Targeting the problem of large amounts of gas emission from the goaf of the No.14201 working face in the Shaqu coal mine of Huajin Coking Coal Co. Ltd., we used a negative exponential function to describe the attenuat...Targeting the problem of large amounts of gas emission from the goaf of the No.14201 working face in the Shaqu coal mine of Huajin Coking Coal Co. Ltd., we used a negative exponential function to describe the attenuation process of gas emission in goaf (the stable source) based on the principle of field flow. Equations of two-component flow (gas and air) and seep- age-diffusion in a heterogeneous goaf flow field are solved by means of numerical simulation and fluid mechanics principles of air movement and gas distribution during gas emission from goaf. The results indicate that the air diversion volume has a negative, exponential relation with the volume of gas emitted from goaf to the working face and is clearly inversely related to gas concentra- tion. We calculated the minimum amount of air diversion and distributed air volume in the tailing roadway required for safe pro- duction.展开更多
In this article, the authors propose the production of ethanol from cellulose as an alternative to oil. Cellulosic-ethanol will reduce greenhouse gas emissions, and provide a means to prevent forest fires. This liquid...In this article, the authors propose the production of ethanol from cellulose as an alternative to oil. Cellulosic-ethanol will reduce greenhouse gas emissions, and provide a means to prevent forest fires. This liquid dense fuel was selected because it： （1） easily transported and dispensed as a fuel; （2） can be handled by the existing fuel distribution infrastructure; and （3） unlike its commercial competitor, Me-OH （Methanol）, Et-OH （Ethanol）, is edible, thus being biodegradable and nontoxic. Forest residue ethanol is cheaper to produce and more environmentally friendly than other forms of ethanol fuel. Furthermore, forests would have less available ground fuel for fires. The potential decline of forest fires would then reduce the carbon footprint attributed directly to forest fires. In combination with ethanol fuel combustion, carbon emissions can be reduced by more than 70% compared to gasoline combustion. We used GREET （Greenhouse gases, Regulated Emissions, and Energy use in Transportation） software to assess the life cycles of different fuel pathways. In conclusion, cellulosic ethanol fuel is clearly an answer to decrease dependency on current oil imports and prevent forest fires.展开更多
Rice paddies are increasingly being converted to vegetable production due to economic benefits related,in part,to changes in demand during recent decades.Here,we implemented a parallel field experiment to simultaneous...Rice paddies are increasingly being converted to vegetable production due to economic benefits related,in part,to changes in demand during recent decades.Here,we implemented a parallel field experiment to simultaneously measure annual emissions of CH_4and N_2O,and soil organic carbon(SOC)stock changes,in rice paddies(RP),rice paddy–converted conventional vegetable fields(CV),and rice paddy–converted greenhouse vegetable fields(GV).Changing from rice to vegetable production reduced CH_4emissions by nearly 100%,and also triggered substantial N_2O emissions.Furthermore,annual N_2O emissions from GV significantly exceeded those from CV due to lower soil p H and higher soil temperature.Marginal SOC losses occurred after one year of cultivation of RP,CV,and GV,contributing an important share(3.4%,32.2%,and 10.3%,respectively)of the overall global warming potential(GWP)balance.The decline in CH_4emissions outweighed the increased N_2O emissions and SOC losses in CV and GV,leading to a 13%–30%reduction in annual GWP as compared to RP.These results suggest that large-scale expansion of vegetable production at the expense of rice paddies is beneficial for mitigating climate change in terms of the overall GWP.展开更多
Soil samples were taken from an Ermans birch （Betula ermanii）-dark coniferous forest （Picea jezoensis and Abies nephrolepis） ecotone growing on volcanic ejecta in the northern slope of Changbai Mountains of Northe...Soil samples were taken from an Ermans birch （Betula ermanii）-dark coniferous forest （Picea jezoensis and Abies nephrolepis） ecotone growing on volcanic ejecta in the northern slope of Changbai Mountains of Northeast China, to compare soil carbon （C） and nitrogen （N） transformations in the two forests. The soil type is Umbri-Gelic Cambosols in Chinese Soil Taxonomy. Soil samples were incubated aerobically at 20℃ and field capacity of 700 g kg^-1 over a period of 27 weeks. The amount of soil microbial biomass and net N mineralization were higher in the Ermans birch than the dark coniferous forest （P 〈 0.05）, whereas the cumulative C mineralization （as CO2 emission） in the dark coniferous forest exceeded that in the Ermans birch （P 〈 0.05）. Release of the cumulative dissolved organic C and dissolved organic N were greater in the Ermans birch than the dark coniferous forest （P 〈 0.05）. The results suggested that differences of forest types could result in considerable change in soil C and N transformations.展开更多
