For acquiring the details in aluminum holding furnace with bottom porous brick purging system,efforts were performed to try to find out the potential optimal operation schemes.By adopting transient analysis scheme and...For acquiring the details in aluminum holding furnace with bottom porous brick purging system,efforts were performed to try to find out the potential optimal operation schemes.By adopting transient analysis scheme and constant boundary temperature,combustion in the furnace was investigated numerically using computational fluid dynamics(CFD).The predicted gas temperature shows good agreement with the measured results,and the predicted energy distribution of the furnace is consistent with that obtained from energy balance experiment,which confirms the reliability of the numerical solution.The results show that as the fuel-air mixture temperature rises up from 300 K to 500 K,the energy utilization of the furnace could increase from 34.55% to 37.14%.However,as the excess air coefficient increases from 1.0 to 1.4,energy utilization drops from 34.55% to 29.56%.Increasing the combustion temperature is the most effective way to improve the energy efficiency of the furnace.High reactant temperature and medium excess air coefficient are recommended for high operation performance,and keeping the furnace jamb sealed well for avoiding leakage has to be emphasized.展开更多
The effects of root oxidization ability and P fertilization on As mobility in soils, and subsequently As uptake, translocation and speciation in rice plants were investigated. Results show that root oxidation signific...The effects of root oxidization ability and P fertilization on As mobility in soils, and subsequently As uptake, translocation and speciation in rice plants were investigated. Results show that root oxidation significantly influences As mobility in rhizoshphere.Genotype TD71 with higher radial oxygen loss(ROL) induces more Fe plaque formation and sequesters more As and P in iron plaque and rhizoshphere soil, leading to the reduction of As accumulation in rice plants. Additionally, P addition mobilizes As in soil solution, and increases As accumulation in rice plants. Arsenic speciation results show that the majority of As species in husks detected is inorganic As, accounting for 82%-93% of the total As, while in grains the majority of As is inorganic As and dimethyl arsenic(DMA), with DMA accounting for 33%-64% of the total As. The fraction of inorganic As decreases while fraction of DMA increases, with increasing As and P concentrations. The study further elucidates the mechanisms involved in effects of ROL on As tolerance and accumulation in rice.展开更多
The taxi drivers' cruising pattern was learned using GPS trajectory data collected in Shenzhen,China.By employing zero-inflated Poisson model,the impacts of land use and previous pick-up experience on cruising dec...The taxi drivers' cruising pattern was learned using GPS trajectory data collected in Shenzhen,China.By employing zero-inflated Poisson model,the impacts of land use and previous pick-up experience on cruising decision were measured.The cruising strategies of different types of drivers as well as the top one driver were examined.The results indicate that both land use and previous pick-up experience affect travel behavior with the former's influence(7.07×10-4 measured by one of the coefficients in zero-inflated Poisson model) being greater than the latter's(4.58×10-5) in general,but the comparison also varies across the types of drivers.Besides,taxi drivers' day-to-day learning feature is also proved by the results.According to comparison of the cruising behavior of the most efficient and inefficient driver,an efficient cruising strategy was proposed,that is,obeying the distribution of land use in choice of cruising area,while learning from pick-up experience in selection of detailed cruising location.By learning taxi drivers' cruising pattern,the development of measures of regulating travel behaviors is facilitated,important factor for traffic organization and planning is identified,and an efficient cruising strategy for taxi drivers is provided.展开更多
