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C4F7N [2,3,3,3-tetrafluoro-2-(trifluoromethyl)propanenitrile]/CO2 gas mixtures are being developed as an eco-friendly electrical insulator to replace SF6, the most potent greenhouse industrial gaseous dielectric. However, recent studies have reported complicated and often conflicting decomposition pathways for C4F7N/CO2 gas mixtures, which has raised concerns. In this work, the decomposition characteristics of C4F7N/CO2 gas mixtures were studied comprehensively by both designed computations and experiments. Computations were performed starting from fundamental propositions of C4F7N/CO2 decompositions, which were further experimentally verified by pyrolysis, long-term thermal aging with/without catalytic materials (industrial-grade molecular sieves 4A), and electrical decomposition by spark discharge. The results of both computations and experiments suggest that in an ideal thermal decomposition, C4F7N is likely to decompose into C2F6 and small fluoronitriles first at high temperatures. The generation of C3F6 and C2N2 from C4F7N thermal decomposition at lower temperatures appears because of the catalytic effect of incompatible materials, for example, the industrial-grade molecular sieves 4A that we tested. The electron impact dissociation of C4F7N plays an important role in C4F7N electrical decomposition, leading to additional formation of distinctive small molecules of CF4 and C2N2 of low concentrations. It was pointed out based on a real arcing test in a load disconnector that the decomposition of C4F7N gas mixtures in real applications will be at a much moderate and manageable rate than what was obtained from the highly accelerated laboratory tests presented in this work. The signatures of decomposition products extracted in this study provide invaluable guidance for developing decomposition-based diagnosis and fixation of decomposition byproducts toward SF6-free power grids. [ABSTRACT FROM AUTHOR]

CO binding energy has been employed as a descriptor in the catalyst design for the electrochemical CO2 reduction reactions (CO2RR). The reliability of the descriptor has yet been experimentally verified due to the lack of suitable methods to determine CO binding energies. In this work, we determined the standard CO adsorption enthalpies (ΔHCO∘ ${\Delta {H}_{CO}^{^\circ{}}}$) of undoped and doped oxide‐derived Cu (OD−Cu) samples, and for the first time established the correlation of ΔHCO∘ ${\Delta {H}_{CO}^{^\circ{}}}$ with the Faradaic efficiencies (FE) for C2+ products. A clear volcano shaped dependence of the FE for C2+ products on ΔHCO∘ ${\Delta {H}_{CO}^{^\circ{}}}$ is observed on OD−Cu catalysts prepared with the same hydrothermal durations, however, the trend becomes less clear when all catalysts investigated are taken into account. The relative abundance of Cu sites active for the CO2‐to‐CO conversion and the further reduction of CO is identified as another key descriptor. [ABSTRACT FROM AUTHOR]

CO binding energy has been employed as a descriptor in the catalyst design for the electrochemical CO2 reduction reactions (CO2RR). The reliability of the descriptor has yet been experimentally verified due to the lack of suitable methods to determine CO binding energies. In this work, we determined the standard CO adsorption enthalpies (ΔHCO∘ ${\Delta {H}_{CO}^{^\circ{}}}$) of undoped and doped oxide‐derived Cu (OD−Cu) samples, and for the first time established the correlation of ΔHCO∘ ${\Delta {H}_{CO}^{^\circ{}}}$ with the Faradaic efficiencies (FE) for C2+ products. A clear volcano shaped dependence of the FE for C2+ products on ΔHCO∘ ${\Delta {H}_{CO}^{^\circ{}}}$ is observed on OD−Cu catalysts prepared with the same hydrothermal durations, however, the trend becomes less clear when all catalysts investigated are taken into account. The relative abundance of Cu sites active for the CO2‐to‐CO conversion and the further reduction of CO is identified as another key descriptor. [ABSTRACT FROM AUTHOR]

A hypersonic electromagnetic railgun projectile undergoes severe aero-heating with an increase in altitude. The purpose of this study was to investigate the characteristics of the shock layer flow field as well as the thermal environment of the blunt body wall of a hypersonic electromagnetic railgun projectile at different launching angles. The two-temperature model considers the thermal nonequilibrium effect and is introduced into the Navier–Stokes (N-S) equation, and it is solved using the finite volume method (FVM). The reliability of the calculation model in terms of thermal properties and composition production was verified against a blunted-cone-cylinder–flare (HB-2) test case. The surface temperature of the hypersonic blunt projectile was simulated using a radiation balance wall boundary. The thermal characteristics at the emission angles α = 60° and α = 45° were checked within an altitude range of 0–70 km, including the nonequilibrium effect, reaction heat release, aerodynamic heat flux, and wall temperature. The results show that the translational rotational temperature is higher than the vibrational electronic temperature, and the thermal nonequilibrium effect increases with an increase in altitude. Comparing the two launching angles, the nonequilibrium degree and reaction heat release at α = 60° were higher than those at α = 45°. The rates of exothermic reaction decreased with an increase in altitude. The heat flux along the wall of the generatrix decreased sharply from the stagnation point. With an increase in altitude, the heat flux dropped sharply from 7 MW/m2 at H = 0 km to approximately 2 MW/m2 at H = 70 km. The wall temperature distribution was similar to the heat flux distribution; however, the surface temperature decreased less rapidly than the heat flux. [ABSTRACT FROM AUTHOR]

X‐ray Laue diffraction is an important method for characterizing the local crystallographic orientation and elastic strain in polycrystalline materials. Existing analysis methods are designed mainly to index a single or a few Laue diffraction pattern(s) recorded in a detector image. In this work, a novel method called dictionary–branch–bound (DBB) is presented to determine the crystallographic orientations of multiple crystals simultaneously illuminated by a parallel X‐ray incident beam, using only the spot positions in a detector image. DBB is validated for simulated X‐ray Laue diffraction data. In the simulation, up to 100 crystals with random crystallographic orientations are simultaneously illuminated. Fake spots are randomly added to the detector image to test the robustness of DBB. Additionally, spots are randomly removed to test the resilience of DBB against true spots that are undetected due to background noise and/or spot overlap. Poisson noise is also added to test the sensitivity of DBB to less accurate positions of detected spots. In all cases except the most challenging one, a perfect indexing with a mean angular error below 0.08° is obtained. To demonstrate the potential of DBB further, it is applied to synchrotron microdiffraction data. Finally, guidelines for using DBB in experimental data are provided. [ABSTRACT FROM AUTHOR]

We demonstrate the construction of an aggregation-induced electrochemiluminescent (AIECL) sensor for glutathione (GSH) assay by integrating an aminal-linked covalent organic framework (A-COF) with manganese dioxide (MnO2) nanosheets. The AIECL of the A-COF is quenched by the MnO2 nanosheets via electrochemiluminescent resonance energy transfer (ERET) from the excited A-COF to MnO2. The presence of GSH can reduce the MnO2 nanosheets into Mn2+, restoring the AIECL emission of the A-COF. This AIECL sensor has the characteristics of fast response, high sensitivity, and good selectivity toward GSH, and it can accurately measure GSH in human serum. [ABSTRACT FROM AUTHOR]

The composite structure ZSM-5/HMS was synthesized, and modified with zinc species by three methods. The effects of Si/Al ratio of ZSM-5, zinc contents in ZSM-5/HMS, and modification methods on the catalytic performance were investigated. The prepared catalysts were conducted to synthesize iso-octanoic acid under atmospheric pressure, molecular oxygen (O2) as oxidant, and solvent-free conditions. The preparation methods for introducing Zn had a significant influence on the textural properties, zinc species state, acid site distribution of composite materials, and catalytic performance, which was confirmed by the XRD, FT-IR, UV–Vis and NH3-TPD analyses. Both the composite support and loaded zinc had a significant contribution to the catalytic performance, and Zn species could enhance a higher oxygen exchange rate between oxygen gas phase and support. The superior activity could be attributed to the synergistic effect between Zn–Al oxide solid solution, which increased the surface acidity and iso-octanol adsorption capability of the catalysts. The catalyst Zn(400)-3%ZH(52)-D exhibited the highest conversion and remarkable selectivity of around 49.2% and 58.9%, respectively. [ABSTRACT FROM AUTHOR]

