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The emission of the dioxin-like compounds from on-site waste incinerators of seven schools in Kyonggi Province of Korea was evaluated by determination of the cytochrome P4501A(CYP1A) catalytic activity and antiestrogenic activity using cell culturemicrobioassay. The residue samples were extracted in a Soxhlet apparatus using toluene for 20 hr. The concentrated crude extractswere fractionated with a basic alumina column. Dioxin-like compounds were then extracted. Induction of CYP1A activity in a rat(H4IIE) hepatoma cell line was used as indicator of biologicaleffect of incinerator residues and measured as 7-ethoxyresorufin-O-deethylase(EROD) activities. The EROD activities of fraction II extracts (one of the two extracts) in the H4IIE cells were from 0.044±0.002 to 4.424±0.351 ng-TEQ g-1 (TCDD Toxicity equivalent), showing relatively high inducing capacity. Antisetrogenicity of the extracts was measured as decrease in E2-induced cell proliferation. Most of the extracts showed antiestrogenic activity in MCF7-BUS cell.The TEQ levels of the incinerator residues and the antiestrogenicactivities were in good correlation, strongly suggesting that thepotent toxic emissions were indeed produced from the on-site school waste semi-incinerators and could cause the antiestrogenicity. 相似文献
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介绍了环境保护中专办学20年来所取得的成绩及其为环保事业的发展做出的积极贡献,并指出存在的问题.为适应环保事业发展的需要,对环保中专在专业设置、课程设置、教学计划和教材建设方面,均提出改革意见 相似文献
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根据钢筋混凝土多层框架的设计经验和设计规范,对如何调整电算结果中的梁,柱截面尺寸,配筋率,裂缝宽度和梁,柱配筋等问题进行探讨,并提出相应的建议。 相似文献
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Krista Harper Catherine Sands Diego Angarita Horowitz Molly Totman Monica Maitín Jonell Sostre Rosado 《Local Environment》2017,22(7):791-808
How do youth learn through participation in efforts to study and change the school food system? Through our participatory youth action research (YPAR) project, we move beyond the “youth as consumer” frame to a food justice youth development (FJYD) approach. We track how a group of youth learned about food and the public policy process through their efforts to transform their own school food systems by conducting a participatory evaluation of farm-to-school efforts in collaboration with university and community partners. We used the Photovoice research method, placing cameras in the hands of young people so that they themselves could document and discuss their concerns and perspectives. The research was designed to gain insight about youths’ knowledge of food, health, and community food systems. Drawing upon the youth group’s insights, we build a framework for building critical consciousness through FJYD. 相似文献
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为了规范绿色学校创建程序、申报和验收工作,通过对绿色学校创建过程中存在问题的研究,阐述了绿色学校创建过程中针对创建程序、验收形式、申报材料要求等三方面的看法和观点。 相似文献
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为研究小学教学楼楼梯间人员运动行为以及影响人员疏散的因素,开展人员疏散实验并构建疏散模拟场景。基于疏散实验研究不同实验场景的出口流量和人员运动速度,通过疏散仿真模拟,分析不同人员运动速度、人员数量及疏散策略对疏散的影响。结果表明:排队下楼的人员运动速度比紧急疏散人员低22.7%,自由上楼人员运动速度比排队上楼人员高8%;人员总疏散时间随人员运动速度的增加而降低,但总疏散时间随速度增加而降低的幅度变小;加入分层疏散策略会增加人群疏散总时间,但整个疏散过程人员分布均匀,在建筑瓶颈不易产生人员过度拥挤现象,因而在疏散过程中应适当采用分层疏散策略。 相似文献
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Point Sampling Digital Imagery with ‘Samplepoint’ 总被引:1,自引:0,他引:1
Measuring percent occurrence of objects from digital images can save time and expense relative to conventional field measurements. However, the accuracy of image analysis had, until now, not reached the level of the best conventional field measurements. Additionally, most image-analysis software programs require advanced user training to successfully analyze images. Here we present a new software program, ‘SamplePoint,’ that provides the user a single-pixel sample point and the ability to view and identify the pixel context. We found SamplePoint to allow accuracy comparable with the most accurate field-methods for ground-cover measurements. Expert use of the program requires minimal training and its ease of use allows rapid measurements from image data. We recommend SamplePoint for calibrating the threshold-detection level of image-analysis software or for making direct measurements of percent occurrence from digital images. 相似文献
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端部约束不同的构件在火灾中的破坏形态不同,研究整体结构构件在火灾中的破坏形态,可以为钢结构抗火研究与设计提供依据。某钢结构框架厂房发生火灾,大火历时3个多小时,火场最高温度达1000°C以上。火灾后,框架梁均有不同程度的破坏,钢梁端部下翼缘屈曲破坏较普遍;由于钢梁顶没有设置抗剪键,钢梁与顶部的混凝土现浇楼板脱开,火灾后残留有较大的挠屈变形;钢柱在火灾后未有明显的破坏现象,但有侧向变形产生。这些现象与实验室中标准试验的结果不同。 相似文献