以DMTNF为电子传输材料的单层结构有机光导体的研究

本论文系统地研究了在由DMTNF（TNF的一种衍生物）为电子传输材料，DEH为空穴传输材料和Y－TiOPc或H2Pc为电荷产生材料构成的单层结构有机光导体的静电照相性能。研究结果表明光导体的量子收率和感光度与CGM浓度和充电极性有很大依赖关系。Y－TiOPc光导体的最高峰在800nm处，半衰曝光量为0.588μJ/cm^2（正充电），0.828μJ/cm^2（负充电）：H2Pc光导体正充电最高峰在780nm处，半衰曝光量为1．50μJ/cm^2（正充电），半衰曝光量为1．97μJ/cm^2（负充电）。     

Y-TiOPc的合成制备及应用

对Y－TiOPc的合成制备、晶型调节、晶型的稳定性、静电照相性能进行了全面研究，结果表明所采取的制备技术路线合理，晶型调节容易，所制备的Y－TiOPc粒径在0.1μm左右，在整个可见光和近红外光谱区域表现出良好的吸收和光敏特性。以这种Y－TiOPc为电荷产生材料制成的功能分离型和三组份单层结构有机光导体，在半导体激光的发光波长范围均表现出良好的感光度，最低成像曝光量在0．2μJ／cm2～0.5μJ／cm2。用Y－TiOPc制作的有机光导鼓经测试也具有良好的打印效果。     

一种新的空穴传输材料三苯胺双醛二苯腙的合成及其光导特性

本文合成了静电复印用电荷传输材料三苯胺双醛二苯腙，并用元素分析和氢谱对其进行了表征。用此化合物做空穴传输材料、Y－TiOPc做电荷产生材料制备了双层结构光导器件，其E1／2为0．81ux.s。     

互易律对有机光导体感光特性影响的研究

互易律对有机光导体的感光性能有何影响，通过对制备的以Y－TiOPc为电荷产生材料的有机光导体所作的测试实验，证明有机光导体并不遵守互易律，其感光度随光强的增加而降低，由于在光谱780－840nm波长范围内具有很高的感光度，故特别适合半导体激光扫描的要求。     

杯芳烃孔穴传输材料的合成及静电性能评价

设计并成功合成出一类新型的可用作有机光导体孔穴传输材料的以杯芳烃为母体的腙类衍生物，其分子含有4个电荷传输点，有利于进一步提高传输性能；制成有机光导体器件后测试其静电照相性能，可以满足有机光导体的使用要求。这将有助于促进电荷传输材料的制造开发。     

阻挡层对静电潜影稳定性的作用

本文介绍了静电照相的基本原理，考察了在光导体与基板之间和在光导体表面加入阻挡层，阻挡层材料及厚度对静电潜影的影响。     

碱水溶性成膜树脂的制备及性能考察

根据静电照相直接制版对光导材料的要求，以苯乙烯、丙烯酸、甲基丙烯酸为单体，按不同配比合成出成膜树脂Ｓｔ－ＡＡ和Ｓｔ－ＭＡＡ。通过分别测试它们的酸值、碱水溶解性和静电带电性，确定出当Ｓｔ与ＡＡ和Ｓｔ与ＭＡＡ配料的摩尔比在１．５∶１到１∶１之间时，成膜树脂的碱水溶解性较好，静电带电性能也较好。     

静电数字印刷机成像部件对印刷质量的影响

静电数字印刷机成像环节静电数字印刷工艺可分为6个步骤,依次为充电、曝光、显影、墨粉转移、熔化/定像、清理,其中经充电、曝光两步后,光导材料表面就可形成静电潜像,因此从此角度出发可将这两环节并称为静电数字印刷的成像环节。1.充电部件及原理充电目的在于使光导鼓或光导皮带表面产生均匀分布的电荷,为光源在光导体表面曝光做好准备。     

注射机塑化能力影响因素的探讨

塑化能力是指料筒与螺杆在单位时间内，所能提供熔融树脂的数量。螺杆要素如图1所示。螺杆塑化能力的计算。式中：Q──螺杆塑化能力（cm3／s）Ds──螺杆直径（cm）n──螺杆转速（r／min）h3──均化段螺槽深度（cm）一螺纹升角（°）μ1──螺槽中塑料有效粘度（MPa／s）μ2──间隙中塑料有效粘度（MPa／s）L3──均化段长度（cm）s一螺杆与料简之间间隙（cm）e一螺校法向宽度（cm）凸P一塑化时螺杆均化段处的压力差（MPa）通常在计算塑化能力时，将后两项略去当作一个常数项，用效率加以修正。即：式中：Q一塑化能力（g／S）p－一…     

无机碳源和有机碳源的相对含量和相互作用对螺旋藻混合营养生长的影响

在螺旋藻的混合营养生长中，若HCO3－浓度低（如0．05mol／L），螺旋藻优先同化葡萄糖时产生的一些有机副产物对其生长会产生抑制作用；而HCO3－浓度高时（如0．2mol／L），该抑制作用会减轻。自养生长条件下，在非开放的光生物反应器中，只要藻种未被污染，可采用0．05mol／LHCO3－培养螺旋藻而不会影响其生长。     

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.     

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.     

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.     

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.