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Direct probing of metal–oxygen chemistry at the solid/liquid interface is essential to unravel the reaction mechanism of metal–air batteries. Ambient pressure X-ray photoelectron spectroscopy (APXPS) is an effective tool to study metal–oxygen reactions but has been limited to solid-state environments. Here, for the first time, we demonstrate in situ probing of potassium oxygen reduction/evolution reaction (ORR/OER) via APXPS in ionic liquid-based air batteries. We reveal the formation and oxidation of K2O and K2O2 in K–O2 batteries, highlighting new reaction pathways in addition to the widely established one-electron process in K–O2 batteries. Importantly, we show that the formation and subsequent oxidation of K2O2 trigger irreversible cell chemistry, which could be responsible for capacity decay in K–O2 batteries. We further show that common impurities in air such as H2O and CO2 reduce chemical reversibility of ORR and OER. This study reveals root causes of irreversible cell chemistry in K–air batteries via direct probing of ionic liquid-based air batteries via APXPS, which can be widely applied to study the chemistry of solid/liquid interfaces of metal–air batteries.

Transition-metal sulfides and selenides have been widely studied as sodium ion batteries anode materials owing to large theoretical capacity. Nevertheless, tellurides in the same chalcogen group with higher densities and better conductivity are scarcely investigated as an electrode material for sodium ion batteries. In this work, CoTe with different morphologies were synthesized by a facile one-pot solvothermal method. Both the CoTe nanorods/reduced graphene oxide (CTNRs/rGO) composites and the CoTe nanotubes (CTNTs) exhibit an advanced performance for Na-ion storage when used as anode materials for sodium-ion batteries. The electrochemical reaction mechanism of the electrode was revealed by ex-situ X-ray diffraction, high resolution transmission electron microscopy and electron diffraction methods. Particularly, the CTNR/rGO has better performance with specific capacity of 306 mA h g−1 at 50 mA g−1 after 100 cycles and capacity of 200 mA h g−1 even after 200 cycles at 0.1 A g−1, which attribute to enlarged contact surface area, improved electrical conductivity and higher mechanical strength by hybridizing with rGO. Accordingly, the CTNR/rGO can be considered as promising anode materials for sodium-ion batteries.

Iron (Fe) is a crucial transition metal for all living organisms including plants; however, Fe deficiency frequently occurs in plant because only a small portion of Fe is bioavailable in soil in recent years. To cope with Fe deficiency, plants have evolved a wide range of adaptive responses from changes in morphology to altered physiology. To understand the role of nitric oxide (NO) and 24-epibrassinolide (EBR) in alleviating chlorosis induced by Fe deficiency in peanut (Arachis hypogaea L.) plants, we determined the concentration of chlorophylls, the activation, uptake, and translocation of Fe, the activities of key enzymes, such as ferric-chelate reductase (FCR), proton-translocating adenosine triphosphatase (H+-ATPase), and antioxidant enzymes, and the accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA) of peanut plants under Fe sufficiency (100 pmol L−1 ethylenediaminetetraacetic acid (EDTA)-Fe) and Fe deficiency (0 µmol L−1 EDTA-Fe). We also investigated the production of NO in peanut plants subjected to Fe deficiency with foliar application of sodium nitroprusside (SNP), a donor of NO, and/or EBR. The results showed that Fe deficiency resulted in severe chlorosis and oxidative stress, significantly decreased the concentration of chlorophylls and active Fe, and significantly increased NO production. Foliar application of NO and/or EBR increased the activity of antioxidant enzymes, superoxide dismutase, peroxidase, and catalase, and decreased the ROS and MDA concentrations, thus enhancing the resistance of plants to oxidative stress. Application of NO also significantly increased Fe translocation from the roots to the shoots and enhanced the transfer of Fe from the cell wall fraction to the cell organelle and soluble fractions. Consequently, the concentrations of available Fe and chlorophylls in the leaves were elevated. Furthermore, the activities of H+-ATPase and FCR were enhanced in the Fe-deficient plants. Simultaneously, there was a significant increase in NO production, especially in the plants that received NO, regardless of Fe supply. These suggest that NO or EBR, and, especially, their combination are effective in alleviating plant chlorosis induced by Fe deficiency.

To obtain new elicitors that could induce plant defense against pests, a series of furan carbonylhydrazones were synthesized. Phenotypic high-throughput screening of β-glucuronidase (GUS) activity was used to identify elicitors with strong activity. Integrated bioassays were conducted to acquire chemical elicitors that induce resistance in rice to the brown planthopper Nilaparvata lugens and they are not direct toxic to the pest. Our results demonstrate that these compounds have the potential to serve as new kinds of environment-friendly plant protection agents in rice.

