利用动力学通量箱与高时间分辨率测汞仪联用技术对贵阳市市区及其郊区4个点的土壤大气界面间的汞交换通量进行了测定,用小型多功能气象仪记录了采样期间的气象参数。结果显示:4个采样点的大气汞含量都明显高于全球背景值(1.5~2.0 ng m-...利用动力学通量箱与高时间分辨率测汞仪联用技术对贵阳市市区及其郊区4个点的土壤大气界面间的汞交换通量进行了测定,用小型多功能气象仪记录了采样期间的气象参数。结果显示:4个采样点的大气汞含量都明显高于全球背景值(1.5~2.0 ng m-3),显示出贵阳市市区及郊区都遭受了不同程度的大气汞污染。土壤大气界面间的汞交换通量与光照强度具有显著的相关关系,与土壤温度也有很好的相关性。展开更多
The sinks/sources of carbon in the Yellow Sea(YS) and East China Sea(ECS), which are important continental shelf seas in China, could exert a great influence on coastal ecosystem dynamics and the regional climate chan...The sinks/sources of carbon in the Yellow Sea(YS) and East China Sea(ECS), which are important continental shelf seas in China, could exert a great influence on coastal ecosystem dynamics and the regional climate change process. The CO_2 exchange process across the seawater-air interface, dissolved and particulate carbon in seawater, and carbon burial in sediments were studied to understand the sinks/sources of carbon in the continental shelf seas of China. The YS and the ECS generally have different patterns of seasonal air-sea CO_2 exchange. In the YS, regions west of 124°E can absorb CO_2 from the atmosphere during spring and winter, and release CO_2 to the atmosphere during summer and autumn. The entire YS is considered as a CO_2 source throughout the year with respect to the atmosphere, but there are still uncertainties regarding the exact air-sea CO_2 exchange flux. Surface temperature and phytoplankton production were the key controlling factors of the air-sea CO_2 exchange flux in the offshore region and nearshore region of the YS, respectively. The ECS can absorb CO_2 during spring, summer, and winter and release CO_2 to the atmosphere during autumn. The annual average exchange rate in the ECS was-4.2±3.2 mmol m^(-2) d^(-1) and it served as an obvious sink for atmospheric CO_2 with an air-sea exchange flux of 13.7×10~6 t. The controlling factors of the air-sea CO_2 exchange in the ECS varied significantly seasonally. Storage of dissolved inorganic carbon(DIC) and dissolved organic carbon(DOC) in the YS and the ECS were 425×10~6 t and 1364×10~6 t, and 28.2×10~6 t and 54.1×10~6 t,respectively. Long-term observation showed that the DOC content in the YS had a decreasing trend, indicating that the "practical carbon sink" in the YS was decreasing. The total amount of particulate organic carbon(POC) stored in the YS and ECS was10.6×10~6 t, which was comparable to the air-sea CO_2 flux in these two continental shelf seas. The amounts of carbon sequestered by phytoplankton in the YS and the ECS were 60.4展开更多
In recent years,rapid urban development has led to capsule hotels,sleep pods,and other tiny sleeping spaces that adapt to people’s fast-paced lives,achieving maximum functionality with a very small footprint.However,...In recent years,rapid urban development has led to capsule hotels,sleep pods,and other tiny sleeping spaces that adapt to people’s fast-paced lives,achieving maximum functionality with a very small footprint.However,due to the small space,human metabolic pollutant(such as CO_(2))is more likely to accumulate,and the air is not easily circulated.In this paper,a full-size experimental platform is set up with three types of ventilation modes to explore the exclusion efficiency of metabolic pollutants and the overall distribution of age of air under these ventilation modes.The conclusions showed that the mean values of metabolic pollutant exclusion rates for the different ventilation modalities varied very little across the spatial dimensions of the confined space but varied considerably in the area around the head.The double-side attached ventilation method was the most effective in removing human metabolic pollutants,especially in the head region(CN≥0.92),while the single-wall attached ventilation method had the best air exchange efficiency(η≥0.85).This suggests an inconsistent distribution of CO_(2) and age of air,which is contrary to general common sense.The conclusions of this paper can guide the design of ventilation for tiny sleeping spaces.展开更多
