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Ultrathin titanate nanosheet is one kind of important material for wide applications, but the efficient strategy and lucid mechanism for controllable preparing ultrathin titanate nanosheet with considerable size is still a challenge. Herein, an improved strategy is described for the production of ultrathin titanate nanosheets using macromolecule tetrabutylammonium hydroxide (TBAOH) intercalation. Reaction parameters such as alkali carbonate source, molar ratio of Cs2CO3 and TiO2, calcination temperature are studied systematically. The products are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet–visible absorbance (UV–vis), Fourier-transform infrared (FT-IR), and Raman spectroscopic. The formation mechanism of titanate nanosheet is investigated. The host layer is of lepidocrocite-type in which TiO6 octahedral are combined via edge sharing to produce a two-dimensional sheet of composition Ti2−x/4□x/4O4x- (x ~0.7; □, vacancy), while Cs+ is located interlayer. The elevated calcined temperature can promote the degree of solid-state reaction, enabling the lateral size of the two-dimensional sheet to become larger, therefore the exfoliated nanosheet has a larger considerable size. It has been found that when the calcination temperature is 1100 °C, the alkali carbonate is Cs2CO3, the molar ratio of Cs2CO3 and TiO2 is 1:5.3, ultrathin monolayer titante nanosheet with a considerable size is prepared successfully. Three variable systems of alkali carbonate source, molar ratio of Cs2CO3 and TiO2, calcined temperature are studied systematically and the ultrathin monolayer titante nanosheet with a considerable size is prepared successfully, which is benefit of in-depth theoretical research and application for ultrathin 2D titanate nanosheet in the future.

The development of single-atom catalysts anchored on two-dimensional (2D) conductive matrix with well exposed active sites has great significance in electrocatalytic energy storage yet remains challenging. Inspired by the power of biomolecular self-assembly in making delicate nanostructures, we report a novel template-free folic acid (FA) self-assembly strategy to achieve the facile preparation of ultrathin N-doped carbon nanosheet confining single-metal-atom catalysts (M-N-C SAC, M = Co, Ni, Zn, Fe). The 2D association of FA is developed for the first time via the ribbon-like H bonding pattern and metal-FA coordination in a mixed solvent. A tunable metal loading content of the catalysts is facilely realized through a pH-tuned FA partial dissociation chemistry. As a proof of demonstration, Co-N-C SAC shows an excellent performance for lean electrolyte lithium-sulfur battery. Our findinging suggest a new and potentially scalable route for facile fabrication of M-N-C SACs for broad energy storage applications.

Gas reservoir characterization is one of the frontiers in seismic exploration. Acoustic impedance, one of the most effective seismic attributes, aims to describe the spatial distribution of rock properties. However, using acoustic impedance only is insufficient to describe gas-bearing layers accurately, in the case of rapid lithologic changes and complex geology in the deepwater area. The reflection seismograms indicate an absorption effect when seismic waves propagate through gas-bearing layers. The absorption effect can be used as an additional attribute to help gas reservoir characterization. Therefore, we have developed a new attribute for gas reservoir characterization in this study, which integrates the results of acoustic impedance and absorption coefficient. We estimate the acoustic impedance model by using poststack impedance inversion and then we calculate probability distribution functions. Functions are classified into gas-bearing and nongas layers. We discuss an absorption coefficient and obtain it from the spectrum gradient, in which the gradient is calculated by spectral decomposition using the matching pursuit method. We apply the new attribute to characterize the spatial distribution and thickness of deepwater gas reservoirs in the Pearl River Mouth Basin. Well-log and geologic information indicate that the study area has an enrichment of gas reservoirs. Field data application indicates the explicit distribution of the gas reservoir and in accordance with the well-log information, which indicates that our attribute can improve gas reservoir characterization.

Electrocatalytic seawater splitting has been considered as a transformative technology for industrial-scale hydrogen generation. However, the competition between the oxygen evolution reaction (OER) and chlorine evolution reaction (CER) at the anode with sluggish kinetics is the main bottleneck. Herein, an organic-oxidation-assisted strategy has been demonstrated, in which the thermodynamically favorable methanol selective oxidation reaction (MSOR) is used to suppress the undesired OER/CER using carbon paper supported Pt–Co3O4 electrocatalysts (denoted as Pt–Co3O4/CP), leading to hydrogen and value-added formate generation simultaneously with significantly low energy consumption. In the integrated two-electrode electrolyzer using Pt–Co3O4/CP bifunctional electrocatalysts, the required cell voltage at 10 mA cm−2 is only 0.555 V when adding 2.0 M methanol, which is 1022 mV lower than that in alkaline seawater. The integrated cell also produces hydrogen and formate simultaneously with high faradaic efficiency and considerable durability. The findings in this work represent a new direction for energy-saving production of hydrogen from seawater.

