封闭生态系统

设施生产属人为控制下的封闭式生态系统，对无公害蔬菜的生产有其特殊的要求和技术。

Protective production belongs to occluded biosystem in man-made control , and there are especial need and technology in production of pollution-free vegetables .

如果我们过分痴迷于Twitter或Facebook封闭的环形生态系统，我们就会很容易忘记一些真正重要的事情，比如贫困率正在上升；社会阶层固化，而且呈下行流动；数百万美国人正陷入长期失业之中，欧洲和世界其他地方的失业者甚至更多；

When we become too obsessed with our closed , circular Twitter or Facebook ecosystem , we can easily forget that poverty is on the rise , downward mobility is trending upward , millions of people in the United States and even more in Europe and around the world have fallen into chronic unemployment ,

艾比湖沿岸作为新疆干旱区生态系统中内陆封闭绿洲子生态系统，生态环境脆弱，随着大规模的水土开发的进行，产生了诸多的生态环境问题。

With the water and soil exploitation in Large scale , a lot of eco-environmental problems appeared in the oasis in the combination regions of mountain area and basin .

目的是要在清晰展现农村贫困的空间分布条件下，论证地理环境的封闭性与生态系统的脆弱性对贫困的影响；（2）贫困的动态化研究。

First is the research on relation between poverty and environment to prove the influence on poverty caused by closeness of geographical environment and ecosystem vulnerability with a clear display of spatial distribution of rural poverty .