油脂稳定度测试方法比较

在传统的重量法,烘箱法,光照法,AOM法,CDM法等油脂稳定性测试的基础上,新近开发的光电子法,大幅度地节省了测试时间,为高稳定性油脂的测试提供了切实可行的新方式.     

轴类零件平面图的绘制方法与技巧

以一个轴为例,介绍轴类零件的几种画法与技巧。     

无水乙醇制备方法的研究进展

介绍了共沸精馏法、萃取精馏法、膜分离法和吸附法制备无水乙醇的方法及其研究进展,并评价了各种制备方法的优缺点,阐述了燃料酒精在国内外发展进程,分析了燃料酒精快速发展的原因,介绍了目前燃料酒精生产中需要解决的问题及对策。     

水中硝酸盐脱除技术研究进展

本文简述了硝酸盐的危害,介绍了物理化学法、生物法等硝酸盐脱除传统办法的技术现状及优缺点,讲述了光化学法脱氮技术的脱氮原理,为光化学法的研究方向提供参考。     

柞木制取化学浆

研究了柞木制取化学浆的适应性.结果表明,用KP、AS-AQ及NS-AQ法都可以制取得率较高、可漂性较好的化学浆,而且各项质量指标都可以达到或超过漂白亚硫酸盐法阔叶木浆的标准.     

一种用于测定纸浆中过渡金属含量的样品预处理方法

研究了一种用于测定纸浆中过渡金属含量的样品预处理方法(酸处理法).选择了最具代表性的铁为研究对象,通过对酸的种类和浓度、处理温度和时间等条件的选择及优化,得出最佳处理条件为:采用3 mol/L的硫酸溶液来分散纸浆(浆料浓度可视过渡金属离子含量的多少适当调整),然后将其装入密封的容器内在120℃下处理5h.通过与灰分法和消化法预处理后的测定结果比较可知,采用酸处理法对样品进行预处理,可使测定过渡金属离子含量的误差在7％以内,且克服了灰分法中硅化合物的干扰.     

频率测量方法概述

本文频率不仅是电测技术领域内一个最基本的参数,而且各种非电信号,如力学、声学等物理量都可以转换为电频率信号,并且频率信号的抗干扰性强、易于传输,测量精度高。对各种频率测量的方法和特点进行了介绍。     

阿魏酸糖酯合成的研究进展

阿魏酸糖酯类由于具有特殊的两亲结构以及在人体内起到的生理活性而广泛应用于医药、食品、化妆品等行业。综述了阿魏酸糖酯的化学和生物法合成,并比较了两者的优缺点,指出优化合成方法成为阿魏酸糖酯合成的研究热点。     

2-循环系数矩阵对称MSOR法收敛的充分必要条件

讨论了A为2-循环系数矩阵的线性方程组AX=b的对称MSOR迭代求解问题.在系数矩阵A为2-循环系数矩阵且相应的Jacobi迭代矩阵的特征值为实数或纯虚数时对称MSOR法收敛的充分必要条件,并举例说明所得结果的优点.     

非涂布纸印刷透印的检测分析方法研究

本文主要以双胶纸为例进行三因素五水平的印刷透印正交实验,探讨非涂布纸的印刷透印检测及分析方法。实验结果表明,印刷透印的四种表示方法"密度法、反射率法、色差法及SCAN-P 36:02和PAPTAC L.6U标准法"表征规律性及趋势相近;基于CIE94色差公式的通用方法表征的印刷透印ΔEpt94与上述4种表征方法的变化趋势一致,且其可以进一步区分纸张不透明度及油墨渗透性所引起的印刷透印现象。     

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.     

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     

INFOPRINT 2014 was Successfully Held in Dongguan

Sponsored by Printing and Printing Equipment Industries Association of China （PEIAC） and organized by Print China magazine, the Seventeenth Beijing International Printing Information Conference （INFOPRINT 2014） was successfully held on 11th Dec. 2014 at Dongguan Exhibition International Hotel.