At the interface between the lower atmosphere and sea surface,sea spray might significantly influence air-sea heat fluxes and subsequently,modulate upper ocean temperature during a typhoon passage. The effects of sea ...At the interface between the lower atmosphere and sea surface,sea spray might significantly influence air-sea heat fluxes and subsequently,modulate upper ocean temperature during a typhoon passage. The effects of sea spray were introduced into the parameterization of sea surface roughness in a 1-D turbulent model,to investigate the effects of sea spray on upper ocean temperature in the Kuroshio Extension area,for the cases of two real typhoons from 2006,Yagi and Soulik. Model output was compared with data from the Kuroshio Extension Observatory(KEO),and Reynolds and AMSRE satellite remote sensing sea surface temperatures. The results indicate drag coefficients that include the spray effect are closer to observations than those without,and that sea spray can enhance the heat fluxes(especially latent heat flux) considerably during a typhoon passage. Consequently,the model results with heat fluxes enhanced by sea spray simulate better the cooling process of the SST and upper-layer temperature profiles. Additionally,results from the simulation of the passage of typhoon Soulik(that passed KEO quickly),which included the sea spray effect,were better than for the simulated passage of typhoon Yagi(that crossed KEO slowly). These promising 1-D results could provide insight into the application of sea spray in general circulation models for typhoon studies.展开更多
In this paper,the designed features of a W-flame coal-fired boiler are introduced.A scheme of joint primary air for two boilers is made and technical measures are also taken based on corresponding analyses and studies...In this paper,the designed features of a W-flame coal-fired boiler are introduced.A scheme of joint primary air for two boilers is made and technical measures are also taken based on corresponding analyses and studies.The scheme and the measures provide a reference for technicians to improve the efficiencies and reduce the startup costs of other similar large boilers.展开更多
The effects of different yaw angles on the aerodynamic performance of city electric multiple units(EMUs)were investigated in a wind tunnel using a 1:16.8 scaled model.Pressure scanning valve and six-component box-type...The effects of different yaw angles on the aerodynamic performance of city electric multiple units(EMUs)were investigated in a wind tunnel using a 1:16.8 scaled model.Pressure scanning valve and six-component box-type aerodynamic balance were used to test the pressure distribution and aerodynamic force of the head car respectively from the 1.5-and 3-coach grouping city EMU models.Meanwhile,the effects of the yaw angles on the pressure distribution of the streamlined head as well as the aerodynamic forces of the train were analyzed.The experimental results showed that the pressure coefficient was the smallest at the maximum slope of the main shape-line.The side force coefficient and pressure coefficient along the head car cross-section were most affected by crosswind when the yaw angle was 55°,and replacing a 3-coach grouping with a 1.5-coach grouping had obvious advantages for wind tunnel testing when the yaw angle was within 24.2°.In addition,the relative errors of lift coefficient C_(L),roll moment coefficient C_(Mx),side force coefficient C_(S),and drag coefficient C_(D) between the 1.5-and 3-coach cases were below 5.95%,which all met the requirements of the experimental accuracy.展开更多
Appropriate wind power integration standards are of great importance to standardize wind power integration and guarantee the safety and stability of the power system. This article describes the wind power integration ...Appropriate wind power integration standards are of great importance to standardize wind power integration and guarantee the safety and stability of the power system. This article describes the wind power integration standards of China explicitly and explains several important points of the newly revised wind power integration standards of China in comparison with standards of Germany, Denmark, etc. The newly revised standards can meet the technical demand of China's large-scale centralized development of wind power, and guarantee the safety, stability and economy of the grid and wind farm.展开更多
The aim of this paper is to test the ability of conditional and unconditional capital asset pricing models (CAPMs) and to explain emerging markets returns in terms of their integration into the international market....The aim of this paper is to test the ability of conditional and unconditional capital asset pricing models (CAPMs) and to explain emerging markets returns in terms of their integration into the international market. The authors use data on five developed countries and five emerging countries as well as data on the Tunis Stock Exchange (TSE) after the reforms. The results show that the correlations between emerging markets returns and developed markets returns are very low and sometimes negative. Conditional arbitrage pricing theory (APT) as well as conditional CAPM has low predictive power for emerging markets than that for developed markets. Finally, following the financial reforms, Tunisian financial markets have became more and more integrated into the international market (excess returns and unconditional beta consistent with predictions). However, conditional APT does not accurately explain Tunisian market returns. This study confirms the unavailability of an accurate modelling technique of the TSE structure.展开更多
