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Abstract  

In 1999 investigation, the needles of Sabina chinesis L. from 11 hot spot tourist cities extending over China were collected as biomonitors for evaluation of atmospheric elemental differences in those cities. Thirty five elements were determined by instrumental neutron activation analysis (INAA). The experimental data reflected the environmental alteration in the cities that have different geographical position, population burden and industrialized level. Eventually by using the data processed by factor analysis (FA) and subsequent cluster analysis (CA), the cities were grouped into six sorts of the urban atmospheric deposition with corresponding elements.

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Abstract  

Heat capacities of both the ingot-like and melt-spun Al-Sr alloys have been measured through the temperature range 373 to 1060 K using differential scanning calorimetry. The experimental results show that rapid solidification has a slight effect on the temperature dependence of the heat capacities of the Al-Sr alloys. The heat capacities of the melt-spun Al-Sr alloys increase more slowly than those of the ingot-like alloys with increasing temperature from 373 to 900 K. Furthermore, the effect of rapid solidification on the heat capacities becomes more obvious with increasing Sr concentration in the Al-Sr alloys. The data of the heat capacities between 373 and 900 K have been fitted with the least square method and a linear dependence on temperature was assumed for that temperature range.

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Abstract  

Five column experiments have been carried out to investigate the effect of flow rate on the breakthrough curves (BTCs) of phosphate, fulvic acid, and uranium(VI) onto a silica column. Both BTCs of phosphate and fulvic acid, and three BTCs of uranium(VI) in the presence and absence of phosphate or fulvic acid at high flow rate published in the previous paper [<cite>1</cite>] were compared with corresponding initial parts of BTCs at low flow rate in this paper. Each BTC in this paper was expressed as both C/Co–t and C/Co–V/Vo plots, where C and Co are the concentrations in the influent and the effluent respectively, t and V are the time and the effluent volume from the start of injection of pulse solution respectively, Vo is the pore volume of the SiO2 column. Based on the experimental results and the relationship among V, t, and flow rate F, it was found that there are advantages to using C/Co–V/Vo plot as BTC to study the effect of flow rate. Based on these comparisons of C/Co–V/Vo plots at different flow rates and the theoretical analysis from the Bohart–Adams sorption model, it was found that the right shift (increase in V/Vo of breakthrough), the left shift (decrease in V/Vo of breakthrough), and the non-shift (non-change in V/Vo of breakthrough) of initial parts of BTCs with increasing flow rate are certain to occur instead of only left shift and that three different trends of shifts can be mainly attributed to different rate-controlling mechanisms of sorption process.

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Abstract  

The concentrations of extractable organohalogens (EOX) and extractable persistent organohalogens (EPOX) in placenta, umbilical cord and hair of mothers delivering disabled or normal newborns as well as the compositions of EPOCl in three analyzed matrices were determined by a combination of NAA, gas chromatography and chemical separation. The results indicated that both EOX and EPOX decreased in the order: hair > umbilical cord > placenta. Organochlorines were the major fraction of organohalogens. More than 77% of EPOCl were unidentified. High organohalogens exposure may induce adverse health effects, and hair, as a biomonitor for organohalogens assessment, is more recommendable.

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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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Abstract  

A method of efficiency calibration for the measurement of 88Kr and 138Xe by HPGe γ-spectrometer is proposed in the present paper. The question for the efficient calibration is, how to achieve homogeneous sources of 88Kr-88Rb and 138Xe-138Cs. The fission product gases were obtained by irradiating a precisely measured amount of U3O8 (90% 235U) filled in a quartz glass ampoule. Source cell was first filled up with stearic acid, and then the fission product gases were charged into it. Xenon and krypton are not adsorbed on stearic acid, therefore, homogeneous sources of 88Kr-88Rb and 138Xe-138Cs can be prepared. The results of the experiment demonstrate that the method is feasible and successful.

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Thermodynamic investigation of room temperature ionic liquid

Heat capacity and thermodynamic functions of BMIBF4

Journal of Thermal Analysis and Calorimetry
Authors: Z. Zhang, Z. Tan, Y. Li, and L. Sun

Abstract  

The molar heat capacities of the room temperature ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate (BMIBF4) were measured by an adiabatic calorimeter in temperature range from 80 to 390 K. The dependence of the molar heat capacity on temperature is given as a function of the reduced temperature X by polynomial equations, C P,m (J K–1 mol–1)= 195.55+47.230 X–3.1533 X 2+4.0733 X 3+3.9126 X 4 [X=(T–125.5)/45.5] for the solid phase (80~171 K), and C P,m (J K–1 mol–1)= 378.62+43.929 X+16.456 X 2–4.6684 X 3–5.5876 X 4 [X=(T–285.5)/104.5] for the liquid phase (181~390 K), respectively. According to the polynomial equations and thermodynamic relationship, the values of thermodynamic function of the BMIBF4 relative to 298.15 K were calculated in temperature range from 80 to 390 K with an interval of 5 K. The glass translation of BMIBF4 was observed at 176.24 K. Using oxygen-bomb combustion calorimeter, the molar enthalpy of combustion of BMIBF4 was determined to be Δc H m o= – 5335±17 kJ mol–1. The standard molar enthalpy of formation of BMIBF4 was evaluated to be Δf H m o= –1221.8±4.0 kJ mol–1 at T=298.150±0.001 K.

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Abstract  

Intact chloroplasts were isolated from mesophyll protoplasts of Brassia napus. Concentrations of 8 rare earth elements (REEs) in the chloroplasts were determined by instrumental neutron activation analysis (INAA). The results showed that there were trace amounts of REEs in the chloroplasts, which corresponded to 1 atom of REEs per 2000 chlorophyll molecules. About 30% of the total REEs in the leaves are localized in the chloroplasts and the light REEs were enriched with respect to the heavy elements of the series.

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Abstract  

The contents of eight rare earth elements (La, Ce, Nd, Sm, Eu, Tb, Yb and Lu) in various plant species taken from a rare earth ore area were determined by instrumental neutron activation analysis. For a given plant, the REE patterns in root, leaf and host soil are different from each other. The REE distribution characteristics in roots of various species are very similar and resemble those in the surface water. The results of this study suggest that there is no significant fractionation between the REEs during their uptake by the plant roots from soil solution. However, the variation of the relative abundance of individual REE occurs in the process of transportation and deposition of REEs in plants.

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