Evaluating transfer velocity-wind speed relationship using a long-term series of direct eddy correlation CO2 flux measurements

Long-term observations of the marine atmospheric boundary layer were performed by an eddy correlation system, which was set-up on a platform in the Baltic Sea. In this experiment the three-dimensional wind vector and the turbulent fluxes of momentum, sensible and latent heat and CO₂ were measured for one and a half years. Simultaneously the CO₂ partial pressure p_CO2 in surface water was measured by a submersible autonomous moored instrument for CO₂ at the platform in 7-m depth. The high-resolution eddy correlation measurements of the atmospheric CO₂ flux F_CO2, together with the measurements of the CO₂ partial pressure differences between air and sea Δp_CO2 led to a long-term data set which provided the possibility to investigate the parameterization of the CO₂ transfer velocity k as a function of 10-m wind speed u in a statistical manner. From half-hour mean CO₂ fluxes and CO₂ partial pressure differences, k was calculated using k = F_CO2 / (K₀Δp_CO2), with K₀ the CO₂ solubility. The half-hour mean data points, used for the determination of the k–u parameterization, show large scatter. However, assuming a linear, quadratic dependency the analysis yields: k₆₆₀ = 0.365u² + 0.46u (k at 20 °C and salinity 35 psu) with a correlation coefficient of r² = 0.81. The large scatter indicates that the kinetics of the air–sea CO₂ transfer velocity is not only a function of the wind speed alone, but might also be controlled by other environmental parameters and mechanisms, such as sea state and surface coverage with surfactants.     

瑞士罐车装上脱轨检测器

20世纪 90年代中期 ,罐车经过 2次 (1次是在瑞士联邦铁路苏黎世附近的阿福尔特恩 ,另 1次是在洛桑 )严重脱轨事故之后 ,瑞士油料工业和私有罐车主决心不让类似事故再次发生。虽然Esso货车公司在 2次事故中均没有受到损失 ,但在与其工业伙伴商议后 ,仍决定逐步安装脱轨检测器。要想使罐车不发生任何事故是不现实的 ,脱轨检测则可大大减少重大事故的危险性。瑞士早在 1994年就率先作出决定 ,又于1996年 2月安装了第一批检测器并进行试运行。经过对各种检测装置进行测定 ,最终选用Knorr Bremse公司的ETD10 0型气压脱轨检测器。这种装置通过…     

THE EFFECTS OF POLYAMINE ANALOGUES AND POLYAMINE TOXIN ON EXPRESSED KIR 2.1 CHANNEL

Inward rectifying potassium channels(Kir)are presentin a wide variety of cell types,includingmuscles,neurons,eggs and endothelial cells.Theyconduct cations more easily in the inward directionthan in the outward direction,and this property isimportant for maintaining the resting membranepotential near the K equilibrium potential (Ek) ,and for permitting long depolarizing responses[1,2 ] .The property of strong inward rectifier K channel(Kir2 .1 ) has been previously attributed to intra-cellul…