基于Kriging模型的载人航天某装置结构优化设计研究

对于处在振动环境中的载人航天某装置复杂结构,设计过程中存在最小化质量、同时最大化一阶整体振动频率的多目标优化问题,可以利用多目标遗传算法(NSGA-II)求解得到Pareto最优解集,但利用NSGA-II进行求解计算量大,对于复杂结构更甚。为了节省计算时间,提出基于Kriging代理模型的复杂结构多目标优化设计方法,首先通过拉丁超立方采样获得样本点,然后通过样本点创建Kriging模型,最后利用多目标遗传算法求解代理模型得到Pareto最优解集,方便设计师从中选择最优解,优化结果表明本文所述方法合理有效。     

基于激光雷达分析一次重霾过程混合层高度

为深化对冬季重霾天气大气混合层高度的认识,利用Mie散射激光雷达观测了成都市2014年1月23日至2月4日一次典型重霾天气过程。基于Mie散射激光雷达探测获取的后向散射系数,使用SBH99算法计算了该过程的混合层高度,并系统分析其演变特征及其与气象因子的关系,研究结果表明:将激光雷达探测的混合层高度与探空曲线表征出的混合层高度进行对比分析,结果显示两者具有较好的一致性,相关系数为0.893 4;此次重霾过程中,混合层高度平均值较低,约378 m;霾天气发生后,混合层高度显著下降,并且混合层高度的最大值与最小值之间差距缩小,日变化波动不明显;混合层高度的发展与空气温度的变化趋势呈正相关关系,与相对湿度呈负相关关系。     

几种物质对萘乙二胺光度法测定苯胺的干扰

实验发现,亚硝酸盐、重氮化合物、2 萘胺 1 磺酸对苯胺有很强的干扰。亚硝酸盐的干扰可以通过加过量的氨基磺酸铵去除;蒸馏是去除重氮化合物、2 萘胺 1 磺酸干扰的有效方法。     

A spatial zero-inflated poisson regression model for oak regeneration

Ecological counts data are often characterized by an excess of zeros and spatial dependence. Excess zeros can occur in regions outside the range of the distribution of a given species. A zero-inflated Poisson regression model is developed, under which the species range is determined by a spatial probit model, including physical variables as covariates. Within that range, species counts are independently drawn from a Poisson distribution whose mean depends on biotic variables. Bayesian inference for this model is illustrated using data on oak seedling counts. Received: May 2004 / Revised: December 2004     

基于遗传算法的大庆市黎明河环境需水量优化配置

为克服水环境管理领域中多目标优化模型加权法求解时主观性强的缺点,将遗传算法与河流水质模拟模型相耦合用于大庆市黎明河生态环境水量优化配置的研究。该模型充分利用遗传算法的开放性和全局搜索的能力,从而得到了较满意的调水方案。对调水方案实施后的河流水质状况进行仿真的结果表明,水质有明显的改善,从而进一步证实了遗传算法应用于城市内河的生态环境水量优化配置的可行性和有效性。     

Design of a water quality monitoring network in a large river system using the genetic algorithm

Despite several decades of operations and the increasing importance of water quality monitoring networks, the authorities still rely on experiential insights and subjective judgments in siting water quality monitoring stations. This study proposes an integrated technique which uses a genetic algorithm (GA) and a geographic information system (GIS) for the design of an effective water quality monitoring network in a large river system. In order to develop a design scheme, planning objectives were identified for water quality monitoring networks and corresponding fitness functions were defined using linear combinations of five selection criteria that are critical for developing a monitoring system. The criteria include the representativeness of a river system, compliance with water quality standards, supervision of water use, surveillance of pollution sources and examination of water quality changes. The fitness levels were obtained through a series of calculations of the fitness functions using GIS data. A sensitivity analysis was performed for major parameters such as the numbers of generations, population sizes and probability of crossover and mutation, in order to determine a good fitness level and convergence for optimum solutions. The proposed methodology was applied to the design of water quality monitoring networks in the Nakdong River system, in Korea. The results showed that only 35 out of 110 stations currently in operation coincide with those in the new network design, therefore indicating that the effectiveness of the current monitoring network should be carefully re-examined. From this study, it was concluded that the proposed methodology could be a useful decision support tool for the optimized design of water quality monitoring networks.     

NiOγ／-Al2O3反应吸附苯并噻吩

以等体积浸渍法制备了负载型NiOγ／-Al2O3吸附剂,在固定床反应装置上对含苯并噻吩的模型化合物进行反应吸附脱硫实验,考察了NiO负载量、模型化合物硫含量及活性组分的形态对吸附剂脱硫性能的影响,并用XRD、SEM—EDS分析、XPS分析对载体和吸附剂进行了表征。实验结果表明：NiOγ／-Al2O3吸附剂具有较高的穿透硫容,能有效脱除模型化合物中的苯并噻吩;反应过程中生成了NiS;C的沉积以及Ni的硫化物的生成导致了吸附剂的失活。     

低动力复合净水系统净化生态农庄景观池水质

采用生物填料、阿科蔓生态基和生态浮盆等材料构建低动力复合净水系统(LCWPS)进行生态农庄人工景观池水质净化技术示范研究。系统稳定运行后的周年监测结果表明,整体系统使人工景观池的CODMn、TN、NH4+-N、TP和浊度分别下降61.1%～62.8%、36.0%～39.9%、14.3%～35.7%、66.7%～79.5%和76.8%～79.8%,水质溶解氧浓度(DO)上升72.7%～126.0%,景观池水质达到《地表水环境质量标准》(GB3838-2002)中景观水域需要的V类水质标准,并能长期保持稳定。从管理维护成本角度考虑,利用LCWPS净化生态农庄人工景观池水质能达到节能节水的目的。     

计算机辅助事故树分析研究

计算机辅助事故树分析中,求最小割集和绘制事故树是非常重要的。实用中,由于事故树往往规模庞大且最小割集的数目难以预知,这就使传统的用不能动态扩充的数组实现的计算机算法在应用时受到很大限制。本应用VC＋＋（MFC）中可动态扩充的数组类数据结构,实现求最小割集的Fussell算法,并提出和实现“堆砖法”计算机辅助事故树绘图。     

湖泊富营养化评价的S型曲线通用表示式

在适当设定富营养化指标的“本底”值情况下 ,当指标值用对应于“本底”值的相对值表示时 ,可采用 S型曲线描述湖泊富营养化发展程度 ,从而公式中的参数可视为与指标特性无关 ,采用遗传算法对公式中的参数优化 ,得到对多项指标通用的富营养化程度的指数计算公式 ,并用广义对比因子赋权新方法计算富营养化综合指数。该评价方法物理意义明确 ,计算简单 ,使用方便 ,具有可比性和通用性