不同水彩画纸绘画性能对比及影响因素分析

本研究对国内外常见6种水彩画纸的绘画性能进行了对比分析,进而研究了水彩画纸绘画性能的影响因素。结果表明,本研究建立的水彩画纸评价体系有效可行;不同水彩画纸的色差还原性、吸收性、耐擦性和耐久性存在较大差异;影响水彩画纸绘画性能的关键因素可能有纤维原料、填料、紧度、纸张的pH值。     

纸张吸收性检测方法的应用研究

研究烟用接装纸原纸、铝箔衬纸吸水性的检测方法,采用施胶度(液体渗透法)、施胶度(墨水划线法)、吸水性的测定(可勃法)、施胶度EST法和动态接触角法,分别对以上两个纸种具有代表性的试样进行检测和对比分析,最终确定每种纸最适用的检测方法。     

水彩画纸的特性及国内外发展现状

介绍了水彩画纸的分类和纸张特性,初步分析了水彩画纸特性的检测方法。阐述了国内外水彩画纸的市场现状、生产工艺及研究进展,提出了国内水彩画纸研究应解决的问题。     

卷烟接装胶的吸收性及对粘合性能的影响

本研究在对比分析接装胶性能基础上，通过动态接触角法、动态渗透法、斜面滚球法和90°剥离强度实验法等，对接装胶在接装纸表面的吸收性、渗透性、初粘性和粘合强度进行了研究。结果表明，接装胶在接装纸非印刷面的接触角随时间的变化及动态渗透情况与水不同，高黏度接装胶在多孔性接装纸非印刷面的吸收速率低，高固含量接装胶的动态渗透特征参数t_max和t₉₅小。上胶开放时间对接装胶的初粘性和最终粘合强度均有影响，随着上胶开放时间延长，因接装纸表面对接装胶的吸收，初粘性呈现先上升后下降的趋势，即存在一个最大初粘性的开放时间窗口，低于该时间点封合，不会影响粘合强度，但高于该时间点封合，可能会发生粘合不良问题。     

卷烟接装纸的液体动态渗透性能研究

在对比分析接装纸印刷面和非印刷面表面结构及性能的基础上,通过动态接触角法和动态渗透法,分析了接装纸印刷面和非印刷面的表面润湿和渗透性能,系统研究了液体在接装纸两面上的动态渗透过程。结果表明,接装纸的两面差异性导致了印刷面和非印刷面液体润湿和渗透的差异,动态渗透曲线的3个特征参数（t_max、t₉₅和A_b）可以表征不同来源接装纸的润湿和渗透性能。在0.5 s时,接装纸的非印刷面和印刷面接触角降低值的差值在8°以内,可以获得较好的上机适用性。     

烟用接装纸原纸施胶度检测方法的分析

目前我国用于检测烟用接装纸原纸施胶度的方法是采用GB/T 1540—2002纸和纸板吸水性的测定(可勃法),由于烟用接装纸原纸的特殊性,采用该方法检测其施胶度不能准确、真实地反映产品施胶度的要求。本实验对纸张施胶度的不同检测方法——可勃法、动态可勃法、可勃改进法(本方法)、EST法、动态接触角法等进行数据对比和分析讨论,找出采用可勃法检测烟用接装纸原纸施胶度不足的原因并加以改进。结果表明,采用可勃改进法(本方法)检测烟用接装纸原纸施胶度检测精度优于可勃法,其检测精度与EST法、动态接触角法比较接近,由于可勃改进法(本方法)对现有设备无改动、不增加成本,可以满足实际生产和研发的需要。     

EST12表面施胶度仪检测烟用接装纸原纸表面吸收性的研究

研究EST12表面施胶度仪检测烟用接装纸原纸表面吸收性与Cobb检测仪测量结果的相关性。结果表明,对于烟用接装纸原纸,EST12表面施胶度仪检测出的特性值(A10)与Cobb值具有强相关性,可替代Cobb检测仪对Cobb检测仪不能做出的表面性能进行评估。     

