钢结构构件的刚度是通过容许长细比[λ]来保证的,以下关于容许长细比的规定哪一项是错误的()?
A、桁架和天窗架中受压的杆件,[λ]=150
B、受压的支撑杆件,[λ]=180
C、一般建筑结构中的桁架受拉杆件,[λ]=350
D、受拉构件在永久荷载与风荷载组合作用下受压时,[λ]=250
压力容器的紧螺栓联接中,若螺栓的预紧力和容器的压强不变,而仅将凸缘间的铜垫片换成橡胶垫片,则螺栓所受的总拉力Qb()和联接的紧密性()。
要删除行,行的所有者发出SetRequestPDU,把行的状态对象置为()
A、InvAliD
B、ValiD
C、CreAteRequest
D、UnDerCreAtion
Which Cisco CRS 4.0 server configuration task enables the Cisco CRS server to fail over to a secondary Cisco Unified CallManager when the primary Cisco Unified CallManager fails?()
A、The LDAP directory must have a secondary profile configured.
B、No special configuration is required. Cisco Unified CallManager maintains the failover.
C、The JTAPI provider on the Cisco CRS server must be configured with the secondary Cisco Unified CallManager IP address following the primary Cisco Unified CallManager IP address.
D、There must be a second JTAPI user configured with an alternate range of CTI ports.
中国的第一份数学刊物--《算学报》是由()创办的。
A、黄庆澄
B、孙诒让
C、陆善镇
作物对税点需求存在()和()两个关键时期。