大分子光引发剂的研究进展

综述了大分子光引发剂的研究现状和进展。简要叙述了大分子光引发剂的制备方法、引发机理。对小分子光引发剂和大分子光引发剂进行了对比,着重讨论了分子结构因素对引发性能的影响。     

光聚合引发剂研究进展

对最近几年光敏聚合引发体系的研究进展进行了评述，并就一些新型光敏引发体系及引发机理进行了介绍。     

铈盐－过硫酸盐复合引发体系的研究

铈盐－过硫酸盐复合引发体系的研究李朝阳，丘坤元（北京大学化学系，北京，１００８７１）关键词复合引发体系，铈盐，过硫酸盐，氧化还原引发本文研究了一种新的复合引发体系，即在传统的单独钟盐引发体系中引人过硫酸盐这一本身具有强氧化性的新组分，提高原体系的引发...     

新型水溶性硫杂蒽酮类光引发剂的光引发性能研究

利用红外光谱技术对六种新型水溶性硫杂蒽酮类光引发剂在紫外光聚合反应中的引发性能进行了测试,用相对峰面积法计算了聚合反应的转化率,并据此对引发剂结构与光化学性能之间的关系做了一定的探讨。结果表明该类光引发剂具有很高的光化学活性,而引发剂的结构直接影响引发性能。研究发现硫杂蒽酮母体上甲基的引入使引发剂的引发效率增大,而引发剂侧链上羟基的引入,则由于降低了质量转移的有效性并有可能使引发剂分子缔合,致命引     

环氧树脂的紫外光引发阳离子／自由基固化

研究了两类阳离子引发剂复合苯基硫钅翁盐和芳茂铁盐的紫外光引发活性以及它们分别与自由基引发剂的复合体系的增强光引发活性，并讨论了强氧化剂异丙苯过氧化氢对于芳茂铁盐引发效率的促进作用以及适量多元醇对于提高阳离子固化体系交联度所起的作用     

无机纳米材料表面引发自由基可控聚合反应

无机纳米-高分子杂化材料具有优异的性能及广阔的应用前景,引起人们的广泛关注.本文综述了无机纳米材料表面引发自由基可控聚合反应在合成无机-高分子纳米杂化材料方面的广泛应用,包括表面引发原子转移自由基聚合(ATRP)、表面引发可逆加成-断裂链转移自由基聚合(RAFT)、表面引发稳定氮氧自由基聚合(NMP). 着重总结了近几年来这类杂化材料在功能性研究上新的进展,并对今后研究的发展趋势进行了展望.     

铈离子氧化还原引发体系与铈离子引发接枝或嵌段共聚合研究的新进展

本文介绍Ce⁴⁺/酰胺引发体系;Ce⁴⁺/聚酰胺、带酰苯胺侧基的聚合物引发接枝共聚合;Ce⁴⁺/氨基甲酸酯引发体系;Ce⁴⁺/聚醚氨酯引发接枝共聚合;Ce⁴⁺/羰基化合物引发体系;Ce⁴⁺引发嵌段共聚合6个方面的研究新进展.     

可聚合的氧化还原引发体系

胺类具有还原性,可以与多种氧化剂构成氧化还原引发体系,胺类可产生自由基,引发乙烯基单体聚合.若乙烯基单体同时含有胺类基团,则这类自身还原性引发型单体在氧化剂存在的情况下既参与链引发又参与链增长,因此可以形成超支化聚合物.本文首先回顾了胺类氧化还原体系及其引发机理,然后总结自身还原性引发型单体分别与过氧化物、二芳酮、高氧...     

{4-[4-（对硝基苯甲酰基）苯硫基]苯}苯基碘鎓六氟磷酸盐的合成与光引发性能测试

紫外光固化反应按机理分为自由基固化、阳离子固化以及自由基-阳离子混杂固化.自由基-阳离子混杂固化是指在同一体系里同时通过自由基聚合和阳离子聚合而发生的固化[1].混杂聚合结合了各个聚合反应的优点,表现出很好的协同效应.杂化光引发剂被设计成既能引发自由基聚合又能引发阳离子聚合的光引发剂.据报道,目前常见的杂化光引发剂主要有碘鎓盐类和苯基膦二苯甲酮类[2].     

