Association between particulate matter air pollution and cardiovascular disease mortality in Lanzhou,China

Ambient particulate matter (PM) pollution has been linked to elevated mortality, especially from cardiovascular diseases. However, evidence on the effects of particulate matter pollution on cardiovascular mortality is still limited in Lanzhou, China. This research aimed to examine the associations of daily mean concentrations of ambient air pollutants (PM_2.5, PM_C, and PM₁₀) and cardiovascular mortality due to overall and cause-specific diseases in Lanzhou. Data representing daily cardiovascular mortality rates, meteorological factors (daily average temperature, daily average humidity, and atmospheric pressure), and air pollutants (PM_2.5, PM₁₀, SO₂, NO₂) were collected from January 1, 2014, to December 31, 2017, in Lanzhou. A quasi-Poisson regression model combined with a distributed lag non-linear model (DLNM) was used to estimate the associations. Stratified analyses were also performed by different cause-specific diseases, including cerebrovascular disease (CD), ischemic heart disease (IHD), heart rhythm disturbances (HRD), and heart failure (HF). The results showed that elevated concentration of PM_2.5, PM_C, and PM₁₀ had different effects on mortality of different cardiovascular diseases. Only cerebrovascular disease showed a significant positive association with elevated PM_2.5. Positive associations were identified between PM_C and daily mortality rates from total cardiovascular diseases, cerebrovascular diseases, and ischemic heart diseases. Besides, increased concentration of PM₁₀ was correlated with increased death of cerebrovascular diseases and ischemic heart diseases. For cerebrovascular disease, each 10 μg/m³ increase in PM_2.5 at lag4 was associated with increments of 1.22% (95% CI 0.11–2.35%). The largest significant effects for PM_C on cardiovascular diseases and ischemic heart diseases were both observed at lag0, and a 10 μg/m³ increment in concentration of PM_C was associated with 0.47% (95% CI 0.06–0.88%) and 0.85% (95% CI 0.18–1.52%) increases in cardiovascular mortality and ischemic heart diseases. In addition, it exhibited a lag effect on cerebrovascular mortality as well, which was most significant at lag6d, and an increase of 10 μg/m³ in PM_C was associated with a 0.76% (95% CI 0.16–1.37%) increase in cerebrovascular mortality. The estimates of percentage change in daily mortality rates per 10 μg/m³ increase in PM₁₀ were 0.52% (95% CI 0.05–1.02%) for cerebrovascular disease at lag6 and 0.53% (95% CI 0.01–1.05%) for ischemic heart disease at lag0, respectively. Our study suggests that elevated concentration of atmospheric PM (PM_2.5, PM_C, and PM₁₀) in Lanzhou is associated with increased mortality of cardiovascular diseases and that the health effect of elevated concentration of PM_2.5 is more significant than that of PM_C and PM₁₀.

     

真空紫外光-TiO2催化降解气态偏二甲肼

以钛箔为载体,采用溶胶-凝胶法及浸渍-烘焙-煅烧法制备了负载型TiO₂薄膜,并进行了SEM,EDS,XRD表征。探讨了TiO₂薄膜对气态偏二甲肼的光催化降解效果,并对比研究了不同紫外光源、不同初始浓度对气态偏二甲肼降解效果的影响。实验结果表明：TiO₂均匀负载在钛箔上且为多孔状的薄膜;偏二甲肼质量浓度为877 mg/m³时,反应17 min后偏二甲肼的降解率为99.99%,500 mg/m³时反应60 min后偏二甲肼的矿化率达到41.58%。     

基于城市大气挥发性有机物特征分析的数据质量评估方法及案例

城市大气挥发性有机物(VOCs)监测是空气质量监测网的重要组成部分,而数据质量控制和质量保证是VOCs监测的基础。基于8次中国城市大气VOCs外场监测,通过挖掘VOCs浓度、组成和化学活性的内在规律,对VOCs监测数据质量进行评估并总结方法。分析结果显示:城市大气乙烷和苯等长寿命组分具有明显的背景浓度,且区域背景值较为接近,可以用来诊断长寿命VOCs组分浓度异常偏低或偏高现象。而示踪组分的季节(日)变化规律可以用来识别VOCs组分定性问题(如夏季大气异戊二烯和烷基硝酸酯浓度日变化规律应反映植被排放和光化学反应特征)。另外,在气团混合均匀的情况下,VOCs浓度波动与其活性之间存在负相关,这一规律可以用来核查数据准确性或局地源影响。     

