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621.
GC-MS测定土壤中阿特拉津、六氯苯等十种农药残留   总被引:2,自引:0,他引:2  
建立了气相色谱-质谱-选择离子监测(GC-MS-SIM)同时测定土壤中10种农药(三嗪类除草剂、酰胺类除草剂和有机氯农药)的多残留分析方法.样品采用正己烷/丙酮(1:1,V/V)超声提取、氟罗里硅土柱层析净化、GC-MS-SIM测定.10种农药在0.01(0.02)-1.0(2.0)mg·l~(-1)范围内线性良好,相关系数介于0.9963-0.9998之间;在10,50和250 ng·g~(-1)添加水平下,平均回收率介于81%-117%之间,相对标准偏差均小于14.4%;方法检出限达到ppb至sub-ppb级(0.1-1.3 ng·g~(-1)).将此方法应用于辽宁省不同性质土壤中70个实际土壤样品的分析,阿特拉津、乙草胺、六氯苯、丁草胺、狄氏剂和艾氏剂有检出,该法对不同性质土壤具有广泛适用性.  相似文献   
622.
Proteomics involves the separation of proteins, identification of the amino acid sequence of the interested or target proteins, study of the function of the proteins, modification, structure and ultimate assignments to functional pathways in the cell. The proteomic investigations have contributed greatly to human diseases studies, new drugs discovery researches, and environmental science in recent years. This article provides a review on the development of the main proteomic technologies, including both the gel based and non-gel based technologies, and their applications in environmental science. Proteomic technologies have been utilized in the environmental stresses studies to analyze the induction or reduction of proteins at expression level and identify the target proteins to investigate their function in response to environmental stresses, such as high or low pH, oxidation stress, and toxic chemicals. Such protein responses are also helpful to understand the mechanisms of some cellular activities and the functions of some proteins.  相似文献   
623.
程梦婷  刘倩  刘稷燕  江桂斌 《环境化学》2014,(10):1733-1743
石墨烯是一种全部由碳六元环构成的新型二维碳纳米材料.从2004年发现至今,其在能源、电子、复合材料、生物医学等领域中的应用都取得了重大研究进展.近年来,石墨烯在分析化学领域也表现出了巨大的应用潜力,尤其是在环境有机污染物分析方面,涌现了大量相关报道.本文简要回顾了近期石墨烯在环境有机污染物分析中的应用情况,涵盖了样品前处理、色谱、传感器、质谱等不同的技术方向,并对石墨烯在环境分析中的应用前景进行了展望.  相似文献   
624.
薇甘菊(Mikaniamicrantha H.B.Kunth)为世界上最具有入侵性和危害性的外来入侵物种之一,对其控制与管理已成为长期以来世界性难题。了解入侵植物薇甘菊在异质环境下的适应性与繁殖特性对安全有效预警、监测和防治该入侵物种具有重要意义。本文于薇甘菊盛花期,根据薇甘菊入侵生境的光照条件、群落结构和生长方式差异,在薇甘菊常见的4种入侵生境(林地、荒地、农田和和河边)选取10个样地,调查研究了不同生境条件下薇甘菊的开花结实和繁殖分配,并运用植物叶片功能性状的研究方法研究了不同生境条件下薇甘菊的比叶面积(SLA)、叶干物质比例(LMF)和茎干物质比例(SMF)的3种叶片功能性状。研究结果表明,生境条件对薇甘菊的开花结实和繁殖分配具有显著影响。其中抛荒农田(样地Ⅷ)和河流边缘(样地Ⅸ和Ⅹ)薇甘菊的总花数、种子量、生殖枝茎生物量分配和花生物量分配均显著大于其他生境,显示在有利于其生长的条件下,薇甘菊种群倾向于有性繁殖;而在不利于薇甘菊生长的低光照林地(样地Ⅰ)和种间竞争强的农田红薯地(样地Ⅵ)生境条件下,薇甘菊的总花数和种子量明显小于其他生境,但营养枝叶生物量分配显著大于其他样地,而茎生物量分配值则处于中间值,表明在不利于其生长的生境条件下,薇甘菊通过提高营养枝茎的生物量分配和叶的生物量分配来适应,其种群则更倾向于克隆繁殖。通过分析不同生境条件下薇甘菊的叶片功能性状,结果表明,在不利于薇甘菊生长的低光照林地(样地Ⅰ)和种间竞争强的农田红薯地(样地Ⅵ)生境条件下,薇甘菊的叶面积和茎干物质比例(SMF)显著小于其他样地,且彼此差异不显著;但比叶面积(SLA)和叶干物质比例(LMF)则显著大于其他样地,显示薇甘?  相似文献   
625.
