Authors:Y. Li, G. Yang, L. Luo, T. Ke, J. Zhang, K. Li, and G. He
Three wheat varieties of Atlas66 (Al-tolerant genotype), EM12 (a major elite cultivar in China) and Scout66 (Al-sensitive genotype) were used to investigate their potential mechanisms of Al toxicity. Al concentrations of 50, 75, 100 μmol l
were used and the inhibition on root elongation between Scout66 and EM12 is significantly higher than that of Al-tolerant Atlas66, which is negative correlated to the Al absorption in root apices. Organic acids secretion was checked 24 h after Al stress and only malate was detected in Atlas66, but none of the organic acids were detected in the others, suggesting that secretion of malate in root is a major mechanism of Al resistance in Al-tolerant wheat genotype. The root cell ultrastructure showed less damage in Atlas66 than that in Scout66 and EM12 under Al stress by transmission electron microscopy (TEM) technique. Tissue culture was carried out and the callus induction frequencies were all decreased on the media containing Al. The decrease of callus induction frequencies was less in Atlas66 than that in the others. It is concluded that Al damages the cell ultrastructure, resulting in the inhibition of acids secretion and cell division, which implies that the damage of cell ultrastructure is probably the key factor in Al inhibition of root growth.
Authors:F. Zhang, J. Li, X.L. Wang, W. Mao, H. Zhang, J. Guo, and J.W. Li
An allometric analysis of biomass and N mass allocation of rice (Oryza sativa L.) seedlings under non-shaded (100% of full sunlight) and shaded (30% of full sunlight) treatments were conducted. The allometric slopes and the intercepts were estimated using standardized major axis regression. Results indicated that biomass was preferentially allocated to stems during plant ontogeny, and leaves and roots were isometric when rice seedlings were not shaded. Under shade, however, more biomass was allocated to leaves and stems. N mass allocation was also altered by shading in that more N mass was allocated to the aerial shoots, and plants accumulated less N mass when shaded. Our study revealed that both biomass and N mass were in accordance with the optimal partitioning theory.
Authors:S. Wang, L. Xiao, Y. Li, Z. Fang, G. Qiu, and J. Li
A dual cell system was used to study the electrogenerative leaching sphalerite-MnO2 under the conditions of presence and absence of Acidithiobacillus ferrooxidans (A. ferrooxidans). The polarization of anode and cathode, and the relationship between the electric quantity (Q) and some factors, such as the dissolved Zn2+, Fe2+, the time in the bio-electro-generating simultaneous leaching (BEGSL) and electro-generating simultaneous leaching (EGSL),
The results show that the dissolved Zn2+ in the presence of A. ferrooxidans is nearly 60% higher than that in the absence of A. ferrooxidans; the electrogenerative quantity in the former is about 134% more than that in the latter. A three-electrode system was applied
to study anodic and cathodic self-corrosion current, which was inappreciable compared with the galvanic current between sphalerite
and MnO2. The accumulated sulfur on the surface of sulfides produced in the electrogenerative leaching process could be oxidized in
the presence of A. ferrooxidans, and the ratio of biological electric quantity reached to 31.72% in 72 h.
Authors:D. Li, O. Sihamala, S. Bhulaidok, and L. Shen
Edible black ant (
Roger) is a traditional edible insect species in China. It has long been used as an important ingredient of health foods. The aim of the present study was to investigate the changes of organic compounds following sun drying of edible black ant. The results showed that fresh and sun dried edible black ant samples have 28 organic components. Nine of them found in the present study have not been reported previously such as 8-heptadecene and (E,E)-6,10,14-trimethyl-5,9,13-pentadecatrien-2-one. Five constituents disappeared and 4 components formed while the ant was sun dried. The major organic compounds of fresh and sun dried edible black ant belong to fatty acids and hydrocarbons. Some compounds such as fatty acids, aldehyde and alkanes appeared during the procedure indicating that sun drying speeds up lipid oxidation and hydrolytic rancidity.
