A relationship is established, using the least squares method, between the standard enthalpy of formation and the standard enthalpy of formation divided by the exothermic denitration decomposition peak absolute temper...A relationship is established, using the least squares method, between the standard enthalpy of formation and the standard enthalpy of formation divided by the exothermic denitration decomposition peak absolute temperature corresponding to β →0.展开更多
The thermal decomposition temperature is one of the most important parameters to evaluate fire hazard of organic peroxide. A quantitative structure-property relationship model was proposed for estimating the thermal d...The thermal decomposition temperature is one of the most important parameters to evaluate fire hazard of organic peroxide. A quantitative structure-property relationship model was proposed for estimating the thermal decomposition temperatures of organic peroxides. The entire set of 38 organic peroxides was at random divided into a training set for model development and a prediction set for external model validation. The novel local molecular descriptors of AT1, AT2, AT3, AT4, AT5, AT6 and global molecular descriptor of ATC have been proposed in order to character organic peroxides’ molecular structures. An accurate quantitative structure-property relationship （QSPR） equation is developed for the thermal decomposition temperatures of organic peroxides. The statistical results showed that the QSPR model was obtained using the multiple linear regression （MLR） method with correlation coefficient （R）, standard deviation （S）, leave-one-out validation correlation coefficient （RCV） values of 0.9795, 6.5676 ℃ and 0.9328, respectively. The average absolute relative deviation （AARD） is only 3.86% for the experimental values. Model test by internal leave-one-out cross validation and external validation and molecular descriptor interpretation were discussed. Comparison with literature results demonstrated that novel local and global descriptors were useful molecular descriptors for predicting the thermal decomposition temperatures of organic peroxides.展开更多
Plant residue application is an important way to maintain soil productivity. In order to determine whether walnut leaf can be returned to soil or not and get the conditions of efficient decomposition, the effect of wa...Plant residue application is an important way to maintain soil productivity. In order to determine whether walnut leaf can be returned to soil or not and get the conditions of efficient decomposition, the effect of walnut （Juglans sigillata Dode） leaf decomposition under various conditions （different temperatures, durations and leaf-soil ratios） upon soil chemicals and biological properties were analyzed. Compared with the original soil, adding walnut leaf to soil could decrease soil pH, increase EC, nutrient contents, microbial quantity and enzyme activities. Total nitrogen, total organic carbon and organic matter increased with the increasing of decomposition duration, temperature and leaf-soil ratio. Enzyme activities changed with different decomposition conditions, but the highest activities of alkaline phosphatase and catalase were associated with the lower temperature （15℃）, the highest concentration （10 ： 100） and the shortest duration （0 day）. Walnut leaves decomposition for 20 or 30 days at 15℃ and with 10 ： 100 ratio significantly promoted bacteria, fungi and the total microbial quantity. Walnut leaves can be returned to soil because their decomposition could improve relevant indicators of soil fertility, decomposition conditions as shorter durations （20 days）, lower temperature （ 15 ℃） and higher concentrations of leaves （ 10 ： 100） were the more effective decomposition conditions for walnut leaves.展开更多
文摘A relationship is established, using the least squares method, between the standard enthalpy of formation and the standard enthalpy of formation divided by the exothermic denitration decomposition peak absolute temperature corresponding to β →0.
基金Project(2015SK20823) supported by Science and Technology Project of Hunan Province,ChinaProject(15A001) supported by Scientific Research Fund of Hunan Provincial Education Department,China+2 种基金Project(2017CL06) supported by Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation,ChinaProject(k1403029-11) supported by Science and Technology Project of Changsha City,ChinaProject(CX2015B372) supported by the Hunan Provincial Innovation Foundation for Postgraduate,China
文摘The thermal decomposition temperature is one of the most important parameters to evaluate fire hazard of organic peroxide. A quantitative structure-property relationship model was proposed for estimating the thermal decomposition temperatures of organic peroxides. The entire set of 38 organic peroxides was at random divided into a training set for model development and a prediction set for external model validation. The novel local molecular descriptors of AT1, AT2, AT3, AT4, AT5, AT6 and global molecular descriptor of ATC have been proposed in order to character organic peroxides’ molecular structures. An accurate quantitative structure-property relationship （QSPR） equation is developed for the thermal decomposition temperatures of organic peroxides. The statistical results showed that the QSPR model was obtained using the multiple linear regression （MLR） method with correlation coefficient （R）, standard deviation （S）, leave-one-out validation correlation coefficient （RCV） values of 0.9795, 6.5676 ℃ and 0.9328, respectively. The average absolute relative deviation （AARD） is only 3.86% for the experimental values. Model test by internal leave-one-out cross validation and external validation and molecular descriptor interpretation were discussed. Comparison with literature results demonstrated that novel local and global descriptors were useful molecular descriptors for predicting the thermal decomposition temperatures of organic peroxides.
基金Supported by Guizhou Science and Technology Major Project([2011]6011)the National Key Technology R&D Program(2014BAD23B03)
文摘Plant residue application is an important way to maintain soil productivity. In order to determine whether walnut leaf can be returned to soil or not and get the conditions of efficient decomposition, the effect of walnut （Juglans sigillata Dode） leaf decomposition under various conditions （different temperatures, durations and leaf-soil ratios） upon soil chemicals and biological properties were analyzed. Compared with the original soil, adding walnut leaf to soil could decrease soil pH, increase EC, nutrient contents, microbial quantity and enzyme activities. Total nitrogen, total organic carbon and organic matter increased with the increasing of decomposition duration, temperature and leaf-soil ratio. Enzyme activities changed with different decomposition conditions, but the highest activities of alkaline phosphatase and catalase were associated with the lower temperature （15℃）, the highest concentration （10 ： 100） and the shortest duration （0 day）. Walnut leaves decomposition for 20 or 30 days at 15℃ and with 10 ： 100 ratio significantly promoted bacteria, fungi and the total microbial quantity. Walnut leaves can be returned to soil because their decomposition could improve relevant indicators of soil fertility, decomposition conditions as shorter durations （20 days）, lower temperature （ 15 ℃） and higher concentrations of leaves （ 10 ： 100） were the more effective decomposition conditions for walnut leaves.