One-dimensional linear regression equation between measured value of air velocity transducer and the average air velocity was established by experimental data. The effect is to be evaluated. Through judging the parame...One-dimensional linear regression equation between measured value of air velocity transducer and the average air velocity was established by experimental data. The effect is to be evaluated. Through judging the parameters, one-dimensional linear equation established is valid. Regression equation can approximately put the measurements of air velocity transducer into the value of average air velocity. The distribution of air velocity field is simulated using Comsol in the conditions of the same length of roadway, the same air velocity and different sections.展开更多
The paper analyzes different turbine design suitable for the urban environment. The author discusses various options for setting up wind turbines in relation to the building. In order to gain insight into the real ind...The paper analyzes different turbine design suitable for the urban environment. The author discusses various options for setting up wind turbines in relation to the building. In order to gain insight into the real indicators, considered are actual examples of wind turbines mounted on buildings, sports facilities, roads, etc. However, these turbines have relatively low efficiency and a long payback period, and the problem may be the noise they produce. Therefore, the wind turbines installed in buildings are still more a matter of prestige of individual investors and architects than profitable investment.展开更多
The insurance industry has gained remarkable and initial results in the industrial standardization over the past eight years, played a positive role in promoting the industry informatization and standardizing the busi...The insurance industry has gained remarkable and initial results in the industrial standardization over the past eight years, played a positive role in promoting the industry informatization and standardizing the business management, and made a contribution to the normalized, sustainable, healthy and rapid development of the industry. Meanwhile, the development of insm'ance industry has put forward new requirements for the insurance standardization. It is essential to strategically match the industrial development and industry standardization, and grasp the developmental direction of insurance standardization, make sure that standardization work serves the reform and development of insurance industry, prevention and diffusion of insurance risks, and insurance informatization, and focus on the promotion, implementation and supervision of standards.展开更多
Aiming for the restoration of degraded ecosystems, many ecological engineering projects have been implemented around the world. This study investigates the ecological engineering project effectiveness on vegetation re...Aiming for the restoration of degraded ecosystems, many ecological engineering projects have been implemented around the world. This study investigates the ecological engineering project effectiveness on vegetation restoration in the Beijing-Tianjin Sand Source Region(BTSSR) from 2000 to 2010 based on the rain use efficiency(RUE) trend in relation to the land cover. More than half of the BTSSR experienced a vegetation productivity increase from 2000 to 2010, with the increasing intensity being sensitive to the indicators chosen. A clear tendency towards smaller increasing areas was shown when using the net primary productivity(NPP, 51.30%) instead of the accumulated normalized difference vegetation index(59.30%). The short-term variation in the precipitation and intra-seasonal precipitation distribution had a great impact on the remote sensing-based vegetation productivity. However, the residual trends method(RESTREND) effectively eliminated this correlation, while incorporating the variance and skewness of the precipitation distribution increased the models′ ability to explain the vegetation productivity variation. The RUE combined with land cover dynamics was valid for the effectiveness assessment of the ecological engineering projects on vegetation restoration. Particularly, the result based on growing season accumulated normalized difference vegetation index(ΣNDVI) residuals was the most effective, showing that 47.39% of the BTSSR experienced vegetation restoration from 2000 to 2010. The effectiveness of the ecological engineering projects differed for each subarea and was proportional to the strength of ecological engineering. The water erosion region dominated by woodland showed the best restoration, followed by the wind-water erosion crisscross regions, while the wind erosion regions dominated by grassland showed the worst effect. Seriously degraded regions still cover more area in the BTSSR than restored regions. Therefore, more future effort should be put in restoring degraded land.展开更多
