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991.
Neutral and non-doped poly(3,4-ethylenedioxythiophene), PEDOTh(Ni), and its hexyl derivative, PEDOTh-C6(Ni), have been prepared by organometallic dehalogenation polycondensation of 2,5-dichloro-3,4-ethylenedioxythiophene and its hexyl derivative with a zerovalent nickel complex. PEDOTh-C6(Ni) was soluble in organic solvents and 1H NMR data indicated that it had an Mn of 11,000. MALDI-TOF mass analysis of PEDOTh(Ni) gave Mn and Mw of about 1700 and 2400, respectively. PEDOTh-C6(Ni) showed a UV-Vis absorption peak at 546 nm in CHCl3. Electrochemical oxidation of PEDOTh-C6(Ni) started at about −0.40 V vs Ag+/Ag and gave a peak at 0.20 V vs Ag+/Ag. Chemical and electrochemical oxidation (or p-doping) of PEDOTh-C6(Ni), both in solutions and in a solid state, led to weakening of the original π-π peaks and rise of new peak(s) in a region of 800-1500 nm. The p-doping of PEDOTh-C6(Ni) caused not only a decrease in the intensity of 1H NMR signals of the bridging ethylene hydrogens but also a decrease in that of the hexyl side chain, suggesting a strong interaction of the p-dopant with the side chain. NMR data of poly(3-methoxythiophene-2,5-diyl) also supported an assumption that p-doping brings about a severe change in electronic state of the substituent attached to the polythiophene main chain. PEDOTh(Ni) had a density of 1.71 g cm−3; the molecular packing mode of PEDOTh(Ni) is discussed based on the density of the polymer and its XRD data.  相似文献   
992.
8-R-9苄基-9H-嘌呤衍生物的合成研究   总被引:5,自引:2,他引:3  
刘福胜  杨锦宗 《精细化工》2002,19(4):189-192
采用 (Ph3 P) 2 PdCl2 为催化剂 ,DMF为溶剂 ,对 8 碘 9 苄基 9H 嘌呤与有机锡试剂RSnBu3 (R=乙烯基、2 噻吩基、2 呋喃基、苯乙炔基和苯基等 )之间的Stille偶合反应进行了研究 ,合成出了5种 8位取代的嘌呤衍生物。在反应温度为 80℃ ,n(8 碘 9 苄基 9H 嘌呤 )∶n (RSnBu3 )∶n〔(Ph3 P) 2 PdCl2 〕 =1 0∶1 2∶0 0 5的较佳工艺条件下 ,产品收率 4 1%~ 91%。用1H NMR、13 C NMR和MS对产物进行了表征  相似文献   
993.
Laguerre Functional Model has many advantages such as good approximation capability for the variances of system time‐delay, order and other structural parameters, low computational complexity, and the facility of online parameter identification, etc., so this model is suitable for complex industrial process control. A series of successful applications have been gained in linear and non‐linear predictive control fields by the control algorithm based on Laguerre Functional Model, however, former researchers have not systemically brought forward the theoretical analyses of the stability, robustness, and steady‐state performance of this algorithm, which are the keys to guarantee the feasibility of the control algorithm fundamentally. Aimed at this problem, we introduce the principles of the Incremental Mode Linear Laguerre Predictive Control (IMLLPC) algorithm, and then systemically propose the theoretical analyses and proofs of the stability and robustness of the algorithm, in addition, we also put forward the steady‐state performance analysis. At last, the control performances of this algorithm on two different physical industrial plants are presented in detail, and a number of experimental results validate the feasibility and superiority of IMLLPC algorithm. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   
994.
995.
本文叙述了实验狗经氡子体暴露后血、毛中~(210)Po、~(210)Pb 含量、~(210)po/~(210)Pb 比率及血中~(210)Po,~(210)Pb 排出的动态变化。  相似文献   
996.
A new method of characterization for stratified thermal energy stores   总被引:1,自引:0,他引:1  
A new method for characterization of stratified thermal energy stores (TES) that integrates both the first law and the second law concerns is presented here. The first law concern is incorporated into a quantity called energy response factor and the second law concern into an entropy generation ratio. A product of these two quantities is at the heart of the TES efficiency definitions. This approach removes the overemphasis of the existing methods either on the first or the second law of thermodynamics which often biases the characterization results. The information about the evolution of the temperature field of the system in time is the prerequisite of the new method. It may be obtained from experiments or from suitable numerical simulations. The current method can be easily integrated into computational fluid dynamic (CFD) simulations and thus facilitate CFD-based design analysis. As an example of such CFD-integrated analysis, a large-scale hot water seasonal heat store is numerically studied to identify the effects of aspect ratio, containment shape, internal structures, and containment size on their efficiency. The results suggest the effectiveness of the new method in deriving useful design insights.  相似文献   
997.
o-Dihydroxyphenoloxidase (E.C. 1.14.18.1) (o-DPOase) was extracted from acetone-extracted freeze-dried yam tubers, and fractionated by (NH4)2SO4 precipitation and chromatography on DEAE-cellulose to give two forms from Dioscorea alta L. (cv. UM680) and three forms from D. rotundata Poir. (cv. Nwopoke). Polyacrylamide gel electrophoresis revealed one of the forms from each species to contain two protein bands with o-DPOase activity. o-DPOase from D. alata showed activity with catechol, (+)-catechin, (?)-epicatechin and chlorogenic acid, but not with tyrosine, as substrate, o-DPOase from D. rotundata showed activity only with catechol and (+)-catechin. Km values for D. rotundata enzymes, calculated assuming a two-substrate reaction, were between 0.2 and 0.8 mM for oxygen and 70 and 120 mM for catechol. The enzyme was most active between pH 5.5 and pH 7.0, and showed slight activation after holding for 2 minutes at 40 or 50°C. After heating to above 60°C the enzyme showed evidence of irreversible denaturation. Theo-DPOase activity extracted from ten cultivars of five species of D. alata L., D. bulbifera L., D. cayenensis Lam., D. dumetorum Pax, and D. rotundata Poir. were compared.  相似文献   
998.
本文首先讨论GPS星座组成及美国的用政策,阐述了AS措施及其对GPS测量的影响。然后,对抗AS的若干方案进行介绍,分别对平方法、互相关法、码相关干法及P-W技术(Ashtech法)进行叙述和评论,指出它们的优缺点,评述它们在GPS技术发展过程所起的作用。最后,对GPS星座建成后的形势作了小结,并对当前我国GPS事业的有关问题提出四点建议。  相似文献   
999.
多孔硅发光机制的分析   总被引:4,自引:0,他引:4  
从量子力学的基本理论出发讨论了量子限制效应,推导出多孔硅有效禁带宽度增量并用量子限制效应和表面态及其物质在发光中作用的理论解释了PS光致发光的实验现象。  相似文献   
1000.
本研究采用电子通道技术(ECP)对单晶和双晶外延生长的YBa_2Cu_3O_7(YBCO)超导薄膜的结构、取向和表面完好性作检测,并证实对衬底的预处理可改善外延超导薄膜的质量;还对YBCO/CeO_2/MgO/SrTiO3的双外延薄膜作研究。  相似文献   
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