PAH专用柱和C18柱对PAH混合溶液分析中的对比

运用多环芳烃专用柱HX736091(4.6×250mm、5μm),对16种多环芳烃化合物混合溶液进行分析,与常用的C18柱(ZORBAX SB-C18、4.6×250mm、5μm)进行比较,结果显示多环芳烃专用柱对该16种多环芳烃化合物的分离效率远远高于C18柱。     

新修《安全生产法》对生产经营单位安全生产保障义务的新要求

为探究新修《安全生产法》在生产经营单位安全生产保障义务方面的新变化,本文从安全生产主体责任方面暴露的突出问题入手,对新修《安全生产法》中生产经营单位安全生产保障义务提出的保障义务内容、主要变化、不履行保障义务的法律风险进行详细分析,结果显示,变化主要体现在:安全保障义务从生产安全向公共安全拓展;从个别(局部)责任向全员责任拓展;从人的行为向人的心理拓展.对于不履行义务处罚力度加重、联合惩戒风险增加还可能承担刑事制裁风险.并针对这些变化提出生产经营单位贯彻落实好《安全生产法》的建议.     

对几种公路交通噪声预测模式的差异分析

文章从评价范围、源强界定和参数修正三方面对《环境影响评价技术导则声环境》(HJ/T 2.4-1995)、《环境影响评价技术导则声环境》(HJ 2.4-2009)、《公路建设项目环境影响评价规范(试行)》(JTJ 005-96)、《公路建设项目环境影响评价规范》(JTGB 03-2006)、《环境影响评价技术导则公路建设项目》(HJ 552-2010)等五种公路交通噪声预测模式的差异进行对比分析,探究哪种预测模式更加合理。     

基于中美10所高校的应急管理核心知识体系的解释结构模型研究

应急管理涉及多学科、多领域,明确其核心知识体系可以为应急管理相关学科融合和发展提供基础。本文收集了中美两国10所高校15个本科专业225门专业课程,构建解释结构模型进行研究。结果显示：应急管理核心知识体系包括8大类：应急类、防灾减灾类、公共服务和社会管理类、安全生产类、国家安全类、法律类、公共卫生类和综合类。这8大类又分为18个小类,应急类包括为理论、技术方法和应用;防灾减灾类包括理论、过程和单灾种防范;公共服务和社会管理类包括理论与应用;安全生产类包括安全、健康和环境;国家安全类包括国土安全、恐怖主义和国际关系;公共卫生类包括心理和医疗救助;而法律类重在应急相关法律,综合类则表现为多个领域相结合。该体系的构建可以为应急管理相关学科研究提供知识基础,促进各学科领域在应急研究方面融合发展。     

石英E1′心电子自旋共振信号强度的热活化研究

石英E₁′心是一种重要的顺磁性缺陷,其热活化ESR信号强度的最大值有许多新的应用,但对于获取E₁′心信号强度最大值的方法尚存不同的认识。为了进一步研究和探讨石英E₁′心信号的增强机理及石英E₁′心ESR信号强度最大值的获取方法,采用电子自旋共振（ESR）技术测量了两个冰碛物样品在300℃等温加热前和加热后石英E₁′心的ESR信号强度,结果表明：在室温下,石英E₁′心信号强度随辐照剂量的增加而增强是由于伪E₁′心的形成而造成的;而石英E₁′心信号强度随辐照剂量增加而减弱可能是因为辐照使已增强的E₁′心产生衰退。300℃的等温热退火实验（分为15 min和20 min）结果表明：获取E₁′心ESR信号强度的最大值需要人工辐照,人工辐照的作用不仅是提供更多的空穴,而且可能更有利于氧空位向E₁′心转化。     

Combination system of full-scale constructed wetlands and wetland paddy fields to remove nitrogen and phosphorus from rural unregulated non-point sources

Constructed wetlands (CWs) have been used effectively to remove nitrogen (N) and phosphorus (P) from non-point sources. Effluents of some CWs were, however, still with high N and P concentrations and remained to be pollution sources. Widely distributed paddy fields can be exploited to alleviate this concern. We were the first to investigate a combination system of three-level CWs with wetland paddy fields in a full scale to remove N and P from rural unregulated non-point sources. The removal efficiencies (REs) of CWs reached 57.3 % (37.4–75.1 %) for N and 76.3 % (62.0–98.4 %) for P. The CWs retained about 1,278 kg N ha^?1 year^?1 and 121 kg P ha^?1 year^?1. There was a notable seasonal change in REs of N and P, and the REs were different in different processing components of CWs. The removal rates of wetland paddy fields adopt “zero-drainage” water management according to local rainfall forecast and physiological water demand of crop growth reached 93.2 kg N ha^?1 year^?1 and 5.4 kg P ha^?1 year^?1. The rice season had higher potential in removing N and P than that in the wheat season. The whole combined system (0.56 ha CWs and 5.5 ha wetland paddy fields) removed 1,790 kg N year^?1 and 151 kg P year^?1, which were higher than those from CWs functioned alone. However, another 4.7-ha paddy fields were needed to fully remove the N and P in the effluents of CWs. The combination of CWs and paddy fields proved to be a more efficient nutrient removal system.     

