用海盐石膏制备水泥缓凝剂和增强剂的试验与研究

将海水制盐的副产品－海盐石膏，经适当处理后，能你替二水石膏，作为硅酸盐水泥的缓凝剂，同时能明显地提高水泥的早期强度，亦能增强水泥的后期强度，为海盐石膏的利用开辟了一条有效的途径。     

用海盐石膏制备水泥缓凝剂和增强剂的试验与研究

将海水制盐的副产品———海盐石膏，经适当处理后，能代替二水石膏，作为硅酸盐水泥的缓凝剂，同时能明显地提高水泥的早期强度，亦能增强水泥的后期强度，为海盐石膏的利用开辟了一条有效的途径。     

芒硝石膏综合利用的技术研究

通过用芒硝石膏替代天然石膏作为水泥缓凝剂的技术研究和试验,证明芒硝石膏可以替代天然石膏,同时可提高水泥早期强度;芒硝石膏的最佳掺量为5%-7%;芒硝石膏的CaSO4含量应保持相对稳定。     

水泥—消石灰—半水石膏固化粘土材料性能的试验研究

文章采用水泥单掺和与消石灰、半水石膏双掺试验的方法,对水泥、消石灰和半水石膏掺量与固化粘土样品的强度和耐水性能关系进行了详细的试验研究。研究发现:单掺水泥时存在一个最小水泥掺量13%和耐水性阀值17%,大于该掺量强度和耐水性都大幅度提高;水泥与消石灰双掺存在协同效应,大于单纯用水泥时的作用,双掺时消石灰最大掺量37.5%和最佳掺量12.5%,掺量超过最大阀值时,强度和耐水性会下降;水泥与半水石膏双掺时气养条件下存在协同效应,水养条件下不存在。     

利用磷石膏制硫酸联产水泥

针对目前我国磷肥工业固体废弃物———磷石膏垃圾的倾泄速度,及国家对磷石膏处理的要求,从磷石膏生产硫酸联产水泥的重要性、生产技术、工艺技术、创新特点几个方面阐述磷石膏制硫酸联产水泥的生产过程及磷石膏制硫酸联产水泥的经济效益和社会效益。     

水泥,石膏刨花板的生产

水泥、石膏刨花板的生产哈尔滨兴林公司邢航黑龙江省鸡西矿务局桦木林场范世杰东北林业大学姜晓冰内蒙古大兴安岭林业勘察设计院那林红１概述水泥、石膏刨花板是以水泥、建筑石膏（β型半水石膏）为胶结剂，木质、非木质刨花为增强材料，并加入适量的化学添加剂与水，用半...     

石膏微纤维用于纸张增强的初步研究

结合石膏微纤维的结构性能,对其在造纸中的应用进行了初步探讨,并得出了石膏微纤维应用于造纸时的最佳工艺条件.实验结果表明,在植物纤维中添加一定量的石膏微纤维,纸张的物理强度明显提高.     

石膏纤维对纸张增强作用的研究

研究了石膏纤维的加入对纸张强度性能的影响.研究结果表明:石膏纤维对纸张强度具有一定的改善作用,当石膏纤维加入量小于10%时,纸页各项强度均一定程度下降;加入量大于10%且逐渐增加时,纸页各项强度指标随石膏纤维加入量的增加而升高;石膏纤维加入量为35%叶,纸页各项强度达到最大值,继续加入石膏纤维则纸页强度逐渐下降;纸浆打浆度为55～60℃SR时,石膏纤维对纸张强度的改善作用最佳.     

江苏海盐区结晶单产低的原因与对策

对海盐生产结晶单产进行了研究,剖析结晶单产低的原因,并提出提高海盐结晶单产的办法.     

海盐与气象因子及地理分析

海盐是由海水蒸发结晶产的盐,海盐中含有钾、铁和铜等矿物质。依靠太阳的辐射热蒸发晒盐制得海盐,这是古老的制盐方法,也是目前仍沿用的普遍方法。本文对海盐与气象因子及地理的关系进行了分析。     

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.     

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.     

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.     

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.     

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.     

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.