Efficient non-noble metal catalysts are desirable to greatly improve the efficiency of anodic oxygen evolution and cathodic hydrogen evolution reactions. Herein, iron-nickel/carbon nanotube composites are synthesized as efficient bifunctional electrocatalysts for water splitting. The catalyst is homogeneously distributed, while the formation of iron-nickel alloy is confirmed. Because of the synergism of iron and copper and the contribution of carbon nanotubes, the Fe–Ni/CNT electrocatalyst shows excellent oxygen evolution reaction performance with the overpotential of 221 mV at 10 mA cm−2 and maintains stable at 0.48 V for 150 h. It expedites overall water splitting at 10 mA cm−2 with 1.50 V and show excellent stability at 20 mA cm−2 for 65 h, providing great potential for large-scale applications.

Different scales of voids and cavities in karst systems demonstrate considerable potential as exploration targets in the Tarim Basin, northwest China. Numerous diffraction events exist in the seismic data above the karst reservoir in this area because of the strong impedance contrast and irregular shape of voids. The conventional impedance inversion method using migrated data as an input cannot easily estimate the location of voids and the impedance inside the voids. In this case, an alternative approach to impedance inversion that considers the diffractive component of the total wavefield and uses the unmigrated data as an input should be used. The inversion consists of a least-squares minimization of the misfit function between the observed and modeled data. Forward modeling incorporates a combination of reflection and diffraction wavefield components. The adopted method is applied to physical modeling and field data recorded above the karst reservoir. This study’s physical modeling test simulates observed field data and is performed using a high-resolution and high-fidelity 3D modeling system. Inversion results obtained by the proposed and conventional methods are compared. Physical modeling and a field data application show that the adopted impedance inversion method improves the karst location estimation and the acoustic impedance within the voids.

The inefficiency of water splitting is mainly due to the sluggish anodic water oxidation reaction. Replacing water oxidation with thermodynamically more favorable selective methanol oxidation reaction and developing robust bifunctional electrocatalysts are of great significance. Herein, a hierarchical heteronanostructure with Ni–Co layered double hydroxide (LDH) ultrathin nanosheets coated on cobalt phosphide nanosheets arrays (CoxP@NiCo-LDH) are fabricated and used for co-electrolysis of methanol/water to co-produce value-added formate and hydrogen with saving energy. Benefiting from the fast charge transfer introduced by phosphide nanoarrays, the synergy in nanosheets catalysts with hetero-interface, CoxP@NiCo-LDH/Ni foam (NF) exhibits superior electrocatalytic performance (10 mA cm−2 @ 1.24 V and −0.10 V for methanol selective oxidation and hydrogen evolution reaction, respectively). Furthermore, CoxP@NiCo-LDH/NF-based symmetric two-electrode electrolyzer drives a current density of 10 mA cm−2 with a low cell voltage of only 1.43 V and the Faradaic efficiency towards the generation of formate and H2 are close to 100% in the tested range of current density (from 40 to 200 mA cm−2). This work highlights the positive effect of hetero-interaction in the design of more efficient eletrocatalysts and might guide the way towards facile upgrading of alcohols and energy-saving electrolytic H2 co-generation.

Pseudocapacitors with high power density, long-term durability, as well as reliable safety, play a key role in energy conversion and storage. Designing electrode materials combing the features of high specific capacitance, excellent rate performance, and outstanding mechanical stability is still a challenge. Herein, a facile partial sulfurization strategy has been developed to modulate the electronic structure and crystalline texture of cobalt hydroxide nanosheets (denoted as Co(OH)2) at room temperature. The resultant cobalt hydroxysulfide nanosheet (denoted as CoSOH) electrode with abundant low-valence cobalt species and amorphous structure, exhibits a high specific capacitance of 2110 F g−1 at 1 A g−1 with an excellent capability retention rate of 92.1% at 10 A g−1, which is much larger than that of Co(OH)2 precursor (916 F g−1 at 1 A g−1 and 80% retention at 10 A g−1). Furthermore, the fabricated asymmetric supercapacitor device con structed with CoSOH and active carbon displays a considerable high energy density of 44.9 W h kg−1 at a power density of 400 W kg−1, and exceptional stability after 8000 cycles.