Catalytic conversion of CO2 to valuable formate provides a pathway to carbon neutrality. Indium (In), as a promising catalyst, exhibits high selectivity toward formate due to its suitable bonding ability of *OCHO intermediates. However, it still suffers from the CO2 activation and the protonation steps, leading to low activity and productivity. Here, an oxygen‐pinned stabilization AgIn single‐atom alloy (Op‐Ag1In) is presented for efficiently converting CO2 into formate (≈92.03% Faradaic efficiency) with a partial current density of 13 mA cm−2 at −0.95 V vs RHE by using standard H‐type reactor. The Op‐Ag1In electrocatalyst is more effective in converting CO2 to formate because the activated In sites of Op‐Ag1In catalyst regulate CO2 activation and protonation step of CO2RR and formation of sufficient amounts of *OCHO, which are confirmed by in situ spectroscopic and theoretical calculations. The continuous production of formate is showcased at 70 mA cm–2 for 24 h by utilizing a flow cell and Op‐Ag1In. [ABSTRACT FROM AUTHOR]

• Highly selective oxidation of ethylbenzene to acetophenone by O 3 process in a continuous bubbling reactor was proposed. • The structure type of organic solvents has great influence on the ozone mass transfer process. • The indirect oxidation of ozone predominates the reaction course of the ozone oxidation of ethylbenzene. • Possible mechanism of adonization for the synthesis of acetophenone was deduced. Acetophenone is essential to chemical synthesis. Hence, completely using coal tar resources via liquid-phase oxidization to obtain acetophenone is crucial. This study demonstrates a novel, efficient, and environment-friendly technique for converting ethylbenzene to acetophenone based on ozone oxidation and continuous bubbling. Analysis of the mass transfer characteristics of the continuously bubbling ozone in various polar organic solvents showed that alcohol solvents had a higher equilibrium concentration than ethyl acetate and acetone. Equilibrium ozone concentrations were identical in solvents such as chlorinated methane. The solubility of ozone in different solvents may be affected by hydrogen bonding or dipole–dipole interactions between ozone and the solvent molecules. Ethyl acetate was found to be the best solvent after the ozone oxidation conditions of ethylbenzene were refined. The highest amount of acetophenone produced was 74%, and the reaction duration was 120 min; and the corresponding molar ratio of ozone to ethylbenzene was 1.6. Finally, the oxidation of ethylbenzene using ozone was proposed. Hydrogen peroxide accelerated this process, while ethanol slowed it down. The hydroxyl, alkyl, and superoxide free radicals in the reaction system were confirmed via electron paramagnetic resonance studies. Results showed that the key chemical process is indirect ozone oxidation. [ABSTRACT FROM AUTHOR]

The predominance of tricyclic terpanes over hopanes was observed for the first time in the lacustrine rock extracts of the Upper Yanchang Formation collected from Well CYX in the Qingcheng area, Ordos Basin, China. Specifically, hopanes are dominant terpanes in the Chang 7-2 member, while tricyclic terpanes ranging from C 19 to C 39 predominate over hopanes in the Chang 7–3 and Upper Chang 8-1 member. The distributions of terpanes, steranes, as well as n -alkanes vary significantly in these thermally mature rock extracts, however, are closely correlated in each sample. Generally, rock extracts comprising more abundant tricyclic terpanes and their lower molecular weight homologues are characterized by having lower Pr/ n -C 17 ratios and by containing more abundant low molecular weight n- alkanes (n -C 21-) and short-chain C 21-22 steranes. Furthermore, among the Chang 7–2 and Chang 7-3 samples, black shales contain more abundant low molecular weight tricyclic terpanes and n -alkanes (n -C 21-), and short-chain C 21-22 steranes when compared with siltstones and mudstones, which comprise more abundant hopanes, diasteranes and regular C 27-29 steranes. The similar geochemical characteristics could also be found in other rock extracts that have variable abundances of tricyclic terpanes and hopanes, especially in the East Berlin Formation (Hartford Basin, Connecticut, U.S.A), which suggests that the causes for the variable distributions of terpanes, steranes and n -alkanes in these strata are similar. On the one hand, it is determined by the proportion of aquatic versus terrigenous source input and depositional environment. The predominance of tricyclic terpanes over hopanes and short-chain C 21-22 steranes over regular C 27-29 steranes in the Chang 7-3 member, especially in black shales, could be resulted from algal bloom and possibly associated microbial metabolic process in stable or stratified water column, which may be triggered by plentiful nutrients provided by runoff, volcanic or hydrothermal events. On the other hand, high hydrocarbon-generation intensity and petroleum expulsion efficiency for source rocks, especially for black shales, may be another significant driving force for the enrichment of tricyclic terpanes. In such cases, significant oils have been generated and expelled, an early or faster rate of generation/expulsion of hopanes relative to tricyclic terpanes may occurred, which is evidenced by the extended hopanes are depleted in all the studied rock extracts. Furthermore, to our knowledge, the predominance of tricyclic terpanes over hopanes has not been observed in source rocks of the Yanchang Formation in other regions of the Ordos Basin. The observation of the enhanced presence of tricyclic terpanes in the current study may suggest that the hydrocarbon-generating intensity and petroleum expulsion efficiency of source rocks in the Qingcheng area are higher than that of other regions in the basin. Thus, the Qingcheng area has tremendous potential for petroleum resources and is an important area for future exploration. • The predominance of tricyclic terpanes over hopanes in the Chang 7-3 member was firstly reported. • Factors involved in the abnormal abundance of tricyclic terpanes are analyzed. • Algal bloom and strong expulsion of petroleum are responsible for the enhanced presence of tricyclic terpanes. • The relationship between abundant tricyclic terpanes and petroleum exploration potential is discussed. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • P-doped α-Fe2O3 nanorods on Ti foil as PEC electrode. • Phosphorous doping led to a shift of the band structure toward more positive potentials. • The optimized electrode achieved a photocurrent of 2.5 mA/cm2 at 100 mW/cm2 illumination. Abstract The realization of an efficient photocatalytic water splitting in the absence of sacrificial agent is an important step to achieve the sustainable production of hydrogen using solar energy. Heterostructure-based photocatalysts are used to mitigate charge recombination, thus leading to the improved photoactivity. In a traditional electrochemical system, it works similarly as the heterostructure of z-scheme type which transports the photoinduced electrons to the cathode. Herein, by using a photo-electrochemical process, the production of oxygen and hydrogen was achieved with improved photocatalytic faradaic efficiency. The oxygen evolution process (OER) was improved upon modifying the hematite with phosphorous. The phosphorous doping led to a shift of the band structure toward more positive potentials, resulting in higher OER rates. The optimized electrode achieved a plateau photocurrent of 2.5 mA/cm2 at 100 mW/cm2 illumination. [ABSTRACT FROM AUTHOR]

Surface charge accumulation on the insulator surface and the resulting flashover voltage reduction are considered the primary factors to hinder the large-scale use of HVDC system, especially the gas-insulated system. In this study, Buckminster-fullerene C60 of different loadings is introduced into epoxy resin for the purpose of restricting the mobility of charge carriers within the material and thus suppressing the charge accumulation on the insulator surface under dc voltage. Experimental results have shown that with the addition of tiny amount of fullerene C60 into epoxy, the conductivity of the composites decreases significantly with the loading and reaches its minimum around 100∼200 ppm, which can be as low as 20% that of neat epoxy. By using the Kelvin-probe method and an advanced inversion algorithm, the surface charge distribution on the fullerene-filled epoxy resin insulators with different filler loadings are obtained. It is observed that the addition of 200 ppm fullerene C60 into epoxy resin can effectively suppress the charge accumulation on the insulator surface. The interfacial polarization model is adopted to interpret the mechanism of surface charge accumulation, which shows that reducing the bulk conductivity of the insulator can effectively suppress the surface charging. This paper provides a potential solution for engineering epoxy based insulators used for the dc power system. [ABSTRACT FROM AUTHOR]

Combining high-efficient photocatalysts and well-designed photocatalytic reactors is a promising approach to realize the practical photocatalytic degradation of the volatile organic chemicals (VOCs). In this work, the Pd-Ag/AgBr/TiO 2 hierarchical nanostructure was synthesized via a hydrothermal approach followed by the photo-deposition, ion-exchange, and the photo-reduction processes. The bimetallic Pd-Ag co-catalyst on AgBr/TiO 2 composites presented enhanced photocatalytic activity in the photo-degradation of propylene, which was varied with Pd content. The high photocatalytic activity of the hybrid photocatalyst is derived from the high visible-light photocatalytic activity of AgBr and the improved charge separation of the Pd-Ag/AgBr/TiO 2 hierarchical nanostructure. Finally, a self-container hydrothermal method was proposed and prepared the Pd-Ag enhanced AgBr/TiO 2 hierarchical nanostructured photocatalytic hybrid capillary tubes. A well-designed continuous photocatalytic reactor was integrated by fixing the glass capillary tubes onto a pair of circled glass tubes with a Xe arc lamp in the center of the device. The reactor showed a high degradation efficiency of gaseous propylene over a large range of flow rates. Therefore, it possesses a high potential for the practical application to deal with the VOCs. [ABSTRACT FROM AUTHOR]

