干旱、半干旱地区公路绿化中抗旱技术

在干旱、半干旱地区公路绿化中水是最主要制约因素，通过合理设计、选择适宜植物生长的时期种植和采用高分子化合物等，从而达到抗旱和防治水毁的目的。     

土壤中苯并[α]芘的准确度控制指标研究

通过全国多家实验室的大量监测数据,研究分析了土壤中苯并[α]芘测定的准确度控制指标,并与EPA8270D进行了比较,旨在为环境监测工作提供质量控制依据和指标。研究表明,标准样品测定的相对误差控制范围0～56.4%,实际样品加标回收率为55.8%～115%。     

离子液体[C8mim]PF6对水生生物的毒性作用

运用评价化学品对水生生物毒性的标准试验方法,探讨离子液体1-辛基-3-甲基-咪唑六氟磷酸盐([C8mim]PF6)对普通小球藻、大型蚤和斑马鱼的毒性影响.结果表明,[C8mim]PF6在实验浓度下,对普通小球藻的生长和叶绿素a的产生均有抑制作用,浓度越高抑制作用越明显,且对叶绿素a含量的影响更为显著.高浓度组(200mg/L)可致死部分小球藻细胞;[C8mim]PF6对大型蚤的48h LC50为4.47mg/L,属于高毒性;[C8mim]PF6对斑马鱼的96h LC50为126.08mg/L,属于低毒性.[C8mim]PF6对这3种水生生物的抑制率/致死率(EC50/LC50)随时间呈规律性变化.[C8mim]PF6与藻类的亲和性及其亲脂特性可能是其对水生生物存在潜在毒性的2个主要原因.     

The synergistic interaction of Nickel(II) with dna damaging agents

In this report we present several examples in which nickel(II) in combination with DNA damaging agents caused an enhanced or synergistic biological response using several different endpoints. These examples of Ni(II) toxicity represent several approaches designed to understand the genotoxicity of Ni(II) as well as several other metal ions. They are discussed in this report as a partial basis for our hypothesis that Ni(II) may alter the cellular processing of DNA damage at some common point in the pathway for DNA repair of several different agents. In cultured Chinese hamster cells DNA damage by Ni(II) ions was not readily demonstrated by the method of alkaline elution, but pretreatment of cells with Ni(II) before X‐irradiation produced an enhanced amount of strand breaks compared to the amount produced by X‐rays alone. A synergistic enhancement of cell transformation of Syrian hamster embryo cells was observed for combined treatments of Ni(II) and benzo(a)pyrene. The nickel enhancement of mutagenesis by ultraviolet light was demonstrated for the bacterial gene gpt stably integrated into the Chinese hamster V79 genome.     

如何推动地方落实13万个建制村的环境综合整治任务

随着我国财税体制改革步伐的不断加快,农村环境"以奖促治"政策的实施范围、推进方式、资金管理等发生了深刻变化,同时,一些地方农村环境综合整治又存在政府积极性不高、责任难以落实、环境成效较差的问题,如何推动地方落实《水污染防治行动计划》提出的,到2020年完成13万个建制村的环境综合整治任务,是现阶段我国农村环境综合整治面临的新形势。本文在准确把握当前农村环境综合整治形势下,提出了今后一个时期推进我国农村环境综合整治的工作思路,分别从严格目标考核、引入激励机制、建立长效机制和重视各方参与4个方面,提出了约束与激励相结合的农村环境保护措施,以期为新时期深化"以奖促治"政策、推进农村环境综合整治提供参考和借鉴。     

关于发展生物质产业的几点思考

我国生物质产业自20世纪70年代开始起步。乙醇汽油和沼气利用是生物质能开发中的重点。虽然生物质产业的关键技术基本成熟。但是当考虑不再用粮食作为原料的时候，技术转换等一系列问题也会随之而来。技术瓶颈仍然是限制我国生物质产业发展的一大因素。我国政府为解决能源短缺问题，缓解环境压力．同时为消化陈粮。在扶持生物质产业发展的过程中一直充当了“埋单者”的角色．这也引发了以粮食为加工原料的燃料乙醇项目的大量上马．粮油价格上涨的趋势开始波及我国。因此。从粮食问题是否让位于能源问题．政府是否继续充当“埋单者”的角色。生物质产业污染治理的角度出发．认为：今后发展生物质产业不能只盯住能源短缺的问题而忽视粮食安全问题。要从技术层面解决原料限制和成本过商的难题。同时政府对生物质产业发展应有科学规划和管理。     

