柱状V2O5/AC催化剂低温选择性催化还原NO的研究

为了研究柱状活性焦负载V2O5选择性催化还原NO的性能,采用等体积浸渍法制备一系列柱状V2O5/AC催化剂,采用工业分析、元素分析、SEM、BET对催化剂进行表征.结果表明,柱状活性焦表面具有大量的孔隙结构,硝酸改性提高活性焦的氧含量、比表面积和微孔率.同时研究了V2O5负载量、反应温度、Q浓度、空速等因素对NO脱除率的影响.结果表明,在V2O5负载量为3％、反应温度150℃,O2体积分数为5％,空速2500 L/(M·h)时NO的脱除率可达61.89％.     

等离子体耦合Ce改性的复合型催化剂去除氮氧化物研究

为开发一种在大气污染物条件下可以复合催化氮氧化物的自制锯板脉冲放电反应器,同时为进一步制备高性能催化剂研究提供试验依据,采用脉冲放电耦合复合型催化剂对NOx进行去除试验.通过分步浸渍法制备一系列催化剂,研究脉冲放电耦合不同活性组分催化剂的脱硝效果,其中重点研究Fe掺杂及其不同掺杂量下制备的Fe/5A催化剂对NO转化率的影响.此外,进一步对Fe/5A催化剂掺杂适量Ce进行改性,进而制备复合型Ce-Fe/5A催化剂.通过XRD、SEM对催化剂进行相关性能表征.结果表明,Fe/5A催化剂活性在Cu/5 A,Mn/5 A,Cr/5A催化剂中最优,且当Fe掺杂的质量分数为8％时,单组分Fe/5A分子筛活性最好.掺杂一定量Ce后的Ce-Fe/5A催化剂表面更光滑,微孔增多,比表面积增大,被覆盖的不饱和金属配位点更易暴露以增加反应所需的活性点位,进而促进催化反应的有效进行,加强对NOx的脱除.当Ce掺杂的质量分数为3％时,Ce-Fe/5A催化剂对NO转化率效果最佳.由于脉冲放电可以改变催化剂的晶形和结构,因此Ce-Fe/5A催化剂耦合脉冲放电可以显著提高脱硝效率,其中添加还原性气体C2H2后效果更佳,且随着电压的增加,Ce-Fe/5A催化剂脱硝效果整体呈上升趋势.     

Ni-ACF催化H_2O_2氧化降解碱性品红废水

以活性炭纤维为载体,Ni2+,Mn2+,Zn2+和Fe2+的硝酸盐为活性组分,采用浸渍法制备了4种负载型催化剂,并以H2O2为氧化剂,碱性品红为目标污染物,用催化湿式氧化法,探讨了催化剂用量、H2O2投加量、染料初始浓度、反应溶液p H值、反应时间和催化剂重复使用等因素对碱性品红脱色效果的影响。结果表明,Ni-ACF较其它催化剂有较好的活性,染料的初始质量浓度为100 mg/L,Ni-ACF的用量为3.2 g/L、H2O2的投加量为20 m L/L、p H值为5.4(原液)时,反应4 h后碱性品红的脱色率达97.7%。催化剂重复使用活性良好,连续使用4次,脱色率仍可达62.5%。     

锰负载MCM-41分子筛催化臭氧氧化水中草酸的研究

通过水热法合成介孔分子筛MCM-41,采用等体积浸渍法制备了Mn负载MCM-41分子筛催化剂(Mn/MCM-41).采用小角X射线粉末衍射(XRD)、N2吸附-脱附等温线及透射电镜(TEM)等对催化剂的成分结构进行了表征.结果表明,Mn/MCM-41保持了纯硅MCM-41有序的介孔结构,锰元素以锰氧化物形式存在,比表面达到852m2/g.在草酸初始质量浓度为20 mg/L、O3投加量为100 mg/h、反应60 min、1％负载量、反应温度为35℃时,催化剂的加入显著改善了草酸的去除率,达到92.8％,是单独O3氧化的5.9倍.     

蜂窝状微量贵金属催化剂对几种典型VOCs的催化氧化性能

研制出了用于催化氧化废气中挥发性有机化合物(VOCs)的蜂窝状微量贵金属催化剂.用浸渍法制备催化剂Pt-Ce-La-Zr/Al2O3,并在自行设计的活性检测系统上,对用该催化剂净化含有苯、甲苯、乙醇、正己烷的模拟废气进行了研究,考察了空速、质量浓度等因素对催化剂活性的影响.实验结果表明,该催化剂对上述几种典型的VOCs气体都具有较低的起燃温度,其催化转化活性较好.     

