为提高电磁辐射环境影响评价的科学性和准确性,考虑大型辐射源附近建筑物群对电磁环境的影响编制了电磁环境预测软件。提出计算建筑物群对射线产生单纯性多次反射时反射点通用算法、单纯性多次绕射时绕射点通用算法,将混合型路径转换成...为提高电磁辐射环境影响评价的科学性和准确性,考虑大型辐射源附近建筑物群对电磁环境的影响编制了电磁环境预测软件。提出计算建筑物群对射线产生单纯性多次反射时反射点通用算法、单纯性多次绕射时绕射点通用算法,将混合型路径转换成单纯型绕射路径的算法。将这些算法运用于角度z缓存区改进算法中,并采用场强精确算法编制程序。用该程序分别对两个通信基站、一个电视发射塔周边环境进行预测,预测结果与实测结果之间误差小于4 d B。说明该程序可以用于电磁环境影响评价。展开更多
Three-dimensional numerical simulations for a solar chimney power plant(SCPP)and wind supercharged solar chimney power plant(WSSCPP)based on the Spanish prototype using the solar ray-tracing algorithm were performed t...Three-dimensional numerical simulations for a solar chimney power plant(SCPP)and wind supercharged solar chimney power plant(WSSCPP)based on the Spanish prototype using the solar ray-tracing algorithm were performed to study the shadow effect of the chimney.The area of the shadow region increases with an increase in the incident angle of the solar rays.A parametric study was performed by varying the incident angle from 0°to 30°.The temperature and velocity distributions at different incident angles were analyzed.In addition,we investigated the chimney shadow effect in several comprehensive SCPP systems.The findings show that the turbine shaft powers of the SCPP and WSSCPP were reduced by 22.4%and 13.7%,respectively,when the incident angle increased from 0°to 30°.In conclusion,it is important to consider the chimney shadow effect when estimating the performance in the design and cost analysis of SCPP systems.展开更多
Canopy photosynthesis,rather than leaf photosynthesis,is highly related to plant biomass and yield formation.Studying canopy photosynthesis and identifying the parameters that control it can help optimize agricultural...Canopy photosynthesis,rather than leaf photosynthesis,is highly related to plant biomass and yield formation.Studying canopy photosynthesis and identifying the parameters that control it can help optimize agricultural management and achieve crop yield potential.Compared with traditional parameters,canopy occupation volume(COV)offers an integrative parameter on canopy architecture related to canopy photosynthetic rates.In this study,we developed a high-throughput method to derive COV for different rice varieties.We first used multi-perspective two-dimensional imaging to reconstruct three-dimensional point clouds of rice plants and developed a suite of pipelines to calculate plant height,leaf number,tiller number,and biomass,with R^(2) values of 91.8%,95.9%,82.3%,and 94.3%,respectively.We further employed point cloud data to reconstruct the surfaces of rice plants and construct a virtual canopy model of the rice population.Light distribution was simulated using a ray-tracing algorithm and canopy photosynthetic rates were simulated via photosynthetic rate-incident light intensity curve fitting.Furthermore,we systematically explored the relationships between canopy phenotypes and photosynthetic rates,and found that COV was the most effective predictor of canopy photosynthesis,achieving an R^(2) value of 92.1%.Adjustment in atmospheric transmittance showed that COV strongly correlated with canopy photosynthesis under different light conditions,with higher accuracy observed under diffuse light.Variations in planting density confirmed that this correlation remained strong at the community level.In summary,this study demonstrates that COV is closely linked to simulated canopy photosynthesis and the developed pipeline can support future agronomic and breeding research.展开更多
文摘为提高电磁辐射环境影响评价的科学性和准确性,考虑大型辐射源附近建筑物群对电磁环境的影响编制了电磁环境预测软件。提出计算建筑物群对射线产生单纯性多次反射时反射点通用算法、单纯性多次绕射时绕射点通用算法,将混合型路径转换成单纯型绕射路径的算法。将这些算法运用于角度z缓存区改进算法中,并采用场强精确算法编制程序。用该程序分别对两个通信基站、一个电视发射塔周边环境进行预测,预测结果与实测结果之间误差小于4 d B。说明该程序可以用于电磁环境影响评价。
基金the National Natural Science Foundation of China(No.51976053)College Students Innovation and Entrepreneurship Training Program(No.202010294024).
文摘Three-dimensional numerical simulations for a solar chimney power plant(SCPP)and wind supercharged solar chimney power plant(WSSCPP)based on the Spanish prototype using the solar ray-tracing algorithm were performed to study the shadow effect of the chimney.The area of the shadow region increases with an increase in the incident angle of the solar rays.A parametric study was performed by varying the incident angle from 0°to 30°.The temperature and velocity distributions at different incident angles were analyzed.In addition,we investigated the chimney shadow effect in several comprehensive SCPP systems.The findings show that the turbine shaft powers of the SCPP and WSSCPP were reduced by 22.4%and 13.7%,respectively,when the incident angle increased from 0°to 30°.In conclusion,it is important to consider the chimney shadow effect when estimating the performance in the design and cost analysis of SCPP systems.
基金supported by the National Natural Science Foundation of China(Grant Nos.32201654 and U22A20464)National Key Research and Development Program from the Ministry of Science and Technology of China(Grant No.2020YFA0907600)the 2115 Talent Development Program of China Agricultural University.
文摘Canopy photosynthesis,rather than leaf photosynthesis,is highly related to plant biomass and yield formation.Studying canopy photosynthesis and identifying the parameters that control it can help optimize agricultural management and achieve crop yield potential.Compared with traditional parameters,canopy occupation volume(COV)offers an integrative parameter on canopy architecture related to canopy photosynthetic rates.In this study,we developed a high-throughput method to derive COV for different rice varieties.We first used multi-perspective two-dimensional imaging to reconstruct three-dimensional point clouds of rice plants and developed a suite of pipelines to calculate plant height,leaf number,tiller number,and biomass,with R^(2) values of 91.8%,95.9%,82.3%,and 94.3%,respectively.We further employed point cloud data to reconstruct the surfaces of rice plants and construct a virtual canopy model of the rice population.Light distribution was simulated using a ray-tracing algorithm and canopy photosynthetic rates were simulated via photosynthetic rate-incident light intensity curve fitting.Furthermore,we systematically explored the relationships between canopy phenotypes and photosynthetic rates,and found that COV was the most effective predictor of canopy photosynthesis,achieving an R^(2) value of 92.1%.Adjustment in atmospheric transmittance showed that COV strongly correlated with canopy photosynthesis under different light conditions,with higher accuracy observed under diffuse light.Variations in planting density confirmed that this correlation remained strong at the community level.In summary,this study demonstrates that COV is closely linked to simulated canopy photosynthesis and the developed pipeline can support future agronomic and breeding research.
