Norisoprenoid, phenolic and steroidal constituents from mallotus luchenensis - Nguyen Huu Toan PhanThe 1H-NMR spectrum of 3 showed two singlet signals at δH 6.68 and 6.70 which were assigned to two aromatic protons. A broad singlet at δH 7.07 was assigned to a proton of a gallyol residue. The presence of an anomeric proton signal was upfield shifted to δH 6.38 (d, J = 2.0 Hz). The 13C-NMR and DEPT spectra of 3 showed the signals of three ...
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Characteristics and reducibility of nanosized La1-XCexCoO3 perovskites synthesized by reactive grinding - Nguyen Tien ThaoTwo ground La1-xCexCoO3 perovskites have been successfully synthesized and characterized. The solid solutions have rather high surface area and consist of elementary nanometric particles. The existence of small spaces between nanoparticles of perovskite makes these ground materials more porous. Under hydrogen atmosphere, the reduction of cob...
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Prediction of vapor-Liquid equilibria of binary mixtures using quantum calculations and activity coefficient modelsThe VLE data P-x-y of two binary systems methanol(1) - benzene(2) and toluene(1) - chlorobenzene(2) at T = 333.15 K and T = 343.15 K obtained over the pressure ranges from 0.4 to 0.7 bar and from 0.1 to 0.3 bar, respectively. For the three binary systems in this work the VLE data resulting from COSMO-SAC calculation were compared with exper...
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The blue shifts of the c-H and n-h bonds in the complexes of chx3 (x = f, cl, br) and hno: a theoretical study - Nguyễn Tiến TrungEach complex pairing HNO and CHX3 (X: F, Cl, Br) contains five separate minima on the potential energy surface. The binding energies obtained at the MP2/6-311++G(d,p) level are from 7 to 11 kJ.mol-1 with the BSSE correction and from 4 to 8 kJ.mol-1 with both the ZPE and BSSE corrections. The most stable are the complexes pairing CHBr3 with H...
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Monte carlo simulation of vapor - Liquid equilibria of hydrogen using ab initio intermolecular potentialsThe vapour-liquid phase equilibria and thermodynamic properties of the pure fluid hydrogen were calculated successfully with our developed computer simulation programs GEMC-NVT and GEMC-NPT using ab initio intermolecular pair potentials. The simulation results turn out to be in very good agreement with experimental data and with those from ...
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Synthesis of acyclovir as an antiherpes-Virus drug - Trần Quang HưngThis report describes a one-pot process for the preparation of acyclovir from guanine. Reacting N2,N9-diprotected guanine with 1- acetyl-2-acetylmethoxy-ethyleneglycol in present of phosphoric acid as catalyst provide ACV with high yield and good regioselectivity. Therefore, the purification was simple, inexpensive and conforming to pilot sc...
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Microwave-Assisted direct synthesis of some 5-alkyl- 2-amino-1,3,4-thiadiazoles - Nguyễn Đình ThanhThe separation of products out of the reaction mixture depended on carbon chain of aliphatic acid: in case of acetic acid and propionic acid, the reaction mixture was poured into ice-water and the obtained solution was neutralized by ammonia solution to pH 8; in remained cases, firsts, the reaction mixture was distilled by steam to remove u...
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Triterpenes and triterpene-Glycoside from the leaves of lawsonia inermis - Nguyễn Thị BìnhCompound 3 was obtained as needles. The 1H-NMR spectrum of 3 displayed 5 quaternary methyl groups at δ 1.43, 1.41, 1.24, 0.87, and 0.82 as singlets, and a tertiary methyl group at δ 0.95 as a doublet (J = 6.5 Hz), suggesting the presence of a ursane skeleton like 2. The olephilic proton at δ 5.30 as a broad singlet was assigned for a trisubs...
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Interaction second virial coefficients of dimer co-Co from new ab initio potential energy surfaceWe conclude that two our new ab initio 5- site pair potentials developed for the dimer COCO are reliable for predicting the thermodynamic properties. In coming work we will report the use of these ab initio 5-site pair petentials Eq. 3 and Eq. 4 for the Gibbs ensemble Monte Carlo (GEMC) simulation of vapor-liquid phase equilibria for pure liq...
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Comparative studies on the characteristic properties of the ground and conventional LaCo0.7Cu0.3O3 perovskiteThe characteristics and the reducibility of two Co-Cu based perovskites and a mixed Cu2O/LaCoO3 reference sample prepared by different preparative recipes have been investigated. X-ray diffraction results indicate the presence of both copper and cobalt sites in the perovskite framework. The ground samples have smaller crystal domains and thu...
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