Thư viện tài liệu, ebook tổng hợp lớn nhất Việt Nam

SUMMARY Phong Nha-Ke Bang National Park (PNKB NP), located in Quang Binh Province, with total area of 85,755 ha, has high national and global biodiversity conservation significance. However, rodent fauna in the National Park is poorly studied. Preliminary surveys conducted before 2002 has recorded only 29 species.Nguyen Xuan Nghia, Nguyen Xuan D...

8 trang | Chia sẻ: thucuc2301 | Ngày: 30/11/2020 | Lượt xem: 849 | Lượt tải: 0

Sandoricum koetjape (Meliaceae) has been used in traditional medicine for the treatment of diarrhea, dysentery, and as a tonic for women after giving birth. We have studied the chemical constituents of an ethyl acetate extract of the bark of the species collected in Binh Duong Province and isolated five compounds, bryononic acid, 3-oxo-olean-12-...

7 trang | Chia sẻ: yendt2356 | Ngày: 30/11/2020 | Lượt xem: 912 | Lượt tải: 0

Compound (4) was isolated as yellow needle. The 13C-NMR spectrum (Table 4) showed 27 signals including nine olefinic quatenary carbons at δ 166.0, 163.0, 159.3, 158.5, 149.8, 145.8, 135.6, 123.1, 105.6, five aromatic methine carbon signals at δ 125.6, 117.7, 116.1, 100.0, 94.9, two anomeric carbon signals at δ 104.7 and 102.4, nine oxygenate...

8 trang | Chia sẻ: yendt2356 | Ngày: 30/11/2020 | Lượt xem: 674 | Lượt tải: 0

SUMMARY This paper provided a review of leaf-nosed bats (Hipposideridae) from Vietnam and important characteristics of a Vietnamese endemic bat species. In previous publications including bats of Vietnam, records of four species (Hipposideros bicolor, H. fulvus, H. turpis, Paracoelops megalotis) resulted from improper identification. Without do...

7 trang | Chia sẻ: thucuc2301 | Ngày: 30/11/2020 | Lượt xem: 880 | Lượt tải: 0

Distribution: Northern, Central part and Tay Nguyen Plateau Vietnam, Son La, Ha Giang, Tuyen Quang, Lang Son, Hoa Binh, Thai Nguyen, Vinh Phuc, Bac Giang, Hai Duong, Quang Ninh, Thanh Hoa, Nghe An, Quang Binh, Quang Tri, Gia Lai and Lam Dong; India, Cambodia, Laos and China. Ecology and habitat: Primary broad-leaved evergreen closed forest,...

7 trang | Chia sẻ: yendt2356 | Ngày: 30/11/2020 | Lượt xem: 730 | Lượt tải: 0

KẾT LUẬN Vòng đời của A. longispinosus tại 25, 30 và 35°C lần lượt là 5,69; 5,02 và 3,77 ngày đối với con cái và 5,93; 4,94 và 3,37 ngày đối với con đực. Không có sự khác biệt về thời gian để hoàn thành vòng đời giữa con đực và con cái tại các điều kiện nhiệt độ khác nhau nhưng nhiệt độ càng cao thì thời gian để hoàn thành vòng đời của cả c...

9 trang | Chia sẻ: thucuc2301 | Ngày: 30/11/2020 | Lượt xem: 820 | Lượt tải: 0

From the methanol extract of the root of Streptocaulon juventas Merr, three cardenolide derivatives were isolated. Their strutures were determined by spectroscopic methods. This is the first time that (17α)-H-periplogenin-3-O-β-D-glucopyranosyl-(1–4)-2-O-acetyl-3-O-methyl-β- fucopyranoside (1) and periplogenin-3-O-β-cymaropyranosyl-(1→4)--gluco...

8 trang | Chia sẻ: yendt2356 | Ngày: 30/11/2020 | Lượt xem: 786 | Lượt tải: 0

SUMMARY Ground beetle Chlaenius inops Chaudoir is an important predator in limiting bollwowm Helicoverpa armigera (Hubner) population on rice, groundnut, maize in Nghe An privince. The beetle Ch. inops has the four following development stages: eggs are white; larvae black, head yellowish brown; pupation in the soil or on the ground. Five and s...

6 trang | Chia sẻ: thucuc2301 | Ngày: 30/11/2020 | Lượt xem: 885 | Lượt tải: 0

From flower of Wedelia trilobata Hitch. five triterpenoids: friedelan-3β-ol (or epifriedelanol) (1), erythrodiol (2), 28- hydroxy-3β-tetradecanoyloxyolean-12-ene (or 3β-tetradecanoyloxyerythrodiol) (3), 3β- henicosanoyloxyolean-12-en-28-oic acid (4), 3β-pentadecanoyloxyolean-28(13)-lactone (5), one diterpenoid: kaura-9(11),16-dien-18-oic ac...

8 trang | Chia sẻ: yendt2356 | Ngày: 30/11/2020 | Lượt xem: 739 | Lượt tải: 0

SUMMARY The survey on fishes in Boi river basin was conducted from 2011 to 2012. There were 83 fish species indentified, there were 30 species unrecorded from 113 fish species reported by the previous authors. The total number of fish species revealed in the Boi basin river belongs to 77 genera, 30 families and 10 orders. Of the total families,...

10 trang | Chia sẻ: thucuc2301 | Ngày: 30/11/2020 | Lượt xem: 880 | Lượt tải: 0