Reference the seabed topographic depth observations based on the national mean dynamic topography model.

The mean sea surface in different regions is non-equipotential, rendering Vietnam's traditional approach, which relies on the Hon-Dau tide gauge station as a reference, not yet scientifically invalid. To overcome this, our study utilized the Vietnam national mean dynamic topography model (MDTVN22) for depth observations, particularly in the Gulf of Tonkin. Covering 3430 monitoring sites in Hai Phong and 813 sites in Quang Ninh, our experiments highlighted a 5 to 6 mm difference between the mean sea surface and MDTVN22 references.

(Apocynaceae, Asclepiadoideae), a new species from Vietnam.

(Apocynaceae, Asclepiadoideae), a new species from Vietnam is described, illustrated and compared with the similar species Kerr. differs from by the morphology of the rachis of the inflorescence, the margins of the corolla lobes and the colour of the adaxial surface of the corolla.

Sex attractants for moths of Vietnam: field attraction by synthetic lures baited with known lepidopteran pheromones.

Screening tests of synthetic lepidopteran sex pheromones were carried out at orchards in the Mekong Delta over an approximately two-year period starting from December 1998. Monoenyl acetates with a C10-C14 chain attracted six species distributed mainly in Southeast Asia: Adoxophyes privatana, Archips atrolucens, and Meridemisfurtiva in the Tortricidae family, and Argyrogramma signata. Spodoptera pectinicornis, and Zonoplusia ochreata in the Noctuidae family.