共查询到20条相似文献,搜索用时 15 毫秒
1.
Bingcheng Yang Feifang Zhang Xinmiao Liang 《Central European Journal of Chemistry》2012,10(3):472-479
This review summarizes the development of capillary ion chromatography (CIC) over approximately the last 5 years. It mainly
focuses on the technologic aspects of several key components associated with CIC, including micropump, microscale electrodialytic
eluent generator, microscale suppressor and the detector.
相似文献
2.
Fluorescence spectroscopy and circular dichroism (CD) spectroscopy were used to investigate the interaction of coumarin-3-carboxylic
acid with human serum albumin (HSA) and bovine serum albumin (BSA) under physiological conditions in a buffer solution of
pH 7.4.
相似文献
3.
Mi?osz Mi?tkiewski Beata Powa?a Bartosz Staniszewski Maciej Kubicki W?odzimierz Urbaniak Cezary Pietraszuk 《Central European Journal of Chemistry》2011,9(4):728-736
Selected β-diketones bearing unsaturated derivatives have been demonstrated to undergo homo-metathesis and cross-metathesis with selected
olefins in the presence of Grubbs catalysts. The reactions led to respective homo- and cross-metathesis products mainly with
good yields and selectivities.
相似文献
4.
Thermodynamics and kinetics of adsorption of congo red (CR) on cellulose are studied at 308–328 K. In the used concentration
range of CR, interaction of CR with cellulose is exothermic and CR molecules adsorb chemically on cellulose surface. The effects
of contact time, temperature and initial concentration of CR on kinetics of its adsorption on cellulose were investigated.
The process proceeds according to the pseudo-second-order equation. Initial adsorption rate of adsorption is first-order in
CR and the intraparticle diffusion of CR molecules within cellulose is identified as the main rate-limiting step.
相似文献
5.
This article describes the simple hydrodehalogenation of halogenated anilines and their derivatives by the action of Raney
aluminium-nickel alloy in aqueous alkaline solution at room temperature. The reaction course was monitored by means of 1H
nuclear magnetic resonance (NMR) spectroscopy and GC-MS spectra.
相似文献
6.
Mažvydas Mackevičius Feliksas Ivanauskas Aivaras Kareiva 《Central European Journal of Chemistry》2012,10(2):380-385
In our work, we present a method for estimation of the diffusion and reaction rates of synthesis at high temperatures using
limited information from laboratory experiments, such as synthesis time and dimensions of reactants. Synthesis by sol-gel
and solid-state reactions is considered. The inverse modeling problem is solved for one- and two-dimensional models. Explicit
formulas for the diffusion coefficient and reaction rate as functions of temperature are obtained. The activation energies
are calculated, and the lower bounds of diffusion and reaction rates are estimated, thus obtaining conditions for occurrence
of synthesis.
相似文献
7.
Cory C. Pye 《Central European Journal of Chemistry》2011,9(4):567-571
A geometry and SCF convergence study of Hartree-Fock calculations using the 6-31G* basis set is carried out on the set of
all possible diatomic molecules formed from atoms with Z≤36. The utility of Hartree-Fock calculations using the smaller STO-3G
basis set to improve the convergence behavior is demonstrated.
相似文献
8.
Zofia Lendzion-Bieluń 《Central European Journal of Chemistry》2012,10(2):327-331
Based on the active surface model of the iron catalyst for ammonia synthesis, the assumptions which led to obtaining the cobalt
catalyst for ammonia synthesis were described. The incorporation into the system small amounts of manganese, an element which
binds oxygen stronger than cobalt, has influence the development of the catalyst’s specific surface area. The activity of
manganese modified catalysts is higher than that of cobalt catalyst without manganese addition. The obtained catalysts were
characterized with the following methods: ICP-OES, XRD, BET
相似文献
9.
10.
The oxidative catalytic degradation of the cationic dye methylene blue (MB) with NaOCl in aqueous solutions was studied using
individual and iron modified Ni- and Co-oxide systems as catalysts. The adsorption extent and the contribution of the uncatalyzed
oxidation on the overall degree of MB were determined. The results indicate that methylene blue—a representative of a class
of dyestuffs resistant to biodegradation—could be successfully decolorized and degraded using nickel and cobalt oxide catalysts
at room temperature. The highest catalytic activity manifests in the Co-oxide system which is consistent with the adsorption
data. The oxidative degradation reaction proceeds via first-order kinetics. Temperature has a relatively small effect on the
methylene blue degradation kinetics. The results obtained reveal that the catalysts investigated are suitable for oxidative
destruction of methytlene blue dye in wastewaters.
相似文献
11.
Rūta Araminaitė Rasa Garjonytė Albertas Malinauskas 《Central European Journal of Chemistry》2008,6(2):175-179
Kinetic study on the decomposition of Prussian Blue electrocatalytic layer during electrochemical reduction of hydrogen peroxide
has been studied in relation to biosensor application of this electrocatalyst. The decomposition has been shown to proceed
as a nearly exponential decay process and the corresponding first-order rate coefficients were determined. It has been shown
that the decomposition proceeds about 10 times faster in pH 7.3 buffer solution as compared to pH 5.5 buffer. A linear dependence
of the decomposition rate on the concentration of hydrogen peroxide has been found.
