In China′s Loess Plateau area, gully head is the most active zone of a drainage system in gully areas. The differentiation of loess gully head follows geospatial patterns and reflects the process of the loess landfor...In China′s Loess Plateau area, gully head is the most active zone of a drainage system in gully areas. The differentiation of loess gully head follows geospatial patterns and reflects the process of the loess landform development and evolution of its drainage system to some extent. In this study, the geomorphic meaning, basic characteristics, morphological structure and the basic types of loess gully heads were systematically analysed. Then, the loess gully head′s conceptual model was established, and an extraction method based on Digital Elevation Model(DEM) for loess gully head features and elements was proposed. Through analysing the achieved statistics of loess gully head features, loess gully heads have apparently similar and different characteristics depending on the different loess landforms where they are found. The loess head characteristics reflect their growth period and evolution tendency to a certain degree, and they indirectly represent evolutionary mechanisms. In addition, the loess gully developmental stages and the evolutionary processes can be deduced by using loess gully head characteristics. This study is of great significance for development and improvement of the theoretical system for describing loess gully landforms.展开更多
Based on the survey of international emissions trading system （ETS） and quantitative analysis, policy suggestions on establishing a carbon ETS in China are presented in this study. Sectors sensitive to carbon prices...Based on the survey of international emissions trading system （ETS） and quantitative analysis, policy suggestions on establishing a carbon ETS in China are presented in this study. Sectors sensitive to carbon prices, e.g., the power generation sector and the iron and steel industry, are given priority to be covered by the ETS. Interregional carbon trading should be carried out as early as possible. The cap of the ETS should be based on China＇s carbon intensity reduction target with the floor carbon price for the market being set in the beginning. Suggestions on the infrastructure of ETS are also proposed, including the national wide carbon measuring, reporting, verification system building. account registration system and the legislation to national展开更多
In recent years the demand for the acoustic performance of exhaust systems has increased and will further increase in the future. The main drivers are new pass-by-noise regulation and new powertrain technologies paire...In recent years the demand for the acoustic performance of exhaust systems has increased and will further increase in the future. The main drivers are new pass-by-noise regulation and new powertrain technologies paired with exhaust muffler volume, weight and costs constraints. In the following paper several application examples for Adaptive ValveTM （self-actuated in-pipe valve）, in-muffler valve and electric valve are shown and the related benefits on the system performance are assessed. It is shown that implementing a valve into an exhaust system has a significant influence on the NVH performance. The resulting backpressure penalties can be minimized using the right implementation strategy of the valves in the exhaust system. Hence the exhaust system has to be specifically designed for the integration of a valve. All three valve types have additional benefits to their standard application for overall noise reduction and muffler volume reduction, which are analyzed. The Adaptive ValveTM, for example, is often used on cars with long pipe routing and has the additional benefit of reducing pipe resonance in the system. Another example, the electric valve, can be coupled with vehicle communication networks and hence the flexibility in application is significantly increased.展开更多
The reasons of introducing cold air into pulverizer are analyzed for boilers with large capacity and high parameters. The temperature rises of the exhaust gas are calculated when varying the amount of the cold air. Th...The reasons of introducing cold air into pulverizer are analyzed for boilers with large capacity and high parameters. The temperature rises of the exhaust gas are calculated when varying the amount of the cold air. The hot primary air heater, a new technology, is developed to eliminate the cold air from the pulverized coal system. The applications, advantages and disadvantages are introduced in detail for the new device and system. It is concluded that introducing cold air into pulverizer is one of the major factors that causes the exhaust gas temperature of boilers with large capacity to be high. The amount of the cold air could be reduced signif icantly, even to zero in some cases by adopting the hot primary air heater, which drops the exhaust gas temperature of the boiler effectively. The hot primary air heater, which could play part roles of the steam-air heater or the hot air recirculation system, could also be used to adjust the exhaust gas temperature within the range of 20 ℃ by controlling the flow rate of the cooling medium. Moreover, the startup period of the steam-air heater or the hot air recirculation system will be shortened, which is a unique advantage of the hot primary air heater among the measures to drop the exhaust gas temperature.展开更多
