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The behaviour of photoexcited electrons in light-responsive coordination polymers (CPs) significantly determines their performance in fluorescence sensing, smart materials, photoelectric display and photocatalysis, and this behaviour can be skilfully manipulated by optimizing the geometric and electronic structures of the ligand field around the metal ion. To reveal the micro-environmental effect of the ligand field on the bandgap and photoexcited electrons, three semiconductive Cd(II)-based CPs have been achieved through coordination of π-conjugated 2,6-bis(2-pyrazin-2-yl)-4-(4-(tetrazol-5-yl)phenyl)pyridine (HL) and 1,3,5-benzenetricarboxylic acid (H3BTC) with Cd(II) ion. Possessing N3O4 and O6 donors, complex 1 assumed an extended triple-decker sandwich structure with a central {Cd2(BTC)} sheet terminated up and down by planar L− spacers. Two quadrangular {Cd2(L)2} dimers with N4O3 and N4O2 donors were propagated by doubly deprotonated HBTC2− connectors to the cationic (4 4) layer of 2. The reproducible {Cd2(L)2} dimers with only N4O3 donors in 3 were extended by mirror-symmetric HBTC2− linkers to a bent chain. The distinct donor combinations in the local ligand fields of Cd(II) ions dominated the bandgaps and movements of the charge-carriers. Emitting intense steel blue fluorescence, complex 1 served as a highly efficient bilirubin probe with a quenching constant up to 9.48 × 104 M−1 driven by photo-induced electron charge and Förster resonance energy transfer. In contrast, complex 2, with excellent separation efficiency of charge carriers, acted as a photocatalyst to completely degrade methylene blue up to 97% within 90 minutes of UV irradiation. Apparently, slight modifications of the surroundings of the ligand field by a heterodonor strategy achieved a remarkable effect on the photophysical properties of the semiconductive CPs, providing valuable hints for the construction of photosensitive CPs. [ABSTRACT FROM AUTHOR]

In this study, we have found two new species—Stropharia subrugosoannulata and Stropharia microaeruginosa. Phylogenetic analyses, based on the internal transcribed spacer regions (ITS) and the nuclear ribosomal RNA gene (nrLSU), suggest that the two new species are distinct and monophyletic. S. subrugosoannulata is distinguished from other species of the genus Stropharia by the pileus covered with greyish-orange squamules in the centre, stipe light brown and surface covered with white triangular squamules. S. microaeruginosa differs from other species in its pileus bluish-grey when young becoming lighter towards margins, later greyish-turquoise lightens towards the edges and surface radially striate when young, lamellae adnate to subdecurrent, stipe with white squamules at the base, acanthocytes absent. The new record species from Jilin Province, Clitolyophyllum umbilicatum was also confirmed, based on morphological and molecular study. Here, we have given full descriptions of each species, colour images, illustrations and two phylogenetic trees that show the placement and relationship of the two new species and the new record are provided. [ABSTRACT FROM AUTHOR]

Habitat is fundamental for facilitating various life activities in animals, for instance, snakes procure essential energy for survival and reproduction by selecting ambush microhabitats. While there has been extensive research on the selection of microhabitat for feeding in terrestrial and aquatic snakes, little is known about arboreal snakes. In the present study, we analyzed the ambush microhabitat preferences of Viridovipera stejnegeri, a widely distributed Asian pitviper in China, conducted association analysis between snake microhabitat and prey microhabitat and abundance to determine the ro5le of microhabitat selection in feeding. Employing random forest analysis and habitat selection functions, we further constructed a predictive framework for assessing the probability of ambush site selection by V. stejnegeri. Our results revealed that V. stejnegeri exhibited a distinct microhabitat preference for ambush prey. Among the 13 environmental factors assessed, V. stejnegeri showed pronounced preferences towards 12 of these factors, including climatic factors, geographical factors, and vegetation factors. Furthermore, although the preferences of V. stejnegeri overlapped substantially with those of its prey across multiple habitat factors, food abundance shows no significant association with various habitat factors of V. stejnegeri, and does not have significant predictive effect on habitat selection of V. stejnegeri. Therefore, we infer that V. stejnegeri does not preferentially select microhabitats with the highest food abundance, which does not support the hypothesis that "snakes select habitats based on the spatial distribution of prey abundance." By analyzing the characteristics of vegetation, geography, and climate, we conclude that V. stejnegeri tends to choose microhabitats with better ambush conditions to increase attack success rate, thereby achieving the optimal feeding success rate at the microhabitat scale, which is in line with the predictions of optimal foraging theory. This study provides new insights into the predation ecology and habitat selection of snakes. [ABSTRACT FROM AUTHOR]

