There was heterogeneous distribution in stomatal conductance (g-s) and stomatal aperture for both high- and low-light leaves of Ligustrum sinense Lour. in four designated positions within a leaf. Linear or exponential...There was heterogeneous distribution in stomatal conductance (g-s) and stomatal aperture for both high- and low-light leaves of Ligustrum sinense Lour. in four designated positions within a leaf. Linear or exponential or polynomial relationships between g-s and stomatal aperture were found when regression of g-s and stomatal aperture was established. Statistical analysis revealed that the relationship between g-s and stomatal aperture for high-light leaves was more significant than that of low-light leaves. A linear relationship between g-s and stomatal aperture existed in both positions 1 and 3 for both high- and low-light leaves. The stomatal density of the low-light leaves was much lower than that of the high-light leaves. The sensitivity of stomata to changing environment for high-light leaves was higher than that for low-light leaves, which may also relate to the higher stomatal density for the high-light leaves.展开更多
The equations governing wind-induced internal pressure responses for a two-compartment building with a dominant opening and background porosity were derived.The unsteady form of the Bernoulli equation,the law of mass ...The equations governing wind-induced internal pressure responses for a two-compartment building with a dominant opening and background porosity were derived.The unsteady form of the Bernoulli equation,the law of mass conservation,and adiabatic equation were used for the derivation.The precision of the governing equations was verified by a wind tunnel test on a rigid model of a low-rise building.The results show that the governing equations can effectively analyze the wind-induced internal pressure responses.The internal pressure responses in both compartments are suppressed due to the additional damping provided by background porosity.The responses of internal pressure in both compartments,especially in the compartment without an external opening,decrease with increased lumped leakage area.展开更多
The effects of polyurethane sponge pretreatment and slurry compositions on the slurry loading in precursor were discussed,and the performances of stainless steel foams prepared from precursors with different slurry lo...The effects of polyurethane sponge pretreatment and slurry compositions on the slurry loading in precursor were discussed,and the performances of stainless steel foams prepared from precursors with different slurry loadings and different particle sizes of the stainless steel powder were also investigated.The experimental results show that the pretreatment of sponge with alkaline solution is effective to reduce the jam of cells in precursor and ensure the slurry to uniformly distribute in sponge,and it is also an effective method for increasing the slurry loading in precursor;the mass fraction of additive A and solid content in slurry greatly affect the slurry loading in precursor,when they are kept in 9%-13% and 52%-75%,respectively,the stainless steel foam may hold excellent 3D open-cell network structure and uniform muscles;the particle size of the stainless steel powder and the slurry loading in precursor have great effects on the bending strength,apparent density and open porosity of stainless steel foam;when the stainless steel powder with particle size of 44 μm and slurry loading of 0.5 g/cm3 in precursor are used,a stainless steel foam can be obtained,which has open porosity of 81.2%,bending strength of about 51.76 MPa and apparent density of about 1.0 g/cm3.展开更多
文摘There was heterogeneous distribution in stomatal conductance (g-s) and stomatal aperture for both high- and low-light leaves of Ligustrum sinense Lour. in four designated positions within a leaf. Linear or exponential or polynomial relationships between g-s and stomatal aperture were found when regression of g-s and stomatal aperture was established. Statistical analysis revealed that the relationship between g-s and stomatal aperture for high-light leaves was more significant than that of low-light leaves. A linear relationship between g-s and stomatal aperture existed in both positions 1 and 3 for both high- and low-light leaves. The stomatal density of the low-light leaves was much lower than that of the high-light leaves. The sensitivity of stomata to changing environment for high-light leaves was higher than that for low-light leaves, which may also relate to the higher stomatal density for the high-light leaves.
基金Project(90715040) supported by the Major Research Program of the National Natural Science Foundation of ChinaProject(50878159) supported by the General Program of the National Natural Science Foundation of China
文摘The equations governing wind-induced internal pressure responses for a two-compartment building with a dominant opening and background porosity were derived.The unsteady form of the Bernoulli equation,the law of mass conservation,and adiabatic equation were used for the derivation.The precision of the governing equations was verified by a wind tunnel test on a rigid model of a low-rise building.The results show that the governing equations can effectively analyze the wind-induced internal pressure responses.The internal pressure responses in both compartments are suppressed due to the additional damping provided by background porosity.The responses of internal pressure in both compartments,especially in the compartment without an external opening,decrease with increased lumped leakage area.
基金Project(06SK2011) supported by the Science and Technology Program of Hunan Province,China
文摘The effects of polyurethane sponge pretreatment and slurry compositions on the slurry loading in precursor were discussed,and the performances of stainless steel foams prepared from precursors with different slurry loadings and different particle sizes of the stainless steel powder were also investigated.The experimental results show that the pretreatment of sponge with alkaline solution is effective to reduce the jam of cells in precursor and ensure the slurry to uniformly distribute in sponge,and it is also an effective method for increasing the slurry loading in precursor;the mass fraction of additive A and solid content in slurry greatly affect the slurry loading in precursor,when they are kept in 9%-13% and 52%-75%,respectively,the stainless steel foam may hold excellent 3D open-cell network structure and uniform muscles;the particle size of the stainless steel powder and the slurry loading in precursor have great effects on the bending strength,apparent density and open porosity of stainless steel foam;when the stainless steel powder with particle size of 44 μm and slurry loading of 0.5 g/cm3 in precursor are used,a stainless steel foam can be obtained,which has open porosity of 81.2%,bending strength of about 51.76 MPa and apparent density of about 1.0 g/cm3.
