281 resultados para IR-193


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改进了桔梗皂苷D的提取、分离及鉴定方法 .首次利用大孔树脂脱糖脱色及薄层硅胶作色谱系介质 ,并首次利用电喷雾质谱对目标化合物进行跟踪分析 ,使高纯度的目标化合物的分离和鉴定工作得以简化

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A polythiophene film was electrochemically deposited on a Pt micro-plate electrode and investigated by cyclic voltammetry and in-situ reflection microscopic FTIR spectroscopy. The FTIR analysis showed that the electropolymerization of thiophene on the Pt surface was affected Lv the surface adsorption processes of thiophene molecules. Two adsorption modes were identified. Two structure models of the polythiophene chain were observed simultaneously. It was proposed that the good conductibility of the polythiophene film was originated from a co-vibratory equilibrium of the link part of model I and model II.

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The reaction of [Cp*IrCl2](2) with dilithium 1,2-orthocarborane-1,2-diselenolate 3 leads to the green 16-electron diselenolene complex [Cp*Ir{Se2C2(B10H10)}] (4) which takes up two-electron ligands such as trimethylphosphane to give the 18-electron diselenolate derivative [Cp*Ir(PMe3)-{Se2C2(B10H10)}] (5). The molecular structures of 4 and 5 were determined by X-ray crystal structure analysis. The Se-77-nuclear shielding in 4 is lower by almost 500 ppm relative to that in 5.

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In this paper, an introduction of wavelet transform and multi-resolution analysis is presented. We describe three data compression methods based on wavelet transform for spectral information,and by using the multi-resolution analysis, we compressed spectral data by Daubechies's compactly supported orthogonal wavelet and orthogonal cubic B-splines wavelet, Using orthogonal cubic B-splines wavelet and coefficients of sharpening signal are set to zero, only very few large coefficients are stored, and a favourable data compression can be achieved.

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用傅立叶变换红外光谱对乙烯基甲醚/交替马来酸酐共聚物多缩乙二醇酯体系(CBP和CBPS单离子体系)和聚氧化乙烯共混物及其盐复合物的结构和相容性进行了研究,对主要红外光谱峰作了归属。结果表明,CBP与PEO、CBP、PEO和LiClO4分子间作用力较弱,易出现相分离,温度变化对CBP/PEO的相容性无影响,只影响PEO的结晶,加入LiClO4抑制了PEO的结晶。在CBPS/PE共混体系中存在着强的离子—偶极相互作用,改善了相容性,得到了热力学相容体系。共混比影响离子—偶极键浓度,对键强影响不大,此外还有弱的偶极—偶极相互作用存在

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The pentamethylcyclopentadienyl iridium complexes Cp*Ir(PMe3)(E-n) (E = S, n = 4, 5 or 6; E = Se, n = 2 or 4 E = Te, n = 2) react with dimethyl acetylenedicarboxylate to give Cp*Ir(PMe3)[E2C2(COOMe)(2)] compounds which tend to lose the trimethylphosphine ligand; the molecular structure of the dithiolene derivative, Cp*Ir[S2C2(COOMe)(2)], has been determined.

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Carbonyl-iridium half-sandwich compounds, Cp*Ir(CO)(EPh)(2) (E = S, Se), were prepared by the photo-induced reaction of Cp*Ir(CO)(2) with the diphenyl dichalcogenides, E2Ph2, and used as neutral chelating ligands in carbonylmetal complexes such as Cp*Ir(CO)(mu-EPh)(2)[Cr(CO)(4)], Cp*Ir(CO)(mu-EPh)(2)[Mo(CO)(4)] and Cp*Ir(CO)(mu-EPh)(2)[Fe(CO)(3)], respectively. A trimethylphosphane - iridium analogue, Cp*Ir(PMe3)(mu-SeMe)(2)[Cr(CO)(4)], was also obtained. The new heterodimetallic complexes were characterized by IR and NMR spectroscopy, and the molecular geometry of Cp*Ir(CO)(mu-SePh)(2)[Mo(CO)(4)] has been determined by a single crystal X-ray structure analysis. According to the long Ir...Mo distance (395.3(1) Angstrom), direct metal-metal interactions appear to be absent. (C) 1998 Elsevier Science S.A. All rights reserved.

