Thư viện tài liệu, ebook tham khảo dành cho học sinh, sinh viên
Thư viện tài liệu trực tuyến miễn phí dành cho các bạn học sinh, sinh viên
Influence of operating conditions and membrane fouling on water flux during seawater desalination using air gap membrane distillation - Duong Cong HungResults from this study demonstrate the great viability of seawater AGMD desalination for fresh water provision in remote coastal areas in Vietnam. During the AGMD process of seawater, the operating conditions, particularly feed temperature and circulation rate, strongly affected the process water flux. Operating the process at high feed tem...
7 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 858 | Lượt tải: 0
Study on the effect of carbon black, carbon nanotube on the properties of rubber blend acrylonitrile butadiene rubber (NBR)/polyvinyl chloride (PVC) - Luong Nhu HaiThe thermal stability of the material is evaluated by Thermogravimetric Analysis (TGA). The results of TGA analysis of material samples based on NBR/PVC blend are shown in figures 6-8 and table 3. When replacing 1 phr CB by CNT, thermal stability of the rubber blend continues to rise (onset decomposition temperature increased by nearly 10°C)...
6 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 804 | Lượt tải: 0
Si11Mn0/+ cluster is endohedral or exohedral: a proof by DFT calculation - Cao Thi Thanh HuongThe B3P86/6-311+G(d) quantum chemical calculation method has been employed for searching the stable geometrical structures of Si11, Si11Mn+, and Si11Mn0 clusters. While for the lowest energy structure of Si11Mn+ cationic cluster, the Mn dopant locates outer the Si11 cage forming the exohedral isomer, the endohedral isomers which have relative...
7 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 819 | Lượt tải: 0
Sterols from stems of Momordica cochinchinesis (Lour.) Spreng - Nguyen Thi MaiThe molecular formula of 3 was suggested as C29H48O (M = 412) by the ESI-MS ion peak at m/z 411 [M-H]- and NMR data. The 1H-NMR spectrum of 3 showed signals for 6 methyl groups at δH 0.55 (3H, s), 0.79 (3H, d, J = 6.5 Hz), 0.80 (3H, s), 0.81 (3H, t, J = 7.5 Hz), 0.85 (3H, d, J = 6.5 Hz) and 1.03 (3H, d, J = 6.5 Hz). Besides, the presence of ...
5 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 770 | Lượt tải: 0
One-Pot, selective synthesis of orthorhombic and rhombohedral NaNbO3 by hydrothermal method - Nguyen Duc VanBy simply tuning the (K++Na+)/Nb5+ molar ratio from 9.0 to 12.0, the pure rhombohedral and orthorhombic NaNbO3 microcrystals were selectively synthesized by an additive-free hydrothermal procedure using commercialized Nb2O5, NaOH, KOH as starting materials at 180 and 200 oC, respectively, for 24 h. The results showed that the phase compositi...
4 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 767 | Lượt tải: 0
Experimental method to determine the pore structure and pore size distribution of gamma alumina (-Al2O3) material - Vu Hong ThaiTo conclude, in this work, the experiments to determine the pore size structure and the pore size distribution of γ-Al2O3 particles are presented. By using the environmental scanning electron microscopy (ESEM), it is observed that the samples have a bimodal pore size distribution with large pores (approximately 1.5 m) and small pores (appro...
8 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 901 | Lượt tải: 0
Isolation and identification of phenolic compounds from the leaf extract of Cassia alata L - Pham Quang DuongIn our study, the MeOH leaf extract of C. alata exhibited a significant antibacterial activity against human pathogenic bacteria strains S. aureus and B. cereus with the same MIC value of 63 µg/ml (data not shown). The phytochemical constituents in the leaves of C. alata were also determined to be as methyl 2,4,6-trihydroxybenzoat (1), kaempf...
6 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 776 | Lượt tải: 0
Electrochemical deposition of NiCu alloys in citrate solutions - Uong Van VyObserve polarization curves can see Ni2+ ions starting discharge at electrode potential from -0.8 V/SCE, the electrode potential more negative then cathode current density higher. The slope of the polarization curve increases with increasing of Ni2+ ion concentration, polarization curves in solution Ni2+ 0.3 M began appearing critical current...
4 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 1081 | Lượt tải: 0
A thoroughly theoretical investigation into complexes formed by interaction of dimethyl sulfoxide with two water molecules - Pham Ngoc KhanhInteraction of dimethyl sulfoxide with two water molecules induces three quite stable complexes with interaction energies between -30.3 and -52.7 kJ.mol- 1 at MP2/6-311++G(2d,2p) level. The stability of obtained complexes is mainly determined by the O−H∙∙∙O hydrogen bonds along with the complementary role of O−H∙∙∙S and C−H∙∙∙O hydrogen bond...
7 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 845 | Lượt tải: 0
Some triterpenoids and steroids from Bruguiera cylindrica leaves collected from Can Gio mangrove forest - Nguyen Thi Huong QueCompound 4 was isolated as a white amorphous powder. Based on the HR-ESI-MS spectrum, the molecular formula of 4 was determined as C27H44O with a pseudomolecular ion peak at m/z 385.3448 [M+H]+ (calc. for C27H44O+H, 385.3470). The 1H-NMR spectrum of 4 displayed a singlet at δ 5.72 (1H, s, H-4), three methyl doublets at δ 0.91 (3H, d, J = 6.5...
4 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 828 | Lượt tải: 0