Five crude oil samples from five wells and 33 oil-containing sandstone reservoir rock samples from six wells of Chang 7 sub-unit were systematically studied to determine hydrocarbons in these oil reservoirs whether are the mixtures of oil components derived from different source rocks or from the same source rock during oil filling process over geological times. Sequential extraction was applied to the oil-containing reservoir rocks to deserve the free and adsorbed oils. The distribution of alkanes, hopanes and steranes and the correlation diagram of Pr/n-C17 versus Ph/n-C18 show that these oil components and crude oils have similar parent materials. And on this basis we compared the thermal maturity of the crude oils, the free oils and adsorbed oils and found that the thermal maturity of these oils is different. The cross plot of C29αα-20S/(20S+20R) versus C29ββ/(αα+ ββ) and the correlation diagram of Pr/n-C17 versus Ph/n-C18 both show that the crude oils have highest thermal maturity, followed by the free oils and then the adsorbed oils. The ratios of ∑C21−/∑C22+ for the crude oils and free oils are greater than the adsorbed oils, indicating the crude oils and free oils have suffered more thermal stress and extensive cracking than that of the adsorbed oils. These geochemical data reveal that hydrocarbons in these oil reservoirs and crude oils were derived from the same source rock with different thermal maturity over geological times. [ABSTRACT FROM AUTHOR]

Charge accumulation on a solid dielectric surface is one of the critical concerns for the design and optimization of the insulation system in a high-voltage power equipment, since it will lead to the overstress of electrical insulation. Therefore, it is important to obtain the charge density distribution on a solid dielectric surface with high accuracy. The acquisition of surface charge for insulators requires multipoint potential measurements to establish the inverse calculation for the determination of an unknown charge distribution. Up to now, extensive studies have been conducted on this subject; nevertheless, the methods are either too complicated and time consuming, or only applicable for specific arrangements, or with poor accuracy. In this paper, the problem is divided into two categories, i.e., shift-variant system and shift-invariant system, and the basic principle of an improved inversion algorithm is interpreted to solve the problem. The 2-D Fourier transform and Wiener filter techniques are employed in the algorithm for shift-invariant system thus the relationship between potential and charge density can be processed in spatial frequency domain, which tremendously simplifies the conventional procedure. The accuracy and resolution of the algorithm are discussed in detail with the aid of numerical examples. In the end, experiments are conducted and the effectiveness of the algorithm is verified. [ABSTRACT FROM AUTHOR]

[Display omitted] • 1. Spin-polarized Ni-Fe-Mo alloys were prepared by a magnetic field-assisted method. • 2. Ni-Fe-Mo alloys with enduring spin polarization can realize higher OER activity. • 3. Providing a promising strategy to prepare efficient ferromagnetic alloy catalysts. The oxygen evolution reaction (OER) constrains the efficiency of water splitting. The catalytic activity of electrocatalysts is mostly determined by the electronic structure, which is expressed as the electron transfer property and the reactant adsorption–desorption capacity. Ferromagnetic electrocatalysts exhibit promising applications in OER. However, an external magnetic field is indispensable for the electron spin polarization of ferromagnetic materials. Here, Ni-Fe-Mo ternary alloy nanowire electrocatalysts were prepared via a magnetic field-assisted self-assembly method in an aqueous-solution system at a mild temperature (65 °C). These Ni-Fe-Mo ternary alloy electrodes feature a spin polarization-dependent OER catalytic performance, which is attributed to ferromagnetic regulation. Ni 0.8 Fe 0.15 Mo 0.05 possesses the maximum ferromagnetism compared to other electrodes (Ni 0.8 Mo 0.2 and Ni 0.8 Fe 0.2) and improved substantially OER activity. The regulated OER activity is assigned to the favorable adsorption of oxygen-containing intermediates (OH*) due to Ni-Fe-Mo composition-dependent, and the accelerated kinetics of OER with enduring spin polarization. The Ni-Fe-Mo ternary alloy nanowires with higher magnetic properties contribute to in situ spin polarization at the surface. This magnetic field-assisted synthesis approach provides a new strategy to realize electrodes with enduring spin polarized. [ABSTRACT FROM AUTHOR]

The common covalent organic frameworks (COFs) cannot achieve high luminescence signal because they are usually connected by imine bonds and rotationally labile imine linkages with the tendency of nonradiative relaxation-mediated self-quenching. Herein, we demonstrate the construction of an aminal-linked COF-based electrochemiluminescent sensor for enantioselective sensing phenylalanine. The aminal-linked COF is constructed via the condensation of emission monomers tetraphenylethylene (TPE) derivative (4′,4″,4′,4′-(1,2-ethenediylidene)tetrakis [1,1′-biphenyl]-4-carboxaldehyde (ETBC) and piperazine. The obtained aminal-linked COF generates a higher ECL signal than the individual components (i.e. , ETBC and piperazine), single pore imine-linked COFs (SP-COF), and dual-pore imine-linked COFs (DP-COF). Notably, the ECL signal generated by the aminal-linked COF with higher crystallinity exhibits 4.5-fold enhancement compared with that generated by amorphous-conjugated microporous polymer (CMP), suggesting that crystalline framework can function as an efficient ECL emitter. Moreover, the aminal-linked COF can be employed for the construction of a novel ECL sensor for selective discrimination of enantiomer L -phenylalanine (L -Phe) from D -phenylalanine (D -Phe), providing a new avenue for chiral recognition. • We construct an aminal-linked covalent organic frameworks (COF)-based electrochemiluminescent sensor. • This ECL sensor can selectively discriminate enantiomer L -phenylalanine (L -Phe) from D -phenylalanine (D -Phe). • The crystalline framework can function as an efficient ECL emitter. • This research provides a new avenue for chiral recognition. [ABSTRACT FROM AUTHOR]

Nickel-based materials have been used in electrochemical water splitting and as a co-catalyst to effectively improve photocatalytic activity. However, the mechanism of the catalytic effect on hydrogen evolution of NiO and Ni(OH)2 needs further investigation because of the high risk in self-reduction with photo-induced electrons. In this work, the self-reduction of Ni2+ was confirmed during the photocatalytic H2 evolution in the CdS/Ni(OH)2 hybrid materials. Meanwhile, in situ formed metallic Ni plays an important role in the increase in the catalytic activity. Fortunately, only a few photo-induced electrons participate in the reduction of Ni2+ in CdS/Ni(OH)2 hybrid materials. The existence of metallic Ni would prevent more Ni2+ from self-reduction. The synergistic effect of Ni(OH)2 and metallic Ni contributes to the improvement of H2 evolution of CdS nanorods. [ABSTRACT FROM AUTHOR]

Providing a driving force is an effective approach to boost the separation of photo-induced charge carriers. Photoelectrode application is the most accepted route. However, it is difficult to realize the high-efficiency photocatalytic activity of granular photocatalysts in suspension by applying the electric field. In this work, on the basis of the Lorentz force-driven improved separation of photo-induced charge carriers in TiO 2 nanobelts, further enhancement of the charge transfer was achieved through constructing a heterostructure of reduced graphene oxide (rGO)/TiO 2 nanobelts (NBs) in a magnetic field. The photocatalytic efficiency of the rGO/TiO 2 NB heterostructure improved by 34% compared with pure TiO 2 NBs under the same magnetic field conditions. This new strategy combined the Lorentz force generated in a magnetic field and the built-in electric field of rGO-TiO 2 NBs to improve photo-induced charge carrier separation and transfer. Furthermore, a wireless microelectric potential was generated in rGO based on the electromagnetic induction effect, which additionally improved the charge transfer in rGO. This work provides a new idea to improve the photocatalytic activity of granular photocatalysts. ga1 • Combining Lorentz force and build-in electric potential to boost charge separation and transfer for powder photocatalysts. • The photocatalytic efficiency of rGO/TiO 2 nanobelts heterostructure in magnetic field can be improved by 107%. • Provide a new idea to boost photocatalytic activity based on external magnetic field and heterostructure. [ABSTRACT FROM AUTHOR]

