http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
온대 숲 토양 생태계에서 지렁이가 톡토기류 개체수에 미치는 영향
이주형 ( Ju Hyung Lee ),박지현 ( Ji Hyun Park ),유지연 ( Ji Yeon Yoo ),한수현 ( Su Hyun Han ),남보은 ( Bo Eun Nam ),김재근 ( Jae Geun Kim ) 한국환경복원기술학회(구 한국환경복원녹화기술학회) 2010 한국환경복원기술학회지 Vol.13 No.6
Earthworm, a prominent ecosystem engineer within many terrestrial ecosystems, can exert profound influences on various abiotic/biotic environments through bioturbation processes such as burrowing, casting and mixing of litter and soil. In this study, we investigated how the presence or absence of earthworm (Oligochaeta) can alter the soil physico-chemical conditions and ultimately the distribution and abundance of Collembola which constitutes a large proportion of the soil fauna. During September 2010, soil organisms along with soil samples were collected from randomly installed 20 plots in Mt. Gwan-ak. We examined the differences in the abundance of Collembola among plot samples in respect to the presence/absence of earthworm and soil physico-chemical conditions (i.e., pH, PO43-, NO32-, organic matter (OM), electrical conductance and water content). Analysis of soil physico-chemical environment revealed a significantly higher organic matter content and electrical conductance in plots with earthworm compared to plots without earthworm. Abundance of Collembola were not only higher in plots with earthworm than in plots without earthworm, but were also positively correlated with availability of OM present in the environment. The results suggest that positive impacts of earthworm on the abundance of Collembola in this study may have been due to their ability to effectively modify soil physico-chemical conditions favored by Collembola. Such conspicuous influence of earthworm`s activity on below-ground community suggests their potential significance in forest restoration or revegetation process.
이홍서,김종철,한수현 충주대 산업과학기술연구소 1995 産業科學論文集 Vol.3 No.-
Mechnical properties and rotary bending fatigue tests of ductile cast irons were carried out. According to the results of experiment, when the ductile cast irons shows lower strength furnace cooling (annealing heat treatment), it shows higher air cooling (normalizing heat treatment). This implies that the nodule distribution is affected by changes taking place during the austenite to ferrite+graphite transformation. On the other hand, fatigue crack depends upon the magnitude of stress, but in the initiation propagated after holding in time, the crack growth propagates rapidly with an increased number of cycles. Fatigue life of ductile cast iron depends very strongly on the pearlite content and the distribution of pearlite in the microstructure. Observation of the fatigue surface of microstructure on the as-cast let to the finding that microcrack was produced by the plastic transformation and ductile fracture occured.