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用自行安装的精密静弹燃烧量热计测定了四苯基卟啉(TPP)、四甲苯基卟啉(T_((PCH)_3)PP)、四对甲氧苯基卟啉(T_((P-OCH)_3)PP)和四邻氨苯基卟啉(T_((O-NH)_2)PP)的标准燃烧能,并计算出标准生成焓。样品 1.将苯甲醛加入沸腾的丙酸中迥流30分钟后冷至50~60℃,加入乙醇,冷却,过滤,紫色产物用甲醇洗,干燥后得TPP粗品。将粗品溶于迥流的二氯甲烷,加入溶于苯的DDQ迥流30分钟,蒸除溶剂,残渣溶于氯仿,氧化铝-氯仿柱层析,氯仿-甲醇重结晶制得纯TPP. 相似文献
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LI Zhong WANG Hongjuan XI Hongxia XU Kefeng WEN Jun Research Institute of Chemical Engineering South China University of Technology Guangzhou 《Chinese Journal of Reactive Polymers》2001,(2)
1. INTRODUCTION In some cities of China, cancer and breath system diseases caused by the pollution of volatile organic compounds (VOCs) have been obviously increasing. The VOCs includes BTEX (benzene, toluene, ethylbenzene, and xylene), aldehydes, cresol, phenol, acetic acid, polynuclear aromatic hydrocarbons (PAHs), which have long-term human health implications. Emission of the VOCs has threatened the health of people seriously [1,2]. The pollution of the VOCs mostly hails from… 相似文献
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以甲基苯基聚硅烷 (PhSiMe ) n为原料 ,在无水AlCl3 存在下 ,通过与酰氯、酸酐及酯的取代反应合成了氯代聚硅烷及一系列共聚物 .在乙酰氯的作用下 , (PhSiMe ) n上的苯基能够被近乎完全的取代而生成氯代聚硅烷 .一元酸酐 (乙酸酐和丙酸酐 )在用酰氧基部分取代聚硅烷上苯基的同时 ,进行得更多的还是Cl取代 .而顺丁烯二酸酐、邻苯二甲酸酐和乙酸乙酯则只进行不完全的Cl取代 ,根据分子活性的不同得到取代比率各不相同的共聚物 .初步分析了各反应的过程 ,讨论了影响反应的因素 ,同时对于各产物的荧光和紫外特性也进行了分析和讨论 相似文献
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Abstract— The μs transient absorption spectra of benzene solutions of 7- cis , 7,9- dicis , 11- cis and all- trans isomers of retinal were recorded both by direct and sensitized excitation. The spectra are indistinguishable, as are the transient decay rates. The results are consistent with the notion of rapid isomerization of the 7- cis triplets and possibly equilibration of all retinal triplets. 相似文献
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In this paper, six kinds of activated carbons such as Ag+-activated carbon, Cu2+-activated carbon, Fe3+- activated carbon, activated carbon, Ba2+- activated carbon and Ca2+-activated carbon were prepared. The model for estimating activated energy of desorption was established. Temperature-programmed desorption (TPD) experiments were conducted to measure the TPD curves of n-hexanol and then estimate the activation energy for desorption of n-hexanol on the activated carbons. Results showed that the activation energy for the desorption of n-hexanol on the Ag+- activated carbon, the Cu2+- activated carbon and the Fe3+- activated carbon were higher than those of n-hexanol on the activated carbon, the Ca2+- activated carbon and the Ba2+- activated carbon. 相似文献
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热塑性塑料熔体质量流动速率测量不确定度的评定 总被引:1,自引:0,他引:1
以聚乙烯为例讨论了热塑性塑料熔体质量流动速率测量不确定度的来源,依据JJF 1059-1999对熔体流动速率测试过程中的测量不确定度分量进行了分析和评定。7149型聚乙烯熔体质量流动速率测量结果的扩展不确定度为0.096 g/(10 m in)。 相似文献