Energy and environmental sustainability are important considerations for increased rice production. This study examined the energy utilization and sustainability of rice processing in sub-Saharan Africa. The community...Energy and environmental sustainability are important considerations for increased rice production. This study examined the energy utilization and sustainability of rice processing in sub-Saharan Africa. The community of Gadan Loko village in the song local government of Adamawa State, Nigeria was selected as the focus of study. Rice parboiling, the most energy intensive process in rice processing is carried out usually by women in small quantities of about 13.2 kg using traditional pots on tripod support stoves. The parboiled rice is sun dried on mats before it is taken to the milling stalls where it is milled using milling machines driven by single cylinder diesel engines. There were large variations in the quality of milled rice due to lack of consistency in processing parameters. Accumulation of rice husk in the community created important environmental issues. In this study, methods of improving sustainability of rice processing were investigated. The areas included: the utilization of waste heat from the diesel engines for improved drying and efficient pre-soaking; the utilization of solar energy for pre-soaking; the utilization of rice husks as alternative fuel to firewood; and the optimization and redesign of the stoves and parboiling vessels to minimize heat loss to the environment. The results showed that the utilization of rice husk as alternative fuel and the redesign of the stoves and parboiling vessels will increase the sustainability of rice processing and can be easily adopted by the community. While solar energy pre-soaking was not economical and the utilization of waste heat from the diesel engines for drying and pre-soaking would be difficult to implement at the rural scale, because most of the parboiling is done far away from the milling stalls. The study showed that research, development of appropriate technology, and education (RATE) of the rural community is an important way of increasing sustainability.展开更多
Using the new formula of moist available energy (MAE), the value of the MAE’s key terms ofthree heavy rainfall cases in Guangdong province in 1998 was calculated. The energetic aggregation andenergetic discharge are ...Using the new formula of moist available energy (MAE), the value of the MAE’s key terms ofthree heavy rainfall cases in Guangdong province in 1998 was calculated. The energetic aggregation andenergetic discharge are analyzed. It shows that the value of the key terms in the formula appears different featureclearly in the different precipitation period, as well as the function of each term presents in the heavy rain region.展开更多
Coals are carbon-rich materials with excellent aromatic nature and macro- molecular structure. They pose great potential as the source of organic chemical feed- stock and high value-added carbonaceous materials in the...Coals are carbon-rich materials with excellent aromatic nature and macro- molecular structure. They pose great potential as the source of organic chemical feed- stock and high value-added carbonaceous materials in the 21st century. As some of the most important analytical methods, thermal analysis (TA) techniques with strong com- petence in materials characterization and reaction mechanism research, have been ex- tensively employed to accumulate the knowledge about coal conversion and utilization in a most effective, efficient and responsible way. Unfortunately, some efforts did not promote the sound growth of a systematic discipline, which might arise from the intrinsic drawback of conventional TA. Proposals on acquiring much more reliable understanding of the mechanism and kinetics of reactions were made in this review.展开更多
The present paper seeks to investigate the extent to which digital activism plays a role in political activism in Morocco through the intersection between women and young activists movement and the social media. By do...The present paper seeks to investigate the extent to which digital activism plays a role in political activism in Morocco through the intersection between women and young activists movement and the social media. By doing so the author argues that while facebook and the Moroccan political arena are Male dominated public areas, young female activists have emerged as prominent leaders in both spaces. The author will more particularly explain why female and youth activists are important in the current state of Moroccan politics. Next, the author provides a discussion of the February 20th Movement, and the movement's utilization of Facebook. It will show that young female activists involved in the February 20th Movement have used Facebook in unique and creative ways to further the Movement.展开更多
This paper briefly introduces the application of new materials in sports and effect on sports performance, points out that development of competitive sports in the process, must pay attention to the development and ut...This paper briefly introduces the application of new materials in sports and effect on sports performance, points out that development of competitive sports in the process, must pay attention to the development and utilization of new materials, development.展开更多
