职业中毒场所盲目施救行为的心理因素分析与对策研究

探讨职业中毒场所因盲目施救引发伤亡事故扩大的原因及控制对策,为企业和相关部门实施有效的安全管理提供依据。采用分析归纳方法,界定盲目施救行为。依据突发事件引发的紧急情况的特点,分析得出有限作业空间发生的中毒窒息事故属于常规突发事件。盲目施救导致伤亡扩大事故发生的主要行业和作业特性显示,安全监管的疏漏是事故发生的原因。根据社会心理学理论,对中毒人员的施救属于利他行为,盲目施救是人在应激状态下失控的冲动行为,这一行为与人对不安全行为的预期后果相关,应急知识和能力的缺乏是导致盲目施救行为发生的主要原因。根据上述研究结论,提出避免常规突发事件引发盲目施救行为的对策。     

基于博弈论石化园区火灾跨区域灭火救援研究

为解决石油化工园区火灾跨区域灭火救援面临的多消防中队相互协作、消防资源优化配置等复杂问题,搭建以新疆阿克苏地区消防力量为救援基础的原油储罐火灾场景,结合Gambit软件建立博弈计算模型,设计跨区域灭火救援方案的通用流程。针对不同火灾规模,以跨区域灭火救援通用制定流程为指导,计算出相应的消防中队战斗组合及救援力量输出。针对火灾发展的不确定性,通过混合策略博弈计算进一步调整和完善跨区域灭火救援方案。结果表明,采用博弈论方法能够提供针对消防资源调度分配的新方法,用以制定更快速和易于调整的灭火救援方案。     

北京市公交车内噪声监测与分析

公交车内噪声环境是影响驾驶员、售票员以及乘客乘车环境的重要物理因素.鉴于此,选取了北京3类15辆公交车进行了测量与分析.结果显示,北京公交车内噪声LAeq最高达到了79.6dB(A),噪声污染级最高达到91.9dB(A),交通噪声指数最高达96.3dB(A).显示北京公交车内噪声污染较为严重.此外对不同测点位置、不同类型车辆的噪声水平进行了方差分析.测点位置、车辆类型以及其交互效应均不存在显著差异(P＞0.05).频谱分析显示,车内噪声以低频为主,且呈现出显著的线性特征.铰链式公交车的部分高频成分较为显著.进一步计算发现NCB值均较高,车内存在较显著隆隆声和振动感,铰链式车辆的NCB值也显著高于其他两类公交车.为降低公交车内噪声强度,防止司售人员和乘客所处声环境的进一步恶化,建议相关部门采取有效措施进行控制.     

Characterization and sources of PAHs in an urban river system in Beijing,China

Water samples from 20 locations on rivers in the Tongzhou District of Beijing were collected four times from July 2005 to March 2006. In addition, sediment samples were collected in July 2005. All samples were analyzed for 16 US Environmental Protection Agency (EPA) priority pollutants polycyclic aromatic hydrocarbons (PAHs). The concentration, distribution, seasonal variation, and sources of the 16 PAH compounds identified in the water samples, suspended particles, and surface sediments were then evaluated. The concentrations of PAHs in the water and suspended particle and surface sediment samples ranged from 87.3 to 1,890 ng l⁻¹, 1,330 to 27,700 ng g⁻¹, and 156 to 8,650 ng g⁻¹, respectively. These results demonstrated that rivers in the Tongzhou District of Beijing had a high level of PAH pollution, especially in the suspended particles. The highest and lowest concentrations of PAHs in the water samples were observed in summer and spring. However, the seasonal variations in the concentration of PAHs in the suspended particles were more complicated. The dominant compounds in the water, suspended particle, and surface sediment samples were two-, three- and four-ring PAH compounds, respectively. Ratio analysis illustrated that fuel-burning was the primary source of PAHs in the study area. Gasoline, diesel, coal, and coke oven sources were identified and the contributions of the different fuel-burning sources were then calculated using factor analysis and multiple linear regression. These analyses revealed that coal combustion, gasoline combustion plus coke oven emission, and diesel combustion accounted for 38.8%, 38.5%, and 22.7% of the PAHs in suspended particles, respectively.     

Evaluation of wind environment around a residential complex using a PIV velocity field measurement technique

Wind-tunnel simulations were employed to evaluate the wind environment around a tested residential area located near industrial complexes. The scaled-down geomorphological model of the test area was placed in the test section of a boundary layer wind tunnel. Particle image velocimetry (PIV) measurements were made in five vertical planes and one horizontal plane around the test area for two prevailing wind directions. The results showed that the wind speed decreased in the near surface layer and the velocity fluctuations increased in the upper region due to the presence of hills and high-rise buildings around the test area. Regions of flow separation and low-speed flow were found inside the test area for both the wind directions. The result suggests that the high-rise buildings should be well arranged with respect to the main wind directions to increase the natural ventilation inside the residential complex at the initial design stage.     

