微塑料和镉复合污染对狼尾草根际土壤微生物群落结构和功能的影响

微塑料和重金属复合污染对植物生长和根际微生物群落和功能的影响目前尚未清晰.以狼尾草为实验材料进行盆栽模拟试验,研究重金属镉（Cd）与不同种类MPs （PE、PS）、粒径（13 μm和550 μm）、质量分数（0.1%和1%）的微塑料复合污染对狼尾草生长、重金属积累和根际微生物群落功能的影响.结果表明,MPs和Cd复合污染条件下整体呈现对植物生长胁迫增加、Cd含量和积累量降低的趋势.MPs和Cd复合污染能改变细菌群落组成,降低细菌多样性,其中550 μm 0.1% PE+Cd处理组ACE指数和Chao1指数降低最显著.与单一Cd污染相比,不同MPs种类、质量分数和粒径的MPs添加能改变新陈代谢、氨基酸的转运和代谢、能量生成和转换等功能组的基因丰度,显著影响狼尾草根际土壤细菌的功能.研究采用宏基因组学的方法分析了MPs和Cd复合污染对狼尾草根际细菌群落和功能的影响,可为MPs重金属复合污染的生态毒理效应及其生物修复提供基础数据和科学依据.     

基于集对云的机坪运行管理移交安全评价研究*

为对航空器机坪运行管理移交下运行安全状况做出科学合理的评价,结合具体机场的机坪运行复杂性,首先引入PSR模型,从压力、状态和响应3个方面构建管理移交机场机坪运行安全评价指标体系;随后使用熵值法进行指标权重计算,并运用欧几里得度量函数进行组合赋权;接着引入集对理论和云模型,结合组合权重使用正向云发生器确定综合云联系度,利用Python绘制等级云图,评判系统安全等级;最后以某大型机场为例进行验证。研究结果表明:本文所提出的机坪运行管理移交安全评估评价方法经验证与实际运行情况相符,能够为机坪运行安全评价提供理论参考。     

基于高通量测序和代谢组学解析重金属污染对农田微生物群落组成和功能的影响

重金属污染会影响微生物组成和群落结构,其与微生物的相互关系一直是重金属污染生态学研究的热点.河南省新乡市是中国著名的电池生产城市,因电池生产废水污灌造成严重的土壤重金属污染.目前有关新乡市长期灌溉电池废水造成的重金属污染对微生物群落组成和代谢功能的影响鲜见报道.采集了新乡市某长期生产电池厂旁3个重金属污染位点,重金属含量测定表明Cd和Pb超过相关标准,分别超标34~66倍和1.5~2.32倍.采用高通量测序分析了细菌和真菌群落组成,结果表明细菌由芽孢杆菌属、节杆菌属、鞘氨醇单胞菌属和类诺卡氏菌属等优势属,真菌由油壶菌属、小不整球壳属、Gibellulopsis和被孢霉属等优势属组成,表明经过长期的重金属胁迫,新乡长期重金属污染土壤富含重金属抗性细菌和真菌.环境因子和微生物群落相关性分析表明,总量Cu、DTPA提取态Cu和水溶态Pb显著影响细菌群落组成,总量Cd、Ni、Pb、Zn、DTPA提取态Cu和水溶态Pb显著影响真菌群落组成.目前,关于重金属污染对微生物群落代谢影响的研究较少,采用非靶向代谢组学分析表明,不同位点间代谢产物具有差异.通路富集分析表明,这些差异代谢物涉及代谢过程、环境信息处理和翻译等遗传信息加工等,在微生物缓解重金属导致的胁迫和环境适应中可能起到作用.     

汉江上游不同林龄麻栎林枯落物的水文功能评价

麻栎林普遍存在于汉江上游,其涵养水源能力的发挥对维持汉江上游流域生态平衡具有重要的作用.于2020年12月对汉江上游天柱山3个不同林龄(15 a、25 a、33 a)的麻栎林样地进行了枯落物厚度和蓄积量调查,利用浸泡法测定了枯落物各水文功能指标,运用熵权法对3个林龄麻栎林枯落物的水源涵养能力进行了综合评价.结果表明:麻...     

基于GIS的生命线防震减灾系统

生命线系统的震害预测和震害分析是防震减灾研究的重要内容。本文利用地理信息系统（ＧＩＳ）强大的空间管理分析功能,建立了基于ＧＩＳ的生命线系统空间数据库,并根据生命线系统的特点,结合震害预测方法,在ＡｒｃＶｉｅｗ环境下集成了生命线防震减灾计算机系统。     

城市自然灾害的社会因素及防治对策研究

以社会、经济意义作标准,抑减自然灾害的重点应在城市、因而研究城市自然灾害的社会因素是当务之急.本文列出并分析了十大社会因素,它们是:1)城市地生态;2)城市的灾害文化背景;3)政策导向的正负效应;4)城市规划与建设;5)城市公共设施状况;6)人口和财富的集中程度;7)城市资源的开发利用;8)科技对城市减灾的贡献率;9)防灾减灾的误区;10)灾害应急.本文还认为以上十大因素对城市自然灾害的作用至少包括五个方面,它们是:1)诱发作用;2)放大作用;3)连接灾害链;4)承受灾害;5)抑减灾害.在以上基础上,本文提出了充分利用城市社会因素抗灾减灾的八条对策,即1)建立统一管理城市自然灾害工作的综合性政府机构势在必行;2)强化防灾减灾的背景工作;3)防灾减灾工作的立法;4)认清和摆正发展与灾害的关系;5)尊重科学、尊重知识,建立一套灾害顾问系统;6)建立一支快速救灾的专业队伍;7)加强保险事业与灾害研究和抑减工作的联系;8)城市间的协凋必须要有全局对策.     

