• Tổng hợp chất màu xanh coban CoxMg1–xAl2O4 dùng trong gốm sứ bằng phương pháp pechiniTổng hợp chất màu xanh coban CoxMg1–xAl2O4 dùng trong gốm sứ bằng phương pháp pechini

    Tóm tắt. Bài báo trình bày quá trình tổng hợp chất màu xanh coban CoxMg1–xAl2O4 (x = 0,1÷0,9) theo phương pháp Pechini. Các đặc trưng của sản phẩm chất màu được xác định bởi phương pháp nhiễu xạ tia X (XRD), phân tích nhiệt (TG–DSC), hiển vi điện tử quét (SEM), cường độ màu đo trên hệ tọa độ CIE L*a*b*. Phối liệu chất màu CoxMg1–xAl2O4 được nung...

    pdf7 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 510 | Lượt tải: 0

  • Oxidation of carbon nanotubes using for Cu(II) adsorption from aqueous solutionOxidation of carbon nanotubes using for Cu(II) adsorption from aqueous solution

    Abstract. Carbon nanotubes (CNTs) synthesized via chemical vapour deposition without hydrogen were oxidized with 0.1 M potassium permanganate at 40 OC for 2 hours. The material exhibits a high CuII adsorption capacity from the aqueous solution. X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscope (SEM...

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  • Determination of luteolin from extracts of Helicteres hirsuta by HPLCDetermination of luteolin from extracts of Helicteres hirsuta by HPLC

    Abstract. High-performance liquid chromatography coupled with a photodiode array detector (HPLCDAD) has been reported to quantify isolated compounds. This work was designed, therefore, to develop an HPLC-DAD system to determine luteolin in the extract solutions from Helicteres hirsuta. Luteolin was analyzed on an RP-C18 column using a mobile phas...

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  • V2O5 nanowires: Hydrothermal synthesis and characterizationV2O5 nanowires: Hydrothermal synthesis and characterization

    Abstract. V2O5 nanowires were synthesized via controlled hydrothermal method. The morphology and nano-structure of synthesized samples were characterized by Field-Emission Scanning Electron Microscopy (FE-SEM), Raman spectroscopy and X-ray diffraction (XRD). The results showed that a pure crystalline phase of V2O5 was received. The average size...

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  • Chemical characteristics of groundwater in southeastern HanoiChemical characteristics of groundwater in southeastern Hanoi

    Abstract. To examine the occurrence and distribution of arsenic in groundwater, 137samples were collected from private wells in Southeastern Hanoi. According to the concentrations of major cations and anions, groundwater compositions vary from Ca-HCO3 to Na-HCO3 type. Groundwater has a very large range of chemical compositions and the spatial v...

    pdf8 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 541 | Lượt tải: 0

  • Survey of perfluoroalkyl substances concentration and their bioaccumulation in fish from two urban lakes, Ha Noi, VietnamSurvey of perfluoroalkyl substances concentration and their bioaccumulation in fish from two urban lakes, Ha Noi, Vietnam

    Abstract. Twelve perfluoroalkyl substances (PFASs) were investigated in fish samples collected in West Lake and Yen So Lake. Six PFASs including five perfluoroalkylcarboxylic acids (PFCAs) and only one perfluoroalkyl sulfonates acids (PFSAs) compounds were found in fish samples in both lakes. The concentration of long-chain carbon compounds suc...

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  • Using a central composite design to optimize the analytical method for simultaneous determination of choline, pantothenic acid, ascorbic acid, and niacin in food supplements by capillary zone electrophoresisUsing a central composite design to optimize the analytical method for simultaneous determination of choline, pantothenic acid, ascorbic acid, and niacin in food supplements by capillary zone electrophoresis

    Abstract. This study focused on using a central composite design (CCD) to optimize the analytical method for simultaneous determination of choline, pantothenic acid (vitamin B5), ascorbic acid (vitamin C), and niacin (vitamin B3) by capillary zone electrophoresis (CZE). The optimization process was designed with 30 experiments, including four f...

    pdf10 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 526 | Lượt tải: 0

  • The interaction between K[PtCl3(Isopropyl eugenoxyacetate)] with pyridine’s derivativesThe interaction between K[PtCl3(Isopropyl eugenoxyacetate)] with pyridine’s derivatives

    Abstract. The interactions of K[PtCl3(iPrEug)] (1) with either 2-aminopyridine (NH2Py) or 2-(aminomethyl)pyridine (NH2CH2Py) have been studied for the first time. The structures of obtained complexes, namely trans-[PtCl2(iPrEug)(NH2Py)] (2) and a mixture of [PtCl2(NH2CH2Py)] (3A) and trans-[PtCl2(NH2CH2Py)2] (3B), were determined by means of pl...

    pdf8 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 597 | Lượt tải: 0

  • Synthesis of some derivatives containing both benzothiazole and benzoxazin-3-oneSynthesis of some derivatives containing both benzothiazole and benzoxazin-3-one

    Abstract. Reaction of ethyl monochloro acetate and o-aminophenol derivatives gave two new benzo[b][1,4]oxazin-3(4H)-one containing benzo[d]thiazole ring with 2 methods in high yield. Structures of two benzo[b][1,4]oxazin-3(4H)-one based derivatives were elucidated with IR, 1D NMR, 2D NMR and MS spectra.

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  • A short, effective protocol for Shciff base synthesis using microwaveA short, effective protocol for Shciff base synthesis using microwave

    Abstract. Both nitration of vanillin and condensation of 5-nitrovanilllin with aniline derivatives were accelerated by using microwave oven. The nitration gave 5-nitrovanillin in 80% yield and the condensation gave twelve Schiff bases in excellent yield (80 - 97%) within short reaction time (4 - 10 min) along with other advantages like mild rea...

    pdf8 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 524 | Lượt tải: 0