Hybrid-angle energy-dispersive high-power X-ray diffraction(XRD)with white X-ray beam and a cadmium telluride(CdTe)detector is demonstrated in this work on a CeO_(2) powder sample in a glass vial.In order to select an...Hybrid-angle energy-dispersive high-power X-ray diffraction(XRD)with white X-ray beam and a cadmium telluride(CdTe)detector is demonstrated in this work on a CeO_(2) powder sample in a glass vial.In order to select an appropriate X-ray radiation source that can penetrate the vial and generate diffraction signals of sufficient intensity,an energy spectrum simulation of metals with atomic numbers ranging from 24 to 92 was performed using the Geant4 simulator.On the basis of the aforementioned simulation,a hybrid-angle energy-dispersive X-ray diffraction and fluorescence apparatus was constructed,employing a tungsten target X-ray source and a cadmium telluride detector.Diffraction signals of CeO_(2) powder were obtained in a glass vial with a 0.5 mm wall thickness.Additional research indicates that the XRD patterns also exhibited fluorescence peaks.The fluorescence analysis supplements the diffraction analysis,offering supplementary insights and providing an additional layer of understanding of the elemental composition and distribution within the sample.The full width at half maximum(FWHM)of the peaks in q-space is found to be dependent on the energy resolution of the detector and the angle resolution of the goniometer.It is possible for multi-angle scanning energy-dispersive X-ray diffraction to achieve the same or even smaller FWHM as 2D-XRD if the experimental parameters are properly chosen.展开更多
The hybridization between the localized 4f level(f) with conduction(c) electrons in γ-Ce upon cooling has been previously revealed in single crystalline thin films experimentally and theoretically, whereas its influe...The hybridization between the localized 4f level(f) with conduction(c) electrons in γ-Ce upon cooling has been previously revealed in single crystalline thin films experimentally and theoretically, whereas its influence on the γ → α phase transition was not explicitly verified, due to the fact that the phase transition happened in the bulk-layer, leaving the surface in the γ phase. Here in our work, we circumvent this issue by investigating the effect of alloying addition of La on Ce, by means of crystal structure, electronic transport and angle resolved photoemission spectroscopy measurements, together with a phenomenological periodic Anderson model and a modified Anderson impurity model. Our current researches indicate that the weakening of f–c hybridization is the major factor in the suppression of γ → α phase transition by La doping. The consistency of our results with the effects of other rare earth and actinide alloying additions on the γ → α phase transition of Ce is also discussed. Our work demonstrates the importance of the interaction between f and c electrons in understanding the unconventional phase transition in Ce, which is intuitive for further researches on other rare earth and actinide metals and alloys with similar phase transition behaviors.展开更多
Rose root rot disease caused by Pythium helicoides Drechsler has brought heavy damage to cut rose production in Japan,and it has became apparent that Rosa multiflora showed resistance to this disease.Roses have been b...Rose root rot disease caused by Pythium helicoides Drechsler has brought heavy damage to cut rose production in Japan,and it has became apparent that Rosa multiflora showed resistance to this disease.Roses have been bred by interspecies crossing with Rosa species including of R.multiflora,and many progenies of R.multiflora have been bred as determined cluster-flowered roses.However,the genetic architecture of this resistance remains.So,in this study,four kinds of R.multiflora and 21 rose cultivars that have been clarified in the cross-fertilization genealogy with R.multiflora were used as plant materials,and the inheritability of resistance to root rot disease was investigated.Four kinds of R.multiflora had all high resistance,and the resistance to root rot disease in R.multiflora was inherent characteristic of species.Five varieties not less than 50% in relatedness with R.multiflora were shown as varied ‘resistant’ and ‘moderately resistant’.Therefore,the inherent resistant characteristic in R.multiflora was not controlled by single major gene,and the resistibility in R.multiflora was not cytoplasmic but nuclear heredity.Although there was significant negative relation between relative root rot severity and relatedness with R.multiflora,the variance of relative root rot severity had tendency to expand as relatedness with R.multiflora reduced.This result,therefore,indicated that the contingency of resistance expression increased as the relatedness with R.multiflora was reduced.The varieties having low degree of relatedness with R.multiflora had similar relative root rot severity with R.multiflora.These results indicated that we would be able to select resistant roses from progenies crossed with R.multiflora.展开更多
