气体靶激光等离子体软X-射线源实验研究

介绍了一种无碎屑、高亮度、高工作频率的气体靶激光等离子体软X 射线源。其喷气阀门由压电陶瓷驱动 ,工作频率可达到 40 0Hz。与金属靶激光等离子体软X 射线源相比 ,此光源无碎屑。与喷嘴由电磁阀控制的气体靶激光等离子体软X 射线源相比 ,它有较高的工作频率。一工作在模拟模式的通道电子倍增器被用于探测来自光源的软X 射线辐射 ,其输出信号经过一电荷灵敏前置放大器进一步放大变成电压脉冲信号 ,脉冲幅度与输入电荷灵敏前置放大器的电量成正比。实验测得CO2 ,Xe和Kr在 8～ 2 2nm软X 射线投影光刻常用波段的光谱辐射特性。CO2 光谱包括类锂和类铍离子跃迁形成的线谱 ,Xe光谱是多电荷氙离子 4d 5f,4d 4f,4d 6p和 4d 5p跃迁所形成的光谱。Kr气体靶光谱包括类铜离子、类镍离子、类钴离子和类铁离子跃迁形成的线谱和连续谱。     

Periodic Solutions of a Model of Mitosis in Prog Eggs

In this paper,we discuss a simplified model of mitosis in frog eggs proposed by M.T. Borisuk and J.J. Tyson in [1]. By using rigorous qualitative analysis, we prove the existence of the periodic solutions on a large scale and present the space region of the periodic solutions and the parameter region coresponding to the periodic solution. We also present the space region and the parameter region where there are no periodic solutions. The results are in accordance with the numerical results in [1] up to the qualitative property.     

掺锌LiNbO3晶体的生长及其光学性能

在LiNbO₃中掺进3mol%、5mol%、7mol%ZnO生长Zn:LiNbO₃晶体.测试Zn:LiNbO₃晶体的吸收光谱,研究Zn:LiNbO₃晶体吸收边紫移的机制.测试Zn:LiNbO₃晶体的红外光谱,研究Zn(7mol%):LiNbO₃晶体OH 吸收峰由3484cm^-1移到3530cm^-1的机制.测试Zn:LiNbO₃晶体倍频转换效率和相位匹配温度,研究Zn:LiNbO₃晶体倍频转换效率增强的机制.     

具非线性对流项扩散方程的源型解

研究主部为热传导算子的拟线性抛物型方程Cauchy问题:u_t=u_(xx) (u~n)_x,(x,t)∈S=R×(0,∞),u(x,0)=δ(x),x∈■在一维情形下源型解的存在性,唯一性,不存在性,解的渐近性和相似源型解等问题.在研究过程中,找到了一个n的临界值,即n_0=3.当0≤n相似文献   

卟啉取代侧链在LB膜结构中的取向研究

本文研究了５，１０，１５，２０－四（对－山嵛酸乙酯－α－氧代苯基）卟啉在气－液界面的成膜性能。在优化实验条件下制备了该化合物的多层ＬＢ膜。利用偏振ＦＴ－ＩＲ谱测定了卟啉上脂链取代基在ＬＢ膜结构中的取向。结果表明脂链轴线与载片法线间夹角为２７°。     

天然水中微量稀土元素镧的流动注射在线预浓集ICP光谱法测定

本文采用P507萃淋树脂为固定相,应用流动注射(FI)在线预浓集技术,建立了镧的ICP发射光谱分析方法,对天然水中的微量镧进行了测定,获得满意结果。     

A Novel Synthesis of (-)-10-epi-α-Cyperone

The eudesmane derivative, (-)-10-epi-α-cyperone 1, is widely used as a chiral starting material for the synthesis of other fused-ring sesquiterpenes1. The first synthetic work was reported by Howe and co-workers via condensation of (+)-dihydrocarvone 2 with 1-diethylaminopentan-3-one methiodide in 32% yield2. Previously, our group reported the synthesis of compound 1 by treating ketone 2 with ethyl vinyl ketone (EVK) directly under different conditions1a, but the yields were not satisfacto…     

THE UPWIND FINITE ELEMENT SCHEME AND MAXIMUM PRINCIPLE FOR NONLINEAR CONVECTION-DIFFUSION PROBLEM

In this paper, a kind of partial upwind finite element scheme is studied for twodimensional nonlinear convection-diffusion problem. Nonlinear convection term approximated by partial upwind finite element method considered over a mesh dual to the triangular grid, whereas the nonlinear diffusion term approximated by Galerkin method. A linearized partial upwind finite element scheme and a higher order accuracy scheme are constructed respectively. It is shown that the numerical solutions of these schemes preserve discrete maximum principle. The convergence and error estimate are also given for both schemes under some assumptions. The numerical results show that these partial upwind finite element scheme are feasible and accurate.     

Spectroscopic Studies on Charge Transfer from Ce~(3 ) to Yb~(3 ) in KMgF_3∶Ce,Yb Nanocrystals

Nanocrystals of KMgF3 single-doped and codoped with Ce3 or/and Yb3 were synthesized separately by the microemulsion method.The X-ray diffraction(XRD)patterns were indexed to show that the KMgF3 crystal system was unchanged.The fluorescent spectra of KMgF3∶Ce,Yb polycrystal powders were studied and compared with those of the Ce,Yb doped KMgF3 crystals produced using the high-temperature solid phase method.The diffuse reflection spectra and infrared emission of KMgF3∶Ce,Yb were investigated.From the results,the authors could confirm that there were charge transfer processes from Ce3 to Yb3 in both KMgF3∶Ce,Yb nanocrystals and polycrystal powders.     

Photochemically Catalyzed Diels-Alder Reaction of Azadienes with 2,3-Dihydrofuran by 2, 4, 6-Triphenylpyrylium Salt： Synthesis of Styrylfuroquinoline Derivatives

Photochemically promoted Diels-Alder reactions of 1, 4-diaryl-1-azabutadienes with 2,3-dihydrofuran were achieved by using 2, 4, 6-triphenylpyrylium tetrafluoroborate as catalyst to produce corresponding styrylfuroquinolines in high yield.