Synthesis of Hydroxylamine via Ketone-Mediated Nitrate Electroreduction.

Hydroxylamine (HA, NH2OH) is a critical feedstock in the production of various chemicals and materials, and its efficient and sustainable synthesis is of great importance. Electroreduction of nitrate on Cu-based catalysts has emerged as a promising approach for green ammonia (NH3) production, but the electrosynthesis of HA remains challenging due to overreduction of HA to NH3. Herein, we report the first work on ketone-mediated HA synthesis using nitrate in water. A metal-organic-framework-derived Cu catalyst was developed to catalyze the reaction. Cyclopentanone (CP) was used to capture HA in situ to form CP oxime (CP-O) with C═N bonds, which is prone to hydrolysis. HA could be released easily after electrolysis, and CP was regenerated. It was demonstrated that CP-O could be formed with an excellent Faradaic efficiency of 47.8%, a corresponding formation rate of 34.9 mg h-1 cm-2, and a remarkable carbon selectivity of >99.9%. The hydrolysis of CP-O to release HA and CP regeneration was also optimized, resulting in 96.1 mmol L-1 of HA stabilized in the solution, which was significantly higher than direct nitrate reduction. Detailed in situ characterizations, control experiments, and theoretical calculations revealed the catalyst surface reconstruction and reaction mechanism, which showed that the coexistence of Cu0 and Cu+ facilitated the protonation and reduction of *NO2 and *NH2OH desorption, leading to the enhancement for HA production.

C─H Activation Enables the Construction of New Bis-Polyaryl Phenylpyridine Ruthenium Complexes: Conjugation and Rigidity Synergistic Effect for Advanced Electrochemiluminescence.

The access to bench-stable organometallic compounds unfolds new chemical space for medicinal and material sciences. In particular, stable organoruthenium compounds with constitutional and stereoisomeric forms for subtle regulation of electrochemiluminescence are intriguing and challenging. Here, coordination of polycyclic aromatic hydrocarbons on (2-phenylpyridine)2(CO)2Ru complex allows access to bis-polyaryl phenylpyridine (BPP) Ruthenium complex through C─H activation strategy and coupling reactions for installation of the functionalities with steric and electronic purposes. The photoluminescence and electrochemiluminescence of BPP Ru complexes are affected by the actual polycyclic aromatic hydrocarbons inherent properties. The anthracene derivatized BPP Ru complex (BPP-Ant) shows the best ECL performance and reveals an enormous ECL quantum efficiency of 1.6-fold higher than the golden standard Ru(bpy)3 2+. The unprecedentedly high efficiency is due to the best compromise between the structural conjugation and molecular rigidity from BPP-Ant providing a providential energy gap that facilitated the feasibility of electron transfer and favored the radiative energy release by experimentally and DFT calculations. Moreover, PL and spooling ECL spectroscopies are used to track and link multiple emission peaks of BPP-Ant at 445, 645, and 845 nm to different emissive species. These discoveries will add a new member to the efficient ECL ruthenium complex family and bring more potentials.

Fast Responsive and High-Strain Electro-Ionic Soft Actuator Based on the 3D-Structure MXene-EGaIn/MXene Bilayer Composite Electrode.

Electro-ionic soft actuators have garnered significant attention owing to their promising applications in flexible electronics, wearable devices, and soft robotics. However, achieving high actuation performance (large bending strain and fast response time) of these soft actuators under low voltage has been challenging due to issues related to ion diffusion and accumulation. In this study, an electro-ionic soft actuator is fabricated using Ti3C2Tx MXene and eutectic gallium-indium (EGaIn) composite material as the bilayer electrode and methylammonium formate/1-ethyl-3-methylimidazolium tetrafluoroborate/poly(vinylidene fluoride) (MAF-EMIMBF4/PVDF) as the ionic liquid-type electrolyte. The research results indicate that the prepared soft actuator exhibits excellent actuation performance with a peak-to-peak displacement of 35 mm and a bending strain of 0.69% (a peak-to-peak strain of 1.38%) under a low voltage (3 V). The electro-ionic soft actuator shows a wide frequency range (0.1-10 Hz), fast response time (0.35 s), and a rise time of 7.5 s. Furthermore, it demonstrates good cyclic durability, with a retention rate of 92.5% of its performance for 10 000 cycles. These excellent performances are attributed to the 3D structure of the Ti3C2Tx-EGaIn/Ti3C2Tx bilayer composite electrode, as well as the characteristics of the low viscosity, high conductivity, small ion volume, and larger volume difference between cations and anions in MAF ionic liquid. The high-performance electro-ionic soft actuator can be used in various fields such as artificial muscles, tactile devices, and soft robots.

