Organochlorine pesticide in water and bottom sediment from Aiba Reservoir (Southwestern Nigeria)

Levels of organochlorine pesticides (OCPs) in water and sediment from Aiba reservoir (Southwestern Nigeria) have been assessed. The aim of the study was to investigate the pollution status of the reservoir water and the bottom sediment. Analytical measurements were carried out for 20 OCPs using standard literature methods. The results showed higher levels of OCPs in the bottom sediment than the water. Significant positive correlations at p<0.05 level were observed for OCPs compounds in water except γ-BHC and endosulfan III, whereas in sediments α-chlordane, dieldrin, endosulfan II, pp-DDT, endrin ketone and methoxychlor did not show any correlation, and aldrin was negatively correlated with pp-DDD. The mean levels of OCPs in both water and sediments were higher, in most cases, than recommended levels for drinking water. Owing to possible toxicity and bioaccumulation tendency of OCPs by the aquatic habitats, the levels of OCPs detected in water and sediment samples could be a source of future health problems. Environmental monitoring of the reservoir is highly recommended.     

热带气旋对海南岛臭氧污染的影响分析

基于2015～2020年西北太平洋生成的181个热带气旋资料,海南岛18个市县臭氧(O₃)小时浓度数据和气象观测资料,分析了热带气旋对海南岛O₃污染的影响.结果表明,近6年共有40个(22.1%)热带气旋的生命期间海南岛出现了O₃污染天气,热带气旋生成个数偏多的年份,O₃污染天数也偏多,其中2019年污染天数最多最严重,高污染(≥3个市县超标)天数高达39 d(54.9%).高污染(HP)类热带气旋有逐年增多趋势,趋势系数和气候倾向率分别为0.725(通过95%信度检验)和0.667个·a^-1.热带气旋强度与海南岛O₃最大8 h滑动浓度平均值(O₃-8h)成正相关关系,其中在台风(TY)等级,HP类热带气旋占所有样本数的比例高达35.4%.热带气旋路径聚类分析表明,南海生成影响型(A类)热带气旋生成个数最多,共有67个(37%),同时最容易造成海南岛出现大范围和高浓度的O₃污染,A类热带气旋中HP的个数和海南岛ρ...     

Human disturbance and shifts in vertebrate community composition in a biodiversity hotspot

Understanding how human modification of the landscape shapes vertebrate community composition is vital to understanding the current status and future trajectory of wildlife. Using a participatory approach, we deployed the largest camera-trap network in Mesoamerica to date to investigate how anthropogenic disturbance shapes the occupancy and co-occurrence of terrestrial vertebrate species in a tropical biodiversity hotspot: the Osa Peninsula, Costa Rica. We estimated species richness in different categories of land protection with rarefaction analysis and estimated the expected occupancy with a joint species distribution model that included covariates for anthropogenic disturbance, land protection, habitat quality, and habitat availability. Areas with the most stringent land-use protections (e.g., Corcovado National Park, 24 species [95% CI 23–25]) harbored significantly more species than unprotected areas (20 species [19.7–20.3]), mainly due to a reduced presence of large-bodied species of conservation concern in unprotected areas (e.g., jaguar Panthera onca and white-lipped peccary Tayassu pecari). Small-bodied generalist species, such as opossums (Didelphidae) and armadillos (Dasypus novemcinctus), in contrast, were more common at disturbed sites, resulting in a significant difference in vertebrate community composition between sites with low and high disturbance. Co-occurrence of species was also mainly associated with response to disturbance. Similar responses to disturbance create two groups of species, those whose site-level occupancy usually increased as anthropogenic disturbance increased and those whose estimated occupancy decreased. The absence of large-bodied species entails an important loss of ecological function in disturbed areas and can hinder forest development and maintenance. Efforts to protect and restore forested landscapes are likely having a positive effect on the abundance of some threatened species. These efforts, however, must be sustained and expanded to increase connectivity and ensure the long-term viability of the wildlife community.     

基于自然和模拟热带海洋大气环境中涂层性能变化的对比研究

目的 研究涂层在自然环境试验和实验室模拟环境试验下性能的变化情况，通过再现涂层在自然环境下的环境效应和损伤过程，进而验证该模拟热带海洋大气环境试验方法的合理性。方法 根据涂层在舰船、舰载机等装备上热带海洋大气实际服役环境的分析，通过对热带海洋大气环境温度、湿度、盐雾、太阳辐射环境因素的组合，综合设计模拟热带海洋大气环境试验方法的试验流程，开展3种涂层在海南万宁为期1 a和实验室总周期为7循环的对比试验。结果 3种涂层在自然环境试验和实验室模拟环境试验后，随着试验时间的延长，其性能变化趋势相似，失光率和色差增大，附着力明显降低，交流阻抗值减小。红外光谱分析显示，老化机理均未出现明显变化，以光泽和色差为基准的平均秩相关系数为0.87，为极强相关。结论 本模拟热带海洋大气环境试验方法设计合理，具有良好的模拟性。     

某产品大气腐蚀环境因素监测与环境数据应用模式研究

目的 对某产品服役环境中的主要腐蚀环境因素进行监测，并挖掘环境数据应用模式，为该产品服役环境的腐蚀条件分析提供数据支撑。方法 根据某产品寿命期环境剖面，对库房、舱室及户外环境中温度、相对湿度、盐雾等主要环境因素进行为期3 a的监测，并从多个方面探讨这3种环境因素的应用模式。结果 针对某产品开展了主要环境因素监测，得到了其在关键服役场所的腐蚀环境数据，监测数据成功应用于该型产品服役环境严酷度分析、实验室环境试验条件设计、维修保障措施拟定等方面。结论 开展某产品关键服役环境下的腐蚀环境因素监测，可支撑该型产品的“环境符合性评估”“大气腐蚀性严酷度评估”“环境控制要求制定”以及“环境试验方法研究”。得到的环境监测数据以及应用案例可供其他类似产品服役环境监测及数据应用提供参考。