The Chang 7 member of the Upper Triassic Yanchang Formation in the Ordos Basin is considered to hold the main source rocks for conventional and unconventional oil and gas. The lamination or lithology alteration in vertical and lateral directions, even over a short distance, is a common feature in lacustrine source rocks. The differences in the geochemical characteristics of black shales, dark mudstones and interbedded sandstones have been scarcely reported, and their influences on the petroleum generation potential and shale oil potential are not clear. To this end, 22 core samples were collected from the Lower and Middle Chang 7 (C7-3 and C7-2) members of the Triassic from well CYX in the Qingcheng area. By conducting a series of geochemical analyses including TOC, Rock-Eval pyrolysis yields, bitumen extraction and quantification, and the separation and quantification of saturates, aromatics, resins and asphaltenes, along with biomarker analyses, several results were found. Firstly, the C7-3 and C7-2 source rocks are thermally mature and have entered into the stage of hydrocarbon generation. The C7-3 and C7-2 source rocks have a good to very good hydrocarbon generation potential especially the C7-3 black shales. Secondly, terrigenous source input is more abundant in C7-2, whereas the source input of phytoplankton, algae or microbial lipids is more abundant in C7-3. Moreover, a high TOC content basically corresponds to low wax indexes, terrigenous/aquatic ratios (TARs), and Pr/nC17 and Ph/nC18 ratios and high C27/C29 regular sterane ratios, which suggests that the source input of phytoplankton, algae or microbial lipids is favorable for OM accumulation. Third, analyses of the molecular composition of saturated fractions in shales and interbedded sandstones and the production index demonstrate the migration of petroleum from organic-rich source rocks to their organic-lean counterparts. The C7-2 dark mudstones could be considered as a potential "sweet spot" since their oil saturation index (OSI) was the highest among all the studied samples and they are more enriched in light aliphatic fractions. [ABSTRACT FROM AUTHOR]

High‐entropy alloy (HEA) nanoparticles are emerging catalytic materials and are particularly attractive for multi‐step reactions due to their diverse active sites and multielement tunability. However, their design and optimization often involve lengthy efforts due to the vast multielement space and unidentified active sites. Herein, surface decoration of HEA nanoparticles to drastically improve the overall activity, stability, and reduce cost is reported. A two‐step process is employed to first synthesize non‐noble HEA (FeCoNiSn) nanoparticles and then are surface alloyed with Pd (main active site), denoted as NHEA@NHEA‐Pd. As a demonstration in the ethanol oxidation reaction, a high mass activity of 7.34 A mg−1Pd and superior stability (>91.8% retention after 2000 cycles) in NHEA@NHEA‐Pd are achieved, substantially outperforming traditional HEA, binary M@M‐Pd (M = Sn, Fe, Co, Ni), and commercial Pd/C. In situ spectroscopy reveals that NHEA@NHEA‐Pd can catalytically produce and oxidize CO at <0.5 V, which is >200 mV lower than Sn@Sn‐Pd, suggesting enhanced activity in NHEA@NHEA‐Pd owing to Pd's unique high‐entropy coordination environment. This work provides a novel design of HEA catalysts by combining surface decoration (exposing more active sites) and high‐entropy coordination (enhancing intrinsic activity and structural stability) to boost catalysts' activity and durability. [ABSTRACT FROM AUTHOR]

• Photocatalysis of CdS/MoS 2 /Mo was improved by 89% in magnetic field. • In situ micro-potential drives photo-induced charge separation in suspension. • Hybrid nanostructure combines photocatalyst, co-catalyst and micro-potential. Building a persistently active potential in photocatalyst is always important but difficult for the high-performance photocatalysis. Based on the idea that electromagnetic induction effect can derive an in-situ micro-potential on a micro-conductor, a nanostructured hybrid CdS/MoS 2 /Mo photocatalyst is designed and synthesized by a one-step hydrothermal process. By replacing the commercial magnetic stirrer with the magnetic field strengthened one, the H 2 evolution efficiency of the CdS/MoS 2 /Mo hybrid microstructures is improved by 89% illuminated at 100 mW·cm−2 Xe lamp illumination. The in situ micro-potential in the metallic Mo sheet which is derived from the electromagnetic induction during the relative motion in the magnetic field should play the key role in the enhancement of the photocatalysis. This type of hybrid nanostructure can combine with the photocatalyst, the co-catalyst, and the carrier separation effect of the micro-potential, which can extend the application of the external field in the enhancement of photocatalytic performance, especially for magnetic field application with low extra energy consumption. [ABSTRACT FROM AUTHOR]

• Highly selective oxidation of styrene to benzaldehyde by O 3 process in a rotating packed bed (RPB) was proposed. • RPB-O 3 exhibited higher oxidation property for the synthesis of benzaldehyde. • Effects on the yield of benzaldehyde were optimized with response surface methodology (RSM). • Possible mechanism of ozonization for the synthesis of benzaldehyde was deduced. In this study, the highly efficient procedure for the synthesis of benzaldehyde by ozonolysis of styrene in a rotating packed bed (RPB) reactor has been developed. Ozonolysis in RPB reactor (RPB-ozone) yielded significantly more benzaldehyde compared to the stirred tank reactor (STR) (97 vs. 65 %) in 15 min. Response surface methodology (RSM) was applied to optimize the simultaneous influence of experimental parameters on the yield of benzaldehyde. The relative influence of parameters on the yield of benzaldehyde decreased in the following order: O 3 concentration > high gravity factor = the amount of H 2 O. The significant variable-variable interactions were observed between O 3 concentration and high gravity factor, as well as O 3 concentration and the amount of H 2 O. The optimized reaction conditions using RSM were: 127.27 mg/L of O 3 in the gas phase, high gravity factor of 38.9 and 24.88 mL of H 2 O added, which yielded 97.6 % of benzaldehyde. This was very close to the theoretical value (98.2 %), indicating that RSM analysis was able to predict the yield of benzaldehyde obtained by the ozonization of styrene and provide the optimum experimental conditions. Along with this, the reaction mechanism for the ozonolysis of styrene to benzaldehyde was proposed. [ABSTRACT FROM AUTHOR]

• Degradation of formaldehyde using the MgO/O 3 /H 2 O 2 system was proposed in a rotating packed bed. • Compared with bubbling reactor, formaldehyde removal rate increased by 37.6 % in a rotating packed bed. • The possible pathways of formaldehyde degradation process were proposed. The magnesium oxide (MgO) / ozone (O 3) / hydrogen peroxide (H 2 O 2) system was proposed in this study for oxidative degradation of formaldehyde in wastewater in a rotating packed bed (RPB), and the effects of initial pH, high gravity factor β , MgO dosage, O 3 concentration and H 2 O 2 concentration on the formaldehyde removal rate were investigated. The results showed that at an initial pH of 9, a high gravity factor of 40, a MgO powder dosage of 4 g/L, a H 2 O 2 concentration of 5 g/L, a O 3 dosage of 65 mg/L, a liquid flow of 90 L/h and a gas flow rate of 100 L/h, a 99.93 % and 93.98 % removal rate could be achieved for formaldehyde (2200 mg/L) and chemical oxygen demand (COD) after 60 min, respectively, and the final formaldehyde concentration was 1.45 mg/L, which met the Grade 2 standard set in the Chinese National Standards for Integrated Wastewater (GB 8978-1996). The degradation rates of formaldehyde and COD by RPB-MgO/O 3 /H 2 O 2 , bubbling reactor (BR)-MgO/O 3 /H 2 O 2 , RPB-O 3 /H 2 O 2 and RPB-MgO/O 3 were also compared in the study. The results showed that RPB-MgO/O 3 /H 2 O 2 allowed for more efficient degradation of formaldehyde in wastewater. Possible degradation mechanisms of formaldehyde in wastewater were proposed based on ion chromatography. [ABSTRACT FROM AUTHOR]

