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第二代氨合成催化体系——钌系氨合成催化剂及其工业应用* 总被引:12,自引:0,他引:12
本文综述了第二代氨合成催化体系——钌系氨合成催化剂的研制、开发及工业应用情况。介绍了钌系氨合成催化剂的载体、促进剂、钌活性前身物对氨合成催化活性的影响。比较了钌系氨合成催化剂与铁系氨合成催化剂的反应机理与性能特点。新型氨合成催化工艺流程的成功开发为钌系氨合成催化剂的工业应用提供了有力的保障。 相似文献
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绿色合成,作为当代有机合成发展的一个重要学科前沿,已成为化学发展的一个方向。从催化剂、绿色溶剂、合成手段、合成方法、计算机辅助绿色合成等方面综述了近年来国内外实现绿色合成的有效途径,并对绿色合成的目标进行了探讨。参考文献35篇。 相似文献
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微量元素与疾病诊断治疗的研究现状及展望 总被引:8,自引:0,他引:8
对国内外微量元素与疾病的关系及其诊断治疗的研究现状及研究动向进行了综述,包括:微量元素与地方病、癌肿、心血管病、糖尿病、眼病、神经系统病等。参考文献72篇。 相似文献
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Wenbi Guan 《International journal of environmental analytical chemistry》2013,93(6):679-691
A QuEChERS (quick, easy, cheap, effective, rugged, and safe) method for the determination of benazolin-ethyl and quizalofop-p-ethyl in rape and soil by high-performance liquid chromatography-tandem mass spectrometry has been developed in this study. The residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil were determined with the developed method. The half-lives of benazolin-ethyl in rape straw and soil were 3.7–5.1 days and 14.3–26.3 days, respectively. The half-lives of quizalofop-p-ethyl in rape straw and soil were 5.0-6.1 days and 0.3–9.7 days, respectively. The residue of benazolin-ethyl and quizalofop-p-ethyl in rapeseed and soil were below the detection limit (i.e., 0.5?mg?kg?1, the maximum residue level of European Union for quizalofop-p-ethyl). 相似文献
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Ti-V基储氢合金在室温、常压下即可表现出良好的储氢特性,且质量储氢容量明显高于传统AB5型储氢合金,从而在氢气的精制和回收、运输和储存及热泵等方面有较早的应用。 此外,在混合气体分离、核反应堆中处理氢的同位素、镍氢电池及燃料电池负极材料等方面也得到了广泛的研究与关注。 基于目前Ti-V基储氢合金的研究现状,概述了该类合金的优势、限制性因素(包括成因)及改性手段。 此外,为了进一步理解Ti-V基合金储氢机理、构建合金组分与储氢特性之间的对应关系,本工作重点围绕Ti-V基储氢合金及其氢化物的结构、组分优化设计展开综述,并对其未来研究方向做出展望。 相似文献
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Prof. Inmaculada García‐Moreno Lu Wang Prof. Angel Costela Dr. Jorge Bañuelos Prof. Iñigo López Arbeloa Prof. Yi Xiao 《Chemphyschem》2012,13(17):3923-3931
Herein, we present the synthetic route and the photophysical, electrochemical as well as laser properties of novel red‐emitting boron‐dipyrromethenes (BODIPYs) bearing arylethyne moieties. Such functionality is added along the main axis of the chromophore leading to single‐ and double‐substituted derivatives. The relationship between the dye structure and the lasing properties is studied in detail with the help of the photophysical and electrochemical properties as well as quantum mechanical simulations. The asymmetric substitution of the parent dye induces inhomogeneities in the charge distribution, which leads to an overall loss of the fluorescence capacity, mainly in polar media. Such non‐radiative deactivation processes can be softened by decreasing the electron‐donor ability of the substituent or even avoided by symmetrical substitution. Thus, grafting of the arylethyne moieties at the longitudinal axis of the indacene core results in an effective strategy to develop red‐edge BODIPYs with highly efficient and photostable laser emission. 相似文献
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Peter Kis Eva Horvthov Elika Glov Andrea ev
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ov Veronika Antalov Elena Karniov Potock Vladimír Mastihuba Mria Mastihubov 《Molecules (Basel, Switzerland)》2021,26(24)
Tyrosol (T) and hydroxytyrosol (HOT) and their glycosides are promising candidates for applications in functional food products or in complementary therapy. A series of phenylethanoid glycofuranosides (PEGFs) were synthesized to compare some of their biochemical and biological activities with T and HOT. The optimization of glycosylation promoted by environmentally benign basic zinc carbonate was performed to prepare HOT α-L-arabino-, β-D-apio-, and β-D-ribofuranosides. T and HOT β-D-fructofuranosides, prepared by enzymatic transfructosylation of T and HOT, were also included in the comparative study. The antioxidant capacity and DNA-protective potential of T, HOT, and PEGFs on plasmid DNA were determined using cell-free assays. The DNA-damaging potential of the studied compounds for human hepatoma HepG2 cells and their DNA-protective potential on HepG2 cells against hydrogen peroxide were evaluated using the comet assay. Experiments revealed a spectrum of different activities of the studied compounds. HOT and HOT β-D-fructofuranoside appear to be the best-performing scavengers and protectants of plasmid DNA and HepG2 cells. T and T β-D-fructofuranoside display almost zero or low scavenging/antioxidant activity and protective effects on plasmid DNA or HepG2 cells. The results imply that especially HOT β-D-fructofuranoside and β-D-apiofuranoside could be considered as prospective molecules for the subsequent design of supplements with potential in food and health protection. 相似文献
