建议在我国开展累积影响评价的理论与实践研究

阐述了可持续发展目标要求下传统环境影响评价制度的弊端,分析了累积影响评价与可持续发展的关系以及进行累积影响评价的必要性,回顾了国内外累积影响评价研究的现状,论述了在我国开展累积影响评价研究的目的、研究内容和研究方法。      

外加热辐射时不同浓度聚丙烯酸钠胶体的实验研究

本文利用锥形量热仪的三个不同外加的热辐射强度,对不同浓度的聚丙烯酸钠胶体的热辐射物理属性进行了实验研究,得到了在不同的热辐射强度下不同浓度的聚丙烯酸钠胶体的失水及对热辐射吸收的实验数据,并总结了各自的规律。从热辐射属性的角度分析了肢体用作灭火剂的原因。     

Arsenite oxidation by three types of manganese oxides

Oxidation of As（Ⅲ） by three types of manganese oxides and the effects ofpH, ion strength and tartaric acid on the oxidation were investigated by means of chemical analysis, equilibrium redox, X-ray diffraction （XRD） and transmission electron microscopy （TEM）. Three synthesized Mn oxide minerals, bimessite, cryptomelane, and hausmannite, which widely occur in soil and sediments, could actively oxidize As（Ⅲ） to As（Ⅴ）. However, their ability in As（Ⅲ）-oxidation varied greatly depending on their structure, composition and surface properties. Tunnel structured cryptomelane exhibited the highest ability of As （Ⅲ） oxidation, followed by the layer structured birnessite and the lower oxide hausmannite. The maximum amount of As （Ⅴ） produced by the oxidation was in the order （mmol/kg） of cryptomelane （824.2） 〉 bimessite （480.4） 〉 hausmannite （117.9）, As pH increased from the very low value（pH 2.5）, the amount of As（Ⅲ） oxidized by the tested Mn oxides was firstly decreased, then negatively peaked in pH 3.0 6.5, and eventually increased remarkably. Oxidation of As（Ⅲ） by the Mn oxides had a buffering effects on the pH variation in the solution. It is proposed that the oxidative reaction processes between As （Ⅲ） and biruessite（or cryptomelane） are as follows： （1） at lower pH condition： （MnO2）x＋ H3AsO3 ＋ 0.5H^＋=0.5H2AsO4^- ＋ 0.5HAsO4^2- ＋Mn〉^2＋ （MnO2）x-1 ＋ H2O; （2） at higher pH condition： （MnO2）x ＋ H3AsO3 = 0.5H2AsO4^- ＋ 0.5HAsO4^2- ＋ 1.5H^＋ ＋ （MnO2）x-1. MnO. With increase of ion strength, the As（Ⅲ） oxidized by bimessite and cryptomelane decreased and was negatively correlated with ion strength. However, ion strength had little influence on As （Ⅲ） oxidation by the hausmarmite. The presence of tartaric acid promoted oxidation of As（Ⅲ） by birnessite. As for cryptomelane and hansmannite, the same effect was observed when the concentration of tartaric acid was below 4 mmol/L, otherwise the oxidized As（Ⅲ） decreased. These findings are of great significance in improving our understanding of As geochemical cycling and controlling As contamination.     

氟碳表面活性剂对空心微珠三相泡沫抗溶抗烧性能影响研究

研究了氟碳表面活性剂添加量、氟碳表面活性剂性质和泡沫液浓度等对空心微珠三相泡沫在油面稳定性的影响,并在模拟燃烧装置上对比了添加氟碳表面活性剂前后三相泡沫的抗烧能力.结果表明,加入氟碳表面活性剂后,三相泡沫在油面的稳定性显著增强,且阴离子氟碳表面活性剂优于阳离子和两性离子表面活性剂.当阴离子氟碳表面活性剂、空心玻璃微珠和蛋白泡沫浓度分别为0.02%、6%和10%时,三相泡沫受热后表面形成黑色致密覆盖层,可有效隔绝热量向内部传递,使抗烧性得到明显提高.     

大跨度黄土隧道CRD法优化研究

针对大跨度隧道通常采用的交叉中壁(CRD)法的工法特点,以V级围岩条件下的某大跨度黄土隧道为研究对象,采用有限元数值模拟手段,对CRD工法中各个分部的开挖形状、开挖顺序以及支护形式进行了优化研究。研究结果表明,将传统CRD法的开挖顺序调整为CRD1-CRD3-CRD2-CRD4时,隧道各步位移及初期支护内力均较原CRD法要小;当采用直线型临时支护代替曲线型临时支护时,隧道初期支护内力会有一定幅度增大,但变化幅度小于10%。优化后的CRD法可以减少工序,加快大跨度黄土隧道的施工进度,提高经济效益。     

嫩江下游土地沙化的时空变化——基于MODIS数据的遥感分析

以2000,2004和2008年的MODIS数据为主要数据源,以嫩江流域下游为研究对象,在Arc-GIS9.0和ERDAS IMAGE9.0等软件支持下,建立沙化模型,并对沙化进行了信息提取与分析;借助ArcGIS强大的空间分析功能,完成了土地沙漠化的定量分析及其时空变化规律,在此基础上进一步探讨了土地沙化的过程、机理和成因.结果表明:研究区域沙漠化土地以轻度和中度沙漠化土地为主;重度和极重度沙漠化土地的年增长率较大,水域的年减少率最大;重度、极重度沙漠化土地主要向较低等级的沙漠化土地和水域转变,呈现一定的逆转移.     

