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181.
Journal of Polymers and the Environment - Magnetic sodium alginate(SA)-based biogel composite Fe-SA-Y@Fe3O4 macroparticles were synthesized by co-crosslinking of Y(III) and Fe(III) ions according...  相似文献   
182.
株洲市臭氧污染状况及相关气象因子分析   总被引:1,自引:0,他引:1  
采用2013年1~12月空气质量自动监测数据对株洲市臭氧污染现状及相关气象因子进行分析。结果表明:监测期间全年臭氧日最大8 h平均浓度一级标准值达标率达到71.8%,全年超标率为1.6%,超标主要出现在季节变换时期。臭氧日最大8 h平均浓度的月均值变化呈"M"型,浓度高值持续时间长。日变化规律较强,且不同季节变化特征略有差别。臭氧浓度与气温有正相关性,相关系数为0.612;与湿度和云量有负相关性,且臭氧与湿度负相关性较明显,相关系数为0.731。  相似文献   
183.
以体外培养人Bel-7402肝癌细胞为模型,研究铅的3种常见化合物氯化铅(Pb Cl2)、乙酸铅(Pb(CH3COO)2)、硝酸铅(Pb(NO3)2)的细胞毒性和去甲基化表观遗传毒性。应用MTS方法检测细胞的存活率,以前期研究建立的评价方法评价铅化合物的去甲基化表观遗传毒性。结果显示,Pb Cl2、Pb(CH3COO)2、Pb(NO3)2均会抑制Bel-7402细胞的增值,计算求得Pb Cl2、Pb(CH3COO)2、Pb(NO3)2相应的50%细胞存活浓度(IC50)值分别为2 524μmol·L~(-1)、1 977μmol·L~(-1)、1 899μmol·L~(-1);80%细胞存活浓度(IC80)值分别为264μmol·L~(-1)、221μmol·L~(-1)、281μmol·L~(-1),通过对3种染毒物不同染毒浓度的细胞存活率进行随机区组设计的方差分析显示3种化合物间的差异无统计学意义(F=0.11;P=0.897)。去甲基化表观遗传毒性检测结果显示,Pb Cl2、Pb(CH3COO)2、Pb(NO3)2均可观察到明显的去甲基化表观遗传毒性,其相对于5-氮杂-2-脱氧胞苷(5-Aza-Cd R)的去甲基化表观遗传毒性当量分别为2.82E-03、1.50E-03、5.09E-04,三者间也无显著性差异。结果表明,铅化合物会使Bel-7402细胞的细胞存活率和转染进细胞的质粒上增强型绿色荧光蛋白基因启动子的DNA甲基化水平下降。  相似文献   
184.
基于非本地物种的毒性数据推导出的水质基准一直存在争议,质疑者提出应有针对不同生物区系的水质基准。而这个问题在中国尤为突出。本文作者搜集了38种污染物对本地物种和非本地物种的毒性数据,比较了这些生物的HC5和物种敏感度分布,结果显示,基于非本地物种推导的水质基准有74%的确定性可以有效保护中国的水生态系统。如果采用评价因子(AF=5)来校正基准,那么可以获得90%的确定性。
精选自Xiaowei Jin, Zijian Wang, Yeyao Wang, Yibing Lv, Kaifeng Rao, Wei Jin, John P. Giesy and Kenneth M. Y. Leung. Do water quality criteria based on nonnative species provide appropriate protection for native species? Environmental Toxicology and Chemistry: Volume 34, Issue 8, pages 1744–1750, August 2015. DOI: 10.1002/etc.2985
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.2985/full  相似文献   
185.
Maintaining soil fertility, while controlling pollution from excessive chemical fertilizer application is important for keeping soil productivity of sustainable agriculture. Variety of straws have been used and proven to be good soil amendments for increasing soil organic matter (OM) and a range of additional soil nutrients. However, little is known about the utilization of cotton straw for soil amendment. To better understand the mechanism behind cotton straw soil amendments, investigations were performed upon cucumber seedlings, where changes to soil nutrients and microbial communities were investigated. The results revealed that the cotton straw application promoted the cucumber seedling growth by significantly increasing the soil OM, available nitrogen, available phosphorus, and available potassium. The concentration of cotton straw was positively correlated to both the number of the culturable microorganisms and also the total microbial biomass within soil. Furthermore, assessment of cotton straw application using Biolog metabolic profiling and phospholipid fatty acid analysis revealed that such application increased the microbial community metabolic activity, and markedly changed the structure of microbial community. 16S rRNA gene clone library construction and phylogenetic analysis of soil bacteria revealed γ- Proteobacteria sequences dominated the cotton straw amendment soil, comprising 27.8% of the total number of analyzed sequences, while they were less represented in control soil (13.4%). On the contrary, the Sphingobacteria (7.8%) and Verrucomicrobia (2.4%) in the cotton straw amendment soil decreased after application when compared to the control soil 15.2% and 15.2%.  相似文献   
186.
