Study of CTD data collected by the R/V DONG FANG HONG 2 in a 1997 summercruise in the ocean region around the Ryukyu Islands showed: 1) the existence, in the upper layer, of ahigh salinity water (HSW) core at about 20...Study of CTD data collected by the R/V DONG FANG HONG 2 in a 1997 summercruise in the ocean region around the Ryukyu Islands showed: 1) the existence, in the upper layer, of ahigh salinity water (HSW) core at about 200 dbar, and a low salinity water (LSW) core, centered atabout 700 dbar on the Pacific Ocean side of the Ryukyu Ridge, and located shallower on the East Chinafor (ECS) side; 2) the existence, in the upper layer, of warm water regions (WWR) west of Amami Is-land and Ishigaki Island, and a cold water region (CWR) east of Okinawa Ieland; in the lower layer, ofa CWR (WWR) southwest (southeast) of Okinawa Island; 3) the intrusion of North Pacific IntermediateWater into the ECS through the Kerama Trench located south of Okinawa Island and the strait east of Tai-wan Island.展开更多
It has been a focus to reduce the energy consumption and improve the space heating performance of high-altitude buildings in winter seasons. In view of the abundant solar energy resources of the high-altitude region, ...It has been a focus to reduce the energy consumption and improve the space heating performance of high-altitude buildings in winter seasons. In view of the abundant solar energy resources of the high-altitude region, the establishment of passive solar houses should be an effective strategy to deal with the problem of thermal comfort. Both window to wall ratio(WWR) and sunspace depth are of vital importance to determine the thermal comfort level of passive solar houses, while there are limited studies on analyzing their impacts on passive solar houses in high-altitude regions. Therefore, this study is designed to examine how WWR and sunspace depth affect space heating of passive solar houses in the Qinghai-Tibetan region. To be specific, the hourly radiation temperature variations and percentages of dissatisfaction of the residential building with different sunspace depth/WWR(including 0.9 m/33%, 0.9 m/45%, 0.9 m/60%, 1.2 m/33% and 1.5 m/33%) were quantitatively examined. Results indicated that under the condition of 0.9 m/45%, the overall average radiation temperature of the building was approximately 16°C during the entire heating season, which could better satisfy the heating requirements. Meanwhile, the average temperature was higher, and the thermal comfort level was better under the ratio of 45% or the depth of 1.5 m, when only an individual factor in either ratio or depth was considered. These findings can provide references for the determination of dimensions of passive solar houses in high-altitude regions.展开更多
The current study investigates the behavior of wire electric discharge machining （WEDM） of the super alloy Udimet-L605 by employing sophisticated machine learning approaches. The experimental work was designed on th...The current study investigates the behavior of wire electric discharge machining （WEDM） of the super alloy Udimet-L605 by employing sophisticated machine learning approaches. The experimental work was designed on the basis of the Taguchi orthogonal L27 array, consid- ering six explanatory variables and evaluating their influ- ences on the cutting speed, wire wear ratio （WWR）, and dimensional deviation （DD）. A support vector machine （SVM） algorithm using a normalized poly-kernel and a radial-basis flow kernel is recommended for modeling the wire electric discharge machining process. The grey rela- tional analysis （GRA） approach was utilized to obtain the optimal combination of process variables simultaneously, providing the desirable outcome for the cutting speed, WWR, and DD. Scanning electron microscope and energy dispersive X-ray analyses of the samples were performed for the confirmation of the results. An SVM based on the radial-basis kernel model dominated the normalized poly- kernel model. The optimal combination of process vari- ables for a mutually desirable outcome for the cutting speed, WWR, and DD was determined as Ton1, Toffa, Ip1, WT3, SV1, and WF3. The pulse-on time is the significant variable influencing the cutting speed, WWR, and DD. The largest percentage of copper （8.66%） was observed at the highest cutting speed setting 7.05% of copper at the low of the machine compared to cutting speed setting of the machine.展开更多
This paper attempts to resolve the reported contradiction in the literature about the characteristics of high-performance/cost-effective fenestration of residential buildings,particularly in hot climates.The considere...This paper attempts to resolve the reported contradiction in the literature about the characteristics of high-performance/cost-effective fenestration of residential buildings,particularly in hot climates.The considered issues are the window glazing property(ten commercial glazing types),facade orientation(four main orientations),window-to-wall ratio(WWR)(0.2–0.8),and solar shading overhangs and side-fins(nine shading conditions).The results of the simulated runs reveal that the glazing quality has a superior effect over the other fenestration parameters and controls their effect on the energy consumption of residential buildings.Thus,using low-performance windows on buildings yields larger effects of WWR,facade orientation,and solar shading than high-performance windows.As the WWR increases from 0.2 to 0.8,the building energy consumption using the low-performance window increases 6.46 times than that using the highperformance window.The best facade orientation is changed from north to south according to the glazing properties.In addition,the solar shading need is correlated as a function of a window-glazing property and WWR.The cost analysis shows that the high-performance windows without solar shading are cost-effective as they have the largest net present cost compared to lowperformance windows with or without solar shading.Accordingly,replacing low-performance windows with high-performance ones,in an existing residential building,saves about 12.7 MWh of electricity and 11.05 tons of CO_(2) annually.展开更多
文摘Study of CTD data collected by the R/V DONG FANG HONG 2 in a 1997 summercruise in the ocean region around the Ryukyu Islands showed: 1) the existence, in the upper layer, of ahigh salinity water (HSW) core at about 200 dbar, and a low salinity water (LSW) core, centered atabout 700 dbar on the Pacific Ocean side of the Ryukyu Ridge, and located shallower on the East Chinafor (ECS) side; 2) the existence, in the upper layer, of warm water regions (WWR) west of Amami Is-land and Ishigaki Island, and a cold water region (CWR) east of Okinawa Ieland; in the lower layer, ofa CWR (WWR) southwest (southeast) of Okinawa Island; 3) the intrusion of North Pacific IntermediateWater into the ECS through the Kerama Trench located south of Okinawa Island and the strait east of Tai-wan Island.
