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茶叶多糖及其铈配合物对质粒DNA及有机磷农药的降解作用 总被引:19,自引:0,他引:19
以茶叶多糖(TPS)为配体与四价的铈(Ce^4 )结合,形成了水溶性的茶叶多糖铈配合物(Ce-TPS)。在中性条件下,TPS及Ce-TPS对质粒DNA(Pllasmid DNA)有一定的裂解作用,对有机磷农药毒死蜱有很强的降解作用。将TPS及Ce-TPS应用于大田,可有效降低菠菜中毒死蜱及乐果残留量,比对照低5倍以上,其中Ce-TPS处理8d后毒死蜱及乐果残留量均低于国家标准(≤1.0mg.kg^-1)。 相似文献
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铈(Ⅲ),铈(Ⅳ)与植酸生成的固态配合物的研究 总被引:1,自引:0,他引:1
铈(Ⅲ)、铈(Ⅳ)与植酸生成的固态配合物的研究黎晓霞杨瑛*刘建民杨汝栋(兰州大学化学系兰州730000)关键词铈(Ⅲ),铈(Ⅳ),植酸,固态配合物1996-11-20收稿,1997-05-26修回植酸(H12IHP)作为沉淀剂已被用于Th4+的定量测... 相似文献
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铈(Ⅲ)-氨基酸-咪唑三元配合物的表征和循环伏安行为研究 总被引:7,自引:0,他引:7
合成了铈(Ⅲ)-色氨酸-咪唑和铈(Ⅲ)-苯丙氨酸-咪唑三元配合物,对配合物进行了元素分析、摩尔电导测试、热重-差热分析及红外光谱分析,确定了配合物的组成和成键特征,并用循环伏安法研究了铈(Ⅲ)离子、铈(Ⅲ)与氨基酸及咪唑混合溶液、铈(Ⅲ)二元及三元配合物在玻碳电极上的电化学行为。实验结果表明,在-0.10~1.10V(vs.SCE)电位扫描范围内,两种铈(Ⅲ)三元配合物显示了安全不可逆的电子迁移过 相似文献
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研究了稀土元素铈(Ⅲ)离子与3,4-二羟基苯甲酸(H3L)在水溶液体系中生成羧基配位化合物的条件,表征其组成为Ce(H2L)2(OH).3H2O。并研究了该配合物在一定条件下,铈离子由羧基配位反应变由为两个邻酚羟基配位的配合物(Ce(HL)n的转型反应及氧化物铈(VI)配合物的反应。 相似文献
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钛铁试剂分光光度法直接测定轻稀土中的铈 总被引:2,自引:0,他引:2
利用铈的变价以及Ce(Ⅳ)-Tiron配合物在不同酸度条件颜色的特殊性,建立了无需预先分离而直接测定混合稀土中铈含量的分光光度法,在PH为9.0条件下,借助空气的氧化,Ce(Ⅲ)和Ce(Ⅳ)都与Tiron形成Ce(Ⅳ)-Tiron配合物。该配合物在PH为5.0时呈亮黄色,在435nm处有最大吸收。 相似文献
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本文设计合成了两个含有联噻唑的钌(Ⅱ)配合物[Ru(btz)3](CIO4)2(1)和[Ru(btz)(dppz)2](c104)2(2)(btz=4,4’bithiazole,dppz:dipyrido[3,2-a:2’,3’c]phenazine).通过元素分析、ES-MS、1HNMR和X射线单晶衍射表征了配合物的结构.运用光谱滴定和黏度实验研究了配合物与DNA的作用,发现配合物1与DNA以静电方式结合,配合物2以插入模式与DNA结合.凝胶电泳实验表明配合物1和2在光照射下均可有效断裂DNA,单线杰氢(1O2)和脊某自由墓(OH、县推动断裂反应的活性物种. 相似文献
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以一种1,4,7,10,13,16,19,22,25,28,31-十一氮杂2,5,8,11,14,17,20,23,26,29,32-十一酰基-环三十三烷的衍生物(CYC)为配体,在溶液中和Ce(Ⅲ,M)离子形成氮杂大环铈配合物(M-CYC)作为仿生催化剂,通过紫外光谱法、荧光光谱法和凝胶电泳法研究了M-CYC配合物与DNA的相互作用. 结果表明,M-CYC与小牛胸腺DNA(CT DNA)以嵌插方式相互作用,在pH = 8.16的缓冲体系中,其结合常数Kb = 2.0×104 L/mol. 凝胶电泳结果表明,当自由基捕捉剂存在时,M-CYC可将超螺旋pUC19 DNA切割为缺刻型DNA,其切割方式为水解切割. 相似文献
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邻香草醛缩牛磺酸Schiff碱铕(Ⅲ)配合物与DNA的插入作用 总被引:1,自引:0,他引:1
合成了3种铕(Ⅲ)与邻香草醛缩牛磺酸Schiff碱配合物[EuTOvL(NO3)]·2H2O(TOy:Schiff碱配体,L^1:1,10-邻菲咯啉,L^2:2,2'-联吡啶,L^3:2-氨基吡啶),并对其进行了结构表征;采用荧光光谱法和黏度法研究了配合物与DNA的相互作用模式.实验结果表明3种配合物对DNA均有不同强度的插入作用,其插入能力在一定范围内与配合物的浓度正相关,且与配合物分子适宜的平面性有关,3种配合物对DNA插入能力顺序为:[EuTOvL^1(NO3)]·2H2O〉[EuTOvL^2(NO3)]·2H2O〉[EuTOvL^3(NO3)]·2H2O. 相似文献
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The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted
indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator
model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was
established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing
analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997. 相似文献
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Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared. 相似文献
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Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position. 相似文献
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Stepkowska E. T. Perez-Rodriguez J. L. Jimenez de Haro M. C. Sayagues M. J. 《Journal of Thermal Analysis and Calorimetry》2002,69(1):187-204
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
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The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations
were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples
were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of
hematite Fe2O3. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the
best fitting experimental data.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6. 相似文献
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