用Coulomb爆炸实测4HeD＋的键长

用1.468 0 MeV ⁴HeD^＋在超薄无衬碳膜中的Coulomb爆炸,获得⁴HeD^＋的键长实测值为(0.097±0.003)nm.讨论了⁴HeD^＋的形成机理.介绍了⁴HeD^＋原始束中D₃＋污染的降低,及产物⁴HeD^＋＋和D^＋高分辨能谱测量中的粒子鉴别方法等.     

低能电子与NⅣ共振散射的R矩阵计算

本文用R矩阵方法精确地计算了N IV的2s²¹S^e,2s2p³P^o和2p²³P^e,¹D^e,¹S^e靶态间的低能电子碰撞激发的碰撞强度和速率系数,并将这些结果与其他理论和实验结果进行了比较。     

89Ru的β缓发质子衰变性质

藉助氦喷嘴带传输系统,采用“p-γ”符合的鉴别原理,成功地合成与鉴别了⁵⁸Ni(³⁶Ar, 2p3n)反应产生的核素⁸⁹Ru,并研究了它的β缓发质子衰变性质.实验给出⁸⁹Ru的衰变半衰期为(1.2±0.2)s, 测定了它的β缓发质子能谱,提取出了⁸⁹Ru经缓发质子衰变布居到子核⁸⁸Mo的2⁺和4⁺态的相对终态分支比(100∶6).通过与统计模型计算结果进行对比,初步指定了⁸⁹Ru基态的自旋 宇称(5/2⁺或7/2^±)和质量过剩(-59.5 MeV).     

20Na衰变性质研究和16O反冲

通过²⁰Ne(p,n)²⁰Na反应,对核天体物理反应中引人注意的²⁰Na衰变作了较深入的研究。发现了²⁰Na的1个新的β⁺延迟a衰变道,其a能量和相对强度分别为(5896±6)keV和(0.0024±0.0003)kev(以2150 kev a峰强度为100)。同时在实验上观察到了²⁰Na β⁺延迟¹⁶O反冲,并由此推断出了β⁺延迟低能a衰变,a平均能量约为780kev,相对强度约为1.4。另外,还就此¹⁶O反冲和低能a衰变,讨论了低能带电粒子在物质中的能量损失规律。最后还对如何进一步甄别²⁰Na β⁺延迟低能a衰变提出了新的探测方法。     

函数空间以及一类奇异积分算子在Hr(Rn)(p＜r≤1)中有界性的准则

在经典H^p(Rⁿ)空间原子分解理论基础上,给出了一种H^p(Rⁿ)空间的新的更为精细的刻划,籍此,给出了一类异奇积分算子在所有H^r(Rⁿ)(p＜r≤1)中有界性的准则     

Hardy-Orlicz-Lorentz空间*

论文利用极大刻画方法介绍了带一般参数的Hardy空间.作为特殊情况, 它们包含了经典H^p空间, Hardy-Lorentz 空间H^p,^q和广义的Hardy-Lorentz空间H^p(φ).     

稀土区质子滴线附近新的β缓发质子衰变

用重离子束³⁵Ar轰击缺中子同位素靶⁹²Mo,⁹⁶Ru和¹⁰⁶Cd产生了质子滴线附近的β缓发质子先驱核¹²⁵Nd,¹²⁸Pm,¹²⁹Sm,¹³⁷Gd和¹³⁹Dy.配合氦喷嘴带传输系统用“p-γ”符合方法对它们进行了肯定的鉴别.它们的半衰期分别为：0.60(15)s,1.0(3)s,0.55(10)s,2.2(2)s和0.6(2)s.用统计模型理论计算对实验测定的¹²⁵Nd, ¹²⁹Sm,¹³⁷Gd和¹³⁹Dy的,和从前报道的¹²¹Ce,¹³⁵Gd的β缓发质子衰变的能谱和分支比进行了拟合.提取出¹²¹Ce, ¹²⁵Nd, ¹²⁹Sm,¹³⁵Gd, ¹³⁷Gd和¹³⁹Dy的基态自旋-宇称分别为5/2^±,5/2^±,1/2⁺(或3/2⁺),5/2⁺,7/2^±和7/2⁺.实验初步指认的基态自旋 宇称值与Nilsson能级图的预言值相符间接表明这6种核素的基态具有大形变,形变参数β₂在0.3左右.     

关于实Hardy空间上的乘子

设H^p(Rⁿ)(00一致有界的乘子族,那么m为H^p(Tⁿ)乘子。并且由此得到了H^p(Tⁿ)乘子在低维空间上的限制性定理。     

一类多线性齐性算子的Hardy空间估计 *

证明了一类带齐性核的奇异积分算子的多线性算子是乘积空间L^p1×L^p2 ×…×L^pK(Rⁿ)到Hardy空间H^r(Rⁿ)和弱Hardy空间H^{r ,∞}(Rⁿ)的有界算子 .作为应用 ,获得了一类带齐性核的奇异积分算子交换子的L^p(Rⁿ)有界性 .     

Banach空间上有界线性算子的Drazin逆的扰动分析

设X为一复域C上的Banach空间,设T:X→X为一有界线性算子,其指标为k且R(T^k)闭.记T的Drazin逆为T^D.设T=T+δT,则在一定条件下,T^D有简明分解式T^D=T^D(I+δTT^D)^-1=(I+T^DδT)^-1T^D,从而导出了相对误差‖T^D-T^D<     

R4(C)中平均曲率方向平行的Bonnet曲面

本文利用[5]的方法,对R4(C)中平均曲率方向平行的Bonnet曲面引入了半测地等温 参数,并给出了一个分类结果.     