基金Science and Technology on Surface Physics and Chemistry Laboratory.Grant number(WDZC202205)。
文摘Hybrid-angle energy-dispersive high-power X-ray diffraction(XRD)with white X-ray beam and a cadmium telluride(CdTe)detector is demonstrated in this work on a CeO_(2) powder sample in a glass vial.In order to select an appropriate X-ray radiation source that can penetrate the vial and generate diffraction signals of sufficient intensity,an energy spectrum simulation of metals with atomic numbers ranging from 24 to 92 was performed using the Geant4 simulator.On the basis of the aforementioned simulation,a hybrid-angle energy-dispersive X-ray diffraction and fluorescence apparatus was constructed,employing a tungsten target X-ray source and a cadmium telluride detector.Diffraction signals of CeO_(2) powder were obtained in a glass vial with a 0.5 mm wall thickness.Additional research indicates that the XRD patterns also exhibited fluorescence peaks.The fluorescence analysis supplements the diffraction analysis,offering supplementary insights and providing an additional layer of understanding of the elemental composition and distribution within the sample.The full width at half maximum(FWHM)of the peaks in q-space is found to be dependent on the energy resolution of the detector and the angle resolution of the goniometer.It is possible for multi-angle scanning energy-dispersive X-ray diffraction to achieve the same or even smaller FWHM as 2D-XRD if the experimental parameters are properly chosen.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2021YFA1601100 and 2017YFA0303104)the SPC-Lab Research Fund(Grant No.WDZC201901)+3 种基金the Science Challenge Project(Grant Nos.TZ2016004 and TZ2018002)the National Natural Science Foundation of China(Grant Nos.U1630248,11774320,and 11904334)Special Funds of Institute of Materials(Grant No.TP02201904)the Development Funds(Grant No.JZX7Y201901SY00900107)。
文摘The hybridization between the localized 4f level(f) with conduction(c) electrons in γ-Ce upon cooling has been previously revealed in single crystalline thin films experimentally and theoretically, whereas its influence on the γ → α phase transition was not explicitly verified, due to the fact that the phase transition happened in the bulk-layer, leaving the surface in the γ phase. Here in our work, we circumvent this issue by investigating the effect of alloying addition of La on Ce, by means of crystal structure, electronic transport and angle resolved photoemission spectroscopy measurements, together with a phenomenological periodic Anderson model and a modified Anderson impurity model. Our current researches indicate that the weakening of f–c hybridization is the major factor in the suppression of γ → α phase transition by La doping. The consistency of our results with the effects of other rare earth and actinide alloying additions on the γ → α phase transition of Ce is also discussed. Our work demonstrates the importance of the interaction between f and c electrons in understanding the unconventional phase transition in Ce, which is intuitive for further researches on other rare earth and actinide metals and alloys with similar phase transition behaviors.
基金Supported by the Doctoral Scientific Research Foundation of Liaoning Province
文摘Rose root rot disease caused by Pythium helicoides Drechsler has brought heavy damage to cut rose production in Japan,and it has became apparent that Rosa multiflora showed resistance to this disease.Roses have been bred by interspecies crossing with Rosa species including of R.multiflora,and many progenies of R.multiflora have been bred as determined cluster-flowered roses.However,the genetic architecture of this resistance remains.So,in this study,four kinds of R.multiflora and 21 rose cultivars that have been clarified in the cross-fertilization genealogy with R.multiflora were used as plant materials,and the inheritability of resistance to root rot disease was investigated.Four kinds of R.multiflora had all high resistance,and the resistance to root rot disease in R.multiflora was inherent characteristic of species.Five varieties not less than 50% in relatedness with R.multiflora were shown as varied ‘resistant’ and ‘moderately resistant’.Therefore,the inherent resistant characteristic in R.multiflora was not controlled by single major gene,and the resistibility in R.multiflora was not cytoplasmic but nuclear heredity.Although there was significant negative relation between relative root rot severity and relatedness with R.multiflora,the variance of relative root rot severity had tendency to expand as relatedness with R.multiflora reduced.This result,therefore,indicated that the contingency of resistance expression increased as the relatedness with R.multiflora was reduced.The varieties having low degree of relatedness with R.multiflora had similar relative root rot severity with R.multiflora.These results indicated that we would be able to select resistant roses from progenies crossed with R.multiflora.