Effects of lactic acid bacteria on antioxidant activity in vitro and aroma component of Eucommia ulmoides tea.

Eucommia ulmoides tea is a popular functional health drink in Asian countries, but its unique herbal aroma is difficult for consumers to accept. The effects of four lactic acid bacteria strains (Lactobacillus plantarium, Lactobacillus bulgaricus, Lactobacillus acidophilus and Streptococcus thermophilus) fermentation on the physicochemical property, antioxidant activity in vitro and aroma component of E. ulmoides leaves were studied. Within the four strains, the sample by L. bulgaricus fermentation showed the higher concentrations of chlorogenic acid, geniposidic acid and stronger antioxidant activity in vitro. Moreover, the sample by L. bulgaricus fermentation produced a stronger fruity and floral flavor. These results suggested that L. bulgaricus was the best strain for fermentation E. ulmoides tea. The differences between different strains should be considered when selecting lactic acid bacteria for raw material fermentation of fruits and vegetables.

In situ Generation of Cyclohexanone Drives Electrocatalytic Upgrading of Phenol to Nylon-6 Precursor.

Coupling in situ generated intermediates with other substrates/intermediates is a viable approach for diversifying product outcomes of catalytic reactions involving two or multiple reactants. Cyclohexanone oxime is a key precursor for caprolactam synthesis (the monomer of Nylon-6), yet its current production uses unsustainable carbon sources, noble metal catalysts, and harsh conditions. Herein, we report the first work to synthesize cyclohexanone oxime through electroreduction of phenol and hydroxylamine. The Faradaic efficiency reached 69.1% over Cu catalyst, accompanied by a corresponding cyclohexanone oxime formation rate of 82.0 g h-1 gcat-1. In addition, the conversion of phenol was up to 97.5%. In situ characterizations, control experiments, and theoretical calculations suggested the importance of balanced activation of water, phenol, and hydroxylamine substrates on the optimal metallic Cu catalyst for achieving high-performance cyclohexanone oxime synthesis. Besides, a tandem catalytic route for the upgrading of lignin to caprolactam has been successfully developed through the integration of thermal catalysis, electrocatalysis, and Beckmann rearrangement, which achieved the synthesis of 0.40 g of caprolactam from 4.0 g of lignin raw material.

Improving CO2-to-C2+ Product Electroreduction Efficiency via Atomic Lanthanide Dopant-Induced Tensile-Strained CuOx Catalysts.

Cu is a promising electrocatalyst in CO2 reduction reaction (CO2RR) to high-value C2+ products. However, as important C-C coupling active sites, the Cu+ species is usually unstable under reduction conditions. How atomic dopants affect the performance of Cu-based catalysts is interesting to be studied. Herein, we first calculated the difference between the thermodynamic limiting potentials of CO2RR and the hydrogen evolution reaction, as well as the *CO binding energy over Cu2O doped with different metals, and the results indicated that doping atomic Gd into Cu2O could improve the performance of the catalyst effectively. On the basis of the theoretical study, we designed Gd1/CuOx catalysts. The distinctive electronic structure and large ion radii of Gd not only keep the Cu+ species stable during the reaction but also induce tensile strain in Gd1/CuOx, resulting in excellent performance of the catalysts for electroreduction of CO2 to C2+ products. The Faradic efficiency of C2+ products could reach 81.4% with a C2+ product partial current density of 444.3 mA cm-2 at -0.8 V vs a reversible hydrogen electrode. Detailed experimental and theoretical studies revealed that Gd doping enhanced CO2 activation on the catalyst, stabilized the key intermediate O*CCO, and reduced the energy barrier of the C-C coupling reaction.

