Reservoir impoundment is related to several hydraulic engineering concerns,including irreversible valley contractions,landslides and reservoir-induced earthquakes.However,these phenomena,such as valley contractions,ar...Reservoir impoundment is related to several hydraulic engineering concerns,including irreversible valley contractions,landslides and reservoir-induced earthquakes.However,these phenomena,such as valley contractions,are hardly to be explained by the conventional method.The scientific understanding of water effects during impoundment and their hazards to hydraulic structure are needed.The effective stress law for fissured rock masses is introduced in the elasto-plastic model employing the Drucker-Prager criterion and implemented in the three dimension(3D)nonlinear finite element method(FEM)program Three-dimensional FINite Element(TFINE).The slope deforms towards river-way during impoundment since the increasing pore pressure in fissures changes stress state and leads to additional plastic deformation in the rock materials.The value of Biot coefficient and the influence of water on rock materials are discussed in detail.Thus,the mechanism of slope deformation during the impoundment of Jinping-I arch dam is revealed,and the deformation is accurately measured.The application of the effective stress law provides a method to consider stress assessment,deformation evaluation and stability estimate of hydraulic structures during the impoundment process.This is a beneficial exploration and an improvement of hydraulic engineering design.展开更多
CHINESE people like to bank their cash; this is evident in the 300 million deposit accounts currently in existence.China＇s national savings ratio approaches 50 percent, and 30 percent of its income is from family sav...CHINESE people like to bank their cash; this is evident in the 300 million deposit accounts currently in existence.China＇s national savings ratio approaches 50 percent, and 30 percent of its income is from family savings, says Stephen Roach, chief economist at Morgan Stanley,展开更多
In this article, a new kind of solar fresh air system is designed in order to realize the improvement of thermal efficiency by the integrated application of the PCMs and heat pipe technology. Under the adequate sunshi...In this article, a new kind of solar fresh air system is designed in order to realize the improvement of thermal efficiency by the integrated application of the PCMs and heat pipe technology. Under the adequate sunshine condition, the fresh air is directly delivered into the indoor environment after being heated by the solar collector. When the sun radiation is reduced, the heated air temperature can not satisfy the need of supply of air temperature.The main heat source is changed to phase change heat storage equipment instead of solar energy. The system adopt heat pipe for a high-efficiency and isothermal heat transfer which recover the shortcomings of PCMs such as： low coefficient of thermal conductivity and poor thermal efficiency. This article establishes the physical model of phase change solar energy fresh air thermal storage system and creates the mathematical model of its unsteady heat transfer to simulate and analyse the operation process by using Fluent software. The results of the study show that, compared to normal fresh air system, the phase change solar energy fresh air thermal storage system has a significant improvement in energy saving and indoor comfort level and will play an important role in the energy sustainable development.展开更多
On the basis of the 1992-2003 flow of funds accounts for China released by the National Statistics Bureau, this article conducts a comparative analysis of the saving rates of the household, corporate and government se...On the basis of the 1992-2003 flow of funds accounts for China released by the National Statistics Bureau, this article conducts a comparative analysis of the saving rates of the household, corporate and government sectors from the perspective of income distribution and saving propensity. We found that although the household sector had the highest saving rate, it had actually trended downwards since 1992, as a result of falling labor compensation, property income and income from redistribution. Over this period, the corporate saving rate rose slowly, mainly because of a prolonged period of relatively low wage and interest costs rather than increased profitability. The government saving rate, which remained low in the last century, rose dramatically after 2000. The main reasons for this were the ever- increasing share of government disposable revenue in national income distribution via primary distribution and redistribution and the sector＇s increased saving propensity. Our policy recommendations suggest that in order to implement an economic development strategy centered on boosting domestic consumption, China should shift its economic focus to improving the income distribution structure and increasing household income. For this purpose, fiscal policies should be oriented toward increased public financing, public expenditure and social security expenditure and toward higher labor compensation based on increased productivity in the corporate sector. These aims should be taken as the objectives of national c regulation.展开更多
基金Projects(51323014,51479097,51279086)supported by the National Natural Science Foundation of ChinaProject(2016-KY-2)supported by the State Key Laboratory of Hydroscience and Hydraulic Engineering,China
文摘Reservoir impoundment is related to several hydraulic engineering concerns,including irreversible valley contractions,landslides and reservoir-induced earthquakes.However,these phenomena,such as valley contractions,are hardly to be explained by the conventional method.The scientific understanding of water effects during impoundment and their hazards to hydraulic structure are needed.The effective stress law for fissured rock masses is introduced in the elasto-plastic model employing the Drucker-Prager criterion and implemented in the three dimension(3D)nonlinear finite element method(FEM)program Three-dimensional FINite Element(TFINE).The slope deforms towards river-way during impoundment since the increasing pore pressure in fissures changes stress state and leads to additional plastic deformation in the rock materials.The value of Biot coefficient and the influence of water on rock materials are discussed in detail.Thus,the mechanism of slope deformation during the impoundment of Jinping-I arch dam is revealed,and the deformation is accurately measured.The application of the effective stress law provides a method to consider stress assessment,deformation evaluation and stability estimate of hydraulic structures during the impoundment process.This is a beneficial exploration and an improvement of hydraulic engineering design.
文摘CHINESE people like to bank their cash; this is evident in the 300 million deposit accounts currently in existence.China＇s national savings ratio approaches 50 percent, and 30 percent of its income is from family savings, says Stephen Roach, chief economist at Morgan Stanley,
文摘In this article, a new kind of solar fresh air system is designed in order to realize the improvement of thermal efficiency by the integrated application of the PCMs and heat pipe technology. Under the adequate sunshine condition, the fresh air is directly delivered into the indoor environment after being heated by the solar collector. When the sun radiation is reduced, the heated air temperature can not satisfy the need of supply of air temperature.The main heat source is changed to phase change heat storage equipment instead of solar energy. The system adopt heat pipe for a high-efficiency and isothermal heat transfer which recover the shortcomings of PCMs such as： low coefficient of thermal conductivity and poor thermal efficiency. This article establishes the physical model of phase change solar energy fresh air thermal storage system and creates the mathematical model of its unsteady heat transfer to simulate and analyse the operation process by using Fluent software. The results of the study show that, compared to normal fresh air system, the phase change solar energy fresh air thermal storage system has a significant improvement in energy saving and indoor comfort level and will play an important role in the energy sustainable development.
文摘On the basis of the 1992-2003 flow of funds accounts for China released by the National Statistics Bureau, this article conducts a comparative analysis of the saving rates of the household, corporate and government sectors from the perspective of income distribution and saving propensity. We found that although the household sector had the highest saving rate, it had actually trended downwards since 1992, as a result of falling labor compensation, property income and income from redistribution. Over this period, the corporate saving rate rose slowly, mainly because of a prolonged period of relatively low wage and interest costs rather than increased profitability. The government saving rate, which remained low in the last century, rose dramatically after 2000. The main reasons for this were the ever- increasing share of government disposable revenue in national income distribution via primary distribution and redistribution and the sector＇s increased saving propensity. Our policy recommendations suggest that in order to implement an economic development strategy centered on boosting domestic consumption, China should shift its economic focus to improving the income distribution structure and increasing household income. For this purpose, fiscal policies should be oriented toward increased public financing, public expenditure and social security expenditure and toward higher labor compensation based on increased productivity in the corporate sector. These aims should be taken as the objectives of national c regulation.