Between the alternative sources available for the electricity production, still lacks reliability for the production in base units. For the electricity production from 500 MW to 1,000 MW or more, the coal-fired therma...Between the alternative sources available for the electricity production, still lacks reliability for the production in base units. For the electricity production from 500 MW to 1,000 MW or more, the coal-fired thermal and nuclear power plants with uranium have proved competitive and with a high level of reliability and maturation, besides presenting the fuel supply security. This paper presents an analysis of technical feasibility for the choice of the best technology for generating electricity on a large scale, based on coal-fired thermal or nuclear power plant using uranium. This paper takes in account the availability of fuel sources, investments costs, thermal power generation systems, pollutants emission and mitigation technologies, global efficiency, fuel consumption, costs of electricity, construction time and an average lifespan of the installation. Thus the analysis allows the most rational choice of technology for the production of electricity with lower electricity costs and lower COz emissions.展开更多
An electricity generation planning model of the six major Chinese power grids was developed based on the General Algebraic Modeling System to evaluate and analyze the CDM （clean development mechanism）, including con...An electricity generation planning model of the six major Chinese power grids was developed based on the General Algebraic Modeling System to evaluate and analyze the CDM （clean development mechanism）, including consideration of the environmental co-benefits of reductions in air pollutants （SO~, NO~ and particulate matter） achieved by advanced electricity generation technologies incorporating CCS （carbon capture and storage）. An objective function was developed that included revenue from sales of electric power, total system cost, the cost of CO2 transport and storage, and emissions reduction co-benefits for SOx, NO~, and particulate matter. The objective function was minimized using an optimization model. We also developed a method for evaluating and analyzing the potential for transferring advanced power generation technologies into the Chinese power system through the CDM. We found that： （1） thermal power generation is predominant in the Chinese electricity system and will remain so for a long time; （2） advanced thermal plants are being installed as a result of the CDM, which contribute to decreasing emissions of CO2 and other air pollutants; and （3） CCS projects have significant potential to reduce substantial and sustained CO2 emissions from the Chinese power and industrial sectors.展开更多
Energy conversion and utilization, particularly carbon-based fuel burning in air phase, have caused great environmental pollution and serious problems to society. The reactions in water phase may have the potential to...Energy conversion and utilization, particularly carbon-based fuel burning in air phase, have caused great environmental pollution and serious problems to society. The reactions in water phase may have the potential to realize clean and efficient energy conversion and utilization. Coal gasification in supercritical water is a typical carbon-based fuel conversion process in water phase, and it takes the advantages of the unique chemical and physical properties of supercritical water to convert organic matter in coal to H2 and CO2. N, S, P, Hg and other elements are deposited as inorganic salts to avoid pollution emission. The State Key Laboratory of Multiphase Flow in Power Engineering has obtained extensive experimental and theoretical results based on coal gasification in supercritical water. Supercritical water fluidized bed reactor was developed for coal gasification and seven kinds of typical feedstock were selected. The hydrogen yield covers from 0.67 to 1.74 Nm3/kg and the carbon gasification efficiency is no less than 97%. This technology has a bright future in industrialization not only in electricity generation but also in hydrogen production and high value-added chemicals. Given the gas yield obtained in laboratory-scale unit, the hydrogen production cost is U.S.$ 0.111 Nm3 when the throughput capacity is 2000 t/d. A novel thermodynamic cycle power generation system based on coal gasification in supercritical water was proposed with the obvious advantages of high coal-electricity conversion efficiency and zero pollutant emission. The cost of U.S.$ 3.69 billion for desulfuration, denitration and dust removal in China in 2013 would have been saved with this technology. Five kinds of heat supply methods are analyzed and the rates of return of investment are roughly estimated. An integrated cooperative innovation center called a new type of high-efficient coal gasification technology and its large-scale utilization was founded to enhance the industrialization of the technology vigorously.展开更多