Oxophilicity-Controlled CO2 Electroreduction to C2+ Alcohols over Lewis Acid Metal-Doped Cuδ+ Catalysts.

Cu-based electrocatalysts have great potential for facilitating CO2 reduction to produce energy-intensive fuels and chemicals. However, it remains challenging to obtain high product selectivity due to the inevitable strong competition among various pathways. Here, we propose a strategy to regulate the adsorption of oxygen-associated active species on Cu by introducing an oxophilic metal, which can effectively improve the selectivity of C2+ alcohols. Theoretical calculations manifested that doping of Lewis acid metal Al into Cu can affect the C-O bond and Cu-C bond breaking toward the selectively determining intermediate (shared by ethanol and ethylene), thus prioritizing the ethanol pathway. Experimentally, the Al-doped Cu catalyst exhibited an outstanding C2+ Faradaic efficiency (FE) of 84.5% with remarkable stability. In particular, the C2+ alcohol FE could reach 55.2% with a partial current density of 354.2 mA cm-2 and a formation rate of 1066.8 µmol cm-2 h-1. A detailed experimental study revealed that Al doping improved the adsorption strength of active oxygen species on the Cu surface and stabilized the key intermediate *OC2H5, leading to high selectivity toward ethanol. Further investigation showed that this strategy could also be extended to other Lewis acid metals.

Physiological, biochemical and molecular responses associated with drought tolerance in grafted grapevine.

BACKGROUND: Grafting is one of the promising techniques for improving abiotic stress tolerance in horticultural crops, but the underlying regulatory mechanisms of drought on grafted grapevine are largely unexplored. RESULTS: Herein, we investigated the phenotypic, physiologic, biochemical, and drought related genes change of self-rooted 1103P (1103 Paulsen), SM (Shine Muscat) and grafted SM/1103P (SM shoot/1103P root) under drought stress condition. The results indicated that grafted grapevine effectively alleviated drought damage in grape leaves by higher RWC, water potential and free water content. Drought stress led to the alterations of chlorophyll, carotenoid, photosynthetic parameters and chlorophyll fluorescence in grapevine leaves after drought treatment indicated grafted plants improved the photosystem response to drought stress. Moreover, grafted plants under drought stress exhibited higher levels of abscisic acid (ABA), indoleacetic acid (IAA) and soluble protein, but less contents of hydrogen peroxide (H2O2) and malondialdehyde (MDA) both in leaves and roots. Drought stress also increased the activities of antioxidant enzymes (SOD, POD and CAT) and activated the transcript expression of VvCu/ZnSOD, VvPOD4 and VvCAT1) in both leaves and roots. Further expression analysis by real-time PCR indicated that the expression levels of ABA-dependent and ABA-independent related genes could be activated in grafted grape after drought treatment. CONCLUSIONS: Taken together, our findings demonstrated that grafting onto 1103P enhanced tolerance against drought stress in grape by improving water content, photosynthesis and antioxidant defense capacity, which provided a valuable information for understanding the mechanisms of drought tolerance regulated by grafting plants.

Ligands in Lead Halide Perovskite Nanocrystals: From Synthesis to Optoelectronic Applications.

Ligands are indispensable for perovskite nanocrystals (NCs) throughout the whole lifetime, as they not only play key roles in the controllable synthesis of NCs with different sizes and shapes, but also act as capping shell that affects optical properties and electrical coupling of NCs. Establishing a systematic understanding of the relationship between ligands and perovskite NCs is significant to enable many potential applications of NCs. This review mainly focuses on the influence of ligands on perovskite NCs. First of all, the ligands-dominated size and shape control of NCs is discussed. Whereafter, the surface defects of NCs and the bonding between ligands and perovskite NCs are classified, and corresponding post-treatment of surface defects via ligands is also summarized. Furthermore, advances in engineering the ligands towards the high performance of optoelectronic devices based on perovskite NCs, including photodetector, solar cell, light emitting diode (LED), and laser, and finally to potential challenges are also discussed.

Five long-distance dispersals shaped the major intercontinental disjunctions in Tectariaceae s.l. (Polypodiales, Polypodiopsida).

