Systematic considerations for the patterning of photonic crystal devices by electron beam lithography

Photonic crystal devices with feature sizes of a few hundred nanometers are often fabricated by electron beam lithography. The proximity effect, stitching error and resist profiles have significant influence on the pattern quality, and therefore determine the optical properties of the devices. In this paper, detailed analyses and simple solutions to these problems are presented. The proximity effect is corrected by the introduction of a compensating dose. The influence of the stitching error is alleviated by replacing the original access waveguides with taper-added waveguides, and the taper parameters are also discussed to get the optimal choice. It is demonstrated experimentally that patterns exposed with different doses have almost the same edge-profiles in the resist for the same development time, and that optimized etching conditions can improve the wall angle of the holes in the substrate remarkably.     

Periodic solutions of second order non-autonomous Hamiltonian systems with local superquadratic potential

Some existence theorems are obtained for periodic solutions of a class of non-autonomous second order Hamiltonian systems with local superquadratic potential, by making use of the generalized mountain pass theorem.     

一类奇摄动系统奇异极限环的不变环面分支

对一类奇异摄动系统中由奇异极限环产生的不变环面分支进行了研究并利用不变环面的分支理论,讨论了由快系统的二重极限环和三重环分支出的不变环面的存在性．     

正交频分复用系统中带比例公平的功率分配算法

针对传统多用户正交频分复用（OFDM）系统中比特和功率分配算法计算复杂度较高、实时性不强、无法保证用户间公平性等问题，提出了一种下行OFDM传输中高效率的线性比特和功率分配算法．该算法能在保证每个用户误比特率（BER）和数据速率要求下，按比例分配用户容量，使总发射功率最小．计算机仿真结果表明，该算法和传统资源分配算法相比，复杂度较小，系统容量在用户间分配得更加公平和合理．     

Study on an improved phase-shifting five-interferogram algorithm

Using traditional five-interferogram algorithm to unwrap phase for length measurement, the phase steps must be equal to π/2 exactly, but it is almost impossible to achieve in nanometer positioning technique. Aiming to overcome this defect of traditional five-interferogram algorithm, an improved five-interferogram algorithm is presented. This improved algorithm not only keeps the high accuracy of traditional fiveinterferogram algorithm, but also does not need absolute equal step to unwrap phase. Instead, this algorithm only needs measuring phase-shifting. With the numerical simulation, the improved five-interferogram algorithm shows high accuracy, high reliability, and feasibility in practice. It is very valuable for accurate length measurement with Fizeau interferometer and Fabry-Perot interferometer.     

水溶液中N-烷基亚胺二乙酸二氨铂(Ⅱ)配合物的13C NMR研究

在不同pH条件下以N-烷基亚胺二乙酸[R-N (CH₂COOH)₂,R=Me,i-Pr,n-Pr,HO-Et]为配体合成了一系列二氨铂(Ⅱ)类配合物.¹³C NMR (20MHz)研究结果表明该类配体均以N、O与铂配位,配位方式不随合成时pH值的改变而改变,在弱酸条件下,配合物处于交换平衡状态,平衡常数由不同pH下未配位羧基碳的化学位移计算而得.     

46.7MeV/u 12C诱发核反应中的双质子干涉研究

本文讨论了46.7MeV/u ¹²C+⁵⁸Ni,¹¹⁵In,¹⁹⁷An实验中双质子干涉的研究结果,研究了零寿命Koonin模型中核力、库仑力及费米统计对关联函数的影响,并从实验中提取了发射源的半径参数r₀,实验发现r₀随着靶核质量的增加而增加,实验中还研究了发射源的大小与两个关联粒子能量和E₁+M₂的关系,得出的r₀值随着E₁+E₂的增加而减少,反映了高能质子主要来源于反应的早期.     

香草醛的极谱行为研究

研究了香草醛的极谱吸附波．香草醛与硫酸联氨在酸性介质中发生反应，其产物在示波极谱仪上可观察到一个灵敏的二阶导数吸附还原波．峰电位为－１．０９Ｖ（ｖｓ．ＳＣＥ）．浓度在２．００×１０－５～１．００×１０－７ｍｏｌ·Ｌ－１范围内，导数峰高呈良好的线性关系．检测下限为５．００×１０－８ｍｏｌ·Ｌ－１．本方法可用于测定水中的香草醛．还探讨了香草醛的极谱行为和电极反应机理．     

25MeV/u~(40)Ar ~(93)Nb反应中热核的激发能和核温度

利用半导体望远镜探测器和ＰＰＡＣ对２５ＭｅＶ／ｕ４０Ａｒ＋９３Ｎｂ反应中的带电粒子和余核进行了关联测量，对所得α粒子能谱用三源模型进行了拟合，并由余核飞行时间和粒子多重性得到热核激发能．通过对温度的修正，发现在本实验中有激发能Ｅ＊／Ａ为４．３ＭｅＶ，温度Ｔｉｎｉｔ为６．９ＭｅＶ的热核形成。通过与其它实验结果的对比可以看出核物质在轻系统和重系统中行为的差异。     

模糊时间序列模型的辨识

可能性线性系统的输出时间序列可用模糊数来表示，我们称其为模糊时间序列（ＦＴＳ），这篇论文提出了ＦＴＳ分析的新方法，并研究它的参数估计和模型定价。两个仿真例子表明本文提出的方法对ＦＴＳ分析是非常有效的。