石油化工装置区火灾举高消防车的安全部署研究

举高消防车广泛应用在石油化工装置区火灾中。为高效发挥举高消防车在石油化工装置区火灾中的作用,对石油化工装置区火灾中广泛使用的举高消防车的结构性能进行了分析,针对举高喷射消防车的特点,分析了装置类型、作业场地、安全工作范围、火场热辐射对其在石油化工装置区火灾使用中的影响。分析给出了石油化工装置区火灾中消防通道的要求、举高消防车距离火源的安全距离及其臂架的工作要求,并提出了举高消防车在石油化工装置区火灾中的安全部署要求。研究结果可以为举高消防车在石油化工装置区火灾中的安全部署及作战效能的提高提供技术支持。     

Critical factors for the recovery of marine mammals

{en} Over the past decades, much research has focused on understanding the critical factors for marine extinctions with the aim of preventing further species losses in the oceans. Although conservation and management strategies are enabling several species and populations to recover, others remain at low abundance levels or continue to decline. To understand these discrepancies, we used a published database on abundance trends of 137 populations of marine mammals worldwide and compiled data on 28 potentially critical factors for recovery. We then applied random forests and additive mixed models to determine which intrinsic and extrinsic factors are critical for the recovery of marine mammals. A mix of life‐history characteristics, ecological traits, phylogenetic relatedness, population size, geographic range, human impacts, and management efforts explained why populations recovered or not. Consistently, species with lower age at maturity and intermediate habitat area were more likely to recover, which is consistent with life‐history and ecological theory. Body size, trophic level, social interactions, dominant habitat, ocean basin, and habitat disturbance also explained some differences in recovery patterns. Overall, a variety of intrinsic and extrinsic factors were important for species’ recovery, pointing to cumulative effects. Our results provide insight for improving conservation and management strategies to enhance recoveries in the future.     

宽域灰色聚类法在土壤环境质量评价中的应用

利用宽域灰色聚类法评价土壤环境质量,先构造白化函数,引入修正系数,确定污染物权重,再计算聚类系数实现土壤样本的环境质量等级评判与排序。将此方法应用于太原市5个区县,8项指标的土壤质量评价,并与综合指数法、模糊综合评判法相比较,结果表明模糊综合评判法与宽域灰色聚类法对于5个区县的污染级别的评价结果是一致的,而综合指数法对前四个评价点级别均比上述两种方法低一个级别,三种方法的质量排序大致相同,只有模糊综合评价中认为小店区优于万柏林区。     

Neighborhood attachment and its correlates: Exploring neighborhood conditions, collective efficacy, and gardening

Neighborhood attachment relates to one’s emotional connection to physical and social environments. Such bonds are critical for shaping how people interact with their local environments, connect with others and may be vital for fostering sustainable health behavior change related to nutrition and physical activity. Using data from a population-based survey of neighborhood environments and health in Denver, Colorado (n = 410 respondents; n = 45 block-groups) and hierarchical linear modeling techniques, we examined the relationship between objective and perceived neighborhood conditions (e.g., crime, physical incivilities, sense of safety), social processes (e.g., collective efficacy) and recreational gardening and neighborhood attachment. Results indicate length of residency, collective efficacy, and home and community garden participation are associated with neighborhood attachment. Further research is warranted to consider neighborhood attachment as an intervening mechanism through which gardens and other outdoor everyday places may influence health behavior change.     

基于GIS的某训练场土壤重金属污染评价

以中国西南地区某训练场的坦克射击区为研究对象,监测并分析了土壤中Pb、Cu、Zn、Co和Ni的含量;采用单因子指数法和内梅罗综合污染指数法评价了采样区的重金属污染状况,同时运用Arcgis软件分析制定出了采样区的污染指数分布图.评价结果表明,坦克射击区Pb、Cu、Zn、Co和Ni分别存在不同程度的污染,重金属内梅罗综合污染指数平均为1.64;Co的单因子指数最高达到了3.84,是未来土壤重金属污染控制中优先关注的元素;污染指数分布图显示,落弹区土壤的重金属污染尤为严重.Cu和Pb污染分布特征较相似,Zn、Co、Ni特征较相似.分析认为,在射击场各种条件综合作用下,Ni和Pb扩散性较强,Cu扩散性较弱;重金属污染源来自于炮弹残片、子弹弹头、火炸药等;残留在土壤中的炮弹残片和子弹弹头会给土壤带来持久性的重金属污染.     