In the past two decades,dynamic covalent chemistry has been greatly developed,which is mainly reflected in two aspects:1.new dynamic covalent bonds(DCBs)are continuously discovered;2.various DCBs have been introduced ...In the past two decades,dynamic covalent chemistry has been greatly developed,which is mainly reflected in two aspects:1.new dynamic covalent bonds(DCBs)are continuously discovered;2.various DCBs have been introduced into polymer materials for different functions.These functional polymer materials have brought new opportunities for sustainable development.In this review,we provide an overview of various functions endowed by DCBs in polymer materials,including self-healing,chemical recycling,and shape controlling.Particularly,we pay much attention to the three-dimensional(3D)shape reconfiguration/programming,surface patterning,and reversible actuation.In addition,we also give the current issues,challenges,and opportunities on DCBs-containing materials and point out its developing directions in the future.展开更多
基金Project(2009GK2009) supported by the Science and Technology Program of Hunan Province,China
文摘For acquiring the details in aluminum holding furnace with bottom porous brick purging system,efforts were performed to try to find out the potential optimal operation schemes.By adopting transient analysis scheme and constant boundary temperature,combustion in the furnace was investigated numerically using computational fluid dynamics(CFD).The predicted gas temperature shows good agreement with the measured results,and the predicted energy distribution of the furnace is consistent with that obtained from energy balance experiment,which confirms the reliability of the numerical solution.The results show that as the fuel-air mixture temperature rises up from 300 K to 500 K,the energy utilization of the furnace could increase from 34.55% to 37.14%.However,as the excess air coefficient increases from 1.0 to 1.4,energy utilization drops from 34.55% to 29.56%.Increasing the combustion temperature is the most effective way to improve the energy efficiency of the furnace.High reactant temperature and medium excess air coefficient are recommended for high operation performance,and keeping the furnace jamb sealed well for avoiding leakage has to be emphasized.
基金Project(41201493)supported by the National Natural Science Foundation of ChinaProject(201109056)supported by Special Scientific Research of Environmental Protection for Public Welfare Industry,China
文摘The effects of root oxidization ability and P fertilization on As mobility in soils, and subsequently As uptake, translocation and speciation in rice plants were investigated. Results show that root oxidation significantly influences As mobility in rhizoshphere.Genotype TD71 with higher radial oxygen loss(ROL) induces more Fe plaque formation and sequesters more As and P in iron plaque and rhizoshphere soil, leading to the reduction of As accumulation in rice plants. Additionally, P addition mobilizes As in soil solution, and increases As accumulation in rice plants. Arsenic speciation results show that the majority of As species in husks detected is inorganic As, accounting for 82%-93% of the total As, while in grains the majority of As is inorganic As and dimethyl arsenic(DMA), with DMA accounting for 33%-64% of the total As. The fraction of inorganic As decreases while fraction of DMA increases, with increasing As and P concentrations. The study further elucidates the mechanisms involved in effects of ROL on As tolerance and accumulation in rice.
基金Project(50908099)supported by the National Natural Science Foundation of ChinaProject(201104493)supported by the Doctoral Program of Higher Education of China
文摘The taxi drivers' cruising pattern was learned using GPS trajectory data collected in Shenzhen,China.By employing zero-inflated Poisson model,the impacts of land use and previous pick-up experience on cruising decision were measured.The cruising strategies of different types of drivers as well as the top one driver were examined.The results indicate that both land use and previous pick-up experience affect travel behavior with the former's influence(7.07×10-4 measured by one of the coefficients in zero-inflated Poisson model) being greater than the latter's(4.58×10-5) in general,but the comparison also varies across the types of drivers.Besides,taxi drivers' day-to-day learning feature is also proved by the results.According to comparison of the cruising behavior of the most efficient and inefficient driver,an efficient cruising strategy was proposed,that is,obeying the distribution of land use in choice of cruising area,while learning from pick-up experience in selection of detailed cruising location.By learning taxi drivers' cruising pattern,the development of measures of regulating travel behaviors is facilitated,important factor for traffic organization and planning is identified,and an efficient cruising strategy for taxi drivers is provided.
