石油加工过程的环境影响后评价

我国的石油加工过程环境影响评价工作属于前期预测评价,存在一定的局限性。目前,石油加工过程的环境影响后评价工作尚处于探索发展阶段。本文主要介绍了石油加工过程及其环境影响后评价的概念,分析了石油加工过程的主要环境影响,详述了石油加工过程环境影响后评价的程序、内容及评价指标,并结合实例加以说明。最后指出,开展石油加工过程的环境影响后评价工作势在必行。     

Effect of processing on the disappearance of pesticide residues in fresh-cut lettuce: Bioavailability and dietary risk

The aim of this research is to establish the processing factors of six pesticides durong the preparation of fresh-cut lettuce and to assess the risk of ingestion of pesticide residues associated with the consumption of the same. A field study was carried out on the dissipation of three insecticides (imidacloprid, tebufenozide, cypermethrin) and three fungicides (metalaxyl, tebuconazole, azoxystrobin) during treatment conditions simulating those used for commercial fresh-cut lettuce. A simultaneous residue analysis method is validated using QuEChERS extraction with acetonitrile and CG-MS and LC-MS/MS analysis. The residues detected after field application never exceed the established Maximum Residue Limits. The processing factors were generally less than 1 (between 0.34 for tebufenozide and 0.53 for imidacloprid), indicating that the process, as a whole, considerably reduces residue levels in processed lettuce compared to fresh lettuce. It is confirmed that cutting, followed by washing and drying, considerably reduces the residues. A matrix effect in the dialyzation of the pesticides is observed and the in vitro study of bioavailability establishes a low percentage of stomach absorption capacity (<15%). The EDI/ADI ratios found in all cases were well below their ADI values, and the dietary exposure assessed (EDI) in fresh-cut lettuce showed no concerns for consumer health.     

基于农校对接的高校食品安全管理研究

从高校食品工作的特点出发,总结了高校食品安全的特点,提出了＂农校对接＂的解决途径,并分析了开展农校对接的意义,从高校食品安全管理者、食品供应者、物流等角度阐述了开展农校对接的具体措施。     

废水中KMnO4对生物处理效果的影响

为减轻和消除含高浓度KMnO4的牛仔服加工废水对生物处理系统的毒害作用,采用模拟序批式活性污泥法,研究KMnO4对活性污泥微生物生长的影响及COD和NH4+-N的降解规律。结果表明,当处理进水COD浓度500 mg/L,NH4+-N浓度23.5 mg/L,污泥浓度为2 000 mg/L时,曝气时间为4 h,KMnO4质量浓度增加对COD和NH4+-N的降解影响很大;同样条件下曝气时间改为8 h,对NH4+-N的降解影响显著减小,但对COD的降解影响减少不多;并且,高浓度KMnO4对NH4+-N去除效果的抑制作用比对COD的大。因此,处理含高浓度KMnO4的废水需要延长一倍曝气时间,可以获得良好的COD和NH4+-N的降解效果。同时,KMnO4对活性污泥的抑制影响较好地吻合非竞争性抑制机理修正莫若特方程的规律。     

Neighborhood satisfaction,physical and perceived naturalness and openness

This study examined neighborhood satisfaction in relation to naturalness and openness. It used Geographic Information System (GIS) and Landsat satellite imagery to physically measure the environmental attributes. Through path analysis it examined the relationship among the attributes, resident ratings of those environmental attributes, their satisfaction with them, and their overall neighborhood satisfaction (n = 725). We expected overall neighborhood satisfaction to relate to the resident's ratings of the environmental attributes and to the physical measures of them. The path model showed that overall neighborhood satisfaction was associated directly with the physical measure of building density and indirectly with the physical measure of vegetation rate through perception and evaluation of them. The perceptions and evaluations of the attributes related to one another. With refinements, GIS and Landsat data geo-related to survey data can offer a powerful tool for understanding the complex nature of neighborhood satisfaction and behavior.     

煤矿砂岩动态力学性能试验与分析方法研究

为研究动载荷作用下煤岩体测试与分析方法,基于直径50 mm分离式Hopkinson试验装置,采用半导体应变片和电阻应变片2种方法采集透射波,开展淮北矿区典型砂岩动态冲击压缩试验,采用二波法和三波法分别计算得到砂岩试件的应变率、应力和应变峰值等动态力学参数以及能量耗散特征,分析不同应变片种类和计算分析方法的差异性.结果表...     

基于人工神经网络的火灾图象探测方法

提出了一种新型的火灾探测方法,基于ＢＰ神经网络的火灾图象探测方法。该方法利用了早期火灾火焰的形体变化特性,用图象处理的方法提取特征信息,最后利用人工神经网络来进行火灾判,别。     

中国火灾探测技术的现状及其发展趋势

对我国火灾探测技术进行讨论。随着社会的进步,建筑物结构的复杂化程度越来越高。对于高可靠性、智能化、快速响应的新型火灾探测技术的研究是火灾探测领域的研究热点和发展趋势。     

数理统计在环境放射性数据处理中的运用

环境中的放射性数据处理是一项重要的基础工作,在辐射环境常规监测中放射性数据运用科学的方法进行处理,避免数据处理工作中的主观性、随意性。本文例举说明如何运用数理统计的方法进行放射性数据的分析评判。