A novel method named two-level group contribution （GC-K） method for the estimation of octanol-water partition coefficient （Kow） of chloride hydrocarbon is presented. The equation includes only normal boiling point...A novel method named two-level group contribution （GC-K） method for the estimation of octanol-water partition coefficient （Kow） of chloride hydrocarbon is presented. The equation includes only normal boiling points and molecular weight of compounds. Group contribution parameters of 12 first-level groups and 7 second-level groups for Kow are obtained by correlating experimental data of three types including 57 compounds. By comparing the estimation results of the first-level with that of the two-level groups, it was observed that the latter is better with the addition of the modification of proximity effects. When compared with Marrero＇s three-level group contribution approach and atom-fragment contribution method （AFC）, the accuracy of the average relative error of GC-K by first-level groups is 7.20% and is preferred to other methods.展开更多
The volatile constituents of the essential oil of Hymenocrater longiflorus Benth. growing wild in Kurdistan-Iran were investigated using the GC and GC/MS techniques. Fifteen compounds, representing twenty (97.03%) of ...The volatile constituents of the essential oil of Hymenocrater longiflorus Benth. growing wild in Kurdistan-Iran were investigated using the GC and GC/MS techniques. Fifteen compounds, representing twenty (97.03%) of the total oil were identified. The main components were: α- Pinene (22.47%), β-Caryophyllene (18.05%), β- Eudesmol (14.92%), α-Copaene (9.84%), γ-Elemene (6.79%), δ-Cadine-ne (6.13%), (–)Bornyl acetate (5.61%), α-Amorphene (3.84%), α-Fen- chyl acetate (2.35%) and β-Pinene (2.07%). Some of the physicochemical properties like the logarithm of calculated Octanol-Water partitioning coefficients (log Kow), total biodegradation and (TBd in mol/h and gr./h), water solubility (Sw, mg.L-1 at 25oC) and median lethal concentration 50 (LC50) were calculated for the 15 com- ponents of Hymenocrater longiflorus Benth.展开更多
A two-liquid-phase （TLP） soil slurry system was employed to quantify the efficiencies of autoclaving and mercuric chloride sterilization in the dissipation of polycyclic aromatic hydrocaxbons （PAHs）. The fates of ...A two-liquid-phase （TLP） soil slurry system was employed to quantify the efficiencies of autoclaving and mercuric chloride sterilization in the dissipation of polycyclic aromatic hydrocaxbons （PAHs）. The fates of 11 PAHs （naphthalene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo（a）anthracene, benzo（a）pyrene, benzo（b）fluoranthene, benzo（k）fluoranthene, dibenzo（a, h）anthracene） were recorded over 113 days of incubation. No microorganisms were detected in the HgC12-sterilized soil slurries during the whole incubation period, indicating very effective sterilization. However, about 2% 36% losses of PAHs were observed in the HgCl2- sterilized slurry. In contrast to the HgCl2-sterilized soil slurry, some microorganisms survived in the autoclaved soil slurries. Moreover, significant biodegradiation of 6 PAHs （naphthalene, fluorene, phenanthrene, anthracene, fluoranthene and pyrene） was observed in the autoclaved soil slurries. This indicated that biodegradation results of PAHs in the soil slurries, calculated on basis of the autoclaved control, would be underestimated. It could be concluded that the sterilization efficiency and effectiveness of HgCl2 on soil slurry was much higher than those of autoclaving at 121 ℃ for 45 rain.展开更多
文摘A novel method named two-level group contribution （GC-K） method for the estimation of octanol-water partition coefficient （Kow） of chloride hydrocarbon is presented. The equation includes only normal boiling points and molecular weight of compounds. Group contribution parameters of 12 first-level groups and 7 second-level groups for Kow are obtained by correlating experimental data of three types including 57 compounds. By comparing the estimation results of the first-level with that of the two-level groups, it was observed that the latter is better with the addition of the modification of proximity effects. When compared with Marrero＇s three-level group contribution approach and atom-fragment contribution method （AFC）, the accuracy of the average relative error of GC-K by first-level groups is 7.20% and is preferred to other methods.
文摘The volatile constituents of the essential oil of Hymenocrater longiflorus Benth. growing wild in Kurdistan-Iran were investigated using the GC and GC/MS techniques. Fifteen compounds, representing twenty (97.03%) of the total oil were identified. The main components were: α- Pinene (22.47%), β-Caryophyllene (18.05%), β- Eudesmol (14.92%), α-Copaene (9.84%), γ-Elemene (6.79%), δ-Cadine-ne (6.13%), (–)Bornyl acetate (5.61%), α-Amorphene (3.84%), α-Fen- chyl acetate (2.35%) and β-Pinene (2.07%). Some of the physicochemical properties like the logarithm of calculated Octanol-Water partitioning coefficients (log Kow), total biodegradation and (TBd in mol/h and gr./h), water solubility (Sw, mg.L-1 at 25oC) and median lethal concentration 50 (LC50) were calculated for the 15 com- ponents of Hymenocrater longiflorus Benth.
基金Supported by the National High Technology Research and Development Program (863 Program) of China (No. 2007AA061101)the National Natural Science Foundation of China (Nos. 20707028,4092106,40771104 and 40701078)
文摘A two-liquid-phase （TLP） soil slurry system was employed to quantify the efficiencies of autoclaving and mercuric chloride sterilization in the dissipation of polycyclic aromatic hydrocaxbons （PAHs）. The fates of 11 PAHs （naphthalene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo（a）anthracene, benzo（a）pyrene, benzo（b）fluoranthene, benzo（k）fluoranthene, dibenzo（a, h）anthracene） were recorded over 113 days of incubation. No microorganisms were detected in the HgC12-sterilized soil slurries during the whole incubation period, indicating very effective sterilization. However, about 2% 36% losses of PAHs were observed in the HgCl2- sterilized slurry. In contrast to the HgCl2-sterilized soil slurry, some microorganisms survived in the autoclaved soil slurries. Moreover, significant biodegradiation of 6 PAHs （naphthalene, fluorene, phenanthrene, anthracene, fluoranthene and pyrene） was observed in the autoclaved soil slurries. This indicated that biodegradation results of PAHs in the soil slurries, calculated on basis of the autoclaved control, would be underestimated. It could be concluded that the sterilization efficiency and effectiveness of HgCl2 on soil slurry was much higher than those of autoclaving at 121 ℃ for 45 rain.