Intercontinental disjunct distributions can arise either from vicariance, from long-distance dispersal, or through extinction of an ancestral population with a broader distribution. Tectariaceae s.l., a clade of ferns in Polypodiales with ca. 300 species mainly distributed in the tropics and subtropics, provide an excellent opportunity to investigate global distribution patterns. Here, we assembled a dataset of eight plastid markers and one nuclear marker of 636 (92% increase of the earlier largest sampling) accessions representing ca. 210 species of all eight genera in Tectariaceae s.l. (Arthropteridaceae, Pteridryaceae, and Tectariaceae s.s.) and 35 species of other families of eupolypods Ⅰ. A new phylogeny is reconstructed to study the biogeography and trait-associated diversification. Our major results include: (1) a distinct lineage of Tectaria sister to the rest of the American Tectaria is identified; (2) Tectariaceae s.l., and the three families: Arthropteridaceae (Arthropteris), Pteridryaceae (Draconopteris, Malaifilix, Polydictyum, Pteridrys), and Tectariaceae s.s. (Hypoderris, Tectaria, and Triplophyllum), might have all originated in late Cretaceous; (3) only five intercontinental dispersals occurred in Pteridryaceae and Tectariaceae s.s. giving rise to their current intercontinental disjunction; (4) we provide the second evidence in ferns that a long-distance dispersal between Malesia and Americas during the Paleocene to Eocene led to the establishment/origin of a new genus (Draconopteris); and (5) diversification rate of each state of leaf dissection is different, and the lowest is in the simple-leaved taxa.

Phylogeny, biogeography, and character evolution of the genus Sophora s.l. (Fabaceae, Papilionoideae).

The papilionoid legume genus Sophora (Fabaceae) exhibits a worldwide distribution, but a phylogenetic framework to understand the evolution of this group is lacking to date. Previous studies have demonstrated that Sophora is not monophyletic and might include Ammodendron, Ammothamnus, and Echinosophora, but the relationships among these four genera (defined as Sophora s.l.) are unclear. Here we used a nuclear DNA dataset (ETS, ITS, SQD1) and a plastid DNA dataset (matK, rbcL, rpl32-trnL, trnL-F) of 654 accession sequences to reconstruct the phylogenetic relationships, estimate the divergence times and ancestral range of Sophora s.l., and infer the evolution of chromosome number and morphological characteristics. Our major aim was to reconstruct phylogenetic relationships to test monophyly and elucidate relationships within the genus. Our results indicated that Ammodendron, Ammothamnus, and Echinosophora are embedded within Sophora s.s. and that nine well-supported clades can be recognized within comprise Sophora s.l. Ancestral character state estimation revealed that the most recent common ancestor of Sophora s.l. was a deciduous shrub that lacks rhizome spines and has unwinged legumes. Divergence times estimation and ancestral area reconstruction showed that Sophora s.l. originated in Central Asia and/or adjacent Southeast China in the early Oligocene (ca. 31 Mya) and dispersed from these regions into East and South Asia's adjacent areas and North America via the Bering land bridge. The analyses also supported a South American origin for S. sect. Edwardsia, which experienced rapid radiation with its major lineages diversifying over a relatively narrow timescale (8 Mya).

Phylogeny, character evolution, and biogeography of the fern genus Bolbitis (Dryopteridaceae).

Bolbitis is a pantropical fern genus of Dryopteridaceae with ca. 80 species mainly in tropical Asia. Earlier studies confirmed the monophyly of Bolbitis when Mickelia is excluded and identified three major clades in Bolbitis. However, earlier studies are based on relatively small sampling and the majority of Asian species are not sampled. In this study, DNA sequences of three plastid markers of 169 accessions representing ca. 68 (85 % of total) species of Bolbitis in nine out of the 10 series recognized by Hennipman (1977), and 54 accessions representing the five remaining bolbitidoid genera are used to infer a global phylogeny with a focus on Asian species. The major results include: (1) Bolbitis is strongly supported as monophyletic; (2) species of Bolbitis are resolved into four major clades and their relationships are: the Malagasy/Mascarene clade is sister to the rest, followed by the African clade which is sister to the American clade + the Asian clade; (3) six well-supported subclades are identified in the most speciose Asian clade; (4) the free-veined Egenolfia is embedded in Bolbitis and is paraphyletic in relation to species with anastomosing venation; (5) three series sensu Hennipman (1977), B. ser. Alienae, B. ser. Egenolfianae, and B. ser. Heteroclitae, are paraphyletic or polyphyletic; (6) evolution of six morphological characters is analyzed and free venation is found to have evolved from anastomosing venation and reversed to free venation in Bolbitis; and (7) biogeographical implications are drawn and it is shown that a single recent dispersal from Asia resulted in continental disjunction of closely related ferns of Bolbitis between Africa and America.

