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  • Author or Editor: C. Tian x
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Lycopene content (LC) and soluble solid content (SSC) are important quality indicators for cherry tomatoes. This study attempted simultaneous analysis of inner quality of cherry tomato by Electronic nose (E-nose) using multivariate analysis. E-nose was used for data acquisition, the response signals were regressed by multiple linear regression (MLR) and partial least square regression (PLS) to build predictive models. The performances of the predictive models were tested according to root mean square and correlation coefficient (R2) in the training set and prediction set. The results showed that MLR models were superior to PLS model, with higher value of R2 and lower values of for RMSE firmness, pH, SSC, and LC. Together with MLR, E-nose could be used to obtain firmness, pH, soluble solid and lycopene contents in cherry tomatoes.

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In this study, the thermal stability of sisal in cycle process was investigated between room temperatures and 600°C in various conditions (in air, in composites, in argon) by thermogravimetry and mechanical testing measurement. The results indicated that the thermal stability of sisal was worse in air before five times of thermal cycles, but after the five times thermal stability of sisal in composites was better. In different conditions of same cycles process, the thermal stability of sisal was different. With increasing of thermal cycles times, the max. load (is the maximum strength in stress-strain curve) of sisal fiber showed downtendency in different conditions and decreased most obviously in composites.

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The transient hot-wire method is considered the most accurate technique to measure the thermal conductivity of fluids. In this study, a transient hot wire instrument which employs 25.4-μm-diameter tantalum wire with an insulating tantalum pentoxide coating has been used. This hot-wire cell with a thin insulating layer is suitable for measurement of the thermal conductivity of electrically conducting and polar liquids. Measurements of the thermal conductivity of 50 wt% solution of PAA [poly (acrylic acid)] in water and PAA–Na in 50 wt% water are reported here. These measurements were obtained in the temperature range of 299–368 K at 1 atmospheric pressure. The measurement of thermal conductivity is estimated to be accurate within ±4%.

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The dwarf-male-sterile wheat is unique to China and has been improved by introducing good germplasm. In order to clear the subunits background of Dwarf-Male-Sterile wheat, sodium dodecyl sulphate polyacrylamide-gel electrophoresis (SDS-PAGE) was used to detect the high and low molecular weight glutenin subunits (HMW-GS and LMW-GS) compositions in BC1F1, F2 and F3 generations from Dwarf-Male-Sterile wheat. Twenty-five alleles and 49 HMW-GS compositions at the Glu-1 loci were detected in different generations. Null and subunit 1 were mainly existed at Glu-A1 , and 7 + 8 and 7 + 9 were primarily detected at Glu-B1 in different generations. Subunit combination 5 + 10 mainly appeared in BC1F1, while 2 + 12 major presented in F2 and F3 generations. HMW-GS compositions null, 7 + 8, 5 + 10 and null, 7 + 9, 5 + 10 showed higher frequencies than other banding patterns, followed by null, 14 + 15, 5 + 10 and null, 7 + 9, 2 + 12 combinations. In addition, some rare subunit combinations such as 14 + 15, 13 + 16, 17 + 18, 4 + 12, 2 + 10 and 5 + 12 were found in different generations. Eighteen alleles and 51 LMW-GS compositions at Glu-3 loci were found in different generations. Glu-A3 a and Glu-B3 d showed higher frequencies than others among three generations. There were mainly a, b, c alleles at Glu-D3 . Thirty, 31 and 14 different combinations were detected in BC1F1, F2 and F3 populations, respectively. There were some good combinations such as A3 d/ B3 h, A3 d/ B3 d/ D3 a, A3 b/ B3 b/ D3 a, A3 a/ B3 d/ D3 a for different quality characteristics. So some desirable subunit combinations could be selected from different generations and new cultivars with good quality under distinct subunits background should be bred from Dwarf-Male-Sterile wheat in future.

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On the basis of the theory of thermokinetics proposed in the literature, a novel thermokinetic method for determination of the reaction rate, the characteristic parameter method, is proposed in this paper. Mathematical models were established to determine the kinetic parameters and rate constants. In order to test the validity of this method, the saponifications of ethyl benzoate, ethyl acetate and ethyl propionate, and the formation of hexamethylenetetramine were studied with this method. The rate constants calculated with this method are in agreement with those in the literature, and the characteristic parameter method is therefore believed to be correct.In the light of the characteristic parameter method, we have developed further two thermo-kinetic methods, the thermoanalytical single and multi-curve methods, which are convenient for simultaneous determination of the reaction order and the rate constant. The reaction orders and rate constants of the saponifications of ethyl acetate and ethyl butyrate and the ring-opening reaction of epichlorohydrin with hydrobromic acid were determined with these methods, and their validity was verified by the experimental results.

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The thermal degradation of cotton cellulose treated with chemical mixtures containing P and N was studied by thermal analysis, infrared spectroscopy, Char yield and limiting-oxygen-index (LOI). Our experiments demonstrated the following facts. The temperatures and activation energies of pyrolysis were lower for cotton cellulose treated with flame retardants than those for untreated samples and the values of Char yield and LOI were greater for treated cotton than those for untreated one.

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The effects of some kinds of metal ions used as chemical modifications on the thermal properties of the modified polyacrylonitrile (PAN) fibers were studied by DTA, TG, GC and cone calorimetry. The apparent activation energies for the decomposition of the unmodified and modified PAN fibers were determined using Kissinger equation and Broido equation.

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Protein and starch are important in wheat quality and yield. To understand the genetic relationship between protein and starch at the quantitative trait locus (QTL)/gene level, 168 doubled haploid (DH) lines were used at three locations over 2 years. The QTLs for proteinfraction contents and starch content were analyzed by unconditional and conditional QTL mapping. We detected 17 unconditional additive QTLs (four albumin QTLs, three globulin QTLs, six gliadin QTLs, four glutenin QTLs) controlling protein-fraction contents. We detected 19 conditional QTLs (five albumin QTLs, three globulin QTLs, five gliadin QTLs, six glutenin QTLs) based on starch content. Of these QTLs, QAlu1B, QGlo6A, QGli1B, QGli7A, QGlu1B and QGlu1D increased the protein-fraction contents independent of the starch content. These QTLs could regulate the usual inverse relationship between protein and starch in wheat seeds. The results could possibly be used in the simultaneous improvement of grain protein and starch content in wheat breeding.

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The aphid Sitobion avenae F. is one of the most harmful pests of wheat growth in the world. A primary field screening test was carried out to evaluate the S. avenae resistance of 527 wheat landraces from Shaanxi. The results indicated that 25 accessions (4.74%) were resistant to S. avenae in the three consecutive seasons, of which accession S849 was highly resistant, and seven accessions were moderately resistant. The majority of S. avenae resistant accessions come from Qinling Mountains. Then, the genetic variability of a set of 33 accessions (25 S. avenae resistant and 8 S. avenae susceptible) originating from Qinling Mountains have been assessed by 20 morphological traits and 99 simple sequence repeat markers (SSRs). Morphological traits and SSRs displayed a high level of genetic diversity within 33 accessions. The clustering of the accessions based on morphological traits and SSR markers showed significant discrepancy according to the geographical distribution, resistance to S. avenae and species of accessions. The highly and moderately resistant landrace accessions were collected from the middle and the east part of Qinling Mountains with similar morphology characters, for example slender leaves with wax, lower leaf area, and high ear density. These S. avenae resistant landraces can be used in wheat aphid resistance breeding as valuable resources.

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