优质金黄色工业金刚石的高温高压合成

在铁基触媒中引入添加剂,利用高温高压法,成功地合成了金黄色的工业金刚石。研究发现,随着添加剂含量的提高,合成金刚石的最低压力和某确定压力下的最低生长温度都呈增加趋势。另外,这种添加剂对金刚石的自发成核有一定的抑制作用,而且随其添加量的逐渐增加,这种抑制作用逐渐增强。在光学显微镜下进行观察,发现所合成的晶体呈完整的八面体形状,包裹体少,透明度高,优晶率达到80％以上。通过与无添加剂样品合成的金刚石进行对比,发现两种情况下所合成的晶体生长速度相近,晶体形貌相似,只是前者表面的凹坑呈三角形,而后者表面的凹坑呈圆形。     

立方氮化硼(cBN)特性综述

氮化硼是由氮原子和硼原子所构成的晶体,化学组成为43.6%的硼和56.4%的氮,具有四种不同的变体:六方氮化硼(hBN)、菱方氮化硼(rBN)、立方氮化硼(cBN)和纤锌型氮化硼(wBN)。文章对cBN的晶体结构、物理机械特性、光学性质、电学性质、热学性质、化学性质以及cBN晶体中杂质物相与hBN中B2O3含量的关系等做了简要的综述性描述,以便我们对cBN的基本特性有一个初步的了解。     

温度对PcBN切削刀具材料硬度的影响

PcBN切削刀具用于高速高温下加工铁基合金，为了准确地预测这种刀具材料的寿命，尤其了解在切削温度和切削压力下发生的变形和有关机理很有必要。本研究以维氏压痕作为一种手段来评估cBN含量、结合剂相cBN晶粒尺寸对几种PcBN材料机械性能的影响。研究表明，随着试验温度的升高，刀具材料的变形机理发生变化，经证实，压痕法有益于识别这种变化。     

影响cBN晶体生长及其特性的若干因素

影响cBN晶体生长及其特性的因素很多。文章就用M g3N2作触媒对cBN晶体得量和质量的影响、A lN添加物和不同气氛对cBN合成的影响、硼酐参与下cBN的形成、硅参与下cBN结晶过程等进行研究;对纤锌矿型氮化硼(wBN)参与下由hBN形成cBN的动力学以及VB族等价杂质元素对cBN单晶机械特性的影响等问题进行阐述。     

三水碳酸镁晶体形貌的调控研究

采用共沉淀法,用工业级卤水和纯碱制备棒状三水碳酸镁晶须。在一定反应时间和一定进料方式下探究晶体形貌的影响因素,得到最适宜条件为：反应温度35℃,卤水浓度1.5 mol/L,陈化时间60 min。在该条件下制备出的MgCO₃·3H₂O产品表面光滑,晶体发育完整,长度达到30μm。同时探究了40℃下小颗粒悬浮物和添加剂对MgCO₃·3H₂O产品形貌的影响,发现在40℃下小颗粒沉淀物对产品形貌有一定影响,但影响程度不大,而添加剂在40℃下则可以促进MgCO₃·3H₂O的晶体形成。     

国内外常用陶瓷cBN磨料的性能对比（上）

文章根据cBN磨料在陶瓷砂轮中的作用,凭借单颗粒抗压强度仪、扫描电镜、差热分析仪等先进精密仪器对国内外有代表性的8种磨料进行了常温性能、微观形貌、高温性能和耐腐蚀性能分析。实验表明,国产部分单晶cBN磨料的常温和高温性能已达到相当高的水平,甚至超过了国外产品的性能;同时,由于cBN磨料高温性能的提高,在陶瓷cBN砂轮制作过程中可以适当提高烧成温度以增加砂轮贴块的强度。     

国内外常用陶瓷砂轮的cBN磨料的性能对比（下）

文章根据cBN磨料在陶瓷砂轮中的作用,凭借单颗粒抗压强度仪、扫描电镜、差热分析仪等先进精密仪器对国内外有代表性的8种磨料进行了常温性能、微观形貌、高温性能和耐腐蚀性能分析。实验表明,国产部分单晶cBN磨料的常温和高温性能已达到相当高的水平,甚至超过了国外产品的性能;同时,由于cBN磨料高温性能的提高,在陶瓷cBN砂轮制作过程中可以适当提高烧成温度以增加砂轮贴块的强度。     

用双磁法测定小麦粉中的磁性金属物

随着制粉工业的发展，各种添加剂相继出现在小麦粉里。我们对市场上销售的多种面粉进行了抽样检测，发现它们均不同程度地加有添加剂。用GB5509—85中的磁性金属物测定器法测定小麦粉磁性金属物含量时，测定结果偏高，甚至使一些合格产品变成了不合格产品，而改用GB5509-85中的磁铁吸引法测定小麦磁性金属物含量时，虽受添加剂影响不大，但测定结果又偏低，反映不了小麦粉磁性金属物的真实含量。     

含铬革屑胶原水解物对石膏缓凝作用的研究

利用废弃含铬革屑在碱热条件下获得的胶原水解物对建筑石膏进行缓凝作用,实现废弃物资源化利用。研究了水解物对石膏的凝结时间、水化温度、绝干抗折强度及晶体形貌的影响。结果表明:随着水解物用量的增加,石膏的缓凝时间延长,而石膏的抗折强度逐渐降低,利用扫描电镜观察到石膏晶体的生长习性和形貌也发生了不同程度的改变,并从晶体变化的角度表达了水解物缓凝特征。     

PcBN复合片抗弯强度的分析

通过对不同温度下烧结PcBN复合片的cBN层抗弯强度(TRS)进行检测,发现在该实验条件下TRS值随着温度的升高而递增,穿晶断裂也随着温度的升高而增多,并且PcBN层边缘比中心的穿晶断裂数量多,粗粒度的以穿晶断裂为主。这说明温度对cBN颗粒间结合强度起主要作用。     

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.     

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