摘要:

AbstractThe viscosity coefficients for the gaseous states of N2and O2and their mixtures are determined at zero and moderately density regimes. The Lennard‐Jones 12–6 (LJ 12–6) potential energy function is used as the initial model potential required y the technique. The interaction potential energies from theinversionprocedure reproduce the viscosity commensurate to the best measurements. The initial density dependence of gaseous viscosity coefficient according to the Rainwater‐Friend theory, which was given by Najafi et al., has been considered for pure N2and

ISSN:0009-4536    

DOI:10.1002/jccs.200800037

出版商:WILEY‐VCH Verlag    

年代:2008

数据来源: WILEY

摘要:

AbstractBy employing one bridging ligand, 2,4‐pyridinedicarboxylate (2,4‐pda2−), three one‐dimensional (1D) coordination polymers of [Cu(2,4‐pda)(H2O)2]∞(1), {[Cu4(2,4‐pda)4(H2O)8]·3H2O}∞(2), and {[Cd(2,4‐pda)(H2O)3]·H2O}∞(3) were synthesized. A simple zigzag polymeric chain is observed for both1and3, but a railroad‐like zigzag polymeric chain is observed for2.Almost all water molecules, whether coordinated or not, are involved in hydrogen bonding interactions and help to tie up the 1D polymeric chains of1‐3into a three‐dimensional (3D) network. A comparison about the coordination geometries in all similar coordination polymers availab

ISSN:0009-4536    

DOI:10.1002/jccs.200800038

出版商:WILEY‐VCH Verlag    

年代:2008

数据来源: WILEY

摘要:

AbstractThe adsorptive voltammetric behavior of resveratrol was studied at a graphite electrode in B‐R buffer (pH = 6.0) solution using adsorptive cyclic voltammetric technique. The oxidation of resveratrol is an irreversible adsorption controlled process. The oxidation mechanism was proposed and discussed in this work. The dependence of the current on pH and the concentration and nature of buffer were investigated to optimize the experimental conditions for the determination of resveratrol. It was found that in the range of 8.0 × 10−9∼ 2.0 × 10−6mol/L, the currents measured by differential pulse voltammetries presented a good linear property as a function of the concentrations of resveratrol. In addition, validation parameters, such as reproducibility, sensitivity and recovery were evaluated as well. The proposed method was also successfully applied for the determination of resveratrol in Chinese patent medicine with goo

ISSN:0009-4536    

DOI:10.1002/jccs.200800039

出版商:WILEY‐VCH Verlag    

年代:2008

数据来源: WILEY

摘要:

AbstractThe complexation reaction between Zn2+, Pb2+, Cd2+and Tl+cations by 5,7‐diiodo‐8‐hydroxyquinoline (IQN) was studied in the Dimethylformamide /Acetonitril (DMF‐AN) binary system using square wave polarography technique. The stoichiometry and stability of the complexes were determined by monitoring the shifts in half‐wave or peak potential of the polarographic waves of metal ions against the ligand concentration. The stoichiometry of the complexes was found to be 1:1. The results obtained show that there is an inverse relationship between the formation constant of the complexes and the donor number of solvent base on the Guttmann donocity scale. In all cases the formation constants increased with increasing amounts of AN in these binary systems. The selectivity order for IQN complexes with the cations is Zn2+>Pb2+

ISSN:0009-4536    

DOI:10.1002/jccs.200800040

出版商:WILEY‐VCH Verlag    

年代:2008

数据来源: WILEY

摘要:

AbstractAn adsorptive differential pulse stripping method for the simultaneous determination of lead and tin is proposed. The procedure involves an adsorptive accumulation of lead and tin on a hanging mercury drop electrode (HMDE), followed by oxidation of adsorbed lead and tin by voltammetric scan using differential pulse modulation. The optimum experimental conditions are: 0.2 mol L−1HNO3, accumulation potential of −900 mV versus Ag/AgCl, accumulation time of 200 s, scan rate of 20 mV s−1and pulse height of 80 mV. Lead and tin peak currents were observed in the same potential region at about −400 mV. The simultaneous determination of lead and tin by using voltammetry is a difficult problem in analytical chemistry, due to voltammogram interferences. The resolution of a mixture of lead and tin by the application of orthogonal signal correction‐partial least squares (OSC‐PLS) was performed. The linear dynamic ranges were 0.003‐0.35 and 0.008‐0.50 μg mL−1and detection limits were land 3 ng mL−1for lead and tin, respectively. The RMSEP for lead and tin with OSC and without OSC were 2.8737, 6.0557 and 8.0941, 9.5151, respectively. The capability of the method for the analysis of real samples was evaluated by the determination of lead and tin in water samples with