研究了不同浓度铀(0.1、1.0、10.0和30.0mg·L-1)胁迫对满江红鱼腥藻(Anabaena azollae)和爪哇伪枝藻(Scytonemaj avanicum)生长及抗氧化酶活性的影响。结果表明,低浓度铀(0.1和1.0mg·L-1)条件下,两种蓝藻的超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性及丙二醛(MDA)含量均无明显变化;叶绿素a含量和可溶性蛋白质含量均较对照上升,表明低浓度铀对A.azollae和S.javanicum均未形成明显胁迫,对生长表现为刺激和促进作用。10.0mg·L-1浓度的铀对A. azollae的生长影响不大,对S. javanicum却产生了明显的抑制作用。30.0mg·L-1铀胁迫下,两种蓝藻中的MDA显著增加,抗氧化酶系统受到破坏,生长严重受阻。实验结果显示,A. azollae和S. javanicum的耐铀极限分别在10.0~30.0mg·L-1和1.0~10.0mg·L-1之间,A. azollae的抗铀性比S. javanicum强。  相似文献   
187.
Assuming that a set of constant parameters fits for marine ecosystem modeling and parameter estimation studies on large space scales is questionable since ecosystem types spanning long distances are quite different. In this study, SeaWiFS chlorophyll-a data are assimilated into a simple NPZD model by the adjoint method in a climatological physical environment provided by FOAM. To improve the assimilation results, different spatial parameterization schemes are utilized. The results show that the values of the selected sensitive parameters are spatially variable and the application of spatial parameterizations can improve the assimilation results significantly.  相似文献   
188.
Chen  Rui  Wang  Qi  Lv  Jungang  Wang  Zongshuang  Gao  Tao 《Environmental geochemistry and health》2021,43(9):3485-3503
Environmental Geochemistry and Health - A total of 475 representative cultivated land and 435 crop samples from 11 provinces of China were collected, and lead and cadmium in 6 polluted areas by...  相似文献   
189.
采用合金膜电渗析法分离富集钽铌冶炼厂含氟废水中的F-和SO42-。最优的工艺运行条件为:膜对电压0.500 V,膜面流速4.09 cm/s。在此条件下电渗析30 min,F-去除率达97.53%,SO42-去除率接近100%。优化条件下运行电渗析器,一段淡水中大部分的F-和SO42-均被去除,可以直接回用。一段电渗析的浓水再经多段电渗析浓缩,以LiOH·H2O沉淀F-得到LiF产品,该LiF产品纯度达99.06%,满足GB/T 22666—2008标准的3级品要求。LiF收率为84.92%,F-整体回收率为79.45%。  相似文献   
190.
To tackle nonlinear economies-of-scale (EOS) effects in interval-parameter constraints for a representative waste management problem, an inexact piecewise-linearization-based fuzzy flexible programming (IPFP) model is developed. In IPFP, interval parameters for waste amounts and transportation/operation costs can be quantified; aspiration levels for net system costs, as well as tolerance intervals for both capacities of waste treatment facilities and waste generation rates can be reflected; and the nonlinear EOS effects transformed from objective function to constraints can be approximated. An interactive algorithm is proposed for solving the IPFP model, which in nature is an interval-parameter mixed-integer quadratically constrained programming model. To demonstrate the IPFP's advantages, two alternative models are developed to compare their performances. One is a conventional linear-regression-based inexact fuzzy programming model (IPFP2) and the other is an IPFP model with all right-hand-sides of fussy constraints being the corresponding interval numbers (IPFP3). The comparison results between IPFP and IPFP2 indicate that the optimized waste amounts would have the similar patterns in both models. However, when dealing with EOS effects in constraints, the IPFP2 may underestimate the net system costs while the IPFP can estimate the costs more accurately. The comparison results between IPFP and IPFP3 indicate that their solutions would be significantly different. The decreased system uncertainties in IPFP's solutions demonstrate its effectiveness for providing more satisfactory interval solutions than IPFP3. Following its first application to waste management, the IPFP can be potentially applied to other environmental problems under multiple complexities.  相似文献   
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