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...
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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...
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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: 712 | 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...
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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: 956 | 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: 751 | 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...
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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: 855 | Lượt tải: 0
Nghiên cứu lý thuyết đường phản ứng của gốc Methyl với Ethylamine - Nguyễn Hữu ThọThe mechanisms for the reaction of methyl radical with ethylamine were determined by the density functional theory using the atomic structures of the reactants, transition states and products optimized at the B3LYP/6-311++G(3df,2p) level of theory. Seven transition states were identified for the production of CH3CHNH2 + CH4 (TS1), CH3CH2NH + CH4...
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Tổng hợp và chuyển hóa hợp chất 3-Cyclohexyl-4- formylsydnone N-(2’,3’,4’,6’-Tetra-O-Acetyl-β-DGlucopyranosyl)Thiosemicarbazone từ CyclohexylamineThe thiosemicarbazone compound (6) contains sydnone ring, was synthesized from 4- formylsydnone (4), derived from cyclohexylamine (1), via four reaction series, by microwave irradiation method with 85%-yield. From the thiosemicarbazone compound (6), we performed cyclization reaction of thioure group with ethyl bromoacetate, in ethanol solvent an...
8 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 854 | Lượt tải: 0
