The dissociation rates of methane hydrates formed with and without the presence of sodium dodecyl sulfate （methane-SDS hydrates）, were measured under atmospheric pressure and temperatures below ice point to investig...The dissociation rates of methane hydrates formed with and without the presence of sodium dodecyl sulfate （methane-SDS hydrates）, were measured under atmospheric pressure and temperatures below ice point to investigate the influence of the hydrate production conditions and manners upon its dissociation kinetic behavior. The experimental results demonstrated that the dissociation rate of methane hydrate below ice point is strongly dependent on the manners of hydrate formation and processing. The dissociation rate of hydrate formed quiescently was lower than that of hydrate formed with stirring; the dissociation rate of hydrate formed at lower pressure was higher than that of hydrate formed at higher oressure; the comoaction of hydrate after its formation lowered its stability, i.e., increased＇its dissociation rate.The stability of hydrate could beincreased by prolonging the time period for which hydrate was held at formation temperature and pressure before it was cooled down, or by prolonging the time period for which hydrate was held at dissociation temperature and formation pressure before it was depressurized to atmospheric pressure. It was found that the dissociation rate of methane hydrate varied with the temperature （ranging from 245.2 to 272.2 K） anomalously as reported on the dissociation of methane hydrate without the presence of surfactant as kinetic promoter. The dissociation rate at 268 K was found to be the lowest when the manners and conditions at which hydrates were formed and processed were fixed.展开更多
An aerobic composting method is studied to reuse organic waste from rubb er factory waste as soil fertilizer and to study the effect of cellulolytic microbial activator （CMA） as the activator in the rubber factory w...An aerobic composting method is studied to reuse organic waste from rubb er factory waste as soil fertilizer and to study the effect of cellulolytic microbial activator （CMA） as the activator in the rubber factory waste composting. The performance of the composting process was monitored as a function of carbon and organic matter decomposition rate, temperature and moisture content. The results indicate that the rubber factory waste is best composted with water hyacinth and sludge than composted alone. In addition, the CMA is more aft^ctive when mixed with the rubber factory waste, water hyacinth and sludge since a good fertilizer is achieved. When adding CMA into the rubber factory waste composted alone, the finished product does not achieve a standard of fertilizer, especially the C/N ratio. The finished products （both CMA and without CMA）, can be an environmental friendly alternative to solve the disposal problems of rubber factory waste, Since the C/N ratio, pH, moisture content, temperature, and nutrients of the finished products are acceptable for agriculture use.展开更多
Warming and grazing,and ltter quality jointly determine liter decomposition and nutrient releases in grazing ecosystems.However,their effects have previously been studied in isolation.We conducted a two factorial expe...Warming and grazing,and ltter quality jointly determine liter decomposition and nutrient releases in grazing ecosystems.However,their effects have previously been studied in isolation.We conducted a two factorial experiment with asymmetric warming using infrared heaters and moderate grazing in an alpine meadow.Litter samples were collected from all plots in each treatment,among which some subsamples were placed in their original plots and other samples were translocated to other treatment plots to test the relative effects of each treatment on litter decomposition and nutrient releases.We found that warming rather than grazing alone significantly increased total losses of litter mass,total organic carbon,total nitrogen(TN)and total phosphorus(TP)per unit area due to increases in both mass loss rates and ltter biomass.However,grazing with warming did not affect their total mass losses because increased mass loss was offset by decreased litter biomass compared with the control.Seasonal mean soil temperature better predicted litter decomposition than litter lignin content or carbon to nitrogen ratio.There were interactions between warming and grazing,but there were no interactions between them and litter quality on litter decomposition.The temperature sensitivity of TN loss was higher than that of TP loss per unit area.Our results suggest that increased temperature has a greater effect on litter decomposition and nutrient release than change in litter quality,and that more N release from litter could result in greater P deficiency in the alpine meadow.展开更多
基金Supported by the National Natural Science Foundation of China （20506016, 20676145, U0633003）, the National High Technology Research and Development Program of China （2006AA09A208）, Program for New Century Excellent Talents in Uni versity of the State Ministry of Education （NCET-07-0842）, and the Foundation for the Authors of National Excellent Doc toral Dissertation of the People＇s Republic of China （200447）.