The prosperity and well-being of human societies relies on healthy ecosystems and the services they provide. However, the biodiversity crisis is undermining ecosystems services and functions. Vultures are among the most imperiled taxonomic groups on Earth, yet they have a fundamental ecosystem function. These obligate scavengers rapidly consume large amounts of carrion and human waste, a service that may aid in both disease prevention and control of mammalian scavengers, including feral dogs, which in turn threaten humans. We combined information about the distribution of all 15 vulture species found in Europe, Asia, and Africa with their threats and used detailed expert knowledge on threat intensity to prioritize critical areas for conserving vultures in Africa and Eurasia. Threats we identified included poisoning, mortality due to collision with wind energy infrastructures, and other anthropogenic activities related to human land use and influence. Areas important for vulture conservation were concentrated in southern and eastern Africa, South Asia, and the Iberian Peninsula, and over 80% of these areas were unprotected. Some vulture species required larger areas for protection than others. Finally, countries that had the largest share of all identified important priority areas for vulture conservation were those with the largest expenditures related to rabies burden (e.g., India, China, and Myanmar). Vulture populations have declined markedly in most of these countries. Restoring healthy vulture populations through targeted actions in the priority areas we identified may help restore the ecosystem services vultures provide, including sanitation and potentially prevention of diseases, such as rabies, a heavy burden afflicting fragile societies. Our findings may guide stakeholders to prioritize actions where they are needed most in order to achieve international goals for biodiversity conservation and sustainable development.  相似文献   
626.
Kendrick mass defect was used for PFASs screening in textile finishing agents (TFAs). Total oxidizable precursor assay provides insight into unknown precursors. Perfluorooctane sulfonate was found as impurity in short ECF technology based TFAs. Perfluorooctanoate was also detected in C6 telomerization based TFAs. Long chain precursors were also observed in both types of TFAs. Organofluorinated surfactants are widely employed in textile finishing agents (TFAs) to achieve oil, water, and stain repellency. This has been regarded as an important emission source of per-and polyfluoroalkyl substances (PFASs) to the environment. China is the biggest manufacturer of clothes, and thus TFA production is also a relevant industrial activity. Nevertheless, to date, no survey has been conducted on PFAS contents in commercially available TFAs. In the present study, TFA products were investigated by the Kendrick mass defect method. The quantification results demonstrated a significant presence of perfluorooctane sulfonate (0.37 mg/L) in TFAs manufactured by electrochemical fluorination technology. The products obtained by short-chain PFAS-based telomerization were dominated by perfluorooctanoic acid (mean concentration: 0.29 mg/L), whose values exceeded the limits stated in the European Chemical Agency guidelines (0.025 mg/L). Moreover, the total oxidizable precursor assay indicated high levels of indirectly quantified precursors with long alkyl chains (C7–C9). Together, these results suggest that there is currently a certain of environmental and health risks in China that originates from the utilization of TFAs, and a better manufacturing processes are required to reduce such risks.  相似文献   
627.
