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1.
结出了双重Q^2重标度模型的重标度参数经验公式,其中建立了重标度参数ξV,ξS及ξG与原子核平均结合能之间的联系,利用这套公式可以给出A≥12的所有核的重标度参数值,进而可以采用这些重标度参数值计算有关核过程做出预言。  相似文献   

2.
给出了双重Q2 重标度模型的重标度参数经验公式 ,其中建立了重标度参数 ξV,ξS 及 ξG 与原子核平均结合能之间的联系 .利用这套公式可以给出A≥ 1 2的所有核的重标度参数值 ,进而可以采用这些重标度参数值计算有关核过程做出预言 .  相似文献   

3.
给出了双重Q2重标度模型的重标度参数经验公式,其中建立了重标度参数ξVS及ξG与原子核平均结合能之间的联系.利用这套公式可以给出A≥12的所有核的重标度参数值,进而可以采用这些重标度参数值计算有关核过程做出预言.  相似文献   

4.
与原子核的平均结合能相联系,给出了部分子的推广x重新标度模型的重标度参数公式.利用该公式给出的重标度参数值,计算了铝核、钙核、铅核分别与碳核DIS过程的平均结构函数之比,结果表明理论计算与实验数据符合较好.  相似文献   

5.
提出了改进的双重Q2重标度模型,在保持核动量守恒的条件下,用唯象的方法找到了一套重标度参数公式,建立了重标度参数ξv,ξs及ξg与原子核平均结合能之间的联系.利用该模型所得到的束缚核子内部分子分布函数,对核DIS过程,核Drell-Yan过程和J/Ψ光生过程均给出满意的解释.  相似文献   

6.
高永华  何祯民  段春贵 《物理学报》2001,50(6):1028-1034
提出了改进的双重Q2重标度模型,在保持核动量守恒的条件下,用唯象的方法找到了一套重标度参数公式,建立了重标度参数ξvs及ξg与原子核平均结合能之间的联系.利用该模型所得到的束缚核子内部分子分布函数,对核DIS过程,核Drell-Yan过程和J/Ψ光生过程均给出满意的解释 关键词: 2重标度模型')" href="#">双重Q2重标度模型 核效应 结合能  相似文献   

7.
罗正明  李泰华 《物理学报》1994,43(1):118-123
最近发现,轻离子输运行为具有显著的标度特性,可用一个称为标度输运截面的参数来标定。本文利用这个重要的性质,给出了以标度输运截面为自变量的轻离子粒子数反射系数和能量反射系数的普适拟合公式。此公式具有非常好的单值对应关系,相比之下,经常应用的约化能ε作为标度参数的反射公式,因其分散度大而相形见绌。 关键词:  相似文献   

8.
侯氢  罗正明 《物理学报》1995,44(3):471-478
利用低能轻离子在固体中的输运量可近似由离子标度输运截面单值描述这一标度特性,取得了计算低能轻离子在重靶中射程分布的普适公式,具体地,在用离子输运双群模型计算得到射程分布前四阶矩后,建立这些与标度输运截面之间的近似单值对应关系,在此基础上,拟合得到计算射程分布的前四阶矩以及射程分布的公式.通过与实验值和MonteCarlo计算结果的比较,检验了本文给出的普适公式.利用本文的结果可以较好描述低能轻离子在固体中的射程分布,同时又有很高的计算效率. 关键词:  相似文献   

9.
在AHP应用中提出了各种各样的标度,在分析比较各种标度后,得出指数标度是核心标度的结论,证明了1-9标度与指数标度不相容,指出许多标度实质上只是指数标度的特例,提出了确定指数标度参数的方法,并指出了应用指数标度时应注意的问题及其解决办法。  相似文献   

10.
通过同位旋相关的量子分子动力学模型和统计级联衰变模型, 计算了两个相似的同位旋不同的反应系统的同位旋标度规律, 计算的结果表明对于轻粒子碎片, 同位旋标度系数α随反应时间的增加有所变大, 而对于重的余核产物, α随反应时间的增加有所减小; 轻粒子碎片的α基本上保持不变化, 中等质量和重的余核, α与产物的大小相关, 产物越重α越大. 统计级联衰变可以稍微增加同位旋标度参数α, 但是不改变α对于轻粒子和重产物的变化规律.  相似文献   

11.
A relevant problem regarding entanglement measures is the following: Given an arbitrary mixed state, how does a measure for multipartite entanglement change if general local operations are applied to the state? This question is nontrivial as the normalization of the states has to be taken into account. Here we answer it for pure-state entanglement measures which are invariant under determinant-one local operations and homogeneous in the state coefficients, and their convex-roof extension which quantifies mixed-state entanglement. Our analysis allows us to enlarge the set of mixed states for which these important measures can be calculated exactly. In particular, our results hint at a distinguished role of entanglement measures which have homogeneous degree 2 in the state coefficients.  相似文献   

12.
王宁 《中国物理快报》2004,21(12):2327-2329
We present a new symmetry flow of the Kadomtsev-Petviashvili (KP) hierarchy, which origins from the rescaling of whole “multi-time“ valuables. This flow describes the deformation of solutions of the KP hierarchy with respect to a noncommutative parameter. It is shown that the introduced rescaling symmetry flow does not commute with the ordinary evolution flows of the KP hierarchy, but commutes with the evolution flows with respect to slow-variables.  相似文献   

