一种复合催化剂及其光催化降解煤矿瓦斯的性能研究

为提高催化剂光催化降解煤矿瓦斯效率,运用溶胶-凝胶浸渍过程将具有优异吸附性能的活性炭颗粒引入催化剂,制备了新型复合催化剂Ga2O3/AC。采用XRD、SEM、N2吸附等方法对新型复合催化剂的结构形貌及比表面积进行理化表征,验证了复合催化剂制备方法的可行性。同时以真空紫外灯为光源,进行光催化氧化降解瓦斯的模拟实验,对比考察Ga2O3、活性炭颗粒及复合催化剂的光催化活性。结果表明,相比单一Ga2O3,复合催化剂光照时间为180 min后对甲烷的降解率提高了13%,达到100%去除率。     

TiO_2/活性炭的微波制备及其对橙黄Ⅱ染料的光催化降解

采用微波辐射法制备TiO2/活性炭(TiO2/AC)复合光催化剂,并利用该催化剂对橙黄Ⅱ进行光催化降解。考察了乙醇与钛酸丁酯(TNB)的体积比,水、乙酸和活性炭的加入量,微波功率,微波辐射时间,煅烧温度等因素对TiO2/AC催化活性的影响,确定了制备TiO2/AC的最佳工艺条件以及TiO2/AC光催化降解橙黄Ⅱ的工艺条件。结果表明,制备TiO2/AC的最佳工艺条件为:乙醇与钛酸丁酯(TNB)体积比为8∶1(即乙醇24 mL,钛酸丁酯3 mL),水、乙酸和活性炭的加入量分别为0.8mL、0.6 mL和2 g,微波功率500 W,微波辐射时间1 min,煅烧温度500℃,煅烧时间为2 h。在TiO2/AC用量为0.3 g、反应时间为1 h、pH为3的条件下,25 mg/L橙黄Ⅱ溶液的降解率达95%以上。     

偶氮染料的光汗协同降解及其生成芳香胺的测定

以活性艳红X-3B为目标染料,选择AATCC标准人工汗液在光照条件下进行偶氮染料的降解反应.通过测定降解过程中紫外-可见吸收光谱的变化,表征了光汗协同对偶氮染料降解过程的影响.结果表明,光照与汗液对偶氮染料的降解脱色具有明显的协同作用.汗液中有机组分对偶氮染料的光汗协同降解起主要作用,但汗液中的无机盐组分对偶氮染料的降解脱色有一定的抑制作用.在相同辐照时间下,染料的降解脱色率随辐照强度的增加而增加,光强为2.68 mW/cm~2辐照240 min时,模拟水样中活性艳红X-3B的降解脱色率达35%以上.光汗协同降解反应过程中-lnA_t/A_0与t的关系符合一级动力学方程;反应的速率常数随光强的增加而增大.通过采用纤维膜保护液相微萃取和毛细管电泳联用的方法,实现了活性艳红X-3B光汗协同降解过程中生成苯胺的测定.     

TiO2悬浆体系光催化降解酸性红B动力学分析

采用TiO2悬浆体系, 以高硼紫外灯为光源, 考察了酸性红B 光催化降解中溶液初始质量浓度、催化剂投加量、无机盐、空气通入量、pH 值对光催化降解速率影响.用Langmuir-hinshelwood 方程描述酸性红B光催化动力学行为. 结果表明:初始质量浓度增加, 反应由一级向零级过渡; 催化剂投加量在0.5～2.5 g/L时, 30 mg/L酸性红B一级反应速率常数与投加量成线性关系; 5种溶解性无机盐对光催化降解酸性红B存在抑制作用, 阴离子影响大于阳离子; 通入空气影响动力学行为, 改变反应级数.本实验在pH 值为3时光催化降解效果最佳, 且酸性条件下比碱性下条件效果更好;TiO2表面吸附能力随pH 值增大而减弱,光催化过程控制步骤在酸性和碱性条件不同.     

