An accurate accounting of land surface emissivity(ε) is important both for the retrieval of surface temperatures and the calculation of the longwave surface energy budgets.Since ε is one of the important parameteriz...An accurate accounting of land surface emissivity(ε) is important both for the retrieval of surface temperatures and the calculation of the longwave surface energy budgets.Since ε is one of the important parameterizations in land surface models(LSMs),accurate accounting also improves the accuracy of surface temperatures and sensible heat fluxes simulated by LSMs.In order to obtain an accurate emissivity,this paper focuses on estimating ε from data collected in the hinterland of Taklimakan Desert by two different methods.In the first method,ε was derived from the surface broadband emissivity in the 8–14 μm thermal infrared atmospheric window,which was determined from spectral radiances observed by field measurements using a portable Fourier transform infrared spectrometer,the mean ε being 0.9051.The second method compared the observed and calculated heat fluxes under nearneutral atmospheric stability and estimated ε indirectly by minimizing the root-mean-square difference between them.The result of the second method found a mean value of 0.9042,which is consistent with the result by the first method.Although the two methods recover ε from different field experiments and data,the difference of meanvalues is 0.0009.The first method is superior to the indirect method,and is also more convenient.展开更多
Simulated adsorptive experiments using the axletree and lubricating oil containing anticorrosion additive were conducted,and the UV absorbance of the lubricating oil before and after the adsorptive experiments was mea...Simulated adsorptive experiments using the axletree and lubricating oil containing anticorrosion additive were conducted,and the UV absorbance of the lubricating oil before and after the adsorptive experiments was measured.Through the UV spectral measurements the difference in UV absorbance of the lubricating oil before and after the adsorptive experiments was identified,the adsorbed quantity of anticorrosion additive in the interfacial film between lubricating oil and bearing was calculated using the Lambert-Bell principle to verify the adsorption of corrosion inhibitor on the surface of friction pairs.Adsorption experiments on lubricating oil containing both antiwear and anticorrosion additives were carried out and the UV absorbance of lubricating oil samples before and after the experiments was measured to determine the difference in the UV absorbance among lubricating oil samples with the same mass fraction of anticorrosion additive and different mass fractions of antiwear additive.By measuring the ultraviolet spectral absorbance of lubricating oil samples and calculating the adsorbed quantity of anticorrosion additive in the interfacial film it was possible to determine the influence of antiwear additive on the quantity of adsorbed anticorrosion additive on the surface of friction pairs and verify the competitive adsorption relationship between the antiwear additive and the anticorrosion additive.展开更多
基金sponsored by the National Natural Science Foundation of China (Grant No. 41265002, 41130641, and 41175140)the Special Fund for Meteorology-scientific Research in the Public Interest of China (Grant No. GYHY201306066)
文摘An accurate accounting of land surface emissivity(ε) is important both for the retrieval of surface temperatures and the calculation of the longwave surface energy budgets.Since ε is one of the important parameterizations in land surface models(LSMs),accurate accounting also improves the accuracy of surface temperatures and sensible heat fluxes simulated by LSMs.In order to obtain an accurate emissivity,this paper focuses on estimating ε from data collected in the hinterland of Taklimakan Desert by two different methods.In the first method,ε was derived from the surface broadband emissivity in the 8–14 μm thermal infrared atmospheric window,which was determined from spectral radiances observed by field measurements using a portable Fourier transform infrared spectrometer,the mean ε being 0.9051.The second method compared the observed and calculated heat fluxes under nearneutral atmospheric stability and estimated ε indirectly by minimizing the root-mean-square difference between them.The result of the second method found a mean value of 0.9042,which is consistent with the result by the first method.Although the two methods recover ε from different field experiments and data,the difference of meanvalues is 0.0009.The first method is superior to the indirect method,and is also more convenient.
文摘Simulated adsorptive experiments using the axletree and lubricating oil containing anticorrosion additive were conducted,and the UV absorbance of the lubricating oil before and after the adsorptive experiments was measured.Through the UV spectral measurements the difference in UV absorbance of the lubricating oil before and after the adsorptive experiments was identified,the adsorbed quantity of anticorrosion additive in the interfacial film between lubricating oil and bearing was calculated using the Lambert-Bell principle to verify the adsorption of corrosion inhibitor on the surface of friction pairs.Adsorption experiments on lubricating oil containing both antiwear and anticorrosion additives were carried out and the UV absorbance of lubricating oil samples before and after the experiments was measured to determine the difference in the UV absorbance among lubricating oil samples with the same mass fraction of anticorrosion additive and different mass fractions of antiwear additive.By measuring the ultraviolet spectral absorbance of lubricating oil samples and calculating the adsorbed quantity of anticorrosion additive in the interfacial film it was possible to determine the influence of antiwear additive on the quantity of adsorbed anticorrosion additive on the surface of friction pairs and verify the competitive adsorption relationship between the antiwear additive and the anticorrosion additive.
