Objective Studies of the association of hypertension with long-term exposure to particulate matter less than 2.5μm in diameter(PM2.5)have shown contradictory results and the magnitude of the association is still uncl...Objective Studies of the association of hypertension with long-term exposure to particulate matter less than 2.5μm in diameter(PM2.5)have shown contradictory results and the magnitude of the association is still unclear.Hence,we conducted a meta-analysis of cohort studies to assess the effect of long-term exposure to PM2.5 on incident hypertension.展开更多
Objective Air pollution is an important risk factor for cardiovascular diseases throughout the world.Fine particulate matter(PM)air pollution alone is responsible for over three million deaths each year.Large and grow...Objective Air pollution is an important risk factor for cardiovascular diseases throughout the world.Fine particulate matter(PM)air pollution alone is responsible for over three million deaths each year.Large and growing literature has explored whether short-term exposure to fine particulate matter is associated with stroke,but results from prior studies have been inconsistent.To fill this gap,we assessed the evidence quantitatively from epidemiological time-series studies published worldwide and determined whether short-term exposure to fine particulate matter(<2.5μm or<10μm)diameter[PM2.5 and PM10]was associated with increased risk of hospital admission for stroke(including ischemic and hemorrhagic stroke).展开更多
In order to reveal the mechanics of composite regeneration by coupling cerium-based additive and microwave for a diesel particulate filter, a composite regeneration model by coupling cerium-based additive and microwav...In order to reveal the mechanics of composite regeneration by coupling cerium-based additive and microwave for a diesel particulate filter, a composite regeneration model by coupling cerium-based additive and microwave for a diesel particulate filter was established based on field synergy theory. Performance evaluation on field synergy and composite regeneration of the diesel particulate filter was conducted by using the vortex crushing combustion and field synergy mathematical models. The results show that the peak temperature of the particulate filter body reaches 1180-1190 K when the regeneration time is 175 s, and there are optimal coordination degree between the velocity vector and temperature gradient of the filter body and the maximum ratio0.56-0.60 of the best burning regeneration region is obtained. Accordingly, the largest regeneration combustion rate inside the particulate filter body and the highest regeneration efficiency at the moment are achieved.展开更多
为探究城市带状绿地降减空气颗粒物的作用机制和效应,选取武汉市罗家港带状公园绿地及其周边建成环境作为研究对象,选择冬季天气晴朗无风且气象条件相似的3天进行重复观测,采用土地利用回归(land use regression,LUR)模型和主成分分析...为探究城市带状绿地降减空气颗粒物的作用机制和效应,选取武汉市罗家港带状公园绿地及其周边建成环境作为研究对象,选择冬季天气晴朗无风且气象条件相似的3天进行重复观测,采用土地利用回归(land use regression,LUR)模型和主成分分析相结合的方法,分析冬季城市带状绿地对空气PM_(10)和PM_(2.5)质量浓度的降减效应,识别其关键影响因素。结果显示,基于LUR模型得出城市带状绿地对空气PM_(10)和PM_(2.5)的降减作用存在宽度效应,宽度30~40 m的绿地在冬季对空气PM_(10)的降减效率最显著。同时,研究发现冬季城市带状绿地内部的空气PM_(2.5)和PM_(10)质量浓度会出现高于邻近道路位置的现象,空气PM_(10)和PM_(2.5)在城市带状绿地内存在明显的积聚效应。结果表明,城市带状绿地对空气PM_(10)和PM_(2.5)的降减作用会受到周边交通污染排放的干扰,不同宽度带状绿地创造的微气象条件也会对空气PM_(10)和PM_(2.5)的质量浓度产生一定影响。展开更多
文摘Objective Studies of the association of hypertension with long-term exposure to particulate matter less than 2.5μm in diameter(PM2.5)have shown contradictory results and the magnitude of the association is still unclear.Hence,we conducted a meta-analysis of cohort studies to assess the effect of long-term exposure to PM2.5 on incident hypertension.
文摘Objective Air pollution is an important risk factor for cardiovascular diseases throughout the world.Fine particulate matter(PM)air pollution alone is responsible for over three million deaths each year.Large and growing literature has explored whether short-term exposure to fine particulate matter is associated with stroke,but results from prior studies have been inconsistent.To fill this gap,we assessed the evidence quantitatively from epidemiological time-series studies published worldwide and determined whether short-term exposure to fine particulate matter(<2.5μm or<10μm)diameter[PM2.5 and PM10]was associated with increased risk of hospital admission for stroke(including ischemic and hemorrhagic stroke).
基金Projects(51176045,51276056)supported by the National Natural Science Foundation of ChinaProject(531105050037)supported by the Changjiang Scholars and Innovative Research Team in University,ChinaProjects(201208430262,201306130031)supported by the National Studying Abroad Foundation Project of China
文摘In order to reveal the mechanics of composite regeneration by coupling cerium-based additive and microwave for a diesel particulate filter, a composite regeneration model by coupling cerium-based additive and microwave for a diesel particulate filter was established based on field synergy theory. Performance evaluation on field synergy and composite regeneration of the diesel particulate filter was conducted by using the vortex crushing combustion and field synergy mathematical models. The results show that the peak temperature of the particulate filter body reaches 1180-1190 K when the regeneration time is 175 s, and there are optimal coordination degree between the velocity vector and temperature gradient of the filter body and the maximum ratio0.56-0.60 of the best burning regeneration region is obtained. Accordingly, the largest regeneration combustion rate inside the particulate filter body and the highest regeneration efficiency at the moment are achieved.
文摘为探究城市带状绿地降减空气颗粒物的作用机制和效应,选取武汉市罗家港带状公园绿地及其周边建成环境作为研究对象,选择冬季天气晴朗无风且气象条件相似的3天进行重复观测,采用土地利用回归(land use regression,LUR)模型和主成分分析相结合的方法,分析冬季城市带状绿地对空气PM_(10)和PM_(2.5)质量浓度的降减效应,识别其关键影响因素。结果显示,基于LUR模型得出城市带状绿地对空气PM_(10)和PM_(2.5)的降减作用存在宽度效应,宽度30~40 m的绿地在冬季对空气PM_(10)的降减效率最显著。同时,研究发现冬季城市带状绿地内部的空气PM_(2.5)和PM_(10)质量浓度会出现高于邻近道路位置的现象,空气PM_(10)和PM_(2.5)在城市带状绿地内存在明显的积聚效应。结果表明,城市带状绿地对空气PM_(10)和PM_(2.5)的降减作用会受到周边交通污染排放的干扰,不同宽度带状绿地创造的微气象条件也会对空气PM_(10)和PM_(2.5)的质量浓度产生一定影响。
