frequency（RF） excitation technique for generating excimers in the vacuum ultraviolet（VUV） and ultraviolet（UV） spectral regions for potential biological/chemic...In this work, we describe a new electrode-less radio-frequency（RF） excitation technique for generating excimers in the vacuum ultraviolet（VUV） and ultraviolet（UV） spectral regions for potential biological/chemical applications. Spectra data of Xe~＊_2, XeI~＊, and KrI~＊ generated by this new technique are presented. Optical efficiency of the lamp system ranges from 3% to 6% for KrI~＊, 7% to 13% for XeI~＊, and 15% to 20% for Xe~＊_2. Also, results of irradiating E-coli with XeI~＊discharge from this lamp system is presented to show one of the promising applications of such electrode-less apparatus.This new RF lamp system offers an interesting addition to the already existing technologies for generating VUV and UV light for various biological, physical, and chemical processes especially those requiring large area for high productivity.展开更多
基金supported by the National Natural science Foundation of China(Nos.11875016,12165006).
文摘A lead-shielded HPGe detector and offlineγ-ray spectra of the residual product were used to measure the cross section(CS)and ratios of isomeric CS(σm/σg)in^(134)Xe(n,2n)^(133m),gXe reactions at different energies(13.5 MeV,13.8 MeV,14.1 MeV,14.4 MeV,14.8 MeV)relative to the^(93)Nb(n,2n)^(92)mNb reaction CS.The target was high-purity natural Xe gas under high pressure.The T(d,n)4He reaction produces neutrons.TALYS code(version 1.95)for nuclear reactions was used for calculations,with default parameters and nuclear level density models.The uncertainties in the measured CS data were thoroughly analyzed using the covariance analysis method.The results were compared with theoretical values,evaluation data,and previous experimental findings.CS data of the 134Xe(n,2n)133mXe and 134Xe(n,2n)133gXe reactions and the corresponding isomeric CS ratios at 13.5 MeV,13.8 MeV,and 14.1 MeV neutron energies are reported for the first time.This research advances our knowledge of pre-equilibrium emission in the(n,2n)reaction channel by resolving inconsistencies in the Xe data.
基金This work was financially supported by the National Natural Science Foundation of China(No.21775004)and Wanjiang Scholar program。
文摘Exploring aqueous nano-fabrication with monodisperse and hierarchical characteristics is fundamentally and technically significant.Herein,we discover that inter-particle nano–nano scale interactions profoundly affect the products’morphology ranging from polydisperse→monodisperse to individual→hierarchical manipulation.Accordingly,we present a“nucleationgrowth-dispersion triple modulation”strategy for fabricating monodisperse Cu2−xE(E=S,Se,Te)nanocrystals(NCs)and supraparticles(SPs).Such full-process and cross-scale control is conducted by two rationally selected ligands(cysteine and citrate molecules),which are responsible for atom/molecule–nano and nano–nano interaction modulations,respectively.Cysteine reacts with the cations and forms low reactive(cysteine-Cu+)n coordination polymers,which overcomes the commonly concerned nucleation and particle growth induced polydispersity.Citrate,by virtue of its strong negative charge modulated NC–NC interactions,decides the products morphology from polydisperse products to monodisperse NCs to monodisperse hierarchical SPs.These findings not only present new insights into aqueous nano-synthesis chemistry but provide an eco-friendly system for versatile and high-quality nano-entity fabrication.
基金the Jeffress Memorial Trust Fund(Grant No.J-756)the Virginia Federation of Independent Colleges(VFIC)
文摘In this work, we describe a new electrode-less radio-frequency（RF） excitation technique for generating excimers in the vacuum ultraviolet（VUV） and ultraviolet（UV） spectral regions for potential biological/chemical applications. Spectra data of Xe~＊_2, XeI~＊, and KrI~＊ generated by this new technique are presented. Optical efficiency of the lamp system ranges from 3% to 6% for KrI~＊, 7% to 13% for XeI~＊, and 15% to 20% for Xe~＊_2. Also, results of irradiating E-coli with XeI~＊discharge from this lamp system is presented to show one of the promising applications of such electrode-less apparatus.This new RF lamp system offers an interesting addition to the already existing technologies for generating VUV and UV light for various biological, physical, and chemical processes especially those requiring large area for high productivity.