To boost hydrogen production from water splitting, the electrochemical oxidation of biomass-derived molecules to produce valuable chemicals is regarded as a promising approach to replace the kinetically sluggish oxygen evolution reaction. Herein, copper sulfide nanowire@NiCo-layered double hydroxide (LDH) nanosheet core–shell nanoarrays are fabricated as efficient bifunctional electrocatalysts for 5-hydroxymethylfurfural (HMF) oxidation and water reduction to simultaneously produce value-added 2,5-furandicarboxylic acid (FDCA) and hydrogen fuel with less energy consumption. Benefiting from the fast charge transfer induced by the CuxS core, the Co/Ni interaction in the LDH nanosheet layer and the open nanostructure, the optimized catalysts exhibit superior electrocatalytic activity (record-high 87 mA cm−2 @ 1.3 V vs. RHE for HMF oxidation; η = 107 mV @ 10 mA cm−2 for HER) and durability; the faradaic efficiency towards FDCA and H2 is close to unity. The bifunctional two-electrode electrolyzer only requires a low voltage of 1.34 V to co-generate H2 and FDCA at 10 mA cm−2. This work highlights the significance of tuning the redox properties of transition metals and constructing nanoarray electrocatalysts towards more efficient energy utilization.

Seismic diffraction waveform energy contains important information about small-scale subsurface elements, and it is complementary to specular reflection information about subsurface properties. Diffraction imaging has been used for fault, pinchout, and fracture detection. Very little research, however, has been carried out taking diffraction into account in the impedance inversion. Usually, in the standard inversion scheme, the input is the migrated data and the assumption is taken that the diffraction energy is optimally focused. This assumption is true only for a perfectly known velocity model and accurate true amplitude migration algorithm, which are rare in practice. We have developed a new approach for impedance inversion, which takes into account diffractive components of the total wavefield and uses the unmigrated input data. Forward modeling, designed for impedance inversion, includes the classical specular reflection plus asymptotic diffraction modeling schemes. The output model is composed of impedance perturbation and the low-frequency model. The impedance perturbation is estimated using the Bayesian approach and remapped to the migrated domain by the kinematic ray tracing. Our method is demonstrated using synthetic and field data in comparison with the standard inversion. Results indicate that inversion with taking into account diffraction can improve the acoustic impedance prediction in the vicinity of local reflector discontinuities.

Developing an efficient approach of transforming biomass waste to functional carbon-based electrode materials applied in supercapacitor offers an important and high value-added practical application due to the abundance and considerable low price of biomass wastes. Herein, a hierarchical carbon functionalized with electrochemical-active oxygen-containing groups was fabricated by microwave treatment from the biomass waste of camellia oleifera. The obtained mesoporous carbon (MAC) owns nanosheet morphology, rich mesoporosity, large surface area (1726 m2/g) and very high oxygenic functionalities (16.2 wt%) with pseudocapacitive activity. Prepared electrode of supercapacitor and tested in 2.0 M H2SO4, the MAC exhibits an obvious pseudocapacitive activity and achieved a superior supercapacitive performance to that of directly activated carbon (DAC-800) including high specific capacitance (367 F/g vs. 298 F/g) and better rate performance (66% vs. 44%). The symmetrical supercapacitor based on MAC shows a high capacity of 275 F/g, large energy density of 9.55 Wh/kg (at power density of 478 W/kg) and excellent cycling stability with 99% capacitance retention after 10000 continuous charge-discharge, endowing the obtained MAC a promising functional material for electrochemical energy storage.

Sweet chestnut (Castanea sativa) is an endemic species of genus Castanea in Europe, which is widespread in the southern part of continental Europe. The complete genome sequence of chloroplast was determined through Illumina NovaSeq platform. Totally the genome of chloroplast was 160,938 bp in length, GC rich (36.8%), comprising a pair of 25,726 bp inverted repeat sequences, separated by a 90,519 bp large and 18,967 bp small single-copy regions. There were 129 genes, including 37 transfer RNA genes, 8 ribosomal RNA genes, and 84 protein-coding genes. The phylogenetic tree analysis showed that C. sativa exhibited the closest relationship with Castanea henryi.

An oxide catalyst plays an important role in environmental catalysis. Metal chlorides are widely used as precursors in the preparation of oxide catalysts. However, residual chlorine usually influen...

