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  • Author or Editor: R. Liu x
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Glutenin subunit alleles at the Glu-D3 locus and their effects on dough properties, pan bread, and dry white Chinese noodle (DWCN) qualities were investigated using 106 winter and facultative wheat cultivars and advanced lines. Allele Glu-D3c (42.5%) was the most frequent glutenin subunit, followed by Glu-D3b (25.5%) and Glu-D3a (23.6%). Glu-D3d and Glu-D3f occurred in only three and six cultivars, respectively. The effect of Glu-D3 was significant forDWCNquality, accounting for up to 16% of the variation, but there were no significant differences between individual Glu-D3 alleles on dough properties and qualities of DWCNand pan bread. Interaction effects Glu-A1 × Glu-D3 and Glu-B1 × Glu-D3 were significant for DWCN quality and loaf volume. More work is needed to understand the effects of Glu-D3 variation on the determination of dough properties and end-use quality.

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A total of 29 major and trace elements have been determined in 43 plant samples collected from the Xizang (Tibet) Plateau using INAA at a SLOWPOKE mini-reactor in order to study elemental background concentration values in Xizang plants. In this paper are reported elemental concentrations of different parts of the plants compared to average values of plants worldwide. The preliminary results suggest that nutritional, plant elements in this region are quite low indicative of a state of malnutrition, while the contents of Al, Ti, Cr and Ba are comparatively high. These findings indicate that the concentrations of most elements in the plants are mainly affected by local soil geochemical characteristics. Some variation in elemental distribution within the plants was also evident: in general, higher concentrations were found in stems compared to roots, and, differences for nutritional elements among the plant species were much greater than found for other elements.

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The thermal decomposition of electrolytic manganese dioxide (EMD), in an inert atmosphere, and the effect of chemical reduction on EMD, using 2-propanol under reflux (82C), was investigated by differential scanning calorimetry (DSC). This study is an extension of a study investigating the thermal decomposition of EMD and reduced EMD by TG-MS (J. Therm. Anal. Cal., 80 (2005)625)). The DSC characterisation was carried out up to 600C encompassing the water loss region up to 390C and the first thermal reduction step. Water removal was observed in two distinct endothermic peaks (which were not deconvolved in the TG-MS) associated with the removal of bound water. For the lower degrees of chemical reduction, thermal reduction resulted in the formation of Mn2O3; for higher degrees of chemical reduction, the thermal reduction resulted in Mn3O4 at 600C. In the DSC the thermal reduction of the EMD and chemically reduced specimen was observed to be endothermic. The reduced specimens, however, also showed an exothermic structural reorganisation.

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A total reflection X-ray fluorescence (TXRF) analyzer with a special structure is described. Its short X-ray path (about 15 cm) resulted in a high sensitivity, low power consumption and small volume. The structure with double total reflection path is suitable for easy change of exciting source to cover a large element range. The minimum detection limit (MDL) of 6 pg for Co under Cu exciting source and 22 pg for Sr under Mo tube. Some significant works were done, such as the detemination of sulfur content in fuel oils, the non-destructive analysis of an ancient bronze utensil and the regular analysis of tap water.

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The thermal decomposition behaviour of the complexes of rare earth metals with histidine: RE(His)(NO3)3 H2O (RE=La—Nd, Sm—Lu and Y; His=histidine) was investigated by means of TG-DTG techniques. The results indicated that the thermal decomposition processes of the complexes can be divided into three steps. The first step is the loss of crystal water molecules or part of the histidine molecules from the complexes. The second step is the formation of alkaline salts or mixtures of nitrates with alkaline salts after the histidine has been completely lost from the complexes. The third step is the formation of oxides or mixtures of oxides with alkaline salts. The results relating to the three steps indicate that the stabilities of the complexes increase from La to Lu.

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The concentrations of seventeen elements in two species of fungus which cause wheat bunt disease,Tilletia caries (DC.) Tul. andTilletia controversa Kühn, were determined by instrumental neutron activation analysis. Differences in the K and Cl concentrations between these two species of spores are large and therefore can be used as a criterion for distinguishing between the two species of fungus.

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In order to identify the kinetic process of self-heating in DSC experiment for Ti+3Al→TiAl3 reaction, two approaches, linear-fitting approach developed from Semenov"s theory of spontaneous ignition and variation of Friedman method, were carried out with cylindrical Ti-75 at% Al samples. Following these approaches, two identical activation energies are obtained as 16915 kJ mol-1 and 1705 kJ mol-1, respectively. Compared with the activation energies of reactions and interdiffusions between Ti and Al, the possible rate-controlling process of self-heating in DSC experiment for Ti+3Al→TiAl3 reaction is the interdiffusion between Ti and Al through TiAl3-layer.

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The effect of sampling conditions on the decomposition of electrolytic manganese dioxide using thermal methods is reported. Significant differences were observed in the mechanism of the decomposition by simply changing the reaction environment from a closed pan to an open pan configuration. The purge gas atmosphere was also observed to influence the decomposition mechanism. As a product of the decomposition is oxygen, the change in the mechanism observed between the experimental conditions may be explained in terms of the ease of removal of oxygen from the reaction site.

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Radioisotopes of 37 elements were isolated from a gold target irradiated with an energetic12C beam and were used as a multitracer to establish procedures for separating themselves into groups of carrier-, salt-and organic matter-free tracers. Solvent extraction with HDEHP and ethyl methyl ketone along with cation exchange yielded group tracers ready for application to chemical and biological studies.

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