Stripping voltammetric analysis of dicofol on graphene-modified glassy carbon electrode

Ionics - This study is related to the development of a highly sensitive and selective electrode for the electroanalysis of dicofol (DCF) by the modification of a glassy carbon electrode (GCE) with...     

Adiabatic approximation for a bound acoustic deformation potential polaron in a strong magnetic field

On the basis of the usual adiabatic scheme applied to a bound polaron in a strong magnetic field we observe an enhancement of the binding energy due to electron-lattice coupling via the deformation potential. This enhancement, being more pronounced with increasing field intensity, is, however, negligible for most common materials in experimentally interesting magnetic fields.     

Efficient and chemoselective alkyl bromoacetate-Zn mediated transesterification method

Alkyl bromoacetates were shown to be versatile transesterification reagents. Isoxazoles underwent chemoselective transesterification when treated with alkyl bromoacetate-Zn in THF at reflux. A suggested mechanism of the new reaction was discussed.     

Ab initio VB Studies of the Ground and Low-lying Excited States of BeH and BH

A scheme has been proposed to classify valence bond(VB) wave functions for the calculations of ground and excited states,according to the symmetry properties of one-electron orbitals which are involved in the construction of VB wave functions.This scheme is illustrated by the examples of BeH and BH.Ab initio VB computations of these two test molecules in combination with the present classification scheme give reliable results.For example,calculation results show that the state C2∑ of BeH is stable,with the bonding energy 0.87 eV and bond length 0.238nm,which are in good agreement with those obtained by Gerratt et al.The bonding features of ground and low-lying excited states of BeH and BH are discussed.     

硒对不同水体致癌因子诱发健康人微核的拮抗作用

采用微核检测技术，研究了亚硒酸钠对启东肝癌高发区不同类型饮用水诱发健康人外周血淋巴细胞微核的拮抗作用。结果表明：（１）各实验水体对细胞的毒性作用，宅沟水〉泯沟水〉自来水〉双蒸水。微核率随着实验水体剂量的增加而升高；（２）１ｍｇ／Ｌ的亚硒酸钠浓度对泯沟水，自来水诱发的微核效应有是显的抑制和／或拮抗作用，呈现明显的剂量－效应关系，提示肝癌高发区饮用水体中确存在与肝癌发病相关的致畸因子，补硒确有防与治原     

A New Stigmasterol and a New Eremophilenolide from Ligularia dolichobotrys

A new stigmasterol 3β, 7α, 22-trihydoxystigmast-5-ene (1) and a new eremophilenolide 8α-methoxy-6β-angeloyloxyeremophil-7(1 l)-en-8β, 12-olide-14-oic acid (2) were isolated from Ligularia dolichobotrys Diels. Their structures were deduced on the basis of spectral data.     

Spectrophotometric determination of indium(III) with the polymeric chromogenic reagent PV · FPAQ

Summary The polymeric chromogenic reagent PV · FPAQ has been synthesized by condensing 7-(4-formylphenylazo)-8-quinolinol (FPAQ) with poly(vinyl alcohol) (PVA). With indium(III) the reagent forms in weakly acidic media a water-soluble yellow complex, whose absorption maximum is at 445 nm. The molar absorptivity of the complex was found to be 3.16×10⁴ l · mol^–1 · cm^–1 and Sandell's sensitivity 3.6 ng · cm^–2. Beer's law is obeyed over the range 0–30 g of indium(III) per 25 ml of solution. A Spectrophotometric method for the determination of indium has been worked out and applied to synthetic and authentic samples with satisfactory results.

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Spektrophotometrische Bestimmung von Indium(III) mit dem polymeren chromogenen Reagens PV · FPAQ

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Lecture given at the 2nd National Symposium for Inorganic Micro and Trace Analysis, Xi-An, Peoples Republic of China, September 1988 (see [3])     

Synthetic Studies on Coenzyme Q10. Part 2

An improved route to coenzyme Q₁₀ ( 1 ) starting from commercially available coenzyme Q₁ is described. The key steps in this synthesis are the SeO₂‐mediated oxidation of the protected isoprenylhydroquinone 3 into the (E)‐allyl alcohol 5 without the formation of undesired stereoisomer and the one‐pot reductive elimination of the phenylsulfonyl and dibenzyl groups in 7 by using naphthalenyllithium.