Mesoporous bismuth nanosheets are prepared through electrochemical transformation of (100)-facet exposed BiOI. Theoretical modeling and calculations are used to simulate the in situ morphological transformation of BiOI into Bi. Mesoporous Bi nanosheets show superior electrochemical CO2 reduction performance. A faradaic efficiency of 95.9 % at -0.77 VRHE for the conversion of CO2 into formic acid, is achieved for the mesoporous Bi nanosheet catalyst compared with 93.8 % at -0.87 VRHE for the smooth Bi nanosheets. Tafel analysis and DFT calculations indicate that the electrochemical CO2 reduction on mesoporous Bi nanosheets is kinetically faster with a higher resistance to H2 generation than that on smooth Bi(001) nanosheets. The CO2 -to-HCOOH pathway is preferred through formation of an *OCHO intermediate on the (012) and (001) planes of Bi. The mesoporous structure induces a more accessible interaction with CO2 , which makes a predominant contribution to the enhanced performance compared with the subsequent CO2 activation on different facets of Bi.

The increasing need for clean and sustainable energy inspires researchers to explore low-cost nonprecious metal electrocatalysts for advanced energy storage and conversion. Herein, we develop a rea...

There is a growing body of evidence suggesting an association between air pollution exposure and tuberculosis (TB) incidence, but no meta-analysis has assembled all evidence so far. This review and meta-analysis aimed to derive a more reliable estimation on the association between air pollution and TB incidence. PubMed, Embase and Web of Science electronic databases were systemically searched for eligible literature. The PECO framework was used to form the eligibility criteria. Effect estimates and 95% confidence intervals (CIs) published in the included studies were pooled quantitatively. Seventeen articles met the inclusion criteria. The pooled estimates showed that long-term exposure to particulate matter with an aerodynamic diameter ≤10 μm (PM10) was associated with increased incidence of TB (per 10 μg/m3 increase in concentrations of PM10: risk ratios (RR) = 1.058, 95% CI: 1.021–1.095). Besides, long-term exposure to sulfur dioxide (SO2) and nitrogen dioxide (NO2) were significantly associated with TB incidence (per 1 ppb increase, SO2: RR = 1.016, 95% CI: 1.001–1.031; NO2: 1.010, 95% CI: 1.002–1.017). We did not find a significant association of PM2.5, ozone (O3) or carbon monoxide (CO) with TB risk, regardless of long-term or short-term exposure. However, in view of the 2016 ASA Statement and the biological plausibility of PM2.5 damaging host immunity, the association between PM2.5 and TB risk remains to be further established. This meta-analysis shows that long-term exposure to PM10, SO2 or NO2 is associated with increased odds of TB, and the specific biological mechanisms warrant further research.

Two-dimensional (2D) materials have attracted great attention due to their unique physical and chemical properties derived from the dimensionality effect and modulation in their band structure. Herein, an important industrial catalytic material, gamma alumina (γ-Al2O3) with well-defined two-dimensional nanosheet structure was fabricated by a designed crown ether induced assembly approach. The obtained γ-Al2O3 nanosheets with a thickness of ∼4 nm possess high surface area (351 m2/g) and 16% pentacoordinate Al3+ sites which are the main catalytic active sites for ethanol dehydration to ethylene, compared to almost no pentacoordinate Al3+ sites for the commercial γ-Al2O3 nanoparticles. Furtherly, systematical investigation reveals that the crown ether plays the key role in the assembly of nanosheet structure. As a catalyst for ethanol dehydration to ethylene, the obtained alumina nanosheets with easily-accessible surface and more active sites, exhibit a superior catalytic performance to the commercial alumina with a much higher yield at large space velocity.

The effective microwave absorption materials could contribute to alleviating the electromagnetic wave pollution. However, conventional microwave absorption materials usually suffer from insufficient absorption intensity and the narrow effective absorption bandwidth. Herein, BiFeO3/BaFe7(MnTi)2.5O19 composites are proposed to address these issues through offering synergetic electromagnetic properties and proper electromagnetic properties. BiFeO3 combined with BaFe7(MnTi)2.5O19 exhibits dielectric multiple relaxation behaviors, strong ferromagnetic resonance and electromagnetic matching, ensuring increased multi-band microwave absorption. Accordingly, the minimum reflection loss (RL) of the composite with volume ratio of 1.5:1 reaches − 48 dB, and the bandwidth less than − 10 dB covers multi-frequencies at C, X and Ku band. These results suggest that BiFeO3/BaFe7(MnTi)2.5O19 composite could be a promising microwave absorption material in imaging, healthcare, information safety and military fields.