Conversion Margins for the Major Uses of Agricultural Land and Their Variations in Shandong Province, China

It is of practical significance for the decision-making on country food security and farmland protection to analyze the conversion margins for the major uses of agricultural land and their variations. Based on the panel data of wheat, corn, vegetable, fruit, and forests productions from 520 investigated farmer households of 13 investigated villages in Shandong Province from 2003 to 2009, and using Cobb-Douglas production function, the revenue conversion margins can be obtained separately, between different grain-crops (wheat, corn) and different non-grain crops (vegetable, fruit, forests), and the conversion relationship between growing grain( wheat, corn) and going out for non-farm work. The results show that from 2003 to 2009, growing wheat and corn are more economically and reasonably for farmers, compared with growing vegetable, but growing wheat and corn are becoming less economically and less reasonably day by day, compared with planting forests. Moreover, the conversion margin between wheat and fruit shows obvious scissors difference. Just from 2007, farmers’ growing fruit became economically and reasonably, but until 2009, compared with going out to work after abandoning farm8land, growing wheat had no economic rationality. From 2003 to 2009, farmers’ growing corn is more profitable than growing fruit and going out for non-farm work after abandoning farmland. The subsidies for wheat and corn have increased farmers’ comparative income from food production remarkably, but the subsidies cannot change the general tendency that farmers transform food (wheat, corn) production into non-food (especially forests) production. The revenue difference between growing wheat, corn and vegetable and growing fruit and forests is being pulled ceaselessly bigger, and the tendency that farmers transform wheat, corn and vegetable growing lands into fruit and forests growing lands has become increasingly apparent.     

基于复合污染指数的省级环境技术效率测算

在环境问题,特别是当前复合污染问题愈加突出的背景下,运用科学方法对复合污染程度进行量化测度,并在此基础上分析各个省份的环境技术效率,可以为制定相关政策、开展节能减排工作提供重要依据.该文尝试用熵值法及污染物权重系数调整构建复合污染指数,并在此基础上,利用方向性距离函数,对我国29个省区市2003 - 2009年间复合污染状况、区域环境技术效率进行了系统分析.研究结果表明:我国各省的环境技术效率有较大的差异,东部省份最高,中部次之,西部最为落后.绝大多数省份的环境技术效率值随时间变化呈下降趋势,但是下降的幅度不是很大,这种变化很大程度上可能源于我国“十一五”中后期经济发展模式的逆转,钢铁、水泥、电解铝、煤炭等行业发展过快,2005年重工业占工业总产值的比重高达69％,显现出过度工业化的特征.直观分析可以看出,环境技术效率的变动与环境污染程度之间存在反向关系,环境技术效率的水平对环境污染程度大小的影响较大.     

A Technicoeconomic Approach for theSelection of a Site Remediation Strategy—Part B: Model Application

Different tools, such as a screening matrix or decision framework, are available to select a remediation technology to treat a contaminated site. However, unless these methods can point out the appropriate technology in regards to the decision-maker's knowledge about the contaminated site, they are less useful to evaluate both the technical effectiveness and the cost of the remediation, and to assess different remediation strategies from either future data acquisition or the use of an irreversible remediation technology. A model developed to allow such evaluations has been used to simulate the remediation of a virtual contaminated site. From this, four remediation recommendations have been made. These recommendations are guidelines for the build up of a remediation strategy that would both maximize the effectiveness of the decontamination and minimize its total cost.     

Measuring eddy covariance fluxes of ozone with a slow-response analyser

Ozone (O₃) fluxes above a temperate mountain grassland were measured by means of the eddy covariance (EC) method using a slow-response O₃ analyser. The resultant flux loss was corrected for by a series of transfer functions which model the various sources of high- and, in particular, low-pass filtering. The resulting correction factors varied on average between 1.7 and 3.5 during night and daytime, respectively. A cospectral analysis confirmed the accuracy of this approach. O₃ fluxes were characterised by a comparatively large random uncertainty, which during daytime typically amounted to 60%. EC O₃ fluxes were compared against O₃ flux measurements made concurrently with the flux-gradient (FG) method. The two methods generally agreed well, except for a period between sunrise and early afternoon, when the FG method was suspected of being affected by the presence of photochemical sources/sinks. O₃ flux magnitudes and deposition velocities determined with the EC method compared nicely with the available literature from grassland studies. We conclude that our understanding of the causes and consequences of various sources of flux loss (associated with any EC system) has sufficiently matured so that also less-than-ideal instrumentation may be used in EC flux applications, albeit at the cost of relatively large empirical corrections.