原子荧光光谱法同时测定化妆品中砷和汞

研究了原子荧光光度法同时测定化妆品中的砷和汞，并试验了硼氢化钠浓度、共存离子的影响，优化了仪器条件。方法回收率分别在：As88．7％-101．0％、Hg97．0％-107．2％之间，砷和汞的检出限分别为0．026μg／L和0．020μg／L；线性范围为As0．5—100μg／L、Hg0.5—70μg／L；RSD(n=6)As1．4％、Hg2．5％。方法具有操作简便、快速、灵敏度高等优点，可用于化妆品中As、Hg的测定。     

原子荧光光谱法测定中药中的汞

采用原子荧光光谱法测定了中药中汞，考察并优化了影响汞原子荧光强度的实验条件；提出硫脲-柠檬酸-Fe^3 作为增感剂以增强汞的荧光信号；探讨了共存离子对汞测定的干扰及其消除方法。在最佳工作条件下，方法的检出限为5．748μg／L；相对标准偏差为1．56％；线性范围为0—1000μg／L。用于6种中药样品中汞的测定，回收率为90．4％-109．6％。     

冷原子吸收光谱法测定饲料中痕量汞

本文使用汞原子发生装置与原子吸收仪联用，采用冷原子吸收光谱法测定饲料中的痕量汞，方法检出限为0.19μg/L；回收率为95％－103％；相对标准偏差为1.9%。该方法简便、准确度高、重现性好，适用于饲料中痕量汞的测定。     

冷原子荧光法测定中药中的痕量汞

本文应用冷原子荧光法，采用HNO3－H2O2的湿法消解体系，建立了中药中痕量汞的测定方法。同时，对样品的前处理方法和仪器工作条件进行了探讨和优化。在选定的实验条件下，测得检出限为0.03μg/L，用国标物质桃叶验证结果与推荐值一致；用于实际样品的测定获得了满意的结果。     

硼氢化钠还原-无色散原子荧光法测定电池中汞

建立了汞的硼氢化钠还原－无色散原子荧光测定方法,在最佳条件下,荧光强度与汞浓度在0－25ug/L范围内呈线性关系,相关系数为0．9992,检出限为0．02ug/L,用本方法测定电池中的汞,回收率为91．6－103．1％,相对标准偏差不超过4．2％。     

ICP-AES测定饮用水源中的Cu、Mn、Pb、Cd、Zn

用ICP－AES法同时测定饮用水源中的Cu、Mn、Pb、Cd、Zn等重金属元素，具有基体效应小、测量范围宽等优点。检出限为0．2－4．0μg/L，回收率为91．5％－103．9％，相对标准偏差为0．29％－1．5％，测定密码样与实际样品，结果令人满意。     

流动注射化学发光法测定头孢氨苄

基于头孢氨苄（CEX）降解产物中有还原性的巯基（SH）基团，在0．2mol/L的H2SO4介质中，能与Ce(Ⅳ）产生化学发光反应，罗丹明6G可敏化其发光强度，结合流动注射技术，考察了本体系的化学发光条件，建立了一种测定头孢氨苄的化学发光新方法。该法线性范围为0．05－10．0μg/mL，相关系数r=0.9984,检出限为0．02μg/mL，对1．0μg/mL的头孢氨苄标准溶液进行连续9次平行测定，相对标准偏差为1．4％。     

HPLC法测定硫化促进剂DM的含量

本文应用高效液相色谱法测定硫化促进剂DM的含量。采用HypersilBDS-C18色谱柱，流动相为磷酸二氢钾溶液（0．1mol/L）：乙腈＝2：3，检测波长为254nm。测定线性范围为0．16－1．4μg。     

荧光法直接测定环境水中痕量苯酚

研究了荧光分光光度通过控制酸度直接测定环境水中苯酚的新方法。在pH＝1时，直接测定苯酚的含量，波长为λex／λem＝270／297nm，检出限为4．0g/mL，线性范围为0－3．2μg/mL。回收率为99％－101％。     

超声提取-反相高效液相色谱法测定牛膝中蜕皮甾酮

比较了超声提取与回流提取法在提取牛膝中活性成分蜕皮甾酮的提取效率，在频率为1100kHz时超声提取40min可获得稳定的提取效率。采用Shim-Pack CLC-ODS色谱柱，甲醇：水＝40：60（V／V，％）为流动相，在波长248nm下，测定牛膝中蜕皮甾酮，线性范围为2－200μg/mL（r=0．9998），检出限为0．052μg/mL（S/n=3），加标加收率为98．3％－103％。     

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.