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41.
甲醇与乙醇一步合成异丁醛用CuO-ZnO/Al2O3催化剂 总被引:20,自引:0,他引:20
在CuO-ZnO/Al2O3催化剂上,甲醇与乙醇在常压和210 ̄360℃温度下一步反应合成异丁醛。利用正交设计方法,研究了CuO-ZnO/Al2O3体系催化剂组成和制备条件等因素对催化剂催化性能的影响。结果表明,催化剂中CuO含量对催化剂的催化活性影响最大,而ZnO含量则主要影响催化剂对异丁醛的选择性。催化剂制备条件,如沉淀温度、陈化时间等,也不同程度也影响催化剂的催化性能。XRD和BET表征结果 相似文献
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ADSORPTION OF 2,4-DICHLOROBENZOXYACETIC ACID ONTO HYPERCROSSLINKED RESIN MODIFIED BY PHENOLIC HYDROXYL GROUP (AM-1) 总被引:2,自引:0,他引:2
INTRODUCTIONAdsorption has been considered to be the best available technology for removing organics from water in the USSafe Drinking Water Act[1]. Due to many drawbacks of activated carbon[2-7], the most widely used adsorbent,hypercrosslinked polymeric adsorbents developed by Tsyurupa and Davankov[8] have been increasingly viewedas an alternative to activated carbon for selective removal of specific organic substances from contaminatedwater[9-12], and series of researches have been do… 相似文献
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JunZhou Yong-zhiQiu Xiao-pengZang Chang-wangPan QiangChen JianShen Si-congLin 《高分子科学》2005,(1):93-102
N,N-dimethyl-N-methacryloyloxyethyl-N-carboxyethyl ammonium (DMMCA) was graft-copolymerized onto the surface of segmented poly(ether urethane) (SPEU) and PE film. The carboxybetaine structure on SPEU and PE film surfaces was confirmed by ATR-FTIR, XPS and water contact angle measurements. Through the experiments with platelet adhesion and protein adhesion assay in vitro, the two materials studied, including poly-DMMCA gel, all show excellent nonthrombogenicity. This confirms once again that the zwitterionic molecular structure on the surfaces of materials is essential for improving their nonthrombogenicity and biocompatibility. 相似文献
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本文利用含氢有机硅化合物与含双键的氨基酸酯的加成反应,合成了5种新的有机硅氨基酸衍生物。介绍了一种合成N-烷基取代氨基酸酯的新方法。对新化合物进行了元素和光谱分析鉴定。 相似文献
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S. G. Wang Y.X. Qiu E. Neumann H. J. Deiseroth W. H. Eugen Schwarz 《无机化学与普通化学杂志》2003,629(10):1718-1730
About 60 molecular species composed of up to 10 mercury atoms and of oxygen atoms and/or of some other elements or groups (such as halogen, OH2, OH, H, alkali, NO3) have been investigated quantum chemically. Different density functional approaches and the ab initio SCF‐MP2 method were applied, comparing different basis sets and different atomic core sizes. It is important not to treat the Hg 5s, p, d as inactive core shells, and to use sufficiently many polarization functions. The shape of the 〉O‐Hg‐Hg‐O〈 units is not favorable concerning the formation of lattices composed of HgI, O and OH only. Despite its bulkiness, the OHgHgO units can easily come into contact with each other and then disproportionate. This is prevented in the so‐called ternary M‐HgI oxides by the embedded oxometallate (oxoacidic) anions. Furthermore, the HgI and HgII oxide bond energies are less favorable towards the stability of HgI oxo compounds, as compared to Hg halidic or oxoacidic compounds. Both points are not promising concerning the search for HgI oxides/hydroxides, although the preparation of such compounds, including spacer groups, by topochemical reactions can still not be excluded. So far, experimental efforts towards the synthesis of such a new class of compounds have only demonstrated that HgII is strictly preferred over HgI in the formation of solids of binary Hg‐O or ternary A‐Hg‐O composition (A = electropositive metal such as alkali, in contrast to M = transition or semi‐metal). This is so even if compounds containing ‘electron rich Hgδ— atoms’ (i.e. A‐Hg amalgams) are oxidized under mild conditions. 相似文献
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A vinyl monomer having an electron-donating moiety, p-(N,N-dimethylamino)styrenc (DMAS),was synthesized. It was combined with benzoyl peroxide (BPO) to form a redox initiation system to initiatethe polymerization of methyl methacrylate (MMA). UV spectra measurements show that DMAS enters thePMMA chain as well. Both DMAS and its polymer P(DMAS) display strong fluorescence, and thefluorescence can be quenched by electron-deficient compounds such as methacrylonitrile, fumaronitrile andmethyl methacrylate etc. Moreover, DMAS can also form charge transfer complex (CTC) with strongelectron acceptors such as tetracyanoethylene (TCNE). The difference between the photochemical propertiesof DMAS and P(DMAS) were explained in terms of molecular structure change and polymer conformationeffect in solution. In addition, the CTC and exciplex formation of DMAS or P(DMAS) with C_(60) were alsostudied. 相似文献
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Yanyan Zhao Ole Tietz Wei-Li Kuan Abdul K. Haji-Dheere Stephen Thompson Benjamin Vallin Elisabetta Ronchi Gergely Tth David Klenerman Franklin I. Aigbirhio 《Chemical science》2020,11(18):4773
Soluble forms of aggregated tau misfolded protein, generally termed oligomers, are considered to be the most toxic species of the different assembly states that are the pathological components of neurodegenerative disorders. Therefore, a critical biomedical need exists for imaging probes that can identify and quantify them. We have designed and synthesized a novel fluorescent probe, pTP-TFE for which binding and selectivity profiles towards aggregated tau and Aβ proteins were assessed. Our results have shown pTP-TFE to be selective for early forms of soluble tau aggregates, with high affinity of dissociation constants (Kd) = 66 nM, and tenfold selectivity over mature tau fibrils. Furthermore, we found that pTP-TFE is selective for tau over Aβ aggregates and had good cell permeability. This selectivity of pTP-TFE towards early forms of aggregated tau protein ex vivo was also supported with studies on human brain tissue containing tau and Aβ pathology. To the best of our knowledge, this is the first fluorescent molecule to be reported to have this form of selectivity profile, which suggests that pTP-TFE is a unique probe candidate for imaging-based detection of early stages of Alzheimer''s disease and other tauopathies. pTP-TFE imaging probe can distinguish soluble tau aggregated proteins from other aggregated proteins enabling earlier detection of neurodegenerative diseases. 相似文献