Ecosystems in Mediterranean climate regions are projected to undergo considerable changes as a result of shifting climate, including from extreme drought and heat events. A severe and sudden dieback event, occurring i...Ecosystems in Mediterranean climate regions are projected to undergo considerable changes as a result of shifting climate, including from extreme drought and heat events. A severe and sudden dieback event, occurring in regionally significant Eucalyptus gomphocephala woodland in Western Australia, coincided with extreme drought and heat conditions in early 2011. Using a combination of remote sensing and field- based approaches, we characterized the extent and severity of canopy dieback following the event, as well as highlighted potential predisposing site factors. An estimated 500 ha of woodland was severely affected between February and March 2011. Tree foliage rapidly discolored and died over this period. In the af-fected portion of the woodland, approximately 90% of trees greater than 20 cm DBH were impacted, while in the adjacent unaffected woodland 6% showed signs of damage. Tree density in the unaffected area had approximately 4.5 times more trees than the affected woodland. Precipitation drainage patterns are thought to explain the difference between affected and unaffected woodland. Dropping groundwater levels, a relatively shallow soil profile, and extreme drought and heat in 2010-2011 are thought to predispose water-shedding sites to drought-triggered canopy dieback during extended periods of dryness. Tracking forest health changes in response to severe disturbance is an important key to deciphering past and future vegetation change.展开更多
为了提高汽车覆盖件模具设计变更管理的效率,在其开发过程的基础上,将汽车覆盖件模具的更改分为主动变更和被动变更,并讨论了两类变更的特点,然后分析了不同阶段发生的设计变更对模具开发进度产生的影响.提出了汽车覆盖件模具的设计变...为了提高汽车覆盖件模具设计变更管理的效率,在其开发过程的基础上,将汽车覆盖件模具的更改分为主动变更和被动变更,并讨论了两类变更的特点,然后分析了不同阶段发生的设计变更对模具开发进度产生的影响.提出了汽车覆盖件模具的设计变更流程,并对有关问题进行了探讨,从技术实现的角度,将覆盖件模具的设计更改分为属性、DL(D ie L ayer)数模和结构变更三类,并给出了设计变更在PLM(P roduct L ife cycle M anagem en t)系统T eam cen ter中的实现方法.展开更多
文摘Ecosystems in Mediterranean climate regions are projected to undergo considerable changes as a result of shifting climate, including from extreme drought and heat events. A severe and sudden dieback event, occurring in regionally significant Eucalyptus gomphocephala woodland in Western Australia, coincided with extreme drought and heat conditions in early 2011. Using a combination of remote sensing and field- based approaches, we characterized the extent and severity of canopy dieback following the event, as well as highlighted potential predisposing site factors. An estimated 500 ha of woodland was severely affected between February and March 2011. Tree foliage rapidly discolored and died over this period. In the af-fected portion of the woodland, approximately 90% of trees greater than 20 cm DBH were impacted, while in the adjacent unaffected woodland 6% showed signs of damage. Tree density in the unaffected area had approximately 4.5 times more trees than the affected woodland. Precipitation drainage patterns are thought to explain the difference between affected and unaffected woodland. Dropping groundwater levels, a relatively shallow soil profile, and extreme drought and heat in 2010-2011 are thought to predispose water-shedding sites to drought-triggered canopy dieback during extended periods of dryness. Tracking forest health changes in response to severe disturbance is an important key to deciphering past and future vegetation change.
文摘为了提高汽车覆盖件模具设计变更管理的效率,在其开发过程的基础上,将汽车覆盖件模具的更改分为主动变更和被动变更,并讨论了两类变更的特点,然后分析了不同阶段发生的设计变更对模具开发进度产生的影响.提出了汽车覆盖件模具的设计变更流程,并对有关问题进行了探讨,从技术实现的角度,将覆盖件模具的设计更改分为属性、DL(D ie L ayer)数模和结构变更三类,并给出了设计变更在PLM(P roduct L ife cycle M anagem en t)系统T eam cen ter中的实现方法.