三氯乙醛的光降解反应研究

研究了太阳光照下,水溶液中FeC l3-三氯乙醛的光化学反应速率,采用紫外分光光度计定时对含有不同浓度Fe（Ⅲ）的溶液进行实验测定,并根据三氯乙醛标准溶液曲线进行分析。实验结果表明,在波长为480nm的紫外光照射下：室内自然光下含有Fe（Ⅲ）和室外太阳光下不含Fe（Ⅲ）的三氯乙醛溶液中,三氯乙醛的浓度基本保持不变;但在室外太阳光下含有Fe（Ⅲ）的三氯乙醛溶液中,三氯乙醛的浓度随着Fe（Ⅲ）浓度的增加而减小。由此表明,Fe（Ⅲ）是三氯乙醛光化学反应的催化剂,FeC l3-三氯乙醛的光化学反应随着Fe（Ⅲ）浓度的增加而加快。     

铜铁共掺杂TiO2/膨润土光催化剂的制备及光催化性能

以溶胶-凝胶法、液相沉淀法和机械混合法制备了Cu-Fe双金属掺杂的TiO2/膨润土复合光催化剂,采用XRD、FTIR对其进行了结构表征,以紫外光和可见光催化降解直接天蓝染料废水为模型,考察了制备方法对催化剂光催化性能的影响。结果表明:各催化剂中均有锐钛矿型TiO2生成,且部分TiO2进入了膨润土的蒙脱石层间,改变了其层间的有序性,生成了Ti—O—Si键,实现了TiO2粒子与膨润土的复合。溶胶-凝胶法制备的催化剂中TiO2与膨润土的复合程度最高,Cu2+和Fe3+成功掺入了TiO2晶格,形成了复合半导体,拓宽了TiO2的光谱响应范围,使该催化剂表现出最优的光催化活性,并且该催化剂性能稳定,易于沉降分离,经高温活化再生后仍具有良好的催化活性,可重复多次使用,表现出良好的再生性能。     

矿井生产环境下光透过性实验研究

通过实验模拟巷道生产作业环境,分析了矿井生产环境下光照衰减的机理,研究了普通LED灯、金卤灯、荧光灯、头戴LED矿灯4种灯具在不同环境参数下的透射性,得出其在不同矿井因素（粉尘浓度、风速、相对湿度）下光的透过性影响规律,结果表明:在矿井中风速和相对湿度的增加均能降低光的透过率,相对湿度变化对光的透过率影响较大,且风速和相对湿度的增加对粉尘浓度有一定的积聚作用。研究结果为井下照明灯具的合理选用提供了依据。     

“Cu核-Cu2O壳”粒子可见光催化降解酚类废水的研究

以对硝基苯酚溶液为模拟废水,用自制的"Cu核-Cu2O壳"粒子对其进行光催化氧化试验,考察了光照时间、催化剂用量、对硝基苯酚的初始质量浓度、溶液的pH值和光源等对降解过程的影响。结果表明,对硝基苯酚溶液质量浓度为40 mg.L-1,催化剂投加量为2g.L-1,光照120min后降解率达到95%,降解反应符合一级反应动力学。与其他同类光催化剂相比,"Cu核-Cu2O壳"粒子具有较高的光催化活性,而且光催化过程中有氢氧自由基产生,对对硝基苯酚的降解较彻底。     

The photocatalytic degradation of carbamazepine and prediction by artificial neural networks

The three layer artificial neural network model was applied to predict the degradation efficiency for carbamazepine in photocatalytic oxidation under UV radiation. Titania–zirconia was employed as a catalyst for the photooxidation. The catalyst was prepared using titanium isopropoxide and zirconium oxychloride by sol–gel method and characterized by transmission electron microscopy and BET analysis. Different process parameters such as, initial concentration of carbamazepine, pH of the solution, catalyst concentration and time of UV irradiation were employed as the input to the artificial neural network model and the output of the network was degradation efficiency of carbamazepine. The multilayer feed-forward networks with the Levenberg–Marquardt (trainlm) backpropagation training algorithm was used for the network training. The smallest mean square error was obtained for three-layer network with ‘logsig’ transfer function and five neurons in the hidden layer gave optimal results. A comparison between the predicted values and selective experimental data of degradation efficiency showed a high correlation coefficient (R²) of 0.997.     

基于主成分分析法的危险货物运输企业安全评价

为更准确地评估危险货物运输企业安全等级以降低其运输风险,提出基于主成分分析法(PCA)的危险货物运输企业BP神经网络安全评价模型;在从人-机-物-环境-管理角度构建危险货物运输企业安全评价指标的基础上,分别利用该模型和其他3种模型对3家实例企业进行仿真评价和对比分析。结果表明,该模型的评价结果与期望值间的相对误差约为0.5%～1.2%,计算精度优于其他模型,且具有计算量小等特点。     

超声波及其联用技术处理有机污染物的研究进展

论述了超声波及其联用技术降解有机污染物的原理,影响因素和效果,国内外现状及发展趋势。指出超声波与其他方法联用可以大大提高有机物的降解效率,在处理难降解、有毒、有害有机污染物方面,特别是在净化环境,处理优先控制污染物方面有极大的应用前景。     