13.
Laser-induced autofluorescences show a strong intensity distortion for endogenous NADH in the UV and synthesized markers in the NIR range because of tissue optics. Rescaling taking into account bio-optical methods results in the chromophore profile in the observed tissue region. For the in vivo tests an experimental NIR imager was used. NIR fluorescence of the entire body of small animals can be imaged. For first experiments an undifferentiated superficial tumor of mouse thigh was used. Corrections that are due to tissue optics must take care of a more strongly scattering of the light in the NIR range in comparison to the UV fluorescence such as in optical biopsy. For example, the diameter of the fluorescent volume is apparently larger for the same reason. Therefore, the established rescaling from the UV adapted to the NIR range is important for the interpretation fluorescence pictures in biomedicine.  相似文献   

14.
A rescaling procedure is proposed for electron spin echo envelope modulation spectra observed at several electron paramagnetic resonance transitions. Analytical expressions describing the relations between the rescaled frequencies and hyperfine and quadrupole parameters of the remote nucleus are obtained. The dependences of the rescaled data on the external magnetic field and spin projections of the ion nucleus and the remote nuclei are used to derive the parameters of the nuclear state in the crystals Y2SiO5 and YVO4 doped by ion Nd3+.  相似文献   

15.
《Physics letters. A》1998,244(4):237-244
The numerical treatment of anomalous diffusion shows that in some cases Hurst's analysis and the second moment technique express the long-range properties by means of distinctly different rescaling coefficients. With theoretical arguments we show this effect to be determined by the finite speed of the propagation front.  相似文献   

16.
LaAg x In1−x     
The phonon dispersion of LaAg x In1–x (x=1, 0.89, 0.8) has been studied by inelastic neutron scattering in the cubic high temperature phase. A soft mode behaviour was observed at theM-point. The doubling and the cubic to tetragonal deformation of the elementary cell was observed through the phase transition. The measurements of the elastic constants were extended to 450 K and their magnetic field dependence was investigated.This work was supported by the BMFT and the Sonderforschungsbereich 65 Darmstadt/Frankfurt  相似文献   

17.
Mössbauer spectroscopy, X-ray photoemission spectroscopy and magnetization studies of EuCu2?x Fe x Si2, EuCu2Si2?x Ge x , EuCu2?x Si2+x , and EuNi2?x Si2+x have been performed. In EuFe2Si2 and EuNi2Si2 the Eu ion is trivalent, in EuCu2Si2 it is of intermediate valency. In all systems withx=0, many inequivalent Eu sites of intermediate valency are formed. In EuCu2?x Fe x Si2, the average valency of Eu moves nonmonotonically toward Eu3+. In EuCu2Si2?x Ge x , EuCu2?x Si2+x and EuNi2?x Si2+x , the Eu average valency moves quickly towards Eu2+. In all three systems, whenx=1, all Eu ions are already stable divalent. The systems EuCuSi3 and EuNiSi3 order magnetically at 40 K and 34 K, and exhibit hyperfine fields of 323 kOe and 458 kOe, respectively. XPS and Mössbauer isomer shift determinations of the average Eu valence as a function of temperature in EuCu1.5Fe0.5Si2 are in good agreement. The experimental observations concerning the Eu valencies can not be explained solely in terms of the local volume available to the Eu ion; the nature of chemical environment plays a dominant role.  相似文献   

18.
利用x|x|控制混沌系统   总被引:22,自引:0,他引:22       下载免费PDF全文
闵富红  徐振源  须文波 《物理学报》2003,52(6):1360-1364
提出了一种新的混沌控制方法,即对混沌动力系统增加一个具有分段二次函数x|x|形式的非线性反馈控制器,利用它控制了一大类系统从混沌运动转化为各种规则的运动.该控制器是一种活动控制器,它不影响原系统的参数,其结构相当简单而且在物理、电路上都容易实现.数值仿真表明了该控制方法的有效性与可行性. 关键词: 混沌 非线性反馈控制器 分段二次函数  相似文献   

19.
Magnetization and119Sn Mössbauer spectroscopy studies were performed on two pseudoternary systems, namely U x Th1?x CoSn and UCoAl1?x Sn x . Magnetic hyperfine fields on119Sn nuclei were found to be due to local surrounding of U atoms which carry magnetic moments. In pure UCoSn the valuesB hf=8.66 T and μ satisfy the relationB hf=6.75 μB found for a number of UTX compounds studied. Local surrounding effects are indicated by multicomponent spectra obtained for the two pseudoternary series.  相似文献   

20.
The phase composition of the mixed oxides, series LiMe x V2–x O4, where Me=Zn, Mg, was studied using X-ray analysis. The minor phases present in the investigated samples together with the basic spinel phase were determined as Li3VO4 and Zn2V2O7 or Mg2V2O7 respectively. Their presence is caused by the tendency of tetravalent vanadium ions to the disproportionation. For the compositionsx=0·375 were determined the quantitative phase compositions. The lattice constant of the spinel phase is linearly changing according to Vegard's rule, for the zinc series in the range 0x0·375 and for the magnesium series in the range 0xs0·25. Further substitution in magnesium series caused tetragonal deformation of the cubic spinel lattice.The author is indebted to Dr. A.Bergstein for helpful discussions and to Mrs. E.Hrubá for technical assistance.  相似文献   

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