球形陶粒滤池对城市尾水净化效果研究

为明确以陶粒为填料生物滤池对尾水中主要营养物处理效果,选择球形陶粒滤池对城市尾水进行净化效果研究。试验在室温条件下采用水力停留时间约2 h,曝气量为0.4 L.min-1的陶粒曝气生物滤池装置对洛阳市某污水处理厂的尾水进行深度处理。研究结果表明：球形陶粒生物滤池对尾水中NH3-N去除效果良好,去除率达76%以上;同时该装置对TN,TP和COD具有同时去除作用。进一步研究陶粒对NH3-N吸附去除特征表明,其等温线吸附符合Freundlich Model,表明陶粒对NH3-N的吸附为多层吸附,且对NH3-N的吸附在5 h基本达到饱和吸附。     

PeLM: modeling of pesticide-losses through runoff and sediment transport

A GIS-aided pesticide loss model (PeLM) was developed to simulate pesticide losses through surface runoff and sediment transport in watershed systems. The PeLM could tackle the movement of eroded soil along with surface runoff as well as the pesticide losses in adsorbed and dissolved phases. The contributions of different soil types in the sediment were also examined. The model was applied to the Kintore Creek Watershed of southern Ontario, Canada. The simulation results were verified through observed data, indicating a correlation level of 0.89-0.98. The results also showed that clay particles usually held the largest share of contributions to pesticide losses through soil erosion. This study is significant in the efforts for modeling nonpoint source pollution in watershed systems. It provides useful information and support for the related decisions of watershed management.     

Particulate matter emissions from on-road vehicles in a freeway tunnel study

Particulate matter, including coarse particles (PM_2.5–10, aerodynamic diameter of particle between 2.5 and 10 μm) and fine particles (PM_2.5, aerodynamic diameter of particle lower than 2.5 μm) and their compositions, including elemental carbon, organic carbon, and 11 water-soluble ionic species, and elements, were measured in a tunnel study. A comparison of the six-hour average of light-duty vehicle (LDV) flow of the two sampling periods showed that the peak hours over the weekend were higher than those on weekdays. However, the flow of heavy-duty vehicles (HDVs) on the weekdays was significant higher than that during the weekend in this study. EC and OC content were 49% for PM_2.5–10 and 47% for PM_2.5 in the tunnel center. EC content was higher than OC content in PM_2.5–10, but EC was about 2.3 times OC for PM_2.5. Sulfate, nitrate, ammonium were the main species for PM_2.5–10 and PM_2.5. The element contents of Na, Al, Ca, Fe and K were over 0.8 μg m^?3 in PM_2.5–10 and PM_2.5. In addition, the concentrations of S, Ba, Pb, and Zn were higher than 0.1 μg m^?3 for PM_2.5–10 and PM_2.5. The emission factors of PM_2.5–10 and PM_2.5 were 18 ± 6.5 and 39 ± 11 mg km^?1-vehicle, respectively. The emission factors of EC/OC were 3.6/2.7 mg km^?1-vehicle for PM_2.5–10 and 15/4.7 mg km^?1-vehicle for PM_2.5 Furthermore, the emission factors of water-soluble ions were 0.028(Mg²⁺)–0.81(SO₄^2?) and 0.027(NO₂^?)–0.97(SO₄^2?) mg km^?1-vehicle for PM_2.5–10 and PM_2.5, respectively. Elemental emission factors were 0.003(V)–1.6(Fe) and 0.001(Cd)–1.05(Na) mg km^?1-vehicle for PM_2.5–10 and PM_2.5, respectively.     

用于地震预警系统的单台站防误触发算法研究

利用单台站的信息在较短的时间内识别地震事件和干扰事件是地震预警系统面临的关键问题。研究了基于波形特征参数的决策树方法来提高地震预警系统的单台抗干扰能力。为了研究电磁干扰对地震预警系统的影响,进行了7种电磁干扰试验。使用事件触发后3 s内的波形数据提取5个特征(事件结束否、Speed、Sparse、Pration、对称性),用决策树建立了特征值和事件类型之间的映射关系。使用了大量的强震记录和干扰记录(6359条强震记录、163条干扰记录)对训练后的决策树进行了验证。结果表明,所提方法识别率高,易转换成IF-THEN规则,能方便地写到计算机程序或专家系统中。该算法可以作为地震预警或报警系统的前端地震事件检测模块,以提高系统的可靠性。     

Effects of prenatal exposure to bisphenols on newborn leucocyte telomere length: a prospective birth cohort study in China

Environmental Science and Pollution Research - Telomere length (TL) at birth is related to diseases that may arise in the future and long-term health. Bisphenols exhibit toxic effects and can cross...     

Analytical methods for microplastics in the environment: a review

Environmental Chemistry Letters - Microplastic pollution is a recently discovered threat to ecosystems requiring the development of new analytical methods. Here, we review classical and advanced...     

Research status,challenges and future prospects of renewable synthetic fuel catalysts for CO2 photocatalytic reduction conversion

Environmental Science and Pollution Research - In recent years, with global climate change, the utilization of carbon dioxide as a resource has become an important goal of human society to achieve...     

地震作用下浮放物体的运动研究

本文从浮放物体的基本运动方程出发,导出了浮放物体受震振动的运动参数表达式,它是用仿真技术研究浮放物体地震运动的基本公式.     

低温等离子体催化氧化甲烷的实验研究

采用电容耦合等离子体和催化剂协同作用对干空气中的甲烷进行了氧化实验，并和没有放置催化剂时进行了对比，结果表明，放置催化剂后甲烷的分解效率明显提高，反应产物中CO2的选择性增加，副产物NO和NO2的浓度减少．反应所需的能耗降低。甲烷的最终氧化产物为CO、CO2和H2O。