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Kwiatkowski JS Leszczynski J Venkatraman R 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2000,56(14):1-2668
DFT(B3LYP) and MP2 calculations with the 6-311G(2d, 2p)-type basis set have been carried out for the prediction of molecular parameters (bond distances, bond angles, rotational constants, and dipole moments) and vibrational Raman and infrared spectra (harmonic wavenumbers, absolute intensities, Raman scattering activities, and depolarization ratios) of bromochlorofluoromethane (HCBrCIF) and its silicon and germanium analogs (HSiBrClF and HGeBrCIF). The predicted geometry and vibrational Raman and infrared spectra of HCBrClF agree well with the available experimental data for this molecule and their deuterated derivatives. This agreement allows one to believe that the predicted molecular parameters and vibrational spectra of HSiBrClF, HGeBrClF, and their deuterated derivatives will guide their future experimental studies. 相似文献
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K. J. Jalkanen Julian D. Gale P. R. Lassen L. Hemmingsen A. Rodarte I. M. Degtyarenko R. M. Nieminen S. Brøgger Christensen M. Knapp-Mohammady S. Suhai 《Theoretical chemistry accounts》2008,119(1-3):177-190
In this work we present the experimental and theoretical vibrational absorption (VA) and the theoretical vibrational circular
dichroism (VCD) spectra for aframodial. In addition, we present the theoretical VA and VCD spectra for the diasteriomers of
aframodial. Aframodial has four chiral centers and hence has 24 = 16 diasteriomers, which occur in eight pairs of enantiomers. In addition to the four chiral centers, there is an additional
chirality due to the helicity of the entire molecule, which we show by presenting 12 configurations of the 5S,8S,9R,10S enantiomer
of aframodial. The VCD spectra for the diasteriomers and the 12 configurations of one enantiomer are shown to be very sensitive
not only to the local stereochemistry at each chiral center, but in addition, to the helicity of the entire molecule. Here
one must be careful in analyzing the signs of the VCD bands due to the ‘non-chiral’ chromophores in the molecule, since one
has two contributions; one due to the inherent chirality at the four chiral centers, and one due to the chirality of the side
chain groups in specific conformers, that is, its helicity. Theoretical simulations for various levels of theory are compared
to the experimental VA recorded to date. The VCD spectra simulations are presented, but no experimental VCD and Raman spectra
have been reported to date, though some preliminary VCD measurements have been made in Stephens’ lab in Los Angeles. The flexible
side chain is proposed to be responsible for the small size of the VCD spectra of this molecule, even though the chiral part
of the molecule is very rigid and has four chiral centers. In addition to VCD and Raman measurements, Raman optical activity
(ROA) measurements would be very enlightening, as in many cases bands which are weak in both the VA and VCD, may be large
in the Raman and/or ROA spectra. The feasibility of using vibrational spectroscopy to monitor biological structure, function
and activity is a worthy goal, but this work shows that a careful theoretical analysis is also required, if one is to fully
utilize and understand the experimental results. The reliability, reproduceability and uniqueness of the vibrational spectroscopic
experiments and the information which can be gained from them is discussed, as well as the details of the computation of VA,
VCD and Raman (and ROA) spectroscopy for molecules of the complexity of aframodial, which have multiple chiral centers and
flexible side chains.
Festschrift in Honor of Philip J. Stephens’ 65th Birthday. 相似文献
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Charles Manzi-Nshuti 《Polymer Degradation and Stability》2007,92(10):1803-1812
In this work, ferrocene- and ferrocenium-containing salts were employed to modify montmorillonite. X-ray measurements show an increase in the interlayer spacing upon clay modification, which means that the larger and more organophilic cations were inserted into the gallery space of montmorillonite. Attempts to prepare nanocomposites of polystyrene and ethylene vinyl acetate copolymers lead to immiscible systems; the morphology of these systems was elucidated with TEM, XRD and cone calorimetry. The thermal stability of the composites is greater than that of the virgin polymer. 相似文献