Non-conjugated luminescent polymers (NCLPs) have the advantages of simple synthesis, optical tunability, and excellent processability. However, the underlying luminous mechanism in NCLPs remains obscure and it is a considerable challenge to obtain NCLPs with ultra-long phosphorescence lifetime and multicolour emission simultaneously. In this article, linear polyurethane derivatives (PUs) with cluster-induced aggregation, multicolour luminescence and ultra-long phosphorescence have been prepared by simply adjusting the reaction temperature and the reaction time. DFT calculations and molecular dynamics simulations provide elaborate microstructural information on the PUs. With the synergistic effect of abundant hydrogen bonding interactions, through-space dative bonds, short interatomic contacts and oxygen clusters various luminous clusters are formed. The energy level splitting caused by clusters with different extents of spatial conjugation endows the NCLPs with multicolour clusteroluminescence, promotes intersystem crossing (ISC), and stabilises the triplet excited state, and finally an ultra-long room temperature phosphorescence (RTP) lifetime of 0.45 s is attained. Experimental encryption/decryption models validate the potential of the PUs in information security. The results have important implications for understanding the intrinsic mechanism of unconventional luminescence in the absence of any traditional conjugative units or heavy atom effects, and they provide a new horizon for the strategic design of multicolour luminescence and ultra-long phosphorescence in NCLPs for a range of practical applications. [ABSTRACT FROM AUTHOR]

In this study, a new cobalt-based metal–organic framework (JLNU-500), [Co2(OH)(PBA)(AIP)]·3DMA·0.75H2O (4-(pyridin-4-yl) benzoic acid (HPBA), 5-aminoisophthalic acid (H2AIP) and N,N-dimethylacetamide (DMA)), was fabricated using a solvothermal method. JLNU-500 has 3D network architecture with 1D nanopore channels. The prepared JLNU-500 can activate peroxymonosulfate (PMS) for Rhodamine B (RhB) dye decolorization. Interestingly, catalyst JLNU-500 exhibited high efficiency for PMS activation, and nearly 100% (above 99.8%) removal of RhB with a high concentration (50.0 mg L−1, 100 mL) was achieved within 6 min. The reaction rate constant of the JLNU-500/PMS system was 1.02 min−1 calculated based on the pseudo-first-order kinetics, which is higher than that of the other reported catalysts. Furthermore, the factors, which could influence PMS activation were also investigated, such as PMS dosage, catalyst dosage, pollutant RhB concentration, reaction temperature and solution pH. More importantly, the radical trapping experiments ferreted out that sulfate (SO4˙−) and hydroxyl (˙OH) radicals were the dominating oxidants in the removal of RhB. Moreover, the possible degradation mechanism was elucidated. This study provides new prospects for fabricating new MOFs that can potentially be employed for high-efficiency catalytic oxidation as heterogeneous catalysts. [ABSTRACT FROM AUTHOR]

Superhydrophobicity and superhydrophilicity are extreme properties of solid surface governed by surface morphology and surface chemistry. Switching between superhydrophobicity and superhydrophilicity can be achieved by applying external stimuli and exchanging counterions due to the change in surface morphology and/or surface chemistry. This review mainly gives a concise overview of switchable wettability of surface. Through applying external stimuli such as light, temperature, pH value, solvent, electric potential and exchanging of counterions, the wettability of surface can switch between superhydrophobicity and superhydrophilicity. The material with asymmetric wettability exhibits some novel abilities such as directional liquid transport. Finally, the advances of surface with switchable wettability are prospected. By controlling the micro-nano structure and chemical composition, the switch between superhydrophobicity and superhydrophilicity can be realized on various surfaces.

Power companies are mainly capital-intensive companies, and the efficiency of working capital management has a profound impact on the sustainability and stability of the development of power companies. This paper uses the DEA-CCR method to measure the working capital management efficiency of listed Chinese power companies from 2014 to 2019, and uses the Tobit regression method to analyze the factors that affect the working capital management efficiency. The results show: (1) The overall efficiency of working capital management of listed Chinese power companies is low, and there is still much room for improvement. (2) Decomposition of comprehensive technical efficiency results in pure technical efficiency and scale efficiency, both of which have an important impact on the overall working capital management efficiency of listed Chinese power companies. (3) Among listed electric power companies, the overall working capital management efficiency of central enterprises is lower than that of non-central enterprises. In response to the above conclusions, this article proposes measures such as reforming the working capital management system, optimizing the profitability of core businesses, and improving supply chain capital management to improve the working capital management efficiency of listed electric power companies.