小溶性顺酐共聚物与铬8离子配合物研究

本文通过引入第三单体合成了几种改性马来酸酐一苯乙烯水溶性共聚物，将其与铬离子络合制成高分子金属配合物，并对影响其配铬量的因素进行了研究。初步认为顺酐共聚物与铬离子配合物作为鞣剂使用的基本条件为pH=5-6、浓度为30％。     

壳低聚糖Cr(Ⅲ)离子配合物的制备及其结构表征

本试验用壳低聚糖与铬(Ⅲ)离子配合生成壳低聚糖铬(Ⅲ)离子配合物,研究pH值、温度、底物浓度、时间对结合率的影响.并对其结构进行了初步研究.红外、紫外-可见光谱分析结果表明壳低聚糖与铬(Ⅲ)能形成稳定的配合物,其配位的基团是-NH2基.铬离子的结合率高达25.04 %.     

壳低聚糖铬(Ⅲ)配合物制备工艺的研究

用壳低聚糖与铬(Ⅲ)离子配合生成壳低聚糖铬(Ⅲ)配合物,研究pH值、温度、底物浓度、时间对结合率的影响,并对其结构进行初步研究.分析结果表明,壳低聚糖与铬(Ⅲ)能形成稳定的配合物,经红外、紫外光谱分析其配位的基团是-NH2基,铬离子的结合率高达25.04%.     

回湿液中铬配合物的组成研究

为了解释回湿过程中,铬配合物从皮胶原中脱落的原因,以硫酸铬鞣制皮粉,鞣制皮粉干燥后,用0.2%甲酸和200%水回湿,得到回湿液。使用离子交换色谱对回湿液中的铬配合物进行分离;利用紫外-可见光谱和红外光谱对铬配合物进行分析。结果表明:湿液由+1、+2、+3、+4和+5价的铬配合物组成,其中高阳电性组分(+3、+4和+5价)含量为77.22%,是铬配合物的主要组分。回湿液中配体与中心离子之间形成桥键的数目较少,配合物体积较小。配体与中心离子之间主要以单点配位的方式相互结合,这种不稳定的配位方式,是造成铬配合物从皮胶原中脱落的主要原因。     

回湿液中铬配合物的组成研究北大核心

为了解释回湿过程中,铬配合物从皮胶原中脱落的原因,研究以硫酸铬鞣制皮粉,鞣制的皮粉干燥后,用0.2%甲酸和200%水回湿,得到回湿液。使用离子交换色谱对回湿液中的铬配合物进行分离;利用紫外-可见光谱和红外光谱对铬配合物进行分析。试验结果表明:回湿液由+1、+2、+3、+4和+5价的铬配合物组成,其中高阳电性组分(+3、+4和+5价)含量为77.22%,是铬配合物的主要组分。回湿液中配体与中心离子之间形成桥键的数目较少,配合物体积较小。配体与中心离子之间主要以单点配位的方式相互结合,这种不稳定的配位方式,是造成铬配合物从皮胶原中脱落的主要原因。     

回湿液中铬配合物的组成研究

为了解释回湿过程中,铬配合物从皮胶原中脱落的原因,研究以硫酸铬鞣制皮粉,鞣制的皮粉干燥后,用0.2%甲酸和200%水回湿,得到回湿液。使用离子交换色谱对回湿液中的铬配合物进行分离;利用紫外-可见光谱和红外光谱对铬配合物进行分析。试验结果表明:回湿液由+1、+2、+3、+4和+5价的铬配合物组成,其中高阳电性组分(+3、+4和+5价)含量为77.22%,是铬配合物的主要组分。回湿液中配体与中心离子之间形成桥键的数目较少,配合物体积较小。配体与中心离子之间主要以单点配位的方式相互结合,这种不稳定的配位方式,是造成铬配合物从皮胶原中脱落的主要原因。     

改性棉纤维铁配合物在废水净化中的应用

通过柠檬酸(CA)和乙二胺四乙酸(EDTA)的改性反应与Fe~(3+)离子配位反应制备了CA/EDTA改性棉纤维铁配合物(Fe-CA/EDTA-Cotton),并将其作为光催化剂应用于活性红195的氧化降解和Cr(Ⅵ)的还原反应中,重点考察了配合物的铁配合量、反应体系pH值和辐射光等对染料脱色率和Cr(Ⅵ)还原率的影响,研究了其对铬离子的去除性能。结果表明,Fe-CA/EDTA-Cotton对活性红195的氧化降解和Cr(Ⅵ)的还原显示出优良的光催化作用,增加铁配合量和辐射光强度能显著提高其光催化特性。酸性和中性能明显加强Fe-CA/EDTA-Cotton的光催化性能,碱性使之有所下降。此外,Fe-CA/EDTA-Cotton通过光催化还原反应和吸附效应对铬离子具有较好的去除性能,当反应体系中其添加量不断提高时,铬离子几乎被完全去除。     

鞣制时蒙囿铬液中铬配合物组成的变化和不同铬配合物与胶原的亲合力

蒙囿铬液中含有许多能与胶原选择性结合的各种配合物。本文用离子交换色谱法研究了这些溶液组成的变化。在高pH下,甲酸和乙酸的铬配合物中,带 2和 3电荷的配合物与胶原有较高的亲合力。与乙酸铬配合物相比,甲酸铬配合物的亲合力更大些。草酸铬配合物中的单草酸铬配合物与乙酸铬配合物的亲合力相近。阴离子乙酸铬和草酸铬的配合物亲合力非常小。     

聚丙烯酸-g-非离子性聚氨酯在铬鞣中的应用

以丙烯酸(AA)与可聚合非离子性聚氨酯表面活性剂(PUA)为原料,通过自由基共聚合成了一类高分子型的高吸收铬鞣助剂,采用FT-IR、1HNMR对其结构及形态进行了表征,并将其应用于铬鞣工序。研究结果表明:共聚物组成对该类接枝共聚物的实际应用效果影响明显,其中m(AA)∶m(PUA)为39∶1的共聚物Ⅰ具有更好的助铬吸收效果;而m(AA)∶m(PUA)为1∶19的共聚物Ⅱ则可使成革粒面更加细腻清晰,且对铬鞣革的热收缩温度影响较小。     

鞣制时蒙囿铬液中铬配合物组成的变化和不同铬配合物与胶原的亲合力

蒙囿铬液中含有许多能与胶原选择性结合的各种配合物。本文用离子交换色谱法研究了这些溶液组成的变化。在高ｐＨ下，甲酸和乙酸的铬配合物中，带＋２和＋３电荷的配合物与胶原有较高的亲合力。与乙酸铬配合物相比，甲酸铬配合物的亲合力更大些。草酸铬配合物中的单草酸铬配合物与乙酸铬配合物的亲合力相近。阴离子乙酸铬和草酸铬的配合物亲合力非常小。     

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