基于微观仿真的同站台换乘站客流疏散研究

旨在对同站台换乘站的客流行为和规律,以及对车站乘客疏散时的情况进行分析和研究。通过建立同站台换乘站的微观疏散仿真模型,利用微观仿真软件VISSIM对某即将建成使用的同站台换乘站的仿真模拟,直观地对客流的疏散过程和疏散人群分布状况进行动态观察,通过改变模型的参数设置,考察不同情况下换乘站的换乘效率,得出提高换乘效率的措施和建议,并最终为换乘站的设施设计和运营管理提供辅助设计与决策支持。     

三峡库区香溪河流域非点源营养盐输出变化的试验研究

综合三峡库区香溪河流域土地利用结构和水系特点，在三大支流出口处设置常规水质监测断面，于干流响滩处设置水文控制断面，通过断面水质水量监测，利用数字滤波法解析径流多源和污染多源，研究上游来流点源和非点源营养盐输出负荷变化。结果表明：受农业非点源污染影响，TN是高岚河（0788 mg/L）＞古夫河（0712 mg/L）＞南阳河（0567 mg/L）；南阳河受磷矿企业点源输入的影响，TP是南阳河（0323 mg/L）＞高岚河（0074 mg/L）＞古夫河（0053 mg/L）；断面流量与降雨量的相关系数〖WTBX〗R〖WTBZ〗2=0720 2；TN和TP非点源年负荷输出分别占总量的61%和40%的， 20100607次降雨径流监测分析发现此次降雨汇流期间营养盐TN和TP输出的非点源贡献率分别达752%和709%；营养盐负荷主要受径流量影响，TN和TP输出负荷与流量的相关系数分别是0963 6和0978 9     

基于F-AHP的产业转移后可持续发展评价模型构建与实证研究

本着系统思想， 运用F AHP法，依据现有相关数据和多位专家意见，从产业自身发展、产业与区域经济发展、产业与区域社会发展、产业与区域资源环境发展4个模块30个指标构建产业转移后可持续发展评价指标体系，建立包含指标间模糊关系矩阵和面向参评产业的模糊评价矩阵的评价模型。通过模型评价了2006～2009年江苏苏北各市转移产业的可持续发展水平和能力。模型结果表明：苏北五市近年来承接的产业已获得较好的生存能力和可持续发展能力，但从可持续发展度的分值来看，苏北各市转移产业的可持续发展水平还不高；相比于传统产业，各市目前转移产业的可持续发展水平普遍较高，但苏北五市承接的产业有较大的同构性。因此，苏北各市下一阶段应优先发展比较优势产业，错位承接转移产业并考虑其可持续发展能力的培育     

基于最优传递矩阵的层次分析法在桥梁震害评估中的应用

影响桥梁抗震性能的因素众多,鉴于传统的定量方法无法精确权衡各因素的影响程度,因此,考虑将不确定型层次分析法引入桥梁的震害评估中,对区间标度的合理选择作了简要讨论,运用1～9标度采集数据,兼顾10/10～18/2标度的精确性,对初始判断矩阵进行折算。利用最优传递矩阵的概念,对传统的AHP进行改进,直接求出各指标的权重值。并将此方法应用到实例当中,建立基于地震波、墩台基础、支座、结构因素、环境因素等多因素影响下的桥梁震害评估模型,得到桥梁最终的综合评估值。     

污泥转移SBR工艺处理低浓度生活污水

污泥转移SBR工艺是一种通过内部污泥回流实现污泥在不同SBR隔室间转移,从而增加污泥利用效率,提高系统除污效能的新工艺。以设计规模为240 m3/d、处理低浓度生活污水的工艺系统为对象,研究了新工艺在不同泥转移量(污泥回流比)下的除污性能,并与系统以传统SBR方式运行的情况进行了对比。结果表明,新工艺可以有效提高SBR反应器的容积利用率;采用30%的污泥回流比进行污泥转移,新工艺的处理能力比传统SBR工艺提高近1/2,除磷效率从46%提升至85%。出水各项水质指标均能达到国家排放标准的要求。     

南通地区冰后期泥沙沉积量和环境变化的初步研究

南通地区位于长江三角洲北翼，其冰后期的环境变化以最大海侵时期为界，之前为海侵期，表现为海水入侵，陆地面积减少。之后海面趋于稳定，长江泥沙在河口地区持续沉积的作用下，表现为南通地区的逐渐成陆过程。利用收集的84个分布于南通地区及附近的钻孔剖面资料，将其按不同厚度的沉积相进行整理，结合前人研究成果，根据不同的数据基础运用IDW（Inverse Distance Weighted）插值对南通地区冰后期沉积厚度分布和环境变化过程分别进行了初步研究。结果表明：南通地区古河谷区是冰后期主要的泥沙沉积区，沉积物厚度、体积和重量大于北翼地区，北翼前缘沉积要大于后缘。冰后期古河谷区沉积泥沙4 8922×108 t，北翼地区沉积泥沙1 0453×108 t，二者之比约为47〖DK〗∶10，泥沙沉积强度之比约2〖DK〗∶1。从冰后期海侵初期到最大海侵时期，再到南通成陆的晚期，南通地区水域面积比例先由622%上升到95%，再缩减到331%，陆地面积比例先由378%缩减到5%，而后又上升至669%。尽管钻孔资料可以为南通地区有历史记载之前的时期提供宏观的环境变化框架，但由于钻孔资料在测年数据及沉积相的划分方面分辨率较低，在表现南通地区历史时期的环境变化方面存在不足，需要结合考古、文物等历史资料和土壤分布等自然地理信息进行更为详细的研究     

