镇江市典型产业园区青菜中重金属特征分析

于2017年1月采集镇江市典型产业园区7个不同点位的青菜及青菜田土壤样品进行重金属含量分析,结果表明,园区青菜中Cr、Cu、Zn元素均值小于食品卫生标准限值,Ni、Cd和Pb元素的均值介于食品卫生标准限值的临界;青菜中Ni、Cd、Pb 3种重金属处于轻度污染状态,Cr、Cu和Zn 3种重金属为无污染状态;青菜田土壤中重金属含量仅Cr和Cd在个别点超过《土壤环境质量农用地土壤污染风险管控标准》(GB 15618—2018)标准限值,其余各点位6种重金属元素均低于标准限值。     

Enhanced performance of alkali-modified Bi2WO6/Bi0.15Ti0.85O2 toward photocatalytic oxidation of HCHO under visible light

Environmental Science and Pollution Research - Photocatalytic oxidation of formaldehyde (HCHO) is considered as one of the promising ways to resolve indoor air HCHO pollution. TiO2 has been well...     

β射线衰减法与微量振荡天平法测定PM 10的比较

对现场监测环境空气中PM10 的两种测定方法—β射线衰减法和微量振荡天平法的测量作了对比实验。实验表明 ,两种测定方法的结果具有一致性、相关性和可比性 ,能用回归直线方程来描述两者之间的关系。β射线衰减法的测定结果平均高于微量振荡天平法 15 8% ,它们之间平均偏差为 7 5 %。微量振荡天平法在现场测定中受干扰物和不确定因素的影响较少 ,其测量准确性优于 β射线衰减法。两种监测仪的运行费用大致相同 ,维护量和故障率均 较低     

Computational modeling and analysis of thoracolumbar spine fractures in frontal crash reconstruction

Abstract

Objective: This study aimed to reconstruct 11 motor vehicle crashes (6 with thoracolumbar fractures and 5 without thoracolumbar fractures) and analyze the fracture mechanism, fracture predictors, and associated parameters affecting thoracolumbar spine response.

Methods: Eleven frontal crashes were reconstructed with a finite element simplified vehicle model (SVM). The SVM was tuned to each case vehicle and the Total HUman Model for Safety (THUMS) Ver. 4.01 was scaled and positioned in a baseline configuration to mimic the documented precrash driver posture. The event data recorder crash pulse was applied as a boundary condition. For the 6 thoracolumbar fracture cases, 120 simulations to quantify uncertainty and response variation were performed using a Latin hypercube design of experiments (DOE) to vary seat track position, seatback angle, steering column angle, steering column position, and D-ring height. Vertebral loads and bending moments were analyzed, and lumbar spine indices (unadjusted and age-adjusted) were developed to quantify the combined loading effect. Maximum principal strain and stress data were collected in the vertebral cortical and trabecular bone. DOE data were fit to regression models to examine occupant positioning and thoracolumbar response correlations.

Results: Of the 11 cases, both the vertebral compression force and bending moment progressively increased from superior to inferior vertebrae. Two thoracic spine fracture cases had higher average compression force and bending moment across all thoracic vertebral levels, compared to 9 cases without thoracic spine fractures (force: 1,200.6 vs. 640.8 N; moment: 13.7 vs. 9.2?Nm). Though there was no apparent difference in bending moment at the L1–L2 vertebrae, lumbar fracture cases exhibited higher vertebral bending moments in L3–L4 (fracture/nonfracture: 45.7 vs. 33.8?Nm). The unadjusted lumbar spine index correctly predicted thoracolumbar fracture occurrence for 9 of the 11 cases (sensitivity?=?1.0; specificity?=?0.6). The age-adjusted lumbar spine index correctly predicted thoracolumbar fracture occurrence for 10 of the 11 cases (sensitivity?=?1.0; specificity?=?0.8). The age-adjusted principal stress in the trabecular bone was an excellent indicator of fracture occurrence (sensitivity?=?1.0; specificity?=?1.0). A rearward seat track position and reclined seatback increased the thoracic spine bending moment by 111–329%. A more reclined seatback increased the lumbar force and bending moment by 16–165% and 67–172%, respectively.

Conclusions: This study provided a computational framework for assessing thoracolumbar fractures and also quantified the effect of precrash driver posture on thoracolumbar response. Results aid in the evaluation of motor vehicle crash–induced vertebral fractures and the understanding of factors contributing to fracture risk.     