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自从发现烷氧基钾(ROK)/烷基锂(RLi)双金属引发体系对丁二烯苯乙烯阴离子共聚具有高效竟聚率调节作用以来[1],相关的机理研究一直十分活跃[2~6].在这类双金属引发体系中,由于含有K、Li两种反离子,因此可能存在钾活性种(PK)和锂活性种(PLi)的交互缔合体.但迄今有关不同反离子活性种形成交互缔合体的研究报道较少.本工作利用2甲基2己醇钾对苯乙烯均聚反应速度具有较大影响这一特性,对低K/Li情况下可溶性醇钾/nBuLi双金属引发体系苯乙烯均聚动力学进行了研究.建立了以交互缔合体为基础的反应动力学模型.求得了PK的增… 相似文献
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循环伏安法的电扫描方式对苯胺聚合产物形貌影响的观察 总被引:1,自引:0,他引:1
在含有0.2 mol.L-1苯胺的0.5 mol.L-1H2SO4溶液中,以扫描速度50 mV.s-1,扫描电位为-0.1~0.9 V,采用循环伏安法(CV),在金属Ti基体上,通过控制扫描方式分别得到了颗粒状、纤维状及管-片状的苯胺聚合产物,分析了形成不同形貌聚苯胺的原因,并通过扫描电子显微镜(SEM)、循环伏安法和电化学阻抗谱(EIS)对不同形貌聚苯胺的结构和性能进行了表征.结果表明,不同形貌聚苯胺的形成是由于聚苯胺的成核及生长模式不同,而无论何种形貌的聚苯胺膜都具有很大的比表面积和良好的导电性能,其中,管-片状聚苯胺的膜层阻抗最小,导电性能最好. 相似文献
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固相萃取-高效液相色谱同时测定大米中的4种烟碱农药残留量 总被引:3,自引:0,他引:3
建立了高效液相色谱法同时测定大米样品中呋虫胺、噻虫胺、吡虫啉、吡虫清4种烟碱农药残留量的检测方法,对4种烟碱农药在ENVI-Florisil和Carb复合固相萃取柱上的保留行为进行了研究。样品用乙腈提取,固相萃取净化,HPLC-DAD分离检测,外标法定量。峰面积与标准溶液浓度在0.1~1.0 mg/L范围内呈良好的线性关系,相关系数大于0.9996。样品加标回收率为75.5%~96.0%,相对标准偏差为0.49%~4.36%(n=6),检出限达到0.004 mg/kg。 相似文献
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Witold Przychodzeń 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1621-1633
Reaction of the Lawesson's reagent (LR) with aliphatic 1,2- and 1,3-diols as well as with aromatic 2,2′-dihydroxybiphenyl led to new products. Stable di-tert-butylammonium salts of bis-anisyldithiophosphonic acids 6 were isolated and were then converted into unique 9-, 9-, and 10-membered cyclic disulfides 7 and into S,S-dimethyl esters 8. The salts of bis-anisyldithiophosphonic acids 6 were shown to be capable of splitting the disulfide bond of Ellman's reagent. 相似文献
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硅橡胶热降解动力学的研究 总被引:5,自引:1,他引:5
用恒温热失重方法,研究了甲基硅橡胶(Si—O—1),用氢氧化钾催化聚合的甲基硅橡胶(Si—O—2),主链含环二硅氮烷的硅氮橡胶(Si—N—1)以及它与Si—O—1的共混物Si—O—3和与Si—O—2的共混物Si—O—4的热降解反应动力学.结果表明Si—N—1有最高的热稳定性,在氮气下,其降解反应活化能为344kJ/mol.并且发现它分别与Si—O—1和Si—O—2的共混物的热稳定性大幅度提高.Si—O—3在氮气下的降解活化能由未加入Si—N—1前的152kJ/mol提高到230kJ/mol;Si─O─4则由未混入Si─N─1前的61kJ/mol提高到144kJ/mol.我们认为这种作用机理是由于硅氮橡胶除去了微量吸附水和硅羟基并导致催化剂的离子对难于分离的结果. 相似文献
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WALTER H. WADDELL † JULIETTE LECOMTE JOHN L. WEST USAMA E. YOUNES 《Photochemistry and photobiology》1984,39(2):213-219
Abstract— Rhodopsin, the isomeric pigments formed from 9- cis - and 9, 13- dicis -retinal, and the synthetic pigments formed from 9- cis - and 11- cis -14-methylretinal were irradiated with 490 nm light at -196C. Absorption spectral changes indicate that a distinguishable bathorhodopsin type intermediate may be formed for each pigment. The bathorhodopsin intermediates of the 9- cis pigments have band maxima hypsochromically shifted by4–5 nm compared to their corresponding rhodopsins. The bathorhodopsin type intermediate formed upon irradiation of 9, 13- dicis -rhodopsin has an absorption that maximizes 6 nm shorter than that of rhodopsin. Band maxima of the bathorhodopsin intermediates of the 14-methylrhodopsins are bathochromatically shifted ca. 8 nm compared to their corresponding rhodopsins. 相似文献
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