Evaluation of food chain transfer of the antibiotic oxytetracycline and human risk assessment

There has been recent concern regarding the possibility of antibiotics entering the aquatic food chain and impacting human consumers. This work reports experimental results of the bioconcentration of the antibiotic oxytetracycline (OTC) by the Asian watermeal plant (Wolffia globosa Hartog & Plas) and bioaccumulation of OTC in watermeal and water by the seven-striped carp (Probarbus jullieni). They show, for the first time, the extent to which OTC is able to transfer from water to plant to fish and enter the food chain. The mean bioconcentration factor (dry weight basis) with watermeal was 1.28 × 10³ L kg⁻¹. Separate experiments were undertaken to characterize accumulation of OTC by carp from water and watermeal. These showed the latter pathway to be dominant under the conditions employed. The bioconcentration and biomagnification factors for these processes were 1.75 L kg⁻¹ and 2 × 10⁻⁴ kg g⁻¹ respectively. Using an aqueous concentration range of 0.34–3.0 μg L⁻¹, hazard quotients for human consumption of contaminated fish of 1.3 × 10⁻² to 1.15 × 10⁻¹ were derived.     

Electrochemical oxidation of herbicide bifenox acid in aqueous medium using diamond thin film electrode

The electrochemical oxidation of bifenox acid was studied at a boron-doped diamond thin film by cyclic voltammetry and galvanostatic electrolysis. The course of the electrolysis was monitored by measurement of chemical oxygen demand (COD) and by gas chromatography/mass spectrometry (GC / MS) analysis. It was found that exhaustive electrolysis leads to degradation and, ultimately, to mineralization of the starting herbicide. The degradation intermediates were identified showing that the oxidation process begins with the fragmentation of the molecule followed by reactions involving the hydroxyl radical, which is generated by the discharge of water. The study of the effect of current density and concentration showed that the degradation efficiency increases with decreasing current densities and increasing concentrations. The whole results were interpreted in a mechanistic scheme involving two oxidation pathways, the first is a direct oxidation at the electrode and the second uses hydroxyl radical as mediator of the oxidation. Finally, a kinetic study based on spectrophotometric measurements showed that the degradation process is pseudo first order.     

Strategies for improving the photocatalytic performance of metal-organic frameworks for CO2 reduction: A review

Photocatalytic CO₂ reduction is an appealing strategy for mitigating the environmental effects of greenhouse gases while simultaneously producing valuable carbon-neutral fuels. Numerous attempts have been made to produce effective and efficient photocatalysts for CO₂ reduction. In contrast, the selection of competitive catalysts continues to be a substantial hindrance and a considerable difficulty in the development of photocatalytic CO₂ reduction. It is vital to emphasize different techniques for building effective photocatalysts to improve CO₂ reduction performance in order to achieve a long-term sustainability. Metal-organic frameworks (MOFs) are recently emerging as a new type of photocatalysts for CO₂ reduction due to their excellent CO₂ adsorption capability and unique structural characteristics. This review examines the most recent breakthroughs in various techniques for modifying MOFs in order to improve their efficiency of photocatalytic CO₂ reduction. The advantages of MOFs using as photocatalysts are summarized, followed by different methods for enhancing their effectiveness for photocatalytic CO₂ reduction via partial ion exchange of metal clusters, design of bimetal clusters, the modification of organic linkers, and the embedding of metal complexes. For integrating MOFs with semiconductors, metallic nanoparticles (NPs), and other materials, a number of different approaches have been also reviewed. The final section of this review discusses the existing challenges and future prospects of MOFs as photocatalysts for CO₂ reduction. Hopefully, this review can stimulate intensive research on the rational design and development of more effective MOF-based photocatalysts for visible-light driven CO₂ conversion.     

溶解氧对好氧颗粒污泥影响的研究进展

好氧颗粒污泥技术是一种新颖废水处理技术。溶解氧(DO)是好氧颗粒污泥形成和稳定运行的一个重要参数。好氧颗粒污泥需要的曝气量大,能耗高。高曝气量带来的高DO浓度不利于氨氮通过SND去除。当DO扩散在颗粒内部受到限制时,颗粒中心形成的厌氧层不利于颗粒污泥的长期稳定运行。本文系统分析了DO浓度对好氧颗粒污泥影响的国内外研究现状,对好氧颗粒污泥中DO浓度这一重要参数的研究进行了总结。研究在低DO浓度下保持好氧颗粒污泥的稳定性有利于降低运行成本,采取合适的方法降低颗粒内部的扩散限制有利于增强颗粒的稳定性能。