Research on the influence of thermal radiation of tree canopies to adjacent exterior walls has relevance to the selection of tree species and the spatial arrangement of trees for urban planning.In the last decade,ther...Research on the influence of thermal radiation of tree canopies to adjacent exterior walls has relevance to the selection of tree species and the spatial arrangement of trees for urban planning.In the last decade,there have been many studies on the influence of tree shadows on the thermal environment and energy consumption of buildings.However,there is a lack of research on how trees affect the thermal radiation of adjacent buildings,when they do not cast direct shadows on the walls.In view of this,a combination of experiment and simulation was used to explore the influence of spherical canopy on the intensity changes of net long-wave thermal radiation(T_(RDL))and net short-wave thermal radiation(T_(RDS))absorbed by the adjacent wall.Both measured and simulated results show that the tree canopy has a T_(RD)(the sum of T_(RDL) and T_(RDS))effect on the south wall of adjacent buildings in summer.The peak of T_(RD) from the tree to the adjacent wall was obtained by ENVI-met under 27 scenarios.A functional relationship was further given between the peak T_(RD) and the canopy diameter(D_(C)),the minimum distance between wall and tree canopy(D_(W-T)).Moreover,the influence of D_(C),D_(W-T) and leaf area density(LAD)on T_(RD) was discussed by simulation.Additionally,the Trd of canopy decays exponentially in the horizontal direction and linearly in the vertical direction of the wall.The above methods and results can guide the selection of tree species,green space design around buildings and the evaluation of the influence of trees on indoor cooling energy consumption in summer.展开更多
Confronted with severe frost damage to plants,methods,technologies and equipment have been developed and applied during the past century.The paper presents a comprehensive review on the most effective and active techn...Confronted with severe frost damage to plants,methods,technologies and equipment have been developed and applied during the past century.The paper presents a comprehensive review on the most effective and active technology to protect plants from radiation frost based on air disturbance technology.The working principle of the technology was elaborated with frost protection mechanism,structures and applicability of three types of working patterns:conventional wind machines,selective inverted sink and portable vertical blowing.As an automatic mechanized technology,control strategy,applicable occasion and proper parameters are introduced for each type of working pattern.The operation of the technology and equipment depends on plant critical temperature,prevailing climatic conditions,thermal inversions strength,as well as costs.The frost protection performance and effectiveness of conventional horizontal wind machines,selective inverted sinks and helicopters are discussed and compared from the cost-effectiveness and application aspects,and the feasibility of selective inverted sinks is still controversial.Therefore,conventional wind machines are the best choice for plant frost protection and consequently are widely used in temperate and subtropical areas throughout the world.The frost protection application with helicopters is not easy to use during the frost nights with high cost.The paper also provides researchers with some perspectives on improving air disturbance technology and its equipment,and some practice recommendations for growers.展开更多
Array sensing is increasingly important in the development of microcantilever(MC) sensors, and response consistency is the foundation for MC array sensing. In the present work, we investigated the response consistency...Array sensing is increasingly important in the development of microcantilever(MC) sensors, and response consistency is the foundation for MC array sensing. In the present work, we investigated the response consistency of MC array sensing. The responses of two types of commercially available MC arrays were studied under conditions of temperature change, solution replacement and biochemical molecular interaction. For the thermal response, the deflections of both arrays were found to be proportional to temperature, and the responses of the MCs in both arrays were consistent with each other. The thermal response sensitivity for each MC during temperature increase and decrease also showed good consistency. Moreover, the MC array showed good consistency for the response induced by solution replacement. Finally, we also demonstrated that the MC array had good consistency in biochemical detection, exemplified by aflatoxin antibody-anti gen binding. The good response consistency makes this technology reliable and accurate for biochemical sensing.展开更多
The bearing capacity of pile foundations is affected by the temperature of the frozen soil around pile foundations.The construction process and the hydration heat of cast-in-place(CIP)pile foundations affect the therm...The bearing capacity of pile foundations is affected by the temperature of the frozen soil around pile foundations.The construction process and the hydration heat of cast-in-place(CIP)pile foundations affect the thermal stability of permafrost.In this paper,temperature data from inside multiple CIP piles,borehole observations of ground thermal status adjacent to the foundations and local weather stations were monitored in warm permafrost regions to study the thermal influence process of CIP pile foundations.The following conclusions are drawn from the field observation data.(1)The early temperature change process of different CIP piles is different,and the differences gradually diminish over time.(2)The initial concrete temperature is linearly related with the air temperature,net radiation and wind speed within 1 h before the completion of concrete pouring;the contributions of the air temperature,net radiation,and wind speed to the initial concrete temperature are 51.9%,20.3%and 27.9%,respectively.(3)The outer boundary of the thermal disturbance annulus is approximately 2 m away from the pile center.It took more than 224 days for the soil around the CIP piles to return to the natural permafrost temperature at the study site.展开更多
基金The work was supported by the National Natural Science Foundation of China(No.51978627)the Natural Science Foundation of Zhejiang Province(No.Y19E080024).