Red light violations at rural and suburban signalized intersections in Jordan

This case study investigated red light violations at rural and suburban signalized intersections in Jordan. Field observations were conducted at 15 signalized intersections located in different Jordanian regions: Amman, Irbid, and Zarqa. The results showed that, out of a total of 1,190 drivers who had a chance for violation, 153 (12.9%) drivers ran red lights. It was found that older drivers have less tendency for running red lights. Based on vehicle type, the analysis showed that truck drivers had the highest violation rate followed by small vehicles and then buses. The Y-shaped intersection had a higher percentage of violations as compared to the T- and cruciform-shaped intersections. The percentage of red light violations was found to be directly proportional to the subjects approach speed and inversely proportional to the conflicting traffic volumes.     

Method for Evaluating Germicidal Ultraviolet Inactivation of Biocontaminated Surfaces

Safety issues related to work-site conditions often deal with potential worker exposure to infectious airborne microorganisms due to their dissemination in indoor air and contamination of surfaces. Germicidal ultraviolet (GUV) radiation is used in health-care settings and other occupational environments for microbial inactivation. In this study, a new methodology for determining the efficiency of GUV microbial inactivation of surfaces was developed and evaluated. The method utilizes identical chambers in which test microorganisms are irradiated on agar surfaces at different humidity and irradiation intensity levels. The effects of GUV intensity and exposure time on microbial inactivation were examined for Micrococcus luteus and Serratia marcescens. It was found that at low humidity levels (20–25%) both organisms can be inactivated with at least 95% efficiency if the GUV intensity exceeds 50 μW/cm² for at least 3-5 min (corresponding to a dose of ~ 10 mJ/cm²). The radiation dose needed for effective inactivation of S. marcescens, as measured by a UV meter near the microbial sample, was found not to be affected by the humidity level, whereas that of M. luteus increased at higher humidities. The findings of this study can be used to determine sufficient GUV inactivation doses for occupational environments with various microbial contaminations.     

汽车乘务舱半物理环境模拟的甲醛光净化效果分析

汽车乘务舱半物理环境模拟系统,以测试室作为汽车乘务舱的模拟环境,采用平衡子系统作为甲醛污染物生成装置,用于研究在不同条件下甲醛污染物的光净化效果。实验结果表明:良好的通风条件可以改善甲醛的降解效果;甲醛初始浓度升高后虽然其降解效果有所下降,但是降解效果仍然可以达到80%以上;用改变电压来改变光强,9V和12V不同光强条件下,12V的效果好于9V;光照面积的增加可以明显地改善光催化降解的效果;玻璃和皮革作为载体时,皮革载体的降解效果要远好于玻璃载体。实验研究证明,光净化材料完全可以应用于汽车内环境中,且对甲醛空气污染物具有良好的净化效果。     

g-C3N4制备及其协同PDS可见光催化降解布洛芬的研究

以尿素为主要原料,采用热聚合法在不同条件下制备了光催化剂g-C3N4(石墨相碳化氮),通过改变尿素在马弗炉中加热的温度(350℃、400℃、450℃、500℃)和时间(0.5 h、1 h、1.5 h),得到不同烧结温度和时间的光催化剂,并对其进行X射线衍射(XRD)、扫描电子显微镜(SEM)、傅立叶红外光谱分析仪(FT-IR)、紫外可见漫反射光(UV-Vis)表征,并通过可见光光催化降解布洛芬试验,探究了制备温度、时间对g-C3N4光催化性能的影响;并在溶液中加入PDS(过硫酸钾),联合g-C3N4在可见光下光催化降解布洛芬。结果表明,当烧结温度为500℃、烧结时间为1.5 h时,制备的g-C3N4在可见光区有较强吸收且具有较大的比表面积,以致其表现出最佳的光催化性能;PDS的存在对布洛芬的降解有促进作用,且加快了g-C3N4对布洛芬的光催化降解,相比于纯g-C3N4,4 h内布洛芬的降解率由63%提升为90.5%。以异丙醇、甲醇、对苯醌、草酸钠、重铬酸钾、甲醇分别为羟基自由基(·OH)、·OH和硫酸根自由基(SO4^-·)、超氧自由基(·O2-)、空穴(h+)、电子(e^-)的捕获剂。通过对反应过程的活性物种鉴定,·OH、SO4^-·、h+、e^-均参与了布洛芬的光催化降解,其中h+在反应中的贡献率达到了82.9%,在降解布洛芬过程中起主导作用;在反应体系中添加PDS后,催化剂g-C3N4的荧光强度变小,即加入PDS能够有效降低g-C3N4的光生空穴与电子的复合率,提高g-C3N4的光催化性能。     