A bibliometric analysis of biodiesel research during 1991–2015

A bibliometric analysis based on the Science Citation Index Expanded (SCI-EXPANDED) from the Web of Science was carried out to provide insights into research activities and tendencies of the global biodiesel from 1991 to 2015. The document type and language, characteristics of publication outputs, Web of Science categories, journals, countries, institutions, author keyword and most cited articles were emphasized. The results indicated that annual output of the related scientific articles increased steadily. The top six categories focus on different aspects of biodiesel research. Bioresource Technology and Fuel were the two most frequent journals in the field of biodiesel research. The USA took a leading position and had the highest h-index (108) out of 122 countries/territories, followed by China and Brazil. Finally, author keywords and most cited articles were analyzed, indicating that microalgae, Jatropha curcas, vegetable oil and waste cooking oil are the most general raw materials for biodiesel production.     

三江源区径流退水过程演变规律

利用三江源区1960~2009年间的月径流数据,使用数字滤波法进行基流分割并使用Depuit-Boussinesq方程进行退水系数计算,同时对径流量、基流量、退水系数分别进行Mann-Kendall趋势检验。结果显示:(1)过去50 a间黄河与澜沧江年内径流量显著减少,而长江源区径流变化趋势不明显;(2)三江源区冬季枯水期径流量主要受基流控制,基流占冬季径流的比值最高可达100%,黄河源区与澜沧江源区过去50 a来基流在不断减少基流的变化趋势和突变点与径流呈现出高度一致;(3)在过去50 a,长江源区的年径流退水过程正在减缓,气候变化影响下,降雨是三江源区径流退水过程的主要影响因素,降雨量的增加会导致退水系数的减小,而温度对三江源区的退水过程影响存在着不确定性。研究为揭示气候变化下三江源区径流退水过程的演变过程提供了理论参考。     

升金湖湿地时空演变对越冬鹤类种群动态的影响

升金湖湿地是我国主要的鹤类越冬栖息地之一。研究升金湖湿地时空变化对越冬鹤类种群动态的影响在湿地生态环境改善、鹤类种群恢复等方面具有重要参考价值。对1986～2015年升金湖湿地白头鹤（Grus monacha）、白鹤（Grus leucogeranus）、灰鹤（Grus grus）及白枕鹤（Grus vipio）种群数量的变化趋势分别进行了曲线拟合;结合升金湖湿地1986~2015年间8期遥感影像分析了研究区土地利用/覆盖的时空变化;并探讨了湿地时空变化与越冬鹤类种群数量变化之间的相关性。结果表明：1986~2015年间,研究区的景观格局发生了较大变化,草地、水田、滩涂及其他用地的面积总体呈增加态势,而林地、旱地、水域及芦苇沼泽地面积总体呈减少的态势;4种鹤类的数量总体呈下降趋势,曲线拟合中白鹤和白枕鹤种群数量变化的趋势方程拟合度较高;芦苇沼泽地及水域面积变化与越冬鹤类种群数量呈显著的正相关关系,而草地、滩涂及水田的面积与鹤类种群数量呈较强的负相关关系;其他景观面积变化间接对鹤类种群数量产生影响。 关键词： 时空变化;鹤类;遥感影像;土地利用/覆盖;升金湖     

家长式领导对高速铁路司机安全行为的影响研究

为了进一步提升高速铁路司机的安全绩效,保证高速铁路的运输安全,以高速铁路司机为研究对象,利用国内11家铁路局的调研数据,构建理论模型,实证研究家长式领导风格对安全氛围及安全行为的影响,采用回归分析和Bootstrap技术进行检验。结果表明:德行领导、仁慈领导和威权领导均对高速铁路司机的安全行为产生显著正向影响;安全氛围在家长式领导风格与安全行为之间起到部分中介作用;德行领导和仁慈领导对安全行为具有正向交互影响效应。     

