Triterpenes from the roots of codonopsis pilosula - Trinh Thi ThuyThe EI-MS spectrum of 4 gave a mol peak at m/z 426 [M]+(18), indicating a same molecular formula (C30H50O) as 1. The APT and 13C-NMR spectra showed the presence of 30 carbons (CH3x8, CH2x10, CHx5, Cqx7). In comparison of the 1H- and 13C-NMR spectral data (table 2) with reported data [6], the structure of 4 was identified as D: B-friedoolean-...
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Modified binh thuan bentonite as an efficient and recyclable catalyst for the suzuki reaction between iodobenzene and phenylboronic acidThe effect of the reaction temperature was then investigated varying from 80oC to 120oC, using 0.2 mol% catalyst in DMF, and in the presence of K3PO4 as the base. It was decided to use 0.2 mol% instead of 0.5 mol% of the bentonite-Pd2+ catalyst for the reaction as the difference in reaction rates was not considerable. Experimental results sh...
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Antifungal constituents from the stems of dracaena cambodiana - Nguyen Hai DangThe connection of the sugars part to C-3 of the aglycone was confirmed by the correlation of an anomeric proton (δH 4.54) and C-3 position (δC 79.1) in the HMBC spectrum. This carbohydrate consisted of one disubstituted glucose and two terminal rhamnose moieties. The linkage positions of the sugars were determined by HMBC spectrum. According...
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Study on the Synthesis and Transformations of some Substituted 4-Methylquinolin-2(1H)-onesThis indicated that the 2-azido compounds did not exist, but instead of the fused heterocycle, namely tetrazolo[1,5-a]quinoline. The typical signal for all protons of the compound 5 appeared in 1H NMR spectra. Methyl group in the position 5 on the quinoline ring component had chemical shift in the upfield region at δ =~2.75 ppm (as singlet)....
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2D-Arrrays of Cu Nanodisks on Anodic Aluminum Oxide (AAO) Template for SERS Applications4. Conclusion 2D arrays of Cu nanodisks were fabricated in high quality by RF-sputtering Cu onto AAO templates, then removing the pore wall from them. The fabricated 2D array of Cu nanodisks showed different surface plasmon resonance peaks in the spectral range from 400 nm to 1400 nm. That is promising for SERS application. The enhancement effe...
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Synthesis and Electrochemical Properties of Fe2O3@C Composite - Bui Thi HangSEM image of Fe2O3/AB (Fig. 4) is quite different to that of Fe2O3@C (Fig. 2). It is impossible to distinguish Fe2O3 and AB particles. This suggests that Fe2O3 and AB was mixed relative uniformly. Comparison of the CV results of the Fe2O3@C electrode (Fig. 3) with those of Fe2O3/AB electrode at corresponding ratio of Fe2O3 and AB (Fig. 5) indica...
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Effect of Substituted Concentration on Structure and Magnetic Properties of Y3Fe5-XInxO12 - Vu Thi Hoai HuongIn summary, the present study has shown that Y3Fe5-xInxO12 (x = 0 ÷ 0.7) powders with size between 50 – 100 nm were fabricated using the sol-gel method. The single phase structural was observed for x as large as 0.6. At x = 0.7, a small amount of orthoferrite YFeO3 appears (~ 2%). The value of lattice constant increases with increasing x. Our re...
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Synthesis and Characterization of NiFe2O4/ZnO core-Shell Nanocomposites - Dinh Khac HuyIn summary, we have successfully synthesized NiFe2O4/ZnO core/shell nanoparticles by using a combination of hydrothermal and co-precipitation methods. In the sample, NiFe2O4 and ZnO phases were crystallized completely. Grains were observed to be a set of these phases. Magnetization of the core was enhanced significantly in the case that the NiFe...
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Molecular Dynamic Simulation of Large Model of Silica Liquid - Nguyen Thi Thanh HaIn this work, microstructure and dynamic properties of large model of silica liquid at pressures ranging from 0 to 20 GPa were investigated in detail. Results reveal that the structure of SiO2 liquid consists of structural units SiOx (x = 4, 5, 6) and OSiy (y = 2,3). At ambient, the number of SiO4 and OSi2 unit is domain. Upon compression, the f...
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Effective Excess Charge Density in Water Saturated Porous Media - Luong Duy ThanhIn this work, a model for the effective excess charge in a capillary QˆvR as well as in porous media REV Qˆv is developed for arbitrary pore scales. The results of QˆvR and QˆvREV as a function of the capillary radius, electrolyte concentration and permeability predicted from the obtained model are then compared with those from [19]. The compar...
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