高原湖泊砷污染健康风险评估

以某高原湖泊为例,以湖水中的砷含量类比推算了从该湖泊取水灌溉区域内水稻和蔬菜的砷含量,对稻米、蔬菜和饮水3种暴露途径进行健康风险评估。结果表明,人群通过摄入区域内稻米、蔬菜的致癌风险系数为可接受的致癌风险,饮用湖水的致癌风险系数为不可接受的致癌风险。     

Model-based zero emission safety concept for reactors with exothermal reactions for chemical plants

To avoid major accidents caused by runaway reactions, a new safety concept called SmartHIP¹ is introduced, with the objective to prevent runaway reactions and avoid emissions. The basic principle is based on an online model-based approach by using safety instrumented systems. Different criteria exist for calculating the hazard potential of a runaway reaction and its early detection. The approaches of the literature from the last years are analysed and divided into three different groups: Divergence, Accumulation and Adiabatic Criterion. Each approach is compared to the other by applying it to an esterification reaction of acetic anhydride with methanol. The approaches are evaluated according to different requirements, like accuracy, wide range of application or reliability.     

Unintentional injury deaths in children and youth, 2010–2019

Background: Unintentional injuries are the leading cause of death for children and youth aged 1–19 in the United States. The purpose of this report is to describe how unintentional injury death rates among children and youth aged 0–19 years have changed during 2010–2019. Method: CDC analyzed 2010–2019 data from the National Vital Statistics System (NVSS) to determine two-year average annual number and rate of unintentional injury deaths for children and youth aged 0–19 years by sex, age group, race/ethnicity, mechanism, county urbanization level, and state. Results: From 2010–2011 to 2018–2019, unintentional injury death rates decreased 11% overall—representing over 1,100 fewer annual deaths. However, rates increased among some groups—including an increase in deaths due to suffocation among infants (20%) and increases in motor-vehicle traffic deaths among Black children (9%) and poisoning deaths among Black (37%) and Hispanic (50%) children. In 2018–2019, rates were higher for males than females (11.3 vs. 6.6 per 100,000 population), children aged < 1 and 15–19 years (31.9 and 16.8 per 100,000) than other age groups, among American Indian or Alaska Native (AIAN) and Blacks than Whites (19.4 and 12.4 vs. 9.0 per 100,000), motor-vehicle traffic (MVT) than other causes of injury (4.0 per 100,000), and rates increased as rurality increased (6.8 most urban [large central metro] vs. 17.8 most rural [non-core/non-metro] per 100,000). From 2010–2011 to 2018–2019, 49 states plus DC had stable or decreasing unintentional injury death rates; death rates increased only in California (8%)—driven by poisoning deaths. Conclusion and Practical Application: While the overall injury death rates improved, certain subgroups and their caregivers can benefit from focused prevention strategies, including infants and Black, Hispanic, and AIAN children. Focusing effective strategies to reduce suffocation, MVT, and poisoning deaths among those at disproportionate risk could further reduce unintentional injury deaths among children and youth in the next decade.     

Consumer reflections on the usage of plastic bags to parcel hot edible items: an empirical study in Malaysia

The packaging industry offers a wide range of pouching products to their clients in the food and beverage industries, healthcare industries and households as well. It is observed that pouching products are widely used and seemingly making them indispensable. Such practices are commonly found in Malaysia especially to parcel hot or cold food. The use of pouches raises two concerns namely solid waste disposal and food safety. The present study found more than 62% of the consumers purchase hot edible items in plastic bags daily or weekly because of its cost effectiveness and storage convenience. Consumers apparently are unperturbed by public campaigns against the use of plastic bags and neither do government regulations have any influence to reduce the use of plastic bags to parcel hot edible items. On the other hand, consumers are optimistic that the environmental and health hazards from the use of plastic bags to store hot edible items would only see a positive impact in the future.     

自然环境谱编制方法研究

针对装备(产品)在服役过程中所遭受的自然环境开展了自然环境谱编制方法研究,给出了自然环境谱的定义和编制程序,提出了盐雾和工业废气环境的判定标准,制定了适用于我国各种大气环境场地自然环境谱的编制方法,并举例编制了某地域的自然环境谱.     

