Effects of Topographical Heterogeneity and Dispersal Limitation on Species Turnover in a Temperate Mountane Ecosystem: a Case Study in the Henan Province,China

Species turnover patterns can be inconsistent due to differences in the dispersal ability of different growth forms. Here, species of trees, shrubs, herbs, and bryophytes in the Xiaoqinling National Nature Reserve in China were analyzed to determine patterns of species turnover along an elevation and spatial gradient. Variance partitioning was used to assess the relative contribution of topographic heterogeneity and dispersal limitation to species turnover. Our results suggest that the effect of dispersal limitation is more important than topographic heterogeneity on species turnover in temperate mountane ecosystems in the study area. Dispersal limitation has a greater effect on trees species turnover than on shrubs, herbs or bryophytes species turnover.     

基于微型无人机遥感数据的城市水环境信息提取初探

近年来,黑臭水体整治已经成为各级政府的重要工作内容。为更好地开展黑臭水体筛查和监管工作,提出基于多旋翼无人机搭载多光谱相机的遥感监测方案,尝试采用影像特征变换结合面向对象分类方法提取黑臭水体的遥感信息。结果表明:(1)无人机影像上地物具有更加丰富的色彩和纹理;(2)与主成分变换和纹理分析方法相比,光谱指数对典型地物具有较好的判别能力;(3)采用标准最邻近分类法提取城市水环境信息,能够获得较高分类精度。     

以红薯浸泡液为碳源的生物反硝化

为选择低碳氮比污水生物脱氮中合适的碳源,以搅拌罐浸泡淀粉类物质释放碳源,在确定利用红薯浸泡液为碳源后,以浸没式生物滤池为反应器进行生物反硝化实验。实验结果表明:20 g红薯置于2 L自来水中,采用250 r/m in的搅拌速度,搅拌频率为每搅拌3 h停1 h,2 d后得到的浸泡液COD浓度平均为5 921 mg/L,最高可超过7 000 mg/L;将此红薯浸泡液和污水以1∶50的流量比例,采用分别投加的方式进入反应器,污水中总氮、硝酸盐氮、亚硝酸盐氮及氨氮的平均去除率分别为88.6%、91.6%、88.2%和54.8%,出水COD平均在30 mg/L以下;在红薯浸泡液COD浓度为5 700 mg/L左右时,进水中亚硝酸盐氮浓度与硝酸盐氮浓度比为3∶2时总氮去除率为95.3%,当该比例为2∶3时总氮去除率为88.2%。研究表明,红薯浸泡液是一种经济合适的碳源,采用红薯浸泡液作为低碳氮比污水生物处理中反硝化的碳源是可行的。     

麻质活性炭的制备及其对Cu~(2+)的吸附研究

以废麻为原料,KOH为活化剂制备粉状活性炭,通过静态吸附实验研究了活性炭对Cu2+的吸附性能,探讨了溶液起始pH值、活性炭投加量、吸附时间、起始Cu2+质量浓度等对Cu2+吸附效果的影响。结果表明,溶液pH和活性炭投加量对吸附效果有较大影响,活性炭对Cu2+的吸附率在60 min内超过50%,初始浓度在10~50 mg/L时,活性炭对Cu2+的吸附量与起始浓度近似成正比。采用Langmuir、Freundlich吸附等温式对吸附平衡数据进行了拟合,结果表明吸附等温线符合Frenudlich模型。采用傅立叶红外光谱法(FT-IR)分析了活性炭的表面官能团,分析表明活性炭表面酸性官能团可能是吸附Cu2+的活性中心。     

Impact of anthropogenic emissions and open biomass burning on regional carbonaceous aerosols in South China

Carbonaceous aerosols were studied at three background sites in south and southwest China. Hok Tsui in Hong Kong had the highest concentrations of carbonaceous aerosols (OC = 8.7 ± 4.5 μg/m³, EC = 2.5 ± 1.9 μg/m³) among the three sites, and Jianfeng Mountains in Hainan Island (OC = 5.8 ± 2.6 μg/m³, EC = 0.8 ± 0.4 μg/m³) and Tengchong mountain over the east edge of the Tibetan Plateau (OC = 4.8 ± 4.0 μg/m³, EC = 0.5 ± 0.4 μg/m³) showed similar concentration levels. Distinct seasonal patterns with higher concentrations during the winter, and lower concentrations during the summertime were observed, which may be caused by the changes of the regional emissions, and monsoon effects. The industrial and vehicular emissions in East, Southeast and South China, and the regional open biomass burning in the Indo-Myanmar region of Asia were probably the two major potential sources for carbonaceous matters in this region.     

