旧工业建筑再生利用项目施工安全的评价及改进

针对旧工业建筑再生利用项目施工过程中存在诸多安全隐患的问题,首先,结合此类项目遗留工业垃圾冗杂、施工场地狭窄、部分构件拆换、大型机械使用受限的施工特点从4MTE角度构建施工安全评价指标体系。然后,在考虑指标赋权的主客观综合性与评价工作的未确知性后,建立了基于结构熵权法与未确知测度理论的旧工业建筑再生利用项目施工安全评价模型,并通过工程实例验证该模型,得出的评价结果与实际情况相符。最后,结合未确知测度单因素指标测度函数的特点,提出了施工安全管理改进策略的制定方法。     

Bicycle helmet effectiveness is not overstated

Objective: The objective of this study was to discuss the challenges in estimating bicycle helmet effectiveness from case–control studies of injured cyclists and to estimate helmet effectiveness from cases and available exposure data.

Methods: Data were extracted from studies of cyclists in Seattle; Victoria and New South Wales, Australia; and The Netherlands. Estimates of helmet use were used as exposure to compute relative risks for Seattle and Victorian data. Cycling distance data are routinely collected in The Netherlands; however, these data cannot be disaggregated by helmet use, which makes it unsuitable for estimating helmet effectiveness. Alternative controls were identified from larger cohorts for the Seattle and New South Wales cases.

Results: Estimates of helmet effectiveness were similar from odds ratios (ORs) using hospital controls or from relative risks (RRs) using helmet use estimates (Seattle: OR = 0.339, RR = 0.444; Victoria: OR = 0.500, RR = 0.353). Additionally, the odds ratios using hospital controls were similar when controls were taken from a larger cohort for head injury of any severity (Seattle: OR = 0.250, alt OR = 0.257; NSW: OR = 0.446, alt OR = 0.411) and for serious head injury (Seattle: OR = 0.135, alt OR = 0.139; NSW: OR = 0.335, alt OR = 0.308). Although relevant exposure data were unavailable for The Netherlands, the odds ratio for helmet effectiveness of those using racing, mountain, or hybrid bikes was similar to other estimates (OR = 0.371).

Conclusions: Despite potential weaknesses with case–control study designs, the best available evidence suggests that helmet use is an effective measure of reducing cycling head injury.     

Road accident fatality risks for “vulnerable” versus “protected” road users in northern Ghana

Background: Road traffic injuries (RTIs) are a serious epidemic that claims more than a million lives across the globe each year. The burden of RTIs is particularly pronounced in Africa and other low- and middle-income countries. The unfavorable disparity of the burden of road trauma in the world is largely attributable to unsafe vehicles, lack of appropriate road infrastructure, and the predominance of vulnerable road users (VRUs) in developing countries. However, little research exists in northern Ghana to highlight the scale and risk of death among road users.

Objective: The objective of this research was to establish the relative risk of death among road users in northern Ghana.

Methods: Crash data from police reports between 2007 and 2011 were analyzed for the Upper Regions of Ghana. Conditional probabilities and multivariable logistic regression techniques were used to report proportions and adjusted odds ratios (AORs), respectively.

Results: Generally, crashes in northern Ghana were extremely severe; that is, 35% of all injury related collisions were fatal. The proportion of fatal casualties ranged between 21% among victims of sideswipe collisions and 41% among pedestrians and victims of rear-end collisions. Though males were 6 times more likely to die than females overall, females were more likely to die as pedestrians (90% of all female casualty deaths) and males were more likely to die as riders/drivers (78% of all male casualty deaths). Pedestrians were 3 times more likely to die (odds ratio [OR] = 3.1; 95% confidence interval [CI], 2.4 to 4.1) compared with drivers/riders. Compared with drivers, the odds of death among cyclists was about 4 times higher (AOR = 3.6; 95% CI, 2.3 to 5.6) and about 2 times higher among motorcyclists (AOR = 1.6; 95% CI, 1.2 to 2.2). Compared with casualties aged between 30 and 59 years, children under 10 years and those aged 60 years and above were independently 2 times more likely to die in traffic collisions.

Conclusion: Provision of requisite road infrastructure is vital for the safety of VRUs in northern Ghana. Cycle paths and lanes (for cyclists) as well as sidewalks (for pedestrians) in particular will separate VRUs from motorists and improve their safety. Enforcement of traffic laws particularly regarding helmet use, speeding, and alcohol use will be beneficial. Introduction of the demerit points system in the enforcement of traffic regulations may have significant deterrent effects on road users who have the penchant for violating traffic regulations. Road safety education is also required to create responsible road users.     

