A Preliminary Study on the Occurrence of Pharmaceutically Active Compounds in Hospital Wastewater and Surface Water in Hanoi,Vietnam          下载免费PDF全文

Ngoc Han Tran  Taro Urase  Thi Thao Ta 《洁净——土壤、空气、水》2014,42(3):267-275

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Recent climatic trends and linkages to river discharge in Central Vietnam   总被引：1，自引：0，他引：1       下载免费PDF全文

Maxime Souvignet  Patrick Laux  Jim Freer  Hannah Cloke  Dang Quang Thinh  Tran Thuc  Johannes Cullmann  Alexandra Nauditt  Wolfgang‐Albert Flügel  Harald Kunstmann  Lars Ribbe 《水文研究》2014,28(4):1587-1601

In this study, change in rainfall, temperature and river discharge are analysed over the last three decades in Central Vietnam. Trends and rainfall indices are evaluated using non‐parametric tests at different temporal levels. To overcome the sparse locally available network, the high resolution APHRODITE gridded dataset is used in addition to the existing rain gauges. Finally, existing linkages between discharge changes and trends in rainfall and temperature are explored. Results are indicative of an intensification of rainfall (+15%/decade), with more extreme and longer events. A significant increase in winter rainfall and a decrease in consecutive dry days provides strong evidence for a lengthening wet season in Central Vietnam. In addition, trends based on APHRODITE suggest a strong orographic signal in winter and annual trends. These results underline the local variability in the impacts of climatic change at the global scale. Consequently, it is important that change detection investigations are conducted at the local scale. A very weak signal is detected in the trend of minimum temperature (+0.2°C/decade). River discharge trends show an increase in mean discharge (31 to 35%/decade) over the last decades. Between 54 and 74% of this increase is explained by the increase in precipitation. The maximum discharge also responds significantly to precipitation changes leading to a lengthened wet season and an increase in extreme rainfall events. Such trends can be linked with a likely increase in floods in Central Vietnam, which is important for future adaptation planning and management and flood preparedness in the region. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Seismic retroftting of RC columns with RC jackets and wing walls with different structural details     

Shuenn-Yih Chang  Ting-Wei Chen  Ngoc-Cuong Tran  Wen-I Liao 《地震工程与工程振动(英文版)》2014,13(2):279-292

An original reinforced concrete(RC) column and four strengthened specimens, two with RC jackets and two with wing walls, were tested in this study. The original column specimen was designed to comply with older(pre-1999) design standards so that the usual detailing defi ciencies in existing school buildings in Taiwan could be simulated. Two different structural details were chosen to fabricate the full-scale specimens for each retrofi tting technique. The study confi rmed that either RC jacketing or the installation of wing walls with two different structural details can effectively improve the stiffness and strength of an existing column. RC jacketing shows a better improvement in energy dissipation and ductility when compared to the columns with wing walls installed. This is because the two RC jacketed columns experienced a fl exural failure, while a shear failure was found in the two columns with the wing walls installed, and thus led to a drastic decrease of the maximum lateral strengths and ductility. Since many factors may affect the installation of a post-installed anchor, it is better to use standard hooks to replace post-installed anchors in some specifi c points when using RC jacketing or installing wing walls.  相似文献   

An Improved Formula of Fundamental Resonance Frequency of a Layered Half-Space Model Used in H/V Ratio Technique     

Tran Thanh Tuan  Pham Chi Vinh  Matthias Ohrnberger  Peter Malischewsky  Abdelkrim Aoudia 《Pure and Applied Geophysics》2016,173(8):2803-2812

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Incorporation of Heavy Metals Bioavailability into Risk Characterization     

Hyerim Ryu  Jae Shik Chung  Taekwoo Nam  Hee Sun Moon  Kyoungphile Nam 《洁净——土壤、空气、水》2010,38(10)

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Estimation of efficiency of the modern and planning optimal network of seismic stations within the Vietnam territory     

V. Yu. Burmin  Ngo Thi Lu  Tran Viet Phuong 《Seismic Instruments》2010,46(1):27-37

Efficiency of the modern network of seismological observations in Vietnam is estimated, and an optimal design of planning network, consisted of 14 seismic stations is proposed. At the same sensitivity of network, but with a less number of stations, the new network would enable to determine hypocenter parameters in a more precise at a more uniform distribution of errating band within observation area.  相似文献   

Effects of spilled oil on microbial communities in a tidal flat     

Katayama Y  Oura T  Iizuka M  Orita I  Cho KJ  Chung IY  Okada M 《Marine pollution bulletin》2003,47(1-6):85-90

Effects of spilled oil on microbial communities in tidal flats were examined by use of a simulator for a tidal flat ecosystem. The simulator is composed of a wave generator, a tide control device, and a tidal flat. Sediment for the tidal flat was obtained at a natural tidal flat in Hiroshima Bay, Japan. After stabilizing the benthic organisms, fuel oil C was added to the surface of the flat at 1 lm(-2). Although the total number of micro-organisms remained at 1.5-3.5 x 10(9) cells g(-1) dry sediment irrespective of the addition of oil, bacterial communities which were analyzed based on the 16S rDNA showed clear changes after the addition of fuel oil C and after a subsequent recovery period. Bacterial colonies were randomly isolated from the oil-supplemented sediment during the experiments, and the isolates were examined for susceptibility to hydrocarbons in order to screen the oil-susceptible bacteria. The proportion of oil-susceptible bacteria in the isolates decreased with the addition of the oil. Oil-susceptible bacteria showed an inability to assimilate petroleum compounds as well as an inhibition of growth. The possibility of using oil-susceptible bacteria as an indicator of bioremediation in tidal flats was discussed.  相似文献   

