西咪替丁与氯醌酸荷移反应的研究

研究了西咪替丁与氯醌酸的荷移反应。确定了形成电荷转移络合物的最佳反应条件。在丙酮介质中,电子给体西咪替丁与电子受体氯醌酸于室温下可形成1：1的荷移络合物,络合物的最大吸收波长为516.6nm;表观摩尔吸光系数ε=2.22×103L.mol-1.cm-1;线性范围为6.8—112.0μg/mL;相关系数r为0.9995;并对形成荷移络合物的反应机理进行了探讨,并应用拟定的方法对样品西咪替丁片剂进行了含量测定,回收率为99.44%—100.20%;RSD为1.3%。     

阿奇霉素含量的荷移光谱法测定

用分光光度法分别研究了阿奇霉素与7,7,8,8-四氰基对二次甲基苯醌(TCNQ)和氯冉酸(CL)之间的荷移反应。实验表明：阿奇霉素与TCNQ间的反应在丙酮介质中进行,形成的络合物在743和842 nm有两个吸收峰,表观摩尔吸光系数分别是2.7×104 L·mol-1·cm-1和5.0×104 L·mol-1·cm-1;阿奇霉素与氯冉酸的反应在丙酮介质中进行,形成的络合物在530 nm处有吸收峰,表观摩尔吸光系数2.4×103 L·mol-1·cm-1。用摩尔比法和等摩尔连续变化法测得荷移络合物中阿奇霉素与配体的摩尔比均为1∶2。用以上两种方法测定了阿奇霉素片剂中阿奇霉素的含量,相对标准偏差为1.0%～1.4%(n=6),回收率为97%以上,与标准方法比较结果准确。     

荷移络合物分光光度法测定头孢噻肟钠的研究

研究了头孢噻肟钠与对苯醌(p-BQ)的荷移反应.确定了形成电荷转移络合物的最佳反应条件.在硼砂介质中,电子给予体头孢噻肟钠与电子接受体对苯醌于室温下可形成1:2的荷移络合物,络合物的最大吸收波长为587.5nm;表观摩尔吸光系数ε=9.92×103L·mol-1·cm-1;线性范围为2-36μg/mL;对形成荷移络合物...     

奥美拉唑与氯冉酸的荷移反应及其测定

奥美拉唑 (电子给予体 )与氯冉酸 (电子接受体 )在丙酮介质中生成 1∶ 1型荷移络合物 ,在波长5 2 5 nm处有最大吸收 ,表观摩尔吸光系数是 1.0 2× 10 3 L· mol-1·cm-1。依据此荷移反应建立了一种快速测定奥美拉唑的荷移分光光度法。药物浓度在 2 0— 30 0 mg/ L范围内服从比耳定律。 6次测定结果的相对标准偏差为 0 .4 8% ,利用本法测定了奥美拉唑胶囊中有效成分的含量 ,结果令人满意。     

氯冉酸为受体的荷移荧光光谱法测定洛美沙星

研究了电子受体氯冉酸与电子给体洛美沙星之间的荷移反应。实验结果表明 :在丙酮 甲醇介质中于室温下即可生成稳定的n π络合物 ,其荧光发射较洛美沙星有显著的增敏效应。研究并优化了影响反应的不同的条件和参数 ,据此建立了一种基于荷移反应简便可靠地测定洛美沙星的荧光光谱新方法 ,同时还研究了药物制剂的共存体的干扰 ,该方法已成功地用于纯品和制剂中洛美沙星含量的测定 ,其准确度和精密度令人满意。最低检出限为 0 0 4mg·L-1,回收率为 97 4 %～ 99 3% ,相对标准偏差为 1 3%～ 2 6 %。还对荷移反应的机理进行了探讨。     

替米沙坦与氯冉酸的荷移反应

用分光光度法研究了替米沙坦与氯冉酸的电荷转移反应条件,替米沙坦与氯冉酸在丙酮溶液中可以发生电荷转移反应,在室温下按实验方法配好溶液即可比色。电荷转移络合物的最大吸收波长是525nm,表观摩尔吸光系数为2.18×10²L·mol^-1·cm^-1。替米沙坦质量浓度在16—192mg·L^-1范围内服从比耳定律,相关系数为0.9997。当替米沙坦浓度为80mg·L^-1时,六次测定结果的相对标准偏差为1.33%,回收率在99.0%以上。测得荷移络合物的组成和稳定常数分别为1:2和3.9×10⁷。用于测定制剂中替米沙坦的含量结果令人满意。     

甲磺酸培氟沙星与氯冉酸的荷移反应

利用甲磺酸培氟沙星与氯冉酸在甲醇介质发生荷移反应,建立了荷移分光光度法测定甲磺酸培氟沙星含量的方法。结果表明,荷移反应生成1∶1型配合物,最大吸收波长为530nm,甲磺酸培氟沙星线性范围为2.25×10-8—3.38×10-6mol/L浓度内,回收率为98.7%—101.4%。     

甲硫氨酸与2,3-二氯-5,6-二氰-1,4-苯醌的荷移反应

用分光光度法研究了甲硫氨酸与2,3-二氯-5,6-二氰-1.4-苯醌(DDBQ)的荷移反应.实验表明,在pH=9.0三酸缓冲溶液中,在50℃水浴中加热30min,两者可形成稳定的1:1型的荷移络合物.此络合物的λmax343nm,表观摩尔吸光系数ε=1.4×104L·mol-1·cm-1,在0.4-15.0μg/mL范围内符合比耳定律,回收率在98.24%-101.1%,相对标准偏差为0.89%-0.95%.     

盐酸雷尼替丁与7,7,8,8-四氰基对二次甲基苯醌荷移反应的研究

以盐酸雷尼替丁为电子给体,7,7,8,8-四氰基对二次甲基苯醌(TCNQ)为电子受体,研究了它们之间形成电荷转移络合物的最佳条件.结果表明:在丙酮介质中,二者于50℃下60min即可形成1:1络合物,室温下至少稳定4h.荷移络合物的最大吸收波长为845nm,表观摩尔吸光系数为1.70×104L·mol-1·cm-1,在1-20mg·L-1范围内符合比耳定律.基于以上反应建立本方法,用于测定制剂中盐酸雷尼替丁的含量,结果与药典方法一致,回收率为99.27%-101.40%,相对标准偏差为1.56%(n=10).     

氟罗沙星荷移络合物在胶束体系中的紫外光谱特性及应用

采用紫外光谱法研究了π电子受体四氯对苯醌(TCBQ)与电子供体氟罗沙星的荷移反应,结果表明,氟罗沙星与TCBQ在十二烷基硫酸钠(SDS)胶束体系中能形成稳定的荷移反应络合物,使其吸光度明显增强。据此建立了氟罗沙星简单、快速、准确和灵敏的分析方法。氟罗沙星浓度在0. 6～24 mg·L-1范围内符合比尔定律。r= 0.999 3。荷移络合物在326 nm处的表观摩尔吸光系数为3.3×104 L·mol-1·cm-1。本方法用于片剂中氟罗沙星含量的测定, 其回收率为99.3%～99.8%, 相对标准偏差为0.9%～2.3%。     

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.