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The discovery of superconductivity in hole‐doped infinite‐layer nickelates has fueled intense research to identify the critical factor responsible for high‐Tc superconductivity. Magnetism and superconductivity are closely entangled, and elucidating the magnetic interactions in hole‐doped nickelates is critical for understanding the pairing mechanism. Here, these calculations based on the generalized Bloch theorem (GBT) and magnetic force theorem (MFT) consistently reveal that hole doping stabilizes an incommensurate (IC) spin state and increases the IC wave vector continuously, in a way strikingly similar to hole‐doped cuprates. Going further, a nonlinear Heisenberg model including first‐neighbor and third‐neighbor in‐plane magnetic interactions is developed. The analytical solutions successfully reproduce GBT and MFT results and reveal that the competition between the two magnetic interactions is the decisive factor for the IC magnetic transition. Eventually, by analyzing the doping‐controlled spin splitting of dx2−y2${d}_{{x}^2 - {y}^2}$ band and orbital‐contributed exchange interactions, direct links between hole doping, magnetization, exchange constants, and magnetic order are established. This discovery of the IC spin state, new understanding of its electronic origin, and establishment of direct connection with the paring dx2−y2${d}_{{x}^2 - {y}^2}$ electrons radically change the current understanding of the magnetic properties in hole‐doped NdNiO2 and open new perspectives for the superconducting mechanism in nickelates superconductors. [ABSTRACT FROM AUTHOR]

Highly active, durable, and cost‐effective electrodes for hydrogen evolution reaction (HER) at ultrahigh current densities (≥1 A cm−2) are extremely demanded for industrial high‐rate hydrogen production, but challenging. Here, a robust strongly coupled Ag(S)@NiO/nickel foam (NF) electrode is reported. Taking advantage of millisecond laser direct writing in liquid nitrogen technique, lattice‐matched and coherent interfaces are formed between Ag nanoparticles with stacking faults (denoted by Ag(S)) and NiO nanosheets, leading to strong interfacial electronic coupling, not only promoting H2O adsorption and dissociation on Ni2+ but also enhancing H* adsorption on intrinsically inactive but most electrically conductive Ag. Strong chemical bonding is established at NiO/NF interface, guaranteeing rapid electron transfer and excellent mechanical durability under high‐rate hydrogen evolution. The physicochemically stable electrode achieves record‐low alkaline HER overpotential of 167 and 180 mV at 1 and 1.5 A cm−2, respectively, along with negligible activity decay after 120 h test at ≈1.5 A cm−2, surpassing reported non‐platinum group metal electrocatalysts. [ABSTRACT FROM AUTHOR]

The gut microbiota play an important role in digestion, development, nutritional metabolism and detoxification in insects. The rice stem borer, Chilo suppressalis, is one of the most destructive rice pests and has caused serious economic losses to major rice‐producing areas of China. However, little is known about how its gut microbiota has adapted to different geographical environments. We investigated the gut microbiota of C. suppressalis populations collected from five sites in the typical areas of northern China using 16S rDNA gene sequencing on an Illumina MiSeq platform. In total, 453,853,707 reads and 1650 operational taxonomic units (OTUs) in 25 gut samples of C. suppressalis were obtained. We identified 697 bacterial genera from 30 phyla, and Proteobacteria and Firmicutes were the most dominant phyla. Gut bacterial richness and alpha‐diversity metrics revealed no significant differences among these populations. We detected the highest bacterial diversity in Beizhen, western Liaoning Province. Principal coordinates analysis (PCoA) and clustering analysis (UPGMA) showed no distinct gut microbial community structure of C. suppressalis in these regions. Linear discriminant analysis (LDA) effect size (LEfSe) indicated that the bacterial species exhibited significant differences among the middle, northern and western regions. Finally, PICRUSt analysis demonstrated that microbial functions closely associated with the gut microbiome mainly included membrane transport, amino acid metabolism and carbohydrate metabolism. Accordingly, our study provided important insights into the investigation of insect‐bacteria symbioses and evaluated gut microorganisms as biocontrol agents for this pest and other agricultural lepidopterans. [ABSTRACT FROM AUTHOR]

The metamorphic conditions of the Upper Permian Yangjiagou Formation in eastern Changchun, China, were evaluated based on the mineral assemblage, illite crystallinity, illite polytypism, the b dimension of illite, and the chemical composition of chlorite. The pelitic rocks in the Yangjiagou Formation are characterized by illite + kaolinite + chlorite ± mixed‐layer chlorite/smectite and detrital quartz + plagioclase. Illite in the formation has a crystallinity of 0.38–0.55 and comprises mixed 2M1 and 1Md polytypes, indicating a metamorphic temperature of >200°C. Based on the chemical composition of chlorite and the chlorite geothermometer, we estimated diagenetic to very low‐grade metamorphic conditions with temperatures of 185°C–204°C. The b dimension of illite varies from 8.992Å to 9.005Å. We used a mathematical algorithm to extend Guidotti and Sassi's (1986) diagram relating illite b dimension with temperature and pressure, and used this diagram, together with illite crystallinity and chlorite chemical composition, to semi‐quantitatively estimate the formation pressure at<1.2 kbar. These reveal that the Yangjiagou Formation has experienced very low‐grade metamorphism. [ABSTRACT FROM AUTHOR]

The quest for new 2D ferroelectric materials continues to arouse interest. Based on first‐principles calculations, here, 2D ferroelectric properties in lead chalcogenides PbXs (X = S, Se, and Te) with a thickness of two atomic layers via strain engineering is demonstrated. Although these materials are stable in a rocksalt‐type cubic structure and are intrinsically nonferroelectric materials, an appropriate mechanical strain can readily activate a paraelectric to ferroelectric phase transition and induce in‐plane electric polarization in these atomic layers. The induced polarization magnitude can be as large as 1.90 × 10−10 C m−1 at a biaxial strain of ε = 4.0%, which is comparable in magnitude to that of ultrathin ferroelectric SnTe. The Curie temperature Tc of the materials is also estimated using effective Hamiltonian simulations. The origin of the emerged ferroelectric phase is attributed to softening of the polar mode with applied strain. In addition, the band gaps of the crystals are found to be tunable with applied strain, which can be adjusted to the ideal value of 1.3 eV for photovoltaic applications. The results not only provide a new route to explore ferroelectricity in 2D materials but also suggest promising semiconducting ferroelectrics for solar applications. [ABSTRACT FROM AUTHOR]