Objective:To explore the reduction effect for the indoor ^(222)Rn(Rn)by Fresh Air Ventilation(FAV)system,a novel commercial ventilation device in China.Methods:The indoor concentrations of Rn and its decay products(Rn...Objective:To explore the reduction effect for the indoor ^(222)Rn(Rn)by Fresh Air Ventilation(FAV)system,a novel commercial ventilation device in China.Methods:The indoor concentrations of Rn and its decay products(RnD)in three residential rooms,two in Beijing and one in Hefei city,Anhui province,before and after FAVS functioned were measured using an active continuous method.The air exchange rate was monitored by measuring CO_(2) concentration using the tracer gas method.Results:In the three rooms,the FAVS reduced the Rn concentrations from(162±80)Bq/m^(3) to(63±22)Bq/m^(3) and decreased the RnD concentrations from(64±35)Bq/m^(3) to(13±6)Bq/m^(3) on average,a decrease of(59±25)% in the Rn concentrations and a drop of(77±18)%in the RnD concentrations.Considering dose conversion factors of Rn and RnD,FAVS decreased the exposure dose by(76±20)%.Besides,FAVS increased the air exchange rates from 0.17 h^(-1) to 0.56 h^(-1) on average.Conclusions:FAVS can effectively reduce indoor Rn and RnD concentrations by improving the air exchange,serving as a valuable supplement to existing radon mitigation methods,especially in extreme climates.展开更多
Partial pressure of CO2(pCO2) was investigated in the Changjiang(Yangtze River) Estuary,Hangzhou Bay and their adjacent areas during a cruise in August 2004,China.The data show that pCO2 in surface waters of the studi...Partial pressure of CO2(pCO2) was investigated in the Changjiang(Yangtze River) Estuary,Hangzhou Bay and their adjacent areas during a cruise in August 2004,China.The data show that pCO2 in surface waters of the studied area was higher than that in the atmosphere with only exception of a patch east of Zhoushan Archipelago.The pCO2 varied from 168 to 2 264 μatm,which fell in the low range compared with those of other estuaries in the world.The calculated sea-air CO2 fluxes decreased offshore and varied from -10.0 to 88.1 mmol m-2 d-1 in average of 24.4 ± 16.5 mmol m-2 d-1.Although the area studied was estimated only 2 × 104 km2,it emitted(5.9 ± 4.0) × 103 tons of carbon to the atmosphere every day.The estuaries and their plumes must be further studied for better understanding the role of coastal seas playing in the global oceanic carbon cycle.展开更多
文摘利用动力学通量箱与高时间分辨率测汞仪联用技术对贵阳市市区及其郊区4个点的土壤大气界面间的汞交换通量进行了测定,用小型多功能气象仪记录了采样期间的气象参数。结果显示:4个采样点的大气汞含量都明显高于全球背景值(1.5~2.0 ng m-3),显示出贵阳市市区及郊区都遭受了不同程度的大气汞污染。土壤大气界面间的汞交换通量与光照强度具有显著的相关关系,与土壤温度也有很好的相关性。
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA11020102)the Joint Fund between the National Natural Science Foundation of China and Shandong Province (Grant No. U1606404)the Program for Aoshan Excellent Scholars of Qingdao National Laboratory for Marine Science and Technology (Grant No. 013ASTP-OS13)
文摘The sinks/sources of carbon in the Yellow Sea(YS) and East China Sea(ECS), which are important continental shelf seas in China, could exert a great influence on coastal ecosystem dynamics and the regional climate change process. The CO_2 exchange process across the seawater-air interface, dissolved and particulate carbon in seawater, and carbon burial in sediments were studied to understand the sinks/sources of carbon in the continental shelf seas of China. The YS and the ECS generally have different patterns of seasonal air-sea CO_2 exchange. In the YS, regions west of 124°E can absorb CO_2 from the atmosphere during spring and winter, and release CO_2 to the atmosphere during summer and autumn. The entire YS is considered as a CO_2 source throughout the year with respect to the atmosphere, but there are still uncertainties regarding the exact air-sea CO_2 exchange flux. Surface temperature and phytoplankton production were the key controlling factors of the air-sea CO_2 exchange flux in the offshore region and nearshore region of the YS, respectively. The ECS can absorb CO_2 during spring, summer, and winter and release CO_2 to the atmosphere during autumn. The annual average exchange rate in the ECS was-4.2±3.2 mmol m^(-2) d^(-1) and it served as an obvious sink for atmospheric CO_2 with an air-sea exchange flux of 13.7×10~6 t. The controlling factors of the air-sea CO_2 exchange in the ECS varied significantly seasonally. Storage of dissolved inorganic carbon(DIC) and dissolved organic carbon(DOC) in the YS and the ECS were 425×10~6 t and 1364×10~6 t, and 28.2×10~6 t and 54.1×10~6 t,respectively. Long-term observation showed that the DOC content in the YS had a decreasing trend, indicating that the "practical carbon sink" in the YS was decreasing. The total amount of particulate organic carbon(POC) stored in the YS and ECS was10.6×10~6 t, which was comparable to the air-sea CO_2 flux in these two continental shelf seas. The amounts of carbon sequestered by phytoplankton in the YS and the ECS were 60.4
基金This study was jointly funded by Shaanxi Provincial Overseas Scholars Scientific and Technological Activities Selection Project(2022-005)Shaanxi Provincial Key R&D Program International Science and Technology Cooperation Program Project(2023-GHZD-28),and The Youth Innovation Team of Shaanxi Universities.
