多种神经网络在华北西部区域城市空气质量预测中的应用

据华北西部区域4个主要城市2003—2012年API日报数据和相应时段的地面气象要素数据,利用4种(BP、Elman、T-S模糊、小波)神经网络构建预测模型并预测相应城市大气环境质量。研究结果显示,4种模型在可靠性、预测精度方面均可满足应用要求可用于实际预测;具有动态反馈能力的Elman神经网络的预测精度以及泛用性要优于具静态馈能力的其他3种网络模型,说明动态神经网络更适用于城市大气环境质量预测。4种神经网络的决策权重大小及其排序虽各不相同,但体现出相似规律性,日最低气温、日均气压、前日API对输出数据的影响较大,说明逆温现象引发的持续性、区域性污染是该地区主要环境问题。     

基于径向基函数网络的溢油预测模型

为了提高溢油预测的准确性,建立和优化溢油预测模型,提出了基于径向基函数网络模型的溢油预测方法,实现溢油预测功能。径向基函数网络模型解决了模拟预测过程中样本库巨大、函数模型收敛速度慢的问题。通过选择有效的输入参数和样本数据,建立局部逼近网络;通过径向基函数训练样本数据,利用输出值与实际值之间的误差作为约束条件调整权重因子、径向基中心和宽度,加快函数模型的收敛速度。该模型模拟了溢油的漂移、扩散过程,达到预测的目的。利用该模型,建立了溢油预测模块,并针对一次溢油事故进行预测模拟,验证了该模型的可行性,能够为应急决策提供一定的支持。     

徐州市道路交通噪声污染趋势预测与分析

根据道路交通现状与规划情况，通过分析，简化运用FHWA和灰色GM(1，1)模型，对徐州市2005年的道路交通噪声污染情况进行定量预测，并对两种模型的预测结果进行了分析和比较，为徐州市声环境质量保护目标的制定提供依据，也为其它城镇预测交通噪声提供方法和参考。     

基于X-12-ARIMA方法的武汉市空气污染指数波动分析

空气污染指数(API)用于表征区域空气污染程度和质量状况,其变动存在长期趋势、季节效应及随机扰动效应等特征。为探索API的波动规律,以武汉市2001—2012年API为例,进行X-12-ARIMA季节调整方法下的API演变趋势及内在规律探究。结果表明:在研究期内,武汉市API的变化受趋势成分的影响作用为85.2%;API月度及季节性变化显著;冬、春季节空气质量较差且变化不规则。最后,依据研究结果为武汉市空气环境质量的改善提出了建议。     

环境污染物排放的灰色线性幂函数预测法

基于ＧＭ（１，１）曲线，研究和提出了一种环境污染物排放的单变量灰色线性幂函数预测新模型（简称ＧＩＭ（１）），并建立了辨识模型参数的优化方法，研究结果表明，该模型较常用的ＧＭ（１，１）模型内涵丰富，外延清晰，表现出良好的逼近功能，为环境污染物排放预测，决策和控制提供了一种新方法。     

基于人工神经网络的居民生活垃圾可燃成分热值预测

研究采用BP、RBF和自适应神经模糊推理系统(ANFIS)对生活垃圾可燃成分的热值进行预测。结果表明,BP神经网络模型的预测准确率为93.36%,RBF模型为96.87%,ANFIS模型为91.06%,3种模型均可用于可燃成分热值预测,但RBF模型的预测准确率相对较高,更适用于可燃垃圾的热值预测。     

鸭河口水库水体总氮、总磷预测研究

根据鸭河口水库受纳点源及面源污染负荷情况，选择枯水期为预测时期，采用迪隆模型对鸭河口水库水体总氮、总磷进行预测研究，为鸭河口水库水质保持和富营养化防治提供基础数据。     

化学-生物絮凝工艺类神经网络模型比较研究

在化学-生物絮凝工艺中试研究的基础上，分别建立了基于BP类神经网络的多输入多输出（MIMO）模型与多输入单输出（MISO）模型。应用化学生物絮凝工艺中试6个不同工况的实测数据对2个模型进行训练，均表现出很好的收敛性。通过另外2个中试工况的实测数据对模型预测性能进行测试，MISO模型对化学-生物絮凝反应器出水的COD、TP和SS的预测相对误差均低于MIMO模型，其预测相对误差均在9%以下。研究表明，MISO模型是一个很易使用的建模工具，能很好地预测化学-生物絮凝工艺出水水质。     

空气自动站气路系统常见的故障及排除方法

以API空气自动监测站为例，介绍了该仪器在使用以及保养过程中，气路系统中常见的故障，分析了故障产生的原因，并提出排除的方法。     

基于人工神经网络的半连续式混合厌氧消化产气量预测

研究采用BP神经网络和模糊神经网络(FNN)模型对逐步提高有机负荷的半连续式餐厨垃圾和猪粪混合厌氧消化试验进行日产气量预测.结果表明,BP神经网络模型的预测准确率为77.63％,FNN模型为82.33％,2种模型均可用于产气预测,但FNN模型在传统神经网络模型基础上加入了模糊控制,可提高其准确率,更适用于混合厌氧消化产气量预测.     