210Pb-derived sediment accumulation rates in the southwestern East Sea (Sea of Japan)     

G. H. Hong  S. H. Kim  C. S. Chung  D.-J. Kang  D.-H. Shin  H. J. Lee  S.-J. Han 《Geo-Marine Letters》1997,17(2):126-132

 Recent sediment accumulation rates are 18–230 mg cm^-2 yr^-1 (0.02–0.2 cm yr^-1) based on excess ²¹⁰Pb activity profiles in the southwestern part of the East Sea (Sea of Japan). Assuming no mixing beneath surface mixed layers, ²¹⁰Pb-derived sediment accumulation rates are 18–32 mg cm^-2 yr^-1 in the northern part of the Yamato Ridge and the Ulleung Basin, 29–136 mg cm^-2 yr^-1 in the Korea Plateau, and 230 mg cm^-2 yr^-1 in the southern shelf. These values generally agree with long-term sedimentation rates estimated from dated ash layers. Received: 6 October 1995 / Revision received: 31 May 1996  相似文献   

Early Cretaceous gabbroic complex from Yinan,Shandong Province: petrogenesis and mantle domains beneath the North China Craton   总被引：12，自引：1，他引：11  

Yi-Gang?XuEmail author  Jin-Long?Ma  Xiao-Long?Huang  Yoshiyuki?Iizuka  Sun-Lin?Chung  Yan-Bin?Wang  Xiang-Yang?Wu 《International Journal of Earth Sciences》2004,93(6):1025-1041

Sensitive high resolution ion microprobe (SHRIMP) zircon U–Pb ages, geochemical and Sr-Nd-Pb isotopic data are reported for the gabbroic complex from Yinan (Shandong Province) with the aims of characterizing the nature of the Mesozoic mantle beneath the North China Craton. The Yinan gabbros contain alkali feldspar and biotite, and are characterized by moderate Mg#, high SiO₂, low FeO and TiO₂ contents and a strong enrichment of light rare earth elements [(La/Yb)_n=11–50], but no Eu anomaly. They have low Nb/La (0.07–0.29), radiogenic ⁸⁷Sr/⁸⁶Sr (0.710) and unradiogenic _Nd(t) (–15 to –13). These crustal fingerprints cannot be attributed to crustal contamination, given the lack of correlation between isotopic ratios and differentiation indices and the unreasonably high proportion of crustal contaminant (>20%) required in modeling. Instead, compositional similarities to contemporaneous basalts from nearby regions imply that the Yinan gabbros were not significantly affected by crystal cumulation. Isotopic data available for the Mesozoic mafic magmas reveal two distinct mantle domains beneath Shandong. While the EM1-like domain (with low ⁸⁷Sr/⁸⁶Sr) is confined to western Shandong, the mantle beneath eastern Shandong is dominated by EM2-type (with high ⁸⁷Sr/⁸⁶Sr) affinities. This aerial distinction suggests that the EM2-like signature of the Yinan gabbros may have been inherited from westerly-subducted Yangtze crust during the Triassic North China-South China collision. Emplacement of the Yinan gabbros (127 Ma) is likely affiliated with the widespread and protracted extension during the late Mesozoic in this region.  相似文献   

Photochemical processes on Titan: Irradiation of mixtures of gases that simulate Titan's atmosphere     

Buu N. Tran  Michael Force  Veronique Vuitton 《Icarus》2005,177(1):106-115

Photochemical reaction pathways in Titan's atmosphere were investigated by irradiation of the individual components and the mixture containing nitrogen, methane, hydrogen, acetylene, ethylene, and cyanoacetylene. The quantum yields for the loss of the reactants and the formation of products were determined. Photolysis of ethylene yields mainly saturated compounds (ethane, propane, and butane) while photolysis of acetylene yields the same saturated compounds as well as ethylene and diacetylene. Irradiation of cyanoacetylene yields mainly hydrogen cyanide and small amounts of acetonitrile. When an amount of methane corresponding to its mixing ratio on Titan was added to these mixtures the quantum yields for the loss of reactants decreased and the quantum yields for hydrocarbon formation increased indicative of a hydrogen atom abstraction from methane by the photochemically generated radicals. GC/MS analysis of the products formed by irradiation of mixtures of all these gases generated over 120 compounds which were mainly aliphatic hydrocarbons containing double and triple bonds along with much smaller amounts of aromatic compounds like benzene, toluene and phenylacetylene. The reaction pathways were investigated by the use of ¹³C acetylene in these gas mixtures. No polycyclic aromatic compounds were detected. Vapor pressures of these compounds under conditions present in Titan's atmosphere were calculated. The low molecular weight compounds likely to be present in the atmosphere and aerosols of Titan as a result of photochemical processes are proposed.  相似文献