多层薄膜模型分析光纤光栅的一个新方法

光纤光栅可以看作为周期性高、低折射率相间的多层落膜叠合结构。用波动方法推导了计算这一结构总反射系数的一个新的循环公式。用这一方法计算了均匀光纤光栅布格拉格相位匹配、失配情况和非均匀光纤光栅的反射系数，并将其结果与用耦合波理论、Rouard方法以及基础矩阵方法的结果进行了比较，并检验了这些方法的精度。     

采用激光光热透射技术测量材料的热扩散率

介绍利用激光光热透射技术测量材料热扩散率的方法，用该方法测量黄铜，纯铁、铝、纯铜及锗的热扩散率，其结果与能常采用的检测手段一致。     

中草药中微量硫和汞的同时测定

用奥杰试剂还原中草药中的硫化物为S^2-，用冷原子荧光法间接测定其含量，并在测硫的同时测定了汞，其线性回归系数达到0.999986。该方法简便易行，所需试剂及干扰因素较少，灵敏度较高。     

弯曲液面上方饱和蒸汽压的初等推导

本文通过分析一个理想实验，用普通物理的方法导出了弯曲液面上方饱和蒸汽压的公式，其结果与用理论物理方法得出的完全一致，而且推导简便，物理意义明确．     

硫酸钡分光光度比浊法间接测定有机催化剂2－乙基蒽醌中的硫

本文研究了用浓硝酸将２－乙基蒽醌中的硫定量转化成硫酸根，然后用硫酸钡分光光度比浊法间接测定其硫含量的方法。建立的方法简单、快速、实用。试样分析结果表明准确度及精密度均符合要求。     

硫酸钡分光光度比浊法间接测定有机催化剂2—乙基蒽醌中的硫

本文研究了用浓硝酸将２－乙基蒽醌中的硫定量转化成硫酸根，然后用硫酸钡分光光度比浊法间接测定其在充含量的方法，建立的方法简单，快速，实用。试样分析结果表明准确度及精度均符合要求。     

用有效势方法研究一个CI相变模型

使用一个具有实际意义的双阱势作为原子间作用势、受扰余弦势作为外势，引入一个新的ＦＫ类模型，用有效势方法研究其相图，发现了一系列新奇的、复杂的，但同时又有一定规律可循的相结构。     

WKB波函数连接公式的初等推导与一维势阱势垒的WKB近似解

本文用初等方法导出ＷＫＢ波函数的连接公式，其要点是在转折点邻近，用阶跃型势能曲线代替真实的势能曲线。给出了求一维势阱能级及一维势垒穿透因子的方法与结果。方法简便，可供初等量子力学与普通物理教学参考。     

浊度计快速测定苯乙烯单体中聚合物的研究

建立了用浊度计快速测定苯乙烯单体中聚合物的方法，样品用甲醇溶解后，以样品／正己烷溶液为空白，通过测定其浊度，确定聚合物的含量。消除了GB／T 12688．3-1990用光度法测定聚合物过程中空白基体的影响。在0-50mg／kg范围内线性关系良好，相关系数r=0．9991，检出限达到0．01mg／kg，方法简便、快速，完全能达到实际检测要求。     

带阻性负载细导线对电磁脉冲响应的有限差分算法

在原始的FDTD细线算法基础上，把带负载细导线模型分成导线、电阻和吸收三个部分，分别用不同的偏微分方程描述，使其可以处理两端带有纯电阻性负载细线电磁脉冲散射问题，进而得到电阻负载上消耗的总能量及对应的功率消耗。用该方法计算得到的结果与文献结果进行了比较，证明了该方法的有效性。最后用此方法对一种典型情况进行了计算，并对结果进行了分析。该方法是对FDTD方法中细线算法的补充和提高，经过修改也可以用于非阻性负载的情况。     

Self-organization of five species in a cyclic competition game

Cyclic competition game models, particularly the “rock–paper–scissors” model, play important roles in exploring the problem of multi-species coexistence in spatially ecological systems. We propose an extended “rock–paper–scissors” game to model cyclic interactions among five species, and find that two of the five can coexistent when biodiversity disappears, which is different from the “rock–paper–scissors” game. As the number of fingers is five, we named the new model the “fingers” game, where the thumb, forefinger, middle finger, ring finger, and little finger cyclically dominate their subsequent species and are dominated by their former species. We investigate the “fingers” model in two ways: direct simulations and nonlinear partial differential equations. An important finding is that the number of species in a cyclic competition game has an influence on the emergence of biodiversity. To be specific, the “rock–paper–scissors” model is in favor of maintaining biodiversity in comparison with the “fingers” model when the variables (population size, reproduction rate, selection rate, and migration rate) are the same. It is also shown that the mobility and reproduction rate can promote or jeopardize biodiversity.     