Macrozoobenthic assemblages in relation to environments of the Yangtze-isolated lakes

Eutrophication can shift lakes from a clear, macrophyte-dominated state to a turbid, algae-dominated state, and different habitat condition supports different fauna. Macrozoobenthos are good indicators of water environment, and studies on macrozoobenthic assemblage characteristics can help us to know which state a lake is in, thus provide the basis for its eutrophication control. In this study, a systematic investigation on macrozoobenthos was conducted in 17 Yangtze-isolated lakes to explore the macroecological laws of macrozoobenthic assemblages. Detrended correspondence analysis (DCA) revealed that variance of benthic assemblage structure occurred in two types of lakes. In macrophytic lakes, altogether 51 taxa of macrozoobenthos were identified. The average density and biomass of total macrozoobenthos were 2231 individuals·m^?2 and 1.69 g dry weight·m^?2, respectively. Macrozoobenthic assemblage was characterized by dominance of scrapers (i.e. gastropods). In algal lakes, altogether 20 taxa of macrozoobenthos were identified. The average density and biomass of total macrozoobenthos were 2814 individuals·m^?2 and 1.38 g dry weight·m^?2, respectively. Macrozoobenthic assemblage was characterized by dominance of collector-gatherers (i.e. oligochaetes). Wet biomass of submersed macrophytes (B _Mac) and phytoplankton chlorophyll a concentration (Chl a) were demonstrated as the key factor structuring macrozoobenthic assemblages in macrophytic and algal lakes, respectively.     

半挥发性有机污染物的气相色谱纯化方法

以六氯苯作为模型化合物,建立了半挥发性有机污染物样品净化的气相色谱方法.采用进样阀切换载气吹扫的进样方式,通过保留间隙柱和溶剂放空装置实现大体积进样,经过气相色谱分离后将分析物所在的半挥发性组分选择性冷凝在收集管中.本方法对模型化合物六氯苯的制备回收率为90%,对半挥发性有机污染物样品净化方法的发展具有重要意义.     

雾霾期北京大气中多环芳烃污染特征及暴露风险评估

雾霾对我国尤其是华北平原地区造成了极大的困扰,其发生常以颗粒物浓度急剧增长为特征,给人群健康带来了极大的风险。为进一步阐释雾霾的形成过程及其健康效应,在冬季雾霾期对北京城区大气颗粒态及气态中18种多环芳烃(PAHs)进行了连续测定,同步监测颗粒物、痕量气体污染物以及气象参数的变化,并对PAHs的浓度、组成、气粒分配等大气行为以及其与气象因素的作用机制进行了探讨。北京城区大气气相和颗粒物相中ΣPAHs浓度分别为585 ng·m~(-3)和705 ng·m~(-3)。雾霾发生时,PM_(2.5)浓度升高了3.6倍,PAHs浓度升高了2.6倍,18种PAHs同系物的浓度均随PM_(2.5)的浓度线性增加,其线性相关性受PAHs来源以及氧化活性的影响;夜间较重质量数的PAHs相对比例增加,主要受日间交通源以及夜间燃烧源贡献强度影响。受颗粒物组成以及湿度的影响,雾霾天气下PAHs颗粒相分配率降低。进一步评估了北京城区人群的PAHs吸入健康效应,冬季雾霾频繁发生下其对人群癌症风险为6.2×10~(-5)。     

短、中、长链氯化石蜡暴露对细胞代谢影响的比较研究

氯化石蜡(chlorinated paraffins, CPs)在中国大量生产和使用,导致其在环境介质中的含量较高。采用拟靶向代谢组学技术,比较研究了短、中和长链氯化石蜡在人体内暴露水平下(100μg·L~(-1))对HepG2细胞代谢的影响。结果表明,短、中和长链氯化石蜡暴露引起了HepG2细胞增殖活力的降低与代谢活动的显著变化。短链氯化石蜡(SCCPs)暴露对细胞代谢的影响强度略高于中链氯化石蜡(MCCPs)和长链氯化石蜡(LCCPs)。3种氯化石蜡均显著扰乱了脂质代谢,且影响程度相近。显著受影响的代谢通路包括:甘油磷脂代谢、亚油酸代谢、α-亚麻酸代谢、花生四烯酸代谢和鞘磷脂代谢。同时,3种氯化石蜡暴露也显著扰乱了甘氨酸、丝氨酸和苏氨酸代谢,缬氨酸、亮氨酸和异亮氨酸生物合成,牛磺酸和亚牛磺酸代谢;此外,LCCPs还扰乱了苯丙氨酸、酪氨酸和色氨酸生物合成通路。相比于SCCPs和MCCPs,LCCPs对氨基酸代谢表现出更强的干扰效应。