Splitting one species into 22: an unusual tripling of molecular, morphological, and geographical differentiation in the fern family Didymochlaenaceae (Polypodiales).

The pantropical fern genus Didymochlaena (Didymochlaenaceae) has long been considered to contain one species only. Recent studies have resolved this genus/family as either sister to the rest of eupolypods I or as the second branching lineage of eupolypods I, and have shown that this genus is not monospecific, but the exact species diversity is unknown. In this study, a new phylogeny is reconstructed based on an expanded taxon sampling and six molecular markers. Our major results include: (i) Didymochlaena is moderately or weakly supported as sister to the rest of eupolypods I, highlighting the difficulty in resolving the relationships of this important fern lineage in the polypods; (ii) species in Didymochlaena are resolved into a New World clade and an Old World clade, and the latter further into an African clade and an Asian-Pacific clade; (iii) an unusual tripling of molecular, morphological and geographical differentiation in Didymochlaena is detected, suggesting single vicariance or dispersal events in individual regions and no evidence for reversals at all, followed by allopatric speciation at more or less homogeneous rates; (iv) evolution of 18 morphological characters is inferred and two morphological synapomorphies defining the family are recognized-the elliptical sori and fewer than 10 sori per pinnule, the latter never having been suggested before; (v) based on morphological and molecular variation, 22 species in the genus are recognized contrasting with earlier estimates of between one and a few; and (vi) our biogeographical analysis suggests an origin for Didymochlaena in the latest Jurassic-earliest Cretaceous and the initial diversification of the extant lineages in the Miocene-all but one species diverged from their sisters within the last 27 Myr, in most cases associated with allopatric speciation owing to geologic and climatic events, or dispersal.

Self-enhanced peroxidase-like activity in a wide pH range enabled by heterostructured Au/MOF nanozymes for multiple ascorbic acid-related bioenzyme analyses.

Nanozymes, a class of catalytic nanomaterials, have shown great potential to substitute natural enzymes in various applications. Nevertheless, the pursuit of high-efficiency peroxidase-like activity in a wide pH range is one of the major challenges existing in designing nanozymes. A feasible strategy is to construct an artificial active center by using porous materials as stable supporting structures, which can actively modulate biocatalytic activities via their porous atomic structures and more active sites. Herein, a gold nanoparticles/metal-organic framework (MOF) heterostructure was prepared using UiO-66 as a stable support structure (Au NPs/UiO-66), which demonstrates enhanced peroxidase-like activity, ∼8.95 times higher than that of pure Au NPs. Strikingly, Au NPs/UiO-66 exhibits excellent stability (maintains above 80% activity at 40-70 °C and retains 93% activity after 3 months of storage) and sustained high relative activity (above 90%) over a pH range of 5.0-9.0 due to the homogeneous dispersibility of free-ligand Au NPs and the strong chemical interaction between the Au NPs and the UiO-66 host. Moreover, a colorimetric assay of ascorbic acid (AA) and three AA-related biological enzymes was developed based on Au NPs/UiO-66 nanozyme, which has a good linear detection range and excellent anti-interference ability. This work provides important guidance for the expansion of metal NPs/MOF heterostructure nanozymes and their application prospects in the development of biosensors.

Mn2+ and Sb3+ Codoped Cs2ZnCl4 Metal Halide with Excitation-Wavelength-Dependent Emission for Fluorescence Anticounterfeiting.

