木工机械引发事故原因与预防措施

介绍木制品加工过程中的危险、有害因素，分析木工机械引发事故的原因，提出一些预防事故发生的措施．     

自然环境因素对铝合金大气腐蚀的影响性研究

目的 研究铝合金大气腐蚀受自然环境因素的影响性，探索环境因素对铝合金腐蚀的影响规律。方法 采用多层感知器神经网络分析环境因素对7种铝合金平均腐蚀速率的影响。结果 确定了影响铝合金腐蚀损伤的重要因素为SO2沉积率、Cl^–沉积率、NOx沉积率；辅要因素为年降雨量、年雾露时数、相对湿度、年日照时数、温度、铝合金成分；次要因素为年累积降水时数、雨水pH值。结论 基于多层感知器神经网络分析有效展现了环境因素对平均腐蚀速率的影响性。     

序批式膜生物反应器处理猪场沼液中氮的影响因素研究

猪场沼液具有高氨氮、低碳氮比(C/N)和脱氮难度大等特点,实验采用序批式膜生物反应器进行处理。结果表明,为达到较好的脱氮效果,进水COD宜控制在800~1 000mg/L;NH3-N为800mg/L时不会抑制硝化反应,C/N越高脱氮效果越好,C/N从8下降到1时,TN去除率由82.2%下降为16.7%;pH为8.5时脱氮效果最佳;夏天(进水水温25℃)脱氮效果优于冬天(进水水温13℃),TN去除率分别为93.13%、81.31%,进水水温在10~30℃时,进水水温越高脱氮效果越好。     

Triclosan in Fresh Water Fish Gibelion Catla from the Kaveri River,India, and Its Consumption Risk Assessment

Triclosan is a common antimicrobial agent that is found in significant levels in the aquatic environment and may elicit effects on aquatic organisms through unexpected modes of action. In this study, triclosan was quantified in fish from the Kaveri River, India, by using the gas chromatography and mass spectrometry technique and it was found in the range of 0.73–50 ng/g wet weight (ww). The mean bioaccumulation factor based on water (BAF_w 820) and sediment (BAF_s 2.12) in the Kaveri River showed that triclosan is accumulative in fish, and reflects its feeding behavior. The bioaccumulation indicates triclosan's persistence or prevalence throughout the river stretch. Human risk assessment through dietary intake demonstrated that the triclosan exposure is five orders of magnitude lower than the acceptable daily intake (50 μg/kg bw) and US EPA reference dose (300 μg/kg bw/day). This investigation is the first to report the bioaccumulation of triclosan in freshwater fish from India. Further, the results indicate that this fish acts as a biomarker of exposure for triclosan and thus shall be used to report triclosan pollution in the future.     

钢筋混凝土矩形梁在实际火灾下正截面承载力数值计算

为了正确评估钢筋混凝土矩形梁在实际火灾条件下的承载力,以一般室内火灾轰燃后的房间平均温度-时间曲线为火作用,以建筑结构耐火理论为基础,采用数值计算方法研究钢筋混凝土矩形梁的正截面承载力.研究结果表明:梁的承载力随火灾房间温度升高而变小,在温度达到最大值后承载力达到最小值.火灾房间火灾荷载越大,开口因子越小,火作用越大,梁的最小承载力越小;反之相反.相同条件下梁支座截面的承载力要大于跨中截面.     

液化天然气泄漏扩散实验的CFD模拟验证

运用CFD软件fluent对LNG泄漏扩散的Burro实验进行了模拟,并将不同点处模拟的温度和浓度随时间的变化与实验结果进行了对比.结果表明,温度和浓度的变化趋势与实验值基本一致,水平面、侧面以及对称面上的浓度等值线分布也与实验基本吻合,模拟得到的下风向处甲烷的最大体积分数在近源处要低于实验值,在距离泄漏源较远处则偏高,最后在实验结果的基础上,计算了模拟结果的统计误差,并将其与各种模型的误差进行对比,结果表明fluent的误差要低于其他模型,所预测的值总体上来说偏高.     

