改性成都粘土预处理垃圾渗滤液的研究

文章采用十六烷基三甲基溴化铵(HDTMA)、丙烯酰胺(AM)和聚合氯化铝(PAC)3种改性剂分别对成都粘土进行改性,将改性粘土用于垃圾渗滤液处理,比较不同改性粘土对氨氮和COD的吸附性能,并通过X射线衍射、红外光谱、热分析技术对改性粘土进行表征,分析作用机理;研究表明,粘土经过改性后,3种改性粘土的底面间距分别增大0.7533、0.3496、0.1929nm,对垃圾渗滤液中氨氮和COD去除效果关系为:HDTMA改性土>AM改性土>PAC改性土>原土,HDTMA改性土为最优改性土。改性粘土预处理渗滤液方法是可行的,HDTMA改性土是最优改性土,对氨氮去除率达到48.68%,COD去除率达到32.27%,控制条件为:投加量为100g,pH=7,转速为200 r/min(50min),静置时间6h。     

GIS和MATLAB在泥石流防治工程流量计算中的应用研究—以北川县苏保河为例

根据1976年松潘地震的经验,可预见未来较长时间内,"5-12"地震灾区泥石流防治的工程量十分巨大。针对目前泥石流防治工程流量计算中获取流域特征参数工作量大、低效等问题,本文在确定出研究区最佳分辨率为10m的DEM基础上,用MATLAB数学软件实现了目前较新的"三方向算法"洼地填充处理,消除了传统算法中河流"平行线"现象,较好保留原始地形信息,成功构建出水文地貌关系正确DEM(Hc-DEM)。提取出水网和相关流域等数据,经有机结合处理,并结合研究区泥石流特征,在苏保河泥石流沟上游设计一工程防治点,利用GIS技术成功实现了泥石流流域面积F、主沟长度L和主沟床平均纵比降J等参数的自动、快速、准确提取。在MATLAB平台下设计出暴雨洪峰流量和泥石流洪峰流量计算的自动算法,结合研究区实际情况,最终实现泥石流流量的计算。研究表明,在泥石流防治工程流量计算中,多功能软件及优化算法的集成,可以快速有效的实现泥石流相关参数的自动获取和流量的智能计算,满足了日益增加的泥石流防治需求。     

Comparative studies on fouling of homogeneous anion exchange membranes by different structured organics in electrodialysis

Five negatively charged organic compounds with different structures, sodium methane sulfonate (MS), sodium benzene sulfonate (BS), sodium 6-hydroxynaphthalene-2-sulfonate (NSS), sodium dodecyl sulfate (SDS), and sodium dodecyl benzene sulfonate (SDBS), were used to examine the fouling of an anion exchange membrane (AEM) in electrodialysis (ED), to explore the effect of molecular characteristics on the fouling behavior on the AEM and changes in the surface and electrochemical properties of the AEM. Results indicated that the fouling degree of the AEM by the different organics followed the order: SDBS?>?SDS?>?NSS?>?BS?>?MS. SDBS and SDS formed a dense fouling layer on the surface of the AEM, which was the main factor in the much more severe membrane fouling, and completely restricted the transmembrane ion migration. The other three organics caused fouling of the AEM by adsorption on the surface and /or accumulation in the interlayer of the AEM, and exhibited almost no influence on the transmembrane ion migration. It was also concluded that the organics with benzene rings caused more severe fouling of the AEM due to the stronger affinity interaction and steric effect between the organics and the AEM compared with organics with aliphatic chains.     

基于气溶胶光学特性的颗粒物来源分析

为初步探讨利用气溶胶光学指标判别污染物来源的适用性,选取天津市冬季一次重污染过程（2017年11月17—21日）,对气溶胶的七波段吸收系数、三波段散射系数及其化学组分进行在线观测及分析,研究气溶胶光学特性的变化,并结合化学组分定性分析污染过程不同阶段的污染来源.结果表明:SSA（单散射反照率）可以从散射性组分和吸光性组分对消光贡献的变化判断污染来源.污染积累期,颗粒物中散射性组分（SO₄2-、NO₃-、NH₄+）的增幅高于吸光性组分EC（元素碳）,导致污染积累期的SSA值高于污染前期和污染消散期,说明污染积累期存在较明显的二次转化过程.SAE（散射波长指数）可以从粒径角度推断污染来源.此次观测的污染积累期SAE值呈较明显的下降趋势,说明在细粒径段（2.5 μm以下）颗粒物粒径有增大的趋势,这主要与颗粒物中无机盐的吸湿增长及颗粒物之间的碰并有关.AAE（吸收波长指数）在一定程度上可以指示吸光颗粒物的类型.污染前期,BrC（棕色碳）在370、470 nm处对光吸收的贡献率分别为50.7%、33.8%;同期PM_2.5中ρ（Cl-）、ρ（K+）同步升高,卫星遥感显示,观测点周围有大量火点出现,推测主要受祭祖活动的影响.研究显示,气溶胶光学指标能够从散射性组分和吸光性组分对消光贡献变化、粒径变化、吸光颗粒物类型角度定性解析一部分污染来源,但其对于燃煤源和机动车等重要源类的指示作用还有待进一步研究.      