文摘The dissociation rates of methane hydrates formed with and without the presence of sodium dodecyl sulfate （methane-SDS hydrates）, were measured under atmospheric pressure and temperatures below ice point to investigate the influence of the hydrate production conditions and manners upon its dissociation kinetic behavior. The experimental results demonstrated that the dissociation rate of methane hydrate below ice point is strongly dependent on the manners of hydrate formation and processing. The dissociation rate of hydrate formed quiescently was lower than that of hydrate formed with stirring; the dissociation rate of hydrate formed at lower pressure was higher than that of hydrate formed at higher oressure; the comoaction of hydrate after its formation lowered its stability, i.e., increased＇its dissociation rate.The stability of hydrate could beincreased by prolonging the time period for which hydrate was held at formation temperature and pressure before it was cooled down, or by prolonging the time period for which hydrate was held at dissociation temperature and formation pressure before it was depressurized to atmospheric pressure. It was found that the dissociation rate of methane hydrate varied with the temperature （ranging from 245.2 to 272.2 K） anomalously as reported on the dissociation of methane hydrate without the presence of surfactant as kinetic promoter. The dissociation rate at 268 K was found to be the lowest when the manners and conditions at which hydrates were formed and processed were fixed.
文摘An aerobic composting method is studied to reuse organic waste from rubb er factory waste as soil fertilizer and to study the effect of cellulolytic microbial activator （CMA） as the activator in the rubber factory waste composting. The performance of the composting process was monitored as a function of carbon and organic matter decomposition rate, temperature and moisture content. The results indicate that the rubber factory waste is best composted with water hyacinth and sludge than composted alone. In addition, the CMA is more aft^ctive when mixed with the rubber factory waste, water hyacinth and sludge since a good fertilizer is achieved. When adding CMA into the rubber factory waste composted alone, the finished product does not achieve a standard of fertilizer, especially the C/N ratio. The finished products （both CMA and without CMA）, can be an environmental friendly alternative to solve the disposal problems of rubber factory waste, Since the C/N ratio, pH, moisture content, temperature, and nutrients of the finished products are acceptable for agriculture use.
基金the Joint Key Research Fund under a cooperative agreement between the National Natural Science Foundation of China(NSFC)and Tibet Autonomous Region(TAR)(U20A2005)the National Natural Science Foundation of China(41731175,31872994_and 31770524)+1 种基金the Strategic Priority Research Program A of theChineseAcademyof Sciences(XDA20050101)the Second Tibetan Plateau Scientific Expedition and Research(STEP) program(2019QZKK0608 and 2019QZKK0302)。
文摘Warming and grazing,and ltter quality jointly determine liter decomposition and nutrient releases in grazing ecosystems.However,their effects have previously been studied in isolation.We conducted a two factorial experiment with asymmetric warming using infrared heaters and moderate grazing in an alpine meadow.Litter samples were collected from all plots in each treatment,among which some subsamples were placed in their original plots and other samples were translocated to other treatment plots to test the relative effects of each treatment on litter decomposition and nutrient releases.We found that warming rather than grazing alone significantly increased total losses of litter mass,total organic carbon,total nitrogen(TN)and total phosphorus(TP)per unit area due to increases in both mass loss rates and ltter biomass.However,grazing with warming did not affect their total mass losses because increased mass loss was offset by decreased litter biomass compared with the control.Seasonal mean soil temperature better predicted litter decomposition than litter lignin content or carbon to nitrogen ratio.There were interactions between warming and grazing,but there were no interactions between them and litter quality on litter decomposition.The temperature sensitivity of TN loss was higher than that of TP loss per unit area.Our results suggest that increased temperature has a greater effect on litter decomposition and nutrient release than change in litter quality,and that more N release from litter could result in greater P deficiency in the alpine meadow.
