Tổng hợp tài liệu Khoa Học Tự Nhiên tham khảo cho học sinh, sinh viên.
The undoped and Cu doped ZnS microstructures on Si/SiO2 substrates have been successfully synthesized by a thermal evaporation method. The undoped ZnS microbelts shows a broad band emission at visible region at around 520 nm which related to radiative centers of ZnS and ZnO. By doping Cu with various concentration, the emission band of radiative...
7 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 516 | Lượt tải: 0
Study on the correlation between nitrogen content in soil and nitrate accumulation in farming producs have important implications to determine the amount of nitrogenous fertilizer required and appropriate time for harvest, to minimize the effects on human health caused by NO3- residues in agricultural products. This study was conducted on eight c...
6 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 546 | Lượt tải: 0
In this paper, the morphology, microstructure, thickness, weight and composition of the trivalent chrome conversion coating (CCCs) on zinc electroplating with different dipping times (10, 20, 40, 50, 60, 70 and 80 s) have been studied. The thickness, weight of the layer increases with dipping time in the bath. Thickness, weight of the CCCs as a ...
10 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 575 | Lượt tải: 0
In order to sustainable use resource of lithium ore in La Vi area, Quang Ngai province, this research was performed using ICP-MS, AAS, thin section with light microscopy, and XRD with BGMN based on Rietveld method to carry out main characteristics of the pegmatite. Observed minerals include quartz (32%), plagioclase (51%), muscovite (10%), lepido...
8 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 668 | Lượt tải: 0
Qua những nghiên cứu trên tại khu vực bãi giếng, đã sáng tỏ đặc điểm phân bố của mangan trong nước dưới đất của tất cả các tầng chứa nước. Hàm lượng Mn2+ trong nước dưới đất biến đổi theo mùa, sự dao động hàm lượng theo mùa tuy không lớn song biểu hiện khá rõ. Hàm lượng Mn2+ cùng với hàm lượng sắt tổng tăng dần theo chiều sâu tới tầng chứa n...
7 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 592 | Lượt tải: 0
In this study, the effects of lime addition on the sludge digestion by sodium hydroxide were investigated. The optimum dosage and time required for sludge digestion using only NaOH were found to be 1.6 g/L and 3 hours, respectively. At the optimised condition, lime was added at varying concentration (0.3 g/L to 1.6 g/L). As a result, soluble COD...
6 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 555 | Lượt tải: 0
The MEMS based devices market is growing rapidly and widely exploited for reliable, low cost applications used in the field of bio-chemical sensors. In this work the piezoresistive micropressure sensors were used as the sensing platform with analyte specific stimuli response hydrogels as the sensory material for chemical sensing. The tests have b...
8 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 540 | Lượt tải: 0
GPS outage is a serious problem for any INS/GPS integration system. This paper has succeeded in embedding the street return algorithm into a conventional low-cost INS/GPS integration system [16] in order to reduce the vehicle’s drift when it falls off the street due to GPS outage. The simulated results show that the proposed system offers a devi...
10 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 481 | Lượt tải: 0
Vietnam has a rather well developed fishery industry, the materials used for fish oil production are abundant, what is the condition for efficient development of fish oil production industry. To ensure the quality of fish oil, the matter of protecting product from oxidation is very important. Using antioxidants is an effective way, however the u...
9 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 581 | Lượt tải: 0
Based on available materials and data obtained from the report of the national project KC.09.08.11/15, we recorded a total of 58 species of coral reef fishes belonging to 34 genera in 15 families from the marine waters of Bach Long Vi island, Hai Phong city. The fish fauna represents the sub-tropical characteristics by the absence of several key...
7 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 544 | Lượt tải: 0
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