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  • Author or Editor: H. Jiang x
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Abstract  

Recently P. Mache and M. W. Müller introduced the Baskakov quasi-interpolants and obtained an approximation equivalence theorem. In this paper we consider simultaneous approximation equivalence theorem for Baskakov quasi-interpolants.

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Abstract  

Brief description for the projects and advances of isotope tracer and radiation technology applied in Chinese oil field monitoring is given.

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Abstract  

The dehydration process of Co(II), Cu(II) and Zn(II) methanesulfonates was studied by thermogravimetry/derivative thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC) techniques in dynamic N2 atmosphere. The TG/DTG curves show that all of them contain four crystallization water molecules, which are lost in two steps. The peak temperature and dehydration enthalpies ΔH were measured from DSC curves for each compound. The effect of procedural variables on the TG and DSC curves was investigated. In this work, the procedural variables included heating rate, Al pan state (unsealed and sealed) and sample mass.

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Abstract  

Ammonium niobium oxalate was prepared and characterized by elemental analysis, XRD and FTIR spectroscopy analysis, which confirmed that the molecular formula of the complex is NH4(NbO(C2O4)2(H2O)2)(H2O)3. Dynamic TG analysis under air was used to investigate the thermal decomposition process of synthetic ammonium niobium oxalate. It shows that the thermal decomposition occurs in three stages and the corresponding apparent activation energies were calculated with the Ozawa–Flynn–Wall and the Friedman methods. The most probable kinetic models of the first two steps decomposition of the complex have been estimated by Coats–Redfern integral and the Achar–Bridly–Sharp differential methods.

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Abstract  

The thermal decompositions of dehydrated or anhydrous bivalent transition metal (Mn, Fe, Co, Ni, Cu, Zn, Cd) and alkali rare metal (Mg, Ca, Sr, Ba) methanesulfonates were studied by TG/DTG, IR and XRD techniques in dynamic Air at 250–850 °C. The initial decomposition temperatures were calculated from TG curves for each compound, which show the onsets of mass loss of methanesulfonates were above 400 °C. For transition metal methanesulfonates, the pyrolysis products at 850 °C were metal oxides. For alkali rare metal methanesulfonates, the pyrolysis products at 850 °C of Sr and Ba methanesulfonates were sulphates, while those of Mg and Ca methanesulfonate were mixtures of sulphate and oxide.

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Abstract  

Hydrated methanesulfonates Ln(CH3SO3)3 nH2O (Ln=La, Ce, Pr, Nd and Yb) and Zn(CH3SO3)2 nH2O were synthesized. The effect of atmosphere on thermal decomposition products of these methanesulfonates was investigated. Thermal decomposition products in air atmosphere of these compounds were characterized by infrared spectrometry, the content of metallic ion in thermal decomposition products were determined by complexometric titration. The results show that the thermal decomposition atmosphere has evident effect on decomposition products of hydrated La(III), Pr(III) and Nd(III) methanesulfonates, and no effect on that of hydrated Ce(III), Yb(III) and Zn(II) methanesulfonates.

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Summary

A high-performance liquid chromatographic (HPLC) method has been developed for separation and quantitative analysis of flavonoid aglycones in Rhododendron anthropogonosides Maxim. Flavonoids in their bound forms were hydrolyzed with acid before HPLC analysis. Analytical samples were pretreated by solid-phase extraction on C18 reversed-phase cartridges. Optimum separation on a 4.6 mm × 250 mm i.d. C18 column was achieved by use of a 52:48 (v/v) mixture of methanol and an aqueous solution of 10 mm citric acid and 1 mm sodium dodecyl sulfate as mobile phase. The flow rate was 1.0 mL min–1 and the detection wavelength 360 nm. Five flavonoids, myricetin, quercetin, luteolin, kaempferol, and isorhamnetin, were separated with high resolution without use of gradient elution. The method was successfully used for efficient quality-control analysis by quantifying flavonoids in R. anthopogonosides. Repeatability tests showed that intra-day and inter-day RSD was <10%. LOD of the five flavonoids were <0.85 μg mL–1. Recovery ranged from 90.2 to 112.5%, with RSD <11.1%.

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Abstract  

Co-combustion experiments of mixture of Huadian oil shale and Heshan coal with high sulphur content have been conducted using a thermogravimetric analyzer. The effects of five different Ca/S mol ratios on the combustion characteristics of mixture fuel are analyzed using TG and DTG curves. The results show that the initial temperature of combustion of mixture fuel is decreased with an increase in the oil shale content of mixture fuel. The combustion characteristic of mixture fuel is superior to that of Heshan coal. Adding about 20 mass% Huadian oil shale into Heshan coal is feasible for desulfurization of mixture fuel during combustion.

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In the natural populations of common wheat landrace Kaixianluohanmai, there was a phKL gene which promotes homoeologous pairing of wheat-alien hybrids. In the present study, the effects of phKL gene on crossability and homoeologous pairing of Triticum aestivum × Psathyrostachys huashanica Keng ex Kuo hybrids were comparatively analyzed. The crossability of the hybrid between Sichuan wheat landrace Kaixianluohanmai and P. huashanica was highest in all the hybrid combinations with 3.18%. The hybrids T. aestivum (Kaixianluohanmai) × P. huashanica showed a pairing configuration of 21.70 univalents + 2.68 rod bivalents + 0.34 ring bivalents + 0.06 trivalents + 0.02 quadrivalents and 3.54 chiasma per PMC at MI. However, the chiasma in hybrids of CS, CS ph1b , CS ph2a and CS ph2b with P. huashanica was 0.56, 1.90, 0.87 and 0.60, respectively. Compared with the hybrids of CS, CS ph1b , CS ph2a and CS ph2b with P. huashanica , a significant increase in the chiasma of homoeologous pairing was observed in the hybrids of T. aestivum (Kaixianluohanmai) × P. huashanica . The effects were shown in the increment of rod bivalents, ring bivalents and trivalents and reduction of univalents. The results indicated that phKL showed a higher effect on promoting homoeologous pairing than ph1 and ph2 in T. aestivum × P. huashanica . The wheat landrace Kaixianluohanmai with phKL gene is probably a more desirable material for alien gene transferring than Ph2 -deficiency lines.

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