The distribution characteristics of methyl mercury in Rana chensinensis and water,sediment and soil in gold-mining areas of the upper reaches of the Songhua River,China were studied by field sampling and laboratory te...The distribution characteristics of methyl mercury in Rana chensinensis and water,sediment and soil in gold-mining areas of the upper reaches of the Songhua River,China were studied by field sampling and laboratory testing.The results show that the methyl mercury contents in water,sediment and soil in gold-mining areas are much higher than those in the control site,indicating that gold-mining activities intensify the methyl mercury pollution in the study area.Methyl mercury contents are in a descending order of sediment > soil > water in the environment,and in a descending order of brain > viscera > muscle > skin in Rana chensinensis.There are significant correlation between methyl mercury contents in Rana chensinensis and those in water and sediment.In particular,the methyl mercury content in the skin of Rana chensinensis is positively correlated with those in water and sediment in spring.Therefore,skin is one of main intake pathways for methyl mercury due to its high permeability.展开更多
With the development of network economy, e-commerce platform has increasingly become a worldwide trading places of various kinds of products and services. Therefore some scholars consider, intermediaries, under the ra...With the development of network economy, e-commerce platform has increasingly become a worldwide trading places of various kinds of products and services. Therefore some scholars consider, intermediaries, under the rapid development of information technology, will gradually withdrew from the historical stage. This article carried on the thorough analysis for the reasons of the existence of electronic intermediaries, and discusses the new development space and prospect of new middlemen, from the perspective of information asymmetry of the network environment.展开更多
One of the challenges in foreign language teaching, specifically teaching listening skill, is to create a low-anxiety classroom environment, since many learners believe listening induces anxiety. This study compares l...One of the challenges in foreign language teaching, specifically teaching listening skill, is to create a low-anxiety classroom environment, since many learners believe listening induces anxiety. This study compares learners＇ anxiety in two different classrooms in which learners were instructed by two forms of artifacts： materializing and verbalizing. The Foreign Language Listening Anxiety Scale （FLLAS） scores before and after a 13-week experimental treatment course were used to compare learners＇ anxiety before and after receiving intervention by two means. In this study, the lower score of anxiety was for the group which did verbalization practice in the class; however, both groups showed the same performance on listening test.展开更多
基金Under the auspices of National Natural Science Foundation of China (No. 40673059)Testing Foundation of Northeast Normal University
文摘The distribution characteristics of methyl mercury in Rana chensinensis and water,sediment and soil in gold-mining areas of the upper reaches of the Songhua River,China were studied by field sampling and laboratory testing.The results show that the methyl mercury contents in water,sediment and soil in gold-mining areas are much higher than those in the control site,indicating that gold-mining activities intensify the methyl mercury pollution in the study area.Methyl mercury contents are in a descending order of sediment > soil > water in the environment,and in a descending order of brain > viscera > muscle > skin in Rana chensinensis.There are significant correlation between methyl mercury contents in Rana chensinensis and those in water and sediment.In particular,the methyl mercury content in the skin of Rana chensinensis is positively correlated with those in water and sediment in spring.Therefore,skin is one of main intake pathways for methyl mercury due to its high permeability.
文摘With the development of network economy, e-commerce platform has increasingly become a worldwide trading places of various kinds of products and services. Therefore some scholars consider, intermediaries, under the rapid development of information technology, will gradually withdrew from the historical stage. This article carried on the thorough analysis for the reasons of the existence of electronic intermediaries, and discusses the new development space and prospect of new middlemen, from the perspective of information asymmetry of the network environment.
文摘One of the challenges in foreign language teaching, specifically teaching listening skill, is to create a low-anxiety classroom environment, since many learners believe listening induces anxiety. This study compares learners＇ anxiety in two different classrooms in which learners were instructed by two forms of artifacts： materializing and verbalizing. The Foreign Language Listening Anxiety Scale （FLLAS） scores before and after a 13-week experimental treatment course were used to compare learners＇ anxiety before and after receiving intervention by two means. In this study, the lower score of anxiety was for the group which did verbalization practice in the class; however, both groups showed the same performance on listening test.
