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  • Author or Editor: Y.H. Wu x
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A detail study of distribution, host range, and seasonal pattern of western flower thrips (WFT), Frankliniella occidentalis (Pergande), in Yunnan Province was conducted in 2004–2006. The pest is distributed throughout the province and was found in 22 out of 25 widely spaced locations surveyed. WFT was found feeding on 45 species of vegetables, ornamentals, and weeds in the province. Seasonal pattern of WFT on vegetables planted in open field and inside greenhouses was similar and, with exception of minor local differences, did not differ from information generated elsewhere. These findings may provide some useful data for the management of this and possibly other thrips pests in Yunnan.

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Adding a magnetic field gradient to the conventional TG system constructs the magnetic thermogravimetry analysis (TG(M) i.e. Faraday methods) and the magnetic derivative thermogravimetry (DTG(M)) techniques. We used the techniques to study the nanocrystalline processes of the FeCuNbSiB and FeCuNbCoSiB amorphous alloys. Some problems of their applications such as the characteristic temperature T min and T C are also discussed in detail.

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Multitracers were prepared by 80 MeV/A 12 C irradiation on thick gold foil at Heavy Ion Research Facility, Institute of Modern Physics, Lanzhou, China. The bulk gold was removed quantitatively from the multitracer solutions with a MIBK-HCl solution.

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Garlic is widely used as food flavouring, and China is the world's largest garlic producer and exporter. To develop a convenient technique for evaluation of garlic cultivars would be worthwhile, and it would have wide application in such a huge market. In this research, 3D front-face fluorescence data of 8 garlic cultivars were recorded, and independent component analysis was used to decompose the overall fluorescence spectra into six independent components. The first, second, and fourth independent components showed a big difference among the cultivars, and the chemical fluorophores behind these three components were specified as protein, vitamin B6, and ATP, respectively, as fluorescent markers for evaluation. The result showed that all 8 cultivars cluster separately. The cultivar “YNQJ” have the highest quality in terms of protein and vitamin B6, “NXYC” and “SDHB” have the highest content of ATP, while “SXXA” is the poorest in terms of protein and ATP, and “HNJZ” has the lowest content of vitamin B6. Therefore, rapid evaluation of garlic cultivars can be accomplished successfully by using only the proportion values of three properly selected fluorescent markers.

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The aim of this study is to investigate the melting/freezing characteristics of paraffin by adding Cu nanoparticles. Cu/paraffin composite phase change materials (PCMs) were prepared by a two-step method. The effects of Cu nanoparticles on the thermal conductivity and the phase change heat transfer of PCMs were investigated by the Hot Disk thermal constants analyzer and infrared monitoring methods, respectively. The maximum thermal conductivity enhancements up to 14.2% in solid state and 18.1% in liquid state are observed at the 2 wt% Cu/paraffin. The photographs of infrared monitoring suggest that the melting and freezing rates of Cu/paraffin are enhanced. For 1 wt% Cu/paraffin, the melting and freezing times can be saved by about 33.3 and 31.6%, respectively. The results provide that adding nanoparticles is an efficient way to enhance the phase change heat transfer of PCMs.

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Patrinia scabra Bunge has long been used in clinic as a traditional Chinese medicine for treating leukemia and cancer and regulating host immune response. Despite their wide use in China, no report on system analysis on their chemical constituents is available so far. The current study was designed to profile the fingerprint of ethyl acetate extract of it, and in addition, to characterize the major fingerprint peaks and determine their quantity. Therefore, a detailed gradient high-performance liquid chromatography was described to separate more than 30 compounds with satisfactory resolution in P. scabra Bunge. Based on the chromatograms of 10 batches samples, a typical high-performance liquid chromatographic (HPLC) fingerprint was established with 23 chromatographic peaks being assigned as common fingerprint peaks. Furthermore, a quadrupole time of flight mass spectrometry (Q-TOF/MS) was coupled for the characterization of major compound. As (+)-nortrachelogenin was the most predominant compound in P. scabra Bunge, the quantification on it was also carried out with the method being validated. As a result, (+)-nortrachelogenin was found to be from 1.33 to 2.21 mg g−1 in this plant material. This rapid and effective analytical method could be employed for quality assessment of P. scabra Bunge, as well as pharmaceutical products containing this herbal material.

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Abstract  

The T and d/dTT curves of the FeCuNbSiB amorphous alloy, which are the relationship between the total saturated magnetic moment per unit mass and temperature, are investigated by magnetic thermogravimetry analysis (TG(M)) technique. It is found that the crystallization process of the samples can be divided into five stages. The studies of samples annealed in temperature range of 480–610°C for 1h show that when the annealing temperature (T a) is less than 540°C, the quantity of nanocrystalline -Fe(Si) phase increases evidently with T a, and the Curie temperature (T C) of residual amorphous phase also increases linearly with T a, i.e. T C=0.52T a+91.7°C, with correlation coefficient =0.98. The variation of volume fraction of -Fe(Si) nanocrystalline phase or residual amorphous phase with T a is measured by TG(M) technique.

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Solvent extraction of protactinium with tri-iso-octyl-amine (TIOA) in xylene, benzene, carbon tetrachloride and chloroform from HCl, HF, HNO3, HClO4 and H2SO4 media was studied using 233Pa as a radiotracer. The extraction efficiencies of protactinium were determined as a function of shaking time, concentrations of mineral acids in aqueous phase, extractant concentrations and diluents in organic phase. The extraction mechanism was discussed. The results show that the extracted species in the organic phase is [(R3NH)nPa(OH)xCl y 5−xy ].

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The uranium(VI) accumulation was studied in detail by using the biomass of mangrove endophytic fungus Fusarium sp.#ZZF51 from the South China Sea. The uranium(VI) biosorption process onto the tested fungus powders was optimized at pH 4.0, adsorption time 60 min, and uranium(VI) initial concentration 50 mg L−1 with 61.89% of removal efficiency. According to Fourier transform infrared spectra for the tested fungus before and after loaded with uranium(VI), the results showed that both of hydroxyl and carboxyl groups acted as the important roles in the adsorption process. In addition, the experimental data were analyzed by using parameter and kinetic models, and it was obtained that the Langmuir isotherm model and the pseudo-second-order kinetic model provided better correlation with the experimental data for adsorption of uranium(VI).

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Abstract  

Over 90% of the cumene hydroperoxide (CHP) produced in the world is applied in the production of phenol and acetone. The additional applications were used as a catalyst, a curing agent, and as an initiator for polymerization. Many previous studies from open literature have verified and employed various aspects of the thermal decomposition and thermokinetics of CHP reactions. An isothermal microcalorimeter (thermal activity monitor III, TAM III), and a thermal dynamic calorimetry (differential scanning calorimetry, DSC) were used to resolve the exothermic behaviors, such as exothermic onset temperature (T 0), heat power, heat of decomposition (ΔH d), self-heating rate, peak temperature of reaction system, time to maximum rate (TMR), etc. Furthermore, Fourier transform infrared (FT-IR) spectrometry was used to analyze the CHP products with its derivatives at 150 °C. This study will assess and validate the thermal hazards of CHP and incompatible reactions of CHP mixed with its derivatives, such as acetonphenone (AP), and dimethylphenyl carbinol (DMPC), that are essential to process safety design.

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