[Macrobenthos community structure of macrobenthos and bioassessment of water quality in main stream of Songhua River].

An investigation was conducted on the community structure of macrozoobenthos in the main stream of Songhua River in spring (April and May), summer (July and August), and autumn (from September to November), and the water quality of the main stream was assessed with biotic indices. A total of 116 species of macrobenthos were collected, belonging to 36 families and 16 orders, among which, aquatic insects had the largest number, with 74 species (63.8% of the total) belonging to 21 families and 6 orders.

[Methane emission flux of Zhalong Phragmites australis wetlands in growth season].

Static chamber/gas chromatogram method was adopted to measure the methane emission flux of Zhalong Phragmites australis wetlands with different water levels in a growth season from May to October, 2009, aimed to understand the methane emission pattern in natural freshwater P. australis wetland in frigid region. During the observation period, the average methane emission flux of test wetlands ranged from -21.

The cranial cervical ganglion and its branches in the yak (Bos grunniens).

The heads and necks of 10 yaks were dissected to study the shape, location, arrangement, and branches of the cranial cervical ganglion. The ganglion was a greyish fusiform structure, mean length 19.72 mm, width 7.