城市污泥与谷壳混合制备吸附剂的研究

以氯化锌为活化剂,城市污泥与谷壳为原料热解制备含碳吸附剂,通过单因素实验和正交实验确定最佳制备条件,并对吸附剂进行了SEM和比表面积分析。最佳制备条件为:污泥谷壳干重比2∶3,ZnCl2浓度4 mol/L,固液比1∶2.5,热解温度500℃。比表面积测试结果为560.4 m2/g,SEM分析也表明制得的吸附剂孔道发达,说明该吸附剂适合做吸附材料。     

活化剩余污泥对Pb2+的吸附热力学研究

以城市污水处理厂脱水干污泥为原料,以浓硫酸为活化剂,制备活化剩余污泥吸附剂,采用正交试验法考察了Pb2+初始质量浓度、初始pH值、吸附温度、活化剩余污泥投加量对活化剩余污泥吸附性能的影响.结果表明,活化剩余污泥对Pb2+的最佳吸附条件为pb2+初始质量浓度60 mg/L、初始pH值5、活化剩余污泥投加量100mg、吸附温度288 K,影响从高到低的各因素为Pb2+初始质量浓度、吸附温度、初始pH值、活化剩余污泥投加量.采用Langmuir、Freundlich、D-K-R吸附等温方程对不同温度下的吸附平衡试验数据进行拟合.Langmuir吸附等温方程可以较好地描述活化剩余污泥对pb2+的吸附平衡过程.其吸附过程吉布斯自由能△G为-3.35 ～-0.32 kJ/mol,焓变△H和熵变△S均为负值,表明活化剩余污泥对pb2+的吸附是自发的、以物理吸附为主的放热反应.     

高吸附性能芦苇活性炭的制备方法研究

为实现白洋淀芦苇的有效利用,以白洋淀淀区芦苇(白苇)为原料,以KOH、K2CO3为活化剂,综合考虑制备过程中的剂料比、浸渍时间、活化温度、活化时间等因素的影响,通过正交试验,以碘吸附值和亚甲蓝吸附值综合作为吸附性能高低的评价标准,进行活性炭制备方法研究。结果表明:在以KOH为活化剂、剂料比为4∶1、浸渍时间36 h、850℃下活化1 h的条件下,制备的芦苇基生物质活性炭碘吸附值最高,亚甲基蓝吸附值较高;以K2CO3为活化剂、剂料比为3∶1、浸渍时间12 h、900℃下活化2 h的条件下,制备的芦苇基生物质活性炭有最高的碘吸附值和对亚甲蓝具有良好的吸附性。制备的生物质活性炭碘吸附值均高于国家活性炭一级品标准(1 000 mg/g),具备一定的实用性。     

基于KOH活化法的核桃壳基活性炭制备及其表征

采用农林废弃物制备比表面积大、微孔结构发达的活性炭,能够缓解资源短缺问题,减少环境污染,并且提高活性炭在气相吸附方面的利用价值。以核桃壳为原料、KOH为活化剂,采用单因素法探讨碱炭比、活化温度和活化时间对活性炭得率、碘吸附值的影响,确定了核桃壳基活性炭制备的最佳工艺条件。采用场发射扫描电镜、孔径分析仪、傅里叶红外光谱仪分析了活性炭的微观形貌、孔径结构、表面化学性质。结果表明:当碱炭比为3∶1、活化时间为60 min、活化温度为800℃时,制备的核桃壳基活性炭的比表面积为1 551.85 m2/g,总孔容为0.79 cm3/g,微孔比表面积为1 491.22 m2/g,微孔率为89.87%。该活性炭的比表面积大,微孔结构发达,同时极微孔含量很高。     

球形磁性活性炭制备及对土壤重金属Pb的吸附研究

以废旧汽车轮胎橡胶与城市污水处理厂污泥为原料,采用ZnCl2与H_2SO_4复配活化法,添加黏结剂和Fe_3O_4粉末,在真空管式气氛炉中炭化制备球形磁性活性炭,并测定其物理化学性能。研究球形磁性活性炭添加量、土壤pH值和含水率对球形磁性活性炭吸附重金属Pb的影响。采用火焰法-原子吸收分光光度计测定球形磁性活性炭对Pb的吸附量。结果表明:球形磁性活性炭的比表面积及亚甲基蓝吸附量相比商品活性炭要小,但其抗压强度高,不容易松散,便于回收,酸性官能团总量高,有助于提高球形磁性活性炭的吸附性能和对重金属的亲和力,因此球形磁性活性炭的综合理化性能优于干污泥活性炭和商品活性炭,适合用于土壤中重金属Pb的吸附;随添加量增加,球形磁性活性炭对土壤中Pb的吸附量也增加,当球形磁性活性炭添加质量分数为6%时,达到最优吸附效果;随土壤pH值增加,球形磁性活性炭对土壤中Pb的吸附量也增加,但当pH值超过5时,其吸附量开始下降;当吸附时间达到35 d后,其吸附量基本处于饱和状态;土壤含水率为20%时,吸附达到平衡。在最优工艺参数下,球形磁性活性炭对土壤中Pb的吸附量达到最大,为3.55 mg/g。球形磁性活性炭对土壤中重金属Pb的吸附过程可以用准二级动力学方程较好地解释,而且球形磁性活性炭经过1次再生后用于吸附土壤中Pb时,其吸附量达到2.56 mg/g,再生效率达72.11%,吸附效果良好。     

