天津市近郊地表风蚀型开放源对中心城区影响估算研究

可吸入颗粒物(PM₁₀)是我国大部分城市环境空气的首要污染物,地表风蚀尘是其重要来源,需要对该源的贡献量进行定量估算.基于TM遥感影像对天津土地利用类型进行分类并在近郊布设94个点采集地表土壤样品,进行粒度分析,基于GIS进行克里格插值计算,得到土壤粒径分布.结合风向、风速等气象数据,计算得出2009年分季节近郊四区（北辰、西青、津南和东丽）土壤风蚀模数、风蚀量、释尘模数和释尘量.结果表明,天津市近郊春、夏、秋和冬的风蚀量分别为21236.31、 4435.21、 7272.13和17204.40 t;北辰、西青、津南和东丽的全年风蚀量分别为6380.23、 32881.13、 8340.67和2546.02 t;全年耕地和林草地的风蚀量分别为49 599.20和548.85 t.天津市近郊2009年释尘量分别为9352.92 t（粒径＜10 μm）、 20587.99 t（粒径10～15 μm）和13873.74 t（粒径15～20 μm）.天津市近郊输入中心城区20　μm以下的尘量为20592.91 t, 10 μm以下的尘量为4395.89 t,占21.35%.     

Impact of Covid-19 partial lockdown on PM2.5, SO2, NO2, O3, and trace elements in PM2.5 in Hanoi,Vietnam

Covid-19 lockdowns have improved the ambient air quality across the world via reduced air pollutant levels. This article aims to investigate the effect of the partial lockdown on the main ambient air pollutants and their elemental concentrations bound to PM_2.5 in Hanoi. In addition to the PM_2.5 samples collected at three urban sites in Hanoi, the daily PM_2.5, NO₂, O₃, and SO₂ levels were collected from the automatic ambient air quality monitoring station at Nguyen Van Cu street to analyze the pollution level before (March 10th–March 31st) and during the partial lockdown (April 1st–April 22nd) with “current” data obtained in 2020 and “historical” data obtained in 2014, 2016, and 2017. The results showed that NO₂, PM_2.5, O₃, and SO₂ concentrations obtained from the automatic ambient air quality monitoring station were reduced by 75.8, 55.9, 21.4, and 60.7%, respectively, compared with historical data. Besides, the concentration of PM_2.5 at sampling sites declined by 41.8% during the partial lockdown. Furthermore, there was a drastic negative relationship between the boundary layer height (BLH) and the daily mean PM_2.5 in Hanoi. The concentrations of Cd, Se, As, Sr, Ba, Cu, Mn, Pb, K, Zn, Ca, Al, and Mg during the partial lockdown were lower than those before the partial lockdown. The results of enrichment factor (EF) values and principal component analysis (PCA) concluded that trace elements in PM_2.5 before the partial lockdown were more affected by industrial activities than those during the partial lockdown.

     

Characteristics and Bioactivities of Carrageenan/Chitosan Microparticles Loading α-Mangostin

Journal of Polymers and the Environment - This study attempted to develop carrageenan/chitosan based microparticles loading α-mangostin which was extracted from Vietnamese mangosteen skin. The...     

农户对替代生计的选择及其影响因素分析——以甘南黄河水源补给区为例

论文通过实地调查获得研究数据,分析了农区、 半农半牧区、 纯牧区农户替代生计选择的结果及特征,采用Logistic回归模型对影响农户替代生计选择意愿的因素进行分析。研究得出:①在替代生计的选择上,纯牧区农户主要选择特色产品加工、 做生意、 现代畜牧业,农区和半农半牧区农户主要选择做生意、 外出打工和旅游服务业;②农户对替代生计的选择表现出生计路径依赖性、 区域差异性和多样性特征;③农户对替代生计的选择偏好受生计资本的影响,自然资本、 社会资本、 家庭整体劳动能力、 家庭整体受教育水平、 家庭拥有的牲畜数量、 户主的学历和年龄分别对不同替代生计的选择影响显著。地方政府应深入了解农户选择替代生计的特点和影响因素,根据不同家庭的情况设计相应的转型政策促进农户尽快提高生计能力。     

