YH—5A型电子清纱器电路的改进

文中介绍了ＹＨ－５Ａ型电子清纱器的改进电路，重点讨论了改进电路的检测部分和控制部分。     

YH—5A型电子清纱器电路改进

以YH－5A型电子清纱器为例,提供了一种提高其准确性的电路改进方案,即任何一种信号电压出现偏差,就立即切断主机电源,同时具有失电保护功能。     

接触线圈误接电压造成寄生电路分析

我公司一台75kW的电热管式干燥炉一段时间以来不能正常运行，经摄电工几次检修也不能正常运行，验收时，才发现它的真正原因是控制回路形成寄生电路。1工作情况该控制电路实际操作电源是C相，在开始测试工作情况时，按IQA，SJ不自锁，经修理后，瞬动接点能自锁，但不可靠，按ITA，IC即打开掉电，SJ不能返回仍保持吸会，3C也不能。在延时接点的带动下，延时断开。由以上现象推断以下几点故障：①和自锁接点不闭合②SJ延时接点不工作（由3C不返回现象推断）＠IC和ZC线圈的问题2查找故障及处理办法2．l更换SJ继电器（时间），因手头…     

蒸汽管路温度控制系统的电路设计

本文论述了纺织厂蒸汽管路单片机温度控制系统硬件电路的设计与实现方案，并对该系统的硬件电路的特点、系统的应用情况和系统的推广使用价值作了说明。     

润湿液自动控制装置

胶印是利用油和水相互排斥的原理进行的。胶印机的润湿装置向印版涂布润湿液，将印版非图文部分(空白部分)保护起来，使之不沾油墨。正确地控制向印版涂布的润湿液量，保持良好的水墨平衡是获得高质量印刷品的重要条件。给水量不足，会产生脏版现象；给水量过多，不     

单板剪切机时差自动控制电路

自动控制信号来自光探头。光探头安装在各出板输送带之间(见图1),根据需要可选用一组或几组(图示为三组)。剪切后单板经出板输送带输送通过光探头,在单板遮挡的瞬间,光探头向控制电路发出一个正脉冲信号。 设单板应剪切位置如图2所示。图中的“前沿”和“后沿”由人工点动按钮控制剪切,“等规格”由时差电路自动控制剪切。出板输送带带速v_2大于进板输送带带速v_1,利用这一速度之差来实现自动控制。因v_2>v_1,已剪单板的后沿经过距离L(整张     

分析供电末端电路功率因数的自动控制

随着社会的发展与进步,电力资源逐渐成为人们生活、工作中的重要组成部分,供电系统作为电力供应与输出的系统设施,必须保证其供电的可靠性、经济的适用性、操作系统的便利性以及发展的长远性,而供电末端的电路功率因数则是判断电力系统对能源利用能力的重要技术指标。从影响供电末端电路功率因数的因素出发,分析供电末端电路功率因数的自动控制,掌握供电末端电路功率因数的控制范围,从而有效提高供电末端电路功率因数,实现经济效益与社会效益的全面发展,满足人们生产与生活的需求。     

A456C型粗纱机控制电路改进

我公司对A456C型粗纱机进行变频器改造以后,为了进一步节能降耗,又对控制电路进行了改造.     

FA401型粗纱机下龙筋提前起降的预防措施

FA401型粗纱机三自动落纱程序是指满纱信号发出后,以下程序自动完成:(1)锥轮抬起,皮带复位;(2)下龙筋起降;(3)锥轮落底复位。三自动程序的正常工作能大大减轻挡车工的劳动强度,提高生产效率。但是,在日常使用中,由于挡车工操作不慎,经常碰触到皮带复位闭合行程开     

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.     

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.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press