Chemical constituents of the lichen Dermatocarpon luridum and pKa value of isolated mycosporine - Nguyen Thi Thu TramIn the previous work, the authors have shown that mycosporine 1 has a strong absorption at 310 nm in the region of UVB (290-320 nm) with high ε 12540 M-1.cm-1 suggesting the potential application as a natural photoprotectant [4]. Such compound contains one acido-basic site, however, its dissociation constant has never been published so far. ...
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Effect of chromium substituted on structural and magnetic characterization lithium ferrite nanoparticles - Nguyen Thi LanLi0.5Fe2.5-xCrxO4 spinel nanoparticles (x = 0, 0.5, 0.75, 1 and 1.25) were obtained by using a citrate sol-gel method. The samples have the cubic spinel structure at room temperature with the lattice constant a slightly decreases with increasing Cr content. The good crystallinity single domain particles has average diameter 22-30 nm. The core...
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Mg-Al-MoO4 layered double hydroxides used as catalysts for the oxidation of styrene - Nguyen Tien ThaoMoreover, the catalytic activity does not only vary with the reaction temperatures but also depends on the oxidant nature. In practice, Figure 5A presents the different catalytic activity as different oxidants are introduced into the styrene reactant. It is worthily noted that three examined oxidants all express the good ability to oxidize st...
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Synthesis of new hemiasterlin derivatives with α,β-Unsaturated carbonyl-thiophene groups in fragment ATo a cooled (0 oC) solution of 14a (50 mg, 0.102 mmol) in 2 mL MeOH/H2O (2:1) was added LiOH (25 mg, 1.02 mmol). The cooling bath was removed, and the resulting mixture was stirred at room temperature for 10 h. The solvent was removed in vacuum and the residue was dissolved in a small amount of H2O. The aqueous solution was cooled to 0 oC, a...
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Thermokinetic study of the isomerization of isocyanic acid - Nguyen Huu ThoThere are eight existent feasible isomers on the potential energy surface [H, N, C, O], in which isocyanic acid and cyanic acid are the most stable isomers. The HNOC isomer contains a N O unstable donor – acceptor bond is intermediate complex forming CO, NH products. Isomerizations are difficult to occur at normal temperature and pressure co...
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Degradation of tartrazine dye from aqueous solution by heterogeneous fenton-Like reaction on Fe2O3/SiO2 composite - Vu Van TuIn this study, the Fe2O3/SiO2 composite has been successfully prepared via a simple impregnation method. The Fe2O3 with small particle size was highly dispersed on silica and exhibited excellent efficiency for the Fenton degradation of tartrazine, 98.5 % in 80 min. It was much higher than that of physic mixture Fe2O3/SiO2, and other materials...
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The effect of combustion temperature to low-Tar gas production using oxygen-enriched air - Dinh Quoc VietThe effects of combustion temperature on the tar formation and the syngas composition using oxygenenriched air were studied experimentally in a pilot scale two-stage biomass gasification system with different oxygen-enriched air. In this study, the oxygen level in the gasifying agent was increased from 21 to 42 vol.%. The experiments of severa...
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A quantum chemical computation insight into the donor-Acceptor bond interaction of silver complexes with tetrylene - Tran Duc SyDFT calculations find that the equilibrium structures of the Ag-NHE show major differences in the bonded orientation of NHPb ligand in Ag-NHPb compared with NHE ligands the slighter homologues Ag-NHE (E= C-Sn). The BDE results show that the Ag-carbene bond in Ag-NHC is very strong bond and decreases from the slighter to the heavier homologue...
8 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 778 | Lượt tải: 0![Preparation of some new benzo[d]thiazole derivatives - Duong Quoc Hoan](https://s2.tai-lieu.com/pwz9k16xr4jr01yq7rzg033izykdsbez/thumb/2020/12/03/preparation-of-some-new-benzodthiazole-derivatives-duong-quo_QDDbheuZKr.jpg)
Preparation of some new benzo[d]thiazole derivatives - Duong Quoc HoanThe most difficult assignment was identification of C13/C19 and H13/H9. Fortunately, it was easily to find H14 that had an HMBC cross-peak with H9. Therefore, H13 and C13 were identified and so on. Other assignments were shown in the figure 2. Finally, compounds 3, 4, 5 and 6 were recorded for mass spectroscopy. MS spectrum of compound 3 ind...
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Membrane distillation for seawater desalination applications in vietnam: potential and challenges - Duong Cong HungSeawater desalination using membrane distillation (MD) can be a pragmatic solution to fresh water scarcity in Vietnam. As a hybrid desalination process, MD inherits attributes of both pressure-driven membrane separation and thermal distillation. These attributes include process modularization, low susceptibility to feed osmotic pressure, low ris...
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