R13中混合型曲面保主曲率等距变形

本文研究了Minkowski空间R₁³曲面的等距变形问题.建立了R₁³中曲面的共形、等距等概念.推广了O.Bonnet和S.S.Chern关于欧氏空间的结论.对R₁³出现的新情况——曲面的中曲率梯度类光作了一定探讨,得出的主要结果为:非平坦的、允许保主曲率等距变形的曲面一定不是W-曲面.     

R_1~3中混合型曲面保主曲率等距变形

本文研究了Minkowski空间R_(1)~3曲面的等距变形问题.建立了R_(1)~3中曲面的共形、等距等概念.推广了O.Bonnet和S.S.Chern关于欧氏空间的结论.对R_(1)~3出现的新情况——曲面的中曲率梯度类光作了一定探讨,得出的主要结果为:非平坦的、允许保主曲率等距变形的曲面一定不是W-曲面.     

Tangential developable surfaces as bonnet surfaces

We study the real Bonnet surfaces which accept one unique nontrivial isometry that preserves the mean curvature, in the three-dimensional Euclidean space. We give a general criterion for these surfaces and use it to determine the tangential developable surfaces of this kind. They are determined implicitly by elliptic integrals of the third kind. Only the tangential developable surfaces of circular helices are explicit examples for which we completely determine the above unique nontrivial isometry. Dedication Dedicated to Siuping Ho for all her invaluable support and encouragement.     

Global geometry and topology of spacelike stationary surfaces in the 4-dimensional Lorentz space

For spacelike stationary (i.e. zero mean curvature) surfaces in 4-dimensional Lorentz space, one can naturally introduce two Gauss maps and a Weierstrass-type representation. In this paper we investigate the global geometry of such surfaces systematically. The total Gaussian curvature is related with the surface topology as well as the indices of the so-called good singular ends by a Gauss–Bonnet type formula. On the other hand, as shown by a family of counterexamples to Osserman?s theorem, finite total curvature no longer implies that Gauss maps extend to the ends. Interesting examples include the deformations of the classical catenoid, the helicoid, the Enneper surface, and Jorge–Meeks? k-noids. Each family of these generalizations includes embedded examples in the 4-dimensional Lorentz space, showing a sharp contrast with the 3-dimensional case.     

Bonnet Surfaces and Isothermic Surfaces

By the study of the relations between Bonnet surfaces and isothermic surfaces, we obtain classification results of Bonnet surfaces in 3-dimensional space form R³(c) and of the spacelike Bonnet surfaces in indefinite space form R₁ ³(c), which generalize the results in Bobenko’s [1] and Peng-Lu’s [11]. It is remarkable that there exist always Bonnet surfaces which are not Weingarten surfaces, if the ambient space is not R³(c) for c ≥ 0.     

Global results on Bonnet Surfaces

The local theory of the Bonnet Surfaces in the three dimensional Euclidean Space of the type of non-constant mean curvature that admit infinitely many non-trivial and geometrically distinct isometries preserving the mean curvature has been developed, in the literature, under the assumption that the surfaces contain no umbilic points and no critical points of the mean curvature function. Here, we prove that these restrictions do not create any difference from the possible global results, except in one case in which we prove that the set of the umbilic points, known to consist of exactly one point, is equal to the set of the critical points of the mean curvature function. Furthermore, we show that the index of this umbilic point, as isolated singularity of the foliation of the principal curves is one. In our proofs we use: (a) An intrinsic characterization of these surfaces, which we derive in a manner easier and including more details than those already found in the literature. From this characterization we conclude that all surfaces of this type are analytic. (b) The harmonic functions of the angles by which the respected isometries rotate the principal frames, which we compute.Dedicated to the memory of my great benefactors: my first important mathematics teacher and motivator, my uncle Michael Ioannou Roussos ( November, 1992), and his wife, my aunt Evanggelia Michael Roussou-Gavala ( May, 1994), for their invaluable support.     

Bonnet Surfaces with Constant Curvature

We classify Bonnet surfaces with constant curvature in 3-dimensional space forms and show that they are parametrized by curves in 2-dimensional space forms with specific geodesic curvature.     

On the problem of isometry of a hypersurface preserving mean curvature

The problem of determining the Bonnet hypersurfaces in R ⁿ⁺¹, for n > 1, is studied here. These hypersurfaces are by definition those that can be isometrically mapped to another hypersurface or to itself (as locus) by at least one nontrivial isometry preserving the mean curvature. The other hypersurface and/or (the locus of) itself is called Bonnet associate of the initial hypersurface. The orthogonal net which is called A-net is special and very important for our study and it is described on a hypersurface. It is proved that, non-minimal hypersurface in R ⁿ⁺¹ with no umbilical points is a Bonnet hypersurface if and only if it has an A-net.     

Complete stable CMC surfaces with empty singular set in Sasakian sub-Riemannian 3-manifolds

For constant mean curvature surfaces of class C ² immersed inside Sasakian sub-Riemannian 3-manifolds we obtain a formula for the second derivative of the area which involves horizontal analytical terms, the Webster scalar curvature of the ambient manifold, and the extrinsic shape of the surface. Then we prove classification results for complete surfaces with empty singular set which are stable, i.e., second order minima of the area under a volume constraint, inside the 3-dimensional sub-Riemannian space forms. In the first Heisenberg group we show that such a surface is a vertical plane. In the sub-Riemannian hyperbolic 3-space we give an upper bound for the mean curvature of such surfaces, and we characterize the horocylinders as the unique ones with squared mean curvature 1. Finally we deduce that any complete surface with empty singular set in the sub-Riemannian 3-sphere is unstable.