We verified that the matrix method, a process analysis method used mainly for life cycle inventory analysis, has several advantages in the analysis of power systems, which have recently become more complex to enhance ...We verified that the matrix method, a process analysis method used mainly for life cycle inventory analysis, has several advantages in the analysis of power systems, which have recently become more complex to enhance efficiency and to reduce C02 emissions. While designing a conceptual thermodynamic model of a complex power system, the matrix method provides a definite procedure and facilitates calculations, even if there is a recttrsive loop between the upstream and downstream processes. Similarly, in the case of partial modification to the constructed model, the matrix method can potentially reduce the time and effort required to calculate the thermodynamic balances, even if the constructed model is designed by others. In this study, we obtained mass flow and energy balances of example model power systems by the matrix method from the common thermodynamic conditions including temperatures and pressures which are set on the basis of an existing industrial steam power system. While analyzing the environmental impact of complex multiproduct power systems, such as carbon emissions, the matrix method can be used to easily derive the environmental impact of each final product. We could verify the efficacy of the matrix method in accurately deriving that of an example model power system.展开更多
The complete sequence of the mitochondrial genome of the Japanese snapping shrimp Alpheus japonicus Miers （Crustacea： Decapoda： Caridea） is presented here. A comparative analysis based on the currently available m...The complete sequence of the mitochondrial genome of the Japanese snapping shrimp Alpheus japonicus Miers （Crustacea： Decapoda： Caridea） is presented here. A comparative analysis based on the currently available mitochondrial genomic data re- vealed many previously unknown characteristics of the mitochondrial genomes of caridean shrimps. The A. japonicus mito- chondrial genome is 16487 bp long and contains the typical set of 37 metazoan genes. The gene arrangements in the mito- chondrial genomes of four previously studied carideans （Macrobrachium rosenbergii, M. nipponense, M. lanchesteri and Halocaridina rubra） were found to be identical to the pancrustacean ground pattern; thus, it was considered that gene rear- rangements probably did not occur in the suborder Caridea. In the present study, a translocation of the trnE gene involving in- version was found in Alpheus mitochondrial genomes. This phenomenon has not been reported in any other crustacean mito- chondrial genome that has been studied so far; however, the translocation of one transfer RNA gene （trnP or trnT） was report- ed in the mitochondrial genome of Exopalaemon carinicauda. When the ratios of the nonsynonymous and synonymous sub- stitutions rates （Ka/Ks） for the 13 protein coding genes from two Alpheus species （A. japonicus and A. distinguendus） and three Macrobrachium species （M. rosenbergii, M. nipponense, M. lanchesteri） were calculated, the KaIKs values for all the protein coding genes in Alpheus and Macrobrachium mitochondrial genomes were found to be less than 1 （between 0.0048 and 0.2057）, indicating that a strong purification selection had occurred. The phylogenetic tree that was constructed based on the mitochondrial protein coding genes in the genomes of nine related species indicated that Palaemonidae and Alpheidae formed a monophyly and shared a statistically significant relationship, （Palaemonidae＋Alpheidae）＋Atyidae, at the family level.展开更多
基金Under the auspices of National Youth Science Foundation of China(No.41001294)Key Project of National Natural Science Foundation of China(No.40930531)Research Fund of State Key Laboratory Resources and Environment Information System(No.2010KF0002SA)
文摘In China′s Loess Plateau area, gully head is the most active zone of a drainage system in gully areas. The differentiation of loess gully head follows geospatial patterns and reflects the process of the loess landform development and evolution of its drainage system to some extent. In this study, the geomorphic meaning, basic characteristics, morphological structure and the basic types of loess gully heads were systematically analysed. Then, the loess gully head′s conceptual model was established, and an extraction method based on Digital Elevation Model(DEM) for loess gully head features and elements was proposed. Through analysing the achieved statistics of loess gully head features, loess gully heads have apparently similar and different characteristics depending on the different loess landforms where they are found. The loess head characteristics reflect their growth period and evolution tendency to a certain degree, and they indirectly represent evolutionary mechanisms. In addition, the loess gully developmental stages and the evolutionary processes can be deduced by using loess gully head characteristics. This study is of great significance for development and improvement of the theoretical system for describing loess gully landforms.
