Using cumulative human-impact models to reveal global threat patterns for seahorses

Understanding threats acting on marine organisms and their conservation status is vital but challenging given a paucity of data. We studied the cumulative human impact (CHI) on and conservation status of seahorses (Hippocampus spp.)—a genus of rare and data-poor marine fishes. With expert knowledge and relevant spatial data sets, we built linear-additive models to assess and map the CHI of 12 anthropogenic stressors on 42 seahorse species. We examined the utility of indices of estimated impact (impact of each stressor and CHI) in predicting conservation status for species with random forest (RF) models. The CHI values for threatened species were significantly higher than those for nonthreatened species (category based on International Union for Conservation of Nature Red List). We derived high-accuracy RF models (87% and 96%) that predicted that 5 of the 17 data-deficient species were threatened. Demersal fishing practices with high bycatch and pollution were the best predictors of threat category. Major threat epicenters were in China, Southeast Asia, and Europe. Our results and maps of CHI may help guide global seahorse conservation and indicate that modeling and mapping human impacts can reveal threat patterns and conservation status for data-poor species. We found that for exploring threat patterns of focal species, species-level CHI models are better than existing ecosystem-level CHI models.     

Policy-making coordination of municipal solid waste policies in China: a content analysis

Journal of Material Cycles and Waste Management - Massive urbanization and rapid development of urban economy have increased the generation of municipal solid waste in China. Like all developing...     

适应钝感弹药发展提高武器系统使用的安全性

为了适应钝感弹药发展的需求,利用冲击波汇聚技术和起爆理论,研究了环形、锥环形两种新型传爆药装药结构。试验表明,环形传爆药较圆柱形传爆药可减少药量约１５％ ,锥环形传爆药较圆柱形传爆药可减少药量约２６％ 。研究结果对于减少武器爆炸序列中敏感元件——传爆药的使用数量,进而提高武器系统使用安全性具有重要意义     

硝酸铵气溶胶挥发动力学

研究了单分散ＮＨ４ＮＯ３干气溶胶在流动反应器内的挥发动力学,结果表明,挥发反应符合零级反应,凝聚反应符合二级反应,ＮＨ４ＮＯ３气溶胶计算粒径为０．６５μｍ,计算数浓度为８０－１２０个／ｃｍ＾３时,     

不同来源的海州香薷和野胡萝卜的铜抗性及铜积累差异

以来自矿区(铜绿山和赤马山铜矿)和非矿区(红安、武汉严西湖)的海州香薷和野胡萝卜种群为对象,通过土培实验,研究了2种植物的铜抗性及铜吸收积累差异.结果显示,来自矿区的海州香薷和野胡萝卜种群的铜抗性都明显高于非矿区种群,但2种植物种群的铜吸收积累特征明显不同:海州香薷植物吸收的Cu主要集中在根中,但矿区种群吸收积累的铜量明显低于非矿区种群;而野胡萝卜吸收的Cu主要集中在地上部分(地上部分的Cu富集量是根的1.5倍),但积累的铜量在矿区和非矿区种群间没有明显的差异.因此,来自矿区的海州香薷可能进化为铜避性对策,而野胡萝卜的铜抗性与其吸收积累的总量没有明显的关系,但有很好的向地上运输能力.     

微生物絮凝剂EBU-1的化学性质分析

对一株产碱假单胞菌(Pseudomonas alcaligenes)产生的微生物絮凝剂EBU1的化学性质进行初步研究,结果显示,EBU-1具有良好的热稳定性;呈色反应为多糖的颜色反应,没有蛋白质的颜色反应;紫外和红外扫描确定EBU-1含多糖及少量核酸,含量分别为82.3%和8.6%;电负性实验表明,EBU-1是阴离子型微生物絮凝剂。     

纳米材料的水生态毒理学研究进展

纳米材料特殊的理化特性,使它们被广泛地应用到各个生活领域中,但纳米材料给人们生活带来巨大改变的同时,其对水环境引起的负面效应也引起了人们广泛的关注.纳米材料可通过多种途径进入水体,对水生生物产生毒理效应,其生态学影响不可忽视.目前,还很缺乏对纳米材料的水生态毒理学研究,众多不确定的生态安全性问题还有待更深入的研究.总结了国内外现有的相关研究,简要综述了纳米材料的水环境行为、水生态毒理学研究现状,分析了该研究领域的未来需要.     

The degradation of chlorpyrifos and diazinon in aqueous solution by ultrasonic irradiation: effect of parameters and degradation pathway

In this paper, elimination of two types of organophosphorus pesticides (OPPs), chlorpyrifos and diazinon spiked in aqueous solution by ultrasonic irradiation was investigated. Results showed that chlorpyrifos and diazinon could be effectively and rapidly degraded by ultrasonic irradiation, and the degradation of both pesticides was strongly influenced by ultrasonic power, temperature and pH value. Furthermore, two and seven products for the degradation of chlorpyrifos and diazinon formed during ultrasonic irradiation have been identified by gas chromatography-mass spectrometry, respectively. The hydrolysis, oxidation, hydroxylation, dehydration and decarboxylation were deduced to contribute to the degradation reaction and the degradation pathway for each pesticide under ultrasonic irradiation was proposed. Finally, the toxicity evaluation indicated that the toxicity decreased for diazinon solution after ultrasonic irradiation, but it increased for chlorpyrifos solution. The detoxification of OPPs by ultrasonic irradiation was discriminative.     

Concentrations, spatial distributions and congener profiles of polychlorinated biphenyls in soils from a coastal city--Tianjin, China

A total of 82 surface soil samples collected from central urban sites, surrounding rural sites, coastal sites and background sites in Tianjin were analyzed for 84 PCB congeners. The mean values of total PCBs concentrations for surrounding rural sites, central urban sites, coastal sites, background sites and the whole Tianjin region were 4.45, 3.20, 12.65, 1.96 and 4.02 ng g(-1), respectively. No "urban fractionation effect" was found in Tianjin, which reflected the influence of local emission sources for PCBs such as industries and township enterprises in surrounding rural sites. In contrast, a "primary fractionation effect" was found in Tianjin region. The PCBs concentrations for whole Tianjin region showed a strong east-west gradient and the percentages of lighter molecular weight PCBs homologs (sum of di- to tetra-PCBs) to the total PCBs concentrations increased from east to west. The seven indicator PCBs concentrations were well correlated with the total PCBs concentrations with the correlation coefficients as 0.76 for Tianjin region and 0.74 for central urban sites, respectively. Predominant PCB homolog groups were penta- and tri-PCBs for Tianjin region. 10 dioxin-like PCBs concentrations were well correlated with total PCBs concentrations for all the sampling sites (R=0.79, P<0.0001). The TEQ concentrations for 10 dioxin-like PCBs were 5.3424 ng kg(-1) for Tianjin region and showed a strong east to west gradient. The spatial distribution of PCBs levels, homolog composition patterns and TEQ concentrations were all obviously influenced by local emission sources for PCBs in the east part of Tianjin region.     

北京市雷电灾害灾情综合评估模式

在灾情网络分析的基础上,建立了北京市雷电灾害的灾情评估指标体系。通过对体系内的各评估指标进行量化分析,给出灾情评估指标的量纲换算表,进而确定了北京市雷电灾害的灾情综合评估模式,并对评估结果进行了等级划分。通过实例评估发现,此综合评估模式简单易于操作,且评估结果能较好地反映北京市雷电灾害的综合损失。