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Molybdenum carbide has been reported as an efficient and stable catalyst for reverse water‐gas shift (RWGS) reaction. The conventional understanding of the mechanism suggests domination of the surface phenomena, with only surface or subsurface layers partaking in the catalytic cycle. In this study, we presented a highly active MoC catalyst from carburization process, which showed a mass‐specific reaction rate over 260 μm olCO2/gcat/s ${{\rm { o}}{{\rm { l}}}_{{\rm { C}}{{\rm { O}}}_{{\rm { 2}}}}{\rm { /}}{{\rm { g}}}_{{\rm { cat}}}{\rm { /s}}}$ with dynamic carbon flux in the bulk phase of the catalyst. Through Isotopic Temperature‐Programmed Reaction (ITPR) analysis and Environmental Transmission Electron Microscopy (ETEM), we discerned dynamic carbon flow circulating between the α‐MoC bulk phase and the gas phase reactants under the RWGS reaction atmosphere. This circulation, essential to maintaining the structural stability of the metastable α‐MoC and its ultra‐high reactivity, is accompanied by thorough carbon component exchange among the bulk, the surface and the gas‐phase reactants during the reaction process. [ABSTRACT FROM AUTHOR]

Understanding the factors influencing individual tree mortality is essential for sustainable forest management, particularly for Prince Rupprech's larch (Larix gmelinii var. Principis-rupprechtii) in North China's natural forests. This study focused on 20 sample plots (20 × 20 m each) established in Shanxi Province, North China. This study compared three individual tree mortality models—Generalized Linear Model (GLM), Linear Discriminant Analysis (LDA), and Bayesian Generalized Linear Model (Bayesian GLM)—finding that both GLM and Bayesian GLM achieved approximately 0.87 validation accuracy on the test dataset. Due to its simplicity, GLM was selected as the final model. Building on the GLM model, six binning methods were applied to categorize diameter at breast height (DBH): equal frequency binning, equal width binning, cluster-based binning, quantile binning, Chi-square binning, and decision tree binning. Among these, the decision tree binning method achieved the highest performance, with an accuracy of 90.12% and an F1 score of 90.06%, indicating its effectiveness in capturing size-dependent mortality patterns. This approach provides valuable insights into factors affecting mortality and offers practical guidance for managing Larix gmelinii var. Principis-rupprechtii forests in temperate regions. [ABSTRACT FROM AUTHOR]

Author(s): Xiao Zhang [sup.1] [sup.2] , Mengtao Zhang [sup.1] , Yuchen Deng [sup.1] , Mingquan Xu [sup.3] , Luca Artiglia [sup.4] , Wen Wen [sup.5] [sup.6] , Rui Gao [sup.7] [...], The water-gas shift (WGS) reaction is an industrially important source of pure hydrogen (H.sub.2) at the expense of carbon monoxide and water.sup.1,2. This reaction is of interest for fuel-cell applications, but requires WGS catalysts that are durable and highly active at low temperatures.sup.3. Here we demonstrate that the structure (Pt.sub.1-Pt.sub.n)/[alpha]-MoC, where isolated platinum atoms (Pt.sub.1) and subnanometre platinum clusters (Pt.sub.n) are stabilized on [alpha]-molybdenum carbide ([alpha]-MoC), catalyses the WGS reaction even at 313 kelvin, with a hydrogen-production pathway involving direct carbon monoxide dissociation identified. We find that it is critical to crowd the [alpha]-MoC surface with Pt.sub.1 and Pt.sub.n species, which prevents oxidation of the support that would cause catalyst deactivation, as seen with gold/[alpha]-MoC (ref. .sup.4), and gives our system high stability and a high metal-normalized turnover number of 4,300,000 moles of hydrogen per mole of platinum. We anticipate that the strategy demonstrated here will be pivotal for the design of highly active and stable catalysts for effective activation of important molecules such as water and carbon monoxide for energy production. A stable, low-temperature water-gas shift catalyst is achieved by crowding platinum atoms and clusters on [alpha]-molybdenum carbide; the crowding protects the support from oxidation that would cause catalyst deactivation.

Altitude plays a crucial role in shaping the diversity and distribution of species in forest landscapes in mountainous regions. However, existing studies often lack comprehensive analysis of the intricate relationships among environmental factors, disturbances, and species diversity. This study aims to address this gap by thoroughly analyzing major species' diversity, distribution, and regeneration status, along with their influencing factors, across different altitudinal gradients (1850 to 2350 m). Field surveys were conducted to examine the major species in different vegetation layers of the secondary Picea forest in Guandi Mountain. The key findings from the study include the following: (1) the study area recorded a total of nine species of adult trees, belonging to eight genera in five families, fourteen species of shrubs from eight genera in five families, and fifty-two herb species representing forty-eight genera in twenty-six families. Dominant species varied across layers, with Picea asperata Mast. and Larix principis-rupprechtii Mayr. dominating the arborous layer, Lonicera ferdinandii Franch. and Cotoneaster acutifolius Turcz. in the shrub layer, and Poa pratensis L. and Duchesnea indica (Andrews.) Focke in the herb layer. (2) Altitude significantly influenced species diversity, with the most pronounced effects observed in the shrub and herb layers. (3) Tree species regeneration varied with altitude, with Picea asperata exhibiting the highest regeneration performance, particularly in the high-altitude zone (2250–2350 m). Regeneration parameters were significantly correlated with species diversity indices in both tree and shrub layers. (4) Redundancy analysis revealed that, apart from altitude, cutting (p = 0.015) influenced the species diversity of the tree layer, while annual precipitation (p = 0.006) and temperature (p = 0.01) determined the diversity of the shrub layer. Grazing (p = 0.042) was identified as a determining factor for species diversity in the herb layer. Overall, these findings provide valuable insights into the sustainable management of forest ecosystems in the study area and offer practical guidance for forest management in similar mountainous landscapes worldwide. [ABSTRACT FROM AUTHOR]

Heavy metal concentrations (Al, V, Mn, Fe, Co, Ni, Cu, Zn, and Pb) and the magnetic properties of soil and sediment samples in/around an electrolytic manganese metal (EMM) industrial estate in northern China were investigated. Potential enrichment of Mn, Zn, and Pb was found in/around the core area of the EMM industrial estate; however, the pollution load index (PLI) values did not indicate severely polluted levels. For adults, all hazard index (HI) values of noncarcinogenic risks in the soil samples were below the safe level of 1.00. For children, none of the HI values exceeded the safe level, except Mn (HI = 1.23) in one industrial estate sample. The particle size of magnetic materials was mostly in the range of stable single-domain, and coarser ferrimagnetic phases enhanced the magnetic parameters in the industrial estate soils. Highly positive correlations were found between magnetic parameters, heavy metal concentrations, and PLI values, demonstrating that the magnetic parameters are an efficient proxy for assessing heavy metal contamination. Enrichment of Mn, Zn, and Pb was mainly derived from the EMM industry. The data showed that the EMM industrial estate under cleaner production had limited adverse impacts on the adjacent environment from the perspective of heavy metal contamination. [ABSTRACT FROM AUTHOR]