Contrastive analysis on tone between Putonghua and Taiwan Mandarin

The differences of the pitch and duration of Chinese syllables between Putonghua （PTH） and Taiwan Mandarin （TM） were studied. The speech materials to be used are not only isolated syllables, but also sentences. The results reveal that： For the isolated syllables, T1 and T2 in TM are influenced by Minnan dialect, therefore their pitch are lower than those in PTH. T3 is fall-rise in PTH, while it is fall in TM. Moreover, the syllable duration sequence for different tone is T3〉T2〉T1〉T4 in PTH, while it is T1〉T2〉T3〉T4 in TM. For the syllables in sentences, T2 is mid-rise in PTH, while it is mid-level in TM. And the T3 is longer than T4 but shorter than T1 or T2 in PTH, while it is the shortest in TM. Furthermore the effects of prosodic phrase boundary on duration for different tones are almost the same in PTH, but the lengthening part of T1 or T2 is longer than that of T3 or T4 in TM.     

Experimental study on downstep in Chinese intonation

Downstep in pitch contour of Chinese Putonghua is examined using subtly designed sentences by controlling tone combinations. The results show both automatic and nonautomatic downstep phenomena exist in Chinese. In non-automatic downstep, low tones compress downwards the pitch range of the following syllables. and the main influence of downstep is on topline. Low tone not only lower the topline behind it, but also raise the high tones before it, the effects are compatible with each other. In automatic downstep, the topline of pitch contour in intonational phrase is presented as a linear downtrend, but it differs among speakers due to the effect of personal stress practice. In comparison with downstep phenomenon in other tone or non-tone languages, the downstep ratio in Chinese is not constant, and the domain of downstep is not limited within the adjacent tones.     

Abelian-Higgs phase of SU(2) QCD and glueball energy

It is shown that SU(2) QCD admits an dual Abelian-Higgs phase, with a Higgs vacuum of a type-Ⅱ superconductor. This is done by using a connection decomposition for the gluon field and the random-direction approximation. Using a bag picture with soft wall, we presented a calculational procedure for the glueball energy based on the recent proof for wall-vortices [Nucl. Phys. B 741(2006)1].     

Theoretical analysis and simulation of conjugate heights for dual-conjugate AO system in lidar

A multi-conjugate adaptive optics （MCAO） can offer a possibility of widening field of view （FOV） characterized by the isoplanatic angle, and the choose of conjugate height becomes a basic problem for MCAO, which influences the size of iosplanatic angle. Considering the application of lidar, the isoplanatic angle＇s expressions of two deformable mirrors （DMs） MCAO for uplink and downlink are deduced. The effects of conjugate heights for dual-conjugate AO are thoughtfully discussed, and the isoplanatic angles are further analyzed. The results show that the isopanatic angle varies with the conjugate height and reaches the maximum as the conjugate height is at the optimal altitude. Moreover, the optimal conjugate height changes with the propagation distance.     

Quick single-photon detector with many avalanche photo diodes working on the time division

Due to the limit of response speed of the present single-photon detector, the code rate is still too low to come into practical use for the present quantum key distribution (QKD) system.A new idea is put up to design a quick single-photon detector.This quick single-photon detector is composed of a multi-port optic-fiber splitter and many avalanche photo diodes (APDs).Au of the ports with APDs work on the time division and cooperate with a logic discriminating and deciding unit driven by the clock signal.The operation frequency lies on the number N of ports, and can reach N times of the conventional single-photon detector.The single-photon prompt detection can come true for high repetition-rate pulses.The applying of this detector will largely raise the code rate of the QKD, and boost the commercial use.     

Signal generation in an isotropic medium in scanning electron acoustic microscope

Based on the research in Ref. [5][Materials Science and Engineering, 1989; A122： 57 63], an improved model of heat source is set up, the different modes of Lamb wave in an isotropic sample generated by a chopped electron beam at frequency f are obtained with integral transform and normal function expansion method, and the output signal of PZT coupled at the back surface of the sample is found out. The generation mechanism of SEAM （Scanning Electron Acoustic Microscopy） signal is discussed. It shows that the SEAM is a near field imaging technique with high spatial resolution and its best lateral spatial resolution is about 2√2α （α is the radius of the focused electron beam）. Some of experimental results of SEAM images are presented in the paper and it shows that the spatial resolution of SEAM is better than 0.5 μm and smaller than the thermal diffusion length of the sample. Therefore the character of near field imaging in SEAM is also proved experimentally.     

High efficiency filtering using two-dimensional photonic crystal coupled cavity structures

Transmission spectra of coupled cavity structures (CCSs) in two-dimensional (2D) photonic crystals (PCs) are investigated using a coupled mode theory, and an optical filter based on CCS is proposed. The performance of the filter is investigated using finite-difference time-domain (FDTD) method, and the results show that within a very short coupling distance of about 3λ, where λ is the wavelength of signal in vacuum, the incident signals with different frequencies are separated into different channels with a contrast ratio of 20 dB. The advantages of this kind of filter are small size and easily tunable operation frequencies.