基于遗传算法和BP网络的造纸废水处理预测研究

在造纸废水处理过程建立出水COD预测模型中,针对BP算法易陷入局部极小、收敛速度慢等缺点,根据遗传算法(Genetic Algorithm-GA)具有全局寻优的特点,将两者结合起来形成一种训练神经网络的混合算法--GA-BP算法;仿真结果表明,预测模型具有较强的学习能力和泛化能力,同时,建立的GA-BP模型预测输出的平均误差仅为0.88%,说明此模型可以有效、可靠地预测造纸废水出水COD.     

BP神经网络预测废水处理过程的研究

通过在实验室条件下进行追纸废水处理试验取得的数据对BP神经网络进行训练，建立了造纸废水处理过程的网络模型。该网络模型仿真实际废水处理过程的结果表明，BP神经网络具有很强的学习能力。利用BP神经网络模型实现了对造纸废水处理过程的预测，平均相对误差为19％，表明网络泛化能力不是很好。经过动态训练的BP神经网络模型能够比较准确的预测造纸废水处理过程，平均相对误差为1．9％，大大优于未经动态训练的网络模型。     

相关向量机对废水处理系统出水水质的预测

准确预测出水水质对造纸废水处理过程具有重要意义,为此笔者提出一种基于相关向量机（RVM）的软测量模型。首先,利用偏最小二乘法（PLS）提取实际造纸废水处理过程数据的潜变量,解决过程变量的共线性和高维度问题,然后利用潜变量建立RVM预测模型。结果表明,与RVM模型相比,本文提出的PLS-RVM组合模型在对出水悬浮固形物（SS）的水质预测测试时,均方根误差降低了7.76%,决定系数提高了12.32%;但对出水化学需氧量（COD）的预测测试效果提升并不明显。此外,PLS-RVM模型的预测效果较PLS-LSSVM模型有显著提升：对出水SS的预测,均方根误差降低了9.16%,决定系数提高了15.29%;对出水COD的预测结果中,均方根误差降低了9.29%,决定系数提高了18.34%。     

基于ANN和LSSVR的造纸废水处理过程软测量建模

针对造纸废水处理系统的时变性、非线性和复杂性等特点,将人工神经网络(ANN)和最小二乘支持向量回归(LSSVR)分别用于造纸废水处理过程中的软测量建模,实现造纸废水处理过程中出水化学需氧量和出水悬浮固形物浓度的预测。ANN采用误差反向传播算法建模,LSSVR通过粒子群优化算法进行模型参数优化。结果表明,与ANN模型预测结果相比,LSSVR模型预测结果的均方根误差降低了50%以上,相关系数提高了近10%,表明LSSVR模型在造纸废水处理过程中的预测精度高于ANN模型。     

废水生物处理生化反应的建模和辨识

为废水处理过程建立一个准确的数学模型和对模型进行辨识的重要性是不言而喻的.本研究尝试用非线性最小二乘法对一种废水生物处理的数学模型进行辨识,从而为废水处理厂生产和控制的正常进行提供帮助.仿真结果表明,本研究采用的这种模型辨识效果良好.     

基于模糊神经网络的造纸废水处理预测研究

在造纸废水处理过程预测出水COD值中,建立一个五层模糊神经网络模型;运用样本数据训练模型与仿真,结果表明,预测模型具有较强的学习能力和泛化能力,同时建立的模糊神经模型预测输出的平均误差仅为2.55%,说明此模型可以有效、可靠地运用于造纸废水处理预测出水COD值中,并可方便地应用于其它工业废水处理过程中。     

组态软件及可编程控制器在造纸废水处理中的应用

针对一体化反应器处理造纸废水提出了运用自动化控制技术取代人工操作，在此基础上构建了造纸废水处理自动控制系统。该系统以工业控制机为上位机，PLC为下位机，辅以相应的监测仪器和采集模块，通过组态软件MCGS的管理和BP网络预测控制模型的挂接，完成实验室条件下造纸废水处理的自动控制，为进一步研究造纸废水处理自动控制提供可行途径。     

组态软件及可编程控制器在造纸废水处理中的应用

针对一体化反应器处理造纸废水提出了运用自动化控制技术取代人工操作,在此基础上搭建了造纸废水处理自动控制系统.该系统以工业控制机为上位机,PLC为下位机,辅以相应的监测仪器和采集模块,通过组态软件MCGS的管理和BP网络预测控制模型的挂接,完成实验室条件下造纸废水处理的自动控制,为进一步研究造纸废水处理自动控制提供可行途径.     

预测造纸废水出水指标的随机森林建模方法

出水化学需氧量(COD)与出水固形物含量(SS)是评价造纸废水处理工艺好坏的重要指标。为了更好地对其进行预测,提出了一种基于随机森林(RF)模型的方法,并以R语言为工具进行回归预测。对比偏最小二乘(PLS)模型、支持向量回归(SVR)模型、人工神经网络(ANN)模型等常规预测模型,发现RF模型具有预测精度高,结果误差小,泛化能力好,调整参数少等优点。在对出水COD进行预测时,RF模型的相关系数r为0.7954,相比于PLS、SVR、ANN分别提高了8.88%、10.73%、14.68%。在对出水SS进行预测时,RF模型的相关系数r为0.8551,相比于PLS、SVR、ANN分别提高了15.43%、24.25%、30.79%。     

铜川市卷烟需求集成预测

  目的   提高卷烟市场需求的预测准确率。  方法   通过建立ARIMA、VAR、SVR以及习惯性消费下卷烟需求模型,分别对铜川市卷烟需求量进行了建模预测,基于集成方法的思想,将上述四个模型的预测结果进行集成分析。  结果   集成预测模型对2017—2018年卷烟销量预测的相对误差绝对值控制在1%以内,平均相对误差绝对值控制在0.8%左右,预测结果显著优于单个模型,有效地提高了预测的精度。      

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.     

Analysis for organic residues from aids to polymerization used to make plastics intended for food contact

Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (¹     

Tests of potential functional barriers for laminated multilayer food packages. Part II: Medium molecular weight permeants

Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.     

The Ministry of Environmental Protection Issued "Feasible Technology Guidelines for Pollution Prevention and Control in Wood Pulping Process of the Paper Industry (Trial)" and Two Other Guiding Technical Documents

On December 27t＂, 2013, the Ministry of Environmenta Protection announced that, in order to implement ＂The Environmental Protection Law of the People＇ s Republic of China＂, improve the working system in environmenta protection technologies, and promote technologica advancement in pollution prevention, the Ministry of Environmental Protection sponsored the formulation of three guiding technical documents including ＂Feasible Technology Guidelines for Pollution Prevention and Contro n Wood Pulping Process of the Paper Industry （Trial）＂     

1~(st) Intelli-Tissue~ EcoEc Tissue Machine Supplied by PMP Group Successfully Put into Operation in China

正On April 29th,2014,Intelli-Tissue EcoEc tissue machine supplied by PMP Group successfully put into operation at Hebei Xuesong Paper Co.,Ltd.,this is the first such kind of paper machine of PMP Group in China.