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  • Author or Editor: C.H. Zhang x
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Abstract  

The crystallization dynamics of Nylon 66/Nylon 6 blends, the crystalline/crystalline polymer blends, was analyzed by DSC under isothermal conditions. The crystal growth rate (G) and the nucleation rate (N) depended on both the degree of supercooling (ΔT) and the blend mass fraction (ϕ). The ΔT /T m 0 values obtained at the fixed G, which corresponded to the chemical potential difference of molecules between liquid and crystal states, and the surface free energy parameters evaluated from G and N depended on ϕ for blends. The results suggested that Nylon 66/Nylon 6 blends with ϕN66≥0.80 or ϕN66≤0.15 are miscible.

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Abstract  

A new ecomaterial, zirconyl molybdopyrophosphate (ZMPP), was prepared by a coprecipitation method. The removal of Cs+ and Sr2+ ions from simulated strong acid HLLW using the ion exchange process on ZMPP had been investigated. It showed that there are more than 90% Cs+ and Sr2+ removed from the simulated HLLW on ZMPP despite the presence of other metal ions, such as Na+, Al3+, Fe3+, etc. in excess. Then ZMPP may likely be a selective ion exchanger for the removal of 137Cs and 90Sr directly from strong acid HLLW.

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As a new form of traditional Chinese medicine (TCM), Zuojin pill extract is made containing Coptidis rhizoma (the rhizome of Coptis chinesis Franch. [Ranunculaceae]) and Euodiae fructus (the unripe fruit of Euodia rutaecarpa [Juss.] Benth. [Rutaceae]) at the ratio of 6:1 (w/w) and has been most widely used in TCM to treat gastro-intestinal disorders. However, the quality control is insufficient. For establishing an analysis method for the effective quality control of Zuojin pill extract, the active components of three protoberberine alkaloids (coptisine, palmatine, berberine, components from C. rhizoma) and two indolequinoline alkaloids (evodiamine, rutaecarpine, components from E. fructus) in Zuojin pill extract were determined simultaneously by high-performance liquid chromatography. Chromatographic separations were performed on an Inertsil ODS-3 column (4.6 mm × 250 mm, 5 μm). Elution was carried out at 25°C under isocratic conditions by using 25 mmol L−1 KH2PO4-25 mmol L−1 SDS-acetonitrile (1:1:2, v/v/v, adjusted pH to 3.0 using phosphoric acid) as a mobile phase with a flow rate of 0.5 mL min−1. Detection wavelength was set at 264 nm. Good linearity was obtained with correlation coefficient higher than 0.999 for all the analytes over the investigated concentration ranges. Three batches of Zuojin pill extract were successfully analyzed. The average percentages of coptisine, palmatine, berberine, evodiamine, and rutaecarpine in Zuojin pill extract were 5.35%, 3.92%, 16.64%, 0.03%, and 0.03%, respectively. Consequently, these protoberberine and indolequinoline alkaloids could be identified and determined easily by the established high-performance liquid chromatography (HPLC) method which can be used to evaluate and control the quality of Zuojin pill extract.

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Salt stress is one of the major abiotic stress which severely limits plant growth and reduces crop productivity across the world. In the present study, the effects of exogenous pyridoxal-5-phosphate (vitamin B6, VB6) on seedling growth and development of wheat under salt stress were investigated. The results showed that exogenous application of pyridoxal-5-phosphate (VB6) significantly increased the RWC, biomass, the concentration of photosynthetic pigments, proline, the activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), together with decreasing the content of Malondiadehyde (MDA) and hydrogen peroxide (H2O2) in wheat leaves under salt stress. Meanwhile, the transcript level of P5CR, P5CS, SOD, TaSOS1 and TaSOS4 were also up-regulated after treatment with pyridoxal-5-phosphate. VB6 acts as a signal in regulating the activities of plant antioxidant enzymes and SOS pathway to improve resistance to salt stress. The current study results may give an insight into the regulatory roles of VB6 in improving salt stress and VB6 could be an easily and effective method to improve salt-stress tolerance to wheat in the field condition. It is urgency to understand the molecular mechanism of VB6 to enhance the salt tolerance of wheat in the next work.

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Abstract  

A simple operation mode to determine the apparent activation energy E a is introduced. E a can be determined with a double-curve method by using a constant reaction rate (CRR) approach of Hi-Res TG. The most appropriate mechanism function f(α) and frequency factor A are determined by a single-curve method when the activation energies provided by the two methods are in good agreement with each other. The deacetylation of EVA copolymer has been used for illustration. Advantages of the CRR are discussed.

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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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Phenolic extract from banana peel was extracted with 95% ethanol and characterized by LC-TOF-MS/MS. Epicatechin, rutin, 3,4-dihydroxybenzaldehyde, 3,4-dihydroxybenzoic acid, myricetin, ferulic acid, chlorogenic acid, and gallic acid were detected in the extract. Cholate test was performed for the initial examination of the hypolipidemic effect of the dietary fibres. The dietary fibres prepared by sequential treatment with sulphuric acid then sodium hydroxide (SST) and sodium hydroxide treatment (SHT) had high water-holding capacities (7.48 and 6.91 g g−1) and swelling capacities (4.8 and 4.3 ml g−1). The dietary fibres prepared by sequential treatment with trypsin then sulphuric acid (TST) and sulphuric acid treatment (SAT) had high oil-holding capacities (5.52 and 5.10 g g−1) and enhanced capacities for sodium cholate adsorption. Results indicated the potentials of banana peel as functional ingredient in food applications.

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Abstract

In this paper, organic phase change materials (PCM)/Ag nanoparticles composite materials were prepared and characterized for the first time. The effect of Ag nanoparticles on the thermal conductivity of PCM was investigated. 1-tetradecanol (TD) was selected as a PCM. A series of nano-Ag-TD composite materials in aqueous solution were in-situ synthesized and characterized by means of thermal conductivity evaluation method, TG-DSC, IR, XRD and TEM. The results showed that the thermal conductivity of the composite material was enhanced as the loading of Ag nanoparticles increased. The composite materials still had relatively large phase change enthalpy. Their phase change enthalpy could be correlated linearly with the loading of TD, but their phase change temperature was a little bite lower than that of pure TD. The thermal stability of the composite materials was close to that of pure TD. It appeared that there was no strong interaction between the Ag nanoparticles and the TD. Furthermore, the experiment results indicated that the Ag nanoparticles dispersed uniformly in the materials, occurred in the forms of pure metal.

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Abstract  

Ca-47 radioactive tracer was used to determine the phamocodynamics, distribution pattern, absorption and bioavailability of a new type calcium supplement in rabbit prepared by plasma technology. Our results indicate that calcium from the new nutrient is mainly deposited in bone 6 or 7 days after oral administration. The absorption rate of this new calcium preparation is estimated to be 30–40 %.

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Abstract  

The power-time curves of the growth of three strains of petroleum bacteria at different temperatures have been determined. A novel equation of a power-time curve has been proposed in this paper. The general formula to calculate the rate constant of the bacterial growth has been derived. The rate constants of the bacterial growth at different temperatures, the heat production per newly formed bacterium, the bacterial number at the end of the bacterial growth and the deceleration rate constant of the bacterial growth at 50.00°C, have been calculated. The optimum growth temperatures of the three strains have been obtained.

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