During A.D. 776 to 848, Dunhuang was occupied and ruled by Tubo political power, a special painting style, spread via the Tibetan silk road, appeared at same time, and which is related to the art style of India and Ne...During A.D. 776 to 848, Dunhuang was occupied and ruled by Tubo political power, a special painting style, spread via the Tibetan silk road, appeared at same time, and which is related to the art style of India and Nepal; It is worth noting that the Tibetan painting style during this period have no relative unified model actually, especially the mural and the silk painting preserved in Library Cave, the painting style of which had obvious difference between each other, and the reason behind this is very hard to explain. Until the late Tang Dynasty (A.D. 848-907), sheer Pala style of eastern India appeared in Dunhuang, however, whether those East India painting style still belong to Tubo remain for further discussion. The art style of East India appeared in Dunhuang during from the late Tang Dynasty to the early period of Northern Song Dynasty, probably propagated from the ways other than Tubo, and this art style was deemed as the one has nothing to do with Tibet's art in this study.展开更多
Carbon monoxide (CO) intoxication is one of the most common types of poisoning in the modem world. To better tailor messages and communication needs to the public, a perception survey of CO and his risk was conducte...Carbon monoxide (CO) intoxication is one of the most common types of poisoning in the modem world. To better tailor messages and communication needs to the public, a perception survey of CO and his risk was conducted among the population of Rabat-Sale-Zemmour-Zaer. The authors included 400 people in this survey. The demographic characteristics of the respondents consisted of: 85.0% female, 92.9% adults, 29.7% had a high level of education, 49.6% unemployed, 89.5% were home owners and 53.9% lived in apartments. Water heaters were present in the homes of 91.0% of respondents and 6.5% of them used gas. Gas was used as fuel in 45.4% of cases. For water heaters, 20.8% had an exhaust duct, 9.9% were serviced regularly and 47.5% were installed in a well ventilated area. Regarding the media, television was the medium that allowed 73.4% of the CO to know, regardless of age, sex and level of education among the 94.3% of who ever heard of this deadly gas before the survey.展开更多
In the past fifteen years, the attention of ship safety treatment as an objective rather than a constraint has started to sweep through the whole maritime industry. The risk-based ship design (RBD) methodology, advo...In the past fifteen years, the attention of ship safety treatment as an objective rather than a constraint has started to sweep through the whole maritime industry. The risk-based ship design (RBD) methodology, advocating systematic integration of risk assessment within the conventional design process has started to takeoff. Despite this wide recognition and increasing popularity, important factors that could potentially undermine the quality of the results come from both quantitative and qualitative aspects during the risk assessment process. This paper details a promising solution by developing a formalized methodology for risk assessment through effective storing and processing of historical data combined with data generated through first-principle approaches. This method should help to generate appropriate risk models in the selected platform (Bayesian networks) which can be employed for decision making at design stare.展开更多
基金Supported by the National Basic Research Program of China(973 Program)(No.2013CB430304)the National Natural Science Foundation of China(Nos.41030854,41106005,41176003,41206178,41376015,41376013,41306006)+1 种基金the National High-Tech R&D Program of China(No.2013AA09A505)the Public Science and Technology Research Funds Projects of Ocean(No.20130531-8)
文摘At the interface between the lower atmosphere and sea surface,sea spray might significantly influence air-sea heat fluxes and subsequently,modulate upper ocean temperature during a typhoon passage. The effects of sea spray were introduced into the parameterization of sea surface roughness in a 1-D turbulent model,to investigate the effects of sea spray on upper ocean temperature in the Kuroshio Extension area,for the cases of two real typhoons from 2006,Yagi and Soulik. Model output was compared with data from the Kuroshio Extension Observatory(KEO),and Reynolds and AMSRE satellite remote sensing sea surface temperatures. The results indicate drag coefficients that include the spray effect are closer to observations than those without,and that sea spray can enhance the heat fluxes(especially latent heat flux) considerably during a typhoon passage. Consequently,the model results with heat fluxes enhanced by sea spray simulate better the cooling process of the SST and upper-layer temperature profiles. Additionally,results from the simulation of the passage of typhoon Soulik(that passed KEO quickly),which included the sea spray effect,were better than for the simulated passage of typhoon Yagi(that crossed KEO slowly). These promising 1-D results could provide insight into the application of sea spray in general circulation models for typhoon studies.
