http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/1414 Các bài báo đăng trên các tạp chí quốc tế Tue, 19 May 2026 09:53:38 GMT 2026-05-19T09:53:38Z http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/1487 Photoluminescence properties of Co-doped ZnO nanorods synthesized by hydrothermal method Loan, T.T.; Long, N.V. Cobalt doped zinc oxide nanorods Zn1-xCoxO (x = 0.01, 0.10) have been synthesized by a hydrothermal process with Zn(NO 3)2, Co(NO3)2, NH4OH, CO(NH2)2 and C2H5OH at 150 °C for 1 h. Xray diffraction and scanning electron microscopy were used to characterize the crystalline structure, size and morphology of the samples. The photoluminescence (PL) and the PL excitation spectra of the nanorods were measured in the range of temperature from 15 K to room temperature. The PL spectra at low temperatures exhibit a group of ultraviolet narrow lines in the near-band-edge region of 3.0-3.4 eV and a very broad band peaked at 3.20 eV. The origin of the near-band-edge PL is interpreted as an emission from free excitons, neutral donor-bound excitons, radiative transitions from a donor to the valence band and donor-acceptor pairs. In particular, a group of emission lines in the red region of 1.8-1.9 eV have been revealed. These emission lines were assigned to the radiative transitions within the tetrahedral Co 2+ ions in the ZnO host crystal Thu, 01 Jan 2009 00:00:00 GMT http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/1487 2009-01-01T00:00:00Z http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/1482 First inventory of the water bugs (Heteroptera: Nepomorpha: Gerromorpha) of Langkawi Island, Kedah, Malaysia Zetel, H.; Tran, A.D. The first survey of the water bug fauna of Langkawi Island, Malaysia, yielded 55 species (five of which were identified only to the genus level) inhabiting various freshwater habitats, mangroves, and sea shores and belonging to 31 genera and eleven families; 17 species of ten genera from seven families belong to Nepomorpha, 38 species of 21 genera from four families to Gerromorpha. Three species are newly described here: Hydrotrephes langkawicus, new species (Helotrephidae), Strongylovelia narusei, new species, and Microvelia (Picaultia) minutissima, new species (both Veliidae). These new Veliidae have a more wide distribution than only in Langkawi Island: Strongylovelia narusei, new species is also known from Terengganu in peninsular Malaysia, and Microvelia (Picaultia) minutissima, new species is known from Selangor in peninsular Malaysia and from Singapore. Another nine species are recorded from Malaysia for the first time. Thu, 01 Jan 2009 00:00:00 GMT http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/1482 2009-01-01T00:00:00Z http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/1480 A modified Kain-Fritsch scheme and its application for the simulation of an extreme precipitation event in Vietnam Nguyen, Minh Truong; Tran, Tan Tien From 24 to 26 November 2004, an extreme heavy rainfall event occurred in the mountainous provinces of central Vietnam, resulting in severe flooding along local rivers. The Regional Atmospheric Modeling System, version 4.4, is used to simulate this event. In the present study, the convective parameterization scheme includes the original Kain-Fritsch scheme and a modified one in which a new diagnostic equation to compute updraft velocity, closure assumption, and trigger function are developed. These modifications take the vertical gradient of the Exner function perturbation into account, with an on-off coefficient to account for the role of the advective terms. According to the event simulations, the simulated precipitation shows that the modified scheme with the new trigger function gives much better results than the original one. Moreover, the interaction between convection and the larger-scale environment is much stronger near the midtroposphere where the return flow associated with lower-level winter monsoon originates. As a result, the modified scheme produces larger and deeper stratiform clouds and leads to a significant amount of resolvable precipitation. On the contrary, the resolvable precipitation is small when the original scheme is used. The improvement in the simulated precipitation is caused by a more explicit physical mechanism of the new trigger function and suggests that the trigger function needs to be developed along with other components of the scheme, such as closure assumption and cloud model, as a whole. The formalistic inclusion of the advective terms in the new equation gives almost no additional improvement of the simulated precipitation Thu, 01 Jan 2009 00:00:00 GMT http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/1480 2009-01-01T00:00:00Z http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/1476 Disruption of the AtREV3 gene causes hypersensitivity to ultraviolet B light and γ-rays in Arabidopsis: Implication of the presence of a translesion synthesis mechanism in plants Sakamoto, A; Vu, Thi Thuong Lan To investigate UV light response mechanisms in higher plants, we isolated a UV light-sensitive mutant, rev3-1, in Arabidopsis. The root growth of rev3-1 was inhibited after UV-B irradiation under both light and dark conditions. We found that chromosome 1 of rev3-1 was broken at a minimum of three points, causing chromosome inversion and translocation. A gene disrupted by this rearrangement encoded the catalytic subunit of DNA polymerase ζ (AtREV3), which is thought to be involved in translesion synthesis. The rev3-1 seedlings also were sensitive to γ-rays and mitomycin C, which are known to inhibit DNA replication. Incorporation of bromodeoxyuridine after UV-B irradiation was less in rev3-1 than in the wild type. These results indicate that UV light-damaged DNA interrupted DNA replication in the rev3-1 mutant, leading to the inhibition of cell division and root elongation Wed, 01 Jan 2003 00:00:00 GMT http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/1476 2003-01-01T00:00:00Z