基金supported by the National Basic Research Program of China(No.2012CB955700 and 2010CB955501)
文摘Based on the survey of international emissions trading system （ETS） and quantitative analysis, policy suggestions on establishing a carbon ETS in China are presented in this study. Sectors sensitive to carbon prices, e.g., the power generation sector and the iron and steel industry, are given priority to be covered by the ETS. Interregional carbon trading should be carried out as early as possible. The cap of the ETS should be based on China＇s carbon intensity reduction target with the floor carbon price for the market being set in the beginning. Suggestions on the infrastructure of ETS are also proposed, including the national wide carbon measuring, reporting, verification system building. account registration system and the legislation to national
文摘In recent years the demand for the acoustic performance of exhaust systems has increased and will further increase in the future. The main drivers are new pass-by-noise regulation and new powertrain technologies paired with exhaust muffler volume, weight and costs constraints. In the following paper several application examples for Adaptive ValveTM （self-actuated in-pipe valve）, in-muffler valve and electric valve are shown and the related benefits on the system performance are assessed. It is shown that implementing a valve into an exhaust system has a significant influence on the NVH performance. The resulting backpressure penalties can be minimized using the right implementation strategy of the valves in the exhaust system. Hence the exhaust system has to be specifically designed for the integration of a valve. All three valve types have additional benefits to their standard application for overall noise reduction and muffler volume reduction, which are analyzed. The Adaptive ValveTM, for example, is often used on cars with long pipe routing and has the additional benefit of reducing pipe resonance in the system. Another example, the electric valve, can be coupled with vehicle communication networks and hence the flexibility in application is significantly increased.
文摘The reasons of introducing cold air into pulverizer are analyzed for boilers with large capacity and high parameters. The temperature rises of the exhaust gas are calculated when varying the amount of the cold air. The hot primary air heater, a new technology, is developed to eliminate the cold air from the pulverized coal system. The applications, advantages and disadvantages are introduced in detail for the new device and system. It is concluded that introducing cold air into pulverizer is one of the major factors that causes the exhaust gas temperature of boilers with large capacity to be high. The amount of the cold air could be reduced signif icantly, even to zero in some cases by adopting the hot primary air heater, which drops the exhaust gas temperature of the boiler effectively. The hot primary air heater, which could play part roles of the steam-air heater or the hot air recirculation system, could also be used to adjust the exhaust gas temperature within the range of 20 ℃ by controlling the flow rate of the cooling medium. Moreover, the startup period of the steam-air heater or the hot air recirculation system will be shortened, which is a unique advantage of the hot primary air heater among the measures to drop the exhaust gas temperature.
文摘Between the alternative sources available for the electricity production, still lacks reliability for the production in base units. For the electricity production from 500 MW to 1,000 MW or more, the coal-fired thermal and nuclear power plants with uranium have proved competitive and with a high level of reliability and maturation, besides presenting the fuel supply security. This paper presents an analysis of technical feasibility for the choice of the best technology for generating electricity on a large scale, based on coal-fired thermal or nuclear power plant using uranium. This paper takes in account the availability of fuel sources, investments costs, thermal power generation systems, pollutants emission and mitigation technologies, global efficiency, fuel consumption, costs of electricity, construction time and an average lifespan of the installation. Thus the analysis allows the most rational choice of technology for the production of electricity with lower electricity costs and lower COz emissions.
文摘An electricity generation planning model of the six major Chinese power grids was developed based on the General Algebraic Modeling System to evaluate and analyze the CDM （clean development mechanism）, including consideration of the environmental co-benefits of reductions in air pollutants （SO~, NO~ and particulate matter） achieved by advanced electricity generation technologies incorporating CCS （carbon capture and storage）. An objective function was developed that included revenue from sales of electric power, total system cost, the cost of CO2 transport and storage, and emissions reduction co-benefits for SOx, NO~, and particulate matter. The objective function was minimized using an optimization model. We also developed a method for evaluating and analyzing the potential for transferring advanced power generation technologies into the Chinese power system through the CDM. We found that： （1） thermal power generation is predominant in the Chinese electricity system and will remain so for a long time; （2） advanced thermal plants are being installed as a result of the CDM, which contribute to decreasing emissions of CO2 and other air pollutants; and （3） CCS projects have significant potential to reduce substantial and sustained CO2 emissions from the Chinese power and industrial sectors.
