随着全球气候变暖,气温上升,佩戴安全头盔的户外作业人员的热舒适度大幅下降,还将伴随着中暑、脱水等健康问题。现有的安全头盔有加强自然对流、强制对流、加装制冷设备等三种途径实现降温,然而会牺牲安全头盔的安全性能、增加头盔负重...随着全球气候变暖,气温上升,佩戴安全头盔的户外作业人员的热舒适度大幅下降,还将伴随着中暑、脱水等健康问题。现有的安全头盔有加强自然对流、强制对流、加装制冷设备等三种途径实现降温,然而会牺牲安全头盔的安全性能、增加头盔负重,各有缺陷。文章提出一种涂敷了被动辐射制冷涂层的安全头盔,可低成本地实现安全头盔的降温性能,提高佩戴人员的热舒适度。经实验测试,涂层附着能力强;涂敷了被动辐射制冷涂层的安全头盔的安全性能未受到损伤,符合相关安全标准;在户外时,涂敷了被动辐射制冷涂层的安全头盔比未处理的安全头盔外表面温度平均降低了10℃以上,内部温度平均降低了3℃以上。被动辐射制冷涂层对安全头盔具有显著的降温效果。With global climate change and rising temperatures, the thermal comfort of outdoor workers wearing safety helmets has significantly decreased, accompanied by health problems such as heatstroke and dehydration. The existing safety helmets have three ways to achieve cooling: strengthening natural convection, forced convection, and installing refrigeration equipment. However, in this case, the safety performance of the helmet will be reduced, and the weight of the helmet will be increased. These three ways have their own shortcomings. This article proposes a safety helmet coated with passive radiation cooling coating, which can achieve the cooling performance of the safety helmet at a low cost and improve the thermal comfort of the wearer. Through experimental testing, the coating has strong adhesion ability. The safety performance of the helmet coated with passive radiation cooling coating has not been damaged and meets relevant safety standards. In outdoor testing, the safety helmets coated with passive radiation cooling have an average surface temperature reduction of more than 10˚C and an average internal temperature reduction of more than 3˚C compared to untreated safety helmets. Passive radiation cooling coating has a significant cooling effect on safety helmets.展开更多
针对湖南省的带外源输入的非线性自回归(Nonlinear autoregressive with external input,NARX)神经网络模型,评估了2019年10月1日-2020年9月30日的污染物浓度预报准确率,并进一步评估模式对O_(3)和PM_(2.5)等两个重点污染物的时空分布...针对湖南省的带外源输入的非线性自回归(Nonlinear autoregressive with external input,NARX)神经网络模型,评估了2019年10月1日-2020年9月30日的污染物浓度预报准确率,并进一步评估模式对O_(3)和PM_(2.5)等两个重点污染物的时空分布预报效果。结果表明:模式预报的未来第1天级别准确率为91%,首要污染物准确率为70%;在空气质量等级为优良时,其预报能力较好。从时间序列上看,模式预报的PM和臭氧日最大8小时滑动平均浓度(O_(3)_8hr)与实测浓度的变化趋势较为一致,但模式对PM浓度有所高估;从空间分布上看,模式对夏季和冬季O_(3)_8hr整体的空间分布预报能力较优,且能够捕捉冬季PM污染过程的发生。展开更多
文摘随着全球气候变暖,气温上升,佩戴安全头盔的户外作业人员的热舒适度大幅下降,还将伴随着中暑、脱水等健康问题。现有的安全头盔有加强自然对流、强制对流、加装制冷设备等三种途径实现降温,然而会牺牲安全头盔的安全性能、增加头盔负重,各有缺陷。文章提出一种涂敷了被动辐射制冷涂层的安全头盔,可低成本地实现安全头盔的降温性能,提高佩戴人员的热舒适度。经实验测试,涂层附着能力强;涂敷了被动辐射制冷涂层的安全头盔的安全性能未受到损伤,符合相关安全标准;在户外时,涂敷了被动辐射制冷涂层的安全头盔比未处理的安全头盔外表面温度平均降低了10℃以上,内部温度平均降低了3℃以上。被动辐射制冷涂层对安全头盔具有显著的降温效果。With global climate change and rising temperatures, the thermal comfort of outdoor workers wearing safety helmets has significantly decreased, accompanied by health problems such as heatstroke and dehydration. The existing safety helmets have three ways to achieve cooling: strengthening natural convection, forced convection, and installing refrigeration equipment. However, in this case, the safety performance of the helmet will be reduced, and the weight of the helmet will be increased. These three ways have their own shortcomings. This article proposes a safety helmet coated with passive radiation cooling coating, which can achieve the cooling performance of the safety helmet at a low cost and improve the thermal comfort of the wearer. Through experimental testing, the coating has strong adhesion ability. The safety performance of the helmet coated with passive radiation cooling coating has not been damaged and meets relevant safety standards. In outdoor testing, the safety helmets coated with passive radiation cooling have an average surface temperature reduction of more than 10˚C and an average internal temperature reduction of more than 3˚C compared to untreated safety helmets. Passive radiation cooling coating has a significant cooling effect on safety helmets.
文摘针对湖南省的带外源输入的非线性自回归(Nonlinear autoregressive with external input,NARX)神经网络模型,评估了2019年10月1日-2020年9月30日的污染物浓度预报准确率,并进一步评估模式对O_(3)和PM_(2.5)等两个重点污染物的时空分布预报效果。结果表明:模式预报的未来第1天级别准确率为91%,首要污染物准确率为70%;在空气质量等级为优良时,其预报能力较好。从时间序列上看,模式预报的PM和臭氧日最大8小时滑动平均浓度(O_(3)_8hr)与实测浓度的变化趋势较为一致,但模式对PM浓度有所高估;从空间分布上看,模式对夏季和冬季O_(3)_8hr整体的空间分布预报能力较优,且能够捕捉冬季PM污染过程的发生。