采用甲醇提取-吹扫捕集的前处理方法并结合气相色谱-质谱仪来测定土壤样品中的8种苯系物。实验结果表明,8种苯系物在前处理过程中被有效提取出来并被准确定性和定量,对于低浓度样品也具有良好的实验效果。此方法的检出限为0.3~0.8μg/kg,测定下限为1.2~3.2μg/kg。加标低、中、高3种不同质量比的标准物质,经实验分析土壤中8种苯系物相对标准偏差(RSD)为2.1%~6.8%,加标回收率为91.0%~105%,与相关行业标准相比具有一定的优势。  相似文献   
628.
某大型地下洞室群围岩稳定性工程地质评价   总被引:1,自引:0,他引:1  
某水电站布置有大型的地下洞室群,其规模在国内外已建和拟建的工程中都是十分罕见的。总体上说,地下厂房区岩体质量较好,但由于多期的构造作用,在厂房区岩层中发育有不同级别的结构面,对围岩的稳定性有一定影响。对此,本文运用围岩分类法和数值模拟法分析了厂房开挖后围岩的整体稳定性,然后运用UNWEDGE软件对主厂房顶拱部位的不稳定块体进行了分析评价。  相似文献   
629.
• A model coupling water-heat-salt of unsaturated frozen soil was established. • Future temperature, precipitation, and evaporation increase in freeze–thaw period. • Soil water, heat, and salt transport are closely coupled during freeze–thaw period. • Freeze–thaw cycles and future climate change can exacerbate salinization. The transport mechanisms of water, heat, and salt in unsaturated frozen soil, as well as its response to future climate change are in urgent need of study. In this study, western Jilin Province in north-eastern China was studied to produce a model of coupled water-heat-salt in unsaturated frozen soil using CoupModel. The water, heat, and salt dynamics of unsaturated frozen soil under three representative concentration pathway (RCP) scenarios were simulated to analyze the effects of future climate change on unsaturated frozen soil. The results show that water, heat, and salt migration are tightly coupled, and the soil salt concentration in the surface layer (10 cm) exhibits explosive growth after freezing and thawing. The future (2020–2099) meteorological factors in the study area were predicted using the Statistical Downscaling Model (SDSM). For RCP2.6, RCP4.5, and RCP8.5 scenarios, future temperatures during the freeze–thaw period increased by 2.68°C, 3.18°C, and 4.28°C, respectively; precipitation increased by 30.28 mm, 28.41 mm, and 32.17 mm, respectively; and evaporation increased by 93.57 mm, 106.95 mm, and 130.57 mm, respectively. Climate change will shorten the freeze–thaw period, advance the soil melting time from April to March, and enhance water and salt transport. Compared to the baseline period (1961–2005), future soil salt concentrations at 10 cm increased by 1547.54 mg/L, 1762.86 mg/L, and 1713.66 mg/L under RCP2.6, RCP4.5, and RCP8.5, respectively. The explosive salt accumulation is more obvious. Effective measures should be taken to prevent the salinization of unsaturated frozen soils and address climate change.  相似文献   
630.
基于城市汽车年检中CO2的过程动态检测数据,对小型汽油客车CO2的排放因子和排放水平信息进行了挖掘,并与文献研究结果进行了对比.结果表明,从城市汽车年检数据中挖掘的CO2排放结果可以作为研究城市机动车碳排放的重要参考依据;合理有效地利用汽车年检数据可以为城市车辆尾气排放的精准分级管控、城市交通运输碳排放达峰的量化分析,以及城市交通源的污染物和CO2协同减排提供重要的数据支撑;从国Ⅰ到国Ⅴ不同排放阶段汽油车的常规污染物CO、NOx和HC的排放水平下降非常明显,而对应的CO2排放水平差异不大;CO2排放因子随累计行驶里程、车龄、基准质量和排量的变化关系反映出,如果需要削减城市汽车碳排放水平,应鼓励使用基准质量小或者排量小的车辆,淘汰高油耗高排放的老旧车辆,鼓励公共绿色出行而降低单车活动水平,增加纯电动车辆优化车队能源结构.  相似文献   
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