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This is a continuation of the work initiated with a previous Special Issue entitles “Advanced Research in Pure and Applied Algebra” published in the MDPI journal Mathematics [...]

Membranes with fast and selective ions transport are highly demanded for energy storage devices. Layered double hydroxides (LDHs), bearing uniform interlayer galleries and abundant hydroxyl groups covalently bonded within two-dimensional (2D) host layers, make them superb candidates for high-performance membranes. However, related research on LDHs for ions separation is quite rare, especially the deep-going study on ions transport behavior in LDHs. Here, we report a LDHs-based composite membrane with fast and selective ions transport for flow battery application. The hydroxide ions transport through LDHs via vehicular (standard diffusion) & Grotthuss (proton hopping) mechanisms is uncovered. The LDHs-based membrane enables an alkaline zinc-based flow battery to operate at 200 mA cm −2 , along with an energy efficiency of 82.36% for 400 cycles. This study offers an in-depth understanding of ions transport in LDHs and further inspires their applications in other energy-related devices. Membranes with fast and selective ion transport are highly relevant for energy storage devices. Here, the authors report a layered double hydroxide membrane with high ionic selectivity and hydroxide ion conductivity for flow battery applications, and reveal the ions transport mechanism of the membrane.

To study the source and content change of oridonin in the ice ribbons, the contents of oridonin in the ice ribbons and bleeding sap of Isodon rubescens at different times were determined with RP-HPLC. The paraffin sectioning and electron microscopy imaging were performed to study the transport channel of oridonin in the stem. The results showed that there were abundant xylem rays and perfect pit pairs in the secondary xylem of I. rubescens stems. The oridonin content in the ice ribbons of I. rubescens stems was lower than that in the stem of I. rubescens and even decreased over time. The contents of oridonin in the bleeding sap of I. rubescens stems was equal to that in second-day ice ribbons and was lower than that in first-day ice ribbons. The water in the ice ribbons of I. rubescens stems originated from water absorbed by the roots from soil. This water was transported from the roots of I. rubescens to the stem and then transferred through efficient lateral conducting tissues to the surface of the stem. The oridonin in the phloem and cortex of I. rubescens stems dissolves in water originating from the soil and freezes in the form of ice ribbons below 0 °C.

There are 5–15 pairs of leaves on the stem of Isodon rubescens . The I. rubescens leaves at different nodes are far apart because the internodes are long. The photosynthetic rates, light response curves and chlorophyll fluorescence characteristics of I. rubescens leaves at different leaf positions were determined in this study to clarify the differences in photosynthetic capacity distinctions of among these leaves. The results showed that the photosynthetic capacity of I. rubescens leaves on the upper part of the stem was slightly lower than that of the leaves on the middle part of the stem. However, the incompletely unfolded tender leaf on the upper part of the I. rubescens stem possessed considerable photosynthetic capacity. The leaves on the middle part of the I. rubescens stem were the main site of photosynthesis for the plant. The I. rubescens leaves at the lower leaf position exhibited a lower photosynthetic capacity. Pruning during the cultivation and management of I. rubescens could prompt the formation of tender leaves and therefore increase the photosynthetic efficiency of plants.

A simple, rapid, and effective colorimetric assay for the detection of uric acid (UA) has been built, using the MoS2 nanoflakes-catalyzed 3,3′,5,5′-tetramethylbenzidine (TMB)-H2O2 system. In the presence of oxygen and uricase, uric acid was oxidized specifically to produce H2O2. MoS2 nanoflakes synthesized by hydrothermal reaction could catalyze the oxidation of TMB by H2O2, and engendering the colorimetric signal. Finally, the change in the color from colorless to blue was seen with naked eye, indicating the presence or absence of UA. Under the optimized conditions, a linear relationship between the absorbance and UA concentration in the range of 0.5–100 μM (R2 = 0.996) with the limit of detection for 0.3 μM (S/N = 3). The proposed assay was successfully applied to the detection of UA in human serum with the recoveries over 94.54%. Thus, these results suggest that the UA assay–based MoS2-catalyzed TMB-H2O2 has great foreground for fast clinical diagnosis of gout without the need for advanced and costly equipment.