Developing novel heterogeneous photo-Fenton catalysts with high efficiency and stability, driven by visible-light rather ultraviolet light at neutral pH has been a major challenge for degradation of organic pollutants. In this work, we successfully synthesized a metalloporphyrin-based porous organic polymer (FePPOP-1) by the Sonogashira cross-coupling reaction. UV–vis absorption spectra showed FePPOP-1 exhibits a significant coverage of the natural solar irradiance spectrum. As a result, the prepared FePPOP-1 has a significantly enhanced photocatalytic activity for the visible-light-driven degradation of methylene blue. By using only 4 mg of FePPOP-1 as a catalyst, it was found that 50 mL of organic wastewater containing 70 ppm MB could be totally degraded in 80 min even at neutral pH. The effects of the initial MB, H 2 O 2 concentrations, pH value and common ions on MB degradation were studied in detail. Both the catalytic mechanism of FePPOP-1 and the degradation route of MB were also proposed. Image 1 • Metalloporphyrin-based POP as a photo-Fenton catalyst was applied in the MB degradation for the first time. • Under visible light irradiation, MB can be effectively photodegraded by FePPOP-1 even at neutral pH. • Both a plausible degradation pathway of MB and a possible photocatalytic mechanism of FePPOP-1 are proposed. [ABSTRACT FROM AUTHOR]

Suppressing the recombination of photogenerated charges is one of the most important routes for enhancing the catalytic performance of semiconductor photocatalysts. In addition to the built‐in field produced by semiconductor heterostructures and the photo‐electrocatalysis realized by applying an external electrical potential to photocatalysts assembled on electrodes, other strategies are waiting to be scientifically explored and understood. In this work, a Lorentz force–assisted charge carrier separation enhancement strategy is reported to improve the photocatalytic efficiency by applying a magnetic field to a photocatalytic system. The photocatalytic efficiency can be improved by 26% just by placing a permanent magnet beneath the normal photocatalytic system without any additional power supply. The mechanism by which the Lorentz force acts oppositely on the photogenerated electrons and holes is introduced, resulting in the suppression of the photoinduced charge recombination. This work provides insights into the specific role of the Lorentz force in suppressing the recombination of electron–hole pairs in their initial photogenerated states. This suppression would increase the population of charge carriers that would subsequently be transported in the semiconductor. It is believed that this strategy based on magnetic effects will initiate a new way of thinking about photoinduced charge separation. [ABSTRACT FROM AUTHOR]

Constructing uniform covalent organic framework (COF) film on substrates for electronic devices is highly desirable. Here, a simple and mild strategy is developed to prepare them by polymerization on a solid‐liquid interface. The universality of the method is confirmed by the successful preparation of five COF films with different microstructures. These films have large lateral size, controllable thickness, and high crystalline quality. And COF patterns can also be directly achieved on substrates via hydrophilic and hydrophobic interface engineering, which is in favor of preparing device array. For application studies, the PyTTA‐TPA (PyTTA: 4,4′,4′′,4′′′‐(1,3,6,8‐Tetrakis(4‐aminophenyl)pyrene and TPA: terephthalaldehyde) COF film has a high photoresponsivity of 59.79 μA W−1 at 420 nm for photoelectrochemical (PEC) detection. When employed as an active material for optoelectronic synaptic devices for the first attempt, it shows excellent light‐stimulated synaptic plasticity properties such as short‐term plasticity (STP), long‐term plasticity (LTP), and the conversion of STP to LTP, which can be used to simulate biological synaptic functions. [ABSTRACT FROM AUTHOR]

Constructing uniform covalent organic framework (COF) film on substrates for electronic devices is highly desirable. Here, a simple and mild strategy is developed to prepare them by polymerization on a solid‐liquid interface. The universality of the method is confirmed by the successful preparation of five COF films with different microstructures. These films have large lateral size, controllable thickness, and high crystalline quality. And COF patterns can also be directly achieved on substrates via hydrophilic and hydrophobic interface engineering, which is in favor of preparing device array. For application studies, the PyTTA‐TPA (PyTTA: 4,4′,4′′,4′′′‐(1,3,6,8‐Tetrakis(4‐aminophenyl)pyrene and TPA: terephthalaldehyde) COF film has a high photoresponsivity of 59.79 μA W−1 at 420 nm for photoelectrochemical (PEC) detection. When employed as an active material for optoelectronic synaptic devices for the first attempt, it shows excellent light‐stimulated synaptic plasticity properties such as short‐term plasticity (STP), long‐term plasticity (LTP), and the conversion of STP to LTP, which can be used to simulate biological synaptic functions. [ABSTRACT FROM AUTHOR]

The Dunhuang Mogao Grottoes are a significant cultural heritage site in the Silk Road, famous for its wonderful murals and statues. The rainfall causes the changes of humidity in the caves, which can easily activate the salts diseases of murals. In order to prevent the deterioration of the murals, the environmental monitoring tests were conducted to analyze the microclimate changes of the cave in rainfall weather, and proposed the risk prevention measures and suggestions. The results indicate that the temperature of caves has small change, but the humidity shows a clear trend of increase. The humidity and the duration of high humidity increases with the increase of the rainfall grade and frequency. The optimal starting time for environment control in the cave is when aatm and acave are consistent, and the relative humidity is controlled below 62%. The caves with lower layer, larger degree of openness and small volume are most vulnerable to water vapour diffusion. The environment monitoring should pay more attention to the continuous rainfall weather and the vulnerable caves. The research has great significance for the prevention of ancient mural deterioration. [ABSTRACT FROM AUTHOR]

Abstract The optical beam shift is a spatial displacement of an optical beam in geometrical optics that particularly occurs when a laser beam reflects from an interface. In this paper, the dependence of the Goos–Hänchen (GH) and Imbert–Fedorov (IF) shifts from the interface of quartz and garnet on the external direct current voltage (EDCV) are investigated by a Thorlabs BP209-IR slit beam profiler. The optical properties of the circularly polarized and linearly polarized laser beams are measured using a Thorlabs PAX 5710IR3 polarimeters. The results show that the change trend of the GH and IF shifts are the same, whereas the initial and terminal voltages are different. The maximum value of the GH and IF shifts are 20. 9 μ m and 33. 4 μ m when the EDCVs are at about 3.2 V and 2.0 V, respectively Highlights • The Goos–Hänchen and Imbert–Fedorov shifts from the interface of quartz and garnet are investigated. • The optical polarization properties of the circularly polarized and linearly polarized laser beams are measured. • The maximum Goos–Hänchen and Imbert–Fedorov shifts are 20.9 μ m and 33.4 μ m. [ABSTRACT FROM AUTHOR]

Abstract A garnet-type optical current sensor (OCS) is studied. Ta/Nd 2 Fe 14 B/Ta groove films are prepared on garnet by a magnetron sputtering method. The measurement errors of the Faraday rotation angle and the Verdet constant of the garnet-type and garnet-groove film OCSs are measured by Thorlabs polarimeters as a function of temperature. The results show that the measurement errors of the Faraday rotation angle of the garnet-type and garnet-groove film OCSs are 1.5% and 0.3%, respectively, when the current is 700 A at room temperature. The measurement error of the garnet-groove magnetic film OCS is lower than 0.3%, when the current changes from 0 to 1000 A and the temperature changes from 25 °C to 80 °C. The Verdet constant variations of the garnet-type and garnet-groove film OCSs cause different measurement errors when the temperature is changed. Highlights • A garnet-type optical current sensor (OCS) is studied. • The measurement error of Faraday rotation angle of the garnet-type OCS is 1.5%. • The measurement error of the garnet-groove film OCS is lower than 0.3%. • The Verdet constant variation of the garnet-type and garnet-groove film OCS cause different measurement errors. [ABSTRACT FROM AUTHOR]