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本文通过对铕和铽在Ca5(PO4)3Cl基质中的发光特征的研究,发现铕和铽之间存在着电子转移现象,并对其反应机理进行了探讨。Eu3+(4f6)和Tb3+(4f8)通过电子转移使它们达到电子结构稳定的Eu2+(4f7)和Tb4+(4f7)。在同一基质中双掺铕和铽时,在254nm紫外光激发下,能同时观察到Eu2+,Eu3+和Tb3+的发射,这一现象的发现为单基双掺希土三基色荧光粉的研制提供了理论依据。

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通过中空纤维膜逆流萃取,研究了伯胺N1923对Th4+和RE3+的萃取分离过程。测定了水相料液硫酸浓度、水相与油相流量对传质系数的影响,并对包头矿硫酸分解浸出液进行中空纤维膜萃取实验。结果表明,Th4+的传质系数受水相流量影响,与酸度及油相流量无关,总传质速率受水相临界层传质步骤控制。RE3+的传质系数不受水相流量影响,油相流量影响很小,但受硫酸浓度的影响,总传质速率受萃取反应速率控制。根据传质速率的不同,对包头矿硫酸浸出液进行萃取分离,在8h内Th4+可基本萃取完全,而RE3+及Fe3+基本不被萃取,故可在密封条件下分离钍。

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本文对稀土光、电、磁等功能材料的发展作了评述,并就我国开展稀土功能材料及有关基础问题的研究提出了建议.

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Abnormal IR spectra of CO adsorbed at the surface of glass carbon electrode modified with polypyrrole film with Pt microparticles are reported.

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用循环伏安法和恒电流电解后的电位时间曲线法,研究了LiClKCl熔体中Nd3+和Ho3+在Mo电极上的电化学行为。结果表明,Nd3+和Ho3+在Mo电极上的还原都为一步3电子可逆过程。其扩散系数分别为:113×10-6和2142×10-5cm2·s-1(450℃),450℃下Ho3+/Ho电极对的标准氧化还原电位为2987V(vs·Cl/Cl-1),并讨论了实验值较理论值偏负的原因。

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A new immobilization material and an immobilization method for a glucose sensor with HEFc (hydroxyethylferrocene) as mediator is described. In the course of three months, the enzyme electrode shows almost no deterioration in its response characteristics. The response time is less than 30 s. The electrode has a wide linear range up to 10 mmol l(-1) with good repeatability. The kinetic parameters have also been calculated.

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Twelve mediators have been modified by adsorption onto the paraffin impregnated graphite electrodes (IGE). The resulting electrodes exhibit electrocatalytic activity of different degrees towards oxidation of 1,4-dihydronicotinamide adenine dinucleotide (NADH). The electrocatalytic ability of the chemically modified electrode (CME) depends mainly on the formal potential and molecular structure of mediator. The formation of the charge transfer complex between NADH and adsorbed mediator has been demonstrated by the experiments using a rotating disk electrode. An electrocatalytic scheme obeying Michaelis-Menten kinetics has been confirmed, and some kinetic parameters were estimated. The solution pH influences markedly the electrocatalytic activity of the modified electrode. Various possible reasons are discussed.

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本文通过对不同条件下的Co(W_2O_7)_6~(10-)和CuW_(12)O_(40)~(6-)掺杂聚吡膜ESR谱线的分析并以相同条件下NO_3~-掺杂聚吡咯膜作为参照,表明杂聚阴离子不仅起着中和电性的作用,而且与聚吡咯分子链相作用形成某种加合物,它影响聚吡咯的电结构,这种加合物在过正或过负的电位下均不稳定.首次发现在CuW_(12)O_(40)~(6-)掺杂的干态聚吡咯膜具有Dysonian线型,表明膜中其它电结构的存在.