载能团簇离子诱发的非线性二次离子发射

载能团簇离子进入固体时， 由于集体相互作用，在入射路径上产生非常高的能量沉积密度。 实验发现， 载能团簇离子的作用结果并不等于团簇中各原子独立作用的总和， 而是具有非线性效应。 就二次离子发射而言， 这种非线性通常与团簇的能量、 团簇的大小、 离子的电荷态以及靶物质的结构有关。 通过研究二次离子发射有助于理解载能团簇离子与物质相互作用过程中的能量沉积与释放机制。 Using energetic cluster as projectile is a unique way to produce simultaneous impacts of several atoms and deposit extremely high energy density in a very small area. The cluster impingement on solids has exhibited some non linear effects not presented in collisions of individual atoms with those solids. The study of the secondary ion emissions can give insight into the energy deposition and relaxation steps of the cluster solid interaction. The dependence of the yields of secondary ion emission induced by clusters on the energy of clusters,cluster sizes,charge states and material structures of the targets was reviewed in this paper.     

左联合谱的一个刻划及其应用

In this paper we characterize the left joint spectrum of an n-tuple T =(T1,... ,Tn) of dominant bounded linear operators on a complex Hilbert space H and the unital C^*-algebra C^*(T) generated by T1,… , Tn and I; moreover, we give an application of this characterization.     

载能团簇离子在物质中的能量损失

实验表明，团簇离子在物质中的能量损失并不等于各成分单独作用的总和，而是具有非线性效应．这种非线性效应与团簇离子的能量、团簇的种类和大小、团簇成分之间的空间关联程度以及作用物质的结构有关．对团簇作用的非线性效应研究对于了解团簇与物质相互作用的机制具有非常重要的理论意义．MeV能区的团簇离子在物质中的非线性电子能损和核能损方面的直接实验数据还相当缺乏，其理论模型也更待建立．评述了载能团簇离子在物质中的能量损失及测量方法．Fast ions deposit energy in matter through electronic and nuclear collision processes. The relaxation of the deposited energy induces emission of photons, electrons, ions, and neutral species from the target. Comparing with single incident ion, cluster induces many new phenomena: such as non-linear energy loss, non-linear emission of secondary ions, production of giant tracks and craters in various irradiated materials. These new phenomena induced by clusters are attributed to the vicinage effect ......     

铷原子气体自旋噪声谱的测量与改进

利用自主设计并制作的基于现场可编程门阵列的实时傅里叶变换采集卡(FFTsDAC),采用线偏振光检测碱金属铷原子气样品中的自旋随机涨落(即自旋噪声谱).详细讨论了背景噪声以及自旋噪声随探测光光强的变化关系,证实了自旋噪声来自于系统中自旋的随机涨落.对比了两种FFTsDAC(8 bit采样的FFTsDACl和12 bit采样的FFTsDAC2)的测量性能,分析了影响实验信噪比的因素.FFTsDAC2具有更高的测量效率和采样深度以及更长的单次采样时间,因而具有更高的信噪比和更好的频率分辨率,与数值模拟的结果一致.     

载能团簇离子的非线性辐照损伤

由于团簇离子在能量损失、二次离子发射和辐照损伤上的非线性效应，所以团簇离子与物质的相互作用倍受关注。对团簇作用的非线性效应研究不仅对于了解团簇离子与物质相互作用的机制具有十分重要的理论意义，而且载能团簇离子还有可能成为材料表面改性与分析、新功能材料的合成与研究的一种有效的新手段。因此，团簇离子与物质的相互作用成为当今国际上的研究热点之一。主要评述了载能团簇离子在物质中的非线性辐照损伤，介绍了典型的研究方法和实验结果。 Due to energetic cluster produces simultaneous impacts of several atoms and deposits extremely high energy density in a very small area, the cluster impingement on solids has produced non-linear radiation damages not presented in the collisions of individual atoms with those solids. The radiation damages are usually investigated by channeling Rutherford backscattering, Scanning Tunneling Microscope （STM）, Transmission Electronic c Microscope（TEM） and computer simulation. The typical methods and results on the non-linear radiation damages induced by clusters are reviewed in this paper.     

加速器束流脉冲化及氢二次离子发射研究

详细介绍了快速高压晶体管开关在加速器束流脉冲化和用于二次离子测量的加速器飞行时间谱仪上的应用. 利用飞行时间法研究了碳纳米管在不同能量的Si和Si2团簇离子轰击下氢二次离子的发射. 实验结果表明， 在每个原子质量单位的速度为2.5×108 cm/s以上， Si和Si2离子引起的氢二次离子的发射主要受电子阻止过程控制； 在每个原子质量单位的速度为2.5×108 cm/s以下和Si2团簇离子轰击的情况下， 氢二次离子的发射产额明显增加， 团簇离子在靶表面的核能损增强效应起主要作用. The application of Fast High Voltage Transistor Switches (HTS) in pulsed ion beam and the time of flight(TOF ) setup is described. Secondary ion emissions from carbon nanotubes under bombardments of MeV Si and Si2 clusters are measured by using TOF. The measurements indicate that the yield of the secondary ion emissions of hydrogen increases with increasing energy of Si and it is attributed to the electronic processes. The yield of the secondary ions of hydrogen decreases with increasing energy of Si2 clusters and the enhancement of nuclear energy loss of cluster constituents at the surface of sample plays a more significant role in the secondary ion emission of hydrogen at the low energies.     

Banach流形上一类非线性方程的解集的结构

设f是两个Ck(k≥1)Banach流形M和Ⅳ之间的C1映射.由f定义M上的一个三重指标(M(x),Mc(x),Mr(x)),用此三重指标刻画了f的局部精细点.同时当y是f的广义正则值时,获得原像f-1(y)中含x0的连通分支是M中一个具有维数为M(x0)的C1Banach子流形.特别地,给出非线性方程f(x)=y的孤立解的一个特征.     

A RANK THEOREM FOR NONLINEAR SEMI-FREDHOLM OPERATORS BETWEEN TWO BANACH MANIFOLDS

In this article the concept of local conjugation of a C1 mapping between two Banach manifolds is introduced. Then a rank theorem for nonlinear semi-Fredholm operators between two Banach manifolds and a finite rank theorem are established in global analysis.     

Banach流形上一类非线性方程的解集的结构

设f是两个Ck(k≥1)Banach流形M和N之间的C1映射.由f定义M上的一个三重指标(M(x),Mc(x),Mr(x)),用此三重指标刻画了f的局部精细点.同时当y是f的广义正则值时,获得原像f-1(y)中含xo的连通分支是M中一个具有维数为M(xo)的C1Banach子流形.特别地,给出非线性方程f(x)=y的孤立解的一个特征.     

A Note on a Problem of M. S. Berger

In this paper, we discuss the problem concerning global and local structure of solutions of an operator equation posed by M. S. Berger. Let f : U (?)E→ F be a C1 map, where E and F are Banach spaces and U is open in E. We show that the solution set of the equation f(x)=y for a fixed generalized regular value y of f is represented as a union of disjoint connected C1 Banach submanifolds of U, each of which has a dimension and its tangent space is given. In particular, a characterization of the isolated solutions of the equation f(x) = y is obtained.