纸与纸板施胶度测试中的影响因素及问题

<正>施胶从广义上讲,是指对纸浆、纸张或纸板进行处理,使其获得抗拒流体渗透的性能。习惯上是指纸和纸板取得抗水性能的加工程序。为了取得不同的施胶效果,应用内部施胶和表面施胶两种方法。根据纸和纸板的质量要求,按施胶程度又可分为重施胶和轻施胶。经过施胶的纸和纸板,其抗水性能随施胶工艺、施胶量的不同有较大差异。为了对其抗水性能进行评价,造纸工作者研究出了许多方法,主要有墨水划线法、可勃吸水重量法、液体渗透法,人们习惯上称为施胶度试验法。这些方法因其试验原理不同,其适用性也不同。上述三种方法,已有国家标准。GB460-89 《纸和纸板施胶度的测定法     

用超滤和反渗透法浓缩牛奶与分离乳清的研究

<正> 本文对采用超滤法及反渗透法浓缩牛奶与分离乳清进行了研究。超滤实验测定了在一定条件下,使用不同材料和不同孔径的超滤膜时乳清的渗透速度,测定了压力、牛奶浓度和搅拌速率对渗透速度和截留率的影响。反渗透实验主要比较了几种膜的预压实方法;对在不同压力下,纯水透过速度和牛奶渗透液透过速度进行了对比;测定了不同压力对牛奶中非水成分截留率的影响。此外,初步比较了膜的清洗方法,对实验结果进行了简要的讨论。     

铜版纸印刷适性不同指标和印刷效果的相关性试验

本文通过统计分析测定的国内外铜版纸数据,找出纸面光泽度、别克平滑度、印刷表面粗糙度、K&N油墨吸收性、IGT印刷渗透性、二甲苯吸收性等印刷适性指标与印刷光泽度、印刷密度、印刷网点清晰性等印刷效果之间的关系;找出按不同方法测定的纸面平滑度值之间及不同方法测定的油墨吸收性值之间的关系;并采用二元回归的方法计算出铜版纸的印刷光泽度与别克平滑度和IGT印刷渗透性之间、印刷光泽度与印刷表面粗糙度和K&N油墨吸收性之间、印刷光泽度与印刷表面粗糙度和IGT印刷渗透性之间的全相关系数和关系式,进一步证明印刷光泽度主要取决于纸面微观平滑度和油墨吸收性的论断。印刷表面粗糙度和K&N油墨吸收性(或IGT印刷渗透性)能确切地表示这两项性能,应该用它们取代与印刷光泽度相关性甚差的别克平滑度和二甲苯吸收性。     

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.     

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.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.     

Analysis for organic residues from aids to polymerization used to make plastics intended for food contact

Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (¹     

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

Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.     

The Ministry of Environmental Protection Issued "Feasible Technology Guidelines for Pollution Prevention and Control in Wood Pulping Process of the Paper Industry (Trial)" and Two Other Guiding Technical Documents

On December 27t＂, 2013, the Ministry of Environmenta Protection announced that, in order to implement ＂The Environmental Protection Law of the People＇ s Republic of China＂, improve the working system in environmenta protection technologies, and promote technologica advancement in pollution prevention, the Ministry of Environmental Protection sponsored the formulation of three guiding technical documents including ＂Feasible Technology Guidelines for Pollution Prevention and Contro n Wood Pulping Process of the Paper Industry （Trial）＂     

1~(st) Intelli-Tissue~ EcoEc Tissue Machine Supplied by PMP Group Successfully Put into Operation in China

正On April 29th,2014,Intelli-Tissue EcoEc tissue machine supplied by PMP Group successfully put into operation at Hebei Xuesong Paper Co.,Ltd.,this is the first such kind of paper machine of PMP Group in China.