过硫酸盐和N,N,N′,N′-四甲基乙二胺体系引发烯类聚合机理的研究

<正> 过硫酸盐和N,N,N′,N′-四甲基乙二胺(TMEDA)体系用作烯类聚合的引发剂已有报道。本文报道该引发体系的反应机理。1.实验方法     

The determination of metals in organic compounds

Summary A comprehensive review of the methods available for the determination of metals in organic compounds has been made. The following metals have been considered:—sodium, potassium, lithium, rubidium, caesium, magnesium, calcium, barium, strontium, boron, thallium, silicon, germanium, antimony, bismuth, tin, lead, selenium, tellurium, silver, gold, osmium, platinum, copper, cadmium, zinc, mercury, vanadium, chromium, iron, cobalt, nickel, niobium, tantalum, rhenium, titanium, zirconium and uranium.

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Zusammenfassung Eine vollständige Übersicht über Methoden zur Bestimmung von Metallen in organischen Verbindungen wird gegeben. Für folgende Metalle werden Methoden beschrieben: Natrium, Kalium, Lithium, Rubidium, Cäsium, Magnesium, Calcium, Barium, Strontium, Bor, Thallium, Silicium, Germanium, Antimon, Wismut, Zinn, Blei, Selen, Tellur, Silber, Gold, Osmium, Platin, Kupfer, Cadmium, Zink, Quecksilber, Vanadium, Chrom, Eisen, Kobalt, Nickel, Niob, Tantal, Rhenium, Titan, Zirkonium und Uran.

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Résumé On donnait une revue complète des méthodes valables pour le dosage des métaux dans des substances organiques. Des méthodes sont décrites pour les métaux suivants: sodium, potassium, lithium, rubidium, caesium, magnésium, calcium, barium, strontium, bore, thallium, silicium, germanium, antimoine, bismuth, étain, plomb, sélénium, tellure, argent, or, osmium, platine, cuivre, cadmium, zinc, mercure, vanadium, chrome, fer, cobalt, nickel, niobe, tantale, rhenium, titane, zirconium et urane.

     

Elemental content in wheat products of Al-Qusim region, Saudi Arabia using the INAA technique

Wheat is one of the most grown crops in Saudi Arabia. It is grown in various regions of the country. Accurate knowledge of the elemental concentrations in wheat and its products (bran and flour) is of great importance from a nutritional point of view. Wheat samples were obtained from the Al-Qusim region, 300 km northwest of Riyadh, and analyzed. Up to 50 elements (Al, Sb, As, Ba, Br, Cd, Ca, Cs, Cl, Cr, Co, Cu, Ga, Au, Hf, In, I, Ir, Fe, Mg, Mn, Hg, Mo, Ni, K, Rb, Sc, Se, Ag, Na, Sr, Ta, Te, Th, Sn, Ti, W, U, V, Zn, Zr, Ce, Dy, Eu, La, Lu, Nd, Sm, Tb and Yb) were determined in the wheat products. It was observed that the elemental content of bran was much higher than that of white flour.     

Strategy for water analysis using ICP-MS

The developed strategy permits determination in three steps of sixty-seven elements using inductively coupled plasma mass spectrometry (ICP-MS). Sodium, Mg, Si, S, Cl, K, and Ca are determined in a first step; B, Al, P, Cr, Fe, Mn, Ni, Cu, Zn, As, Se, Ag, Cd, Sb, Ba, Hg, and Pb are determined in a second step; and Li, Be, Ti, V, Co, Ga, Ge, Br, Rb, Sr, Y, Zr, Nb, Mo, Sn, Te, I, Cs, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Pt, Au, Tl, Bi, Th, and U are analyzed in a third step. The figures of merit obtained are adequate to carry out water quality monitoring and other hydrochemical studies, such those based in the application of hydrochemical fingerprinting to water management.     