Forests simultaneously provide multiple ecosystem services (ESs), but the trade-off and synergy among them were uncertain. Biotic and abiotic variables regulate forest ecosystem service multifunctionality (EMF); however, quantifying the relative contribution of them to EMF in natural forests at large scale was still limited. We examined the trade-off in ecosystem services and the drivers of EMF of natural temperate forests in northeast China. Six facets of ESs were derived based on 2227 national forest inventory sample plots, that is, water conservation, soil conservation, stand productivity, tree species diversity, carbon storage and soil fertility maintenance. Structural equation model was applied to quantify the driving forces of EMF including mean annual temperature (MAT), mean annual precipitation (MAP), total nitrogen (TN), soil pH (pH), stand age (Age), additive stand density index (aSDI), stand structural diversity (SSD) and tree species richness (SR). Our results indicated that the RMSD (root mean square deviation) values of the 15 ES pairs ranged from 0.13 to 0.25, and the trade-offs between biodiversity and other five ESs were high, with RMSD values greater than 0.2. We provided clear evidence that stand density was the most important driver of EMF, which affected the EMF indirectly through tree size diversity and species richness. Understanding the contribution of these factors to EMF can help to design sustainable forest management practices in northeast China aiming to foster and preserve multifunctionality. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) are crystalline porous polymers with the characteristics of a large specific surface area, controllable pore structures, high stability, and low mass density. Herein, we demonstrate the development of an exogenous coreactant-free electrochemiluminescent sensor based on a hydrazone-linked COF for sensing glucose. We synthesized a TFPPy-DMeTHz-COF with the hydrazone bond as the linkage and 2,5-dimethoxyterephthalohydrazide (DMeTHz) and 1,3,6,8-tetrakis(4-formylphenyl)pyrene (TFPPy) as the monomers. The obtained TFPPy-DMeTHz-COF exhibits high electrochemiluminescence (ECL) efficiency (21.7%) without either the addition of any coreactants or the removal of dissolved O2, and the ECL signal intensity of the TFPPy-DMeTHz-COF is 6.6 and 113-fold higher than those of TFPPy and DMeTHz, respectively. The enhanced ECL emission of the TFPPy-DMeTHz-COF is induced by OH− in PBS, and the ECL signal exhibits linear dependence on the pH value in the range from 3 to 10. When glucose is present, the addition of glucose oxidase (GOx) to the O2-containing solution generates gluconic acid, and the resultant gluconic acid can induce the decrease of the pH value and the quenching of the ECL emission of the TFPPy-DMeTHz-COF. This exogenous coreactant-free electrochemiluminescent sensor exhibits good selectivity, excellent stability, and high sensitivity with a limit of detection (LOD) of 0.031 μM, and it can accurately detect glucose in human serum. [ABSTRACT FROM AUTHOR]

Anisotropy in mechanical properties is one of the critical issues in metal additive manufacturing (AM) impeding the wider application of parts fabricated using this manufacturing technique. In this work, the anisotropy in mechanical properties of an AlSi10Mg alloy fabricated by AM was investigated in terms of grain morphology, microstructure and residual stress distribution, with a focus on changes occurring during post-AM heat treatment by isochronal annealing. It was found that microstructural inhomogeneity is the major factor that weakens the melt pool boundaries, and leads also to anisotropic mechanical properties. Volumes in the vicinity of melt pool boundaries are characterized by coarse Al–Si eutectic networks and high residual stresses, where the former are the main reason for the plastic anisotropy, and the latter increase the local strength. Post-AM heat treatment can alleviate the presence of anisotropy due to homogenization of the microstructure and a redistribution of residual stresses. The overall effect of heat treatment on mechanical strength is a balance between improvement through precipitation strengthening and weakening of grain boundary strengthening, solid solution strengthening and dislocation strengthening. Through an appropriate heat treatment process (annealing at 280 °C for 2 h), the anisotropy in mechanical properties can be effectively reduced and a good strength-elongation synergy can be obtained (strength of 350 MPa and elongation of ∼9%). This study provides new ideas for understanding and mitigating anisotropy of additively manufactured AlSi10Mg, and also has implications for the study of anisotropy of other materials. [Display omitted] • The anisotropy in mechanical properties of an AlSi10Mg alloy fabricated by AM was investigated, with a focus on changes occurring during post-AM heat treatment by isochronal annealing. • Microstructural inhomogeneity is the major factor that weakens the melt pool boundaries, and leads also to anisotropic mechanical properties. • Post-AM heat treatment can alleviate the presence of anisotropy due to homogenization of the microstructure and a redistribution of residual stresses. • A good strength-elongation synergy can be obtained (strength of 350 MPa and elongation of ∼9%) through an appropriate heat treatment process. • Strengthening behavior of the samples before and after heat treatment was discussed considering solid solution strengthening, dislocation strengthening, grain boundary strengthening, and precipitation strengthening. [ABSTRACT FROM AUTHOR]

Societal Impact Statement: Combining natural and social science approaches to conduct archeological research on wooden cultural relics is important for exploring major aspects of ancient civilizations. The Forbidden City in Beijing, China, is the largest existing wooden palace complex in the world. We examined ancient DNA of imperial wood "Nanmu" specimens taken from representative structural components of the Forbidden City, in order to provide a new perspective on the long‐standing dispute about its species. This allowed us to accurately identify and properly restore these wooden artifacts and improved our understanding of the past interactions between plant distribution, forest resources, and human activities. Summary: Exploring the life styles and production methods of past generations using plant resources can help us to improve our understanding of human civilization. Nanmu, known for its high wood quality, was exclusively used for imperial palace construction in the 15th–19th centuries in China, yet its species has been a subject of long‐standing debate.Here, we revisit this unresolved problem, using morphology and ancient DNA (aDNA) to analyze 21 centuries‐old Nanmu specimens sampled from representative palaces of the Forbidden City.Cytochemical staining demonstrated that endogenous aDNA sporadically occurs in the wood ray parenchyma cells of Nanmu specimens. High‐quality plastid genomes were retrieved from archeological woods for the first time via an aDNA capture method, with 90%–100% coverage (137,663–152,805 bp) and sequence depths of 27.05‐ to 1409.94‐fold. Utilizing these ancient genomes, our results demonstrate that Phoebe zhennan and Phoebehui are most likely the main species of Nanmu in the Forbidden City.This finding diverges from the prevailing view that Nanmu encompasses woods from the whole genus Phoebe and even its close relative Machilus. It also shows that stringent criteria were used when selecting construction materials for the Forbidden City. By combining morphological traits with aDNA analyses, we provide a new solution for identifying the species of timber used for ancient architecture, and we increase our understanding of the way in which forest resources were recognized and utilized by our ancestors despite the lack of a plant taxonomic framework in ancient times. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO2) has attracted enormous interest in abundant photocatalytic reactions, but its photocatalytic efficiency is limited by its wide bandgap and the rapid recombination of electron–hole pairs. To overcome the disadvantages of its rapid electron–hole recombination rate, herein, oxidative TiO2 was one-step fabricated using potassium permanganate (KMnO4), exhibiting improved charge separation efficiency and photocatalytic degradation performance towards methyl orange (MO). Remarkably, the first-order photodegradation rate of oxidative TiO2 is 3.68 times higher than that of pristine TiO2 under the irradiation of simulated sunlight and 2.15 times higher under ultraviolet light. This exceptional photocatalytic activity is attributed to the additional oxygen doped into the interstices of the TiO2 lattice, creating impurity states in the bandgap acting as trapping sites, thus facilitating charge separation. This work provides a promising strategy for the insertion of O atoms into the TiO2 lattice and expands the photocatalytic application of the related materials. [ABSTRACT FROM AUTHOR]

The trichomes of Arabidopsis thaliana serve as accumulation sites for heavy metals such as Cd2+, and thereby both help plants cope with heavy metal stress and detoxify the soil. These trichomes are also believed to prime plant defenses against insect herbivores in response to mechanical stimulation. Because Cd2+ in such trichomes may be beneficial for plant defenses, we hypothesized that mechanical stimulation would enhance sequestration of Cd2+ in trichomes. We quantified the distribution and concentration of Cd2+ in leaves of A. thaliana , of the glabrous mutant gl1–1 of A. thaliana , and Brassica rapa L. subsp. pekinensis (Lour.) Hanelt (Chinese cabbage) and examined how these changed following mechanical stimulation of the trichomes or leaves. Light brushing or exposure to caterpillars of Spodoptera exigua led trichomes of both A. thaliana and Chinese cabbage to accumulate Cd2+ complexes more rapidly and to a higher concentration than trichomes in unstimulated controls. Comparison to responses in leaves of gl1–1 mutants suggested that this acceleration and enhancement of Cd2+ storage requires signaling through trichomes. In wild type A. thaliana , Cd2+ was found exclusively in trichomes, whereas in gl1–1 mutants, Cd2+ was found mainly in the - mesophyll cells. Results suggest a mechanobiological pathway for improving heavy metal detoxification of soils through the action of hyperaccumulator plant leaves containing non-glandular trichomes. [Display omitted] • Mechanical stimulation of trichomes accelerated Cd2+ accumulation in trichome. • Mechanical stimulation of trichomes increased Cd2+ concentration in the leaf. • Mechanical stimulation of A. thaliana trichomes depleted Cd2+ from culture plates. • Mechanical stimulation of trichomes improved the phytoextraction capacity. [ABSTRACT FROM AUTHOR]