Excellent performance of Cu-Mn/Ti-sepiolite catalysts for low-temperature CO oxidation

The Ti-modified sepiolite (Ti-Sep)-supported Mn-Cu mixed oxide (yMn5Cu/Ti-Sep) catalysts were synthesized using the co-precipitation method. The materials were characterized by the X-ray diffraction scanning electron microscope, N₂ adsorption-desorption, H₂-TPR, O₂-TPD, and XPS techniques, and their catalytic activities for CO oxidation were evaluated. It was found that the catalytic activities of yMn5Cu/Ti-Sep were higher than those of 5Cu/Ti-Sep and 30Mn/Ti-Sep, and the Mn/Cu molar ratio had a distinct influence on catalytic activity of the sample. Among the yMn5Cu/Ti- Sep samples, the 30Mn5Cu/Ti-Sep catalyst showed the best activity (which also outperformed the 30Mn5Cu/Sep catalyst), giving the highest reaction rate of 0.875 × 10^–3 mmol·g^–1·s^–1 and the lowest T _50% and T _100% of 56°C and 86°C, respectively. Moreover, the 30Mn5Cu/Ti-Sep possessed the best low-temperature reducibility, the lowest O₂ desorption temperature, and the highest surface Mn³⁺/Mn⁴⁺ atomic ratio. It is concluded that factors, such as the strong interaction between the copper or manganese oxides and the Ti-Sep support, good low-temperature reducibility, and good mobility of chemisorbed oxygen species, were responsible for the excellent catalytic activity of 30Mn5Cu/Ti-Sep.

Open image in new window

     

美国化学物质数据报告制度的经验和启示

回顾了美国《有毒物质控制法》(TSCA)中现有化学物质数据报告(CDR)制度的历史背景。介绍了CDR制度的基本内容、数据质量保证、主要修订情况,以及2012年CDR上报的化学物质数据信息汇总分析情况。针对2016年开展的新一轮CDR数据报告,总结了其最新的变化和具体要求。从建立化学物质信息收集制度、对现有化学物质进行分级管理、重点关注化学物质用途划分和归类,以及建立数据库和信息系统等4个方面,探讨了CDR制度对我国化学品环境管理的启示。     

典型挥发性有机化合物在气体采样罐中的存储稳定性

选取了6种有代表性的挥发性有机化合物（VOCs）,异丙醇、二氯甲烷、乙酸乙烯酯、正己烷、苯和四氯化碳,实测了这些VOCs在气体采样罐（SUMMA罐）中的存储稳定性。结果表明：苯、正己烷和二氯甲烷在采样罐中均较稳定,其含量在84 d的存储期内基本无变化;乙酸乙烯酯在6个VOCs中最不稳定,在普通和惰性采样罐中含量均明显下降;异丙醇和四氯化碳的稳定性与采样罐的类型有关,在普通采样罐内含量下降明显,而在惰性采样罐内则相对稳定。实际监测工作中,为提高VOCs分析的准确性,如目标分析物有含氧类（醇,酮,酯等）或含卤素类VOCs,则采样后需尽快分析,同时尽量选择惰性采样罐为采样容器。     

可溶态汞治理新方法的研究

采用自制的ＴＣ型钛系催化剂（ＴｉＯ２／ＣｏＯ）,对于含汞为５０ｍｇ／Ｌ的试液,经一次性处理,并控制试液ｐＨ＝７．５,搅拌２ｍｉｎ,可使试液中汞含量降至０．０００４４ｍｇ／Ｌ,汞去除率达９９．９９％以上。催化剂可重复使用,并可用ＨＣｌ溶液再生。方法简便、快速。对于５种工厂废水试验结果令人满意。     

ZE-1号印染废水脱色菌群结构与功能的研究

印染废水是水体的主要工业污染源之一。研究表明,利用微生物对印染废水进行脱色处理是一条可行的途径。浙江省环保科研所曾选育得到一组脱色性能较好,具有应用前景的混合菌群。命名为ZE-1号脱色菌群。     

溶剂萃取法提取电镀污泥氨浸出渣中的金属资源

研究硫酸浸出Ｐ５０７－煤油－硫酸体系萃取分离铁,钠皂－Ｐ２０４－煤油－硫酸体系共萃铬、铝、反萃取分离铬、铝工艺回收电镀污染氨浸渣中的金属。通过优化实验,确定了全流程的最佳工艺参数。结果表明,铁铬渣中的金属铬、铝和铁均可以高纯度盐类形式回收,可作为化学试剂使用,回收率达９５％以上。