Traceability along the production chain of Italian tomato products on the basis of stable isotopes and mineral composition

The paper shows the variability of stable isotope ratios and mineral composition in tomato and derivatives along the production chain (juice, passata and paste) in order to evaluate the possibility of tracing their geographical origin. The ratios (13)C/(12)C, (15)N/(14)N, (18)O/(16)O, D/H, (34)S/(32)S and the content of Li, Be, B, Na, Mg, Al, P, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Rb, Sr, Y, Mo, Ag, Cd, Sn, Sb, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Tm, Yb, Ir, Tl, Pb, U and of nitrates, chlorides, sulphates and phosphates were measured by Isotope Ratio Mass Spectrometry, Inductively Coupled Plasma Mass Spectrometry and Ion Chromatography, respectively. The tomato products were from three Italian regions - Piedmont, Emilia Romagna, and Apulia. By applying linear discriminant analysis on 17 of these parameters (Gd, La, Tl, Eu, Cs, Ni, Cr, Co, δ(34)S, δ(15)N, Cd, K, Mg, δ(13)C, Mo, Rb and U) excellent discrimination among products from the three regions was achieved. Irrespective of the processing technology, over 95% of the samples were correctly reclassified in cross-validation into the production site. The use of these parameters will allow the development of analytical control procedures that can be used to check the geographical provenance of Italian tomatoes and products derived from them.     

Synthesis of 2‐Arylquinazolin‐4(3H)‐ones by N‐Aryl Benzamidines with Aromatic Carbonates

The reaction of N‐aryl benzamidines 1a , 1b , 1c , 1d , 1e , 1f , 1g , 1h , 1i , 1j , 1k , 1l , 1m , 1n with diphenyl carbonate 2a or ethyl phenyl carbonate 2b synthesized 2‐arylquinazolin‐4(3H)‐ones 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h , 3i , 3j , 3k , 3l , 3m , 3n in simple and safe process with good yields (71–90%). It was suggested that different electron‐donating substituent in N‐aryl benzamidines 1a , 1b , 1c , 1d , 1e , 1f , 1g , 1h , 1i , 1j , 1k , 1l , 1m , 1n afforded similar effect to the yields of 2‐arylquinazolin‐4(3H)‐ones 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h , 3i , 3j , 3k , 3l , 3m , 3n . In these reactions, N‐aryl benzamidines 1a , 1b , 1c , 1d , 1e , 1f , 1g , 1h , 1i , 1j , 1k , 1l , 1m , 1n built up intermediate compounds by nucleophilic addition to carbonates 2 to give annulation products 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h , 3i , 3j , 3k , 3l , 3m , 3n , following to cyclization involving the elimination of ethanol/phenol.     

Der Nachweis organischer Farbstoffe durch Mikrosublimation. II Besonderer Teil

Zusammenfassung Folgende organische Farbstoffe, die entweder als Pulver oder auch als Ausfärbung oder als Druck vorlagen, gaben kennzeichnende Sublimate:Indischgelb G, Dianilgelb G, die Hansagelbsorten 10 G, 5 G, 5 G transparent, 3 G, G, G transparent, GGR extra, GR, 3 R, Litholechtgelb RN, Helioechtgelb 6 GL, Litholechtorange RN, Permanentrot R extra, Litholechtscharlach RN (Hansarot B), Litholechtscharlach B, Permanentrot FRL, Autolrot BL, Autolrot RLP, Brillant-Indigo BASF, Indanthrengelb G, Indanthrenbraun G, Indanthrenblau RSN, Indanthrenviolett FFBN, Indanthrengelb 7 GK, Indanthrenbrillantorange GR, Indanthrenbrillantorange RK.