As the largest developing country in the world, China has not be involved in the obligation of emissions reduction in the （〈Kyoto Protocol）） . But it has become the largest CO2 emissions countries in the world. Th...As the largest developing country in the world, China has not be involved in the obligation of emissions reduction in the （〈Kyoto Protocol）） . But it has become the largest CO2 emissions countries in the world. This makes China confronted with more pressure of carbon emissions reduction in the post-Kyoto era, and face great challenges in response to climate change issues. On one hand, China＇ s economic growth stage has decided that the situation of more energy consumption and increased carbon emissions is diffficult to reverse in the short term; On the other hand, the traditional policy under the control of total amount of carbon emission has largely restricted economic development. If a developing country in economic transition is carried out compulsory absolute amount of carbon reduction policies, its economic activity and social consumption will be imposed additional constraints inevitably, which will eventually lead to lower economic competitiveness and decline in social standards of living. Ultimately it will affect the good effects of carbon emissions reduction, so the policy can not achieve a satisfactory result. This paper introduces the financial mechanism into the carbon market model, extends the time of model from one phase to multi-phase. And this paper tries to establish a cross-time carbon credits trade system, and the current strength of the traditional carbon emission market trade model is extended. The paper designs two type of option mechanism model--call options trade carbon emissions model and put options carbon emissions model. Models＇ results show that choosing options tool to extend our traditional carbon market model can bring following impacts on carbon market development： trade costs have fallen, the carbon intensity also has descended, and has realized the flow of carbon intensity in diffident time; it enables manufacturers to effectively avoid the risk of carbon emissions trade; it increases the flexibility and maneuverability of the carbon trade market. Finally, the policy recommendations in the financial mechanisms carbon market trade are put forward.展开更多
With the implementation of the ＂Development of Western China＂ strategy, this region has become the fastest growing economic area in China. However, rapid economic growth has resulted in a substantial increase in car...With the implementation of the ＂Development of Western China＂ strategy, this region has become the fastest growing economic area in China. However, rapid economic growth has resulted in a substantial increase in carbon emissions and affected energy reduction goals. In order to effectively control the rapid increase in carbon emissions across western China, we need a comprehensively analyze the main factors causing these increases. Here, we analyze the relationship between economic development patterns and carbon emissions. The findings suggest that consumption upgrades and industrial transformation have a positive correlation with carbon emissions in this region. We then conducted an econometric FGLS analysis on the relationship and its transmission mechanism between economic growth and CO2 emissions with cross-province panel data from 1991 to 2009. A positive correlation was found, and the relationship is more significant after the implementation of the western development strategy. The influence coefficient of change in primary, secondary and tertiary industries is 16.4. The influence coefficient of increased share of heavy industry and extractive industry in the secondary industry is 14.3, and the influence coefficients of per-capita living expenditure and per capita traffic expenditure are 5.6 and 6.5. Traditional population size and income scale have a weak impact on carbon emissions, and the influence coefficients of population size and income scale are only 0.73 and 0.86. GDP increases have a second major impact on the carbon emissions. Energy intensity has a negative relationship with carbon emissions and urbanization level has a positive relationship （coefficients are -8.2 and 4.65）.展开更多
基金Project 50574038 supported by the National Natural Science Foundation of China
文摘Targeting the problem of large amounts of gas emission from the goaf of the No.14201 working face in the Shaqu coal mine of Huajin Coking Coal Co. Ltd., we used a negative exponential function to describe the attenuation process of gas emission in goaf (the stable source) based on the principle of field flow. Equations of two-component flow (gas and air) and seep- age-diffusion in a heterogeneous goaf flow field are solved by means of numerical simulation and fluid mechanics principles of air movement and gas distribution during gas emission from goaf. The results indicate that the air diversion volume has a negative, exponential relation with the volume of gas emitted from goaf to the working face and is clearly inversely related to gas concentra- tion. We calculated the minimum amount of air diversion and distributed air volume in the tailing roadway required for safe pro- duction.
文摘In this article, the authors propose the production of ethanol from cellulose as an alternative to oil. Cellulosic-ethanol will reduce greenhouse gas emissions, and provide a means to prevent forest fires. This liquid dense fuel was selected because it： （1） easily transported and dispensed as a fuel; （2） can be handled by the existing fuel distribution infrastructure; and （3） unlike its commercial competitor, Me-OH （Methanol）, Et-OH （Ethanol）, is edible, thus being biodegradable and nontoxic. Forest residue ethanol is cheaper to produce and more environmentally friendly than other forms of ethanol fuel. Furthermore, forests would have less available ground fuel for fires. The potential decline of forest fires would then reduce the carbon footprint attributed directly to forest fires. In combination with ethanol fuel combustion, carbon emissions can be reduced by more than 70% compared to gasoline combustion. We used GREET （Greenhouse gases, Regulated Emissions, and Energy use in Transportation） software to assess the life cycles of different fuel pathways. In conclusion, cellulosic ethanol fuel is clearly an answer to decrease dependency on current oil imports and prevent forest fires.