The ultrafast transport of adsorbates in confined spaces is a goal pursued by scientists. However, diffusion will be generally slower in nano-channels, as confined spaces inhibit motion. Here we show that the movement of long-chain molecules increase with a decrease in pore size, indicating that confined spaces promote transport. Inspired by a hyperloop running on a railway, we established a superfast pathway for molecules in zeolites with nano-channels. Rapid diffusion is achieved when the long-chain molecules keep moving linearly, as well as when they run along the center of the channel, while this phenomenon do not exist for short-chain molecules. This hyperloop-like diffusion is unique for long-chain molecules in a confined space and is further verified by diffusion experiments. These results offer special insights into molecule diffusion under confinement, providing a reference for the selection of efficient catalysts with rapid transport in the industrial field. Normally, the diffusion of the object is suppressed in the confined space. Here, by regulating the degrees of freedom of the molecule, authors demonstrate ultrafine diffusion in the sub-nano space.

The diurnal variation of photosynthesis, light response curve and CO 2 response curve in Epimedium brevicornu Maxim leaves were determined with Li-6400 photosynthesis system to evaluate the photosynthesis of E. brevicornu . Fluorescence of chlorophyll in the leaves were determined with PAM-2500 portable chlorophyll fluorescence apparatus in the study. The results showed that the midday depression of photosynthesis was very obvious in the E . brevicornu leaves. The light compensation point of E . brevicornu leaves was about 15 µmol m −2 s −1 . The light saturation point of E. brevicornu leaves was below 800 µmol m −2 s −1 , which was lower than the general sunlight intensity at noon in summer. The CO 2 saturation point of E. brevicornu leaves was much higher than the content of CO 2 in general air. E. brevicornu was a typical shade plant and could survive in very low sunlight. E. brevicornu could not endure strong sunlight and high air temperature. The net photosynthetic rate of E. brevicornu leaves linearly correlated with the content of CO 2 in the leaf chamber when the content was below CO 2 saturation point. E. brevicornu possessed great potential of photosynthesis.

By employing ab initio molecular dynamic simulations, solid-state NMR spectroscopy, and two-dimensional correlation analysis of rapid scan Fourier transform infrared spectroscopy data, a new pathway is proposed for the formation of methyl acetate (MA) via the acylium ion (i.e.,CH 3  − C ≡ O + ) in 12-membered ring (MR) channel of mordenite by an integrated reaction/diffusion kinetics model, and this route is kinetically and thermodynamically more favorable than the traditional viewpoint in 8MR channel. From perspective of the complete catalytic cycle, the separation of these two reaction zones, i.e., the C-C bond coupling in 8MR channel and MA formation in 12MR channel, effectively avoids aggregation of highly active acetyl species or ketene, thereby reducing undesired carbon deposit production. The synergistic effect of different channels appears to account for the high carbonylation activity in mordenite that has thus far not been fully explained, and this paradigm may rationalize the observed catalytic activity of other reactions. The tremendous application of carbonylation reaction requires the elaborate explanation to reaction mechanism. Here the authors propose a charge-separation driven mechanism of methyl acetate formation via acylium ion intermediate in mordenite zeolite by an integrated reaction/diffusion kinetics model during the dimethyl ether carbonylation.

The biomass of Isodon rubescens stems is greater than that of the leaves. The stems possess a considerable surface area, although less than that of the leaves. The photosynthetic rates, light response curves and chlorophyll fluorescence characteristics of the stems were determined in this study to clarify their photosynthetic capacity and photosynthetic potential. The results showed that the I. rubescens stems possessed considerable photosynthetic capacity, although less than that of the leaves. The shape of the light response curve of the I. rubescens stem was different from that of leaf. The light response curve of stems slowly increased during the intermediate growth period. The light saturation point of the stems was significantly greater than that of the leaves. There was clear, strong light suppression in both stems and leaves. However, I. rubescens stems could effectively photosynthesize, and the stem has a high light saturation point and can adapt to intense light.

As a vital component of public space, public open space (POS) is considered crucial for community regeneration. However, most evaluation studies have focused on the geographical attributes of POS, and those assessing renewal holistically in terms of residents’ everyday lives are limited. Drawing on the Ruijin community in Shanghai, this study compared networks of public space layout and residents’ daily behaviours as a function of their structure and individual nodes using the Social Network Analysis method to explore the characteristics and evaluate the effectiveness of renewal. The results showed: (1) the current renewal while increasing recreational opportunities and improving spatial appearance has had a limited effect at the social level. (2) There are differentiations between the two networks. POS plays different roles in the behavioural network, including comprehensive, intermediary, and directional nodes. (3) The core POSs have frequent interactions and strong links with specific types of public facilities than the periphery. Therefore, we suggested that POS renewal should be conducted according to the rule of “core preceding periphery, comprehensive high-efficiency preceding single low-efficiency” and explain the necessity of public participation in the process. These findings shed light on the potential mechanism of the impact of POS on everyday life and rethink the construction management and governance of urban community regeneration in the era of sustainability.