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Summary The following organic dyestuffs which were present either as powders or as dyed or printed material, gave characteristic sublimates:Indian yellow G, dianil yellow G, the 10 G, 5 G, 5 G transparent, 3 G, G, G transparent, GGR extra, GR, 3 R brands of Hansa yellow, lithol-fast yellow RN, helio-fast yellow 6 GL, lithol-fast orange RN, permanent red R extra, lithol-fast scarlet RN (Hansa red B), lithol-fast scarlet B, permanent red FRL, autol red BL, autol red RLP, brilliant indigo BASF, indanthrene yellow G, indanthrene brown G, indanthren blue RSN, indanthrene violet FFBN, indanthrene yellow 7 GK, indanthrene brilliant orange GR, indanthrene brilliant orange RK.

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Résumé Les pigments organiques suivants, qui étaient à notre disposition, soit comme poudre, soit comme colorisation ou comme impression, donnèrent des sublimés caractéristiques:Indischgelb G, Dianilgelb G, les sortes de Hansagelb 10 G, 5 G, 5 G transparent, 3 G, G, G transparent, GGR extra, GR, 3 R, Litholechtgelb RN, Helioechtgelb 6 GL, Litholechtorange RN, Permanentrot R extra, Litholechtscharlach RN (Hansarot B). Litholechtscharlach B, Permanentrot FRL, Autolrot BL, Autolrot RLP, Brillant-Indigo BASF, Indanthrengelb G, Indanthrenbraun G, Indanthrenblau RSN, Indanthrenviolett FFBN, Indanthrengelb 7 GK, Indanthrenbrillantorange GR, Indanthrenbrillantorange RK.

     

A systematic neutron activation analysis of peat from Burundi

Mean concentrations of Al, As, Au, Ba, Br, Ca, Ce, Cl, Co, Cr, Cs, Cu, Eu, Fe, Ga, Hf, Ho, I, K, La, Lu, Mg, Mn, Na, Pr, Rb, Sb, Sc, Sm, Sr, Ta, Tb, Ti, Th, V, W, Yb, and Zr, determined in 6 samples of peat from Burundi, were equal to 3911, 1.7, 0.025, 33, 21, 472, 14, 55, 4.2, 16, 0.43, 14, 0.27, 14675, 1. 2, 1.5, 0.09, 2.9, 203, 5.6, 0.29, 745, 20, 70, 1.5, 13, 2.1, 6.5, 0.8, 6, 0.4, 0.2, 2.9, 392, 15.7, 0.43, 0.09 and 101 ppm resp. The peat in Burundi contain approximately the same concentrations of elements as the peat in other countries. It is enriched in Br and depleted in Ca, K, Mn, Na, Sr and Yb.     

NAA and ICP analysis of obsidian from Central Europe and the Aegean: Source characterisation and provenance determination

INAA and ICPES are compared for their discriminative power in obsidian source characterisation. Geological samples from the Aegean and Carpathian sources were analysed for Na, Sc, Fe, Co, Rb, Sb, Cs, Ba, La, Ce, Sm, Eu, Tb, Yb, Lu, Hf, Ta, Th, U by INAA and for B, Na, Mg, Al, K, Ca, Sc, Ti, Mn, Fe, Zn, Y, Yr, Cs, Ba, La, Ce, Sm, Eu, Gd, Tb, Yb, Lu, Hf by two ICPES procedures. It is shown that all techniques work successfully, however, INAA is more efficient in the chemical discrimination of neighbouring sources.     

Systematic study of the solvent extraction of metal oxinates

The extraction of 32 metals (Be, Mg, Ca, Sr, Ba, Sc, La, Ti, Zr, Th, V, Nb, Cr, Mo, W, U, Mn, Fe, Co, Ni, Pd, Cu, Ag, Zn, Cd, Hg, Al, Ga, In, Tl, Pb and Bi) with oxine solution has been studied. The effects of pH, oxine concentration and water-soluble complexing agents (oxalic acid, tartaric acid, hydrocyanic acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid and 1,2-diaminocyclohexanetetraacetic acid) have been investigated. From these results the extraction constants and stability constants ot the metal complexes with the various complexing agents investigated have been calculated.