In recent years, there has been a growing demand for luminescence anticounterfeiting materials that possess the properties of environmentally friendly, single-component, and multimode fluorescence. Among the materials explored, the low dimensional metal halides have gained wide attention because of unique characteristics including low toxicity, simple synthesis, good stability, and so on. Here, we synthesized Mn2+ and Sb3+ codoped Cs2ZnCl4 single crystals by a facile hydrothermal method. Under 365 nm excitation, the codoped compound exhibits dual-band emissions at 530 and 730 nm. However, under 316 nm excitation, the compound only shows one emission band from 500 to 850 nm peaking at 730 nm, while under 460 nm excitation, the emission from 500 to 650 nm with an emission peak at 530 nm can be observed. Based on the study of the photoluminescence mechanism, the green and red emissions originate from the Mn2+ located in the tetrahedron and self-trapped exciton emission of [SbCl4]- clusters, respectively. Due to the zero-dimensional structure of the Cs2ZnCl4 host, there is minimal energy transfer between these dopants. Consequently, the luminous ratios of the two emissions can be independently regulated. Except by tuning the dopant concentrations, the Cs2ZnCl4:Mn2+, Sb3+ demonstrates excitation-wavelength-dependent properties, which could emit more than two colors with the change of excitation wavelength. As a result, multimode anticounterfeiting based on Cs2ZnCl4:Mn2+, Sb3+ crystals has been designed, which aligns with the requirements of environmentally friendly, single-component, and multimode fluorescence properties.

Evaluation of the factors affecting lung function in pediatric patients with asthma.

PURPOSE: This study aimed to analyze the risk factors affecting lung function in children with asthma based on clinical data to advice on clinical treatment and prognosis. METHODS: This study included newly diagnosed patients with asthma admitted to the Respiratory Department of Chengdu Women's and Children's Central Hospital in Sichuan from July 2020 to June 2021. The factors associated with lung function were analyzed using univariate and multivariate linear regression with the forward method, while factors affecting lung ventilation function were analyzed using multivariate logistic regression. RESULTS: Sixty percent of the patients had normal lung function. Age was significantly negatively correlated with forced vital capacity (FVC)/FVCpredicted (B = -1.385, p = 0.001), FEV1/FEV1predicted (B = -2.092, p < 0.001), and FEV1%/FEV1%predicted (B = -0.834, p = 0.001). Body mass index (BMI) for age Z score (B = 1.661, p = 0.045) and cesarean delivery (B = 4.471, p = 0.013) were significantly positively correlated with FVC/FVCpredicted. Birth weight was significantly positively correlated with FEV1/FEV1predicted (B = 4.593, p = 0.027). Multivariate logistic regression analysis revealed that age ≥6 years and cough variant asthma (CVA) were risk factors for abnormal lung function. CONCLUSIONS: Age, BMI for age Z score, mode of delivery, and birth weight were significantly correlated with lung function in children with asthma. Furthermore, children with asthma and normal lung function were more likely to be overlooked. More attention should be given to children with asthma and normal lung function, and CVA.

Connection number based model for coordination development evaluation of regional water resources, social economy and ecological environment complex system.

The development of social economy often requires a large consumption of water resources, and will also discharge a large amount of pollutants to the environment. Currently, the rapid development of regional water resources, social economy and ecological environment (WSE) complex system encounters significant challenges, and the coordination development of WSE complex system becomes important and necessary condition of regional sustainable development. Therefore, to scientifically evaluate the coordination development state of WSE system, based on the establishment of evaluation index system, the connection number and distance coordination model coupling approach for the coordination development evaluation of WSE complex system was proposed in this manuscript. The application results of the proposed method in Anhui Province, China indicate that, during 2011-2020, the coordination level of Anhui province is relatively high, and the coordination grade of most cities are in grade I or II. The coordination development degree of Anhui province presented a distinct improving trend with time, from most cities in grade IV or V in 2011 to most cities in grade II in 2020, from the worst 0.0580 in 2011 to the best 0.9200 in 2020. In terms of space, the coordinated development level of southern Anhui is higher than that of northern Anhui. Meanwhile, the coordination development status of the 16 cities in Anhui province can be divided into three patterns according to its historical variation characteristics, i.e., coordination development mode, ecological environment backward mode, and social and economic backward mode. Compared with the commonly used coordination evaluation method, the method of this paper can solve the problem of homogenization, and its calculation results are more reasonable and practical.

Structure Simulation and Equilibrium Evaluation Analysis of Regional Water Resources, Society, Economy and Ecological Environment Complex System.

