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Ecosystem light use efficiency (LUE) is a critical parameter in estimating CO2uptake by vegetation from climatological and satellite data. However, the spatiotemporal dynamics and biophysical regulations of ecosystem‐level LUE are not well understood, resulting in large uncertainties in the estimation of gross primary productivity (GPP) using LUE‐based models. In this study, we used eddy covariance to explore spatiotemporal variations and controls of LUE in four contrasting forest ecosystems (savanna, tropical rainforest, subtropical evergreen forest, and subalpine coniferous forest). Based on 27 site years of data, we found that (1) the multiyear mean LUE was 0.063, 0.251, 0.247, and 0.140 g C· mol photon−1in the four contrasting ecosystems, respectively; (2) the LUE in the wet season (May–October) was higher than that in the dry season in all studied ecosystems; (3) the leaf area index controlled GPP and LUE significantly and explained 74%, 29%, 54%, and 36% of the variation in GPP and 51%, 19%, 41%, and 54% of the variation in LUE in the four contrasting ecosystems, respectively; (4) path analysis revealed the critical roles of GPP and vapor pressure deficit in controlling LUE in these four forest ecosystems; and (5) under warming scenarios, LUE may decrease in savanna but increase in the other three ecosystems, while decreasing precipitation (P) may reduce LUE in the ecosystems studied. This study improves our understanding of the influence of biophysical factors on LUE and demonstrates how LUE changes with variations in temperature, soil moisture, and leaf area index, thereby improving estimations of large‐scale carbon exchange/cycling. Evergreen broad‐leaved forest (EBF) ecosystem shows higher LUE than subalpine coniferous/savanna ecosystemsThe vapor pressure deficit (VPD) and leaf area index (LAI) largely determine the variability in LUEWarming might decrease LUE in the savanna ecosystem and may increase LUE in the other three ecosystems

The relationship between physical activity (PA) and cognition has received much attention recently. While evidence of improved cognition following PA has consistently been observed, the majority of studies have spotlighted aerobic exercise and the effects of other modes of PA, such as Tai Ji Quan, on cognition have received limited attention. This article provides a brief review of the literature concerning the influence of Tai Ji Quan on cognition in older adults, including those with intact cognition and those with cognitive impairment. In addition, this review proposes potential mechanisms (cardiovascular fitness, motor fitness, movement coordination, social interaction, and meditation statuses as well brain structure and function) evaluated from a neuroimaging perspective that may explain the Tai Ji Quan–cognition relationship. Finally, we present suggestions for future research. In conclusion, Tai Ji Quan, with its multi-faceted characteristics, shows promise as a mode of PA for enhancing cognition, as well as brain health, in older adults. Based on the findings in this review, further exploration of the effects of Tai Ji Quan on cognition in older adults is warranted.

In view of the present, the data acquisition system of the fault monitoring system is not perfect, so the data acquisition module of mechanical fault system of wind power generator is developed based on DSP, which better improves the on-line monitoring system. Firstly, the paper introduces the working principle of the module and the selection principle of set measuring point and monitoring point. Then, it introduces the design of hardware system in detail.

The integral velocity error at the head end and the tail end of wave movement of ships or offshore platforms are too great. By improving the forecasting technique based on frequency spectrum, the integral velocity errors are maximally corrected and the wave movement of ships or offshore platforms is successful forecasted longer time ahead of time. Measurement technique of ship wave movement based on accelerometers array will be practically used.

This paper describes the design of a portable formaldehyde detector instrumentation which is based on the C8051F021 microcontroller. Using the Dart sensors for detection of formaldehyde and AD8571 precision operational amplifier for signal amplification, this meter will achieve real-time detection of formaldehyde in the air. The instrument's low power consumption, intelligent and portable features are suitable for the rapid detection of formaldehyde in indoor air.

Pre-stressed spatial tubular truss system is adopted in steel roof truss structures of China International Exhibition Center New Venue. Bottom chord joints are multiplanar KK-joints consisting of chord with square hollow section and brace with circular hollow section. However, not only that relatively little research has been carried out on such joints, but also that no detailed design guidance on KK-type joints consisting of chord with square hollow section and brace with circular hollow section can be found Current design code for steel structure (GB 50017-2003). This paper reports the study into the strength of this type of KK-joints under axial loading. The numerical models were adopted, and several various geometric parameters which affect the strength and failure modes, were investigated. It was indicated that the geometric parameters affects significantly the ultimate capacity and failure modes of the joints. The varied relationship of the strength and failure mode with parameter varying was studied in detail. The results of the work presented provide initial discussion on behavior of this type of KK-joints and lay the foundation for a future large-scale parametric study and put out design formula.