冠醚铕镧异核配合物的合成表征及荧光性质

以 18冠 6为配体 ,分别与高氯酸铕和高氯酸镧在乙腈介质中反应 ,合成冠醚铕和冠醚镧配合物 ;两种冠醚配合物与交联配体———对苯二甲酸反应 ,形成了对苯二甲酸冠醚铕镧异核稀土超分子配合物。由元素分析数据推测 ,超分子配合物的组成式为EuLaL2 L′(ClO4) 4 ·6H2 　 [L =18 C 6 ,L′ =p C6H4(COO-) 2 ],测定了超分子配合物的红外光谱 ,紫外光谱 ,摩尔电导及荧光光谱。结果表明 ,冠醚和对苯二甲酸根与稀土离子配位 ,而高氯酸根离子处于配合物的外界 ,铕镧异核稀土超分子配合物的荧光强度是冠醚铕的 8倍多。     

四磺酸基酞菁钴与硫化物的轴向配位反应研究

文章提出了一种多波长、双系数解析配合物吸收光谱测定配合物组成和稳定常数的方法 ,并用分光光度法对四磺酸基酞菁钴 (CoTsPc)与硫化物的轴向配位反应进行了研究 ,发现该反应与介质 pH值有关。pH =7 0时 ,Co(Ⅱ )TsPc与HS- 反应生成五配位的轴向配合物Co(Ⅱ )TsPc(HS) ,研究了Co(Ⅱ )TsPc与HS- 反应生成Co(Ⅱ )TsPc(HS)的反应热力学 ,计算了不同温度下的反应平衡常数、ΔH 和ΔS ;pH =13时 ,两者发生氧化还原反应 ,生成SCo(Ⅰ )TsPc。     

四水顺丁烯二酸镍配合物的光谱研究

四水顺丁烯二酸镍配合物晶体是由苹果酸和碳酸镍反应制得的。在这一体系中，加热时苹果酸转化为马来酸并与镍离子络合物成标题配合物。本文测定了该配合物的电子吸收光谱和光声光谱，并用配位场理论定地解释了其光谱性质，得到了配合物的晶场参数及中心离子的轨道能级。理论结果与实验结果的互洽表明了配合物晶体结构与电子结构的一致。     

铕、铽-2-噻吩甲酸-2,2''''-联吡啶配合物的合成、表征及荧光性质研究

合成了铕、铽-2-噻吩甲酸的二元配合物和铕、铽-2-噻吩甲酸-2,2'-联吡啶的三元配合物,并对它们进行了元素分析、稀土络合滴定、摩尔电导测定,确定了配合物组成分别为REL3·2H2O及REL3 L'·C2H5OH(RE=Eu,Tb;L=2-噻吩甲酸、L'=2,2'-联吡啶),测定了配体及配合物的IR谱、1H NMR谱及荧光光谱.IR谱和1H NMR谱测定表明,配体2-噻吩甲酸羧基氧、配体邻菲咯啉2个氮原子与稀土离子配位.荧光光谱实验表明,高氯酸铕和高氯酸铽分别与2,2'-联吡啶和2-噻吩甲酸反应形成的三元配合物的荧光明显强于二元配合物.     

铕、铽-2-噻吩甲酸-2,2′-联吡啶配合物的合成、表征及荧光性质研究

合成了铕、铽-2-噻吩甲酸的二元配合物和铕、铽-2-噻吩甲酸-2,2′-联吡啶的三元配合物,并对它们进行了元素分析、稀土络合滴定、摩尔电导测定,确定了配合物组成分别为REL₃·2H₂O及REL₃ L′·C₂H₅OH(RE=Eu,Tb; L=2-噻吩甲酸、L′=2,2′-联吡啶), 测定了配体及配合物的IR谱、1H NMR谱及荧光光谱。IR谱和1H NMR谱测定表明,配体2-噻吩甲酸羧基氧、配体邻菲咯啉2个氮原子与稀土离子配位。荧光光谱实验表明,高氯酸铕和高氯酸铽分别与2,2′-联吡啶和2-噻吩甲酸反应形成的三元配合物的荧光明显强于二元配合物。     

