逆转录-聚合酶链反应(RT-PCR)技术同时检测水中多种肠道病毒

建立了一种利用通用引物RT-PCR技术检测水中肠道病毒的方法.利用脊髓灰质炎病毒1～3型,柯萨奇病毒B3型作为参考病毒株,根据肠道病毒RNA5′非编码区中具有高度同源性的序列来设计通用引物.比较了M-MLV酶和AMV酶的逆转录效果,AMV酶能够成功地从地表水和生活污水中逆转录病毒RNA,更适于实际应用.对比研究了PCR过程中的退火温度,c(Mg2＋)等因素对RT-PCR检测结果的影响,选择退火温度55　℃,c(Mg2＋)为2　mmol/L的反应条件,优化了RT-PCR检测方法.通过检测水样中接种的连续稀释的病毒,确定了该检测方法的灵敏度为38　CCID₅₀.考察人工污染的地表水、污水、二级处理出水样品发现,检测灵敏度基本一致.该方法可应用在实际环境的肠道病毒检测中.      

丙酸的加入对厌氧-低氧同时生物除磷脱氮系统的影响

2个实验室规模的序批式反应器（SBRs）在厌氧-低氧（0.15～0.45 mg·L^-1）条件下运行,以比较丙酸的加入对同时生物除磷脱氮系统的影响.结果表明,无论是丙酸与乙酸的混合酸（碳摩尔比为1.5/1）作为碳源（SBR1）,还是乙酸作为单独碳源（SBR2）,系统都发生同步硝化反硝化和磷的去除（SNDPR）,并且氨氮被全部氧化,系统中没有亚硝酸盐的大量累积.与SBR2相比,SBR1中厌氧阶段磷释放量少,聚羟基戊酸（PHV）合成量高,好氧末磷剩余量少,硝态氮累积少,因此SBR1中总氮和总磷的去除率（分别为68%和95%）比SBR2（分别为51%和92%）高,加入丙酸有助于SNDPR系统保持较好的除磷、脱氮效果.     

颗粒污泥SBR处理生活污水同步除磷脱氮的研究

采用厌氧-好氧的SBR运行方式,以人工配水培养的好氧颗粒污泥为接种污泥,处理碳、氮、SS浓度均较高的生活污水,研究了系统中颗粒污泥的稳定性及其去除有机物和同步除磷脱氮的效果.经过1个月的驯化培养,颗粒污泥即可呈现出良好的污染物去除性能并趋于稳定,反应器中颗粒污泥含量始终占污泥总量的68%以上.颗粒污泥系统污泥浓度为5 000～6000mg/L,SVI值为20～35 mL/g.经过3个月的运行后,反应器中颗粒污泥由原来以粒径0.6～0.9 mm的中等大小颗粒占主体变为粒径＞1.25 mm的大颗粒占主体.稳定运行阶段颗粒污泥系统对COD、TOC、磷酸盐、氨氮、总氮和SS的平均去除率分别为83.04%、70.41%、94.30%、86.51%、41.82%和85.89%.对反应器运行过程中典型周期的分析,反映出颗粒污泥良好的同步除磷脱氮效果.     

同步硝化反硝化技术研究进展

结合国内外最新研究成果,从微环境理论、生物学理论对同步硝化反硝化的产生机理进行了介绍,阐述了同步硝化反硝化技术的影响因素及其研究进展,介绍了同步硝化反硝化技术的最新应用情况,对该技术需要解决的问题及应用前景作了探讨.     

基于结构方程模型的环境风险接受度影响因素分析

随着社会经济的发展和城市化进程的推进,我国环境风险事故频发。与此同时,公众对于美好环境的需求日益提升,公众与专家和政府之间的风险判断差异是不同规模的群体性事件发生的主要诱因。为识别公众环境风险接受度的影响因素,本研究基于结构方程模型分析了11种环境风险的客观风险水平和公众感知到的风险影响度、场域了解度、政府信任度、社会经济水平等因素对公众风险接受度的影响。研究结果显示,社会经济水平、风险影响度、场域了解度、政府信任度均直接影响公众的风险接受度;客观风险水平则通过风险影响度的中介作用间接影响风险接受度。因此,为在经济发展过程中降低公众风险感知偏差对生产生活的影响,我国除了通过更严格的风险管控手段降低风险事故发生概率和影响范围外,还需要通过信息公开、公众参与和生态科普等方式增强公众对风险场域的了解度和对政府的信任度以提升风险接受能力。     

智能手机应用程序使用与操作的驾驶分心风险影响研究

为研究智能手机应用程序操作方式与使用行为对驾驶分心影响的问题,探讨智能手机程序操作方式对驾驶分心影响的优劣关系,基于结构方程模型提出4个因果关系假设,构建涵盖程序使用、驾驶分心、驾驶绩效等潜变量的智能手机使用行为影响的结构方程模型。通过收集线下问卷的方式进行调查,搭建模拟场景,设计6项实验方案,通过驾驶模拟实验方式收集相关数据,建立相对偏差矩阵。研究结果表明：手机通话功能的使用(路径系数0.472)对驾驶分心影响显著,手机导航功能使用(路径系数0.256)、手机音乐功能使用(路径系数0.249)对驾驶分心影响不显著。语音交互方式均优于手动操作方式,其中语音交互启动导航方式(F₃=0.019)的影响最小。研究结果可对道路驾驶情况下智能手机应用使用与操作方式的研究起推动作用。     

An application of a modified theory of planned behavior model to investigate adolescents’ job safety knowledge,norms, attitude and intention to enact workplace safety and health skills

