熔盐水合物处理对生物质基多孔碳材料电化学性能的影响

本研究以速生杨木边材木片为原料进行自水解预处理,将无机熔盐水合物和自水解预处理后的杨木片（APW）加入盐酸溶液中浸渍,经冷冻干燥、碳化、酸洗、水洗及干燥后得到木质生物质基多孔碳材料。探究了APW的不同无机熔盐水合物活化处理对多孔碳材料物理结构性能的影响,测试了将其作为超级电容器电极材料的电化学性能。结果表明,在盐酸溶液中,无机熔盐水合物ZnCl₂和 ZnCO₃活化处理均有利于提高木质生物质基多孔碳材料的电化学性能,且前者比后者的作用效果更强,ZnCl₂活化处理制备的木质生物质基多孔碳材料无序结构更多;当用作超级电容器中的电极材料时,活化剂总质量一定,以ZnCl₂和ZnCO₃组合制备的多孔碳材料的电化学性能更具有优势,在0.2 A/g电流密度下,所制备的电极材料质量比容量可达到143.20 F/g;在2.0 A/g电流密度下,其循环5000次的电容保持率为99.90%;另外,在10 mV/s的扫描速率下,其循环伏安曲线保持了良好闭合的近似矩形形状。     

木质素基超级电容器碳电极研究进展

超级电容器是功率密度高、充放电速度快和安全可靠的绿色储能装置,其电极材料是超级电容器性能优劣的关键。可再生木质素具有含碳量高、来源广泛和成本低等优点,其通过活化、模板和纺丝等方法可制备出性能优异的木质素基超级电容器碳电极,具有较好的发展前景。本文主要介绍了木质素基超级电容器活性炭电极、模板炭电极和碳纤维电极,并对木质素基超级电容器碳电极的研究进行总结与展望,为新型高性能超级电容器电极材料的结构设计与制备提供参考。     

有机骨架衍生碳材料在超级电容器方面的应用

超级电容器相较于传统电容器具有更高的功率密度,更宽的工作窗口和更长的使用,近年来引起了广泛关注。许多有机骨架衍生的多孔聚合物材料,例如多孔有机骨架(POF),金属有机骨架(MOF),共轭有机骨架(COF)等衍生的电极材料在超级电容器中均表现出优异的性能。本文主要归纳总结了近些年来对有机骨架衍生碳材料在超级电容器方面的应用的一些研究。     

织物基柔性超级电容器电极材料的研究进展

探讨织物基柔性超级电容器的制备方式以及组成。介绍了柔性超级电容器的工作原理,阐述了近几年织物基柔性超级电容器的发展,涉及了电极材料、制备方法、电容结构和最终性能等。以碳纳米管、碳纳米纤维、石墨烯、活性炭等碳基材料为例,对比了几种超级电容器的电化学性能,并对此类柔性超级电容器电极材料的应用进行了总结与展望。认为:通过进一步的研究解决柔性超级电容器充放电循环数、电学性能和制备方式等问题,织物基柔性超级电容器将得到更大的发展。     

二氧化锰/碳复合电极研究进展

超级电容器是一种新型储能设备,具有功率密度高和使用寿命长等特点,从而受到人们的广泛关注。但超级电容器能量密度较低,限制其实际应用,通过将碳材料与二氧化锰复合成电极材料以提高超级电容器的能量密度。综述使用化学气相沉积法、水热法、电沉积法、静电纺丝法、模板法制备二氧化锰/碳复合电极材料在超级电容器中的相关研究,并且对其发展趋势进行展望。     

黄豆渣基多孔碳在超级电容器中的应用研究进展

我国是农业大国,黄豆产量高,对于黄豆制品的需求量也高,每年产生大量的黄豆渣废弃物,不仅浪费资源而且对环境也产生不良影响。现拟阐述黄豆渣多孔碳作为超级电容器电极材料的应用研究进展情况,为进一步的实际应用提供理论依据。将黄豆渣废弃物综合利用制备成具有高性能的电极材料,并应用于超级电容器中,真正实现生物质废弃物的绿色再利用,具有重大研究意义。     

革屑基复合炭材料的制备及在固态超级电容器中的应用

炭材料作为研究最早、使用最广泛的超级电容器电极材料,具有良好的热稳定性和化学稳定性,但传统炭材料的制备往往受成本、资源和环境等问题的限制,而生物质炭材料不仅具备孔隙率高、导电性能好等优异性能,且原料来源丰富、成本低廉。本实验采用废弃生物质——植鞣革屑为原材料制备多孔炭,相比于纯的胶原前驱体,植鞣剂单宁有助于碳元素含量提高。而后用化学氧化聚合法在多孔炭材料基底上原位生长聚吡咯进一步提高碳元素含量,再次炭化后制备得到高碳元素含量的革屑基复合炭材料。电化学测试表明,在三电极体系中,当电流密度为1 A/g时,电极比电容值可达330.5 F/g,并具有良好的倍率性能。由该材料组装而成的固态超级电容器,具有高的比电容值,在500 mV/s下进行5000次充放电循环后电容保持率接近100%。     

木质素基多孔纳米碳纤维在超级电容器电极材料中的应用

以乙酸木质素、聚氧化乙烯、乙酰丙酮铁和聚乙烯吡咯烷酮为原料,通过静电纺丝以及随后的碳化过程制备得到木质素基多孔纳米碳纤维,将其用作超级电容器电极材料。多孔碳电极在0.5A/g的电流密度下的比电容值为67.05F/g,比未添加开孔剂的木质素基碳纤维电极提高了88%。多孔碳电极还具有良好的循环性能,在0.5A/g的电流密度下循环1000次后的保留电容为初始的92%。此外,木质素基多孔纳米碳纤维由于开孔效果比表面积增加,微孔和介孔的增加促进了电解液离子的转移和吸附,增强了材料的电化学性能。制备的木质素基多孔纳米碳纤维表现出来的性能使它们具有作为能源存储的可能性。     

超级电容器中纳米纤维素基电极的研究进展

纳米纤维素机械强度高、密度低且表面含有可化学改性的羟基官能团,可作为组装高性能超级电容器电极的优选材料。本文综述了纳米纤维素与导电聚合物、过渡金属氧化物等活性材料制备超级电容器软材料和碳基复合电极的机理,对冷冻干燥、碳化、原位聚合、过滤、涂覆等组装方法进行了详细讨论,并对纳米纤维素基电极的机械性能和电化学性能进行了对比和分析。最后,对纳米纤维素基电极在超级电容器中的应用前景进行了展望。     

智能纺织用聚吡咯电极材料研究进展

聚吡咯材料因具有良好的导电性及柔韧性、价格低廉、易于合成而在柔性超级电容器中具有很大的应用潜力。文章首先介绍聚吡咯的制备方法,包括原位聚合和电化学聚合。然后阐述聚吡咯与碳基材料、金属氧化物、金属硫化物等复合电极材料的电化学性能及其在柔性超级电容器中应用的研究进展。介绍聚吡咯电极材料在智能纺织品中的应用。最后提出基于聚吡咯复合材料的柔性超级电容器电极材料存在的问题和未来发展方向。     

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