Currently, the implementation of water resource spatial equilibrium strategy is a fundamental policy of water resource integrated management in China; it is also a considerable challenge to explore the relationship structure features of water resources, society, economy and ecological environment (WSEE) complex system. For this purpose, firstly, we applied information entropy, ordered degree and connection number coupling method to reveal the membership characteristics between different evaluation indicators and grade criterion. Secondly, the system dynamics approach was introduced to describe the relationship features among different equilibrium subsystems. Finally, the ordered degree, connection number, information entropy and system dynamics integrated model was established to conduct relationship structure simulation and evolution trend evaluation of the WSEE system. The application results in Hefei city, Anhui Province, China, demonstrated that: (1) the variation of overall equilibrium conditions of WSEE system in Hefei city, 2020-2029 was higher compared to that of 2010-2019, though the increasing rate of ordered degree and connection number entropy (ODCNE) became slower after 2019; and (2) the annual ODCNE value from 2020 to 2029 of WSEE system under dry year scenarios increased about 0.0812, which indicated that the construction of Yangtze-Huaihe Diversion (YHD) project could play significant positive role in mitigating the equilibrium situation of WSEE system in Hefei city in the future. On the whole, this study is capable of providing the guidance basis for constructing a theoretical framework of structure simulation and equilibrium evaluation analysis of WSEE complex system.

Boosting Electrocatalytic Nitrate-to-Ammonia via Tuning of N-Intermediate Adsorption on a Zn-Cu Catalyst.

The renewable-energy-powered electroreduction of nitrate (NO3 - ) to ammonia (NH3 ) has garnered significant interest as an eco-friendly and promising substitute for the Haber-Bosch process. However, the sluggish kinetics hinders its application at a large scale. Herein, we first calculated the N-containing species (*NO3 and *NO2 ) binding energy and the free energy of the hydrogen evolution reaction over Cu with different metal dopants, and it was shown that Zn was a promising candidate. Based on the theoretical study, we designed and synthesized Zn-doped Cu nanosheets, and the as-prepared catalysts demonstrated excellent performance in NO3 - -to-NH3 . The maximum Faradaic efficiency (FE) of NH3 could reach 98.4 % with an outstanding yield rate of 5.8 mol g-1 h-1 , which is among the best results up to date. The catalyst also had excellent cycling stability. Meanwhile, it also presented a FE exceeding 90 % across a wide potential range and NO3 - concentration range. Detailed experimental and theoretical studies revealed that the Zn doping could modulate intermediates adsorption strength, enhance NO2 - conversion, change the *NO adsorption configuration to a bridge adsorption, and decrease the energy barrier, leading to the excellent catalytic performance for NO3 - -to-NH3 .

Synergistic Effect Improves the Response of Active Sites to Target Variations for Picomolar Detection of Silver Ions.

Heavy metal ions seriously threaten human health; even a trace of them can damage the renal, nervous, and immune systems irreversibly. Although established nanozyme-based colorimetric assays have been designed for the rapid detection of heavy metal ions, the general contained surface organic ligands of nanocatalysts and low absorptivity of metal ions on solid substrates might result in a weak effect on active sites and prevent the realization of their full detection potential. Here, we developed a nanozyme-based colorimetric sensor (CPM-Pt) made by pyrolysis of peat moss with preabsorbed traces of Pt ions to ultrasensitively detect Ag+. The calcination removes organic components and produces bare nanozymes that expose rich active sites. The strong protective effect from the porous carbon support enables the embedded Pt nanoparticles (Pt NPs) with a partially stable positive charge after pyrolysis (∼28% Pt2+ species). By the d8-d10 metal-metal interactions between Pt2+ (4f145d8) and Ag+ (4d10), the high proportion of Pt2+ species on the surface of Pt NPs can readily capture/absorb Ag+. Subsequently, Ag+ accepts electrons from the support to form Ag atoms, which rapidly cover the peroxidase-like active sites of bare Pt NPs, weakening the activation of H2O2 to realize the response of Ag+. The colorimetric detection limit of Ag+ reached an unprecedented 1.1 pM, and the corresponding naked-eye color recognition is ultrasensitive to extremely low levels (100 pM).