郊区化

The labor force in the tertiary industry disperses from urban core to its edge area within a distance of 15 km; oppositely it has a centralizing trend to inner city out of a distance of 15 km, especially in exurban area.

第二、三产业从业劳动力的分布变动互不相同：第二产业主要表现为由中心城区向郊区扩散的较大范围的单向均衡化变动；第三产业从业劳动力空间分布的变动则相对更向中心城区集聚，表现为在距离市中心15km圈内由都心区向其边缘区扩散、15km圈以外地区特别是远郊区则反呈趋向中心城区的集中化变动。

This thesis is the empirical research for the job mobility in suburb of Pudong based on analyzing the questionnaire survey data from the Pudong New District Rural committee at Mar.

同时随着农村城市化的进程的推进，农民市民化已经被提到议事日程。在这个背景下，研究郊区劳动力的职业流动具有很重要的理论和现实意义。

This first phase of mass-scale suburbanization was reinforced by the simultaneous emergence of the urban Middle Class, whose desires for homeownership in neighborhoods far from the aging inner city were satisfied by the developers of singlesingle-family housing tracts.

此时城市中产阶级的出现进一步加强了第一此时城市中产阶级的出现进一步加强了第一波大规模郊区这些中产阶级希望在远离老旧城市的地区拥有住宅，化。这些中产阶级希望在远离老旧城市的地区拥有住宅，的开发者满足了他们的愿望。单一家庭住宅地区的开发者满足了他们的愿望。

However, the urbanization of metropolitan areas is increasing and urban sprawl usually occurs in these urbanized areas.

然而，随者大都市区域的都市化正在快速增加，而向郊区急速扩展。

Beijing environmental problems hold severe, and atmospheric and water pollute, soil and water loss, hot island and yawp are leading problems,and take on territorial characteristic. Based on research on relativity between urban forest and these environmental problems, urban forest can effective improve environmental quality in Beijing. And for the aim of improve environmental quality, Beijing forest overlay should attain 35% at least in citywide range, and local-areas being severe environmental problem should be provided with higher forest overlay.5. Through the study on urban forest needed capacity, Beijing's forest coverage is up to par in citywide range, but montanic forest coverage, plain covered with trees and average forest area are lacking, and CO2 and O2 balance is incapable;form the point of heat and balance CO2 and O2 balance,urban forest the city zone and suburb is lack. There is urban forest developmental potential space,but the city zone and suburb area need be compensated form urban forest in circumjacent region.6. On the based of the above results and ecological network system, the author drived whole region into city area, plain and mountain area are needed at the point of planning thoughts of running-through forests and water .

根据城市森林与北京市主要环境问题的相关性分析，城市森林在改善这些环境问题中具有重要的作用，为有效改善这些环境问题，整个北京市域范围内森林覆盖率至少达到35%，并且分布比较均匀，环境问题严重的局部区域需要不同程度增加森林覆盖率。5、通过对北京市城市森林需求量研究发现，虽然在市域范围内北京森林覆盖率达到了国家标准，但是山区森林覆盖率、平原林木覆盖率、城区人均森林面积不足；从区域热平衡和碳氧平衡角度分析，城区和郊区不能满足本区域的城市森林需求量，虽然北京市城市森林具有一定的发展潜力，整体上基本可以满足城市需要，但是这些区域需要依靠周边区域城市森林的补偿。6、根据以上的研究结果，以中国森林生态网络体系建设的点、线、面布局理念为指导，以&林网化——水网化&作为优化理念，将北京市整个市域划分为城区近郊区及其辐射区域，平原区和山区三大区域，依据三大区域特点进行城市森林布局优化。

Lessons from abroad to see: City of the early stage of large influx of population in urban centers and urban central area of environmental degradation; late urbanization, the population of the city center from the poor to move to the outskirts of the environment good by This resulted in the city center "hollowing out" phenomenon, so have the anti-over to "the revitalization of the central area."

从国外的经验教训看：城市的早期阶段大量涌入的人口在城市中心和城市中心区的环境退化；后期城市化，人口的城市中心从穷国转移到郊区的环境好了这导致了城市中心&空洞化&现象，因此有反到&振兴中部地区。&

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。