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Bark is an essential component of tree branches, yet its role in controlling branch-leached dissolved organic matter (DOM) characteristics remains unknown in forests. Here, we collected branches (about 1.5 cm in diameter) of two evergreen coniferous trees, two deciduous broadleaf trees, and three evergreen broadleaf trees from a subtropical forest in southern China, and subsequently used a bark removal experiment to determine the effects of bark on branch-derived DOM quantity and bioavailability. Regardless of tree type, the presence of bark reduced tree branch-leached dissolved organic carbon (DOC), dissolved total nitrogen (DTN), and dissolved total phosphorus (DTP) productions. Moreover, DOC, DTN, and DTP productions leached from the branches containing bark were always much lower than the expected values summed from barks and the branches without bark. The presence of bark increased DOM aromaticity in the broadleaf tree branch leachates but reduced DOM aromaticity in the coniferous tree branch leachates. During 42 days of incubation, the presence of bark decreased broadleaf tree branch-leached DOM bioavailability and the relative increments of aromaticity, whereas the opposite trends were observed for the coniferous tree branch-leached DOM. Tree branch-derived DOM bioavailability correlated negatively with SUVA254 values, but exhibited no relationship with either DOC:DTN ratio or DOC:DTP ratio. These observations highlight that tree bark can prevent DOM leaching from branches and regulate branch-leached DOM bioavailability via its effect on DOM aromaticity in subtropical forests. [ABSTRACT FROM AUTHOR]

China's Mars exploration mission has stimulated tremendous interest in planetary science exploration recently. To propose potential scientific research projects, this study presents a concept simulation for the measurement of Martian atmospheric winds using the Doppler Michelson interferometry technique. The simulation is based on the satellite instrument initially designed for the Dynamic Atmosphere Mars Observer (DYNAMO) project to measure vertical profiles of winds from the 1.27 μm airglow observations in the Martian atmosphere. A comprehensive DYNAMO measurement simulation forward model based on an orbit submodel, an atmospheric background field submodel, and an instrument submodel is developed using the Michelson equation. The simulated interferogram signal over the field of view (FOV) calculated by the forward model is associated with the filter transmittance function, column emission rate of airglow, wind velocity, temperature, and the Michelson phase. The agreement between the derived atmospheric signals from the simulated interferogram without altitude inversion and the input parameters used to initiate the forward model confirms the validity of the forward model. [ABSTRACT FROM AUTHOR]

Many studies have indicated that structural strain will be significantly influenced by temperature variations, and a good understanding of the effect of temperature on structural strain is essential. A structural health monitoring system has been installed in a typical Tibetan timber building to measure the structural strains and ambient temperature since 2012. This paper presents the correlation between temperature and strain data from the monitored structure. A method combining singular spectrum analysis and polynomial regression is proposed for modeling the temperature induced strains in the structure. Singular spectrum analysis is applied to smooth the temperature data, and the correlation between the resulting temperature time series and the measured strains is obtained by polynomial regression. Parameters of the singular spectrum analysis and the regression model are selected to have the least regression error. Results show that the proposed method has both good reproduction and prediction capabilities for temperature induced strains, and that the method is accurate and effective for eliminating the effect of temperature from the measured strain. A standardized Novelty Index based on the residual strain is also used for the condition assessment of the structure. [ABSTRACT FROM AUTHOR]