基于支持向量机的采空区稳定性分级

针对采空区稳定性分级的影响因素众多且关系复杂的特点,提出采用支持向量机理论对采空区稳定性进行分级。根据分级评价指标选取原则,选取岩体结构、地质构造、岩石的质量指标、地下可见水、地下水体、周边开采的影响、相邻空区的情况、工程布置、跨度、面积、高度、矿柱的尺寸及布置、埋藏深度和采空区的规格14个影响因子,建立了采空区稳定性评价指标体系,引入支持向量机理论,选择有向无环图方式构造多类分类器,得到采空区稳定性分级的支持向量机模型。将该模型用于山东黄金矿业西山矿区的25个采空区进行分级,并与未确知测度方法的分级情况     

一种新型的MR隔震减振支座及其剪切性能试验研究

基于磁流变(MR)智能材料的减振器技术的研究可以为实现工程结构隔震减振自适应控制开辟一条新的途径。设计加工了一种新型的分体式MR隔震减振支座,并对该隔震减振支座的剪切性能进行了试验研究。新型MR隔震减振支座包含MR塑性体工作单元和MR弹性体工作单元,其中MR塑性体提供小位移工况时的刚度和阻尼,MR弹性体提供大位移工况时的刚度和阻尼。结果表明:新型MR隔震减振支座的剪切刚度随着工作电流强度的增大而增大,相较无电流工况,电流强度为2A时等效剪切刚度相对变化率可达到50%以上;无电流输入时支座中基体及普通填充橡胶仍可提供一定阻尼力,能够有效吸收振动能量,达到中高阻尼橡胶支座的性能;竖向压应力提高了新型MR隔震减振支座的剪切刚度;小位移时加载频率的降低对新型MR隔震减振支座的剪切刚度有增益效果。该新型MR隔震减振支座可以适用于震动荷载工况复杂多变,需要严格控制大位移变形的隔震结构物。     

循环温度荷载作用下饱和黏土的体积变形特性

采用温控三轴仪,研究了排水条件下温度循环引起的饱和黏土体积变化特性。试验结果表明,温度循环会使得土体产生不可恢复的体积变形,塑性体积应变的大小随温度循环周数的增加而增加,并逐渐趋于稳定值;若将经历过温度循环的土样重新加载到新的正常固结状态,后续温度循环中产生的塑性体积应变量值及发展规律与初始循环下的类似;同等温度增量下,体积应变的大小主要受超固结比OCR的影响,与应力水平无关。OCR越大,体积应变越小,随温度循环周数稳定的也越快。基于广义塑性理论,给出了热-力耦合作用下土体体积应变的计算模型。模型中考虑了温度塑性应变对屈服应力的硬化作用,根据屈服应力与前期固结应力之间的差异间接体现温度历史的影响,进而合理地模拟体积应变随温度循环周数的累积规律。利用所建立的模型对本文试验和文献中的数据进行了模拟,验证了模型的可靠性。     

As(III) adsorption onto Fe-impregnated food waste biochar: experimental investigation,modeling, and optimization using response surface methodology

Biochar derived from food waste was modified with Fe to enhance its adsorption capacity for As(III), which is the most toxic form of As. The synthesis of Fe-impregnated food waste biochar (Fe-FWB) was optimized using response surface methodology (RSM), and the pyrolysis time (1.0, 2.5, and 4.0 h), temperature (300, 450, and 600 °C), and Fe concentration (0.1, 0.3, and 0.5 M) were set as independent variables. The pyrolysis temperature and Fe concentration significantly influenced the As(III) removal, but the effect of pyrolysis time was insignificant. The optimum conditions for the synthesis of Fe-FWB were 1 h and 300 °C with a 0.42-M Fe concentration. Both physical and chemical properties of the optimized Fe-FWB were studied. They were also used for kinetic, equilibrium, thermodynamic, pH, and competing anion studies. Kinetic adsorption experiments demonstrated that the pseudo-second-order model had a superior fit for As(III) adsorption than the pseudo-first-order model. The maximum adsorption capacity derived from the Langmuir model was 119.5 mg/g, which surpassed that of other adsorbents published in the literature. Maximum As(III) adsorption occurred at an elevated pH in the range from 3 to 11 owing to the presence of As(III) as H₂AsO₃^? above a pH of 9.2. A slight reduction in As(III) adsorption was observed in the existence of bicarbonate, hydrogen phosphate, nitrate, and sulfate even at a high concentration of 10 mM. This study demonstrates that aqueous solutions can be treated using Fe-FWB, which is an affordable and readily available resource for As(III) removal.

     

Identification of iron and sulfate release processes during riverbank filtration using chemical mass balance modeling

Environmental Geochemistry and Health - Various hydrogeochemical processes can modify the quality of river water during riverbank filtration (RBF). Identifying the subsurface processes responsible...