生态位理论视角下我国青年数字素养发展路径

提升青年数字素养既是青年适应数字社会的必然之举,也是网络强国建设的应有之义。文章基于生态位理论,将我国青年数字素养作为独立的生态有机体,通过分析青年数字素养的生态位及其构成,厘清青年数字素养生态位发展的技术因子、空间因子和环境因子,展示数字素养的演进脉络。当前我国青年数字素养存在数字堕距、数字鸿沟和数字壁垒等限制因子,应从消解发展堕距、技术堕距和身份堕距中的数字堕距,弥合地理空间、社会空间和网络空间的数字鸿沟,破除竞争环境和共生环境中的数字壁垒的发展路径出发,以期巩固既有生态位,扩大基础生态位,寻求共生生态位。

当下人文生态及其文化工业语境（上）──当代音乐对后现代主义文化约定的历史承诺

自从历史进入本世纪７０年代以来，包括音乐在内的艺术文化，发生了一系列超常生态的骤变，此前相对稳定的主导型单元文化取向遂被多元并存型文化取向的频繁转型所取代，处在文化工业语境中的音乐文化，一方面表现为传统文化言路的断裂；另方面又表现为对传统文化的追寻和＂回归＂，以实现其对后现代主义文化约定的历史承诺。

The oceanic cycles of the transition metals and their isotopes

The stable isotope systems of the transition metals potentially provide constraints on the current and past operation of the biological pump,and on the state of ocean redox in Earth history.Here we focus on two exemplar metals,nickel(Ni)and zinc(Zn).The oceanic dissolved pool of both elements is isotopically heavier than the known inputs,implying an output with light isotope compositions.The modern oceanic cycle of both these elements is dominated by biological uptake into photosynthesised organic matter and output to sediment.It is increasingly clear,however,that such uptake is associated with only very minor isotope fractionation.We suggest that the isotopic balance is instead closed by the sequestration of light isotopes to sulphide in anoxic and organic-rich sediments,so that it is ocean chemistry that controls these isotope systems,and suggesting a different but equally interesting array of questions in Earth history that can be addressed with these systems.