A review on hybrid mixture explosions: Safety parameters,explosion regimes and criteria,flame characteristics

The hybrid mixture of combustible dusts and flammable gases/vapours widely exist in various industries, including mining, petrochemical, metallurgical, textile and pharmaceutical. It may pose a higher explosion risk than gas/vapor or dust/mist explosions since the hybrid explosions can still be initiated even though both the gas and the dust concentration are lower than their lower explosion limit (LEL) values. Understanding the explosion threat of hybrid mixtures not only contributes to the inherent safety and sustainability of industrial process design, but promotes the efficiency of loss prevention and mitigation. To date, however, there is no test standard with reliable explosion criteria available to determine the safety parameters of all types of hybrid mixture explosions, nor the flame propagation and quenching mechanism or theoretical explanation behind these parameters. This review presents a state-of-the-art overview of the comprehensive understanding of hybrid mixture explosions mainly in an experimental study level; thereby, the main limitations and challenges to be faced are explored. The discussed main contents include the experimental measurement for the safety parameters of hybrid mixtures (i.e., explosion sensitivity and severity parameters) via typical test apparatuses, explosion regime and criterion of hybrid mixtures, the detailed flame propagation/quenching characteristics behind the explosion severities/sensitivities of hybrid mixtures. This work aims to summarize the essential basics of experimental studies, and to provide the perspectives based on the current research gaps to understand the explosion hazards of hybrid mixtures in-depth.     

确定卫生防护距离应注意的问题

本文总结了石化行业卫生防护距离标准编制和环境影响评价工作中的经验，对确定卫生防护距离时应注意的一些问题进行了探讨，并提出了一种新的确定石化装置废气无组织排放量的方法。     

Definition of Planarian Mortality in an Acute Toxicity Test: A Case Study on Dugesia japonica Exposed to 1-Octyl-3-methylimidazolium Bromide

In order to define the mortality criteria of planarian objectively,a case study of Dugesia japonica exposed to 1-octyl-3-methylimidazolium bromide([C8mim]Br)was performed followed by a recovery culture.The results showed that defining planarian mortality in light of its body disintegration was appropriate.If the disintegrated tissue of a planarian was more than 1/4 of its body length,it would completely degenerate.However,a planarian would regenerate the lost tissue and return to normal after a few days’recovery culture if the disintegrated part was less than 1/4 of body length.Therefore,we propose to use body disintegration as the endpoint of planarian mortality,i.e.,1/4 body length degenerated is the critical threshold of mortality and survival of planarians when exposed to toxicants.This criterion could be adapted in the standardization of testing protocols and comparability of acute toxicity test or other toxicological research using planarian as the test animal.     

考虑损伤的圆形巷道围岩弹塑性分析

如何判断巷道开挖后,围岩弹塑性变形及围岩的力学行为一直是人们研究的重点问题。考虑岩石材料的损伤特性,建立了巷道围岩弹塑性损伤力学模型,对侧压力系数为1时圆形巷道围岩的弹塑性应力场及范围进行分析。结合具体算例,得出在相同塑性范围内,随着λ/E比值的增大,所需要的支护阻力也随之增大;当原岩应力一定时,随着λ/E比值的增大,巷道围岩的塑性区范围也随之增加。研究表明,考虑损伤作用使得分析结果更加接近于实际,从而为巷道围岩稳定性分析和合理选择支护形式及强度提供理论依据。     

混凝土复合型裂缝的断裂能及其判据研究

首先通过理论分析得到断裂能与能量释放率的关系,继而根据试验研究测出的单一型裂缝的断裂能,进行单一型裂缝断裂能与断裂韧度的相关性分析,得到了单一型裂缝的断裂能与能量释放率之间的关系,再进行数值模拟,获得混凝土复合型裂缝的断裂能。基于Ⅰ型、Ⅱ型、Ⅲ型、二维复合型(Ⅰ-Ⅱ、Ⅰ-Ⅲ、Ⅱ-Ⅲ)和三维复合型(Ⅰ-Ⅱ-Ⅲ)的应力强度因子断裂临界曲线和临界曲面(即完整的系列K判据),通过各复合型裂缝的断裂韧度,得到相应的能量释放率,进而获得复合型裂缝的断裂能,绘出断裂能临界曲线和曲面,从而建立了完整的系列断裂能G判据。