文摘Research on the influence of thermal radiation of tree canopies to adjacent exterior walls has relevance to the selection of tree species and the spatial arrangement of trees for urban planning.In the last decade,there have been many studies on the influence of tree shadows on the thermal environment and energy consumption of buildings.However,there is a lack of research on how trees affect the thermal radiation of adjacent buildings,when they do not cast direct shadows on the walls.In view of this,a combination of experiment and simulation was used to explore the influence of spherical canopy on the intensity changes of net long-wave thermal radiation(T_(RDL))and net short-wave thermal radiation(T_(RDS))absorbed by the adjacent wall.Both measured and simulated results show that the tree canopy has a T_(RD)(the sum of T_(RDL) and T_(RDS))effect on the south wall of adjacent buildings in summer.The peak of T_(RD) from the tree to the adjacent wall was obtained by ENVI-met under 27 scenarios.A functional relationship was further given between the peak T_(RD) and the canopy diameter(D_(C)),the minimum distance between wall and tree canopy(D_(W-T)).Moreover,the influence of D_(C),D_(W-T) and leaf area density(LAD)on T_(RD) was discussed by simulation.Additionally,the Trd of canopy decays exponentially in the horizontal direction and linearly in the vertical direction of the wall.The above methods and results can guide the selection of tree species,green space design around buildings and the evaluation of the influence of trees on indoor cooling energy consumption in summer.
基金The authors are grateful to the financial support by Jiangsu Agriculture Science and Technology Innovation Fund(CX(16)1045)Key R&D programs of Jiangsu Province and Zhenjiang(BE2016354,NY20160120037)+1 种基金China and Jiangsu postdoctoral science foundations(2016M600376,1601032C)Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Confronted with severe frost damage to plants,methods,technologies and equipment have been developed and applied during the past century.The paper presents a comprehensive review on the most effective and active technology to protect plants from radiation frost based on air disturbance technology.The working principle of the technology was elaborated with frost protection mechanism,structures and applicability of three types of working patterns:conventional wind machines,selective inverted sink and portable vertical blowing.As an automatic mechanized technology,control strategy,applicable occasion and proper parameters are introduced for each type of working pattern.The operation of the technology and equipment depends on plant critical temperature,prevailing climatic conditions,thermal inversions strength,as well as costs.The frost protection performance and effectiveness of conventional horizontal wind machines,selective inverted sinks and helicopters are discussed and compared from the cost-effectiveness and application aspects,and the feasibility of selective inverted sinks is still controversial.Therefore,conventional wind machines are the best choice for plant frost protection and consequently are widely used in temperate and subtropical areas throughout the world.The frost protection application with helicopters is not easy to use during the frost nights with high cost.The paper also provides researchers with some perspectives on improving air disturbance technology and its equipment,and some practice recommendations for growers.
基金supported by the National Natural Science Foundation of China(Grant No.11502265)the Fundamental Research Funds for the Central Universities(Grant No.WK2480000002)
文摘Array sensing is increasingly important in the development of microcantilever(MC) sensors, and response consistency is the foundation for MC array sensing. In the present work, we investigated the response consistency of MC array sensing. The responses of two types of commercially available MC arrays were studied under conditions of temperature change, solution replacement and biochemical molecular interaction. For the thermal response, the deflections of both arrays were found to be proportional to temperature, and the responses of the MCs in both arrays were consistent with each other. The thermal response sensitivity for each MC during temperature increase and decrease also showed good consistency. Moreover, the MC array showed good consistency for the response induced by solution replacement. Finally, we also demonstrated that the MC array had good consistency in biochemical detection, exemplified by aflatoxin antibody-anti gen binding. The good response consistency makes this technology reliable and accurate for biochemical sensing.
基金supported by the Natural Science Foundation of China (Grants No.41101065)the State Key Laboratory of Frozen Soil Engineering Funds (SKLFSE-ZT-34,SKLFSE-ZQ-202103).
文摘The bearing capacity of pile foundations is affected by the temperature of the frozen soil around pile foundations.The construction process and the hydration heat of cast-in-place(CIP)pile foundations affect the thermal stability of permafrost.In this paper,temperature data from inside multiple CIP piles,borehole observations of ground thermal status adjacent to the foundations and local weather stations were monitored in warm permafrost regions to study the thermal influence process of CIP pile foundations.The following conclusions are drawn from the field observation data.(1)The early temperature change process of different CIP piles is different,and the differences gradually diminish over time.(2)The initial concrete temperature is linearly related with the air temperature,net radiation and wind speed within 1 h before the completion of concrete pouring;the contributions of the air temperature,net radiation,and wind speed to the initial concrete temperature are 51.9%,20.3%and 27.9%,respectively.(3)The outer boundary of the thermal disturbance annulus is approximately 2 m away from the pile center.It took more than 224 days for the soil around the CIP piles to return to the natural permafrost temperature at the study site.
