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141.
A 3,4-O-bisacetal 2,6-di-O-benzyl protected thioglucoside is converted to the corresponding glucosyl triflate with 1-benzenesulfinyl piperidine and trifluoromethanesulfonic anhydride. The moderate to excellent β-selectivity exhibited with this glucosyl triflate with a range of alcohols is generally higher than that observed with the more electronically disarmed corresponding 3,4-O-carbonate, for which a possible reason is advanced. 相似文献
142.
143.
144.
K. N. Venkataraman K. Suresh Chandra 《Annals of the Institute of Statistical Mathematics》1984,36(1):101-118
Summary LetX(t) be a linear autoregressively generated explosive time series, with autoregressive coefficientsb
1,…,bq, and a constant termb
0, and an error term
; a0=1. Where ε(t),t≧1 are independent, Eε(t)=0, and Eε
2(t)=σ2 is positive and finite. In this paper two categories of
-consisent and asymptotically singularly normal estimators are proposed for (b
1,…,bq, b0) thus settling an open problem since the publication of the paper (Venkataraman [5]). Based on these estimators several additional
limit theorems based on estimated error residuals are proved. The parameter-free limit theorems of Spectral and Quenouille
types of this paper serve as asymptotic goodness of fit tests for the model generatingX(t). 相似文献
145.
The manganese and cobalt complexes [M(dtbp)2]n (M=Mn, Co; dtbp=di-tert-butyl phosphate), which exist as one-dimensional molecular wires, transform to [M(dtbp)2(bpy)2.2H2O]n by the addition of 4,4-bipyridine (bpy) at room temperature; the latter compounds form noninterpenetrating rectangular grid structures. 相似文献
146.
Several substrates have been employed in different oscillatory systems. A serious limitation is the low solubility in water. This has been overcome by employing aqueous-organic mixed media in the iodate-system as well as the uncatalyzed and catalyzed [Ce(III) or Ferroin] systems. The present paper deals with the study of fifteen new substrates in the bromate-Mn(II) oscillatory system employing aqueous-organic mixed media.
. . , - , (Ce(III) ), . -Mn(II) - .相似文献
147.
The manganese, cobalt, and cadmium complexes [M(dtbp)2]n (M = Mn (1) and Co 2) and [Cd(dtbp)2(H2O)]n (3) (dtbp = di-tert-butyl phosphate), which exist as one-dimensional molecular wires, transform to non-interpenetrating rectangular grids [M(dtbp)2(bpy)2.2H2O]n (M = Mn (4), Co (5), and Cd (6)) by the addition of 4,4-bipyridine (bpy) at room temperature. Products 4-6 have also been prepared by a room-temperature reaction or by solvothermal synthesis in methanol through a direct reaction between the metal acetate, di-tert-butyl phosphate, and 4,4'-bipyridine (bpy) in a 1:2:2 molar ratio. Single-crystal X-ray structure determination of 4-6 shows that these compounds are composed of octahedral transition metal ions woven into a two-dimensional grid structure with the help of bpy spacer ligands. The axial coordination sites at the metal are occupied by bulky unidentate dtbp ligands, which prevent any interpenetration of the individual grids. The change of reaction conditions from solvothermal to hydrothermal, for the attempted synthesis of a magnesium grid structure, however leads to the isolation of an organic phosphate [(H2bpy)(H2PO4)2] (7) and an inorganic phosphate [Mg(HPO4)(OH2)3] (8). Compound 7 can also be prepared quantitatively from a direct reaction between bpy and H3PO4. The new organic phosphate 7 is a unique example of a phosphate material with alternating layers of [H2bpy]2+ cations and [H2PO4]- anions that are held together by hydrogen bonds. Solid-state thermal decomposition of 4-6 produced the respective metaphosphate materials [M(PO3)2] (M = Mn (9), Co (10), and Cd (11)). All new metal-organic phosphates have been characterized by elemental analysis, thermal analysis (TGA, DTA, DSC), and IR and NMR spectroscopy. The metaphosphate ceramic materials were characterized by IR spectral and powder X-ray diffraction studies. 相似文献
148.
Abhishek Kumar Subhalakshmi Nagarajan Ke Yang Robinson Anandakathir Jagdeep Singh Ramaswamy Nagarajan 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(11):963-966
A novel, one step and simple methodology for the fabrication of submicron scale silver patterns is demonstrated. The photosensitivity of an organic silver salt has been utilized for this purpose of fabrication. The silver-organometallic compound is converted to metallic silver selectively in the illuminated regions. Surface morphology was studied by scanning electron microscopy (SEM). Energy dispersion spectroscopy (EDS) shows the presence of silver in the developed film. X-ray photoelectron spectroscopy (XPS) confirms the formation of metallic silver. Feature sizes of the order of 200 nm have been achieved using this technique. 相似文献
149.
Soumitra Satapathi Sethumadhavan Ravichandran Ravi Mosurkal Subhalakshmi Nagarajan Lian Li Ramaswamy Nagarajan 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(12):1061-1066
Resveratrol (3,5,4′ trihydroxy trans-stilbene) is a plant based phenolic compound. Enzymatic oligomerization of trans-resveratrol using horseradish peroxidase followed by characterization of the oligomer is presented. The oligomerization reaction was monitored using UV-Visible absorption and fluorescence spectroscopies. The oligomer exhibits strong two-photon-induced fluorescence. Computational modeling using spin-density calculations was performed to investigate the most probable reaction sites and the nature of products formed in the oligomerization process. 相似文献
150.