Determining the competitor selection methods for spatial explicit competition indices is important for individual tree growth modelling and forest management. There is a lack of systematic comparisons on these methods for natural mixed forest, however. In this paper, subplots with the area of 0.0625 ha were randomly sampled from 3 one-hectare remeasured and stem-mapped plots and repeated 200 times for natural spruce-fir-broadleaf mixed forests in northeast China with a bootstrapping method. Totally 600 subplots were used to examined the optimal competitor selection methods. Nine distance-dependent competition indices (CIs) and nine main competitor selection methods were tested by including them in the individual tree basal area growth models. After the analysis of the difference in the performance between partial model (only DBH was included) and full model (both DBH and CIs were included), we found that the difference among the statistically valid methods was weak (the increase in the adjusted coefficient of determination were 0.042 to 2.014%, the mean square errors were 0.060 to 2.851%). According to the magnitude and consistency of the contribution of the selection methods for a CI and the sensitivity to distinguish the competition effects on tree growth among the constituent tree species, we comprehensively concluded that the optimal competitor selection method was dependent on the CI, but the difference among these methods was weak. In addition, the CI from Alemdag (Alemdag IS (1978) Evaluation of some competition indexes for the prediction of diameter increment in planted white spruce. Information Report Forest Management Institute (Canada) No. FMR-X-108.) with the gradually expanding radius of circle method and 8 m radius of influence circle was the best combination which could efficiently detect the difference in competition effects on tree growth among tree species groups. [ABSTRACT FROM AUTHOR]

Facile synthesis and post‐processing of covalent organic frameworks (COFs) under mild synthetic conditions are highly sought after and important for widespread utilizations in catalysis and energy storage. Here we report the synthesis of the chemically stable aza‐fused COFs BPT‐COF and PT‐COF by a liquid‐phase method. The process involves the spontaneous polycondensation of vicinal diamines and vicinal diketones, and is driven by the near‐equilibrium growth of COF domains at a very low monomer concentration. The method permits in situ assembly of COFs and COF‐GO hybrid materials and leads to the formation of a uniform conducting film on arbitrary substrates on vacuum filtration. When used as electrocatalysts, the as‐prepared membranes show a fast hydrogen evolution reaction (HER) with a low overpotential (45 mV at 10 mA cm−2) and a small Tafel slope (53 mV dec−1), which are the best among metal‐free catalysts. Our results may open a new route towards the preparation of highly π‐conjugated COFs for multifunctional applications. [ABSTRACT FROM AUTHOR]

Facile synthesis and post‐processing of covalent organic frameworks (COFs) under mild synthetic conditions are highly sought after and important for widespread utilizations in catalysis and energy storage. Here we report the synthesis of the chemically stable aza‐fused COFs BPT‐COF and PT‐COF by a liquid‐phase method. The process involves the spontaneous polycondensation of vicinal diamines and vicinal diketones, and is driven by the near‐equilibrium growth of COF domains at a very low monomer concentration. The method permits in situ assembly of COFs and COF‐GO hybrid materials and leads to the formation of a uniform conducting film on arbitrary substrates on vacuum filtration. When used as electrocatalysts, the as‐prepared membranes show a fast hydrogen evolution reaction (HER) with a low overpotential (45 mV at 10 mA cm−2) and a small Tafel slope (53 mV dec−1), which are the best among metal‐free catalysts. Our results may open a new route towards the preparation of highly π‐conjugated COFs for multifunctional applications. [ABSTRACT FROM AUTHOR]

Heterostructured catalysts play a significant role in the photodegradation of pollutants in wastewater. Combining the large surface of nanobelts with the high photocatalytic property of titanium dioxide (TiO 2) nanoparticles is a promising method for preparing photocatalysts, which have an advanced photocatalytic activity and are easy to precipitate. In this work, titanium dioxide nanobelts (NB) and acid corroded titanium dioxide nanobelts (C-NB) were synthesized via a hydrothermal process under alkaline conditions. Their surfaces were then loaded with palladium oxide (PdO) nanoparticles to prepare heterostructured photocatalysts (PdO-NB and PdO-C-NB) by a well-designed chemical precipitation method. The photodegradation efficiencies of the four catalysts for phenol, as well as for methyl orange, were tested and the order of degradation efficiency was found to be PdO-C-NB > PdO-NB > C-NB > NB. A degradation efficiency of 61% for phenol was achieved within 90 min using PdO-C-NB, which was nearly twice as much as using NB. The enhanced photocatalytic property of PdO-C-NB was due to the large specific surface area, abundant photocatalytic active sites and the low recombination rate of electron-hole pairs. Therefore, the degradation of phenol and methyl orange was speeded up considerably. Considering the high catalytic activity of PdO-C-NB, the heterostructure catalyst is of great significance to the degradation of organic wastewater, and has an important impact on our ecological environment and human health. • PdO loaded heterostructures nanobelts were synthesized by chemical deposition. • PdO-C-NB had a low recombination rate of photo-induced charge carrier. • PdO-C-NB achieved a high photocatalytic degradation of phenol. [ABSTRACT FROM AUTHOR]

2D metal‐organic framework (MOF) film as the active layer show promising application prospects in various fields including sensors, catalysis, and electronic devices. However, exploring the application of 2D MOF film in the field of artificial synapses has not been implemented yet. In this work, we fabricated a novel 2D MOF film (Cu‐THPP, THPP=5,10,15,20‐Tetrakis(4‐hydroxyphenyl)‐21H,23H‐porphine), and further used it as an active layer to explore the application in the simulation of human brain synapses. It shows excellent light‐stimulated synaptic plasticity properties, and exhibits the foundation function of synapses such as long‐term plasticity (LTP), short‐term plasticity (STP), and the conversion of STP to LTP. Most critically, the MOF based artificial synaptic device exhibits an excellent stability in atmosphere. This work opens the door for the application of 2D MOF film in the simulation of human brain synapses. [ABSTRACT FROM AUTHOR]

2D metal‐organic framework (MOF) film as the active layer show promising application prospects in various fields including sensors, catalysis, and electronic devices. However, exploring the application of 2D MOF film in the field of artificial synapses has not been implemented yet. In this work, we fabricated a novel 2D MOF film (Cu‐THPP, THPP=5,10,15,20‐Tetrakis(4‐hydroxyphenyl)‐21H,23H‐porphine), and further used it as an active layer to explore the application in the simulation of human brain synapses. It shows excellent light‐stimulated synaptic plasticity properties, and exhibits the foundation function of synapses such as long‐term plasticity (LTP), short‐term plasticity (STP), and the conversion of STP to LTP. Most critically, the MOF based artificial synaptic device exhibits an excellent stability in atmosphere. This work opens the door for the application of 2D MOF film in the simulation of human brain synapses. [ABSTRACT FROM AUTHOR]

2D metal‐organic framework (MOF) film as the active layer show promising application prospects in various fields including sensors, catalysis, and electronic devices. However, exploring the application of 2D MOF film in the field of artificial synapses has not been implemented yet. In this work, we fabricated a novel 2D MOF film (Cu‐THPP, THPP=5,10,15,20‐Tetrakis(4‐hydroxyphenyl)‐21H,23H‐porphine), and further used it as an active layer to explore the application in the simulation of human brain synapses. It shows excellent light‐stimulated synaptic plasticity properties, and exhibits the foundation function of synapses such as long‐term plasticity (LTP), short‐term plasticity (STP), and the conversion of STP to LTP. Most critically, the MOF based artificial synaptic device exhibits an excellent stability in atmosphere. This work opens the door for the application of 2D MOF film in the simulation of human brain synapses. [ABSTRACT FROM AUTHOR]

