Estimation of the leaf chlorophyll content using multiangular spectral reflectance factor.

Chlorophyll is one of the primary pigments of plant leaves, and changes in its content can be used to characterize the physiological status of plants. Spectral indices have been devised and validated for estimating leaf chlorophyll content (LCC). However, most of the existing spectral indices do not consider the influence of angular reflection on the accuracy of the LCC estimation. In this study, the spectral reflectance factors of leaves from three plant species were measured from several observations in the principal plane. The relationship between the existing spectral indices and the LCC from different directions suggests that the directional reflection of a leaf surface impacts the accuracy of its LCC estimation. Subsequently, the ratio of reflectance differences, that is, the modified Datt index, was tested to reduce the directional reflection effect when predicting LCC. Our results indicated that the modified Datt index not only estimated LCC with high accuracy for all observation directions and plant species but also consistently predicted the LCC of each species in individual observation directions. Our method opens the possibility for optical detection of LCC using multiangular spectral reflection, which is convenient for plant science studies focused on the variation in LCC.

Parental Involvement and Children's Subjective Well-Being: Mediating Roles of the Sense of Security and Autonomous Motivation in Chinese Primary School Students.

Parental involvement may influence the subjective well-being of primary school students, but the specific mechanisms remain unclear. This study explores the mechanisms between parental involvement and primary school students' subjective well-being. The current study investigated 340 fifth and sixth grade students and their parents from a primary school using the Parental Education Involvement Behavior Scale, the Well-Being Scale, the Sense of Security Scale, and the Learning Self-Regulation Scale. We found that (1) sense of security plays a complete mediating role between parental involvement and primary school students' subjective well-being; (2) autonomous motivation has a marginal mediating effect between parental involvement and subjective well-being of primary school students; and (3) sense of security and autonomous motivation play a chain mediating role between parents' educational involvement and primary school students' well-being. In conclusion, parental involvement appears to contribute to primary school children's subjective well-being, and this effect may be mediated individually and sequentially by the children's sense of security and autonomous motivation.

Mechanism and Data-Driven Dual Estimation of Coupling Hydraulic-Thermal States for Steam Heating Networks Considering Multi-Time-Scale Characteristics.

For a steam heating network (SHN), which is one of the most important parts of the integrated energy systems in an industrial park, it is essential to provide accurate and reliable estimation of hydraulic and thermal states, to ensure its operational safety and economy. Considering two different time-scale characteristics of the hydraulic and thermal processes in the SHN, this article proposes a mechanism and data-driven dual estimation method for the coupling hydraulic-thermal dynamic states. Due to the fact that the existing coupled estimation methods with one time scale may suffer from heavy computational burden, a data-driven dual sequential DSE method of the SHN is proposed based on the two-time scales, in which the dynamics of slow thermal states can also be captured when performing the SE of the fast hydraulic process. Furthermore, to improve the computational and communicational efficiency, a distributed interaction strategy based on the nodal transformation matrix is designed for large-scale steam systems. To verify the effectiveness of the proposed method, a single pipeline system and two real-world industrial superheated steam networks are employed. Compared to other state-of-the-art methods, the proposed method achieves the best tradeoff between the estimation accuracy and computational efficiency.