Running time and memory consumption comparison of 10 HUI mining algorithms.Comparison tests using 9 real world and 72 synthetic datasets.d2HUP and EFIM are the top-2 performers regarding running time.d2HUP is fastest when the data is sparse or the average transaction length is large.EFIM is the most efficient algorithm regarding memory consumption. High utility itemset mining (HUIM) has emerged as an important research topic in data mining, with applications to retail-market data analysis, stock market prediction, and recommender systems, etc. However, there are very few empirical studies that systematically compare the performance of state-of-the-art HUIM algorithms. In this paper, we present an experimental evaluation on 10 major HUIM algorithms, using 9 real world and 27 synthetic datasets to evaluate their performance. Our experiments show that EFIM and d2HUP are generally the top two performers in running time, while EFIM also consumes the least memory in most cases. In order to compare these two algorithms in depth, we use another 45 synthetic datasets with varying parameters so as to study the influence of the related parameters, in particular the number of transactions, the number of distinct items and average transaction length, on the running time and memory consumption of EFIM and d2HUP. In this work, we demonstrate that, d2HUP is more efficient than EFIM under low minimum utility values and with large sparse datasets, in terms of running time; although EFIM is the fastest in dense real datasets, it is among the slowest algorithms in sparse datasets. We suggest that, when a dataset is very sparse or the average transaction length is large, and running time is favoured over memory consumption, d2HUP should be chosen. Finally, we compare d2HUP and EFIM with two newest algorithms, mHUIMiner and ULB-Miner, and find these two algorithms have moderate performance. This work has reference value for researchers and practitioners when choosing the most appropriate HUIM algorithm for their specific applications.

Lithium storage materials with porous and sheet-like structure are featured with favorable electrode/electrolyte accessibility and a shortened lithium diffusion distance, which can possess a fast electron and ion transportation. Here, a synchronous carbonization and phosphorization method was developed to synthesize flower-like CoP/C nanosheets by using Co-based metal organic complex as a precursor. The flower-like CoP/C nanosheets electrode exhibits a high initial Coulombic efficiency and excellent specific capacity. A reversible capacity of 612 mAh g −1 is obtained at a current density of 400 mA g −1 after 500 cycles. When used as a hydrogen evolution reaction electrocatalyst in acidic media, the unique flower-like CoP/C nanosheets perform an onset over potential of 151 mV and a Tafel slope of 128 mV dec −1 . As a consequence, the flower-like CoP/C nanosheets are a promising material for lithium ion batteries and hydrogen evolution reaction.

This paper studies a multi-frame visual sub-pixel measurement technique to achieve the precise positioning of the permanent magnet linear synchronous motor (PMLSM) rapidly. A new matrix multiplication discrete Fourier transform (DFT) upsampling moving least square (MLS) algorithm is proposed to improve the accuracy and robustness of PMLSM positioning. Firstly, a line-scan vision-based measurement system is designed, and an aperiodic sinusoidal fringe image is placed on the pedestal as target image. Secondly, the local upsampling cross-correlation curve of adjacent one-dimensional signals is calculated to obtain sub-pixel displacement using the matrix-multiplied DFT method. Finally, to further improve the displacement accuracy, the MLS method is applied. Simulation tests verify that the proposed method is superior to other algorithms in measurement accuracy, calculation efficiency and measurement range. The experiment results confirm the feasibility and validity of the proposed method for detecting the mover motion under different working environments.

The purpose of this paper is to study radially symmetric solutions of a parabolic–elliptic chemotaxis system (0.1) u t = Δ u − ∇ ⋅ ( f ( u ) ∇ v ) in B R × ( 0 , + ∞ ) , 0 = Δ v − μ ( t ) + g ( u ) in B R × ( 0 , + ∞ ) subject to homogeneous Neumann boundary conditions, where B R = B R ( 0 ) ⊂ R n with n ⩾ 1 , R > 0 and μ ( t ) = 1 | B R | ∫ B R g ( u ( x , t ) ) d x denotes the time-dependent spatial mean of g ( u ) . The chemosensitivity f and nonlinear signal production g are suitably regular functions. We show that the blow-up phenomenon of radially symmetric solution ( u , v ) of (0.1) in finite time for some initial datum u 0 , when f ( ξ ) ⩾ K ξ k and g ( ξ ) ⩾ L ξ l for all ξ ⩾ 1 with K , k , L , l > 0 and k + l − 1 > 2 n . However, system (0.1) admits a global bounded classical solution for arbitrary initial datum when f ( ξ ) ⩽ K ξ k and g ( ξ ) ⩽ L ξ l for all ξ ⩾ 1 with k + l − 1 2 n .

