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61.
Stabilization of M+ Ions (M = In, Tl) by Dibenzyldichlorogallate MCl reacts with (PhCH2)2GaCl to give M[(PhCH2)2GaCl2] [M = In ( 1 ), Tl ( 2 )]. 1 and 2 were characterized by NMR, IR and MS techniques. In addition, an X‐ray structure determination of 1 was performed. According to this, 1 consists of four‐membered In2Cl2 rings connected by weak In…Cl contacts (344 pm) along [010] to a coordination polymer. The In+ ion is coordinated by four In–Cl and two In‐aryl interactions. 相似文献
62.
Synthesis and Crystal Structure of [(PhCH2)2GaF(tBuNH2)]2 · 2 THF (PhCH2)2GaF reacts with tBuNH2 to the adduct [(PhCH2)2GaF(tBuNH2)] ( 1 ). 1 was characterized by NMR, IR and MS techniques. 1 can be recrystallized from THF forming crystals of [ 1 ]2 · 2 THF. According to an X-ray structure analysis [ 1 ]2 · 2 THF consists of dimers of 1 formed by hydrogen bridges. The THF molecules are coordinated to [ 1 ]2 by hydrogen bridges, too. 相似文献
63.
64.
Gidh AV Decker SR Vinzant TB Himmel ME Williford C 《Journal of chromatography. A》2006,1114(1):102-110
A method was developed using high-performance size exclusion liquid chromatography (HPSEC) with multi-angle laser light scattering (MALLS), quasi-elastic light scattering (QELS), interferometric refractometry (RI) and UV detection to characterize and monitor lignin. The combination proved very effective at tracking changes in molecular conformation of lignin molecules over time; i.e. changes in molecular weight distribution, radius of gyration, and hydrodynamic radius. Until this study, UV detection (280 nm) had been the primary lignin determination method for chromatography. Three different HPLC columns were used to study the effects of pH, flow conditions, and mobile phase compositions (dimethyl sulphoxide, water, 0.1M NaOH, and lithium bromide) on the chromatography of lignin. Since light scattering accuracy is highly dependent on solute concentration, both the UV and RI detectors were calibrated for use as concentration detectors. Shodex Asahipak GS-320 HQ column with 0.1M NaOH (pH 12.0) run at 0.5 ml/min was found to give the highest separation and most consistent recovery. The study also revealed that the lignin aggregated at pH below 8.5. This aggregation was detected only by MALLS and was not observed on UV or RI detectors. It is very important to take this loss in apparent concentration due to aggregation into consideration before collecting reliable depolymerization data. 相似文献
65.
Binks BP Clint JH Fletcher PD Lees TJ Taylor P 《Langmuir : the ACS journal of surfaces and colloids》2006,22(9):4100-4103
We have investigated the mechanism of the spontaneous growth of a gold nanoparticle film on a container wall when an aqueous dispersion of gold nanoparticles is shaken with an oil phase containing octadecylamine, as first described by Mayya and Sastry (Mayya, K. S.; Sastry, M. Langmuir 1999, 15, 1902.). Experimental evidence is described, which shows that the film growth is driven by the coalescence of particle-coated emulsion drops with the flat oil-water interface separating the oil and water phases. 相似文献
66.
Macrocyclization of synthetic peptides by thioesterase (TE) domains excised from nonribosomal peptide synthetases (NRPS) has been limited to peptides that contain TE-specific recognition elements. To alter substrate specificity of these enzymes by evolution efforts, macrocyclization has to be detected under high-throughput conditions. Here we describe a method to selectively detect cyclic peptides by fluorescence resonance energy transfer (FRET). Using this method, picomolar detection limits were easily realized, providing novel entry for kinetic studies of catalyzed macrocyclization. Application of this method also provides an ideal tool to track TE-mediated peptide cyclization in real time. The general utility of FRET-assisted detection of cyclopeptides was demonstrated for two cyclases, namely tyrocidine (Tyc) TE and calcium-dependent antibiotic (CDA) TE. For the latter cyclase, this approach was combined with site-directed affinity labeling, opening the possibility for high-throughput enzymatic screening. 相似文献
67.
We show that the fundamental methodology (and practice) of evaluation of derivative securities in continuous-time models is consistent with discrete-time theory, in which a derivative price is based on the principle that adding this security to the market does not create a violation of the basic economic principle: no riskless profit with zero investment. 相似文献
68.
Ohne Zusammenfassung 相似文献
69.
Dragendorff und Kopp 《Fresenius' Journal of Analytical Chemistry》1867,6(1):303-314
Ohne Zusammenfassung 相似文献
70.
Kopp M. I. Tour A. V. Yanovsky V. V. 《Journal of Experimental and Theoretical Physics》2018,127(6):1173-1196
Journal of Experimental and Theoretical Physics - We study the stability of a convective flow in a nonuniformly rotating plasma layer in an axially uniform magnetic field. The stationary and... 相似文献