ISSN:0009-4536    

DOI:10.1002/jccs.200800041

出版商:WILEY‐VCH Verlag    

年代:2008

数据来源: WILEY

摘要:

AbstractChloroquine phosphate and promethazine hydrochloride are two main components in compound reserpine tablets. It is difficult to separate the two compounds with capillary electrophoresis (CE). Heuristic evolving latent projections (HELP) is a chemometric algorithm which is suitable for resolving overlapped peaks from CE and HPLC. In this paper, HELP was applied to resolving the completely overlapped peaks of chloroquine phosphate and promethazine hydrochloride from CE. Mathematical separation and satisfactory quantification results can be achieved easily without too much time involved in the procedure.

ISSN:0009-4536    

DOI:10.1002/jccs.200800042

出版商:WILEY‐VCH Verlag    

年代:2008

数据来源: WILEY

摘要:

Abstract3‐Amino‐benzo[d]imidazo[2,1‐b]thiazoles were synthesized in moderate to good yields in the presence of NH4Cl via a one pot procedure. All the products were characterized by1H NMR, IR,

ISSN:0009-4536    

DOI:10.1002/jccs.200800043

出版商:WILEY‐VCH Verlag    

年代:2008

数据来源: WILEY

摘要:

AbstractSeveral flavonoids were investigated for the degradation of the HER2/neu (ErbB‐2), while the mechanism is still unknown. A hypothesis was generated here that the inhibition of HER2/neu expression was blocked by heat shock protein 90α (HSP90α) through 1‐benzyl‐3‐(5‐hydroxymethyl‐2‐furyl)indazole (YC‐1) derivatives and flavonoids. In order to ensure the accuracy of the simulated protein structure, the RMSD value between the ligand in crystal structure from PDB and the ligand docking into HSP90α was 1.13 Å. By molecular simulation, the flavonoids and YC‐1 derivatives were employed to dock into HSP90α. The results showed a good correlation between the evaluation scores of the flavonoids/HSP90α complexes and the IC50of flavonoids‐induced degradation of HER2/neu. The YC‐1 derivatives showed higher score values and lower interaction energies on average. Especially, the CLC107 got the highest rank in Potential of Mean Force (PMF) and Dock Score. Luteolin showed the highest dock score and quercetin had the lowest interaction energy of all flavonoid derivatives. This study investigated that the YC‐1 derivatives and the flavonoids may be potent inhibitors for H

ISSN:0009-4536    

DOI:10.1002/jccs.200800044

出版商:WILEY‐VCH Verlag    

年代:2008

数据来源: WILEY

摘要:

AbstractCombined Hartree‐Fock‐Roothaan calculations have been performed using noninteger n Slater type orbitals for the ground states of the lowest electron configurations 1s22s22pn(2 ≤n≤ 6) for negative ions of B, C, N, O and F. These results are compared with the corresponding results obtained from the use of integer n Slater type orbitals. All of the nonlinear parameters are fully optimized. The results of calculation of coupling‐projection coefficients, orbital and total energies and virial ratios are presented. It is shown that the noninteger n Slater type orbitals, in general, improve the orbital

ISSN:0009-4536    

DOI:10.1002/jccs.200800045

出版商:WILEY‐VCH Verlag    

年代:2008

数据来源: WILEY

摘要:

AbstractGlass fibers were characterized for physical and chemical changes before and after subjecting to aging under different environmental conditions. The conditions selected were: low temperature, outdoor atmosphere, indoor atmosphere, chemical environment, 95% humidity&water soaking treatment. The results show that glass fiber is a good candidate to resist sunlight, corrosive atmosphere, low temperature and shady atmosphere. The influence of prolonged time exposure to water caused a detrimental effect on the properties of the glass fiber. Hence, prolonged exposure to water should be avoided for the integrity of the glass fiber under study.

ISSN:0009-4536    

DOI:10.1002/jccs.200800046

出版商:WILEY‐VCH Verlag    

年代:2008

数据来源: WILEY