Authors:Y. Li, Z. Yingyuan, L. Yonghui, J. Jing, and W. Xiaoqing
The enthalpies of mixing of six kinds of amino acid (glycine, L-alanine, L-valine, L-serine, L-threonine, and L-proline) with glycerol in aqueous solutions and the enthalpies of diluting of amino acid and glycerol aqueous solutions have been determined by flow microcalorimetry at 298.15 K. Employing McMillan–Mayer theory, the enthalpies of mixing and diluting have been used to calculate heterogeneous enthalpic pairwise interaction coefficients (hxy) between amino acids and glycerol in aqueous solutions. Combining hxy values of amino acids with glycol in the previous study, the variations of the hxy values between amino acids and glycerol have been interpreted from the point of view of solute–solute interactions.
Authors:L. Xiao, Y. Li, S. Wang, Z. Fang, and G. Qiu
The principle for the electro-generative simultaneous leaching (EGSL) is applied to simultaneous leaching of pyrite-MnO2 in this paper. A galvanic system for the bio-electro-generative simultaneous leaching (BEGSL) has been set up. The equation
of electric quantity vs. time is used to study the effect of produced sulfur on electro-generative efficiency and quantity. It has been shown that
the resistance decreased in the presence of Acidithiobacillus thiooxidans (A. thiooxidans) with the increase of electro-generative efficiency. The effects of temperature and grain size on rate of ferrous extraction
from pyrite under the conditions of presence and absence of A. thiooxidans were studied, respectively. The changes in the extraction rate of Fe2+ as particle size in presence of A. thiooxidans were more evident than that in the absence, which indicated that the extraction in bio-electro-generative leaching was affected
by particle size remarkably. Around the optimum culture temperature for A. thiooxidans, the bigger change in the conversion rate of Fe2+ was depending on temperature. The transferred charge in BEGSL including part of S0 to sulfate group in the presence of (A. thiooxidans) which is called as biologic electric quantity, and the ratio of biologic electric quantity reached to 58.10% in 72 h among
the all-transferred charge.
The effect of itaconic acid (IA) content and heating rate on the stabilization reactions in poly(acrylonitrile-co-itaconic
acid) (P(AN-co-IA)) was investigated by differential scanning calorimetry (DSC) with peak-resolving method. Increasing IA
content was effective in decreasing the initial temperature and the heat evolved, and found to enhance oxidative reactions
to some extent. While, promoting heating rate resulted in a shift of the exotherm to a higher temperature and a more rapid
liberation of heat. The percentage of area of the first exothermic peak increased with increasing heating rate, which would
be attributed to the enhancement of the free radical cyclization reactions.
Authors:W. Guan, L. Li, H. Wang, J. Tong, and J. Yang
A brown and transparent ionic liquid (IL), [C4mim][FeCl4], was prepared by mixing anhydrous FeCl3 with 1-butyl-3-methylimidazolium chloride ([C4mim][Cl]), with molar ratio 1/1 under stirring in a glove box filled with dry argon. The molar enthalpies of solution, ΔsHm, of [C4mim][FeCl4], in water with various molalities were determined by a solution-reaction isoperibol calorimeter at 298.15 K. Considering
the hydrolyzation of anion [FeCl4]− in dissolution process of the IL, a new method of determining the standard molar enthalpy of solution, ΔsHm0, was put forward on the bases of Pitzer solution theory of mixed electrolytes. The values of ΔsHm0 and the sum of Pitzer parameters:
were obtained, respectively. In terms of thermodynamic cycle and the lattice energy of IL calculated by Glasser’s lattice
energy theory of ILs, the dissociation enthalpy of anion [FeCl4]−, ΔHdis≈5650 kJ mol−1, for the reaction: [FeCl4]−(g)→Fe3+(g)+4Cl−(g), was estimated. It is shown that large hydration enthalpies of ions have been compensated by large the dissociation enthalpy
of [FeCl4]− anion, ΔdHm, in dissolution process of the IL.
The molar heat capacity Cp,m of 1,2-cyclohexane dicarboxylic anhydride was measured in the temperature range from T=80 to 390 K with a small sample automated adiabatic calorimeter. The melting point Tm, the molar enthalpy ΔfusHm and the entropy ΔfusSm of fusion for the compound were determined to be 303.80 K, 14.71 kJ mol−1 and 48.43 J K−1 mol−1, respectively. The thermodynamic functions [HT-H273.15] and [ST-S273.15] were derived in the temperature range from T=80 to 385 K with temperature interval of 5 K. The thermal stability of the compound was investigated by differential scanning
calorimeter (DSC) and thermogravimetry (TG), when the process of the mass-loss was due to the evaporation, instead of its