An assessment of how distance and diesel oxidation catalyst will impact thermal decomposition behaviors of particles

Decomposition mass loss and pyrolysis products analyses of particles sampled at various locations along the tailpipe of a Euro-IV diesel engine were performed using a thermogravimetry in conjunction with Fourier transformation infrared spectrometry-mass spectrum. Diesel particles were collected at the same location with and without diesel oxidation catalyst (DOC) mounted on the test engine separately. The three poles in thermal gravity-differential thermal gravity images suggested that the decomposition process of diesel particles could be divided into three stages which correspond to the decompositions of lower boiling substances, higher boiling substances and soot respectively. It is noticed that no matter whether DOC was mounted or not, the further the particles were sampled away from the engine block, the lower the peak temperatures and the heavier the mass losses within the first two stages, which indicated that the soluble organic fraction in the particle samples increased and therefore lowering the activation energy of thermal decomposition. Hydroxyl, ammonia, C_xH_y fragments, benzene, toluene, and phenol were found to be the primary products of particle decomposition, which didn't change with the location of particle sample point. The employment of DOC increased the activation energy for particle oxidation and resulted in a higher peak temperature and lower mass loss within the first-stage. Moreover, the CO stretching bands of aldehyde and ketone at 1771 cm^?1 was only detected without a DOC, while the NO₂ peak at 1634 cm^?1 was solely noticed with the presence of DOC. Compared to the first-stage pyrolysis products, more polycyclic aromatic hydrocarbons and less C_xH_y fragments were seen in the second-stage.     

医疗废物管理信息系统的设计与开发研究

结合医疗废物无害化处理的运作管理,分析了医疗废物管理信息系统的数据流程,进行了系统设计,最终建立了长春市医疗废物管理信息系统,并阐述了该系统实现的主要技术特点。该系统利用条形码技术、GPS(全球卫星定位系统)、GPRS(General Packet RadioService)、在线监测等信息技术实现了对医疗废物的装载、运送、核实、焚烧、残渣处理的全程数字化跟踪管理。     

基于韦伯-费希纳定律的空气质量普适韦伯指数公式

在适当设定各项空气污染物浓度"参照值"cj0的基础上,用相应于"参照值"cj0的污染物的"规范值"xj作为基于韦伯-费希纳(W-F)定律空气质量指数公式中的污染刺激量。由于各污染物同级标准的浓度"规范值"xjl差异不大,从而可以认为各污染物的韦伯指数公式等效于一个具有共同适用的韦伯常数α的W-F指数公式,并采用粒子群(PSO)算法优化得出α,得到对7项空气污染物皆适用的空气质量普适韦伯指数公式。该公式应用于多个实例分析,并与多种其它评价方法的评价结果比较表明,空气质量普适韦伯指数公式具有简单、实用和直观的特点。     

北京某垃圾填埋区空气细菌浓度及粒径分布特征

以北京市某垃圾填埋区中作业区和覆盖区的空气细菌为主要研究对象,研究四个季节空气细菌浓度及粒径分布特征,得出了以下结论:垃圾填埋区作业区空气细菌浓度四季变化特征较覆盖区显著,且空气细菌浓度高于覆盖区。垃圾填埋区作业区和覆盖区四季的空气细菌粒子主要分布在前4级中,且在第Ⅵ级(<1.0μm)中分布比例最小,但分布规律不完全相同。秋季作业区最易感染人体的空气细菌浓度最高。垃圾填埋区作业区和覆盖区空气细菌中值直径最小值均出现在夏季,最大值均出现在冬季。     

北黄海北部海域潮余流的模拟研究

基于二维水动力模型,在仅考虑潮流作用条件下,通过计算欧拉余流和拉格朗日余流并结合粒子追踪方法研究了辽宁大连—朝鲜龙渊郡连线北侧的北黄海北部海域的潮余流结构和粒子运移的趋势。结果表明:欧拉余流和拉格朗日余流流速整体较小,呈现由南向北的流向,但在獐子岛及长山群岛的附近岛屿和朝鲜半岛沿岸的海域欧拉余流和拉格朗日余流流速较大。对比粒子追踪计算的结果与欧拉余流和拉格朗日余流的结果表明,流向与粒子运移路径基本一致。该海湾的余流及粒子运动规律特点对辽东半岛东岸及朝鲜半岛西侧海域的排污及污染控制有重要的借鉴意义。     