污泥热解残渣制备聚合氯化铝的实验研究＊

含铝污泥热解或焚烧残渣制备聚合氯化铝的研究,有利于实现污水处理过程投加的铝盐絮凝药剂的回收与高效循环利用,减少污染物排放和资源消耗。针对辽河油田欢三联稠油污水处理污泥的热解残渣具有较高铝含量的特点,开展采用盐酸进行铝溶出及制备聚合氯化铝的实验研究。结果表明:焙烧温度为700～750℃,焙烧时间控制在1h即可。将经过焙烧活化的残渣在常温下进行酸溶,酸溶时间为2～5h,选用25%～30%盐酸,氧化铝与盐酸的摩尔比为1∶1.0～1∶1.2为宜。将溶出的铝溶液制备聚合氯化铝,在常温下采用CaO粉末来调节pH值为3.5,聚合反应时间为1d,即可得聚合氯化铝溶液。     

嗜盐菌在油田含盐采出废水处理中的应用

嗜盐菌具有独特的细胞结构、生理功能和代谢产物,能够在高盐环境下正常生存和生长,适宜于偏碱性的环境,因而能有效应用于含盐污染物的治理。结合油田含盐采出废水的特点,介绍了嗜盐菌的特点、嗜盐机制等,及嗜盐菌在含盐采出废水和其它有机污染物处理中的作用,为油田含盐采出废水的处理提供理论基础和技术依据,并为更大范围地推广嗜盐菌在油田含盐采出废水处理中的应用提供技术参考。     

Evaluation of airborne particulate matter and metals data in personal,indoor and outdoor environments using ED-XRF and ICP-MS and co-located duplicate samples

Factors and sources affecting measurement uncertainty associated with monitoring metals in airborne particulate matter (PM) were investigated as part of the Windsor, Ontario Exposure Assessment Study (WOEAS). The assessment was made using co-located duplicate samples and a comparison of two analytical approaches: ED-XRF and ICP-MS. Sampling variability was estimated using relative percent difference (RPD) of co-located duplicate samples. The comparison of ICP-MS and ED-XRF results yields very good correlations (R² ≥ 0.7) for elements present at concentrations that pass both ICP-MS and ED-XRF detection limits (e.g. Fe, Mn, Zn, Pb and Cu). PM concentration ranges (median, sample number) of 24-h indoor PM₁₀ and personal PM₁₀ filters, and outdoor PM_2.5 filters were determined to be 2.2–40.7 (11.0, n = 48) μg m^?3, 8.0–48.3 (11.9, n = 48) μg m^?3, and 17.1–42.3 (21.6, n = 18) μg m^?3, respectively. The gravimetric analytical results reveal that the variations in PM mass measurements for same-day sampling are insignificant compared to temporal or spatial variations: 92%, 100% and 96% of indoor, outdoor and personal duplicate samples, respectively, pass the quality criteria (RPD ≤ 20%). Uncertainties associated with ED-XRF elemental measurements of S, Ca, Mn, Fe and Zn for 24-h filter samples are low: 78%–100% of the duplicate samples passed the quality criteria. In the case of 24-h filter samples using ICP-MS, more elements passed the quality criteria due to the lower detection limits. These were: Li, Na, K, Ca, Si, Al, V, Fe, Mn, Co, Cu, Mo, Ag, Zn, Pb, As, Mg, Sb, Sn, Sr, Th, Ti, Tl, and U. Low air concentrations of metals (near or below instrumental detection limits) and/or inadvertent introduction of metal contamination are the main causes for excluding elements based on the pass/fail criteria. Uncertainty associated with elemental measurements must be assessed on an element-by-element basis.     

接地极的土壤腐蚀

接地极是接地装置的主要组成部分,接地极埋设在土壤中,用于泄流,保障电网和电气设备的安全运行。近年来,接地极的腐蚀损坏造成的事故屡有发生,接地极的土壤腐蚀引起了普遍的重视,防止接地极腐蚀已成为一个重要的研究课题。本文介绍了目前我国电网和电气设备接地极的选材,接地极土壤腐蚀的特点,并对接地极防腐蚀方法做了简单总结。     

Effects of di-n-butyl phthalate on the physiology and ultrastructure of cucumber seedling roots

Agricultural pollution caused by the use of plastic sheetings has been documented to be a widespread problem in most of the major crop-planting regions of the world. In order to better understand the phytotoxic mechanisms induced by phthalic acid esters involved with this problem, Cucumber sativus L. cv Jinyan No. 4 were sown in pots to the three-leaf-stage in the presence of di-n-butyl phthalate (DBP; 0, 30, 50, 100, and 200 mg L^?1) for 1, 3, 5, or 7 days. Physiology, biochemistry, and ultrastructure of seedling roots were examined. The results indicated that activities of three antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD)) were stimulated at low-DBP treatments and decreased under higher levels (>100 mg L^?1) compared to the controls. On the other hand, SOD and POD provided a better defense against DBP-induced oxidative damage in the roots of cucumber seeding, compared to CAT. The productions of both malondialdehyde (MDA) and proline (Pro) were promoted under DBP stress. Visible impact on the cytoderm, mitochondrion, and vacuole was detected, possibly as a consequence of free radical generation. These results suggested that activation of the antioxidant system by DBP led to the formation of reactive oxygen species that resulted in cellular damage.