电离作用

Through comparing the Ar (e,3e) double ionization experimental results at low collision energy with the theoretical calculation based on the first Born approximation which include the first order mechanisms SO and TS1, the symmetry breaking about the direction of the momentum transfer shows that the non-first order effects (such as two-step 2 mechanism) play an important role.

通过比较Ar在低碰撞能量下的(e ，3e)双电离实验结果和基于包含一次作用机制SO和TS1的一阶波恩近似的理论计算结果，表明在动量转移方向上对称性的破坏显示非一次效应(例如二型两步作用机制)起非常重要的作用。

With this model, we achieve insight into the ion momentum distribution under the combined influence of a two-center Coulomb potential and an intense laser field, and our result shows the significant influence of molecular alignment on the ratio between double and single ionization rate.

研究中我们考察了双中心库仑势及外加场共同作用下的离子动量分布，计算结果同样给出了分子取向对双电离和单电离比率的影响。

Objective To study the protective effect of glutamine on antioxidation in mice damaged by radiation.

目的 研究谷氨酰胺对电离辐射损伤小鼠抗氧化作用的影响，探讨Gln的辐射防护作用机制。

Main contents and conclusions are: 1 The ionization current was measured continuously by a charge-integration method with a computer after the introduction of radon into the chamber.

主要内容及结论：1充氡后利用计算机连续进行电离电流累积测量，得到了精细的电流随时间的变化曲线，可清楚看出氡及其子体的生成衰变造成的电离电流的生长—稳定—衰减过程，与理论计算值进行了比较，由电离电流衰减速度的变化得出氡吸附作用的影响，并测量到电离室冲洗后氡的反扩散现象；2由已知活度的标准源定出相对测量的刻度系数K值，K=24.62 Bq／pA，对同一个监测源以半年为周期进行多次测量后得出稳定性符合要求；3通过测量电离电流和气压的关系曲线以及不同气压下的饱和曲线，确定了常规的工作条件；4测量了盐酸清洗电离室内表面降低本底的效果；5不确定度分析表明相对测氡的扩展不确定度(k=2)小于5％，由本底涨落得出探测下限为0.5 Bq；6理论上对壁损失修正进行了计算，实验上保持电离室工作在饱和区的情况下，测量了不同气压下电离电流的变化，从中得出了壁损失随气压变化的规律，可以看出，电离电流的实测值和计算值随气压变化规律基本一致；当气压大于125 kPa时，端效应等其它因素造成的影响不大于2％，因而在此工作条件下，测量电离电流后通过计算修正壁损失可以实现近似的绝对测氡，提出了进一步提高绝对测量准确度的方法。

It has been found that the ionization processes are determined by hollow cathode effect and local electric field.

通过研究电离过程的细节，可以认为该阶段电离过程是空心阴极效应和局部强电场共同作用的结果。

The threshold of lithium tantalite under single-shot is found to be 1.84J /cm 2 and the avalanche rate was determined to be 1.01 cm 2 /J by calculation. We found that avalanche dominates the ablation process, while photoionization serves as a free electron provider.

在800nm飞秒激光脉冲作用下，钽酸锂晶体单脉冲烧蚀阈值为1.84 J /cm 2；在此基础上，我们通过建立钽酸锂晶体中导带电子密度演化微分方程，并数值求解，得到了钽酸锂的碰撞电离速率系数为1.01 cm 2 /J ，并得出在钽酸锂表面烧蚀中，光致电离提供种子电子，雪崩电离起主导作用的结论。

It is found that both the total and differential cross sections increase with the increasing of screening interaction, and especially for energies below 10 keV/u, the cross sections are one to two magnitudes larger than those in the unscreened case.

研究发现，碰撞电离总截面随等离子屏蔽的增加而增大，特别是在10 keV/u以下的低能区电离截面有量级的增加。对随能量变化的一阶微分截面，在低能碰撞过程中，屏蔽作用增加，微分截面呈量级增加，高能碰撞微分截面呈倍数增加。

The mechanism of multiple-ionization is analyzed. The highly charged recoil ions come mainly from the Auger effect. The electron-electron interaction comes in to effect as the incident energy increases.

对多重电离的电离机制分析表明：高价态的反冲离子主要来自于俄歇贡献；随着入射能量的升高，电子-电子间的库仑作用也逐渐显现。

In this paper we address the question of the transition between autoionization that prevails in small molecules, and delayed ionization occurring in larger molecules or clusters. This transition is illustrated by autoionization of Na2 Rydberg states on one hand, delayed ionization in fullerene C60, and delayed detachment in small cluster anions on the other hand.

本文通过Na2的里德堡态的自电离，富勒烯C60的延迟电离，阴离子小团簇的延迟解离研究了在小分子中起主导作用的自电离和在大分子以及团簇中出现的延迟电离之间的转变过程。

It shows that The correlation between the two outgoing electron and the ion play a more important role in the mechanism of this ionization. 2. The auger and the autoionization process of the inner shell are theindirect processes of the ionization that correspond the relaxation and the double excitation of the inner shell. Taouil et 〓 guesses that these processes are included in the mechanism of the ionization. The present theoretical results showthat the influences on the inner shell ionization of these processes are notimportant.

说明在内壳层的高非对称的动能区域，被电离电子与离子以及末态两个电子之间的角关联在这个电离动力学机制中扮演了重要的作用 2、内壳层的饿歇过程和自电离过程为间接电离过程，对应于碰后相互作用的离子弛豫和内壳层的双激发，Taouil et al的实验〓认为包括在电离的机制，我们的计算表明它们对内壳层(e，2e)反应的影响并不很重要。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。