中国水污染防治40年回顾与展望

改革开放40多年来,我国水污染防治工作取得巨大成效。本文通过回顾我国水污染防治发展历程和总结不同阶段我国流域水污染防治工作特点,提出了面向2035年水生态环境保护的管理建议,以期为2035年美丽中国水环境建设提供参考。     

Comparative study on pyrolysis of bamboo in microwave pyrolysis-reforming reaction by binary compound impregnation and chemical liquid deposition modified HZSM-5

The deactivation of catalyst is a significant reason for its limited application during the catalytic fast pyrolysis (CFP) process. To reduce the coke formation, binary compound impregnation (BCI) and chemical liquid deposition (CLD) were used to modify HZSM-5 catalysts. At the same time, the self-designed microwave reactor separated the pyrolysis of bamboo and catalytic upgrading of primary vapor, which made the catalytic effect more thorough. Experimental results indicated that CLD used TiO₂ deposition to cover external acid sites, while BCI by phosphorus-nickel could cover and partly destroy superficial acid sites through two different ways. Within the scope of the loaded amount studied, the yield of aromatic hydrocarbons in the oil phase increased at first and then decreased, while the coke formation reduced continuously. BTX (benzene, toluene and xylene), the most valuable product in bio-oil, drastically increased by 39.1% and 22.6% respectively over the CLD and BCI modified catalysts. Considering the catalytic performance as well as cost, CLD over HZSM-5 has more advantages in the CFP process to upgrade bio-oil.     

面向生态环境保护的长江上游老旧码头布局功能优化

针对长江上游部分港口码头环保基础设施、技术、工艺较为落后,难以满足日益趋严的环保要求的问题,以重庆长寿港区为例,按照“关键生态环境问题识别—码头布局功能优化—生态风险分析”的思路,开展了长江上游老旧码头布局功能优化研究.结果表明:①现状中存在的关键生态环境问题:煤炭砂石等高污染码头作业区分布散、规模小且同质化经营,导致岸线集约化利用程度低;铁水联运条件未充分利用,导致公路转运对城区环境压力凸显.②基于产业规模与泊位建设供需分析—泊位布置—作业区布置的技术路线,通过优化临港产业布局,关停并转作业区6个,恢复岸线483 m,规划生产性泊位由56个减至46个,规划利用岸线由9 565 m减至8 225 m,促进码头作业规模化、产业结构合理化、岸线利用集约化.③根据铁路物流量测算,规划提升铁路运能,预测2035年铁路货运分担率将达13%、水运分担率将达29%、公路运输量将逐年下降.④布局功能优化后,港口码头与铁公水联运的生态环境相对风险值大幅降低,证实了岸线集约利用和提高铁水联用运输结构比例可降低交通运输对区域生态环境的风险压力.研究显示,面向绿色可持续发展的产业总体布局与面向高效低污染的铁水联运优化,是长江上游老旧码头提升发展的有效途径.      

Surface characterization of metal oxides-supported activated carbon fiber catalysts for simultaneous catalytic hydrolysis of carbonyl sulfide and carbon disulfide

The sol–gel method was used to synthesize a series of metal oxides-supported activated carbon fiber (ACF) and the simultaneous catalytic hydrolysis activity of carbonyl sulfide (COS) and carbon disulfide (CS₂) at relatively low temperatures of 60°C was tested. The effects of preparation conditions on the catalyst properties were investigated, including the kinds and amount of metal oxides and calcination temperatures. The activity tests indicated that catalysts with 5 wt.% Ni after calcining at 400°C (Ni(5)/ACF(400)) had the best performance for the simultaneous catalytic hydrolysis of COS and CS₂. The surface and structure properties of prepared ACF were characterized by scanning electron microscope-energy disperse spectroscopy (SEM-EDS), Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), carbon dioxide-temperature programmed desorption (CO₂-TPD) and diffuse reflectance Fourier transform infrared reflection (DRFTIR). And the metal cation defects were researched by electron paramagnetic resonance (EPR) method. The characterization results showed that the supporting of Ni on the ACF made the ACF catalyst show alkaline and increased the specific surface area and the number of micropores, then improved catalytic hydrolysis activity. The DRFTIR results revealed that -OH species could facilitate the hydrolysis of COS and CS₂; -COO and -C–O species could facilitate the oxidation of catalytic hydrolysate H₂S. And the EPR results showed that high calcination temperature conditions provide more active reaction center for the COS and CS₂ adsorption.     

