养殖场饲养鸡对苯并[a]芘的摄入、排泄和积累

在北京市郊区一家中等规模养鸡场采集了不同品种和不同生长阶段的饲养鸡的肌肉和内脏样品,并同步采集了鸡蛋、饲料、粪便和大气样品,测定了其中苯并[a]芘的浓度,据此分析了苯并[a]芘在饲养鸡体内的积累、排泄和代谢的动态过程.结果显示,饲养鸡体内各组织苯并[a]芘的湿重浓度在0.024～0.15ng·g-1之间,肌肉中的浓度显著低于其它组织;饲料和粪便中的浓度显著高于体内各组织浓度.饲养鸡体内摄入的苯并[a]芘约60%在体内代谢,约三分之一直接排泄进入粪便,仅有少量残留在体内如表皮、肌肉和其他器官中.肌肉、肝脏和胃中苯并[a]芘浓度和总累积量的动态变化规律不尽相同.北京居民摄食类似鸡肉导致的对苯并[a]芘的暴露量较春、秋、冬季呼吸暴露量低两个量级,与夏季呼吸暴露量相当.     

数值模拟技术在某爆燃事故致因分析中的应用

调查和分析火灾爆燃事故致因因素,明确事故发生原因,对做好事前预防、减少人员伤亡和财产损失等均具有重要作用和意义.通过计算机数值模拟技术,对一起火灾爆燃事故中的两个可能起火点火势蔓延情况进行再现,研究分析其燃烧速率、热释放速率、温度分布、速度矢量等参数和火势发展的动态模拟图像,并结合现场勘查、调查走访情况,进行相互对比认证,确定准确的起火点,最终找到导致爆燃事故发生的真正原因.     

Impact of work boots and load carriage on the gait of oil rig workers

Effects of work boots and load carriage (6.4?kg and 12.8?kg) on gait pattern were investigated. The protective work boots were examined by comparison with running shoes through human performance tests with 15 male participants. The loads were carried symmetrically and asymmetrically on the shoulder and hand. Statistical data analysis showed a prolonged stance phase and decreased double support for work boots. A significantly increased ground reaction force was found in work boot conditions as the weight of loads increases. This study demonstrates that inflexible and heavy work boots restrict foot movement and require greater torque at the ankle to propel the body forward, which may increase physical strain and the risk of musculoskeletal injuries. Development of improved fixation methods for work boots, increased use of flexible protective layers and further study of anthropometry of human foot morphology for improved safety and work efficiency of industry workers are suggested.     

从粉煤灰中提取多种微细氧化物的研究

将粉煤灰与Na2CO3按一定的比例混合后焙烧,采用酸碱联合法提取粉煤灰中氧化硅、氧化铝和氧化铁,分析了工艺条件对粉煤灰中氧化物提取率的影响。实验结果表明,从粉煤灰中提取氧化物的最佳条件是:碳酸钠与粉煤灰的比例0.6∶1.0,焙烧温度850℃、盐酸浓度4 mol/L,氢氧化钠浓度2.6 mol/L,浸取时间约6 h。在此条件下得出微细氧化硅、氧化铝、氧化铁的晶体,其平均粒度分别为氧化硅1.107μm,氧化铝1.334μm,氧化铁0.783μm。     

烟气脱硫剂制浆系统一体化设计及应用

石灰石粉制浆系统是石灰石-石膏湿法烟气脱硫工艺中脱硫剂浆液干式制备系统的一个主要部分。针对石灰石粉制浆系统传统设计的不足,提出了石灰石浆液罐与粉仓一体化设计的优化方案,具有节省投资、占地小、设计简单紧凑、系统可靠和寿命长的优点,尤其适合我国老小燃煤机组烟气脱硫改造工程。目前已成功应用于多个烟气脱硫工程。     

含聚采油废水外排达标处理技术

本文针对含聚合物采油废水中聚丙烯酰胺生物毒性大、生化降解困难,采用二级气浮+活性污泥工艺对高含聚采油废水进行了现场实验研究。实验结果表明,处理后外排水中COD 80 mg/L,降解效率96.9%;石油类2 mg/L,降解效率98.6%,外排水的各项指标均能达国家和地方的相关标准。     

离子膜制碱生产中电解槽氯气泄漏分析及对策

分析了离子膜制碱生产过程中电解槽氢气泄漏的原因,提出了应急处置方法和预防控制措施.     

浅析生态厕所在旅游业中的发展应用

鉴于水资源日益短缺,自然环境脆弱的实际情况,同时为了突破制约旅游业发展的"旅游厕所"这一瓶颈,坚持使用高科技、节能环保的生态厕所技术,以确保旅游业持续、快速、健康的发展.由于并非每一种生态环保厕所技术都适用于旅游业.文章从对现有的生态厕所进行技术归类、分析、总结,提出了适应于旅游业发展的生态厕所技术类型以及适用场所,并进一步指出现有生态厕所在应用中存在的一些技术问题.     

鞍山市环境空气中PM10、PM2.5污染特征研究

文章对鞍山市环境空气中细颗粒物（PM2.5）、可吸入颗粒物（PM10）季节性变化及月变化污染特征进行分析,不同季节的PM2.5、PM10变化趋势均为夏季〈秋季〈春季〈冬季;PM2.5、PM10的月均质量浓度按高低顺序分别为：12月〉1月〉11月〉2月〉10月〉4月〉3月〉7月〉8月〉6月〉5月〉9月和1月〉12月〉3月〉4月〉2月〉10月〉11月〉5月〉6月〉7月〉8月〉9月。同时,分析了ρ（PM2.5）对ρ（PM10）的贡献率,全年的ρ（PM2.5）/ρ（PM10）平均值为57.8%,结果表明,在PM10中,PM2.5的含量要大于PM2.5-10的含量。     

Degradation of chlorinated phenols by nanoscale zero-valent iron

Chlorophenols (CPs), as important contaminants in groundwater, are toxic and difficult to biodegrade. Recently nanoscale zero-valent iron received a great deal of attention because of its excellent performance in treating recalcitrant compounds. In this study, nanoscale zero-valent iron particles were prepared using chemical reduction, and the reductive transformations of three kinds of chlorinated phenols (2-CP, 3-CP, and 4-CP) by nanoscale zero-valent iron under different conditions were investigated. The transformation process of the CPs was shown to be dechlorination first, then cleavage of the benzene ring. The removal efficiency of the CPs varied as follows: 2-CP > 3-CP > 4-CP. The reactivity of CPs was associated with their energy of lowest unoccupied molecular orbit (E _LUMO). With the increase in initial concentrations of CPs, removal efficiency decreased a little. But the quantities of CPs reduced increased evidently. Temperature had influence on not only the removal efficiency, but also the transformation pathway. At higher temperatures, dechlorination occurred prior to benzene ring cleavage. At lower temperatures, however, the oxidation product was formed more easily. __________ Translated from China Environmental Science, 2006, 26(6): 698–702 [译自: 中国环境科学]