In-depth mechanistic understanding of CO2 reduction reaction (CRR) and CO2 evolution reaction (CER) is the prerequisite to develop stable and efficient Li–CO2 batteries. In this study, we investigate the redox reaction of CO2 on the porous carbon surface in ionic liquid electrolyte via synchrotron-based in situ ambient pressure X-ray photoelectron spectroscopy (APXPS) technique. We used ionic liquid to facilitate CO2 capture and stabilize CRR intermediate anions owing to its strong solvation for Li+. We demonstrate that pure CO2 reduction is not electrochemically active at room temperature on porous carbon electrode and its kinetics can be remarkably improved by H2O, which could be responsible for the discrepancy on CRR kinetics in the literature. However, in the presence of H2O, the formed LiOH gradually converted to Li2CO3 leading to severe electrolyte degradation in charging reaction. With the assistance of O2 in the ionic liquid-based electrolyte, we show, for the first time, CRR yields a low-valence amorphous carbon and Li2O2/Li2O in the Li–CO2 batteries. The formed amorphous carbon, Li2O2 and Li2O exhibit higher rechargeability and faster kinetics compared with Li2CO3-oxidation. These new findings provide direct evidence of CRR mechanism and insights in resolving the discrepancy on CRR kinetics in Li–CO2 batteries.

Effects of trace PbO on oxide films of Incoloy 800HT were investigated in simulated primary circuit water chemistry of PWR, also with proper Co addition. The trace PbO addition in high temperature water blocked the protective spinel oxides formation of the oxide films of Incoloy 800HT. XPS results indicated that the lead, added as PbO into the high temperature water, shows not only +2 valance but also +4 and 0 valances in the oxide film of 800HT co-operated with Fe, Cr and Ni to form oxides films. Potentiodynamic polarization results indicated that as PbO concentration increased, the current densities of the less protective oxide films of Incoloy 800HT decreased in a buffer solution tested at room temperature. The capacitance results indicated that the donor densities of oxidation film of Incoloy 800HT decreased as trace PbO addition into the high temperature water.

Highly-ordered TiO 2 nanotube arrays (TNTs) were fabricated by Ti sheet by electrochemical anodization. Ce and its oxide could be loaded on TNTs as cocatalysts for water splitting electrode. SEM, XRD and XPS indicated that the Ce and its oxide were a mixture of Ce, Ce 2 O 3 and CeO 2 and dispersed upper and inner TNTs. The Ce/Ce 2 O 3 /CeO 2 /TiO 2 nanotube arrays showed stronger photocurrent response, higher photoconversion efficiency (PCE) for hydrogen generation and lower flat band potential (E fb ) than TiO 2 nanotube arrays. The photoelectrochemical cell (PEC) with anode and cathode separate compartments was implied for hydrogen generation. Photoelectrochemical hydrogen production from pure water was demonstrated without external voltage using Ce/Ce 2 O 3 /CeO 2 /TNTs semiconductor electrode. By adding ethylene glycol in anode electrolyte and at E = 0.7 V (vs. open circuit potential) bias voltage, the photocurrent density reached 11.2 mA cm −2 , PCE for 6.1% and the average hydrogen production rate for 5 mL h −1 cm −2 under 450 W Xe lamp illumination. Moreover, a stable H 2 generation property was studied in the visible light region. Meanwhile, the respective modification mechanism of Ce/Ce 2 O 3 /CeO 2 cocatalysts for improving hydrogen production rate of TNTs was discussed in detail.

In this work, composite membranes consisting of triethylmethylammonium bis(fluorosulfonyl)imide (N1222FSI), poly(ethylene oxide) (PEO) and lithium bis(fluorosulfonyl) imide (LiFSI) have been produced as solid polymer electrolytes (SPEs). The composite SPEs provide good mechanical property, high ionic conductivity at 50 °C, high electrochemical and thermal stability as well as superior interfacial compatibility with lithium metal. Moreover, Li/LiFePO4 cells containing the best-performing SPE exhibit high discharge capacity and excellent cycling performance. The results show that the novel composite SPEs might be promising electrolytes applied in all-solid-state lithium batteries.

The key to success in synthesizing zeolites from natural aluminosilicate minerals is the effective activation. This article presents an energy-saving and high-efficient method based on a submolten salt (SMS) system. Taking rectorite as an example, the effects of various activation methods on the reactivity of the resulting minerals were investigated. The results showed that after being thermally treated at 900 °C, the rectorite was transformed into meta-rectorite consisting of distorted crystallized AlO6 and SiO4/AlO4 units; after being alkali-fused at 900 °C, the crystallized SiO4 units were depolymerized into disilicates (Na2SiO3/Na2Si2O7) and monosilicates (Na4SiO4), and the AlO6/AlO4 units were converted into sodium aluminates (NaAlO2/Na2Al2O4); after being SMS-activated at 250 °C, the SiO4 units were exclusively depolymerized into monosilicates, and the AlO6/AlO4 units were converted into NaAlO2 and/or Na2Al2O4. As a result, when taking the alkali-fused or SMS-activated minerals as the starting materials, pure-phase ZSM-5 zeolites were obtained.

A transition metal-free and regioselective total synthesis of 6-methylellipticine, a potent anticancer agent, was developed. This synthetic approach mainly involved two key reactions: a direct amination of multi-functional phenol via an alkylation-Smiles rearrangement protocol, and an intramolecular C–H bond arylation reaction promoted by potassium tert-butoxide. These reactions resulted in the formation of two key intermediates, diarylamine and carbazole derivative, under transition metal-free conditions. The last cyclization afforded the target product 6-methylellipticine.