Optimization of Height of Release of Air Pollutants

A number of key projects in the Environmental Protection Agency (EPA) particulate R&;D program having applicability to industry are presented. For electrostatic precipitators (ESP) there is presented the result of work on large diameter discharge electrodes which provide a decrease in penetration of up to a factor of 4 when compared to conventional small diameter electrodes. Also discussed is the multistage ESP which provides a collection efficiency that would require a collecting plate area 4 or 5 times larger with conventional ESP technology. The E-SOX technology makes use of the multistage concept to free up space in the ESP for SO₂ removals of up to 90%. Electrostatically augmented fabric filtration provides a reduction in pressure drop of about 5 0% as compared to conventional fabric filtration. Wind tunnel modeling of windbreaks for material storage piles indicates a potential for providing engineering design data that would allow significant emission reduction caused by wind erosion     

Investigation of the characteristics of the reflectivity of clouds

This paper investigates some of the reflectivity characteristics that clouds (when modelled as solid bodies) must exhibit to be compatible with observations that the reflecting surface of a cloud (i) appears almost equally bright across its face, (ii) is brightest when the cloud is opposite to the Sun but decreases in brightness as the cloud moves to other positions and (iii) increases in brightness with increasing optical thickness of the cloud in the observer's line of sight. These observations, respectively, are shown to imply that the peak value of the bidirectional total reflectivity from a cloud surface (i) increases in inverse proportion to the cosine of the angle between the Sun and the normal to the cloud surface, as the incident angle increases, (ii) appears to be directed back in the direction of the incident radiation, and (iii) increases as optical thickness of the cloud in the observer's line of sight increases. The results could have application in many fields (e.g. modelling diffuse radiance distributions for cloudy skies).     

Estimation of uncertainty of sampling for analysis of pesticide residues

Abstract

A computer model was used to take random samples from primary sample populations obtained from field trials to simulate the uncertainty of sampling for residue analysis of plant commodities and soil. The results indicate about 40%, 30% and 20% relative uncertainty when random samples of size 5, 10 and 25 are taken respectively, from a single lot. Therefore the sample size should be the same for establishing and enforcing legal limits.     

扬中生态环境建设的思考与实践

结合扬中生态环境的基本情况和存在的不足，进行了具体分析，对扬中未来生态建设的发展方向提出了建议及实施措施。     

实验室质量管理体系内部审核的实施

在实施ISO／IEC17025：1999标准《检测和校准实验室能力的通用要求》过程中，通过实验室质量管理体系内部审核的实践与系统分析，识别出内部审核实施阶段的关键环节，提出召开首次会议、收集审核证据、确定审核发现和召开末次会议的技术方法，对提高内部审核的质量和有效性、获得可靠的审核结论具有重要意义。     

次氯酸钠发生器的研制

介绍了电解法生产次氯酸钠的原理 ,并在原有生产工艺的基础上进行了重新设计和对设备的重新选择、改造 ,得出了各个工艺参数的最佳值 ,生产出高品质的次氯酸钠     

An application of the theory of kinematics of mixing to the study of tropospheric dispersion

The most common technique used for numerical simulations of tracer mixing is that of the numerical solution of the advection–diffusion equation with the unresolved fluxes parameterized using the similarity theory. Despite correct predictions of the overall directions of transport, models based on a numerical solution of the advection–diffusion equation lack sufficient accuracy to correctly reproduce the coupling of mixing with small scale processes which are sensitive to the microstructure of the tracer distribution. The objective of this paper is to revisit the basic formalism employed in numerical models used to investigate atmospheric tracers. The main mathematical method proposed here is the theory of kinematics of mixing which could be applied effectively for simulations of atmospheric transport processes. At the beginning of the paper, we introduce simple mathematical transformations in order to demonstrate how complex topological structures are created by mixing processes. These idealistic flow systems are essential to explain transport properties of much more complex three-dimensional geophysical flows. An example of the application of the kinematics of mixing to the analysis of tracer transport on a planetary scale is presented in the following sections. The complex filamentary structures simulated in the numerical experiment are evaluated using some commonly applied statistical measures in order to compare the results with the data published in the literature. The results of the experiment are also analysed with the help of simple conceptual models of fluid filaments. The microstructure of the tracer distribution introduced in the paper is essential to increase our understanding of atmospheric transport and to develop more realistic parameterizations of small-scale mixing. The presented results could also be used to improve calculations of the coupling between microphysical processes and tracer mixing.     

Spectrophotometric Determination of Atmospheric Acidity by means of the Displacement of the Equilibrium of Acid-Base Indicators

A method is described for determining acidity by means of the spectrophotometric determination of the displacement of the equilibrium of açid-base indicators. The method is simple, sensitive and free of known interferences. There is no dependence on costly or sophisticated equipment and the results obtained are reliable and reproducible.     

实验室质量管理体系内部审核的策划

在实施ISO／IEC 17025：1999标准《检测和校准实验室能力的通用要求》过程中，通过实验室质量管理体系内部审核的实践与系统分析，识别出内部审核策划阶段的关键环节，提出审核范围确定、审核计划和抽样方案制订的质量控制要求，为有序高效地实施内部审核提供了技术方法。