Sb2O5/TiO2催化超声降解甲基橙溶液

采用实验室合成的Sb2O5掺杂TiO2作为催化剂,研究各种因素对甲基橙的超声催化降解反应的影响.结果表明,在Sb2O5掺杂TiO2催化剂作用下,甲基橙的超声催化降解效果明显优于单独使用TiO2的情况.1.5%掺杂量的催化剂,用量在1.0～1.5 g/L之间,超声波频率25 kHz,输出功率1.0 W/cm2,pH为1.0～3.0时,初始浓度为20 mg/L的甲基橙水溶液,100 min左右基本可全部降解,COD去除率达到99.0%以上.Sb2O5掺杂TiO2催化超声降解有机污染物的方法具有很好的应用前景.     

Trends of hazardous material accidents (HMAs) during highway transportation from 2013 to 2018 in China

Statistical analysis of hazardous material accidents (HMAs) in China from 20013 to 2018 related to characteristics and consequences is discussed in this study, revealing different time volatility, spatial distribution and accident consequence features. Yearly, monthly, weekly and hourly levels of HMAs are analysed, and the corresponding factors are discussed. The trends of HMAs are affected by different factors, such as efforts toward safety-specific rectification by the government, holidays, five-day workweek systems and daily traffic peaks. The spatial distribution trends indicate that highway transportation of hazardous materials is mostly short-distance transport. The accidents that occurred on normal road sections account for 82.76% of the total HMAs during transportation. Leaking accidents caused by HMAs account for 79.35% of the total accidents. Countermeasures focusing on improving highway transportation safety for hazardous materials are recommended.     

矿用钢丝绳芯阻燃胶带与坑木燃烧特性的实验研究

介绍了锥形量热仪的基本原理和测试方法,在辐射能量35kW/m2的条件下对煤矿井下使用的钢丝绳阻燃胶带和两种木材的燃烧特性进行了实验研究,得到了3种材料的燃烧特征参数。实验结果表明:在产生的CO、释放的热量、生成的烟雾量方面,落叶松均少于果松,因此,落叶松的火灾危害性较小。钢丝绳芯阻燃胶带在产生的CO、释放的热量、生成的烟雾等方面明显大于两种木材,其火灾危害性比远远大于木材,因此,对钢丝绳芯阻燃胶带火灾应给予足够的重视。     

Investigative consequence analysis: A case study research of beirut explosion accident

Around 15:00 GMT on August 4th, an explosion occurred in the warehouse facility storing Ammonium Nitrate (AN) at Beirut port, Lebanon. The explosion resulted in more than 178 fatalities and injured more than 6500 people, and also left an estimated 300,000 people homeless and registered as an equivalent to a 3.3 magnitude earth quake. The accident was considered to be the largest of its kind and the most severe anthropological disaster of the decade, the financial loss the nation was subjected to post the explosion was estimated to be around $ 15 billion as informed by the governor. The storage conditions of ammonium nitrate at Beirut port is not definitively known to anyone, and there is no documentation provided so far from the authorities regarding the same. This work focuses on the investigation & consequence analysis of the explosion using TNT equivalent approach. The overpressure and the impulse obtained from TNT calculations are used in probit models to assess the damages caused on human beings and structures. The results obtained in this investigative approach are then utilized to provide an analytical inference relative to the damage proxy map reported by the advance rapid imaging analysis team from NASA. Also, this work examines the existing standards, fire safety measures and legal regulations for ammonium nitrate facilities in the region. AN explosion during storage like other fire and explosion accidents are definitely preventable owing to the technological advancements and developments to prevent or extinguish controllable fires. The significance of this work relates to the methods for calculation of consequences of explosion that are happening due to the storage of highly hazardous explosive materials in excessive quantities and insists the necessity of incorporating adequate safety measures while storing such reactive and hazardous materials.     

基于改进VRP模型的危险品配送路径优化及其求解研究

危险品道路运输高风险性,一直受到人们的广泛关注。危险品道路运输路径优化的研究,对于降低运输风险具有十分重要的意义。本文针对危险品运输配送过程中的路径优化问题,提出综合考虑道路运输的风险和费用两方面指标改进VRP模型路径优化目标,并设计遗传算法对改进模型进行了求解。最后通过实例进行了验证。结果表明：用遗传算法对改进VRP模型的求解结果与实际分析结果相符。因此,改进VRP模型及其遗传算法求解设计可以应用于危险品运输的路径优化分析。