荧光光谱法研究姜黄素铕配合物与牛血清蛋白的相互作用

用光谱法研究了姜黄素铕配合物与牛血清白蛋白的作用机理.在298,304,308K和310K时,用荧光光谱测定配合物与牛血清白蛋白的结合常数,由结合反应的焓变和熵变推测范德华力和氢键是主要内在结合力;依据Forster能量转移理论计算结合距离为2.1nm;同步荧光光谱确定配合物对牛血清白蛋白结构有影响.     

卟啉配合物-巯基棉体系分光光度法测定中药中铅、镉、铜

研究了卟啉与铅、镉、铜的反应及配合物的电子吸收光谱。结合巯基棉分离富集方法 ,将此金属卟啉配合物体系成功地应用于中药中微量铅、镉、铜的测定。方法简便 ,测定体系抗干扰的效果好 ,灵敏度高。实际样品测定的RSD在 3 3%～ 9 6 %之间。样品加标回收率在 90 %～ 1 0 3%之间。     

黄酮配合物抗自由基活性的亚甲基蓝光谱测定体系的研究

亚甲基蓝(MB)可捕获Fenton反应产生的羟自由基生成无色加合物,选用亚甲基蓝为槲皮素(Que)及其配合物抗羟自由基活性测定体系的指示剂。实验优化测试条件为：体系pH 8.0,加入H₂O₂溶液(0.3%) 0.50 mL,FeSO₄溶液(5 mmol·L-1) 0.50 mL和MB溶液(2.56×10-5 mol·L-1)1.0 mL。由此建立了测定槲皮素配合物抗·OH活性的光谱测定方法。方法简便,尤其适合于配合物体系抗自由基活性的分析。测定了槲皮素及Que-Zn(Ⅱ),Que-Cu(Ⅱ),Que-Fe(Ⅲ)配合物的抗·OH活性。结果表明3种槲皮素配合物的抗羟自由基活性均比槲皮素高,配合物活性Que-Cu(Ⅱ) ＞Que-Zn(Ⅱ)＞Que-Fe(Ⅲ),表现出金属离子与有机活性配体协同作用可提高其抗氧化活性的能力。     

糠醛缩壳寡糖席夫碱及Cu(Ⅱ)配合物与DNA之间的作用机制

以糠醛和壳寡糖反应生成的席夫碱,与不同摩尔比的Cu2+配位合成配合物FCOS-Cu11、FCOS-Cu13和FCOS-Cu31,并研究配合物与DNA之间的作用机制。采用循环伏安、紫外-可见吸收光谱、粘度和DNA熔点测定的方法,分别研究了席夫碱及配合物与DNA之间的作用机制。合成的3种配合物具有电化学活性。加入DNA后,配合物的氧化峰电流减小,峰电位微弱移动。配合物的吸收峰强度减色显著,同时伴有峰位红移现象。配合物加入后,DNA的相对粘度和熔点呈增大趋势。结果表明,席夫碱及配合物与DNA之间存在嵌插结合,且3种配合物中的Cu2+含量与DNA的嵌插作用强度有关,结合强度依次为FCOS-Cu11FCOS-Cu13FCOS-Cu31。     

邻氨基苯甲酸2,2′-联吡啶铕镧混合稀土配合物的红外及荧光研究

用邻氨基苯甲酸和２,２′－联吡啶与氯化铕和氯化镧在溶液中反应,合成了混合混合稀土配合物,测定了配合物的红外光谱及荧光光谱,结果表明,稀土离子均与配体形成配合物,在３４３ｎｍ紫外光激发下,在一定范围内,用不发光的Ｌａ＾３＋离子取代邻氨基苯甲酸－２,２′联吡啶铕配合物中的Ｅｕ＾３＋离子,可以提高Ｅｕ＾３＋离子的特征发光强度,而对发射峰位影响不大,本文对发光机理进行了初探。     

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.