Optimizing the optical field distribution of solid immersion lens system by a continuous phase filter

In solid immersion lens (SIL) microscopy systems with high numerical aperture (NA), there always exists the aberration produced by Fresnel effects at the interface between SIL and the sample. This aberration may cause the degradation of the image of sample. We design a continuous phase filter and optimize the optical field distribution of SIL system. The numerical results show that when the continuous phase filter is used, the field distribution of SIL system can be optimized, and the focal depth and intensity of transmitted light can be increased. At the same time, the intensity of side-lobe and the resolution are kept almost unchanged.     

The Existence of Periodic Orbits for Higher Dimensional Autonomous Systemswith Small Perturbations

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A PICARD TYPE THEOREM AND BLOCH LAW

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高频单线圈双调谐NMR单晶探头的研制

本文报道了一种测角单晶NMR探头。该探头采用单线圃双调谐电路,工作频率在90MHz-110 MHz连续可调,可进行交叉极化大功率去耦实验。文中提出了一种简单而有效的测角装置,可使单晶绕三个互相垂直轴转动实现单晶的NMR测量。作为典型的应用例子,本文利用该探头实现了单晶DGO(2NH₂CH₂COOH·H₂C₂O₄)屏蔽张量的测量。     

The application of spectral distribution of product of two random matrices in the factor analysis

In the factor analysis model with large cross-section and time-series dimensions,we pro- pose a new method to estimate the number of factors.Specially if the idiosyncratic terms satisfy a linear time series model,the estimators of the parameters can be obtained in the time series model. The theoretical properties of the estimators are also explored.A simulation study and an empirical analysis are conducted.     

Thermal and chemical nanofractal relaxation

We studied shape relaxation of nano-fractal islands, during annealing, after their growth from antimony cluster deposition on graphite surface. Annealing at 180^°C shows evidence of an increase of the fractal branch width with time followed by branch fragmentation, without changing the fractal dimension. The time evolution of the width of the arm suggests the surface self-diffusion mechanism as the main relaxation process. With Monte Carlo simulations, we confirmed the observed behavior. Comparison is done with our previous results on fragmentation of nano-fractal silver islands when impurity added to the incident cluster promotes rapid fragmentation by surface self-diffusion enhancement [1].     

利用喇曼光谱测量氧碘化学激光器氯气利用率的实验研究

 介绍了利用自发喇曼散射光谱测量氧碘化学激光器单态氧发生器氯气利用率的原理及实验装置，并给出了在以氮气作为稀释气的0.1mol/s射流式氧发生器上测试的结果，测试相对误差小于12%。由于该方法只需要通过测量喇曼谱线相对强度之比，即可算出氯的利用率，因此不需要另外的标定实验，从而避免了因标定带来的影响。该方法减小了测试误差，简化了实验过程，提高了测试效率。     

Population transfer in multilevel system through modified stimulated Raman adiabatic passage

Stimulated Raman adiabatic passage (STIRAP) has been successfully extended to multilevel system. During the STIRAP process, the intermediate levels have notable population which is detrimental if these levels could decay to other levels through spontaneous emission. This paper proposes a novel method to reduce the intermediate level population during the STIRAP process. A complete population transfer can be achieved in this modified STIRAP even if the intermediate level decays to other levels.     

睾酮类兴奋剂测定中一些β-葡萄糖醛酸甙酶酶解能力的比较

睾酮是国际奥委会规定禁用的99种兴奋剂之一,由于睾酮是内源性激素,因此不能靠定性来判断运动员是否服用了睾酮,在人体激素代谢中,产生睾酮差向异构体——表睾酮,在男性黄种人中睾酮与表睾酮浓度比约为1:1,白种人中略高一些,根据这一情况,国际奥委会规定,人尿中睾酮与表睾酮之间浓度比不得超过6:1,尿中排泄出的睾酮和表睾酮是以葡