白马湖水污染特征及其成因分析

为揭示白马湖水污染特征及其成因,在历史监测数据收集的基础上,于2016年11月初对白马湖25个采样点的水质指标进行了分析。结果表明:近年来白马湖水质波动较大,2010~2014年期间,白马湖水体水质总体处于Ⅳ类;2015年好转为Ⅲ类;2016年又下降为Ⅴ类。白马湖水体富营养化综合指数(TLIc)呈显著增加趋势,由最初的轻度富营养化水平演变到目前的中度富营养化水平(TLIc:66.66)。采样期间,白马湖水体主要以氮污染物为主,其次是磷污染物和耗氧污染物。湖泊水体污染程度依次为:北部湖区东部和中部湖区南部湖区。湖水中总氮(TN)约83%以溶解性总氮(TDN)的形式存在,氨氮(NH+4-N)占TDN的65%,其次是NO3--N(25%);总磷(P)约60%以溶解性总磷(TDP)的形式存在,正磷酸盐(PO3-4-P)占TDP的55%左右。北部湖区TDN/TDP比值最高(50.51±19.16)(p0.05),P是北部湖区藻类生长的限制因子;中部、东部和南部湖区TDN/TDP比值均已适应藻类生长。陆域外源污染源输入是引起白马湖水质空间异质性和水质下降的主要因素,湖内水生植被消亡和水产养殖污染引起的生态功能退化也是造成白马湖水质下降的一个原因。研究可为当下白马湖水质演化研究及水环境治理提供新的理论基础。     

鄱阳湖出流水质2004~2014年变化及其对水位变化的响应:对水质监测频率的启示

通过对鄱阳湖湖口2004~2014年以周为单位的水质指标,包括溶解氧（DO）,氨氮（NH₄⁺-N）和高锰酸盐指数（COD_Mn）的变化特征及其与水位响应关系进行分析,并对合理的监测频率进行了探讨。结果表明：（1）就DO,NH₄⁺-N和COD_Mn而言,鄱阳湖出湖水质在2004~2014年没有显著恶化的趋势,然而在年内呈现明显的周期性变化,其浓度与湖泊水位波动有较显著的负相关性（p<0.01）,相关系数分别达到-0.63,-0.67和-0.36;（2）考虑水质指标在湖相状态与河相状态存在显著的差异（p<0.01）,概率密度分布曲线进一步表明,在鄱阳湖呈湖相时,湖口NH₄⁺-N浓度小于0.25 mg/L的概率为93%,而在河相时仅为32.8%。DO与COD_Mn浓度在河湖相的特征与NH₄⁺-N相似。因此,在湖相状态下,鄱阳湖出流水质良好的概率更大,而高水位下的稀释作用可能是影响湖泊年内变化的主要控制因素;（3）时间序列分析表明DO,NH₄⁺-N和COD_Mn存在明显的自相关性,1~2月一次的监测频率基本能够准确的描述NH₄⁺-N和DO的动态变化特征,而COD_Mn仍需要1~2周一次的监测,从而避免过多的损失动态信息。能够为将来更深入的研究湖泊水情与水质定量关系提供基础和思路,从而为湖泊水环境管理和调控提供对策和建议。     

基于GIS和RUSLE模型的万州区土壤保持服务功能空间分布特征

土壤保持服务是重要的生态系统服务之一,代表生态系统对土壤侵蚀所起到的削减和改善作用。以万州为研究区,基于GIS平台和修正通用土壤流失方程(RUSLE),运用降雨、DEM等数据建模,探讨万州区土壤保持服务功能的空间分布特征并分析其影响因素。结果显示:(1)万州区土壤保持总量为1 435.84×10~5t/a,单位面积年均土壤保持量为417.91 t/(hm~2·a),具有较高的土壤保持服务功能重要性;(2)土壤保持服务空间分布受地形和人类活动等的显著影响,东南部山地区域较高,而铁峰山与方斗山之间的长江河谷较低,其空间分布特征与土壤侵蚀的分布状况大致相反;(3)坡度角度,15°~25°坡度区产沙量最大占全区的41.56%,8°~15°区域次之,这两个坡度区人地矛盾最为集中;土地利用类型中,旱地侵蚀最为强烈,而林地侵蚀微弱并表现出很高的土壤保持服务功能。研究结果对万州乃至整个三峡库区的水土保持工作有借鉴意义。