镁砂吸附剂的制备及其脱硫性能研究

以辽宁省大石桥市廉价镁砂为主原料,制备具有吸附功能的氧化镁吸附剂.活化后的吸附剂硫容较低,本文采用添加Na2CO3的方法提高吸附剂硫容.结果表明,采用饱和Na2CO3浸渍100 min,吸附剂硫容比原来提高两倍多.利用活化并添加助剂后的吸附剂进行脱硫试验,结果表明,当V(O2)∶V(SO2)=6～8、烟气温度为120～150 ℃、气体流量比V(H2O)∶V(O2)=2～4、SO2初始质量浓度为1 500～3 000 mg/m3、床层高度为5～7 cm时,脱硫效率达到92%.     

磷酸改性油茶壳活性炭吸附水中的氨氮研究

水体中氨氮的过量容易导致水体富营养化,对自然环境造成极大的破坏。以磷酸为活化剂,按照不同的实验条件改性制备了油茶壳活性炭,利用所制备的油茶壳活性炭对水体中的氨氮进行了吸附,探讨了活化温度、活化剂浓度、吸附时间、氨氮初始浓度对吸附效果的影响,并进行了吸附热力学和动力学分析。结果表明:活化温度550℃,磷酸质量浓度50%时制备的油茶壳活性炭吸附水中氨氮的效果最佳。吸附过程在6 h左右时达到平衡,符合准二级动力学模型。吸附过程符合Langmuir等温吸附模型,对氨氮的实际最大吸附量可达到12.51 mg/g。0.1 g的磷酸改性油茶壳活性炭对初始质量浓度为4 mg/L的氨氮废水中氨氮的去除率可以达到90.5%,吸附效果良好。     

颗粒活性炭的制备及其PSA分离CH4/N2的性能

以无烟煤为原料,煤焦油为黏结剂,采用预氧化-炭化-水蒸气活化法制备了变压吸附(PSA)分离甲烷/氮气(CH4/N2)用的颗粒活性炭( GAC).系统研究了炭化和活化制备条件对GAC的PSA分离效果的影响.结果表明,GAC分离CH4/N2是基于平衡分离效应.在炭化温度500～ 600℃,炭化时间1～3h,活化温度800～950℃,活化时间2～4h,水蒸气流速5～7 mL/min条件下制备的GAC能够将CH4/N2中的CH4体积分数较原料气提高20％以上;其中,在炭化温度600℃,炭化时间2.5h,活化温度900℃,活化时间2h,水蒸气流速5mL/min的条件下制备的GAC能够将CH4体积分数较原料气提高36.6％.     

催化活性炭纤维脱硫除汞性能试验研究

采用活化后的活性炭纤维(ACFs)作为吸附剂以脱除SO2和Hg.为增加其吸附效果,对ACFs进行氨水溶液活化处理,试验采用不同浓度氨水溶液(8%和13%),利用XPS和软件计算处理得到ACFs表面元素分析和基本官能团的变化,通过动态脱除SO2和Hg吸附试验,证明氨水溶液活化ACFs是一种增加SO2和Hg吸附的有效措施.试验表明,氨水浓度并非越浓越好,而是存在一个最佳值.     

Fenton-活性炭联合处理高浓度工业废水

实验采用Fenton氧化与活性炭吸附相结合的方法处理高浓度工业废水,考察了Fenton反应和活性炭吸附影响COD去除率的的最佳条件。结果表明,Fenton反应的最佳条件为H2O2∶COD=2,Fe2+∶H2O2=1∶4,反应pH=3,反应时间采用60 min。活性炭柱吸附最佳用量采用15 g活性炭吸附50mL Fenton反应后水样,两者结合COD最大去除率达到85.47%。     

油浸变压器排油注氮装置在500kV变电站的设计与应用

在分析500kV变电站主变压器消防系统的现状,比较3类消防系统优缺点的基础上,详细论述了主变排油注氮装置的结构组成、工作原理、参数计算、控制系统设计以及需要注意的事项等,为下一步排油注氮装置的推广应用打下基础.     

