After investigate students in middle schools and universities,the authors discover that the students have difficulties in understanding rectilineal propagation of light.

Effects of mulching on emergence rate of direct seeding of four tree species

This paper expounds afforesting technique of direct seeding oriental arborvitae from place choice, seeding season, afforesting method, seedling management etc and discusses technical points from experience.

Although in the early phases of establishment direct seeded sites can appear abandoned and unmanaged compared to neatly planted, well-maintained rows of trees, direct seeding has a number of potential advantages over conventional planting of intact root system, a good suitability of planting site, simple construction and being cheaper (Willough et al.

59% of Castanopsis fargesii;The water content of Fagaceae seed is relatively high,the seed sprouts is not needed moisture basically;Prevent rodent dig food to direct seeding afforestation the key to succeed in,prevention method:The application of the behavior and the in.

The results show: 1)Direct seeding afforestation in autumn, it will more effective if seeding in shady hillside than that in sunny and semishady hillside; Govering soil of 4 centimeter is more effective than 2 centimeter and 6 centimeter.

Preliminary observation on efficacy and safety of telbivudine for preventing mother-to-infant HBV vertical transmission in five HBV-infected pregnant women;

Epidemiologic study on vertical transmission of Candida from mother to their neonate;

Clinical study of preventing HBV vertical transmission by lamivudine treatment combined with active-passive immunization for pregnant women;