文摘In this paper,the designed features of a W-flame coal-fired boiler are introduced.A scheme of joint primary air for two boilers is made and technical measures are also taken based on corresponding analyses and studies.The scheme and the measures provide a reference for technicians to improve the efficiencies and reduce the startup costs of other similar large boilers.
基金Project(2020YFA0710903) supported by the National Key R&D Program of ChinaProjects(2020zzts111, 2020zzts117)supported by the Graduate Student Independent Innovation Project of Central South University,ChinaProject(202037)supported by Transport Department of Hunan Province Technology Innovation Project,China。
文摘The effects of different yaw angles on the aerodynamic performance of city electric multiple units(EMUs)were investigated in a wind tunnel using a 1:16.8 scaled model.Pressure scanning valve and six-component box-type aerodynamic balance were used to test the pressure distribution and aerodynamic force of the head car respectively from the 1.5-and 3-coach grouping city EMU models.Meanwhile,the effects of the yaw angles on the pressure distribution of the streamlined head as well as the aerodynamic forces of the train were analyzed.The experimental results showed that the pressure coefficient was the smallest at the maximum slope of the main shape-line.The side force coefficient and pressure coefficient along the head car cross-section were most affected by crosswind when the yaw angle was 55°,and replacing a 3-coach grouping with a 1.5-coach grouping had obvious advantages for wind tunnel testing when the yaw angle was within 24.2°.In addition,the relative errors of lift coefficient C_(L),roll moment coefficient C_(Mx),side force coefficient C_(S),and drag coefficient C_(D) between the 1.5-and 3-coach cases were below 5.95%,which all met the requirements of the experimental accuracy.
文摘Appropriate wind power integration standards are of great importance to standardize wind power integration and guarantee the safety and stability of the power system. This article describes the wind power integration standards of China explicitly and explains several important points of the newly revised wind power integration standards of China in comparison with standards of Germany, Denmark, etc. The newly revised standards can meet the technical demand of China's large-scale centralized development of wind power, and guarantee the safety, stability and economy of the grid and wind farm.
文摘The aim of this paper is to test the ability of conditional and unconditional capital asset pricing models (CAPMs) and to explain emerging markets returns in terms of their integration into the international market. The authors use data on five developed countries and five emerging countries as well as data on the Tunis Stock Exchange (TSE) after the reforms. The results show that the correlations between emerging markets returns and developed markets returns are very low and sometimes negative. Conditional arbitrage pricing theory (APT) as well as conditional CAPM has low predictive power for emerging markets than that for developed markets. Finally, following the financial reforms, Tunisian financial markets have became more and more integrated into the international market (excess returns and unconditional beta consistent with predictions). However, conditional APT does not accurately explain Tunisian market returns. This study confirms the unavailability of an accurate modelling technique of the TSE structure.
基金Supported by the National Natural Science Foundation of China (51174109)
文摘One-dimensional linear regression equation between measured value of air velocity transducer and the average air velocity was established by experimental data. The effect is to be evaluated. Through judging the parameters, one-dimensional linear equation established is valid. Regression equation can approximately put the measurements of air velocity transducer into the value of average air velocity. The distribution of air velocity field is simulated using Comsol in the conditions of the same length of roadway, the same air velocity and different sections.
文摘The paper analyzes different turbine design suitable for the urban environment. The author discusses various options for setting up wind turbines in relation to the building. In order to gain insight into the real indicators, considered are actual examples of wind turbines mounted on buildings, sports facilities, roads, etc. However, these turbines have relatively low efficiency and a long payback period, and the problem may be the noise they produce. Therefore, the wind turbines installed in buildings are still more a matter of prestige of individual investors and architects than profitable investment.
文摘The insurance industry has gained remarkable and initial results in the industrial standardization over the past eight years, played a positive role in promoting the industry informatization and standardizing the business management, and made a contribution to the normalized, sustainable, healthy and rapid development of the industry. Meanwhile, the development of insm'ance industry has put forward new requirements for the insurance standardization. It is essential to strategically match the industrial development and industry standardization, and grasp the developmental direction of insurance standardization, make sure that standardization work serves the reform and development of insurance industry, prevention and diffusion of insurance risks, and insurance informatization, and focus on the promotion, implementation and supervision of standards.