Introduction: For many reasons, including a lack of adequate safety training and education, U.S. adolescents experience a higher rate of job-related injury compared to adult workers. Widely used social-psychological theories in public health research and practice, such as the theory of planned behavior, may provide guidance for developing and evaluating school-based interventions to prepare adolescents for workplace hazards and risks. Method: Using a structural equation modeling approach, the current study explores whether a modified theory of planned behavior model provides insight on 1,748 eighth graders’ occupational safety and health (OSH) attitude, subjective norm, self-efficacy and behavioral intention, before and after receiving instruction on a free, national young worker safety and health curriculum. Reliability estimates for the measures were produced and direct and indirect associations between knowledge and other model constructs assessed. Results: Overall, the findings align with the theory of planned behavior. The structural equation model adequately fit the data; most path coefficients are statistically significant and knowledge has indirect effects on behavioral intention. Confirmatory factor analyses suggest that the knowledge, attitude, self-efficacy, and behavioral intention measures each reflect a unique dimension (reliability estimates ≥0.86), while the subjective norm measure did not perform adequately. Conclusion: The findings presented provide support for using behavioral theory (specifically a modified theory of planned behavior) to investigate adolescents’ knowledge, perceptions, and behavioral intention to engage in safe and healthful activities at work, an understanding of which may contribute to reducing the downstream burden of injury on this vulnerable population—the future workforce. Practical application: Health behavior theories, commonly used in the social and behavioral sciences, have utility and provide guidance for developing and evaluating OSH interventions, including those aimed at preventing injuries and promoting the health and safety of adolescent workers in the U.S., who are injured at higher rates than are adults.     

社会资本对山区居民山洪灾害应急避险能力的影响研究*

为研究社会资本对山区居民应急避险能力的影响,在广泛调研的基础上采用结构方程模型分析社会资本与山区居民应急避险能力各要素之间的作用关系。结果表明:个人网络对避险知识和避险意识有显著的正向影响,对避险行为影响不显著;信任与避险知识和避险意识呈显著的正向影响,而与避险行为呈反向影响,但信任可以通过避险知识和避险意识间接正向影响避险行为;互惠对避险知识影响不显著,但互惠与避险意识和避险行为存在显著的正向关系;避险知识和避险意识对避险行为呈显著正向影响,其中避险意识对避险行为影响更为显著。因此可以通过增加山区居民社会资本的方式提高山区居民山洪灾害应急避险能力。     

农地整治权属调整中农户认知对行为响应的作用机制--基于改进TPB及多群组SEM

农地整治权属调整是实现农业规模化和现代化的重要手段,而农户有效参与是推动权属调整的内在动力,研究农地整治权属调整中农户认知对其行为响应的作用机制,有助于高效引导农户参与权属调整,并为制定农地整治权属调整的政策提供科学依据。基于改进计划行为理论和湖北省11个县(市、区)1044份农户抽样调查数据,采用多群组结构方程模型探究了农地整治权属调整中不同类型农户认知对其行为响应的作用机制。结果表明:农地整治权属调整中农户行为逻辑符合改进计划行为理论,农户的行为态度、主观规范、知觉行为控制交互影响行为意愿,进而转换为行为响应,政府支持在行为意愿和行为响应之间起到部分中介作用。总体上,农户行为响应是"自发性""诱发性"和"约束性"三重行动逻辑的结合,且"自发性"占主导地位。多群组结构方程估计结果表明,纯农型与兼业Ⅰ型农户的行为响应受到"自发性""诱发性"和"约束性"三重影响,兼业Ⅱ型农户受到"自发性"和"诱发性"双重影响,非农型农户仅受到"诱发性"单一影响。因此,为引导农户积极参与农地整治权属调整,应该分别针对各类农户相应地提高其参与的"自发性"和"诱发性",降低"约束性",充分发挥农村社会经济组织的作用,将四种不同类型农户的利益需求统筹考虑,降低权属调整过程中利益协调难度。     

Structural equation model analysis for the evaluation of overall driving performance: A driving simulator study focusing on driver distraction

Objective: The present research relies on 2 main objectives. The first is to investigate whether latent model analysis through a structural equation model can be implemented on driving simulator data in order to define an unobserved driving performance variable. Subsequently, the second objective is to investigate and quantify the effect of several risk factors including distraction sources, driver characteristics, and road and traffic environment on the overall driving performance and not in independent driving performance measures.

Methods: For the scope of the present research, 95 participants from all age groups were asked to drive under different types of distraction (conversation with passenger, cell phone use) in urban and rural road environments with low and high traffic volume in a driving simulator experiment. Then, in the framework of the statistical analysis, a correlation table is presented investigating any of a broad class of statistical relationships between driving simulator measures and a structural equation model is developed in which overall driving performance is estimated as a latent variable based on several individual driving simulator measures.

Results: Results confirm the suitability of the structural equation model and indicate that the selection of the specific performance measures that define overall performance should be guided by a rule of representativeness between the selected variables. Moreover, results indicate that conversation with the passenger was not found to have a statistically significant effect, indicating that drivers do not change their performance while conversing with a passenger compared to undistracted driving. On the other hand, results support the hypothesis that cell phone use has a negative effect on driving performance. Furthermore, regarding driver characteristics, age, gender, and experience all have a significant effect on driving performance, indicating that driver-related characteristics play the most crucial role in overall driving performance.

Conclusions: The findings of this study allow a new approach to the investigation of driving behavior in driving simulator experiments and in general. By the successful implementation of the structural equation model, driving behavior can be assessed in terms of overall performance and not through individual performance measures, which allows an important scientific step forward from piecemeal analyses to a sound combined analysis of the interrelationship between several risk factors and overall driving performance.