一种自适应协调控制器

讨论了非线性系统的协调控制问题，提出了用传统ＰＩＤ控制器和神经控制器结合的方法实现未知非线性系统的自适应协调控制，还给出了神经控制器在线修正的再励学习算法．通过仿真实例，说明了多模式控制器协调模式的控制有效性及其在线控制优势．     

家用太阳热水系统产品质量国家监督抽查结果 2005年家用太阳热水系统产品质量抽查合格率90.2% 国家质检总局 产品质量监督司

家用太阳热水系统（太阳能热水器）是由太阳集热器．贮热水箱．管道及控制器等组成的节能产品产品类型主要分为真空管型，平板型和闷晒型。据统计．2004年全国已有家用太阳热水系统生产企业三干多家．总产量达到1350万平方米．     

链条锅炉自动化的尝试

我厂安装的SHL6．st／h刁．6MPa自动锅炉，配备了燃烧自动调节系统和给水自动调节系统。投运后，使蒸汽负荷变化很大的制浆车间取得了节约煤耗，提高热效率，提高蒸汽质量，减轻劳动强度和实现安全生产的目的。1锅炉燃烧自动化的方案简介在锅炉运行中，蒸汽压力和护胜负压是重要的工艺参数，而使燃料和空气维持适当的比例是燃烧过程的最佳操作条件。为此，锅炉燃烧自动化的任务是维持蒸汽压力恒定，保证合适的风煤比，使炉膛负压稳定。我们通过实现“热负荷”调节，“燃烧经济性”调节和“炉膛负压”调节，分别控制给煤量B、进风量F和引…     

煤粉锅炉出力不足及结焦问题的分析与处理

广西国发林业造纸有限责任公司动力车间煤粉锅炉为柳州锅炉厂生产的SHS25—2．45／400～AⅡ型锅炉，为前墙布置、固态排渣煤粉炉，采用直吹式制粉系统。由于给煤煤种经常发生变化，该锅炉在运行中经常发生结焦和熄火现象，不但无法满负荷运行(仅～65％的负荷)，而且锅炉结焦严重，特别是后墙十分严重，经常因结焦严重而被迫停炉打焦，严重威胁着锅炉的运行安全。为此，经过多方咨询和计算分析，决定通过改造解决该锅炉结焦和带负荷能力差的问题。     

浅析锅炉降压运行的危害及经济性

浅析锅炉降压运行的危害及经济性解放军９５１０工厂程洪波关键词：锅炉，压力，重油我厂使用的锅炉是武汉锅炉厂生产的ＷＧＺ一３５／３９—１１型锅炉，其设计参数：过热蒸汽压力为３．８２５ＭＰａ，温度为４５０℃。汽轮机为马一３５／５，设计参数进汽压力为３．４３...     

PA-30在锅炉DCS控制系统中的应用

随着计算机控制技术的日趋成熟，利用发展日益迅猛的计算机技术来对锅炉进行控制，近几年正为越来越多的用户所采用．计算机在锅炉的自动测试和控制方面的技术已成熟，它是计算机软件、硬件、自动控制、锅炉节能等几项技术紧密结合的产物，在锅炉计算机自动控制系统中采用DCS集散控制系统，系统     

锅炉过热器爆管原因分析

我厂有4台GB—65／3．82－M型锅炉，运行17年来，4台锅炉均多次发生过热器爆管事故，直接影响正常生产。为此，就锅炉过热器煤管的原因做了一些探讨，仅供参考。18留原因分析1．1化学监督不严，炉水含盐量大，锅炉运行水位偏高及汽水分离装置失效或部分失效，使饱和蒸汽带水，引起过热器管内结垢，传热系数大大降低，导致传热恶化，管壁超温爆管。1．2锅炉燃烧调整不当，燃料风量配比不合理，使火焰中心上移、偏高、偏斜或过长，水冷壁结焦，导致炉膛出口温度升官．体付执空管段貂想1．3当燃料中水分、灰分增加，炉膛负压大，炉膛过量空气…     

循环流化床锅炉在制糖生产上的应用

循环流化床燃烧技术是近十年来我国新发展起来的一种新型燃烧技术，是对传统链条炉与煤粉炉的一次革新。黑龙江友谊糖厂新上的两台35t／h循环流化床锅炉，经生产实践证明，运行稳定，状况良好，使全厂各项生产技术指标创近几年最好水平。循环流化床锅炉的优点是：①煤种的适应范围广，②燃烧效率高，③减少污染，④灰渣易于综合利用，⑤负荷调整范围大。制换工业要想改造现有的低效链条锅炉，并摆脱当今因煤种变化频繁影响锅炉出力，影响制塔生产的状况．循环流化床燃烧技术的发展已为我们选用锅炉提供了新的炉型。循环流化床锅炉在制糖生产…     

中低压链条锅炉增容节能技术改造

1引言我厂动力车间3台SHL20－25／400型链条锅炉，自1987年投入生产运行，锅炉出力仅为70％～80％，从未达到额定参数的20t／h，热效率低，能耗高，故障多，煤种适应性差。随着我厂生产规模的不断扩大，锅炉的产汽量，已不能满足生产的需要。为了彻底改变这种状况，经我厂有关技术人员多次考察论证，决定引进国内较先进的低携带率的循环流化床燃烧技术，对这3台链条锅炉进行增容节能技术改造。其技改的最终目的，一是提高锅炉的出力，二是降低锅炉燃料的消耗量。2循环流化床锅炉原理及技术特点2．1原理我厂锅炉技术改造，采用了典型的低携…     

蔗渣锅炉自动燃烧控制系统及其应用

锅炉是糖厂生产过程的心脏,为后工序提供血液,其均衡、稳定控制直接关系到产品质量和节能降耗水平。多年来,广西来宾永鑫小平阳糖业有限公司一直在努力探索通过采用自动控制系统提高锅炉燃烧效率,为均衡、稳定、安全生产提供条件。本文从糖厂蔗渣锅炉燃烧的现状、锅炉燃烧自动控制系统的原理等方面,论述永鑫小平阳公司锅炉燃烧自动控制系统的应用所取得的成果。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

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

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

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.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

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.