Nitrogen doped carbon nanocage with graphitic shell (NGCS) was fabricated through in-situ solid reaction between calcium acetate and dicyandiamide in an inert atmosphere followed by acid etching. The role played by the calcium acetate (Ca(Ac)2) and dicyandiamide (DCD) during the synthesis process is one-stone-two-birds. Calcium acetate plays multiple functions: template agent, graphitization catalyst, and carbon source. Dicyandiamide can be considered as the nitrogen sources and the chemical reaction agent that can be reacted with calcium acetate to form it into CaCN2. The NGCS obtained at 800 °C has a specific surface area of 420 m2/g and nitrogen content of 8.87 at%. The excellent electrochemical performance can be attributed to the combination effects of porous structure, nitrogen doping and graphitized nanocage shell of NGCS electrode. The hollow structure serves as the reservoir for fast electrolyte ion supplement. Nitrogen groups not only improve the wettability of interfaces between carbon surface and electrolyte, but also generate extra pseudocapacitance through redox reaction. The graphitic carbon nanocage shell can enhance the conductivity and facilitates the fast charge transfer. At a current density of 0.5 A/g, the specific capacitance of the NGCS-800 electrode is 215 F/g. Furthermore, the NGCS-800 electrode exhibits excellent rate capability (80% capacitance retention at 10 A/g) and outstanding cycling stability (96.89% capacitance retention after 5000 cycles). These intriguing results demonstrate that nitrogen doped carbon with graphitic shell will be highly promising as electrode materials for supercapacitors and other energy storage and conversation applications.

Developing earth-abundant, highly active, and durable electrocatalysts for the oxygen evolution reaction (OER) is very important for many renewable energy conversion processes. Herein, we report a novel OER electrocatalyst of NiCo layered double hydroxide@NiCo-hydroxysulfide (NiCo-LDH@HOS) nanosheet arrays, which are prepared by a rapid room-temperature sulfurization of the surface of NiCo-LDH nanosheets grown on Ni foam. The surface sulfurization exerts important influences/changes on the structure, composition, surface properties and chemistry of NiCo-LDH. After surface sulfurization, the resulted NiCo-hydroxysulfide layer armor improved electrical conductivity and chemical resistance to alkaline electrolyte, delivers a stable current density of 10.0 mA cm–2 at a low overpotential of 293 mV in 0.1 M KOH solution, maintaining high stability during a 62 h test. The achieved enhanced oxygen evolution activity and improved durability are superior to those of NiCo-LDH nanosheets and benchmark commercial RuO2...

In this work, a series of Pt nanocrystallines (Pt NCs) supported on TiO2 substrate with controlled thickness of carbon layers (C-Pt/TiO2) were synthesized. Well-dispersed Pt NCs were facilely synthesized at room temperature by a photo-reduction process in lytropic liquid crystal (LCs). Surface tuning of the carbon layers on Pt/TiO2 catalysts was achieved by varying the calcination atmospheres (in argon, air, and oxygen) and characterized by XPS and HRTEM. The influence of the coated carbon layers on the catalytic activity of catalysts is investigated by CO oxidation reaction which presented the following ranks: C-Pt/TiO2-O2 > C-Pt/TiO2-Air > C-Pt/TiO2-Ar. It is found that the carbon layer coating can stabilize the Pt NCs and enable them anti-sintering at high temperature. This finding provides new insight into understanding the C-Pt/TiO2 ternary system for tuning their catalytic performance.

Heteroatom doping is a very important approach to improve the performances of carbon-based electrode materials applied in the energy storage and conversion field. Herein, a strategy based on the design of faradaic redox active sites has been developed to synthesize nitrogen and oxygen co-doped carbon foam with a hierarchical porous structure. By a facile two-step method of incipient impregnation and carbonization, the quinone-amine polymer (PAQ) precursor can be in situ polymerized and carbonized on the surface of a nanosized MgO template to obtain carbon foam after removal of MgO with acetic acid. The obtained carbon foam possesses a high content of heteroatoms (total 12.26 at%) as well as faradaic active sites including nitrogen- and oxygen-containing functional groups, which not only enhance the wettability of the electrode material surface to electrolyte but also impart high pseudo-capacitance to the carbon-based skeleton. In addition, the hierarchical micro–meso–macro porous structure provides a large specific surface area (1215 m2 g−1) and a mediated pathway for electrolyte ion diffusion. Serving as a symmetric supercapacitor electrode material in aqueous electrolyte, the co-doped carbon foam yields excellent performance, delivering a high specific capacitance of 321 F g−1 at 1 A g−1, a superior energy density of 15.91 W h kg−1 at a power density of 0.4 kW kg−1, and excellent long-term stability, retaining 98% of its initial capacitance after 15 000 cycles at 5 A g−1.