相似文献
12.
Anuţa Câmpean Mihaela Tertiş Robert Săndulescu 《Central European Journal of Chemistry》2011,9(4):688-700
Electrochemical behaviour of some alkaloids, namely: caffeine, aminophylline, theophylline, codeine phosphate and papaverine
hydrochloride, that are in solution in various combinations or in the presence of other compounds contained in pharmaceuticals
or in real samples (urine) was investigated using cyclic voltammetry (CV), square-wave voltammetry (SWV) and differential
pulse voltammetry (DPV) on electrochemically activated glassy carbon electrode.
相似文献
13.
Irena Baranowska Sylwia Magiera Jacek Baranowski 《Central European Journal of Chemistry》2011,9(6):972-981
The aim of this paper is to optimize and validate a high performance liquid chromatography (HPLC) method for separation and
quantification of five isoflavones. A statistical central composite design was used to separate all peaks. These multivariate
procedures were efficient in determining the optimal separation condition using resolution, capacity factor, asymmetry and
number of theoretical plates.
相似文献
14.
Nikolai N. Kolesnikov Elena B. Borisenko Dmitrii N. Borisenko Boris A. Gnesin 《Central European Journal of Chemistry》2011,9(4):619-623
In the present study newly produced semiconductor ceramic nanopowder materials made of CdTe and Cd1−xZnxTe (CZT) are considered. Common features and differences in microstructures, phase transformations, grain growth and properties
of the ceramic materials of the binary and ternary compositions are studied.
相似文献
15.
Optimization studies of the procedure for peroxidase activity measurements with DNAzymes based on telomeric sequences and
colorimetric indicator reactions are reported. Effect of metal cation, nature and concentration of surfactant, as well as
thermal treatment of G-quadruplex sample are investigated. Nature of metal cation exhibited modest influence on the system
performance. Great improvement of enzymatic activity of the telomeric quadruplexes in the presence of Brij 58 surfactant was
observed. Further improvement of catalytic activity of the system based on human telomeric sequence was attained by applying
a thermal treatment (heating/rapid cooling) procedure to prepare G-quadruplex/hemin complexes.
相似文献
16.
Sushilkumar A. Jadhav 《Central European Journal of Chemistry》2012,10(2):295-299
New symmetrical disulfides together with the corresponding thiols bearing fluorescent end-groups have been synthesized as
building-blocks for self-assembled monolayers (SAMs). The synthesis has been accomplished starting from aromatic nitrogen
heterocycles in three steps. The conversion of the tosylated intermediate into the final disulfide is accomplished by use
of sodium hydrogen sulfide (NaSH). Both products (thiols and disulfides) were isolated and characterized.
相似文献
17.
Azza A. Shoukry Mohamed M. Shoukry Mohamed N. Hafez 《Central European Journal of Chemistry》2010,8(4):797-805
The kinetics of base hydrolysis of glycine, histidine, and methionine methyl esters in the presence of [Pd(pip)(H2O)2]2+ complex, where pip is piperazine, is studied in aqueous solutions, at T = 25°C, and I = 0.1 mol dm−3. The rate of ester hydrolysis for glycine methyl ester is studied at different temperature and dioxane/water solutions of
different compositions. The kinetic data are fit under the assumption that the hydrolysis proceeds in one step. The activation
parameters for the base hydrolysis of the complexes are evaluated
相似文献
18.
Rodion Yu. Iliashenko Olexiy S. Zozulia Andrey O. Doroshenko 《Central European Journal of Chemistry》2011,9(6):962-971
A series of novel nitro-substituted ortho-analogs of POPOP was synthesized. Like the most of the other known compounds of this class, the synthesized molecules demonstrate
high Stokes shift fluorescence emission owing to the planarization of their molecules at electronic excitation. Significant
fluorescence quenching in polar solvents was described as the “energy gap law” action rather than the specific effect of the
dialkylamino group excited state twisting.
相似文献
19.
The kinetics of the C-S coupling of arylmagnesium bromides with phenyl tosylate has been studied in THF: toluene at 90°C.
The reaction is first order in Grignard reagent and first order in phenyl tosylate. Kinetic data, Hammett relationship and
activation parameters are consistent with a nucleophilic addition mechanism involving rate determining attack of carbanion
to sulfonyl group followed by a fast phenoxide group leaving.
相似文献
20.
M. Teresa Barros Ana I. Mouquinho Krasimira T. Petrova Mara D. Saavedra João C. Sotomayor 《Central European Journal of Chemistry》2011,9(4):557-566
It has been reported that the length of the molecular chain and the rigidity of molecules influence the structure of the polymer
network in PDLC films and hence the electro-optical properties of the composites. Herein, a series of new aromatic monomeric
monomethacrylates, bismethacrylates and monovinylbenzene derivatives with a mesogenic core were successfully synthesized under
microwave irradiation. The microwave assisted synthesis resulted in decreased reaction times, reduced solvent requirement,
increased operational simplicity, and in most cases, improved yields and selectivity.
相似文献