The adhesion mechanics of coal and the behavior of the coal adhesion to the hopper are analyzed. A model coal hopper is developed, and the model experiments are made by using the surface electro osmosis technology ac...The adhesion mechanics of coal and the behavior of the coal adhesion to the hopper are analyzed. A model coal hopper is developed, and the model experiments are made by using the surface electro osmosis technology according to the processing conditions. The parameters of the surface electro osmosis technology are optimized by the method of orthogonal polynomial regression designing. The result shows that the surface electro osmosis technique is one of the good methods to solve the adhering problem of coal to the coal hopper in transfer piping.展开更多
A simulated experimental reduction of and the synthesis of uraninite by a sulfate-reducing bacteria, Desulfovibrio desulfuricans DSM 642, are first reported. The simulated physicochemical experimental conditions were:...A simulated experimental reduction of and the synthesis of uraninite by a sulfate-reducing bacteria, Desulfovibrio desulfuricans DSM 642, are first reported. The simulated physicochemical experimental conditions were: 35°C, pH=7.0-7.4, corresponding to the environments of formation of the sandstone-hosted interlayer oxidation-zone type uranium deposits in Xinjiang, NW China. Uraninite was formed on the surface of the host bacteria after a one-week's incubation. Therefore, sulfate-reducing bacteria, which existed extensively in Jurassic sandstone-producing environments, might have participated in the biomineralization of this uranium deposit. There is an important difference in the order- disorder of the crystalline structure between the uraninite produced by Desulfovibrio desulfuricans and naturally occurring uraninite. Long time and slow precipitation and growth of uraninite in the geological environment might have resulted in larger uraninite crystals, with uraninite nanocrystals arranged in order, whereas the experimentally produced uraninite is composed of unordered uraninite nanocrystals which, in contrast, result from the short time span of formation and rapid precipitation and growth of uraninite. The discovery has important implications for understanding genetic significance in mineralogy, and also indicates that in-situ bioremediation of U-contaminated environments and use of biotechnology in the treatment of radioactive liquid waste is being contemplated.展开更多
With the development of large scale text processing, the dimension of text feature space has become larger and larger, which has added a lot of difficulties to natural language processing. How to reduce the dimension...With the development of large scale text processing, the dimension of text feature space has become larger and larger, which has added a lot of difficulties to natural language processing. How to reduce the dimension has become a practical problem in the field. Here we present two clustering methods, i.e. concept association and concept abstract, to achieve the goal. The first refers to the keyword clustering based on the co occurrence of展开更多
Tbe experimental simulation has been performed to investigate the smoke flowing properties within the 1/5 reduced-scale model of a sleeping carriage. The velocity field of the running train on fire is simulated in a w...Tbe experimental simulation has been performed to investigate the smoke flowing properties within the 1/5 reduced-scale model of a sleeping carriage. The velocity field of the running train on fire is simulated in a wind tunnel of the State Key Lab of Fire Science, USTC (University of Science & Technology of China). In this paper, the fire-smoking properties and the variation of the temperature field in the sleeping carriage are analyzed. This paper introduces the simulation method of reducedscale experiment about the running train and the analysis or the experimental data. It provides the basis of experiment for the running train’s fire-safety and full-scale experiment in the future study.展开更多
Pharmaceuticals are present in the environment from anthropogenic pollution sources,leading to groundwater contamination when reaching urban aquifers.Once in the subsurface,their fate depends on the hydrochemical proc...Pharmaceuticals are present in the environment from anthropogenic pollution sources,leading to groundwater contamination when reaching urban aquifers.Once in the subsurface,their fate depends on the hydrochemical processes and environmental conditions within the aquifer.In this context,this study investigates how different redox and temperature conditions affect the natural attenuation of pharmaceuticals in the subsurface.Batch experiments were conducted under oxic and suboxic(i.e.,up to nitrate reduction)conditions and at two temperatures(25℃ and 35℃).The controlled conditions achieved with parallel batch reactor systems allowed us a systematic investigation of the processes and factors involved in the fate of ten pharmaceuticals(atenolol,citalopram,climbazole,irbesartan,lamo-trigine,sitagliptin,carbamazepine,metoprolol,trimethoprim,and venlafaxine),providing insights into the mechanisms governing their attenuation.The results showed that oxic conditions were highly effective in reducing pharmaceuticals concentrations,achieving up to 91%attenuation for irbesartan,followed by citalopram(90%),climbazole(77%),sitagliptin(76%)and metoprolol(75%).Atenolol and climbazole were also attenuated regardless of redox conditions.High temperatures increased the total removal of citalopram,irbesartan,sitagliptin,and trimethoprim by 5–12%,while slightly enhancing the sorption affinity of carbamazepine,irbesartan,and atenolol by 5%.However,trimethoprim,carba-mazepine,and lamotrigine were the most persistent compounds,with average removal rates of 6%,15%,and 24%,respectively.Overall,more than half of the targeted pharmaceuticals showed significant average removal(>60%),highlighting the influence of the processes involved in groundwater on the natural attenuation of these compounds.Sorption seemed to be the primary process contributing to the target pharmaceuticals attenuation in oxic conditions,while biodegradation played a secondary role,particularly for atenolol and metoprolol.These findings contribute to improve our understanding of the behaviour of pharmaceuticals in aquatic environment and thus to improve management practices for better water quality.展开更多
文摘The adhesion mechanics of coal and the behavior of the coal adhesion to the hopper are analyzed. A model coal hopper is developed, and the model experiments are made by using the surface electro osmosis technology according to the processing conditions. The parameters of the surface electro osmosis technology are optimized by the method of orthogonal polynomial regression designing. The result shows that the surface electro osmosis technique is one of the good methods to solve the adhering problem of coal to the coal hopper in transfer piping.
