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The effect of short-term higher ambient temperature (HT) and continuous vibration (CV) treatment was comparatively characterized by sensory evaluation and chemical analysis. Results of quantitative descriptive analysis of modified frequency (MF) showed that HT causes both in red wine and white wine a decrease of fruity and floral characters, an unbalance of taste, and a shortness of aftertaste length. CV wine showed very close sensory characters to control in most terms evaluated. Seventy-four volatile compounds were quantitative analysed by solid phase microextractiongas chromatography-mass spectrometry, and the principal component analysis (PCA) was conducted on the 23 volatiles of highest odour activity value (OAV). The concentrations of potential fruity and floral aroma attributors like isoamyl acetate, ethyl butanoate, ethyl 2-methylbutanoate, ethyl hexanoate, ethyl octanoate, β-damascenone, and linalool were lower in HT wine than that in original wine and CV wine.
Recently food-grade microemulsions have been of increasing interest to researchers and exhibited great potential on their industrial applications. The microbiological and quality characteristics of NuoMiGao, a traditional Chinese steamed rice cake, affected by a prepared food-grade monolaurin-containing microemulsion have been evaluated in this study. Microbiological analysis indicated that 0.05% microemulsion was comparable to 0.01% sodium dehydroacetate, extending the shelf-life by two days. The quality analysis showed that the addition of the microemulsion effectively prevented the hardening phenomena in rice cake; the lightness and yellowness were fairly stable while redness increased slightly (P<0.05); the lowered pH value and the prevention of moisture drop in rice cake were in agreement with the microbiological analysis and hardness trends.
Among the progenies of crossing Triticum turgidum — Haynaldia villosa amphiploid with synthetic hexaploid wheat (T. carthlicum / Aegilops tauschii) Am3, two lines (SN030713 and SN05078), with good resistance to stripe rust and powdery mildew, were developed. Cytological studies demonstrated that SN030713 contained 42 chromosomes and formed 21 bivalents at meiotic metaphase I. SN05078 contained 28 chromosomes and formed 14 bivalents. Genomic in situ hybridization analysis using H. villosa V genomic DNA as the probe showed SN030713 and SN05078 had no large H. villosa chromosome fragments. PCR analysis with H. villosa specific primer pHv29 showed that H. villosa genetic materials were introgressed in these two lines. SSR analysis indicated that the genomic composition of SN030713 was 2n = 6x = 42 (AABBDD), and SN05078 was 2n = 4x = 28 (AABB). Introgressed Ae. tauschii genetic materials in SN05078 were also detected.
Abstract
An isothermal method was applied to measure the thermal decomposition of reactive solids in a sensitive heat flux reaction calorimeter, C80. This technique experimentally clarified the decomposition mechanisms of unstable substances based on the shapes of the heat flow curves, from which autocatalysis, first-order reaction or pseudo-autocatalytic reaction could be recognized. Kinetic parameters were derived from the measured data.
The bread wheat germplasm comprising of 222 accessions was evaluated for tolerance to Sitobion avenae. A 1000-kernel weight loss rate and an unbiased test of the tolerance were used to quantify tolerance trait. The population structure analysis revealed three subpopulations in this wheat collection. After 103 SSR loci which evenly covered all wheat chromosomes were scanned for association, eight SSR loci significantly associated with S. avenae tolerance. The information reported in this study would be helpful for wise utilization of the S. avenae tolerant germplasm and selection of parental lines in wheat breeding programs.
Abstract
Differences of size, content and size distribution of free volumes in linear branched and three-armed polystyrenes, synthesized by radical and anionic processes, were observed by positron annihilation lifetime measurements. The temperature dependence of an average free volume radius was quite similar among polystyrenes of different architectures and molecular weight distributions. The free volume radius increased with temperature, from 0.27 nm (T:60 K) to 0.29 nm (T:260 K) and 0.30 nm (T g:363 K), then to 0.35 nm (423 K), showing turning at and transition temperature. The free volume content decreased from 60 K to 220 K to 300 K showing peculiar minimum at 220 K to 300 K depending on the molecular shape, increased above 320 K, upto 340 to 360 K. The free volume contents decreased with an increase of molecular weight and by an addition of oligomer or plasticiser, suggesting differences in relaxation time or molecular motion between the edge and middle portions of molecular chain and filling effect of smaller molecules in free volumes, respectively. The apparent free volume fraction showed clear variations atT andT g. Size distribution of free volumes suggested more complicated behavior of free volume upon the molecular relaxations and filling effect.
Abstract
Zigetang Lake located in the central Tibetan Plateau was selected for the purpose of understanding of recent sedimentation rates. Based on 137Cs dating marker, the sediment rate was 0.077 cm·yr−1. The sedimentation rate was calculated to be 0.071 cm·yr−1 and 0.029 g·cm−2·yr−1 on the basis of 210Pb CIC model. 210Pb CRS model was also used for understanding of recent sedimentation change. The sediment accumulation rates for the CRS model ranged from 0.022 to 0.038 g·cm−2·yr−1 with an irregular high value of 0.12 g·cm−2·yr−1 around 1932 at Zigetang Lake core in the past eighty years.
Abstract
Nano-ZnO flakes were synthesized by calcination of the precursor of Zn(OH)2 obtained via the reactive ion exchange method between an ion exchange resin and ZnSO4 solution at room temperature. Scanning electron microscopy, X-ray diffraction, energy dispersive X-ray spectroscope, UV-Vis diffuse reflection spectrum and Na2EDTA titration were used to characterize the structure features and chemical compositions of the as-prepared ZnO. The results show that the as-prepared ZnO flakes have uniform structure and high purity. Heat capacities in the temperature range of 83 to 396 K were measured. The measured heat capacities values were compared with those of coarse crystal powders and the difference between this two heat capacity curves was analyzed.
Abstract
The desorption behaviour (desorption temperature and extent of desorption) of HF,HCFC-133a (CF3CH2Cl) and HFC-134a (CF3CH2F) on γ-AlF3 or catalyst supported on γ-AlF3 was studied using an adsorption apparatus and TG, DTA and DSC methods. On the basis of the results a reaction mechanism was proposed for the preparation of HFC-134a. The γ-AlF3 employed for preparing the catalyst was expected to be stable below 550C based on the crystalline phase transition temperature of γ-AlF3.
The refinement of unsaturated fatty acids (UFA) from Hippophae rhamnoides L. seed oil was carried out by molecular distillation (MD) using response surface methodology (RSM). A central composite rotate design was used in order to optimize the experimental parameters: distilling temperature and feed flow. The optimal MD conditions were determined and the quadratic response surfaces were drawn from the mathematical models. The results suggested that the distilling temperature and feed flow significantly affected both the UFA content and oil yield in the two models. The optimum conditions for refining UFA were: distilling temperature 107.5 °C and feed flow 1 ml min−1. Optimal values predicted by RSM for the UFA content and oil yield were 82.38% and 62.59%, respectively. Close agreement between experimental and predicted values was obtained.