基金supported by the National Natural Science Foundation of China(Grant Nos.5132301151306145&51236007)
文摘Energy conversion and utilization, particularly carbon-based fuel burning in air phase, have caused great environmental pollution and serious problems to society. The reactions in water phase may have the potential to realize clean and efficient energy conversion and utilization. Coal gasification in supercritical water is a typical carbon-based fuel conversion process in water phase, and it takes the advantages of the unique chemical and physical properties of supercritical water to convert organic matter in coal to H2 and CO2. N, S, P, Hg and other elements are deposited as inorganic salts to avoid pollution emission. The State Key Laboratory of Multiphase Flow in Power Engineering has obtained extensive experimental and theoretical results based on coal gasification in supercritical water. Supercritical water fluidized bed reactor was developed for coal gasification and seven kinds of typical feedstock were selected. The hydrogen yield covers from 0.67 to 1.74 Nm3/kg and the carbon gasification efficiency is no less than 97%. This technology has a bright future in industrialization not only in electricity generation but also in hydrogen production and high value-added chemicals. Given the gas yield obtained in laboratory-scale unit, the hydrogen production cost is U.S.$ 0.111 Nm3 when the throughput capacity is 2000 t/d. A novel thermodynamic cycle power generation system based on coal gasification in supercritical water was proposed with the obvious advantages of high coal-electricity conversion efficiency and zero pollutant emission. The cost of U.S.$ 3.69 billion for desulfuration, denitration and dust removal in China in 2013 would have been saved with this technology. Five kinds of heat supply methods are analyzed and the rates of return of investment are roughly estimated. An integrated cooperative innovation center called a new type of high-efficient coal gasification technology and its large-scale utilization was founded to enhance the industrialization of the technology vigorously.
文摘We verified that the matrix method, a process analysis method used mainly for life cycle inventory analysis, has several advantages in the analysis of power systems, which have recently become more complex to enhance efficiency and to reduce C02 emissions. While designing a conceptual thermodynamic model of a complex power system, the matrix method provides a definite procedure and facilitates calculations, even if there is a recttrsive loop between the upstream and downstream processes. Similarly, in the case of partial modification to the constructed model, the matrix method can potentially reduce the time and effort required to calculate the thermodynamic balances, even if the constructed model is designed by others. In this study, we obtained mass flow and energy balances of example model power systems by the matrix method from the common thermodynamic conditions including temperatures and pressures which are set on the basis of an existing industrial steam power system. While analyzing the environmental impact of complex multiproduct power systems, such as carbon emissions, the matrix method can be used to easily derive the environmental impact of each final product. We could verify the efficacy of the matrix method in accurately deriving that of an example model power system.
基金supported by the National Natural Science Foundation of China (Grant Nos. 40906067 and 31172054)Special Funds From the Central Finance to Support the Development of Local Universities(Grant No. CXTD04)+1 种基金the China Postdoctoral Science Foundation Funded Project (Grant No. 2012M510054)the Jiangsu Key Laboratory of Marine Biotechnology (Grant Nos. 2009HS12 and 2009HS13)
文摘The complete sequence of the mitochondrial genome of the Japanese snapping shrimp Alpheus japonicus Miers （Crustacea： Decapoda： Caridea） is presented here. A comparative analysis based on the currently available mitochondrial genomic data re- vealed many previously unknown characteristics of the mitochondrial genomes of caridean shrimps. The A. japonicus mito- chondrial genome is 16487 bp long and contains the typical set of 37 metazoan genes. The gene arrangements in the mito- chondrial genomes of four previously studied carideans （Macrobrachium rosenbergii, M. nipponense, M. lanchesteri and Halocaridina rubra） were found to be identical to the pancrustacean ground pattern; thus, it was considered that gene rear- rangements probably did not occur in the suborder Caridea. In the present study, a translocation of the trnE gene involving in- version was found in Alpheus mitochondrial genomes. This phenomenon has not been reported in any other crustacean mito- chondrial genome that has been studied so far; however, the translocation of one transfer RNA gene （trnP or trnT） was report- ed in the mitochondrial genome of Exopalaemon carinicauda. When the ratios of the nonsynonymous and synonymous sub- stitutions rates （Ka/Ks） for the 13 protein coding genes from two Alpheus species （A. japonicus and A. distinguendus） and three Macrobrachium species （M. rosenbergii, M. nipponense, M. lanchesteri） were calculated, the KaIKs values for all the protein coding genes in Alpheus and Macrobrachium mitochondrial genomes were found to be less than 1 （between 0.0048 and 0.2057）, indicating that a strong purification selection had occurred. The phylogenetic tree that was constructed based on the mitochondrial protein coding genes in the genomes of nine related species indicated that Palaemonidae and Alpheidae formed a monophyly and shared a statistically significant relationship, （Palaemonidae＋Alpheidae）＋Atyidae, at the family level.
