哪位能帮忙分析下面一段GC日志，包括过程、相关意义等等，谢谢。

<af type="nursery" id="12502" timestamp="Aug 17 13:06:16 2012" intervalms="56661.377">
  <minimum requested_bytes="56" />
  <time exclusiveaccessms="0.186" meanexclusiveaccessms="0.186" threads="0" lastthreadtid="0x000000011A422200" />
  <refs soft="3485" weak="4250" phantom="20" dynamicSoftReferenceThreshold="25" maxSoftReferenceThreshold="32" />
  <nursery freebytes="0" totalbytes="180147200" percent="0" />
  <tenured freebytes="391697648" totalbytes="805306368" percent="48" >
    <soa freebytes="391697648" totalbytes="805306368" percent="48" />
    <loa freebytes="0" totalbytes="0" percent="0" />
  </tenured>
  <gc type="scavenger" id="12501" totalid="12562" intervalms="56661.690">
    <flipped objectcount="336837" bytes="18612656" />
    <tenured objectcount="1055632" bytes="54551488" />
    <finalization objectsqueued="473" />
    <scavenger tiltratio="67" />
    <nursery freebytes="161126536" totalbytes="180239360" percent="89" tenureage="7" />
    <tenured freebytes="335671256" totalbytes="805306368" percent="41" >
      <soa freebytes="335671256" totalbytes="805306368" percent="41" />
      <loa freebytes="0" totalbytes="0" percent="0" />
    </tenured>
    <time totalms="112.590" />
  </gc>
  <nursery freebytes="161061000" totalbytes="180239360" percent="89" />
  <tenured freebytes="335671256" totalbytes="805306368" percent="41" >
    <soa freebytes="335671256" totalbytes="805306368" percent="41" />
    <loa freebytes="0" totalbytes="0" percent="0" />
  </tenured>
  <refs soft="3468" weak="3960" phantom="20" dynamicSoftReferenceThreshold="25" maxSoftReferenceThreshold="32" />
  <time totalms="113.046" />
</af>

这个是IBM J9 VM的GC日志吧？请参考IBM官网上的文档，以及用IBM GCMV来查看这种GC日志的内容：http://www.ibm.com/developerworks/java/jdk/tools/gcmv/