一种弧形竹材的展平技术

竹展平是竹材高效利用的方式之一。现有的竹展平技术存在工序复杂、出材率低、表面质量差等问题,提出一种针对弧形竹材的新型展平技术,该技术包括材料预处理、展平和后期处理三个阶段,其中预处理阶段的分级,保障竹材精准加工,使壁厚保留率达56.82%,出材率达65.2%,分别比传统技术竹展平板提高了9.09%和21.71%;剖分的弧形竹片软化时间缩短了20～30s;展平阶段的展平设备由压刨机构、展开机构和反向压平机构组成,可一次完成去青、去黄、展平等工序;合理的后处理阶段干燥工艺使板材性能与刻痕竹展平板相比,密度和抗弯强度、顺纹剪切强度分别提高了8.2%、32.67%和30.12%,抗弯弹性模量增加了近一倍。该弧形竹材的展平技术有效提高了生产效率和自动化水平,对实现竹板材大规模生产具有重要意义。     

竹集成材家具绿色制造研究

家具的绿色制造是实现资源优化利用、环境保护以及家具制造业可持续发展的有效手段,而竹集成材作为一种环保型家具基材正在为人们所知,实现竹集成材家具的绿色制造也是顺应我国的可持续发展战略。本文在介绍家具绿色制造技术体系和竹集成材的基本概念的基础上,从家具绿色制造评价体系框架着手介绍家具绿色制造的整个生命周期中应注意的问题和遵循的原则,讨论如何从家具绿色制造体系的材料选择、绿色设计、绿色工艺、绿色包装到绿色回收处理五个方面实现竹集成材家具的绿色制造。     

竹集成材家具的设计要素探究

竹集成材是一种基于可再生资源的生态工程材料。其外观、物理力学、加工性能决定了它适合于家具设计与制造。竹集成材家具产品的设计可体现造型形态夸张、构件纤细优美、材料本色利用与混搭、标准化等特征。竹集成材家具有望成为一种主要的生态环保型家具。     

压缩竹投梭棒的研制

投梭棒为有梭织机的主要器材之一。五十年代我国开始生产竹投梭棒。竹投梭棒的原料为大围径毛竹,逐年采伐资源缺乏。且因织机高速,要求提高投梭棒性能。本文论述了压缩竹投梭棒的原理、工艺、性能和使用情况。压缩竹投梭棒在1515——280型、1515——250型和1515——75″织机上分别试用,完全符合实用要求。使用寿命最低限度可相当于普通竹投梭棒的2.5倍。与原工艺相比,可节约原材料60％。且缩短织机停台时间。节电,节约皮结。压缩竹材的生产工艺还可推广到综框木、吊综板、控制木和走梭板等的生产上去。     

重组竹Ⅰ型层间断裂韧性研究

重组竹已成为我国竹质工程材料的主流产品,确定层间断裂韧性的测试方法,对重组竹的制造工艺优化、设计使用分析等方面都具有重要意义。利用断裂力学的理论和方法研究其断裂破坏行为,选取紧凑拉伸试件测试法对重组竹TL、RL方向的Ⅰ型断裂韧性进行了研究分析。结果表明:TL试样断裂韧性均值为27.81MPa·mm0.5,RL试样断裂韧性均值为21.07MPa·mm0.5;试件厚度对TL试样断裂韧性无显著影响,对RL试件断裂韧性有显著影响且随厚度的增大而增大;建议重组竹紧凑拉伸断裂韧性测试试样的厚度设置为25mm。     

HYLLY家具———钢竹先锋

在第18届深圳国际家具展览会上,由深圳研发院生态产品研发部推出的竹集成材家具受到了市委市政府领导的高度重视,引发了家具行业内强烈的反响。该系列家具的推出对家具产业的发展具有重要的意义。该产品以我国特有的丰富竹生态资源为开发主体,其中,新产品HYLLY系列当中,—个主要的系列“钢竹先锋”就是将竹集成材和钢材两种材料有机的结合, 开发出来的适合现代青年人使用的家具。竹材与钢材结合开发出的竹钢家具,以设计风格简约为主,材料和工艺取自于可循环利用的钢材和竹材。竹家具泛指以竹子、竹集成材、竹人造板     

典型注塑模具型腔的机械加工工艺分析

当今在工业生产制造中广泛使用模具生产制造产品,如机械制造、造纸装备、汽车、电器、仪器仪表等行业中大部分产品是使用模具进行生产制造.模具制造的产品的优劣与模具零件的制造精度密切相关,模具的型芯模、型腔模等零件的制造精度往往决定产品的质量,因此研究如何提高模具零件的制造精度十分重要.基于此,文章从产品要求、零件图、机械加工设备、模具零件材料、加工刀具、切削参数和工艺安排等方面,分析了微型对讲机外壳的机械加工工艺.     

一种可重复使用的复合材料用芯模

新型航天器用复合材料部件的性能与纤维缠绕工艺有着非常重要的关系.目前在纤维缠绕工艺中主要使用组合式或水溶性芯模(陶瓷或盐制成)进行零部件生产.这些芯模的生产是劳动密集型的,浪费资源而且对环境不利.一种使用VeriflexTM--一种高科技形状记忆聚合物(SMP)制造的新型芯模生产系统已研制成功,此芯模具有可拆装与可重复使用的特性,因此大大地减少了劳动力的使用与资源浪费,并且将大幅度降低生产复合材料零部件的成本与时间.本文介绍了SMP材料在复杂弯曲部件纤维缠绕法生产工艺中的应用.     

云香竹、刺竹与杂竹硫酸盐法混煮制浆生产实践

对杂竹、云香竹与刺竹的化学成分、纤维形态、蒸煮实验和成浆物理性能评价的研究表明,杂竹、云香竹与刺竹无论是理论上还是实际生产,按照1：1：1的混合比例,可生产出满足新闻纸等文化用纸抄造工艺要求的化学浆。     

云香竹、刺竹与杂竹硫酸盐法混煮制浆

对杂竹、云香竹与刺竹的化学成分分析、纤维形态、蒸煮实验和成浆物理性能评价的研究表明,杂竹、云香竹与刺竹无论是理论上还是实际生产,按照1∶1∶1的混合比例,可生产出满足新闻纸等文化用纸抄造工艺要求的化学浆.     

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