周期换向电凝聚法处理染料废水的脱色机理研究

利用金属铝或铁做电极电凝聚法处理印染的废水过程中,存在阳极板易钝化而影响脱色效果、处理效率低下等问题.理论分析表明,采用周期换向电源和金属铁、铝分别作为两极,电化学法处理染料废水,可以有效防止电极钝化,提高处理效率.以活性黑KN-B模拟染料废水为例,采用自行设计的周期换向电源,铝板和铁板为反应电极,对周期换向电源电凝聚法处理染料废水的脱色机理进行了研究.结果表明:该方法对活性黑KN-B模拟染料废水的脱色率在99%以上,起脱色作用的主要有电解还原氧化、气浮及金属离子絮凝等过程,且周期换向电源能有效防止采用铝铁电极电化学处理染料废水过程中出现的阳极钝化现象.     

预处理青霉菌（Penicilium sp.）吸附活性艳红的研究

为研究生物吸附剂青霉菌(Penicilium sp.)对染料活性艳红X-3B的吸附性能,考察了菌体预处理方法、溶液初始pH值、盐度等因素对生物吸附的影响,并对吸附机理进行了探讨.结果表明,在选取的预处理方法中,酸处理的菌体吸附效果要优于碱和盐处理.在染料质量浓度为50 mg/L时,经硝酸处理的菌体吸附效果最好,比原菌体的吸附效果提高了40%以上.试验发现改变硝酸的浓度对菌体吸附效果影响不大.硝酸处理菌体的时间越长,达到吸附平衡所需的时间越短.低浓度的NaCl有利于菌体对染料的吸附.体系中50 mg/L的Pb2 或Zn2 对吸附活性艳红有一定的促进作用.对硝酸处理菌体过程中的金属离子和pH值分析表明,菌体吸附了大量的H ,同时有K 和Mg2 释放.对菌体进行红外光谱分析表明,预处理的菌体在酰胺Ⅰ、酰胺Ⅱ和酰胺Ⅲ吸附峰处明显比原菌体增强,表明菌体主要吸附位点可能是氨基,在酸性条件下对染料以静电吸附为主.     

锯末吸附处理染料废水的初步研究

以锯末为吸附材料,研究锯末吸附染料废水中的染料从而对废水进行脱色处理,为锯末这一废弃物的综合利用找到新的途径,为污水处理提供了一定的实验和方法基础。     

铝铁电极换向电源电凝聚法处理活性黑KN-B染料废水的研究

针对普通电凝聚技术处理染料废水过程中采用单向电流易造成阳极损耗增加处理成本的缺点,对传统的电凝聚法进行改进,采用换向电源、铝铁分别作为两极的新型电化学反应器,以色度和CODCr去除率作为指标,利用电凝聚技术处理活性黑KN-B染料模拟废水.通过周期性改变电解电流方向,实现金属铝和铁电极均可溶解,同时产生具有絮凝作用的金属离子,并减缓金属阳极的损耗速度.结果表明,该方法对活性黑KN-B模拟染料废水具有较好的处理效果.其最佳处理条件为: 电解时间30 min,电解电压10 V,电源换向周期10 s,染料质量浓度100～300 mg/L,电解质(Na2SO4)浓度0.01 mol/L,搅拌速度1 000 r/min,极板间距1.0 cm,pH=5～9.在此条件下,色度去除率可达99%以上,CODCr去除率可达50.0%以上.电解时间、电解电压、换向周期、染料质量浓度、电解质(Na2SO4)浓度、搅拌速度、极板间距、pH值等因素对色度和CODCr去除率均有一定程度影响.色度主要是由于活性黑KN-B染料发生化学反应,染料分子中的发色基团-N=N-键被打开,生成苯环衍生物而得到去除;CODCr的去除则主要是絮凝和气浮现象共同作用的结果.扫面电镜测试(SEM)结果表明,该方法可以有效减缓阳极损耗过程.     

循环微电解法处理染料废水的研究

采用循环微电解法处理染料废水,测量水样的COD值、pH值、色度等指标.结果表明,色度去除率可高达95%,且脱色迅速;COD值的去除率约为60%.使用循环微电解法可以对染料废水进行预处理,很大程度上提高废水的可生化性,为染料废水的进一步生化处理创造条件.     

不同添加剂对Cd污染土壤植物修复的试验研究

研究了4种添加剂对修复镉(Cd)污染土壤的影响.除氯化钙能抑制植株对Cd的吸收外,十二烷基苯磺酸钠、柠檬酸、酒石酸均能促进植株对Cd的吸收.壤土、粘土、砂土中植株生物量的最高值都对应20 mmol/kg氯化钙处理后的植株,其生物量分别比对照样本增加了10％、8％和7％;生物量最低值则是20mmol/kg酒石酸处理后的植株,其生物量分别减少了52％、68％和56％.使用4种添加剂处理后,雪里蕻地下部分的Cd含量远大于地上部分.施加酒石酸和柠檬酸可显著提高Cd向地上部分的迁移能力,十二烷基苯磺酸钠对Cd迁移能力的影响较小,施加氯化钙后Cd的迁移系数下降较快.     

即时合成层状氢氧化物去除直接大红染料废水

初步研究了即时合成层状氢氧化物去除直接大红染料废水的实验方法、影响因素和去除机理.实验结果表明,处理直接大红染料的最佳条件为:染料初始质量浓度为300 mg/L,pH值为10,Mg/Al摩尔比为3:1,在此条件下,染料去除率可达100％,Mg2+的利用率可达73％,Al3+的利用率可达94％.其去除机理主要是:Mg2+、Al3+水解共沉淀形成LDH,染料阴离子优先进入LDH结构层间平衡结构电荷,从而使染料以LDH沉淀形式被去除.     

煤渣/PAC复合混凝剂对橙黄Ⅱ废水的脱色处理

采用煤渣与PAC复合混凝剂对橙黄Ⅱ模拟废水进行脱色处理,考察了煤渣粒径、pH值、煤渣投加量和PAC用量对处理效果的影响,探讨了复合混凝剂的脱色机理.结果表明,采用煤渣/PAC复合混凝剂处理染料废水可获得良好的脱色效果,出水色度和浊度均可达到国家排放标准.主要脱色机理为煤渣对染料分子的吸附,PAC可促进细小煤渣颗粒结成絮体,强化脱色和去浊效果.     

动态铁屑粉煤灰内电解法处理染料废水的研究

研究了内电解法动态处理3种染料废水的工艺条件,如反应时间、pH值、铁屑投加量、铁屑粉煤灰比例等.在最佳工艺条件下,动态内电解法处理混合染料废水,色度去除达95%,CODCr去除率也达70%.并讨论了铁屑-粉煤灰内电解法处理染料废水的机理.     

铁阳极电凝聚法处理活性黑KN-B染料废水能耗分析

对铁阳极电凝聚处理活性黑KN-B染料废水过程中影响电能消耗的因素进行了分析.结果表明:电流密度、染料废水初始pH、染料废水温度、染料废水初始浓度和电解质浓度对能耗均有明显影响,并得到能耗与电流密度、染料废水初始浓度、氯化钠电解质浓度之间指数的曲线方程.脱色效率受温度的影响较小,电流效率受电解质浓度以及染料废水初始的pH影响较大;对于质量浓度为50 mg/L的活性黑KN-B染料废水,在电流强度为20.83 A/m2,电解温度为25℃,硫酸钠浓度为0.01 mol/L,pH为7.13的条件下,染料废水脱色率达93%,染料脱色电能消耗为4.14(kW-h)/kg,电流效率为105.29%.     

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。