成品油铁路装运站危险有害因素分析及安全措施

以某成品油装运站为例进行危险有害因素分析,探讨油品装运站危害识别与风险评估,为事故调查分析与事故预防提供科学依据,达到提高安全生产管理和事故预防水平的目的。     

采空区进风侧煤柱着火进行灭火时防止瓦斯爆炸的对策

以孔庄煤矿Ⅲ2水采区7337回风联络巷自然发火情况及处理经过为例,笔者介绍了在采空区瓦斯浓度较高情况下,采空区进风煤柱着火的火势发展情况与着火特点。分析灭火过程发生瓦斯爆炸的可能性;提出了在安全前提下灭火步骤、灭火措施和注意事项;总结了灭火工作中成功的经验与失败的教训,即在扑灭井下火灾过程中,必须做到:遵循“安全第一”的方针,制定科学、具体的灭火方案和正确、有效的灭火措施,要时刻加强火区气体成分检测,得出了防止瓦斯爆炸等一系列具有指导性的原则和行之有效的措施。     

Can variations in visual behavior measures be good predictors of driver sleepiness? A real driving test study

Objective: The primary purpose of this study was to examine the association between variations in visual behavior measures and subjective sleepiness levels across age groups over time to determine a quantitative method of measuring drivers' sleepiness levels.

Method: A total of 128 volunteer drivers in 4 age groups were asked to finish 2-, 3-, and 4-h continuous driving tasks on expressways, during which the driver's fixation, saccade, and blink measures were recorded by an eye-tracking system and the subjective sleepiness level was measured through the Stanford Sleepiness Scale. Two-way repeated measures analysis of variance was then used to examine the change in visual behavior measures across age groups over time and compare the interactive effects of these 2 factors on the dependent visual measures.

Results: Drivers' visual behavior measures and subjective sleepiness levels vary significantly over time but not across age groups. A statistically significant interaction between age group and driving duration was found in drivers' pupil diameter, deviation of search angle, saccade amplitude, blink frequency, blink duration, and closure duration. Additionally, change in a driver's subjective sleepiness level is positively or negatively associated with variation in visual behavior measures, and such relationships can be expressed in regression models for different period of driving duration.

Conclusions: Driving duration affects drivers' sleepiness significantly, so the amount of continuous driving time should be strictly controlled. Moreover, driving sleepiness can be quantified through the change rate of drivers' visual behavior measures to alert drivers of sleepiness risk and to encourage rest periods. These results provide insight into potential strategies for reducing and preventing traffic accidents and injuries.     

2017年厦门金砖会晤期间气象因素与管控措施对空气质量的影响

2017年厦门金砖会晤期间采取了大气污染临时管控措施,使AQI小时值和日均值均达到了双优的预期目标.本文根据管控措施实施的前、中、后阶段,厦门及周边城市大气污染物浓度的变化,对气象因素和人为因素的影响分别进行分析.结果发现,气态污染物对临时管控措施的敏感性最强,SO₂和NO₂的降幅（39.9%和25.6%）明显高于PM_2.5和PM₁₀的降幅（5.5%和4.8%）,台风外围带来的大风和降水可显著改变大气污染物的周期性变化规律.大气PM_2.5组成及SO₂/NO₂、SO₄^2-/NO₃^-、OC/EC和WSOC/OC等比值变化显示机动车（尤其是柴油货车）是本地区大气污染物的重要来源.控制变量分析显示,厦门金砖会晤期间气象因素对颗粒物和NO₂削减的贡献更大（20.3%）,而临时管控措施对SO₂的削减效果更明显（23.2%）,且有一半以上（51%~64%）的大气污染物来自外来源输送.     

生产力与生物多样性关系的研究进展

生产力和生物多样性是生态系统两个基本属性。然而,几十年来,人们一直在争论它们之间的相互关系及其潜在机制。论文综述过去有关两者关系的控制实验、meta分析、多点观测研究和潜在机制,发现两者关系主要表现为单峰关系、正相关关系、负相关关系、无关系、“U”型关系,并且关于它们关系的潜在机制也没有普遍共识。同时,两者关系及其潜在机制均对尺度具有很强依赖性。分析其原因,可能生产力与生物多样性的关系不是简单或直接因果关系,而是由相互关联的、多变量过程共同控制。因此,应放弃固定化二元模式,开展多元化驱动因素的生物多样性研究,加强人类对复杂生态系统过程的理解,提供更具意义的生物多样性保护和管理指导。     

