刺辊齿条的齿形与梳理效果

直齿形和弧背齿形的AT5 6 10× 0 5 111齿条是梳理机刺辊专用齿条 ,通过工艺试验比较 ,说明弧背形齿条比直齿形齿条的梳理效果更好 ,纤维损伤更小。     

高产梳棉机高效高耐磨针布齿条的设计构思

从现代高产梳棉机对与之配套的锡林、道夫针布齿条提出的要求入手 ,分析了锡林道夫针布应具有的性能 ,介绍了AC2 0 35× 0 15 45 (S)、AD4 5 45× 0 2 0 90 (B)新型高效耐磨锡林、道夫针布齿条的特点。     

梳棉机刺辊齿条对纺纱质量的影响

通过对传统刺辊齿条与新型刺辊齿条的对比试验,初步分析了刺辊齿条对纺纱质量的影响和其在针布配套中的作用,得出刺辊齿条对梳棉机后部除杂、纤维损伤和成纱常发性纱疵影响显著的结论,并认为在普通梳棉机上使用AT5610×05611刺辊齿条较为适宜     

开发20系列锡林齿条的实践

通过对清梳联用 2 0系列锡林针布齿条 (SAC2 0 30× 0 15 5 0 )的研制 ,并与国外同类产品对比 ,说明该产品基本上达到了配套要求 ,可以替代进口     

对MFQZ-500×2000型嵌齿机的改进

我厂于 1998年引进江苏产 MFQZ-5 0 0×2 0 0 0型嵌齿机一台 ,通过使用发现有以下不足 :1.原导引齿条的导槽固定位置较高。齿条在穿过导槽到齿辊时 ,由于导槽至齿辊两点距离过长 ,齿条在穿引中左右摆动 ,容易产生倒齿现象。2 .齿条导引槽间隙过大 ( 2 .4mm)。齿条从导槽中穿过时 ,达不到将齿条顺直的目的。3.嵌齿机齿辊轴承座是死位置 ,配装其它型号齿辊有局限性。4.嵌齿机压轮与齿辊的距离不好掌握 ,顶得过紧容易倒齿 ,顶得过松齿条嵌不到底。根据以上分析 ,我厂对以下部位进行了改进 :1.将齿条导槽位置下移 40 mm,缩短导槽与齿辊间的距…     

蓝莓渗透脱水的研究

在不同的渗透温度 ( 4 5～ 65℃ )条件下 ,高果糖浆和蔗糖的有效水分扩散率 (Dm)分别为( 4 90 60～ 5 2 3 66)× 1 0 - 10 m2 /s和 ( 3 5 5 1 8～ 4 0 1 0 9)× 1 0 - 10 m2 /s,有效固形扩散率 (Ds)分别为( 2 7740～ 3 691 5 )× 1 0 - 10 m2 /s和 ( 1 3 1 63～ 2 691 5 )× 1 0 - 10 m2 /s的规律。在渗透脱水处理过程中Dm 和Ds 随处理温度升高而增加。经高果糖浆 ( 70°Brix)渗透脱水的蓝莓的平均体积比随温度升高而稍微下降。其相对密度随温度的升高也略有增加     

怎样焊接自锁齿条

我公司有两台600×3000型皮棉清理机,四台齿辊长度不一的清绒机,三台320×1200型清弹机,皮棉清理机使用的是自锁齿条,清绒机和清弹机使用的是镶齿式齿条。在没有缠齿机的情况下,我公司根据多年的工作经验和机械设计专业知识,设计制造了一台多功能缠齿机。经过对以上两种类型的齿条缠齿实践,效果很好。不论齿辊的长短都可缠齿而且缠齿时齿辊不必拆下,但在缠自锁齿条时有一个重点也是难点就是自锁齿条的焊接。因为600×3000型皮清机的自锁齿条总重是105公斤,而市场上销售的自锁齿条没有该规格的,必须用两卷规格为54公斤的自锁齿条缠成一个600…     

高锰酸钾-乙二醛-多羟基酚化学发光体系的研究

酸性高锰酸钾可以氧化乙二醛产生强的化学发光,而在一定范围内,多羟基酚邻苯三酚的存在能阻抑这种发光.采用流动注射技术,建立了高锰酸钾-乙二醛-多羟基酚体系测定邻苯三酚的化学发光分析法.方法的检出限为1.4×1-0 7m o l.L-1,相对标准偏差为1.27%(1×1-0 5m o l.-L 1邻苯三酚,n=11),线性范围为1.0×1-0 6~2.0×1-0 4m o l.-L 1.     

流动注射-化学发光法测定双氧水的分解率

在铁氰化钾-亚铁氰化钾存在的氢氧化钠碱性介质中,双氧水可氧化鲁米诺产生化学发光,结合流动注射技术,建立了一种测定双氧水漂白过程中双氧水分解率的新方法.该方法测定双氧水的检出限为1.75×10~(-5)mol/L,线性范围为2.1×10~(-5)～1.7×10~(-2)mol/L.相对标准偏差为2.9％(5.8×10~(-3)mol/L,n=11).     

10t×35m门式起重机改造方案

我公司水运原木码头有一台 1 0ｔ× 35ｍ门式起重机 ,多年来闲置不用 ,而新投产的技改项目之一的木材处理场需要一台 1 5ｔ×2 8ｍ门式起重机。为了节约资金 ,提高设备利用率 ,将其改造成 1 5ｔ× 2 8ｍ起重机 (图1 )。图 11　原 1 0ｔ× 35ｍ门式起重机主要性能起重量　　　　　 1 0ｔ起升高度　　　　 1 2ｍ跨度　　　　　　 35ｍ小车行走速度　　 49 4ｍ/ｍｉｎ大车行走速度　　 40 35ｍ/ｍｉｎ要改成 1 5ｔ× 2 8ｍ起重机 ,如图 1所示 ,先从中线中截去 7ｍ阴影部分 ,使其跨度变成 2 8ｍ。2　 1 5ｔ吊车主梁强度校核2 1　主梁受力情况…     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

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