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Kết quả bước đầu về hàm lượng các kim loại nặng trong nước sông hồng tại trạm thủy văn Sơn Tây - Đặng Thị HàThis study is based on the experimental results obtained from analysis of suspended and dissolved heavy metal concentrations (V, Cr, Co, Ni, Cu, Zn, As, Mo, Cd, Sb, Pb and Th) in the Red River at the SonTay station during 2011. The results showed that for the dissolved phase, heavy metal concentrations were relatively stable, whatever the water ...
8 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 949 | Lượt tải: 0
Hàm lượng kim loại nặng (hg, cd, pb, cr) trong các loài động vật hai mảnh vỏ ở một số cửa sông tại khu vực miền Trung,Việt Nam - Nguyễn Văn KhánhHeavy metal contents in Corbicula subsulcata, Meretrix meretrix, Perna viridis and Saccostrea sp. from estuaries in Central Vietnam, including Thuan An, Han river, Dai, Sa Can, Song Kon - Thi Nai lagoon were higher than maximum permissible limit, compared to QCVN 8:2- 2011/BYT for Hg, Cd and Pb and Metallic Contamination Regulations of the Publi...
7 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 856 | Lượt tải: 0
Cyclic behavior and energy approach of the fatigue of shape memory alloysIn the first part of this paper a model capable of simulating several phenomena associated with shape memory materials subjected to cyclic loading is presented. The modeling process is based on a simple observation: on the macroscopic level, SMA training can be interpreted as a thermomechanically-induced transition from an unstable, virgin mate...
20 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 909 | Lượt tải: 0
Structure and properties of double perovskite system la2co1−xfexmno6 - Pham The TanThe magnetization versus field measured at 20 K is given in Fig. 3. The inset in Fig. 3 illustrates the possible spin exchanges mediated through oxygen 2p orbitals between t2g and eg electrons of the metals according to Ref. [1] (Kanamori-Goodenough rule). The FM state which prevails below the Curie temperature is a result of a half-fill M(t...
5 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 817 | Lượt tải: 0
Current - Voltage characteristics of polymethylthiophene/tio2 nanocomposite cellsThin films of polymethylthiophene/titanium oxide nanocomposites were prepared by electrophoretic deposition. Obtained films were applicable for the investigation of photoelectrochemical and electrical properties of the nanocomposite. The electrochemical behaviour of the composite layers was investigated by cyclic voltammetry. The reversible a...
6 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 747 | Lượt tải: 0
Ab initio calculation of the intermolecular potential and prediction of second virial coefficients for dimer H2-H2The second virial coefficients of hydrogen obtained from the two potential functions Eq. 3 and Eq. 4 are very close to experimental data, as described in Fig 3. The discrepancies between them are insignificant. The second virial coefficients are generated almost within the uncertainties of the experimental measurements. The first-order quant...
6 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 929 | Lượt tải: 0
Study on the chemistry and antimicrobial activity of psychotria reevesii wall. (rubiaceae)Compound 2 was isolated as white needles. The molecular formula of 2 was determined to be 444 (M+., C27H28O4N2) by EIMS spectrum. The IR spectrum showed the presence of amide (max 3315, 1661, and 1630 cm-1) and ester (max 1726 and 1261 cm-1) functional groups, and aromatic rings (max 1600, 1532, and 1450 cm-1). The 1H- and 13C-NMR spectro...
6 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 1046 | Lượt tải: 0
Nghiên cứu lý thuyết sự tạo thành Metan trong phản ứng của gốc Metyl với Propanol-2 - Nguyễn Hữu ThọCác đường phản ứng giữa gốc tự do metyl và phân tử propanol-2 đã được khảo sát một cách đầy đủ bởi phương pháp phiếm hàm mật độ có độ tin cậy cao B3LYP/6-311++G(3df,2p). Hàng rào năng lượng của bảy đường phản ứng R1÷ R7 lần lượt là 7,66; 8,86; 13,94; 38,87; 45,82; 49,82; 69,66 kcal/mol. Có ba đường phản ứng tách có thể tạo ra sản phẩm metan ...
9 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 793 | Lượt tải: 0
Preliminary assessment of organochlorine pesticide residues in the sediment from several estuaries and tam giang - Cau hai lagoon, Thua Thien Hue, 20051. Most of organo-chlorine pesticide concentrations in the sediment from the estuaries in Thua Thien Hue were exceeded the Sediment Criteria for Human Health Bioaccumulation Level from US EPA 1999 criteria and Canadian EQG 2002 criteria. Some of them even exceeded the Wildlife Bioaccumulation Criteria. There are some environment problems th...
6 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 1092 | Lượt tải: 0
Fe-MCM-22 zeolite: synthesis and study about the states of iron - Ngô Thị Thuận1. Successful synthesis of Fe-MCM-22 under hydrothermal condition using HMI template was confirmed by XRD. 2. As-synthesized zeolite has relatively high surface area, 286 m2/g (BET). Its white colour and a band at 950 cm-1 partially overshadowed by the strong absorption centered at 1100 cm-1 in IR spectra suggested a location of iron specie...
5 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 930 | Lượt tải: 0