基金supported by National Key R&D Program of China-Technical System and Key Technology Development of Nearly Zero Energy Building (No. 2017YFC0702600)the opening Funds of State Key Laboratory of Building Safety and Built Environment National Engineering Research Center of Building Technology (BSBE2017-08)+1 种基金the Major Basic Research Development and Transformation Program of Qinghai province (No. 2016-NN-141 )the Fundamental Research Funds for the Central Universities (No. 2018MS103, 2018MS108 and 2017MS119 )
文摘It has been a focus to reduce the energy consumption and improve the space heating performance of high-altitude buildings in winter seasons. In view of the abundant solar energy resources of the high-altitude region, the establishment of passive solar houses should be an effective strategy to deal with the problem of thermal comfort. Both window to wall ratio(WWR) and sunspace depth are of vital importance to determine the thermal comfort level of passive solar houses, while there are limited studies on analyzing their impacts on passive solar houses in high-altitude regions. Therefore, this study is designed to examine how WWR and sunspace depth affect space heating of passive solar houses in the Qinghai-Tibetan region. To be specific, the hourly radiation temperature variations and percentages of dissatisfaction of the residential building with different sunspace depth/WWR(including 0.9 m/33%, 0.9 m/45%, 0.9 m/60%, 1.2 m/33% and 1.5 m/33%) were quantitatively examined. Results indicated that under the condition of 0.9 m/45%, the overall average radiation temperature of the building was approximately 16°C during the entire heating season, which could better satisfy the heating requirements. Meanwhile, the average temperature was higher, and the thermal comfort level was better under the ratio of 45% or the depth of 1.5 m, when only an individual factor in either ratio or depth was considered. These findings can provide references for the determination of dimensions of passive solar houses in high-altitude regions.
文摘The current study investigates the behavior of wire electric discharge machining （WEDM） of the super alloy Udimet-L605 by employing sophisticated machine learning approaches. The experimental work was designed on the basis of the Taguchi orthogonal L27 array, consid- ering six explanatory variables and evaluating their influ- ences on the cutting speed, wire wear ratio （WWR）, and dimensional deviation （DD）. A support vector machine （SVM） algorithm using a normalized poly-kernel and a radial-basis flow kernel is recommended for modeling the wire electric discharge machining process. The grey rela- tional analysis （GRA） approach was utilized to obtain the optimal combination of process variables simultaneously, providing the desirable outcome for the cutting speed, WWR, and DD. Scanning electron microscope and energy dispersive X-ray analyses of the samples were performed for the confirmation of the results. An SVM based on the radial-basis kernel model dominated the normalized poly- kernel model. The optimal combination of process vari- ables for a mutually desirable outcome for the cutting speed, WWR, and DD was determined as Ton1, Toffa, Ip1, WT3, SV1, and WF3. The pulse-on time is the significant variable influencing the cutting speed, WWR, and DD. The largest percentage of copper （8.66%） was observed at the highest cutting speed setting 7.05% of copper at the low of the machine compared to cutting speed setting of the machine.
基金funded by the Public Authority for Applied Education and Training(PAAET)under project number TS-08-14.
文摘This paper attempts to resolve the reported contradiction in the literature about the characteristics of high-performance/cost-effective fenestration of residential buildings,particularly in hot climates.The considered issues are the window glazing property(ten commercial glazing types),facade orientation(four main orientations),window-to-wall ratio(WWR)(0.2–0.8),and solar shading overhangs and side-fins(nine shading conditions).The results of the simulated runs reveal that the glazing quality has a superior effect over the other fenestration parameters and controls their effect on the energy consumption of residential buildings.Thus,using low-performance windows on buildings yields larger effects of WWR,facade orientation,and solar shading than high-performance windows.As the WWR increases from 0.2 to 0.8,the building energy consumption using the low-performance window increases 6.46 times than that using the highperformance window.The best facade orientation is changed from north to south according to the glazing properties.In addition,the solar shading need is correlated as a function of a window-glazing property and WWR.The cost analysis shows that the high-performance windows without solar shading are cost-effective as they have the largest net present cost compared to lowperformance windows with or without solar shading.Accordingly,replacing low-performance windows with high-performance ones,in an existing residential building,saves about 12.7 MWh of electricity and 11.05 tons of CO_(2) annually.