基于贝叶斯公式的地下水污染源及含水层参数同步反演

针对非均质地下含水层污染源识别及含水层参数反演过程中监测方案优化问题,提出一种基于贝叶斯公式及信息熵最小的累进加井的多井监测方案优化方法.首先,构建假想案例下的二维非均质各向同性潜水含水层水流及溶质运移模型,运用GMS软件进行数值模拟求解.采用最优拉丁超立方抽样方法和Kriging法建立数值模拟模型的替代模型.然后以参数后验分布的信息熵最小为目标函数,采用累进加井的方式进行多井监测方案优化设计.最后根据优化后的监测方案,采用差分进化自适应Metropolis算法进行污染源及含水层参数的同步反演.算例研究表明：在兼顾反演精度及监测成本,并保证每个参数分区内至少有1眼监测井的条件下,5眼井组合监测方案（6,5,1,2,8）为最优监测方案.与信息熵最小的10眼井组合监测方案（1,2,3,4,5,6,7,8,9,10）的参数反演结果相比,5眼井组合监测方案对11个参数α=（X_S,Y_S,T₁,T₂,Q_s,K₁,K₂,K₃,DL₁,DL₂,DL₃）的后验均值偏离率的平均值虽增大1.2%,但监测成本却是10眼井组合监测方案的50%.     

中国重化工业资源消耗的社会经济驱动力

基于投入产出模型和中国投入产出表,从需求端分析中国重化工业资源消耗的隐含流在不同行业和不同最终需求中的分配情况,以及五大社会经济驱动力对中国重化工业资源消耗增长的贡献度.结果表明,2012年中国重化工业生产过程所消耗的3种资源隐含在建筑业和其他制造业的最终产品中的比例均超过75%,隐含在形成资本最终产品中的比例均超过55%.2002~2012年期间,产业结构对中国重化工业化石能源和石灰石消耗量增加的贡献度分别为+39%和+237%;资源强度对中国重化工业化石能源和石灰石消耗量减少的贡献度分别为-108%和-265%,对中国重化工业铁矿石消耗量增加的贡献度为+152%;人均最终需求水平对中国重化工业化石能源、铁矿石和石灰石消耗量增加的贡献度分别为+247%,+460%和+291%.     

Cervical musculoskeletal disorders and their relationships with personal and work-related factors among electronic assembly workers

IntroductionElectronics assembly workers are reported to have a high prevalence of musculoskeletal disorders (MSDs). This study investigated the prevalence of cervical MSDs and the complex relationships between cervical MSDs and individual, physical, psychosocial factors among electronics assembly workers. Methods: In this cross-sectional survey, self-administered questionnaires from 700 workers in electronics manufacturing workshops were analysed. Information concerning musculoskeletal symptoms, personal and work-related factors was collected. Finally, the prevalence of cervical MSDs was computed for different subgroups, and the relationships with different factors were analyzed using logistic regression and structural equation modeling (SEM). Results: The total 12 month prevalence of cervical MSDs among the survey population was 29.4%. Variables of gender, job tenure, twisting head frequently, neck flexion/extension for long time and work required to be done quickly showed significant associations with MSDs in a multivariate logistic regression (P < 0.05). The SEM analysis showed moderate and significant correlations between postural load (γ = 0.279), gender (γ = 0.233) and cervical MSDs, while there were weak but significant correlations between vibration (γ = 0.024), work stress (γ = 0.126), job tenure (γ = 0.024) and cervical MSDs. Both work stress and vibration affected the MSDs indirectly through postural load. Conclusions: The logistic regression results support previous general epidemiological MSD studies, and indicates that individual, physical, and psychosocial factors are related to cervical MSDs. The SEM provides a better approximation of the complexity of the relationship between risk factors and cervical MSDs. Improving awkward postures may be effective ways to control the influence of occupational stressors or vibration on MSDs. Practical Applications: The study is to improve prevention of MSDs among electronics assembly workers and promote their occupational health.     

铝筒拉深模的参数化CAD

给出了开发铝筒拉深模参数化计算机辅助设计软件的思路。应用该软件 ,可以通过人机对话方式输入铝筒的相关参数 ,自动完成铝筒拉深模的理论计算和绘图。显著提高了设计质量和效率。     

ASM中水质特性参数测定方法的研究进展

近三十年来有关活性污泥生物学、反应动力学等基础理论方面的研究得到了迅速的发展。但用于模拟污水处理厂处理的模型的研究却发展相对较慢,本文综述了活性污泥数学模型的相应理论及发展历程。主要介绍了广泛应用的ASM模型,并详细介绍了模型中的水质特性参数(Ss、S1、Xs、x1)的各种测定方法。     

大别山东南麓韧性剪切构造带

广济县四望、松山咀和黄梅县大河、苦竹及宿松县界岭、二郎河一线存在一条规模较大的平移—推覆型韧性剪切带,其延60余公里,宽约5—15km。该带中糜棱岩岩石的斑晶及眼球体压力影不对称、重结晶石英斜列方式及微褶皱形态特征反映出以左旋剪切作用为主。有限应变沿x方向最大拉伸量为170％,沿z方向最大缩短量为57％。中心部位的糜棱岩明显经历了热加工—恢复作用阶段,是深层次韧性剪切的产物,古差异应力平均值为158.76MPa,应变速率为3.67×10~(-11)～6.17×10~(-12)sec~(-1)。晚期又遭受了脆性薄皮冲断作用。