Stress index of tetrahedron （SIT） was defined to describe the topological connectivities among various sili- con-oxygen tetrahedra （SiOT） in anionic clusters of binary silicate crystals, glasses, and melts. It was...Stress index of tetrahedron （SIT） was defined to describe the topological connectivities among various sili- con-oxygen tetrahedra （SiOT） in anionic clusters of binary silicate crystals, glasses, and melts. It was found that the value of SIT was well correlated with the wavenumber of Raman active symmetric stretching vibration of non-bridging oxygen of SiOT. The spatial fractional dimension of hyperfine structure was introduced while comparative analysis was made with the value of SIT. It can be concluded that the concepts of SIT, vibrational wavenumber, and spatial fractional dimension were inherently and holographically correlated and exhibit isomorphic representations of complex structure of binary silicates. Experimental Raman spectra of binary silicates with different alkali cations were investigated. It was demonstrated that alkali cations have little effect on the vibrational wavenumber of symmetric stretching of non-bridging oxygen （NBO） of SiOT, but remarkably affect its Raman active optical cross section, as was consensus resulted from ab initio calculation. It can also be concluded that the spatial fractional dimension of binary silicate is predominantly determined by the hyperfine structure of the anionic clusters and little affected by alkali cations, although the species of anionic clusters and their distributions were originally assigned by the content of alkali oxides. And Raman optical activity extinct effect of isolated SiOT at high basicity should be considered while being applied to quantitatively analysis.展开更多
Radiotherapy(RT)is one of the important modalities for cancer treatments.Mounting evidence suggests that the host immune system is involved in the tumor cell killing during RT,and future RT technology development shou...Radiotherapy(RT)is one of the important modalities for cancer treatments.Mounting evidence suggests that the host immune system is involved in the tumor cell killing during RT,and future RT technology development should aim to minimize radiation dose to the immune system while maintaining a sufficient dose to the tumor.A brief history of RT technology development is first summarized.Three RT technologies,namely FLASH RT,proton therapy,and spatially fractionated RT(SFRT),are singled out for the era of immunotherapy.Besides the technical aspects,the mechanism of FLASH effect is discussed,which is likely the combined results of the recombination effect,oxygen depletion effect and immune sparing effect.The proton therapy should have the advantage of causing much less immune damage in comparison to X-ray based RT due to the Bragg peak.However,the relative biological effectiveness(RBE)uncertainty and range uncertainty may hinder the translation of this advantage into clinical benefit.Research approaches to overcome these two technical hurdles are discussed.Various SFRT approaches and their application are reviewed.These approaches are categorized as single-field 1D/2D SFRT,multi-field 3D SFRT and quasi-3D SFRT techniques.A 3D SFRT approach,which is achieved by placing the Bragg peak of a proton 2D SFRT field in discrete depths,may have special potential because all 3 technologies(FLASH RT,proton therapy and SFRT)may be used in this approach.展开更多
We investigate a wave equation in the plane with an additive noise which is fractional in time and has a non-degenerate spatial covariance. The equation is shown to admit a process-valued solution. Also we give a cont...We investigate a wave equation in the plane with an additive noise which is fractional in time and has a non-degenerate spatial covariance. The equation is shown to admit a process-valued solution. Also we give a continuity modulus of the solution, and the HSlder continuity is presented.展开更多
基金This work was financially supported by the National Natural Science Foundation of China (Nos. 50334040, 40203001, and 50334050) and Shanghai Research Center for Advanced Materials (No. 98JC14018).
文摘Stress index of tetrahedron （SIT） was defined to describe the topological connectivities among various sili- con-oxygen tetrahedra （SiOT） in anionic clusters of binary silicate crystals, glasses, and melts. It was found that the value of SIT was well correlated with the wavenumber of Raman active symmetric stretching vibration of non-bridging oxygen of SiOT. The spatial fractional dimension of hyperfine structure was introduced while comparative analysis was made with the value of SIT. It can be concluded that the concepts of SIT, vibrational wavenumber, and spatial fractional dimension were inherently and holographically correlated and exhibit isomorphic representations of complex structure of binary silicates. Experimental Raman spectra of binary silicates with different alkali cations were investigated. It was demonstrated that alkali cations have little effect on the vibrational wavenumber of symmetric stretching of non-bridging oxygen （NBO） of SiOT, but remarkably affect its Raman active optical cross section, as was consensus resulted from ab initio calculation. It can also be concluded that the spatial fractional dimension of binary silicate is predominantly determined by the hyperfine structure of the anionic clusters and little affected by alkali cations, although the species of anionic clusters and their distributions were originally assigned by the content of alkali oxides. And Raman optical activity extinct effect of isolated SiOT at high basicity should be considered while being applied to quantitatively analysis.
文摘Radiotherapy(RT)is one of the important modalities for cancer treatments.Mounting evidence suggests that the host immune system is involved in the tumor cell killing during RT,and future RT technology development should aim to minimize radiation dose to the immune system while maintaining a sufficient dose to the tumor.A brief history of RT technology development is first summarized.Three RT technologies,namely FLASH RT,proton therapy,and spatially fractionated RT(SFRT),are singled out for the era of immunotherapy.Besides the technical aspects,the mechanism of FLASH effect is discussed,which is likely the combined results of the recombination effect,oxygen depletion effect and immune sparing effect.The proton therapy should have the advantage of causing much less immune damage in comparison to X-ray based RT due to the Bragg peak.However,the relative biological effectiveness(RBE)uncertainty and range uncertainty may hinder the translation of this advantage into clinical benefit.Research approaches to overcome these two technical hurdles are discussed.Various SFRT approaches and their application are reviewed.These approaches are categorized as single-field 1D/2D SFRT,multi-field 3D SFRT and quasi-3D SFRT techniques.A 3D SFRT approach,which is achieved by placing the Bragg peak of a proton 2D SFRT field in discrete depths,may have special potential because all 3 technologies(FLASH RT,proton therapy and SFRT)may be used in this approach.
基金Supported by NationalNatural Science Foundation of China (Grant No. 10871103)
文摘We investigate a wave equation in the plane with an additive noise which is fractional in time and has a non-degenerate spatial covariance. The equation is shown to admit a process-valued solution. Also we give a continuity modulus of the solution, and the HSlder continuity is presented.