HAZOP结合What-if方法在某延迟焦化装置除焦中的应用

为克服传统危险与可操作性（HAZOP）定性分析方法在复杂操作、间歇作业等过程中使用的局限性,提出在传统HAZOP定性分析方法的基础上结合What-if（故障假设）方法,对人的不安全行为和操作规程不完备所导致的风险后果分析作出补充。详细说明其技术原理、工作流程等使用细节,系统阐述该方法与传统HAZOP定性分析方法的区别,并在某延迟焦化装置的除焦操作的风险分析中应用。经分析,识别出在“给水-泡焦”节点,有“操作规程错误”场景2项,“操作规程不具体”场景1项,不存在“操作人员未按操作规程执行”场景。研究结果表明:本文方法有效且具有较好效果,可以广泛应用于操作规程/作业指导书审查、作业过程隐患排查等方面,帮助企业开展操作层面的风险识别与管理,提升企业的生产安全水平。     

潞安矿区煤层渗透率的各向异性特征实验研究

为了研究原位煤体渗透性的各向异性特征,以山西潞安常村矿3号煤层圆柱试样为对象,利用TCQT-Ⅲ型低渗煤层气相驱替增产试验装置,对煤样进行加载,并以氮气注入压力2.0 MPa的条件下,分析垂直层理和平行层理2个方向的煤体变形和渗透率变化特征。实验结果表明:煤样在加载过程中,平行和垂直层理煤样渗透率均随着有效应力的增大而减小,平行层理方向的渗透率始终大于垂直层理方向,应力加载初期渗透率急剧下降,最后逐渐趋于平缓;径向应变的增加量与渗透率呈正相关性,且平行层理相关性大于垂直层理;沿平行层理方向的裂隙度大于沿垂直层理方向,沿垂直层理方向的应变量大于沿平行层理方向;应变增加量均随有效应力的增加而逐渐减小。研究结果可为煤层井网布置及优化提供参考。     

Nighttime pedestrian fatalities: A comprehensive examination of infrastructure,user, vehicle,and situational factors

Introduction: Pedestrian fatalities in the United States increased 45.5% between 2009 and 2017. More than 85% of those additional pedestrian fatalities occurred at night. Method: We examine Fatality Analysis Reporting System (FARS) data for fatal pedestrian crashes that occurred in the dark between 2002 and 2017. Within-variable and before/after examinations of crashes in terms of infrastructure, user, vehicle, and situational characteristics are performed with one-way analysis of variance (ANOVA) and two-sample t-tests. We model changes in crash characteristic proportions between 2002–2009 and 2010–2017 using linear regressions and test for autocorrelation with Breusch-Godfrey tests. Results: The increase in fatal nighttime pedestrian crashes is most strongly correlated with infrastructure factors: non-intersection unmarked locations (saw 80.8% of additional fatalities); 40–45 mph roads (54.6%); five-lane roads (40.7%); urban (99.7%); and arterials (81.1%). In addition, SUVs were involved in 39.7% of additional fatalities, overrepresenting their share of the fleet. Increased pedestrian alcohol and drug involvement warrant further investigation. The age of pedestrians killed increased more (18.1%) than the national average (3.2%). Conclusions: By identifying factors related to the increase in nighttime pedestrian fatalities, this work constitutes a vital first step in making our streets safer for pedestrians. Practical Applications: More research is needed to understand the efficacy of different solutions, but this paper provides guidance for such future research. Engineering solutions such as road diets or traffic calming may be used to improve identified infrastructure issues by reducing vehicle speeds and road widths. Rethinking vehicle design, especially high front profiles, may improve vehicle issues. However, the problems giving rise to these pedestrian fatalities are likely a result of not only engineering issues but also interrelated social and political factors. Solutions may be correspondingly comprehensive, employing non-linear, systems-based approaches such as Safe Systems.     

Footedness and Mounting—Short Review and Two Case Studies

Footedness is a personal quality like handedness. Footedness may be associated with moving ability during mounting, dismounting, and jumping movements. Occupational accidents have occurred during movement at different working levels, during the use of access and exit systems, and during the mounting of vehicles. Aging can also affect accident risk and body laterality. For example, falling accidents on stairs are common among the elderly. One reason for accidents may be that the structure of the access system or stair system is unsuitable for individual moving patterns depending partly on body laterality. Footedness and the way the feet are used may be contradictory to the demands of the moving situation, especially during uncommon or rapid situations. This contradiction may trigger disturbance during moving. The aims of this pilot study were (a) to review the literature briefly and (b) to describe the use of the dominant and nondominant foot by farmers and the elderly when mounting a tractor and stairs, respectively. The study also gives ideas for future studies based on both (a) and (b).     

