Investigating the Health of a Rice Field Ecosystem Using Thermodynamic Extremal Principles

This study investigates the dynamic behaviour of a rice field ecosystem and aims to define its integral features using the stability concept of an ecological goal function. This function is based on the extremal principles of thermodynamics, which assume that certain energetic processes of ecosystems—such as the rate of exergy destruction—are directed by the self-organizing informatics of the systems towards maxima or minima.  In our study, we exploit the availability of substantially long time-series data relating to a rice field ecosystem to gain an evocative understanding of its growth trajectory in light of the thermodynamic principles. We accomplished this by constructing a model based on the STELLA 9.0 software and calculating the extremal values of growth rates (storage) and those of exergy destruction and entropy creation. The results showed that the values of both maximum dissipation and maximum exergy progressed apace with that of maximum storage till the maturation of rice and became stable thereafter, whereas maximum residence time and maximum specific dissipation values initially decreased before their asymptotic rise. A similar pattern was also observed for the maximum specific exergy. However, the maximum power dissipation curve followed a highly fluctuated course before becoming stable on the maturation of rice

Coordination-Driven Fluorescent J‑Aggregates in a Perylenetetracarboxylate-Based MOF: Permanent Porosity and Proton Conductivity

Here we report the synthesis and structural characterizations of a new 3D functional metal–organic framework {[K₈(PTC)₂(H₂O)_1.5]·4H₂O}_<i>n</i> formed by the self-assembly of K^I and chromophoric linker perylenetetracarboxylate (PTC). The structure determination shows a 3D pillared-layer framework, where perylene cores are arranged in an unusual end-to-end off-slipped and zigzag arrangement directed by K^I–carboxylate bonding. Photophysical studies revealed a broad absorption band with λ_max of 531 nm and bathochromically shifted red emission centered at 655 nm. This characteristic emission has been assigned due to J-coupling of the PTC linkers in the solid state. The framework contains 1D water-filled channel, and the desolvated framework shows permanent porosity, “as realized by type-I CO₂ adsorption profile at 195 K. Interestingly, the guest and coordinated water molecules in the framework are connected via H-bonding and based on these characteristics, the framework was further exploited for proton conduction. It shows remarkable conductivity of 1 × 10^–3 S cm^–1 under ambient conditions (98% RH) with low activation energy

Coordination-Driven Fluorescent J‑Aggregates in a Perylenetetracarboxylate-Based MOF: Permanent Porosity and Proton Conductivity

Here we report the synthesis and structural characterizations of a new 3D functional metal–organic framework {[K₈(PTC)₂(H₂O)_1.5]·4H₂O}_<i>n</i> formed by the self-assembly of K^I and chromophoric linker perylenetetracarboxylate (PTC). The structure determination shows a 3D pillared-layer framework, where perylene cores are arranged in an unusual end-to-end off-slipped and zigzag arrangement directed by K^I–carboxylate bonding. Photophysical studies revealed a broad absorption band with λ_max of 531 nm and bathochromically shifted red emission centered at 655 nm. This characteristic emission has been assigned due to J-coupling of the PTC linkers in the solid state. The framework contains 1D water-filled channel, and the desolvated framework shows permanent porosity, “as realized by type-I CO₂ adsorption profile at 195 K. Interestingly, the guest and coordinated water molecules in the framework are connected via H-bonding and based on these characteristics, the framework was further exploited for proton conduction. It shows remarkable conductivity of 1 × 10^–3 S cm^–1 under ambient conditions (98% RH) with low activation energy