SO2和H2O对Mn-Ce/TiO2催化剂低温SCR活性的影响

采用溶胶凝胶法制备Mn-Ce/TiO_2低温SCR催化剂并考察其活性,研究了SO_2和H_2O对Mn-Ce/TiO_2低温脱硝催化剂的影响,并运用XRD、BET、SEM和FT-IR对中毒前后的催化剂进行表征。结果表明,催化剂在无SO_2和H_2O条件下具有良好的脱硝性能,在140℃时NO_x去除率达到84%。但若向模拟烟气中加入SO_2和H_2O,则随其体积分数增大对催化剂活性产生明显抑制作用。当H_2O的体积分数为5%、SO_2为700×10-6时,反应4 h后,NO_x去除率降为53%。H_2O对催化剂的抑制作用随H_2O的除去而消除,H_2O主要通过与NO_x的竞争吸附来抑制催化剂的活性。低浓度的SO_2对催化剂活性影响较小,SO_2体积分数为100×10~(-6)时,稳定后NO_x去除率仍能维持在80%以上,但较高体积分数的SO_2引起的催化剂失活不可自行恢复。SO_2毒化作用主要是引起了硫酸铵盐覆盖催化剂的表面活性位,以及造成活性组分MnO_x的晶化,并破坏了MnO_x与TiO_2间的强相互作用。H_2O和SO_2共同存在时,H_2O可以弱化SO_2对催化剂的毒化作用,主要因为H_2O与SO_2的竞争吸附作用而使SO_2对催化剂活性的影响减弱。     

Fe对改性ACF负载锰铈复合氧化物低温NH_3选择性催化还原NO的影响

活性炭纤维(ACF)先经过硝酸处理形成ACFN,以锰氧化物为活性成分,Ce O2/ACFN为载体,采用浸渍法制备一系列不同物质的量比的Mn-Ce/ACFN催化剂。研究不同含量Fe的加入对Mn-Ce/ACFN的低温还原NO活性的影响。同时对比研究了Ce/ACFN、Mn-Ce/ACFN、Fe-Mn-Ce/ACFN净化NO的能力。利用热重分析(TG)实验、扫描电镜(SEM)和催化剂活性实验探讨了金属离子的分布、煅烧温度和不同载体对催化剂活性的影响。结果表明,Fe的引入使得Mn-Ce/ACFN的NH3-SCR活性显著提高,催化剂在140~280℃之间表现出良好的脱除NO的效果,最高的NO脱除效率达到91.3%。     

低温NH3-SCR脱硝催化剂研究进展

低温NH3-SCR脱除NOx是一种有潜力的烟气脱硝技术.综述了低温NH3-SCR脱硝催化剂的研究现状,重点介绍了锰基催化剂、钒基催化剂,以及其他金属氧化物基催化剂的研究状况,阐述了制备方法、催化剂载体,以及以不同金属改性对催化剂脱硝活性的影响.其中具备高比表面积、良好非晶态结构的低温NH3-SCR催化剂都有良好的低温脱硝活性.以CeO2改性锰(MnOx)基催化剂为例,探讨了低温NH3-SCR脱硝催化剂的脱硝机理.反应气体(NH3、NO和O2)在催化剂表面的吸附在低温NH3-SCR脱除NOx中发挥了重要作用.CeO2改性锰基催化剂催化NH3-SCR反应过程中涉及ER机理和LH机理,并且NH2与气态NO发生反应生成亚硝胺(NH2NO),进一步分解为N2和H2O是关键步骤.就燃煤烟气中水蒸气(H2O)和SO2在低温条件下对低温NH3-SCR脱硝催化剂的失活机制进行了阐述.烟气中的水蒸气与反应气体的竞争性吸附能够导致催化剂脱硝活性的降低.水蒸气(H2O)和SO2共同存在对低温NH3-SCR催化剂脱硝活性的影响表现为两者共同作用.烟气中水和SO2存在时生成的硫酸盐沉积在催化剂表面,并导致催化剂失活.     

负载型Mn/TiO_2太阳光催化氧化三价砷的研究

通过溶胶凝胶法制备了泡沫镍负载Mn/Ti O2催化剂,并将其应用于太阳光氧化三价砷的研究,考察了Mn/Ti O2的摩尔比、Ti O2负载次数、溶液p H值及菲涅尔透镜的使用对氧化三价砷速度的影响。实验结果表明,Mn/Ti O2的最佳摩尔比为1%,4 h后三价砷完全氧化为五价砷;Ti O2最佳的负载次数为2次;当溶液p H值为9时,催化剂催化氧化三价砷的速度最快,3 h三价砷完全氧化为五价砷;菲涅尔透镜的使用,显著地缩短催化剂氧化三价砷的时间;吸附剂-催化剂联用后,溶液体积20 L、三价砷质量浓度为100μg/L时,3.5 h后能将溶液中的砷全部去除。     

Cu-Ag/海泡石催化还原NO的研究

以天然海泡石为原料,对其进行酸改性并与活性氧化铝混合后作为催化剂载体,采用浸渍法制备了用于CO还原NO的Cu-Ag复合金属催化剂.对不同Ag负载量催化剂催化还原NO的活性进行了评价,考察了载体对催化剂催化活性的影响,用BET、XRD、SEM等对催化剂进行了表征.结果表明,当Ag负载量不超过5%时,复合金属催化剂性能好于单一金属催化剂;Ag负载量为2%时催化剂性能最好;采用海泡石-氧化铝混合物为载体的催化剂的孔径分布得到改善,对NO催化还原反应有更高的活性.     

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。     

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.     

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。     

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。     

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。     

一起有机过氧化物爆炸事故的调查和分析

阐述一起重大爆炸伤亡事故的现场调查和原因分析，介绍如何通过人证物证材料，用鱼刺图法找出可能引起事故的诸原因，逐项加以分析，将与人证或物证材料相矛盾的原因子以排除，最后剩下无法排除亦即能与人证物证相符的那个原因，就是事故的真正原因。笔者是这起事故调查专家组组长，取证和数据可靠。     

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.