邻苯二甲酸酯类对水生食物链的影响研究进展

邻苯二甲酸酯类(PAEs)增塑剂被普遍用于塑料制品中,在大气、水等环境中广泛存在,其潜在危害受到关注。水环境中的PAEs,从藻类等初级生产者吸收,到浮游动物、游泳动物等通过鳃和皮肤直接接触或捕食摄取,在水生生物之间转化和传递。笔者总结了PAEs在水生食物链中不同营养级生物体的含量,分析了PAEs在食物链中富集和转化的影响因素(辛醇-水分配系数Kow、代谢转化、生长阶段等)。目前的研究表明PAEs可能在食物链中传递,最终在较高营养级生物体中富集。同时总结了5种PAEs(邻苯二甲酸二丁酯、邻苯二甲酸二乙酯、邻苯二甲酯丁苄酯、邻苯二甲酸二(2-乙基)己酯和邻苯二甲酸二甲酯)对水生生物的毒性效应的研究进展,已有研究表明PAEs对藻类的细胞器和抗氧化体系,对鱼类的生殖系统、内分泌系统和抗氧化体系都有一定程度损伤。PAEs在食物链中传递和富集现象的存在会对高营养级水生生物产生潜在危害。针对目前PAEs在食物链中传递的研究数量较少、结构简单等问题,对未来研究方向做了简要分析和展望。     

村域社会资本与环境影响的关系——基于甘肃省村域调查数据

社会资本作为改善生态环境的先决条件,已引起了全社会的广泛关注,当前急需辨明社会资本与环境影响之间的关系,并依次寻求解决生态环境问题的对策措施。研究基于甘肃省20个村域的调查数据,以网络、信任、规范为指标测度社会资本,以生态足迹为指标测度环境影响,利用计量经济模型分析了村域层面社会资本与环境影响的关系。结果表明:①社会资本差异有助于解释村域之间的环境影响差异;②社会资本的普遍信任维度、制度信任维度与环境影响呈显著正相关,规范维度与环境影响呈显著负相关,网络维度虽与环境影响呈负相关,但统计上不显著;③劳动力受教育程度、非农就业水平与环境影响呈显著负相关,人口规模虽与环境影响呈正相关,但在多数模型中不显著。最后,指出了社会资本对环境影响作用研究中需进一步关注的问题。     

Dissipation of polycyclic aromatic hydrocarbons and microbial activity in a field soil planted with perennial ryegrass

Dissipation and plant uptake of polycyclic aromatic hydrocarbons (PAHs) in contaminated agricultural soil planted with perennial ryegrass were investigated in a field experiment. After two seasons of grass cultivation the mean concentration of 12 PAHs in soil decreased by 23.4% compared with the initial soil. The 3-, 4-, 5-, and 6-ring PAHs were dissipated by 30.9%, 25.5%, 21.2%, and 16.3% from the soil, respectively. Ryegrass shoots accumulated about 280 μg·kg^-1, shoot dry matter biomass reached 2.48 × 10⁴ kg·ha^-1, and plant uptake accounted for about 0.99% of the decrease in PAHs in the soil. Significantly higher soil enzyme activities and microbial community functional diversity were observed in planted soil than that in the unplanted control. The results suggest that planting ryegrass may promote the dissipation of PAHs in long-term contaminated agricultural soil, and plant-promoted microbial degradation may be a main mechanism of phytoremediation.     

长期定位施肥下紫色土土壤微形态特征

通过对紫色土长期定位施肥下不同施肥处理0～20 cm耕层土壤微形态特征的研究,试图说明施肥对紫色土微形态的影响.用单偏光显微镜对不同处理的土壤微形态进行了观察与分析.结果表明:长期不施肥料的CK处理,土壤耕层结构致密,很少有孔隙发育,土壤微结构为结构较差的碎屑聚积状-沙粒聚积状;长期单施化学肥料,土壤颗粒未形成结构体,少孔隙,土壤微结构主要为斑晶胶凝状-细沙粒聚积状结构,土壤结构比CK处理优;长期施用有机肥或有机无机肥料配施的处理,土壤粗颗粒数量显著增加,结构疏松,孔隙量大,动、植物残体丰富,有铁锰结核和腐殖质的形成和微团聚体的发育,土壤微结构类型以MNPK处理最好,为胶凝紧实状-多孔状结构.有机无机肥料配施能显著改良紫色土的结构,培肥土壤,实现土壤可持续发展.     

Sea snakes anticipate tropical cyclone

Here, we report anticipatory behaviors of sea snakes and provide the first evidence for a sensory mechanism by which they survive a catastrophic cyclone. Sea kraits (Laticauda spp.) are normally abundant in littoral habitats at Lanyu (Orchid Island), Taiwan but disappeared coincident with falling barometric pressure prior to typhoon Morakot, which impacted the island severely during 7–9 August 2009. The abundance of sea kraits that are visible within the littoral zone correlates with barometric pressure, but not with precipitation or wind speed, which drives the surf. We found very little evidence of direct mortality caused by the storm, and the visible abundance of sea kraits following the storm returned to pre-storm levels. Data suggest that survival of sea kraits depends on the sensory perception of low pressures preceding a tropical cyclone, followed by behaviors which avoid the lethal storm energies potentially affecting this coastal population. Sea kraits likely find refuge in cavernous spaces beneath volcanic rocks of the seacoast.