无机复配防霉剂对木竹材性能的影响

为获得低成本、低毒环保、工艺简便且高性能的木竹材防霉剂,采用无机试剂硫酸铜、硼酸及双氧水复配防霉剂,对杨木和毛竹材进行浸渍处理,并考察其防霉功效,同时探究试剂对木竹材物理力学性能的影响,结果表明:浓度为1%硫酸铜、1.5%硼酸与6%双氧水复配的无机试剂抑菌效果较好,且对杨木及毛竹17 d的防治效力达到100%;复配防霉剂对试材的物理力学性能影响不大,但会导致试材表面色差增加。研究结论为低毒无机木竹材防霉剂的开发和应用提供基础理论依据。     

Concentrations,sources, and influential factors of water- soluble ions of atmospheric particles in Dunhuang Mogao Grottoes,a world heritage site in China

Atmospheric particle pollution is one of the major factors leading to degradation of ancient wall paintings, particularly heritage sites in arid and semi-arid regions. However, current systematic research on the changes, sources, and influential factors of atmospheric particulate matter and its water-soluble ion concentrations is not sufficient. Thus, the major water-soluble ion concentrations, sources, and influential factors of atmospheric particles PM_2.5 and PM₁₀ (particulate matter with an aerodynamic equivalent diameter ≤2.5 and 10.0 μm, respectively, in ambient air) were collected from Cave 16 and its ambient exterior environment in the Dunhuang Mogao Grottoes, China, between April 2015 and March 2016. Results showed that the concentrations of PM_2.5 and PM₁₀ inside and outside the cave were the highest in March 2016 and the lowest in December 2015. The higher particle concentration from March to May was related to the frequent occurrence of sand and dust events, and the lower particle concentration from June to September was associated with good diffusion conditions, increased precipitation, and an established cave shelterbelt. The concentration of particulate matter inside the cave was affected by the concentration of particles in the air outside the cave. Ca²⁺, NH+ 4, Na⁺, Cl^-, and SO2- 4were the main components of the total ions of PM_2.5 and PM₁₀ both inside and outside the cave. The total ions inside the cave were frequently affected by the disturbance of tourists' activities during the peak tourist season from May to August. Under the influence of dust, the total concentrations of Cl^-, SO2- 4, Na⁺, NH+ 4, and Ca²⁺ in particles of different sizes inside and outside the cave increased, and the concentrations of Cl^-, SO2- 4, Na⁺, and Ca²⁺ decreased during precipitation period. Backward air mass trajectory analysis suggested that the pollutants were mainly from Xinjiang, China. The pollutant sources of air particulates are straw burning, secondary pollution sources, soil dust, dry spring rivers, and tourist activities.     

株洲市菜区美洲斑潜蝇发生规律及其防治试验

美洲斑潜蝇对作物的危害较大，为摸清其生长发育规律、危害状况及防治方法，采取了定田定点的方法进行调查，针对其消长规律进行了不同药剂防治试验，结果表明，生物农药爱福丁防治效果较好