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.     

横截面形状对旋风分离器性能影响的数值模拟

采用CFD商业计算软件FLUENT对横截面形状影响旋风分离器性能的情况进行了数值模拟。模拟中,气相采用雷诺应力湍流模型RSM封闭N-S方程,固相采用基于Euler-Lagrange方法的离散相模型DPM。通过对旋风分离器圆形、八边形、七边形、六边形、五边形、四边形横截面形状的比较,模拟并分析了分离器两个主要性能分离效率和压力损失的变化规律,提出了横截面为八边形的分离器的相对优势,可用于传统旋风分离器结构型式的设计和优化。     

Traditional warning signs of cyclones on remote islands in Fiji and Tonga

Traditional knowledge of disasters has been found to save lives. On remote islands where telecommunications to the mainland are unreliable, unless there are always working batteries in the radio, signs from the environment may be the only warning of an oncoming cyclone. But this knowledge is in danger of being lost, as it is an oral history not well documented, and younger people increasingly rely on technology. This article presents the results of fieldwork on remote islands in Fiji and Tonga in the South Pacific, documenting natural warning signs on islands in two different countries. The results show that there are numerous known signs, with remarkable similarities and consistencies between the two islands. This provides evidence that not only is traditional knowledge of warning signs for cyclones alive and well, the consistency in the signs suggests support for this knowledge as being just as important as western scientific knowledge. The integration of traditional knowledge and western scientific knowledge into a comprehensive warning system may help to overcome some of the limitations of the existing system and the reasons why warnings are sometimes ignored.     

石化废水生化处理工艺优化及提标改造

针对已建炼化污水处理装置提质达标的需求,采用旋流强化工艺对缺氧-好氧（A/O）池进行改造,生化出水TN由（32.8±8.9）mg/L降至（25.6±5.7） mg/L,TN平均去除率提高了约10百分点,且出水TN达标率达到100%,出水水质稳定达到GB 31570—2015《石油炼制行业污染物排放标准》的TN排放限值要求。旋流强化工艺技术先进,便于实施,适用于石化行业污水处理装置的改造升级,具有广泛的应用前景。     

用固-液旋流工艺处理油田集输泵站含油泥砂

采用固-液旋流工艺处理集输泵站含油泥砂。研究了旋流处理工艺流程及操作参数、悬浮液性质对处理效果的影响,确定了最佳工艺条件。当温度为43℃、溢流流量为12．6m,／h、泵压为0．295MPa、进料中油质量分数大于17％时,油去除率可达到98％,油质量分数控制在0．45％以内,达到排放标准。实验表明,二次旋流的效果优于一次旋流效果。该工艺同时回收了含油泥砂中的油,利于油田泵站清洁生产。     

Effects of Forest Fragmentation and Habitat Degradation on West African Leaf-Litter Frogs

Abstract:  Habitat degradation alters the dynamics and composition of anuran assemblages in tropical forests. The effects of forest fragmentation on the composition of anuran assemblages are so far poorly known. We studied the joint influence of forest fragmentation and degradation on leaf-litter frogs. We specifically asked whether the processes structuring leaf-litter anuran assemblages in fragmented forests are the same as those in continuous forests. We analyzed anuran assemblages with respect to habitat characteristics, including fragmentation and degradation parameters. In comparison with continuous forests, species richness and diversity were lower and assemblage composition was altered in forest fragments. These changes seemed to be mainly caused by habitat degradation rather than forest fragmentation. Availability of aquatic sites for breeding, vegetation structure (including those variables indicating degradation), and leaf-litter cover had the most influence on the presence of single species. The comparatively small impact of fragmentation on anurans might be due to the location of the study area; it still possessed large tracts of continuous forest. These forest blocks may stabilize the regional rainforest climate and thus weaken the effects of fragmentation .     

