Optimum municipal wastewater treatment plant design with consideration of uncertainty

A newly developed model for the optimum municipal wastewater treatment plant (MWTP) design is presented. Through introducing the interval variables, the model attempts to consider the effects of uncertainties caused by the fluctuation of the wastewater quality and quantity during the design of MWTP. The model solution procedure is illustrated in detail, and a numerical example is given to verify the feasibility and advantage of the model. Furthermore, the possibility of the model application is briefly outlined.     

掺杂La3+纳米ZnO的制备及其光催化性能

采用共沉淀法制备了不同La3＋含量的La3＋-ZnO催化剂,采用x射线衍射仪、透射电子显微镜等对催化剂的结构、相组成、形貌和粒径进行了表征,比较了不同La3＋含量的La3＋-ZnO催化剂对罗丹明B降解率的影响。实验结果表明,掺杂La3＋导致ZnO粒径减小,比表面积增大,延长了光生电子-空穴对的寿命,提高了ZnO的光量子产率,La3＋-ZnO催化剂的光催化活性比ZnO显著增强。La3＋质量分数为0．8％时,罗丹明B降解率最高,为92．5％。经La3＋质量分数0．8％的La3＋-ZnO催化剂降解后罗丹明B已被完全降解为无机小分子。     

Selective removal of organochlorine pesticides (OCPs) from aqueous solution by triolein-embedded composite adsorbent

A novel composite adsorbent (CA-T) was used for the selective removal of organochlorine pesticides (OCPs) from aqueous solution. The adsorbent was composed of the supporting activated carbon and the surrounding triolein-embedded cellulose acetate membrane. Scanning electron microscopy (SEM), N2 adsorption isotherms and fluorescence methods were used to characterize the physicochemical properties of CA-T. Triolein was perfectly embedded in the cellulose acetate membrane and deposited on the surface of activated carbon. The adsorbent was stable in water and no triolein leakage was detected during the test periods. Some organochlorine pesticides (OCPs), such as dieldrin, endrin, aldrin, and heptachlor epoxide, were used as model contaminants and removed by CA-T in laboratory batch experiments. The adsorption isotherm followed the Freundlich equation and the kinetic data fitted well to the pseudo-second-order reaction model. Results also indicated that CA-T appeared to be a promising adsorbent with good selectivity and satisfactory removal rate for lipophilic OCPs from aqueous solutions when present in trace amounts. The adsorption rate and removal efficiency for lipophilic OCPs were positively related to their octanol-water partition coefficients (log K(ow)). Lower residual concentrations of OCPs were achieved when compared to granular activated carbon (GAC).     

免疫粒子群优化在波阻抗反演中的应用

针对标准粒子群优化(PSO)算法易出现早熟而陷入局部最优以及进化后期收敛速度慢等缺陷,引入免疫系统的免疫记忆和抗体浓度选择机制,构造了基于免疫机制的粒子群优化(IPSO)算法,并将其应用到波阻抗反演问题中。免疫记忆能够保留高适应度个体,抗体浓度选择机制进一步保证了粒子的多样性,从而能较好地避免早熟收敛,提高算法的全局搜索能力。对理论模型试算表明,IPSO算法在进行波阻抗反演时不仅收敛速度快,而且具有较高的精确度和抗噪性能。     

高层建筑火灾时走廊-前室缓冲区效果数值模拟研究

高层建筑火灾时,正压防烟带入的大量新鲜空气被送入着火层并稀释了烟气,降低了机械排烟效率.提出设置高层建筑条形走廊-前室缓冲区的设想,采用双方程κ-ε模型,对设置缓冲区后排烟效果的影响进行了模拟和分析.结果表明:建有前室缓冲区后,前室内烟气的平均质量分数远小于4.6％,前室在较长时间内处于安全状态.从走廊扩散至竖井的烟气分别经过走廊、前室两次降温,温度下降明显,在竖井中容易形成滞止状态,使其向上方其他楼层扩散的趋势降低,对整栋楼内人员疏散而言更为有利.     

分布式驱动电动汽车制动防抱死控制策略研究

针对分布式驱动电动汽车紧急制动工况下电机力矩与液压制动力矩的协调控制问题,提出一种制动防抱死双路控制策略。所提控制策略中,基于滑模变结构控制理论对液压制动系统进行制动防抱死控制,同时基于反模型控制理论对电机输出转矩进行调节。通过搭建包括双电机独立驱动系统的半实物仿真平台,进行了所提控制策略的仿真验证,证明所提控制策略能够使车轮滑移率更好跟随理想值,从而显著缩短紧急制动时的制动距离与制动时间。     

绿洲规模扩张的资源环境与生态阈限

本文系统分析了绿洲规模扩张的资源、环境与生态阈限。干旱区绿洲规模的扩张在总体上要受到资源、环境与生态阈限的制约。在绿洲经济发展过程中 ,无视这些阈限的制约 ,就会出现绿洲规模扩张的无度化 ,并产生一系列环境、生态问题 ,导致绿洲人地关系的极度失调。因此 ,要摒弃绿洲可无限扩张的认识。绿洲规模调控或绿洲适度规模的研究 ,应以这些阈限为理论基础 ,绿洲可持续发展在客观上也需要对这些阈限的深刻揭示。     

三峡库区的文物保护

三峡工程规模宏大，举世瞩目，具有防洪、发电、航运等综合效益，是开发治理长江的骨干工程，三峡库区位于长江上游河优的下段，受回水影响的水库淹没区和移民安置涉及的20个县市称库区，总面积约5．5万km^2，三峡库区已发现853处大型文物古迹，水库蓄水后大部分文物古迹将不受影响，但少部分将全部或部分受淹，中国政府一贯重视文物保护工作，三峡工程开工后，已拔出专门经费，组织人力物力，进一步加强文物古迹调查，考古勘探，加速古文化遗址的发掘抢救，切实保护三峡库区文物。     

毛纺废水中有机卤化物的产生,测定和处理

毛纺加工过程产生有机卤化物，以人类造成极大危害，近几年越来越受到重视，文章综述了有机卤化物的毛纺加工各工序中的产生，可吸附有机卤化物等的测定及其处理方法和相关立法状况。     

基于采煤塌陷成湖区分析沉积物中铁锰分布特征及随季节变化规律

为分析采煤塌陷成湖区的沉积物的铁锰含量和碱性磷酸酶活性随时间变化规律,对其环湖设20个采样点进行采样测量。结果表明,采煤塌陷成湖区的沉积物的Fe含量在0.061~1.731 mg/g范围内变化,夏季和秋季较高,冬季最低;采煤塌陷成湖区的沉积物的Mn含量在0.012~0.911 mg/g范围内变化,冬季含量最低,秋季含量最高;采煤塌陷成湖区的沉积物的碱性磷酸酶活性在53.15~560.03 mg/(kg·h)范围内变化,夏秋季较高,冬春季较低,在不同季节与Mn含量均存在正相关关系。第一层的铁锰含量以及碱性磷酸酶活性都较高,说明人类活动对采煤塌陷成湖区有较大的影响。