Earth-abundant spinel ZnCo2O4 is considered as promising electrode materials in the fields of energy storage (e.g. supercapacitor) and conversion (e.g. electrocatalytic water oxidation), but it is still limited by the insufficient material utilization efficiency and poor conductivity. Herein, the two-dimensional ZnCo2O4 nanosheets with abundant oxygen vacancies (OV-ZnCo2O4 nanosheets) have been constructed by facile hydrothermal approach and NaBH4 reduction treatment. The experimental and theoretical calculation results reveal that the as-prepared materials possess enhanced electrical conductivity, modulated electronic structure, increased active sites, and optimal adsorption energies for intermediates. As a supercapacitor electrode, the OV-ZnCo2O4 nanosheets deliver inspiring specific capacitance of 2110.6F g−1 at 1 A g−1. Furthermore, the asymmetric supercapacitor (ASC) assembled by OV-ZnCo2O4 nanosheets//active carbon (AC) exhibits a high energy density of 34.6 Wh kg−1 at a power density of 160 W kg−1. As an electrocatalyst for oxygen evolution reaction (OER), the OV-ZnCo2O4 nanosheets only need remarkably low overpotential of 324 mV to achieve a current density of 10 mA cm−2 in 0.1 M KOH. This work provides an effective strategy for construction of multifunctional electrochemical energy materials.

The growth of a Ni(OH)2 coating on conductive carbon substrates is an efficient way to address issues related to their poor conductivity in electrochemical capacitor applications. However, the direct growth of nickel hydroxide coatings on a carbon substrate is challenging, because the surfaces of these systems are not compatible and a preoxidation treatment of the conductive carbon substrate is usually required. Herein, we present a facile preoxidation-free approach to fabricate a uniform Ni(OH)2 coating on carbon nanosheets (CNs) by an ion-exchange reaction to achieve the in situ transformation of a MgO/C composite to a Ni(OH)2/C one. The obtained Ni(OH)2/CNs hybrids possess nanosheet morphology, a large surface area (278 m2/g), and homogeneous elemental distributions. When employed as supercapacitors in a three-electrode configuration, the Ni(OH)2/CNs hybrid achieves a large capacitance of 2,218 F/g at a current density of 1.0 A/g. Moreover, asymmetric supercapacitors fabricated with the Ni(OH)2/CNs hybrid exhibit superior supercapacitive performances, with a large capacity of 198 F/g, and high energy density of 56.7 Wh/kg at a power density of 4.0 kW/kg. They show excellent cycling stability with 93% capacity retention after 10,000 cycles, making the Ni(OH)2/CNs hybrid a promising candidate for practical applications in supercapacitor devices.

A set of identical Co3O4 nanosheets with different oxygen vacancy amounts are rationally designed by varied reduction treatments and comparison of their properties. Remarkably, the oxygen-vacancy-rich Co3O4 nanosheets (OVR-Co3O4 NSs) exhibit excellent electrochemical performance for their potential use as a promising candidate for the next generation of supercapacitors.

Electrolytic overall water splitting is a promising approach to produce H2 , but its efficiency is severely limited by the sluggish kinetics of the oxygen evolution reaction (OER) and the low activity of current electrocatalysts. To solve these problems, in addition to the development of efficient precious-metal catalysts, an effective strategy is proposed to replace the OER by the selective methanol oxidation reaction. Ni-Co hydroxide [Nix Co1-x (OH)2 ] nanoarrays were obtained through a facile hydrothermal treatment as the bifunctional electrocatalysts for the co-electrolysis of methanol/water to produce H2 and value-added formate simultaneously. The electrocatalyst could catalyze selective methanol oxidation (≈1.32 V) with a significantly lower energy consumption (≈0.2 V less) than OER. Importantly, methanol was transformed exclusively to value-added formate with a high Faradaic efficiency (selectivity) close to 100 %. Specifically, a cell voltage of only approximately 1.5 V was required to generate a current density of 10 mA cm-2 . Furthermore, the Ni0.33 Co0.67 (OH)2 /Ni foam nanoneedle arrays presented an outstanding stability for overall co-electrolysis.