瘤胃微生物强化醋糟厌氧消化及其机制

针对醋糟中木质纤维素利用效率低的问题,通过接种瘤胃微生物可强化木质纤维素水解.采用逐步提升体系有机负荷的方式,考察瘤胃微生物生物强化对醋糟厌氧消化性能的提升效果,并运用绝对定量实时聚合酶链锁反应（Q-PCR）技术探究其微生物学强化机制.结果表明:长期连续运行成功塑造了高效的木质纤维素瘤胃强化体系.该体系的最高有机负荷达8.90 g/（L·d）（以VS计）,是强化前的1.53倍,该有机负荷下半纤维素和纤维素降解率分别达73.9%和40.1%,单位质量底物沼气和甲烷产量相应地分别达到451和261 mL/g（以VS计）,半纤维素和纤维素较高的降解率是该体系维持高产气性能的主要原因.生物相机制研究表明,瘤胃微生物强化体系中与木质纤维素水解密切相关的GH5（糖苷水解酶家族5）水解菌逐步富集,其基因拷贝数从初始的964×1010 copies/g升至最高有机负荷下的6.83×1011 copies/g,这是底物在高有机负荷下仍能被高效生物转化的根本原因.研究显示,瘤胃微生物的介入可有效强化体系底物的降解能力,促进醋糟产甲烷性能的提升.      

高晶度Mn-Fe LDH催化剂活化过一硫酸盐降解偶氮染料RBK5

采用改进的共沉淀结合水热法制备高晶度锰铁层状双金属氢氧化物作为催化剂,用于高效活化过一硫酸盐(PMS)降解活性黑5(RBK5).通过X射线粉末衍射仪(XRD)、扫描电子显微镜(SEM)、X射线能谱分析(EDS)、傅里叶变换红外光谱仪(FTIR)以及X射线光电子能谱(XPS)对材料进行表征,证明成功合成了结晶度高、层状结构突出的Mn-Fe LDH.同时探究了锰铁量比,催化剂投加量,PMS浓度和初始pH值等因素对RBK5的吸附效果、催化降解及反应动力学的影响.结果表明,高晶度Mn-Fe LDH催化剂具有良好的吸附能力和高效的催化效率,在n(Mn)/n(Fe)比为1∶1,催化剂投加量为0.2 g·L~(-1),PMS浓度为1 mmol·L~(-1),初始pH为7时,RBK5(20 mg·L~(-1))在90 min内降解率可达86%,整个反应过程符合拟一级动力学(R~20.9).自由基猝灭实验表明,Mn-Fe LDH/PMS体系降解RBK5为SO~-_4·和·OH两种活性自由基共同作用的结果.反应前后催化剂的XPS分析表明Mn和Fe存在协同作用,Mn-Fe LDH的Mn(Ⅱ)和Fe(Ⅲ)与层间的CO~(2-)_3电荷平衡,使其层状结构稳定,从而促进了层状表面Mn和Fe的协同作用,提高了Mn-Fe LDH对PMS的活化效率.三维荧光光谱(3D-EEM)和UV-Vis扫描光谱分析初步探讨了RBK5的降解过程.     

NZVI/Na2S2O8/超声复合法降解污染土壤PCB-29

多氯联苯（polychlorinated biphenyls,PCBs）是一类具有高毒性、难降解的有机化合物,为了研发土壤中多氯联苯（PCBs）污染物高效处理技术,本研究采用PCBs中的2,4,5-三氯联苯（PCB-29）作为研究对象,以纳米零价铁（NZVI）活化Na₂S₂O₈,再辅以超声氧化对土壤中PCB-29进行降解试验,结果表明,NZVI/Na₂S₂O₈/超声复合法对污染土壤中PCB-29具有很好的去除效果,降解反应时间为1h时,去除率最高可达86.37%;NZVI/Na₂S₂O₈/超声复合法对PCB-29最佳降解条件为土壤初始pH值为5.0,Na₂S₂O₈浓度为12mmol/L,Na₂S₂O₈/NZVI物质的量比1：1.