文摘Rice paddies are increasingly being converted to vegetable production due to economic benefits related,in part,to changes in demand during recent decades.Here,we implemented a parallel field experiment to simultaneously measure annual emissions of CH_4and N_2O,and soil organic carbon(SOC)stock changes,in rice paddies(RP),rice paddy–converted conventional vegetable fields(CV),and rice paddy–converted greenhouse vegetable fields(GV).Changing from rice to vegetable production reduced CH_4emissions by nearly 100%,and also triggered substantial N_2O emissions.Furthermore,annual N_2O emissions from GV significantly exceeded those from CV due to lower soil p H and higher soil temperature.Marginal SOC losses occurred after one year of cultivation of RP,CV,and GV,contributing an important share(3.4%,32.2%,and 10.3%,respectively)of the overall global warming potential(GWP)balance.The decline in CH_4emissions outweighed the increased N_2O emissions and SOC losses in CV and GV,leading to a 13%–30%reduction in annual GWP as compared to RP.These results suggest that large-scale expansion of vegetable production at the expense of rice paddies is beneficial for mitigating climate change in terms of the overall GWP.
基金Project supported by the National Natural Science Foundation of China(No.90411020)the National Key Basic Research Program(973 Program)of China(No.2002CB412502)
文摘Soil samples were taken from an Ermans birch （Betula ermanii）-dark coniferous forest （Picea jezoensis and Abies nephrolepis） ecotone growing on volcanic ejecta in the northern slope of Changbai Mountains of Northeast China, to compare soil carbon （C） and nitrogen （N） transformations in the two forests. The soil type is Umbri-Gelic Cambosols in Chinese Soil Taxonomy. Soil samples were incubated aerobically at 20℃ and field capacity of 700 g kg^-1 over a period of 27 weeks. The amount of soil microbial biomass and net N mineralization were higher in the Ermans birch than the dark coniferous forest （P 〈 0.05）, whereas the cumulative C mineralization （as CO2 emission） in the dark coniferous forest exceeded that in the Ermans birch （P 〈 0.05）. Release of the cumulative dissolved organic C and dissolved organic N were greater in the Ermans birch than the dark coniferous forest （P 〈 0.05）. The results suggested that differences of forest types could result in considerable change in soil C and N transformations.
文摘As the largest developing country in the world, China has not be involved in the obligation of emissions reduction in the （〈Kyoto Protocol）） . But it has become the largest CO2 emissions countries in the world. This makes China confronted with more pressure of carbon emissions reduction in the post-Kyoto era, and face great challenges in response to climate change issues. On one hand, China＇ s economic growth stage has decided that the situation of more energy consumption and increased carbon emissions is diffficult to reverse in the short term; On the other hand, the traditional policy under the control of total amount of carbon emission has largely restricted economic development. If a developing country in economic transition is carried out compulsory absolute amount of carbon reduction policies, its economic activity and social consumption will be imposed additional constraints inevitably, which will eventually lead to lower economic competitiveness and decline in social standards of living. Ultimately it will affect the good effects of carbon emissions reduction, so the policy can not achieve a satisfactory result. This paper introduces the financial mechanism into the carbon market model, extends the time of model from one phase to multi-phase. And this paper tries to establish a cross-time carbon credits trade system, and the current strength of the traditional carbon emission market trade model is extended. The paper designs two type of option mechanism model--call options trade carbon emissions model and put options carbon emissions model. Models＇ results show that choosing options tool to extend our traditional carbon market model can bring following impacts on carbon market development： trade costs have fallen, the carbon intensity also has descended, and has realized the flow of carbon intensity in diffident time; it enables manufacturers to effectively avoid the risk of carbon emissions trade; it increases the flexibility and maneuverability of the carbon trade market. Finally, the policy recommendations in the financial mechanisms carbon market trade are put forward.
基金Humanity and Social Science Youth foundation of Ministry of Education of China (12YJC790082)National Social Science Fund Key Project (11AJL007)
文摘With the implementation of the ＂Development of Western China＂ strategy, this region has become the fastest growing economic area in China. However, rapid economic growth has resulted in a substantial increase in carbon emissions and affected energy reduction goals. In order to effectively control the rapid increase in carbon emissions across western China, we need a comprehensively analyze the main factors causing these increases. Here, we analyze the relationship between economic development patterns and carbon emissions. The findings suggest that consumption upgrades and industrial transformation have a positive correlation with carbon emissions in this region. We then conducted an econometric FGLS analysis on the relationship and its transmission mechanism between economic growth and CO2 emissions with cross-province panel data from 1991 to 2009. A positive correlation was found, and the relationship is more significant after the implementation of the western development strategy. The influence coefficient of change in primary, secondary and tertiary industries is 16.4. The influence coefficient of increased share of heavy industry and extractive industry in the secondary industry is 14.3, and the influence coefficients of per-capita living expenditure and per capita traffic expenditure are 5.6 and 6.5. Traditional population size and income scale have a weak impact on carbon emissions, and the influence coefficients of population size and income scale are only 0.73 and 0.86. GDP increases have a second major impact on the carbon emissions. Energy intensity has a negative relationship with carbon emissions and urbanization level has a positive relationship （coefficients are -8.2 and 4.65）.