基金the National Science Foundation.USA.(NSF Grant EAR 02-10820)the National Natural ScienceFoundation of China(NSFC Grant No.40173031)+1 种基金the International Cooperative Research Foundation of NSFC(Grant No.2002-40210104086) the Ph.D.Base Foundation of the Ministry of Education of China(Grant No.20020284036).
文摘A simulated experimental reduction of and the synthesis of uraninite by a sulfate-reducing bacteria, Desulfovibrio desulfuricans DSM 642, are first reported. The simulated physicochemical experimental conditions were: 35°C, pH=7.0-7.4, corresponding to the environments of formation of the sandstone-hosted interlayer oxidation-zone type uranium deposits in Xinjiang, NW China. Uraninite was formed on the surface of the host bacteria after a one-week's incubation. Therefore, sulfate-reducing bacteria, which existed extensively in Jurassic sandstone-producing environments, might have participated in the biomineralization of this uranium deposit. There is an important difference in the order- disorder of the crystalline structure between the uraninite produced by Desulfovibrio desulfuricans and naturally occurring uraninite. Long time and slow precipitation and growth of uraninite in the geological environment might have resulted in larger uraninite crystals, with uraninite nanocrystals arranged in order, whereas the experimentally produced uraninite is composed of unordered uraninite nanocrystals which, in contrast, result from the short time span of formation and rapid precipitation and growth of uraninite. The discovery has important implications for understanding genetic significance in mineralogy, and also indicates that in-situ bioremediation of U-contaminated environments and use of biotechnology in the treatment of radioactive liquid waste is being contemplated.
文摘With the development of large scale text processing, the dimension of text feature space has become larger and larger, which has added a lot of difficulties to natural language processing. How to reduce the dimension has become a practical problem in the field. Here we present two clustering methods, i.e. concept association and concept abstract, to achieve the goal. The first refers to the keyword clustering based on the co occurrence of
文摘Tbe experimental simulation has been performed to investigate the smoke flowing properties within the 1/5 reduced-scale model of a sleeping carriage. The velocity field of the running train on fire is simulated in a wind tunnel of the State Key Lab of Fire Science, USTC (University of Science & Technology of China). In this paper, the fire-smoking properties and the variation of the temperature field in the sleeping carriage are analyzed. This paper introduces the simulation method of reducedscale experiment about the running train and the analysis or the experimental data. It provides the basis of experiment for the running train’s fire-safety and full-scale experiment in the future study.
基金supported by the project MAGH(2021-SGR-00308)financed by the AGAUR(Catalan Government)。
文摘Pharmaceuticals are present in the environment from anthropogenic pollution sources,leading to groundwater contamination when reaching urban aquifers.Once in the subsurface,their fate depends on the hydrochemical processes and environmental conditions within the aquifer.In this context,this study investigates how different redox and temperature conditions affect the natural attenuation of pharmaceuticals in the subsurface.Batch experiments were conducted under oxic and suboxic(i.e.,up to nitrate reduction)conditions and at two temperatures(25℃ and 35℃).The controlled conditions achieved with parallel batch reactor systems allowed us a systematic investigation of the processes and factors involved in the fate of ten pharmaceuticals(atenolol,citalopram,climbazole,irbesartan,lamo-trigine,sitagliptin,carbamazepine,metoprolol,trimethoprim,and venlafaxine),providing insights into the mechanisms governing their attenuation.The results showed that oxic conditions were highly effective in reducing pharmaceuticals concentrations,achieving up to 91%attenuation for irbesartan,followed by citalopram(90%),climbazole(77%),sitagliptin(76%)and metoprolol(75%).Atenolol and climbazole were also attenuated regardless of redox conditions.High temperatures increased the total removal of citalopram,irbesartan,sitagliptin,and trimethoprim by 5–12%,while slightly enhancing the sorption affinity of carbamazepine,irbesartan,and atenolol by 5%.However,trimethoprim,carba-mazepine,and lamotrigine were the most persistent compounds,with average removal rates of 6%,15%,and 24%,respectively.Overall,more than half of the targeted pharmaceuticals showed significant average removal(>60%),highlighting the influence of the processes involved in groundwater on the natural attenuation of these compounds.Sorption seemed to be the primary process contributing to the target pharmaceuticals attenuation in oxic conditions,while biodegradation played a secondary role,particularly for atenolol and metoprolol.These findings contribute to improve our understanding of the behaviour of pharmaceuticals in aquatic environment and thus to improve management practices for better water quality.