热带岛礁大气环境车辆装备腐蚀规律与防护设计及控制措施

目的 提高车辆装备在热带岛礁大气环境中的耐腐蚀性能,为车辆装备在热带岛礁大气环境长期稳定的服役提供防腐蚀设计与改进依据。方法 通过对岛礁大气环境特点的分析和典型车辆装备腐蚀规律研究与总结,制定相应的腐蚀防护设计及措施,并在车辆装备上进行应用与验证。结果 根据腐蚀特点,车辆装备划分为结构类腐蚀、电气类产品腐蚀、材料和涂层腐蚀等4类,其中,结构类腐蚀是最主要的腐蚀行为,结构类腐蚀类型主要包括缝隙腐蚀、电偶腐蚀、应力作用下腐蚀、磨损腐蚀、结构外形及空腔结构造成的腐蚀等。根据腐蚀环境进行划分,将整车划分为舱外完全暴露结构区域、底盘底部区域、发动机舱区域和舱内区域等4个腐蚀区域。在车辆装备上采取相应的腐蚀防护设计与措施,包括典型结构类防腐蚀设计、电气类产品腐蚀防护设计、材料与涂层搭配选用、维护保养和腐蚀监测措施,在热带岛礁大气环境中取得了良好的应用验证效果。结论 根据不同腐蚀类型,采取相应的结构类、电气类产品,材料与涂层合理搭配选用等腐蚀防护设计,加严环境试验考核,以及维修维护、腐蚀监测等腐蚀控制措施,车辆装备在热带岛礁环境中将取得长效且良好的环境适应性。     

3个深入内陆热带气旋产生大暴雨的成因——对比分析

利用常规气象观测资料、NCEP等资料,对2006年3个深入内陆的热带气旋产生大暴雨的水汽、动力和热力条件进行了对比分析。结果表明:(1)碧利斯虽强度属3个热带气旋中最弱的一个(只达强热带风暴等级),但由于它与南侧强西南季风结合,使其产生暴雨的水汽、动力和热力条件异常强盛,因而导致其暴雨强度最强、范围最大、灾害最严重;(2)螺旋度垂直分量20×10-7hPa.s-2等值线包围区的水平范围和螺旋度正值区垂直伸展高度及各层中心值强度与暴雨强弱有较好的关系,且暴雨区主要落在700 hPa 20×10-7hPa.s-2等值线包围区内;(3)暴雨发生时,3个热带气旋的湿位涡MPV1场均呈现下负上正分布,说明低层为不稳定层,同时均出现高层MPV1正值区向低层下伸的现象,反映不稳定能量开始释放;(4)由于3个热带气旋均未与冷空气结合,故MPV2值均较小,因此湿位涡的湿正压项(MPV1)对产生暴雨的作用大于湿斜压项(MPV2)。     

7050铝合金硬质阳极氧化膜热带海洋大气环境耐蚀性能研究

目的 研究7050铝合金硬质阳极氧化膜在热带海洋大气环境下的耐蚀性能变化规律。方法 在7050铝合金表面制备硬质阳极氧化膜,然后采用不封闭、沸水封闭与铬酸盐封闭3种后处理方式进行处理。采用实验室多因素组合循环模拟试验方式与热带海洋大气环境户外直接暴露对试样开展耐蚀性能试验。通过外观、极化曲线、电化学阻抗谱方法,分析其耐蚀性能变化规律。结果 硬质阳极氧化膜不封闭处理的耐蚀性较差,实验室多因素组合循环试验第1循环后表面就出现白色腐蚀产物,评级为5/2xA。户外暴露试验12个月后,不封闭处理膜层的自腐蚀电位为?814.88 mV,自腐蚀电流密度为0.307µA/cm²;沸水封闭膜层的自腐蚀电位为?717.86 mV,自腐蚀电流密度为0.177 µA/cm²;重铬酸盐封闭膜层的自腐蚀电位为?703.33 mV,自腐蚀电流密度为3.82×10^?2 µA/cm²。户外暴露12个月后,不封闭处理、沸水封闭处理与重铬酸盐封闭处理膜层在0.01 Hz的阻抗模值分别为1.04×10⁵、1.51×10⁵、4.76×10⁵ Ω.cm²。结论 封闭处理能提升7050铝合金硬质阳极氧化膜的耐蚀性能,且重铬酸盐封闭后的耐蚀性能优于沸水封闭后的耐蚀性能。     

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...