Content Variations of the Secondary Compounds in Rice Plants and Their Influence on Rice Resistance to Brown Planthopper,Nilaparvata lugens

Content variations of the four components in the plants of rice ASD7, IR36 （resistant to brown planthopper） and TN1 （susceptible to brown planthopper）, and their influence on rice resistance to brown planthopper （BPH, Nilaparvata lugens） were investigated. The resistance diversity of rice to BPH biotype II at different plant ages was chiefly attributed to the content variability of the secondary compounds. The contents in the leaf sheath were the lowest as compared with other parts of rice plant. It might explain the reason that BPH has a preference for feeding on leaf sheath aggregately from chemical point of view.

Seasonal variation and modal content of internal tides in the northern South China Sea

A nine-month mooring record was used to investigate seasonal variation and modal content of internal tides(ITs) on the continental slope in the northern South China Sea(SCS). Diurnal tides at this site show clear seasonal change with higher energy in winter than in spring and autumn, whereas semidiurnal tides show the opposite seasonal pattern. The consistency of ITs with barotropic tides within the Luzon Strait, which is the generation region of the ITs, implies that the seasonal variation of ITs depends on their astronomical forcing, even after extended propagation across the SCS basin. Diurnal tides also differ from semidiurnal tides in relation to modal content; they display signals of high modes while semidiurnal tides are dominated by low modes. Reflection of the diurnal tides on the continental slope serves as a reasonable explanation for their high modes. Both diurnal and semidiurnal tides are composed of a larger proportion of coherent components that have a regular 14-day spring-neap cycle. The coherent components are dominated by low modes and they show obvious seasonal variation, while the incoherent components are composed mainly of higher modes and they display intermittent characteristics.

Investigating spatial and temporal variations of soil moisture content in an arid mining area using an improved thermal inertia model

Mining operations can usually lead to environmental deteriorations. Underground mining activities could cause an extensive decrease in groundwater level and thus a dramatic variation in soil moisture content（SMC）. In this study, the spatial and temporal variations of SMC from 2001 to 2015 at two spatial scales（i.e., the Shendong coal mining area and the Daliuta Coal Mine） were analyzed using an improved thermal inertia model with a long-term series of Landsat TM/OLI（TM=Thematic Mapper and OLI=Operational Land Imager） data. Our results show that at large spatial scale（the Shendong coal mining area）, underground mining activities had insignificant negative impacts on SMC and that at small spatial scale（the Daliuta Coal Mine）, underground mining activities had significant negative impacts on SMC. Trend analysis of SMC demonstrated that areas with decreasing trend of SMC were mainly distributed in the mined area, indicating that underground mining is a primary cause for the drying trend in the mining region in this arid environment.

Feeding habit and seasonal variation of stomach contents of sand dabs, Pseudopleuronectes yokohamae, in the South Bohai Sea

Sand dabs, an important commercial flatfish in the Bohai Sea, has recently decreased gradually in biomass, resulting from overfishing and marine pollution. Artificial culture and multiplication of sand dabs are essential and practical in China. The present paper examines the food habitof this fish to provide detailed information for its culture and multiplication.

Multiscale analysis of the contents of palmatine in the Nature populations of Phellodendron amurense in Northeast China

Palmatine is a valuable ingredient in Chinese medicine that is produced by Phellodendron amurense Rupr. The contents of palmatine content in root bark, trunk bark, perennial branch bark, annual branches, and leaves of the trees with different ages and geographies in Northeast China were measured by high-performance liquid chromatography. The contents of palmatine in the barks of root, trunk, and perennial branch were significantly higher than those in annual branches and leaves. The contents of palmatine in trunk bark and root bark from Lesser Khingan Mountains increased with age, which is significantly opposite to other three vegetation types. The contents of palmatine in perennial branch bark, annual bark and leaves had no significant reg- ularity. Moreover, the contents of palmatine in samples of root bark, trunk bark, perennial branch bark and annual bark varied significantly with latitude. The nature populations of P. amurense growing at low latitude contained significantly more palmatine than those growing at high latitude. These results provide a scientific basis for the reasonable cultivation and efficient utilization of P. amurense.

SEASONAL VARIATION OF LIDAR-DERIVED AEROSOL CONTENT IN THE LOWER LAYERS OF THE ATMOSPHERE

Results of the study of seasonal variation of total column content of aerosols in the 50—1100 m height region are presented,The columnar content of aerosols is computed by integrating the height profiles of nighttime aerosol number density estimated from the Argon ion lidar observations collected at the ⅡTM, Pune for the one year period from October 1986 to September 1987.The results of the study indicated that the aerosol content was higher during winter than during monsoon months by over 78% with an annual mean columnar aerosol content of 1.66×10~8 cm^(-2).The observed seasonal variaticn of aerosol content was found to be associated with that of surface wind,temperature,relative humidity(R.H.)and rainfall data recorded for the above one year period at the station.