Fracturing fluids are important media for hydraulic fracturing. Typically, the fluids are gelled using a polymeric gelling agent. Technological improvements over the years have focused primarily on improving the rheological performance, thermal stability, and the clean-up of crosslinked gels. In this study, novel supramolecular assembly of a low-damage fracturing fluid combining an ionic polymer gel (hydroxypropyl trimethylammonium chloride guar-cationic guar) and a bola surfactant fluid (bola carboxylate polypropylene glycol) is carried out and it is reported to have improved properties and special characteristics due to the synergistic effects of the dual systems, which are different from those of polymer gels and surfactant fluids. The viscosity of the fracturing fluid shows a sudden increase upon an increase in temperature and excellent self-assembly recovery after shearing. The fracturing fluid exhibits pH-responsive viscosity changes and low permeability impairment, due to the formation of a network structure and supramolecular microspheres at different pH values.

Air pollution is an important risk factor for autoimmune diseases, but its association with the recurrence of rheumatoid arthritis (RA) remains unclear so far. This study aimed to investigate the short-term association between traffic-related air pollutants and hospital readmissions for RA in Hefei, China. Data on daily hospital readmissions for RA and traffic-related air pollutants, including particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2), and carbon monoxide (CO), from 2014 to 2018 were retrieved. A time-series approach using generalized linear regression model was employed. The analysis was further stratified by sex, age and season. A total of 1153 readmissions for RA were reported during the study period. A significant association between high-concentration PM2.5 (90th percentile) and RA readmissions was observed on lag1 (relative risk (RR) = 1.09, 95% confidence interval (CI): 1.01–1.19) and lasted until lag3 (RR = 1.06, 95%CI: 1.01–1.12). From lag2 to lag5, high-concentration NO2 (90th percentile) was associated with increased risk of RA readmissions, with the highest RR observed at lag 4 (1.11, 95%CI: 1.05–1.17). Stratified analyses indicated that females and the elderly appeared to be more vulnerable to high-concentration PM2.5 and NO2 exposure. High-concentration PM2.5 and NO2 in cold seasons were consistently significantly associated with increased risk of RA readmissions. Exposure to high-concentration PM2.5 and NO2 was associated with increased risk of RA readmissions. Protective measures against the exposure to high-concentration PM2.5 and NO2 should be taken to reduce the recurrence risk in RA patients, especially in females, the elderly and during cold seasons.

A felsic intrusion in the Guaguazi Cu mining district in the northern Lanping–Simao terrane, Eastern Tibetan Plateau was revealed through drill holes and is composed of highly fractionated leucogranites. In this paper, we report zircon U–Pb ages and whole-rock compositions to constrain the petrogenesis and geodynamic setting of this intrusion. Zircon grains separated from two leucogranite samples have identical U–Pb ages of 123.9 ± 2.0 Ma and 123.6 ± 1.9 Ma, indicating that the crystallization age of the intrusion is Early Cretaceous (ca. 124 Ma). Leucogranites from the intrusion have SiO2 contents from 74.3 to 77.6 wt% with differentiation index values of 96.3–97.6, indicative of highly fractionated nature. They are weakly peraluminous (A/CNK = 1.01–1.10) and have light REE enrichment ((La/Yb)N = 5.4–8.5) and negative Eu anomalies (Eu/Eu* = 0.26–0.45). The primitive-mantle-normalized spider diagram indicates strong enrichment in large-ion lithophile elements (Rb, Th, U, K, and Pb) relative to high-field-strength elements (Nb, Ta, P, and Ti). The high initial 87Sr/86Sr ratios (0.7070–0.7094) and negative eNd(t) values (−8.18 to −7.20) and TDM2 ages of 1.58–1.51 Ga of the rocks, suggest that their source was predominantly Mesoproterozoic lower continental crust with insignificant mantle contribution. High initial 207Pb/204Pb (15.74–15.75) and 206Pb/204Pb (18.51–18.63) ratios further confirm their crustal source and highly evolved nature. Considering the petrogenetic similarity of Early Cretaceous granitoids in the Guaguazi area and the Gaoligong tectonic belt, we propose that the eastern Bangong–Nujiang Tethyan Ocean was closed at least no later than the Early Cretaceous, and that the Guaguazi granitic intrusion formed in a crustal thickening setting in response to the Lhasa–Qiangtang collision.

