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71.
JM Pakarinen H Moisio S Holopainen P Vainiotalo 《Rapid communications in mass spectrometry : RCM》1999,13(14):1485-1490
2-Methoxyethanol chemical ionization of amines, carboxylic acids and amino acids has been found to produce numerous adduct ions. The most intense adduct ions for amines are [M + H](+) and [M + 77](+), for carboxylic acids [M + 27](+), [M + 59](+) and [M + 77](+), and for amino acids [M + H](+), [M + 13](+), [M + 27](+) and [M + 77](+). Either the adduct ion [M + H](+) or [M + 77](+) was the most abundant ion found for amino acids. The proton affinities of amino acids are noticed to control the formation of the [M + H](+) and [M + 77](+) ions. The relative abundance of [M + 13](+) and [M + 27](+) ions varied for different amino acids being most intense for phenylalanine and aspartic acid. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
72.
Carolien M. Vis Dr. Anne-Eva Nieuwelink Prof. Dr. Bert M. Weckhuysen Prof. Dr. Pieter C. A. Bruijnincx 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(66):15099-15102
Pickering emulsions (PEs), emulsions stabilized by solid particles, have shown to be a versatile tool for biphasic catalysis. Here, we report a droplet microfluidic approach for flow PE (FPE) catalysis, further expanding the possibilities for PE catalysis beyond standard batch PE reactions. This microreactor allowed for the inline analysis of the catalytic process with in situ Raman spectroscopy, as demonstrated for the acid-catalyzed deacetalization of benzaldehyde dimethyl acetal to form benzaldehyde. Furthermore, the use of the FPE system showed a nine fold improvement in yield compared to the simple biphasic flow system (FBS), highlighting the advantage of emulsification. Finally, FPE allowed an antagonistic set of reactions, the deacetalization–Knoevenagel condensation, which proved less efficient in FBS due to rapid acid-base quenching. The droplet microfluidic system thus offers a versatile new extension of PE catalysis. 相似文献
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R. Adam Rebeles P. Van den Winkel A. Hermanne L. De Vis R. Waegeneer 《Journal of Radioanalytical and Nuclear Chemistry》2010,286(3):655-659
A homemade modular PC-controlled radiochemistry system, used to separate the no-carrier-added 64Cu from irradiated electroplated solid cyclotron target 64Ni layers was developed. Upon irradiation the target layer is dissolved in diluted nitric acid, followed by selective liquid–liquid
extraction of the 64Cu. The final purification step is achieved making use of an anion exchange column. All the separation procedures can be carried
out remote-controlled with a minimized risk of operator errors within less than 2 h, with excellent processing yield (>95%). 相似文献
75.
本文报导了采用氩离子激光器来泵浦Rr ̄(3+):YLF晶体,应用声光调制器实现了主动锁模;同时应用振动─高反射平面镜也实现了被动锁模,两种锁模均得到了ps光脉冲。据作者了解这是这种晶体材料的第一次锁模运转。 相似文献
76.
R. D. Vis K. J. Wiederspahn H. Verheul 《Journal of Radioanalytical and Nuclear Chemistry》1978,45(2):407-416
Proton induced X-ray emission (PIXE) is used in an attempt to identify glass samples with the aid to determine, trace element
concentrations. The elements Na and A1 are simultaneously determined using the (p, p' γ) nuclear reaction. The preparation
of very thin and homogeneous glass targets is discussed and a procedure is described to obtain an accurate equipment calinration,
checked afterwards with NBS bovine liver. Results are given for 11 different glass samples. 相似文献
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Alves GA Amato S Anjos JC Appel JA Astorga J Bracker SB Cremaldi LM Dagenhart WD Darling CL Dixon RL Errede D Fenker HC Gay C Green DR Jedicke R Karchin PE Kennedy C Kwan S Lueking LH de Mello Neto JR Metheny J Milburn RH de Miranda JM da Motta Filho H Napier A Passmore D Rafatian A dos Reis AC Ross WR Santoro AF Sheaff M Souza MH Spalding WJ Stoughton C Streetman ME Summers DJ Takach SF Wallace A Wu Z 《Physical review letters》1996,77(12):2392-2395
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