General characteristics of rare earth and radioactive elements in Dong Pao deposit, Lai Chau, VietnamThe Dong Pao deposit is rich in light rare earth elements such as La, Ce, Pr and Nd, their total concentration approximates 10 wt.% in the weathered zone. The mass contents of uranium and thorium in the studied REE deposit are comparable reaching about 0.01 wt.% and 0.001 wt.% in the upper weathered and lower limestone and dolomite zones re...
13 trang | Chia sẻ: honghp95 | Ngày: 30/11/2020 | Lượt xem: 946 | Lượt tải: 0
Eruptive-Volcanic-basalt structures in the Truong SaSpratly Islands and adjacent areas from interpreting gravity and magnetic dataThe method of multi-dimensional correlation analysis between the high-frequency gravity, magnetic anomalies with weighted total gradient 3D allows determining quite accurately the ranges as well as the spatial locations of the eruptive volcanic basalts in the Spratly Islands and adjacent areas. The diversity of the formation and the complex ph...
13 trang | Chia sẻ: honghp95 | Ngày: 30/11/2020 | Lượt xem: 674 | Lượt tải: 0
Utilization of seismic refraction data for the study of structure of Bang hot-Water source, Le Thuy, Quang BinhA good quality seismic data was recorded by all the deployed instruments in the area of the hot water spring Bang - Quang Binh. The limitation in length of the measurement profiles caused by the complexity of the local condition is restricted the investigation depth in a range of 2 - 3 km. The velocity structural models under 4 profiles con...
16 trang | Chia sẻ: honghp95 | Ngày: 30/11/2020 | Lượt xem: 654 | Lượt tải: 0
Petrography and geochemistry of Permian basalts of the Cam Thuy formation and their relation to Song Da and Emeishan magmatic rocksCam Thuy Permian volcanic rocks exposed in the Lam Son area (Tho Xuan, Thanh Hoa province) comprise thick basaltic lava flows and pyroclastic layers, with a total thickness exceeding a few hundred meters. The rock types are mostly olivine-phyric basalt and a minor amount of alkaline basalt and (quartz-normative) tholeiitic basalt. The compu...
21 trang | Chia sẻ: honghp95 | Ngày: 30/11/2020 | Lượt xem: 746 | Lượt tải: 0
Characteristics of elemental and organic carbon in atmospheric nanoparticles at different sampling locations in VietnamThe atmospheric carbonaceous components, particularly OC, EC, char – EC and soot – EC in the NPs, were measured in a rainy season and a dry season (August to December) at the two locations in Hanoi, Vietnam. It was found that OC accounts for 78.6 – 81.5 of TC in the NPs at the Vinacomin site, and 83.7 – 85.0 % of TC in the NPs at HUST site. The ...
11 trang | Chia sẻ: honghp95 | Ngày: 30/11/2020 | Lượt xem: 693 | Lượt tải: 0
Effect of silicic acid on aggregation of hydrous ferric oxideIn natural waters, silicic acid occurs almost exclusively in the form of the monomer (Si(OH)4) or dimer (Si2O2(OH)5-) (Svensson et al., 1986; Dietzel, 2000). Variation in protonation/deprotonation and/or polymeric condensation can potentially yield other dissolved species (e.g. oligomeric silicic acids) (Iler, 1979; Dove and Rimstidt, 1994; ...
11 trang | Chia sẻ: honghp95 | Ngày: 30/11/2020 | Lượt xem: 734 | Lượt tải: 0
Prediction of maximum earthquake magnitude for northern Vietnam region based on the gev distributionOn the basis of the catalog of independent earthquakes in period 1972-2014, the maximum earthquake magnitude value was assessed for the Northern Vietnam using GEV method. We obtained the following sample estimates for this catalog with T = 350 days: = - 0.178 ± 0.08 ; = 0.23 ± 0.08; = 4.39 ± 0.16; This distribution can be characteriz...
6 trang | Chia sẻ: honghp95 | Ngày: 30/11/2020 | Lượt xem: 816 | Lượt tải: 0
Study of the morphology of the low-Latitude D region ionosphere using the method of tweeks observed at Buon Ma Thuot, Dak LakObserving 23073 tweeks with the first to eighth harmonics using the UltraMSK receiver installed at Tay Nguyen University (12.65°N, 108.02°E) during January - June 2013, we have studied the morphology of the nighttime D region ionosphere. We can conclude as follows, - The second to third harmonic tweeks occurred often. The tweeks with the hi...
12 trang | Chia sẻ: honghp95 | Ngày: 30/11/2020 | Lượt xem: 676 | Lượt tải: 0
Effect of the change of climate indicators on agricultural yields in Son La provinceDue to the impact of climate change, the climate indicators in Son La province change according to the following trends: (i) the total annual heat increases; (ii) the period of winter tends to shorten; (iii) the absolute lowest annual temperature tends to rise; (iv) the amount of evaporation tends to increase. Therefore, production period of som...
11 trang | Chia sẻ: honghp95 | Ngày: 30/11/2020 | Lượt xem: 797 | Lượt tải: 0
TEC variations and ionospheric disturbances during the magnetic storm in March 2015 observed from continuous GPS data in the Southeast Asia regionBased on the observations and calculations, we can draw some conclusions: The results of TEC calculation by using the combination of the phase and pseudo range measurements are less dispersed than those by using only the pseudo range measurements. The magnetic storm whose the main phase stated on 17 March 2015 was the big storm. The minimu...
19 trang | Chia sẻ: honghp95 | Ngày: 30/11/2020 | Lượt xem: 787 | Lượt tải: 0