Removal of cadmium using MnO2 loaded D301 resin

MnO2 loaded weak basic anion exchange resin D301 （Anion exchange resin, macroreticular weak basic styrene） as adsorbent has been prepared and applied to the removal of cadmium. The adsorption characteristics have been investigated with respect to effect of pH, equilibrium isotherms, removal kinetic data, and interference of the coexisting ions. The results indicated that the Cd^2＋ could be efficiently removed using MnO2 loaded D301 resin in the pH range of 3-8 from aqueous solutions with the co-existence of high concentration of alkali and alkaline-earth metals ions. The saturate adsorption capacity of the Cd^2＋ was 77.88 mg/g. The adsorption process followed the pseudo first-order kinetics. The equilibrium data obtained in this study accorded excellently with the Langmuir adsorption isotherm.     

Formaldehyde degradation by UV/TiO2/O3process using continuous flow mode

The degradation of formaldehyde gas was studied using UV/TiO2/O3 process under the condition of continuous flow mode. The effects of humidity, initial formaldehyde concentration, residence time and ozone adding amount on degradation of formaldehyde gas were investigated. The experimental results indicated that the combination of ozonation with photocatalytic oxidation on the degradation of formaldehyde showed a synergetic action, e.g,, it could considerably increase decomposing of formaldehyde. The degradation efficiency of formaldehyde was between 73.6% and 79.4% while the initial concentration in the range of 1.84--24 mg/m^3 by O3/TiO2flJV process. The optimal humidity was about 50% in UV/TiO2/O3 processs and degradation of formaldehyde increases from 39.0% to 94.1% when the ozone content increased from 0 to 141 mg/m^3. Furthermore, the kinetics of formaldehyde degradation reaction could be described by Langmuir-Hinshelwood model. The rate constant k of 46.72 mg/（m^3.min） and Langmuir adsorption coefficient K of 0.0268 m^3/mg were obtained.     

Disparities in the prevalence of smoke alarms in U.S. households: Conclusions drawn from published case studies

Introduction

Deaths from fires and burns are a leading cause of fatal home injury in the United States. Smoke alarms are one of the most effective interventions to prevent residential fire deaths. Nationwide, more than 95% of homes are estimated to have at least one smoke alarm. There is evidence that homes at highest risk of fire deaths lag behind national averages in smoke alarm use and maintenance.

Method

We compiled a comprehensive list of published studies that focus on smoke alarm prevalence in high-risk homes. Our findings show that there are substantial gaps in both smoke alarm presence and functional status between high-risk homes and national average estimates.

Conclusions

To save more lives, improved efforts are needed to reduce the disparity in smoke alarm prevalence and functional use in the United States.     

贮存老化对某弹药射程的影响研究

目的 研究长期贮存老化对某弹药射程的影响,确定其有效增程射角范围。方法 对130 mm某弹药在不同贮存老化时间下的射程进行数值仿真分析,揭示其射程和有效增程射角范围随贮存时间的变化规律。结合射程与贮存老化时间和射角之间的函数关系,提出以剩余推力比为表征参数的射程变化模型。结果 在相同贮存老化时间下,随着射角的增大,该弹药的射程呈现出先增大、后减小的趋势。相同射角下,射程随贮存老化时间呈线性下降趋势,有效增程射角范围逐渐减小。使用三次多项式拟合有效增程比与射角之间的函数关系,拟合方程的相关系数超过了0.997 0。该弹药射程变化模型的拟合结果与仿真计算结果的相关系数大于0.998 5,表明其可以准确描述该弹药的射程变化规律。结论 贮存老化会显著影响某弹药的射程和有效增程射角范围,在实际贮存和使用过程中,不能忽略其贮存老化因素。     

Long-term global availability of steel scrap

Primary steelmaking involves CO₂-intensive processes, but the expansion of secondary steel production is limited by the global availability of steel scrap. The present work examines global scrap consumption in the past (1870–2012) and future scrap availability (2013–2050) based on the historical trend. The results reveal that (i) historically, the consumption of old scrap has been insufficient compared with the amounts of discarded steel, and (ii) based on historical scrap consumption, the future availability of scrap will not be sufficient to satisfy the two assumed cases of steel demand. Primary steelmaking is expected to remain the dominant process, at least up until 2050. Under the reference-demand case of 2.19 billion tons in crude steel production by 2050, the total production of pig iron and direct reduced iron could reach 1.35 billion tons. Consumption of old scrap could reach 0.76 billion tons. Because the availability of scrap will be limited in the context of the global total, it is important to research and develop innovative low-carbon technologies for primary steelmaking and to explore their economic viability if we are to aim for achieving large reductions in CO₂ emissions from the iron and steel industry.