基于高通量测序检测Pb污染对三叶草根际土壤细菌多样性的影响

为了研究Pb污染对根际土壤微生物多样性的影响,揭示根际微生物对Pb胁迫的适应性机制,通过盆栽试验模拟轻度[w（Pb）为300 mg/kg]、中度[w（Pb）为600 mg/kg]和重度[w（Pb）为900 mg/kg]Pb污染土壤环境,利用高通量测序技术和生物信息学分析方法,测定了不同w（Pb）处理下三叶草根际土壤中细菌群落的丰度和组成.结果表明:①共检测到37个门,其中变形菌门为优势菌群,占比为50.7%~53.9%,其次为拟杆菌门、酸杆菌门和疣微菌门. ②共检测到623个属,其中鞘氨醇单胞菌属为优势菌属,占比为17.1%~19.4%. ③中度Pb污染土壤样本中细菌的多样性最高,重度Pb污染土壤样本中的细菌数量最少,并且其群落组成与其他处理差异最大.研究显示,重度Pb污染会显著抑制三叶草根际土壤样本中细菌的生长,降低土壤样本中细菌总量及其群落的多样性,但中度Pb污染会提高土壤样本中细菌群落的多样性. Pb污染会改变三叶草根际土壤样本中细菌群落组成和丰度,不同类型细菌对Pb污染土壤的适应性不同.根际土壤样本中Gp1菌群的丰度随着土壤w（Pb）的增加而增加,说明Gp1菌群可能是具有Pb污染抗性的优势菌群.      

中国含铅汽油税收政策的设计

征收含铅汽油税是实行汽油无铅化的一项重要政策。本文提出了含铅汽油税收政策的基本框架,设计了含铅汽油税的三个方案,并预测了征收含铅汽油税对消费者和汽油市场价格的影响。最后,建议在我国尽快实施含铅汽油税。     

生物多样性研究进展

生物多样性是自然资源中的一个重要组成部分。在最近的40年内,生物多样性的研究发展很迅速,有关多样性的测定方法已形成了数十个数学模型和多样性指数。生物多样性的功能也研究得比较多,生物多样性的保护技术也已逐渐系统化,并开始了持续利用和合理开发的研究。     

Remarkable Amphibian Biomass and Abundance in an Isolated Wetland: Implications for Wetland Conservation

Abstract:  Despite the continuing loss of wetland habitats and associated declines in amphibian populations, attempts to translate wetland losses into measurable losses to ecosystems have been lacking. We estimated the potential productivity from the amphibian community that would be compromised by the loss of a single isolated wetland that has been protected from most industrial, agricultural, and urban impacts for the past 54 years. We used a continuous drift fence at Ellenton Bay, a 10-ha freshwater wetland on the Savannah River Site, near Aiken, South Carolina (U.S.A.), to sample all amphibians for 1 year following a prolonged drought. Despite intensive agricultural use of the land surrounding Ellenton Bay prior to 1951, we documented 24 species and remarkably high numbers and biomass of juvenile amphibians (>360,000 individuals; >1,400 kg) produced during one breeding season. Anurans (17 species) were more abundant than salamanders (7 species), comprising 96.4% of individual captures. Most (95.9%) of the amphibian biomass came from 232095 individuals of a single species of anuran (southern leopard frog [Rana sphenocephala ]). Our results revealed the resilience of an amphibian community to natural stressors and historical habitat alteration and the potential magnitude of biomass and energy transfer from isolated wetlands to surrounding terrestrial habitat. We attributed the postdrought success of amphibians to a combination of adult longevity (often >5 years), a reduction in predator abundance, and an abundance of larval food resources. Likewise, the increase of forest cover around Ellenton Bay from <20% in 1951 to >60% in 2001 probably contributed to the long-term persistence of amphibians at this site. Our findings provide an optimistic counterpoint to the issue of the global decline of biological diversity by demonstrating that conservation efforts can mitigate historical habitat degradation.     

宁夏盐池封育区植物特征值及多样性影响

封育措施是一种主要的草场恢复和重建的措施。通过对半干旱沙地老封育、新封育和对照区的比较分析,量化了不同封育措施下植被变化。对3种封育措施群落组成和生物多样性的分析结果表明,封育改变了群落的组成成分并增加了生物多样性,同时对群落植物的生活型、饲用价值分析计算结果则显示,老封育的群落植物逐渐向多年生发展,放牧价值开始降低,而对照区则明显处于一种非平衡的稳定状态。从3种措施植被的盖度、高度、生物量和饲用价值来看,老封育区均低于新封育区和对照区,表明长期封育不利于促进并提高草场的放牧利用价值。