浅谈水质中总氮测定的影响因素

从地表水总氮测定中需要注意的要素入手,就实验室用水、试剂影响、器皿影响、操作过程、消解温度、消解时间以及消解冷却时间和实验环境条件的控制等方面的要求进行了简要论述,以化繁为简的思路指导今后的总氮测定工作。     

新安江水库主要入流营养盐的时间变化特征及其影响因素分析

流域上游来水是水库的重要补给源，其水质状况直接决定下游受纳水库的生态系统状态和功能，研究入库来水营养盐的时间演变特征并揭示其变化的影响因素，为水库水质管理提供重要科学依据。以新安江水库安徽辖区为研究区，分析了2007—2016年期间流域入库水质的变化特征，探讨水文、气象等环境条件对入库水质的影响。研究结果表明，2007年以来，COD_Mn和透明度表现为下降趋势，TN、TP、NH₃-N呈明显上升趋势，来水营养水平上升，但叶绿素a呈下降趋势。流域降水带来的水文情势的变化对来水水质起重要作用，来水中N、P营养盐丰水期显著高于枯水期，同流域降水过程显著正相关。     

Fatally injured drivers in Norway 2005–2015—Trends in substance use and crash characteristics

Objective: Norway introduced a “Vision Zero” strategy in 2001, using multiple approaches, aiming toward a future in which no one will be killed or seriously injured in road traffic crashes (RTCs). Official statistics show that the number of fatally injured road users has declined substantially from 341 deaths in 2000 to 117 in 2015. In-depth crash investigations of all fatal RTCs started in Norway in 2005. The aim of this study was to investigate whether fatal crash characteristics, vehicle safety features, and prevalence of drugs and/or alcohol among fatally injured drivers and riders has changed during 2005–2015, accompanying the reduction in road fatalities.

Methods: Data on all car/van drivers and motorcycle/moped riders fatally injured in RTCs during 2005–2015 were extracted from Norwegian road traffic crash registries and combined with forensic toxicology data.

Results: The proportion of cars and motorcycles with antilock braking systems and cars with electronic stability control, increased significantly during the study period. The prevalence of nonuse of seat belts/helmets and speeding declined among both fatally injured drivers and riders. In addition, the prevalence of alcohol declined, though no significant change in the total prevalence of other substances was noted.

Conclusion: The observed changes toward more safety installations in cars and motorcycles and lower prevalence of driver-related risk factors like alcohol use, speeding, and nonuse of seat belts/helmets among fatally injured drivers/riders may have contributed to the decrease in road traffic deaths.     

Driving under the influence of alcohol and the effects of alcohol prohibition—Case study in Serbia

Objective: The purpose of this study is to provide an overview of the prevalence of driving under the influence of alcohol (DUI) according to day of the week, specific roads (urban/rural), daytime or nighttime, and vehicle category. In addition, this study examines how the prohibition of selling alcoholic drinks in shops and supermarkets (not in restaurants) after 10 p.m. has affected the prevalence of DUI.

Method: Breath alcohol concentration (BrAC) was collected from all drivers through police checkpoints at 54 locations in Serbia. In this study, 17,945 drivers were tested in urban areas and 19,507 in rural areas. The relationship between DUI during the prohibition on alcohol sales in Belgrade and other large cities in Serbia was determined using logistic regression.

Results: On average, every 100th driver in traffic in Serbia was DUI (0.99%). This study shows that the 0 blood alcohol concentration (BAC) limit for motorcyclists does not have an influence on DUI. Moreover, motorcyclists represent the category with the highest share of DUI, with a statistically significantly larger difference compared to drivers of other vehicle categories. These results may be a consequence of the fact that a large number of drivers drive both motorcycles and other vehicle categories (cars or mopeds), so the different BAC limits for nonprofessional drivers may create confusion about the legal BAC limit.

Conclusions: This study suggests that the required legal BAC limit for nonprofessional drivers should be the same. The prohibition of selling alcoholic drinks in Belgrade after 10 p.m. does not decrease the prevalence of DUI.