影响土壤电动力学修复技术的主要因素

综述了影响土壤电动修复的几个主要因素，如土壤的pH值、Zeta电位、极化问题、化学性质以及含水率等等，并提出了一些可行性解决措施。如能解决好这几个问题，必将加速土壤电动修复的研究进展。     

Adsorption of soluble oil from water to graphene

The toxicity of soluble oil to the aquatic environment has started to attract wide attention in recent years. In the present work, we prepare graphene according to oxidation and thermal reduction methods for the removal of soluble oil from the solution. Characterization of the as-prepared graphene are performed by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman spectra, Brunauer-Emmett-Teller, X-ray photoelectron spectroscopy, and contact angle analysis. The adsorption behavior of soluble oil on graphene is examined, and the obtained adsorption data are modeled using conventional theoretical models. Adsorption experiments reveal that the adsorption rate of soluble oil on graphene is notably fast, especially for the soluble diesel oil, which could reach equilibrium within 30 min, and the kinetics of adsorption is perfectly consistent with a pseudo-second-order model. Furthermore, it is determined that the adsorption isotherm of soluble diesel oil with graphene fit the Freundlich model best, and graphene has a very strong adsorption capacity for soluble diesel oil in the solution. These results demonstrate that graphene is the material that provided both good adsorptive capacity and good kinetics, implying that it could be used as a promising sorbent for soluble oil removal from wastewater.     

Distribution characteristics and indicator significance of Dechloranes in multi-matrices at Ny-Ålesund in the Arctic

In recent years, Dechloranes have been widely detected in the environment around the world. However, understanding and knowledge of Dechloranes in remote regions, such as the Arctic, remain lacking. Therefore, the concentrations of 5 Dechloranes in surface seawater, sediment, soil, moss, and dung collected from Ny-Ålesund in the Arctic were measured with the concentrations 93 pg/L, 342, 325, 1.4, and 258 pg/g, respectively, which were much lower than those in Asian and European regions. The mean ratios of anti-Dechlorane Plus (DP) to total DP (?_anti) in seawater, sediment, soil, moss, dung, and atmospheric samples were 0.36, 0.21, 0.18, 0.27, 0.66, and 0.43, respectively. Results suggested that the main source of DP in seawater, sediment, soil, and moss was long-range atmospheric transport. However, the ratio identified in dung was different, for which the migration behavior of the organism is probably the main source of DP.     

全氟辛烷磺酸(PFOS)对半滑舌鳎肝脏细胞的毒性效应

为探究海洋环境中持久性有机污染物——全氟辛烷磺酸(PFOS)的生物毒性效应,以半滑舌鳎肝脏细胞(HTLC)为研究对象,将其暴露于含不同浓度PFOS的DMEM-F12培养基中,分别染毒24、48、72 h后,利用噻唑蓝比色法(MTT)和透射电镜实验评价PFOS的细胞毒性;同时测定活性氧自由基(ROS)和超氧化物歧化酶(SOD)活性来探讨PFOS对细胞的氧化损伤效应。结果发现,细胞活性随PFOS浓度升高呈先促进后抑制趋势,当PFOS浓度达到1 000%mol·L-1时细胞活性受到显著抑制(P0.01);电镜结果显示PFOS能引起与代谢相关的细胞器如线粒体、内质网等发生肿胀甚至破损;与对照组相比,ROS含量和SOD活性分别在20%mol·L-1、200%mol·L-1开始出现显著性差异(P0.05),证实在PFOS引起的氧化应激反应中SOD起到了清除自由基作用以维持细胞稳态。研究表明,PFOS对海洋鱼类细胞具有一定的生物毒性,能引起细胞产生氧化应激反应,并进一步破坏生物膜系统,从而导致细胞增殖和多种代谢途径受到抑制。     

淡水水生态基准方法学研究:繁殖/生殖毒性类化合物水生态基准探讨

繁殖/生殖毒性类化合物由于特殊的毒理作用模式(mode of action,MOA),通过影响生物繁衍影响到种群和群落,因此依靠基于急、慢性毒性测试终点和传统基准推导方法推导的水生态基准值并不能够为水生生物群落结构提供足够的保护。本文根据文献资料,分析了推导此类化合物水生态基准时的关键科学问题,包括繁殖/生殖毒性类化合物MOA,毒性数据类型,受试物种选择,以及不同生命阶段、多代毒性测试和测试终点的判别和选择。并用所收集的壬基酚数据,尝试推导了基于水生生物生殖毒性的水生态基准值。研究得出基于生殖毒性的壬基酚预测无观察效应浓度(PNEC)值为0.12μg·L-1,其数值比美国环境保护局根据传统基准方法推导的基准持续浓度(CCC)的6.59μg·L-1低了近50倍。因此,基于其繁殖毒性(包括产卵量、受精率、孵化率、多代效应以及种群变化等)的实验结果更适合用于具有繁殖/生殖毒性污染物水生态基准的推导。     