Preparations of TiO2 film coated on foam nickel substrate by sol-gel processes and its photocatalytic activity for degradation of acetaldehyde

Anatase TiO2 films were successfully prepared on foam nickel substrates by sol-gel technique using tetrabutyl titanate as precursor. The characteristics of the TiO2 films were investigated by XPS, XRD, FE-SEM, TEM and UV-Vis absorption spectra. The photocatalytic activities of TiO2 films were investigated by photocatalytic degradation reactions of gaseous acetaldehyde, an indoor pollutant, under ultraviolet light irradiation. It was found that Ni^2＋ doping into TiO2 films due to the foam nickel substrates resulted in the extension of absorption edges of TiO2 films from UV region to visible light region. The pre-heating for foam nickel substrates resulted in the formation of NiO layer, which prevented effectively the injection of photogenerated electrons from TiO2 films to metal nickel. The TiO2 films displayed high photocatalytic activity for the degradation of acetaldehyde, and were enhanced by calcining the substrates and coating TiO2 films repeatedly. The high activity was mainly attributed to the improvement of the characteristics of substrate surface and the increase of active sites on photocatalyst.     

厦门市近岸海域水环境抗生素抗性基因污染分布特征

海岸带及毗连海岛是人类经济社会发展的热点区域,城市化、工业化和农业活动等人类活动对近岸海域水环境生态环境产生了深刻的影响. 抗生素抗性基因（ARGs）作为一种新污染物,是当前水生态安全研究和公共关注的热点,但是近岸海域水环境ARGs污染研究比较匮乏. 基于厦门市近岸海域地理环境特征,采用高通量定量PCR技术,深入研究了近岸海域水环境中抗生素抗性基因的种类丰度水平和分布格局. 并结合16S rDNA基因扩增子测序方法,探究了水体环境微生物群落结构与组成,深入阐释了近岸海域抗生素抗性基因的影响因素和赋存变化机制. 结果表明,近岸海域水体环境总共检测出187种抗生素抗性基因,丰度水平高达1.29×10¹⁰ copies·L^-1,多重耐药类、氨基糖苷类和β内酰胺类是厦门市近岸海域水体环境最主要的3大类抗生素抗性基因,整体上呈现出丰度较高、种类多样以及普遍共存的特点,近岸海域水环境是抗生素抗性基因分布的重要热区和储存库;Nautella、Candidatus、Tenacibaculum、Rubripirellula和Woeseia等22种微生物是相应16种抗生素抗性基因的潜在携带者,可移动遗传元件（MGEs）和微生物群落结构对近岸海域水体环境抗性基因变化的综合解释量达到了93.9%,说明微生物群落及其可移动遗传元件是近岸海域水体抗生素抗性基因赋存和演化最重要的驱动力. 以上研究结果说明,厦门市近岸海域水体环境抗生素抗性基因具有潜在的水生态安全及人类健康风险,能够为近岸海域水体环境微生物及ARGs污染控制提供科学支撑.     

地表水样品中10种卤代烃测定方法的优化

对地表水样品中10种卤代烃测定方法进行优化,找出空白偏高的原因。方法优化后的加标回收率为90.1%~104%,相对标准偏差为1.1%~6.9%,检出限为0.000 3μg/L~2.0μg/L,可满足地表水环境质量分析要求。     

水钠锰矿的锰氧化度与Pb~(2+)吸附量的关系

研究水钠锰矿对重金属离子的吸附,其结构中八面体空穴特点与重金属离子吸附的关系是人们关注的热点.采用酸性和碱性2种介质条件合成了具有不同锰氧化度的2个系列水钠锰矿,研究了它们的锰氧化度(average oxidation state of Mn, AOS)与其d110面网间距和Pb2+的最大吸附量的关系,以及Pb2+吸附量与Mn2+、H+和K+释放量的关系.结果表明,同系列的水钠锰矿具有相似的晶体形貌,它们的锰氧化度与其d110面网间距呈极显著的负相关(r =-0.9035<-0.6614,n=14,α=0.01),而与Pb2+的最大吸附量呈极显著的正相关(r=0.9779>0.6614,n=14,α=0.01),供试水钠锰矿锰氧化度的高低表观上反映了结构中八面体空穴数量的多少,水钠锰矿随着锰氧化度的提高,导致其结构中的八面体空穴数增多,对Pb2+的吸附容量增大,八面体空穴数量对Pb2+的吸附量的大小起着非常重要的作用.Pb2+的吸附量与吸附过程中Mn2+、H+和K+的释放量之和呈极显著的正相关(r = 0.9962 > 0.6614,n = 14,α = 0.01),Pb2+吸附过程中伴随的Mn2+、H+和K+的释放主要来自于水钠锰矿结构中八面体空穴处吸附的相应阳离子.吸附前Mn2+,Mn3+与H+、K+占据水钠锰矿结构中八面体空穴上下方位点的相对多少受水钠锰矿的锰氧化度高低的影响,锰氧化度低时,八面体空穴上下方位点吸附Mn2+、Mn3+较多,吸附的H+、K+则较少,反之亦然.