文摘In recent years,rapid urban development has led to capsule hotels,sleep pods,and other tiny sleeping spaces that adapt to people’s fast-paced lives,achieving maximum functionality with a very small footprint.However,due to the small space,human metabolic pollutant(such as CO_(2))is more likely to accumulate,and the air is not easily circulated.In this paper,a full-size experimental platform is set up with three types of ventilation modes to explore the exclusion efficiency of metabolic pollutants and the overall distribution of age of air under these ventilation modes.The conclusions showed that the mean values of metabolic pollutant exclusion rates for the different ventilation modalities varied very little across the spatial dimensions of the confined space but varied considerably in the area around the head.The double-side attached ventilation method was the most effective in removing human metabolic pollutants,especially in the head region(CN≥0.92),while the single-wall attached ventilation method had the best air exchange efficiency(η≥0.85).This suggests an inconsistent distribution of CO_(2) and age of air,which is contrary to general common sense.The conclusions of this paper can guide the design of ventilation for tiny sleeping spaces.
文摘Objective:To explore the reduction effect for the indoor ^(222)Rn(Rn)by Fresh Air Ventilation(FAV)system,a novel commercial ventilation device in China.Methods:The indoor concentrations of Rn and its decay products(RnD)in three residential rooms,two in Beijing and one in Hefei city,Anhui province,before and after FAVS functioned were measured using an active continuous method.The air exchange rate was monitored by measuring CO_(2) concentration using the tracer gas method.Results:In the three rooms,the FAVS reduced the Rn concentrations from(162±80)Bq/m^(3) to(63±22)Bq/m^(3) and decreased the RnD concentrations from(64±35)Bq/m^(3) to(13±6)Bq/m^(3) on average,a decrease of(59±25)% in the Rn concentrations and a drop of(77±18)%in the RnD concentrations.Considering dose conversion factors of Rn and RnD,FAVS decreased the exposure dose by(76±20)%.Besides,FAVS increased the air exchange rates from 0.17 h^(-1) to 0.56 h^(-1) on average.Conclusions:FAVS can effectively reduce indoor Rn and RnD concentrations by improving the air exchange,serving as a valuable supplement to existing radon mitigation methods,especially in extreme climates.
基金Supported by the National Basic Research Program of China (973 Program, No. 2005CB407305)the open foundation of the Key Laboratory of Marine Sedimentology & Environmental Geology, SOA (No. MASEG200606)+1 种基金the Qingdao Special Program for Leading Scientists (No. 05-2-JC-90)the 100-Talent Project of the Chinese Academy of Sciences
文摘Partial pressure of CO2(pCO2) was investigated in the Changjiang(Yangtze River) Estuary,Hangzhou Bay and their adjacent areas during a cruise in August 2004,China.The data show that pCO2 in surface waters of the studied area was higher than that in the atmosphere with only exception of a patch east of Zhoushan Archipelago.The pCO2 varied from 168 to 2 264 μatm,which fell in the low range compared with those of other estuaries in the world.The calculated sea-air CO2 fluxes decreased offshore and varied from -10.0 to 88.1 mmol m-2 d-1 in average of 24.4 ± 16.5 mmol m-2 d-1.Although the area studied was estimated only 2 × 104 km2,it emitted(5.9 ± 4.0) × 103 tons of carbon to the atmosphere every day.The estuaries and their plumes must be further studied for better understanding the role of coastal seas playing in the global oceanic carbon cycle.