Most of covalent organic frameworks (COFs) are non or weakly emissive due to either the molecular thermal motion-mediated energy dissipation or the aggregation-caused quenching (ACQ) effect. Herein, we synthesize an imine-linked COF (TFPPy-TPh-COF) with high electrochemiluminescence (ECL) emission and the capability of eliminating the ACQ effect and further construct an ECL sensor for malathion detection. The imine-linked COF is obtained by the condensation reaction of (1,1':3′,1″-terphenyl)-4,4″-diamine (TPh) and 1,3,6,8-tetrakis(p -formylphenyl)pyrene (TFPPy), and it has higher ECL efficiency than TFPPy aggregates due to the separation of ACQ luminophores (i.e., TFPPy) from each other by TPh and the restriction of intramolecular motions of TFPPy and TPh to reduce the nonradiative decay. The efficient quenching of ECL is achieved by electrochemiluminescence resonance energy transfer (ERET) from the excited state of the TFPPy-TPh-COF to zeolite imidazolate framework-8 (ZIF-8) and the steric hindrance of ZIF-8. Acetylcholinesterase (AChE) can enzymatically hydrolyze acetylcholine (ACh) to generate acetic acid. The resultant acetic acid can trigger the dissolution of ZIF-8 to produce an enhanced ECL signal. Malathion as an organophosphorus pesticide serves as an AChE inhibitor to prevent the production of acetic acid, inducing the decrease of ECL signal. This sensor displays a limit of detection (LOD) of 2.44 pg/mL and a wide dynamic detection range of 0.01–1000 ng/mL. Furthermore, it can be used to detect other organophosphates pesticides (e.g., methidathion, chlorpyrifos, and paraoxon) and measure malathion in real samples (i.e., pakchoi, lettuce, and apples). [Display omitted] • We construct an electrochemiluminescent sensor for malathion detection. • This sensor exhibits a limit of detection of 2.44 pg/mL. • This sensor displays a wide dynamic detection range of 0.01–1000 ng/mL. • This sensor can measure malathion in real samples. [ABSTRACT FROM AUTHOR]

• We investigated the reaction of nitrobenzene with ozone at different conditions. • Apparent reaction kinetics was discussed and rate constants were obtained. • Higee showed significantly higher ozone mass-transfer efficiency. • Higee enhanced the apparent reaction rate between aqueous ozone and nitrobenzene. • Possible pathways for the degradation of nitrobenzene by ozone were proposed. This study investigated the apparent reaction kinetics and degradation pathways of nitrobenzene by ozone enhanced by high gravity technology in the presence of tert-butyl alcohol, a radical scavenger. A promoted effect of ozone and high gravity technology was observed in the degradation of nitrobenzene due to the enhanced mass transfer of ozone into water by unique characteristics of high gravity technology. The second order rate constant was obtained varied from 0.732 L/(mol·s) to 5.267L/(mol·s) at different operation parameters (temperature, initial pH value, high-gravity factor, initial nitrobenzene concentration and ozone dosage). A kinetic empirical model was established to reflect the effects of different operating parameters on the apparent rate constants of ozone and nitrobenzene, which showed that rate constants varied strongly with initial nitrobenzene concentration and high-gravity factor. The reaction was proved in the slow kinetics of gas-liquid reaction. Furthermore, the results of Gas Chromatography-Mass Spectrometer showed that nitrobenzene could only be degraded into intermediate products with unopened benzene ring (p -benzoquinone, phenol, catechol and hydroquinone) by ozone alone. [ABSTRACT FROM AUTHOR]

Leaf wax n- alkanes are one of the most abundant molecular biomarkers, and they have tremendous potential for climate study. To understand the relationship between distribution characteristics of terrestrial higher plant long chain n- alkanes and climate, we assessed the correlation between average chain length (ACL 25-33)/carbon preference index (CPI 25-33) and mean annual temperature (MAT), growing season temperature (GST), and mean annual precipitation (MAP) and growing season precipitation (GSP) over the Tibetan Plateau (TP). It is important to note that the distribution characteristics of these long chain n- alkanes must be determined in surface soils and surface lake sediments. Statistical analysis and multi-proxy approaches (CPI and Paq) were applied to deal with this problem. The answer was that the long-chain n- alkanes corresponding to the conditions (CPI 25-33 ≥5, aquatic macrophyte versus aquatic macrophyte and terrestrial plant ratio Paq≤0.20) were basically derived from terrestrial higher plants. Using these long chain n- alkanes to assess the correlation between ACL 25-33 /CPI 25-33 and MAT, GST, MAP and GSP, we concluded that (i) weak positive correlations between ACL 25-33 and MAT/GST were observed on the TP. Under high temperatures, the ACL values of terrestrial higher plants will increase to reduce cuticular transpiration. (ii) there are negative relationships between CPI 25-33 and MAP/GSP. (iii) based on the studies of two proxies (ACL and CPI) for paleoclimate application, the long-chain n- alkane ACL 25-33 may become a useful qualitative indicator of temperature change in paleoclimate studies from Xining Basin, Ximen Co, Glacially eroded lake, and Lake Dangxiong Co on the TP. CPI 25-33 values might serve as a qualitative indicator of precipitation in paleoclimate studies when the plant species do not vary on the TP. [ABSTRACT FROM AUTHOR]

Accurate estimate of tree biomass is essential for forest management. In recent years, several climate-sensitive allometric biomass models with diameter at breast height (D) as a predictor have been proposed for various tree species and climate zones to estimate tree aboveground biomass (AGB). But the allometric models only account for the potential effects of climate on tree biomass and do not simultaneously explain the influence of climate on D growth. In this study, based on the AGB data from 256 destructively sampled trees of three larch species randomly distributed across the five secondary climate zones in northeastern and northern China, we first developed a climate-sensitive AGB base model and a climate-sensitive D growth base model using a nonlinear least square regression separately. A compatible simultaneous model system was then developed with the climate-sensitive AGB and D growth models using a nonlinear seemingly unrelated regression. The potential effects of several temperature and precipitation variables on AGB and D growth were evaluated. The fitting results of climatic sensitive base models were compared against those of their compatible simultaneous model system. It was found that a decreased isothermality ([mean of monthly (maximum temperature-minimum temperature)]/(Maximum temperature of the warmest month-Minimum temperature of the coldest month)) and total growing season precipitation, and increased annual precipitation significantly increased the values of AGB; an increase of temperature seasonality (a standard deviation of the mean monthly temperature) and precipitation seasonality (a standard deviation of the mean monthly precipitation) could lead to the increase of D. The differences of the model fitting results between the compatible simultaneous system with the consideration of climate effects on both AGB and D growth and its corresponding climate-sensitive AGB and D growth base models were very small and insignificant (p > 0. 0 5). Compared to the base models, the inherent correlation of AGB with D was taken into account effectively by the proposed compatible model system developed with the climate-sensitive AGB and D growth models. In addition, the compatible properties of the estimated AGB and D were also addressed substantially in the proposed model system. [ABSTRACT FROM AUTHOR]

Due to deeper buried, multi-stage tectonic influences, rapid changing, and unclear originate of oil and gas in Jinlong 2 wellblock, we analyzed the volcanic reservoir characteristics and the genesis of hydrocarbon by cores, thin slices, loggings, physical properties, oil testing data, and carbon isotopes. Results demonstrated that the major lithology were pyroclastic rocks and lavas, the reservoir was generally poor and strongly homogeneous, the main reservoir space were primary pores, and the favorable reservoir mainly developed in the pyroclastic rocks of the third phase. Furthermore, the results of carbon isotopes indicated that the crude oil and dissolved gas originated from Fengcheng formation, while the condensate gas derived from Jiamuhe formation. [ABSTRACT FROM AUTHOR]

Abstract: Immobility of photocatalysts on substrates is a vital factor for the practical application of photocatalysis in polluted water/air treatment. In this study, TiO2 homogenously loaded quartz fiber felt was prepared by assembling of carboxyl-contained organic molecules functionalized TiO2 nanoparticles on the surface of amino group-modified quartz fiber by electrostatic adsorption between them and followed by an anneal process. The immobilization of TiO2 nanoparticles overcomes one main obstacle of the photocatalysts recycling in photocatalysis application. In addition, a plasma treatment endowed the hybrid photocatalyst a high hydrophilic property. Due to the homogeneous distribution of TiO2, charge carriers’ separation by carbon, and full contact between water and the photocatalyst derived from the high hydrophilia, the TiO2/quartz fiber felt shows excellent photocatalytic performance. Based on the stable loading and the capillarity effect of the contacted fibers photocatalyst, a demo capillarity-driven continuous-flow water treatment photocatalysis reactor was designed and built up. The TiO2 nanoparticle/quartz fiber hybrid photocatalyst can disposal organic contaminants in actual industrial waste water from a dyeing factory in the continuous-flow reactor. The chemical oxygen demand (COD) of the industrial waste water was decreased from 104 to 45 mg/L, overcoming the problem of deep water treatment which is difficult to solve by other methods. This study provides a new photocatalyst and reaction mode for the continuous-flow photocatalysis application.Graphical abstract: [ABSTRACT FROM AUTHOR]