The Bengge gold deposit is one of a small number of deposits in the Zhongdian-Muli region, which is part of the southern segment of the Yidun Terrane in the eastern Tibetan Plateau. The deposit is hosted in a Late Triassic alkaline igneous complex comprising mainly biotite–pyroxene syenite and quartz syenite, emplaced into Triassic slate. These syenites show phyllic alteration with mineral association of quartz–sericite–pyrite–carbonate. The main gold mineralization occurs in fault zones as gold–sulfide–quartz veins, in altered syenite as telluride in veinlets, and as fissure-filling gold in disseminated pyrite. Four stages of veins are recognized: sheeted K-feldspar–quartz–magnetite veins (dikes) (stage I), quartz–carbonate–K-feldspar veins with sericite–quartz–pyrite alteration haloes (stage II), polymetallic sulfide–telluride–sericite–quartz veins with pervasive phyllic alteration (stage III), and quartz–carbonate–stibnite veins (stage Ⅳ). The stage II and III veins are closely related to gold mineralization. 40Ar/39Ar dating of hydrothermal sericites from the phyllic alteration zone, which are intergrown with gold-bearing pyrite and telluride, yielded an age of ~126 Ma, indicating the mineralization event occurred in the Cretaceous extensional setting. Raman spectroscopy and microthermometry study for fluid inclusions in quartz from stage II revealed heterogeneous trapping of low-salinity (0.14–6.63 wt% NaCl equivalent) and mesothermal (270–300 °C) CO2–H2O–NaCl ore-forming hydrothermal fluids. The calculated fluid-trapping pressures range mainly from 750 to 850 bar. δ18O values of quartz from the gold mineralization stage (stage II) vary between 15.21‰ and 19.35‰. The δ18O values for waters in equilibrium with quartz vary from 6.96‰ to 10.73‰, which are consistent with values for magmatic waters. We propose that the auriferous fluids were derived from an underlying intrusion during the Cretaceous. The geological characteristics, low salinity, and mesothermal CO2–H2O–NaCl fluids, and the magmatic source of the ore-forming fluids, all support the hypothesis that the Bengge deposit is an intrusion-related gold deposit.

The fast growing applications of ZnO nanoparticles (NPs) in food sector and other fields enhance the exposure possibility of human beings to ZnO NPs including via oral administration route. Although the oral toxicity of ZnO NPs has been studied, most of the research was performed on the normal animal models. Therefore, the understanding of the biological consequence of ZnO NPs on the population with diseases, especially gastrointestinal disease, is extremely limited. In this study, a mice model of inflammatory bowel disease (IBD) induced by indomethacin has been developed to comprehensively investigated the bioeffects of ZnO NPs on the specific population. The effect of the intestinal inflammation/injury on the distribution and toxicity of orally administrated ZnO NPs (nZnO, 20 nm × 100 nm and mZnO, ∼200 nm) in mice were analyzed. The results showed that there was a difference in the distribution of Zn and the essential trace elements (Fe and Cu) between the IBD mice and the normal mice. We also observed an obvious size effect. Higher hepatic Zn was detected in the IBD mice post-exposure to ZnO NPs, especially bigger ZnO NPs. In addition, the histopathological examination of main organs and biological parameters analysis showed that ZnO NPs caused slight toxicity to the liver and kidneys in the IBD mice. Our findings highlight the importance of the health status of animals on the bioeffects of nanomaterials.

In order to better understand and elucidate the structural stability of perovskite materials, the lattice parameters and tolerance factors of three crystal structures of perovskite materials are ca...

The interfacial properties of aramid fibres (AFs) affect their mechanical behaviours. In this work, polyamide acid (PAA) was grafted onto the surface of aramid fibres (AF@PAA) to reinforce epoxy resin (EP E44) by improving the interfacial properties. The AF@PAA contained many active groups and improved the roughness of aramid fibres on the surface, which improved the interfacial performance and mechanical properties of AF-reinforced E44 composites. FTIR and XPS showed the introduction of C–O and –COO–, which confirmed the existence of chemical reactions among groups between the aramid fibres and polyamide acid. A micro-droplet test proved that the benzene ring of the AF could be oxidized under high temperature, and the oxygen-containing groups generated during the oxidation process were important for the grafting process of polyamide acid. The interfacial shear strength (IFSS) increased by 40.7% after treatment with 5 wt% polyamide acid. This study provides a feasible method for interfacial modification in AF-reinforced epoxy resin composites and may be applicable to rubber composite systems.