本文按 ASTMG 48—76标准推荐的10%FeCl_3溶液完全浸入法研究了 Ti 稳定的/8—8不锈钢在55℃—300℃范围内热处理的点蚀性能,提出了点蚀的敏感温度区间;研究了冷一变形及其蚀后的时效处理对点蚀性能的影响,观察了点蚀的形貌并指出了点...本文按 ASTMG 48—76标准推荐的10%FeCl_3溶液完全浸入法研究了 Ti 稳定的/8—8不锈钢在55℃—300℃范围内热处理的点蚀性能,提出了点蚀的敏感温度区间;研究了冷一变形及其蚀后的时效处理对点蚀性能的影响,观察了点蚀的形貌并指出了点蚀起源.从而提出了改善这材料抗点蚀性能的加工热处理途径.展开更多
Four-year-old Pinus sylvestriformis were exposed for four growing seasons in open top chambers to ambient CO2 concentration (approx. 350 μmol·mol-1) and high CO2 concentrations (500 and 700 μmol·mol-1) at ...Four-year-old Pinus sylvestriformis were exposed for four growing seasons in open top chambers to ambient CO2 concentration (approx. 350 μmol·mol-1) and high CO2 concentrations (500 and 700 μmol·mol-1) at Research Station of Changbai Mountain Forest Ecosystems, Chinese Academy of Sciences at Antu Town, Jilin Province, China (42oN, 128oE). Stomatal response to elevated CO2 concentrations was examined by stomatal conductance (gs), ratio of intercellular to ambient CO2 concentration (ci/ca) and stomatal number. Reciprocal transfer experiments of stomatal conductance showed that stomatal conductance in high-[CO2]-grown plants increased in comparison with ambient-[CO2]-grown plants when measured at their respective growth CO2 concentration and at the same measurement CO2 concentration (except a reduction in 700 μmol·mol-1 CO2 grown plants compared with plants on unchambered field when measured at growth CO2 concentration and 350 μmol·mol-1CO2). High-[CO2]-grown plants exhibited lower ci/ca ratios than ambient-[CO2]-grown plants when measured at their respective growth CO2 concentration. However, ci/ca ratios increased for plants grown in high CO2 concentrations compared with control plants when measured at the same CO2 concentration. There was no significant difference in stomatal number per unit long needle between elevated and ambient CO2. However, elevated CO2 concentrations reduced the total stomatal number of whole needle by the decline of stomatal line and changed the allocation pattern of stomata between upper and lower surface of needle.展开更多
Ad hoc网络是一种无有线基础设施支持的移动网络,它与internet相比存在许多差异,不仅有网络拓扑结构的不同,还存在通信方式的不同,因此两者的互联是一具有挑战性的课题。Ad hoc网络结点要进行internet连接,必须寻找internet网关,如何发...Ad hoc网络是一种无有线基础设施支持的移动网络,它与internet相比存在许多差异,不仅有网络拓扑结构的不同,还存在通信方式的不同,因此两者的互联是一具有挑战性的课题。Ad hoc网络结点要进行internet连接,必须寻找internet网关,如何发现和维持与网关的连接以及如何切换到一个更合适的相邻网关是这个问题的关键。文章在主动式、被动式、混合式及AODV路由协议中Hello消息机制的基础上,讨论了一种新的网关发现方法,即利用Hello消息机制,通过改进网关和节点对Hello消息的处理所得到的新的网关发现机制,仿真结果显示在一定网络环境下能够基本满足adhoc接入internet的需要。展开更多
文摘本文按 ASTMG 48—76标准推荐的10%FeCl_3溶液完全浸入法研究了 Ti 稳定的/8—8不锈钢在55℃—300℃范围内热处理的点蚀性能,提出了点蚀的敏感温度区间;研究了冷一变形及其蚀后的时效处理对点蚀性能的影响,观察了点蚀的形貌并指出了点蚀起源.从而提出了改善这材料抗点蚀性能的加工热处理途径.
文摘Four-year-old Pinus sylvestriformis were exposed for four growing seasons in open top chambers to ambient CO2 concentration (approx. 350 μmol·mol-1) and high CO2 concentrations (500 and 700 μmol·mol-1) at Research Station of Changbai Mountain Forest Ecosystems, Chinese Academy of Sciences at Antu Town, Jilin Province, China (42oN, 128oE). Stomatal response to elevated CO2 concentrations was examined by stomatal conductance (gs), ratio of intercellular to ambient CO2 concentration (ci/ca) and stomatal number. Reciprocal transfer experiments of stomatal conductance showed that stomatal conductance in high-[CO2]-grown plants increased in comparison with ambient-[CO2]-grown plants when measured at their respective growth CO2 concentration and at the same measurement CO2 concentration (except a reduction in 700 μmol·mol-1 CO2 grown plants compared with plants on unchambered field when measured at growth CO2 concentration and 350 μmol·mol-1CO2). High-[CO2]-grown plants exhibited lower ci/ca ratios than ambient-[CO2]-grown plants when measured at their respective growth CO2 concentration. However, ci/ca ratios increased for plants grown in high CO2 concentrations compared with control plants when measured at the same CO2 concentration. There was no significant difference in stomatal number per unit long needle between elevated and ambient CO2. However, elevated CO2 concentrations reduced the total stomatal number of whole needle by the decline of stomatal line and changed the allocation pattern of stomata between upper and lower surface of needle.