基金Under the auspices of National Natural Science Foundation of China(No.41571421)National Science and Technology Major Project of China(No.21-Y30B05-9001-13/15)
文摘Aiming for the restoration of degraded ecosystems, many ecological engineering projects have been implemented around the world. This study investigates the ecological engineering project effectiveness on vegetation restoration in the Beijing-Tianjin Sand Source Region(BTSSR) from 2000 to 2010 based on the rain use efficiency(RUE) trend in relation to the land cover. More than half of the BTSSR experienced a vegetation productivity increase from 2000 to 2010, with the increasing intensity being sensitive to the indicators chosen. A clear tendency towards smaller increasing areas was shown when using the net primary productivity(NPP, 51.30%) instead of the accumulated normalized difference vegetation index(59.30%). The short-term variation in the precipitation and intra-seasonal precipitation distribution had a great impact on the remote sensing-based vegetation productivity. However, the residual trends method(RESTREND) effectively eliminated this correlation, while incorporating the variance and skewness of the precipitation distribution increased the models′ ability to explain the vegetation productivity variation. The RUE combined with land cover dynamics was valid for the effectiveness assessment of the ecological engineering projects on vegetation restoration. Particularly, the result based on growing season accumulated normalized difference vegetation index(ΣNDVI) residuals was the most effective, showing that 47.39% of the BTSSR experienced vegetation restoration from 2000 to 2010. The effectiveness of the ecological engineering projects differed for each subarea and was proportional to the strength of ecological engineering. The water erosion region dominated by woodland showed the best restoration, followed by the wind-water erosion crisscross regions, while the wind erosion regions dominated by grassland showed the worst effect. Seriously degraded regions still cover more area in the BTSSR than restored regions. Therefore, more future effort should be put in restoring degraded land.
文摘During A.D. 776 to 848, Dunhuang was occupied and ruled by Tubo political power, a special painting style, spread via the Tibetan silk road, appeared at same time, and which is related to the art style of India and Nepal; It is worth noting that the Tibetan painting style during this period have no relative unified model actually, especially the mural and the silk painting preserved in Library Cave, the painting style of which had obvious difference between each other, and the reason behind this is very hard to explain. Until the late Tang Dynasty (A.D. 848-907), sheer Pala style of eastern India appeared in Dunhuang, however, whether those East India painting style still belong to Tubo remain for further discussion. The art style of East India appeared in Dunhuang during from the late Tang Dynasty to the early period of Northern Song Dynasty, probably propagated from the ways other than Tubo, and this art style was deemed as the one has nothing to do with Tibet's art in this study.
文摘Carbon monoxide (CO) intoxication is one of the most common types of poisoning in the modem world. To better tailor messages and communication needs to the public, a perception survey of CO and his risk was conducted among the population of Rabat-Sale-Zemmour-Zaer. The authors included 400 people in this survey. The demographic characteristics of the respondents consisted of: 85.0% female, 92.9% adults, 29.7% had a high level of education, 49.6% unemployed, 89.5% were home owners and 53.9% lived in apartments. Water heaters were present in the homes of 91.0% of respondents and 6.5% of them used gas. Gas was used as fuel in 45.4% of cases. For water heaters, 20.8% had an exhaust duct, 9.9% were serviced regularly and 47.5% were installed in a well ventilated area. Regarding the media, television was the medium that allowed 73.4% of the CO to know, regardless of age, sex and level of education among the 94.3% of who ever heard of this deadly gas before the survey.
基金the financial support received by the University of Strathclyde in the form of a postgraduate research scholarship for the duration of the second author’s P hD studies
文摘In the past fifteen years, the attention of ship safety treatment as an objective rather than a constraint has started to sweep through the whole maritime industry. The risk-based ship design (RBD) methodology, advocating systematic integration of risk assessment within the conventional design process has started to takeoff. Despite this wide recognition and increasing popularity, important factors that could potentially undermine the quality of the results come from both quantitative and qualitative aspects during the risk assessment process. This paper details a promising solution by developing a formalized methodology for risk assessment through effective storing and processing of historical data combined with data generated through first-principle approaches. This method should help to generate appropriate risk models in the selected platform (Bayesian networks) which can be employed for decision making at design stare.