流动沙漠地形起伏区尼龙网方格沙障破损程度的空间分异

在塔克拉玛干沙漠油田公路K287 km处,对设置在纵向复合沙垄区次级新月形沙丘上不同地貌部位的尼龙网方格沙障破损状况进行了调查研究,并对破损程度进行了综合评价。研究结果表明,(1)平沙地上的尼龙网方格沙障破损类型相对单一,以半埋型式为主;流动沙丘上的尼龙网方格沙障破损类型多样,而且不同地貌部位的破损类型不同。(2)沙丘个体及不同地貌部位的破损程度值远远高于平沙地,破损程度值排序为迎风坡脚迎风坡中部沙丘两翼落沙坡迎风坡中上部丘顶。(3)沙丘不同地貌部位尼龙网方格沙障受损的空间分异主要与沙丘对近地表风流场的强烈扰动有关。(4)尼龙网方格沙障更适宜布设在平坦的地形,提高尼龙网方格沙障对地形起伏适应性的关键在于其布设模式以及布设配件的改进。     

滇池周边地区农田土壤硝酸盐迁移累积特征

采用实地调查与模拟实验相结合的方法,研究不同施氮水平对地表水及土体中硝态氮迁移和累积的影响,旨在为减轻硝酸盐对滇池环境的威胁提供科学依据.结果表明,流域内农田排水中氮污染负荷高、氮肥投入过量及灌水频繁是造成研究区内土壤硝酸盐淋洗污染地下水的主要原因;土壤中NO3--N累积量与氮肥施用量在生菜的苗期呈极显著正相关(相关系数R0.01=0.9687**,**表示极显著线性相关),而在结球期呈显著正相关(R0.05=0.887*,*表示显著线性相关);在生菜整个生育期里,NO3--N沿土壤剖面垂直迁移至土壤深层,导致下层土壤的NO3--N含量高于上层土壤;生菜在苗期NO3--N淋失量较大,对地下水污染的风险高;高施氮强度与低施氮强度相比,氮素更易流失;频繁灌溉促使NO3--N随水向深层土壤迁移累积.     

国家可持续发展实验区科技计划实施现状及成效

国家可持续发展实验区是我国实施可持续发展战略的重要实验示范基地。多年来,秉承科技支撑发展的原则,实验区开展了一系列科技创新及实验示范。在对现有实验区开展实地调研和问卷调查的基础上,从计划类别、经费来源、参与形式、应用领域等方面,分析了"十一五"以来实验区承担的各类科技计划项目实施现状,并对项目实施成效进行了总结分析。分析发现,实验区承担的各类科技计划项目,通过破解区域发展制约因素,取得显著社会效益;突出科技示范与引领,科技支撑能力不断提升;创新了管理机制与模式,积累了丰富的项目管理经验;通过部门联动,科技惠民计划成效凸显。文章通过探寻科技在实验区建设中的引领和带动作用,发现实验区项目对接的特点与规律,查找实验区科技创新存在的问题与不足,提出了科技支撑实验区发展的对策与建议。     

Nest site selection in the open-nesting honeybee Apis florea

We studied nest site selection by swarms of the red dwarf honeybee, Apis florea. By video recording and decoding all dances of four swarms, we were able to determine the direction and distances indicated by 1,239 dances performed by the bees. The bees also performed a total of 715 nondirectional dances; dances that were so brief that no directional information could be extracted. Even though dances converged over time to a smaller number of areas, in none of the swarms did dances converge to one site. As a result, even prior to lift off, bees performed dances indicating nest sites in several different directions. Two of four swarms traveled directly in what seemed to be the general direction indicated by the majority of dances in the half hour prior to swarm lift off. The other two traveled along circuitous routes in the general direction indicated by the dances. We suggest that nest site selection in A. florea has similar elements to nest site selection in the better-studied Apis mellifera. However, the observation that many more locations are indicated by dances prior to lift off also shows that there are fundamental differences between the two species.     

中国域际关键自然资本竞争效应的测算与分析

以生产生态足迹核算法为基础,引入关键自然资本概念,计算全国32个地区1949至2007年的3类自然资源的本区域生态足迹,即生产性土地、水资本及能源足迹,核算时将水产品、淡水及水电统一在水足迹项下,并对生产性土地和能源足迹的核算口径作相应调整。在此基础上,继而测算关键自然资本竞争效应,从全局及个案2个角度分析区域发展战略对区域关键自然资本竞争效应的影响。这里关键自然资本竞争效应是对区域自然资本禀赋开采活动的抽象,描述战略期内某区域自然资本开采量调整幅度较同期平均水平的相对情况。全局分析,即比较东、中、西部地区1949至1979年非倾向性区域战略、1980至1997年东部倾向性战略和1998至2007年中、西部倾向性战略期的关键自然资本竞争效应,结果显示：关键自然资本竞争效应的调整方向与区域战略倾斜方向相同,第一次调整为东部倾斜,对应着东部境内关键自然资本竞争效应的上升,第二次调整为中、西部倾斜政策,对应着中、西部境内关键自然资本的上升。南水北调工程作为个案分析,补充论述资源再配置工程对关键自然资本竞争效应的影响,通过比较南水北调东、中线相关区域关键自然资本变动情况发现：水源区自然资本生产力下降;不可持续开采方式的负外部性有从＂点＂向工程沿线扩展的可能。