枯草芽孢杆菌对铜绿微囊藻抑制效果的研究

为探讨枯草芽孢杆菌(Bacillus subtilis)对铜绿微囊藻(Microcystis aeruginosa)的抑制效果,在实验室条件下,研究了枯草芽孢杆菌不同生长时期(延迟期、对数期、稳定期和衰亡期)无菌滤液对铜绿微囊藻生长的影响、枯草芽孢杆菌抑制铜绿微囊藻生长的作用方式以及无菌滤液影响下铜绿微囊藻丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性和光合色素含量的变化.结果显示:枯草芽孢杆菌对数期、稳定期和衰亡期滤液抑藻效果明显好于延迟期,作用第8d,对铜绿微囊藻的去除率分别达到81.19%、91.41%、91.82%;4个处理组铜绿微囊藻的叶绿素a含量均显著低于对照组.添加稳定期滤液后,铜绿微囊藻MDA含量显著升高,SOD活性先升高后降低;在对光合色素的影响中,类胡萝卜素受到的影响不如叶绿素a显著.结果表明,枯草芽孢杆菌对铜绿微囊藻的抑制效果是通过分泌胞外物质实现的,且分泌物具有很强的热稳定性.推测该胞外分泌物能够破坏光合色素,影响光合作用,抑制藻细胞的生长;同时抑制SOD活性,使细胞膜脂过氧化程度不断加深,进而破坏藻细胞的完整性,表现出对藻很强的抑制效果.     

规范变换降维与误差修正结合的环境系统的一元线性回归预测

针对高维、非线性环境系统的传统预测模型存在结构复杂、收敛速度慢、求解精度低的局限,提出对环境系统预测量及其影响因子进行幂函数与对数函数相结合的规范变换.此规范变换能使变换后的各影响因子皆等效于一个线性化的规范因子,从而将多因子、非线性的预测建模简化为简单的一个"等效"规范因子的一元线性回归建模;并对预测样本的模型输出进行误差修正,以提高样本的预测精度.在规范变换的基础上,由有m个规范因子的每个建模样本生成一个规范因子的m个"等效"训练样本,n个建模样本共生成N=m×n个训练样本.应用最小二乘法,建立基于规范变换的一元线性回归预测模型.将基于规范变换的一元线性回归预测模型与相似样本误差修正法相结合,分别用于某市5个点位的SO_2浓度预测和南昌市城市降水酸度pH值预测及某河段COD_(Mn)预测,并与多种传统预测模型和方法及基于规范变换与误差修正的3种智能预测模型的预测结果进行了比较.结果表明:该预测模型用于3个实例预测的相对误差绝对值的平均值分别为1.14%、0.49%和1.45%;最大相对误差绝对值分别为2.22%、0.87%和1.85%,与基于规范变换与误差修正的3种智能预测模型的相应误差几乎没有差异,甚至还要小;均远小于多种传统预测模型和方法的相应误差,其预测精度甚至提高了一个数量级以上.基于规范变换与误差修正的一元线性回归预测模型简单、预测精度高、稳定性好,不存在"维数灾难",因而可广泛用于任意系统的预测建模.     

Effects of uncertainty and variability on population declines and IUCN Red List classifications

The International Union for Conservation of Nature (IUCN) Red List Categories and Criteria is a quantitative framework for classifying species according to extinction risk. Population models may be used to estimate extinction risk or population declines. Uncertainty and variability arise in threat classifications through measurement and process error in empirical data and uncertainty in the models used to estimate extinction risk and population declines. Furthermore, species traits are known to affect extinction risk. We investigated the effects of measurement and process error, model type, population growth rate, and age at first reproduction on the reliability of risk classifications based on projected population declines on IUCN Red List classifications. We used an age‐structured population model to simulate true population trajectories with different growth rates, reproductive ages and levels of variation, and subjected them to measurement error. We evaluated the ability of scalar and matrix models parameterized with these simulated time series to accurately capture the IUCN Red List classification generated with true population declines. Under all levels of measurement error tested and low process error, classifications were reasonably accurate; scalar and matrix models yielded roughly the same rate of misclassifications, but the distribution of errors differed; matrix models led to greater overestimation of extinction risk than underestimations; process error tended to contribute to misclassifications to a greater extent than measurement error; and more misclassifications occurred for fast, rather than slow, life histories. These results indicate that classifications of highly threatened taxa (i.e., taxa with low growth rates) under criterion A are more likely to be reliable than for less threatened taxa when assessed with population models. Greater scrutiny needs to be placed on data used to parameterize population models for species with high growth rates, particularly when available evidence indicates a potential transition to higher risk categories.     

Dynamic Performance of Horizontal Flexible Anchor Lines During Fall Arrest— A Numerical Method of Simulation

Designing fall arrest systems, which contain horizontal flexible anchor lines is an important technical problem related to the safety of people who work at a height and need horizontal freedom of movement. The article presents a numerical simulation of the dynamic performance of horizontal flexible anchor lines during fall arrest. The model of a 2-component system—a horizontal flexible anchor line and a falling rigid mass, described with a second order non-linear differential equation—is the main element of this method. This method of simulation is realised by a computer program, which allows obtaining the most important data characterising a fall arrest. The article shows laboratory tests used for the verification of this method, which turned out to be a valuable source of information and which can be used for designing fall arrest systems.