文摘Energy and environmental sustainability are important considerations for increased rice production. This study examined the energy utilization and sustainability of rice processing in sub-Saharan Africa. The community of Gadan Loko village in the song local government of Adamawa State, Nigeria was selected as the focus of study. Rice parboiling, the most energy intensive process in rice processing is carried out usually by women in small quantities of about 13.2 kg using traditional pots on tripod support stoves. The parboiled rice is sun dried on mats before it is taken to the milling stalls where it is milled using milling machines driven by single cylinder diesel engines. There were large variations in the quality of milled rice due to lack of consistency in processing parameters. Accumulation of rice husk in the community created important environmental issues. In this study, methods of improving sustainability of rice processing were investigated. The areas included: the utilization of waste heat from the diesel engines for improved drying and efficient pre-soaking; the utilization of solar energy for pre-soaking; the utilization of rice husks as alternative fuel to firewood; and the optimization and redesign of the stoves and parboiling vessels to minimize heat loss to the environment. The results showed that the utilization of rice husk as alternative fuel and the redesign of the stoves and parboiling vessels will increase the sustainability of rice processing and can be easily adopted by the community. While solar energy pre-soaking was not economical and the utilization of waste heat from the diesel engines for drying and pre-soaking would be difficult to implement at the rural scale, because most of the parboiling is done far away from the milling stalls. The study showed that research, development of appropriate technology, and education (RATE) of the rural community is an important way of increasing sustainability.
基金Dedicated Research Fund for Public Interest from the Ministry of Science andTechnology(2002DIA20013)"973" Key Project from the Ministry of Science and Technology (2004CB418305)
文摘Using the new formula of moist available energy (MAE), the value of the MAE’s key terms ofthree heavy rainfall cases in Guangdong province in 1998 was calculated. The energetic aggregation andenergetic discharge are analyzed. It shows that the value of the key terms in the formula appears different featureclearly in the different precipitation period, as well as the function of each term presents in the heavy rain region.
文摘Coals are carbon-rich materials with excellent aromatic nature and macro- molecular structure. They pose great potential as the source of organic chemical feed- stock and high value-added carbonaceous materials in the 21st century. As some of the most important analytical methods, thermal analysis (TA) techniques with strong com- petence in materials characterization and reaction mechanism research, have been ex- tensively employed to accumulate the knowledge about coal conversion and utilization in a most effective, efficient and responsible way. Unfortunately, some efforts did not promote the sound growth of a systematic discipline, which might arise from the intrinsic drawback of conventional TA. Proposals on acquiring much more reliable understanding of the mechanism and kinetics of reactions were made in this review.
文摘The present paper seeks to investigate the extent to which digital activism plays a role in political activism in Morocco through the intersection between women and young activists movement and the social media. By doing so the author argues that while facebook and the Moroccan political arena are Male dominated public areas, young female activists have emerged as prominent leaders in both spaces. The author will more particularly explain why female and youth activists are important in the current state of Moroccan politics. Next, the author provides a discussion of the February 20th Movement, and the movement's utilization of Facebook. It will show that young female activists involved in the February 20th Movement have used Facebook in unique and creative ways to further the Movement.
文摘This paper briefly introduces the application of new materials in sports and effect on sports performance, points out that development of competitive sports in the process, must pay attention to the development and utilization of new materials, development.
基金financially supported by the National Natural Science Foundation of China(21734006)the Foundation for Innovative Research Group of the National Natural Science Foundation of China(21821001)。
文摘In the past two decades,dynamic covalent chemistry has been greatly developed,which is mainly reflected in two aspects:1.new dynamic covalent bonds(DCBs)are continuously discovered;2.various DCBs have been introduced into polymer materials for different functions.These functional polymer materials have brought new opportunities for sustainable development.In this review,we provide an overview of various functions endowed by DCBs in polymer materials,including self-healing,chemical recycling,and shape controlling.Particularly,we pay much attention to the three-dimensional(3D)shape reconfiguration/programming,surface patterning,and reversible actuation.In addition,we also give the current issues,challenges,and opportunities on DCBs-containing materials and point out its developing directions in the future.