水环境中溶解性有机物溯源分析及分子结构表征概述

溶解性有机物(DOM)是地球上最大的碳基化合物反应性储层之一,涉及各种生物地化反应并且在污染物溶解度、毒性、生物利用度、流变性和分布中发挥重要作用。本文介绍了当前用于表征水环境中DOM的策略和工具,探讨了当前研究在技术限制(预处理过程复杂、仪器分辨率低、数据处理困)、结构复杂性、结构多变性等方面存在的诸多局限性。分析认为:已有研究主要侧重于溯源分析和分子结构特征解析,未来研究应该在不同的结构层面和角度开展,加强多学科融合、数据库创建、对照实验和协同工作。     

脑力疲劳与非疲劳状态眼动指标的判别

为研究利用眼动指标(注视点个数FC、平均注视时间AFD、平均眼跳幅度ASA、最大瞳孔面积Pupil Max及反应时RD)对脑力疲劳状态进行判定,通过眼动追踪技术,测试了不同脑力疲劳程度的眼动指标值并进行分析。结果表明:1)通过FC、AFD、ASA和Pupil Max四个眼动指标可以判定被试者所处的疲劳状态; 2)当测试者注视点个数FC处于(11,13)区间,平均注视时间AFD处于(328,409)区间,平均眼跳幅度ASA处于(5,7)区间,最大瞳孔面积Pupil Max处于(992,1 124)区间时为非疲劳状态;当FC处于(7,10)区间,AFD处于(263,319)区间,ASA处于(2,4)区间,最大瞳孔面积Pupil Max处于(584,935)时可以认定被试者为疲劳状态。     

山区高速公路空间郁闭度对驾驶员视觉及生理指标的影响

为了解高速公路空间郁闭度对驾驶员视觉行为和心理状态的影响规律,在山区高速公路开展室外实车试验,采用Dikablis眼镜式眼动仪和Varioport生理记录仪记录了驾驶员的眼动和生理数据,包括注视时间百分比、平均注视时间、扫视幅度、眨眼率、心电、心率、皮电等。结果表明,随空间郁闭度增加,驾驶员皮电和扫视幅度增大,眨眼率和平均注视持续时间减小,视点越来越集中。随着驾驶员的逐渐适应,空间环境对驾驶员的心理影响逐渐减弱。驾驶员主要关注中间靠左区域,目标物为中央分隔带和前方道路。开敞空间下驾驶员对右侧区域有少量关注。半郁闭空间下驾驶员皮电呈现规律性的波动,对于左侧区域的关注明显增多,对右侧区域的注视持续时间较长,视点集中点更远。     

Implications of network particle tracking (NPT) for ecological model interpretation

Network particle tracking (NPT), building on the foundation of network environ analysis (NEA), is a new development in the definition of coherence relations within and between connected systems. This paper evaluates three ecosystem models in a comparison of throughflow- and storage-based NEA and NPT. Compartments in models with high indirect effects and Finn cycling showed low correlation of NEA storage and throughflow with particle repeat visits and numbers of particles in compartments at steady state. Conversely, the correlation between NEA and NPT results was high with two models having lower indirect effects and Finn cycling. Analysis of ecological orientors associated with NEA showed NPT to fully support conventional NEA results when the common conditions of donor control and steady state are satisfied. Particle trajectories are recorded in the new concept of a particle “passport”. Ability to track and record particle in-system histories enables views of multiple scales and opens the possibility of making pathway-dependent modeling decisions. NPT may also enable modeling of time, allowing integration of Newtonian, organismal and stochastic modeling perspectives in a single comprehensive analysis.     

Tracking the response of industrial fishing fleets to large marine protected areas in the Pacific Ocean

Large marine protected areas (MPAs) of unprecedented size have recently been established across the global oceans, yet their ability to meet conservation objectives is debated. Key areas of debate include uncertainty over nations’ abilities to enforce fishing bans across vast, remote regions and the intensity of human impacts before and after MPA implementation. We used a recently developed vessel tracking data set (produced using Automatic Identification System detections) to quantify the response of industrial fishing fleets to 5 of the largest MPAs established in the Pacific Ocean since 2013. After their implementation, all 5 MPAs successfully kept industrial fishing effort exceptionally low. Detected fishing effort was already low in 4 of the 5 large MPAs prior to MPA implementation, particularly relative to nearby regions that did not receive formal protection. Our results suggest that these large MPAs may present major conservation opportunities in relatively intact ecosystems with low immediate impact to industrial fisheries, but the large MPAs we considered often did not significantly reduce fishing effort because baseline fishing was typically low. It is yet to be determined how large MPAs may shape global ocean conservation in the future if the footprint of human influence continues to expand. Continued improvement in understanding of how large MPAs interact with industrial fisheries is a crucial step toward defining their role in global ocean management.