AHP与GA-SVM耦合模型在滑坡预警中的应用*

为了减少滑坡造成的损失,提高滑坡预测的准确性,通过搭建灾害模拟平台获得滑坡的实验数据,在获得多组模拟实验数据后,分析各变量的特性。首先,通过层次分析(Analytic Hierarchy Process,AHP)算法,对滑坡进行危险度划分;然后,通过支持向量机(Support Vector Machine,SVM)建立模型,遗传算法(Genetic Algorithm,GA)再优化SVM参数,提出1种层次分析法与GA-SVM相耦合的模型。研究结果表明:AHP方法划分后的数据,通过GA与SVM结合建立的模型精度较好,实验预测结果与实际结果较为吻合,与单一SVM相比,精度更高,结果更好,更加适用于多变量的复杂非线性滑坡预警。     

Debunking the false dichotomy of leadership idealism and pragmatism: Critical evaluation and support of newer genre leadership theories

Leadership theories have shifted over the last few decades from a focus on managerial functions and economic leader–follower exchanges toward greater focus on the interpersonal dynamics occurring within the leadership process. Theories such as transformational, ethical, authentic, and other “newer genre” theories were created to address neglected topics such as leader vision and inspirational messages, transparency, emotional effects, morality, individualized attention, and intellectual stimulation. Critiques of these theories, however, have been raised. In this paper, we address five of those critiques and argue for the validity and practical effectiveness of the new genre theories. Further, we describe how newer genre leadership research should be viewed as a performative epistemology, entailing a process of co‐creation involving scholars and practitioners. Finally, from this view, we provide general ideas for leader development. Copyright © 2014 John Wiley & Sons, Ltd.     

Occupational Safety and Health in Finland

In Finland, occupational safety is the responsibility of the employer, while the occupational safety and health laws are enforced by the Labour Inspection Service, an organization of the state. The Labour Inspection is divided in 11 administrative districts, and it employs 360 professionals. They are mandated to carry out site visits without prearranged appointments to inspect safe work situations, working hours, construction safety, or any aspect of accident risks. The inspectors are also mandated to verify the existence of sufficient occupational health services as prescribed by the Occupational Health Services Act for all employees. The occupational health services are typically provided by enterprise-owned medical departments, by mutually owned health care centers, by private practitioners, or by municipal health care centers. The latter are required by law to provide all services as prescribed by the legislation to anyone who comes to the facility. This situation is prevalent in the countryside, where there are very few private caregiving centers. Declaring occupational accidents and disease cases is mandatory, and the Inspection districts examine all accidents to establish causes and consequences, and to initiate prosecution in case of criminal negligence. Labour Inspection Districts are also notified of the new occupational disease cases as they are declared to insurance companies. Insurance for occupational disease, accidents, and death is an obligation of the employer, although they can choose the insurance company. The medical confidentiality between the workers and their occupational health care providers is very strict. Official statistics are maintained by the state Statistics Finland organization, and they may be used, for example, for research purposes by scientific institutes like the Finnish Institute of Occupational Health. Construction industry accounts for 25% of all fatal accidents (120 cases per 1 million working hours), followed by mechanical, wood, metal, machinery, and pulp and paper industry (10% each of fatal accidents) with rates ranging from 100–160 cases per 1 million working hours. There are some 5,000 occupational disease cases per year (rate 22/10,000 employed). The major disease categories include repetitive strain injuries (1,300 cases), respiratory allergies (600 cases), occupational skin diseases (1,000 cases), and 900 cases of noise-caused hearing loss. In 1998, 589 cases of asbestos-related diseases were reported.     

森林地表火蔓延模拟方法及其计算机实现

进行了森林火蔓延的研究,对传统的经验公式和模型进行改进,明显发现改进的模型有更好的结果,用计算机巧妙准确地实现了模拟模型,在风力不是特别大,地形变化不是特别剧烈时,该模型有较高精度;并结合火蔓延的主要因素（气象因子、气候、地形等）,进行系统分析,写出算地,编制实现地表火蔓延的预测预报计算机系统软件。这对于有效的组织扑救、减少火灾损失、计算森林火灾的损失评估有重要意义。     

公路隧道火灾逃生疏散研究

以苍岭隧道为背景,首先采用经验计算理论和计算软件building EXODUS相结合的方式,从被困人员的安全疏散时间、高温烟气的影响、隧道横通道的利用率以及人员的疏散行为特性进行了研究。结果表明:中小规模火灾情况下的安全疏散时间控制在8 min之内,高温烟气影响不大,但横通道的利用率不平均,且人员疏散路线相对集中。然后对存在的逃生疏散问题提出针对性建议以及其他相关建议,旨在为更大程度降低事故的严重性和经济财产损失。