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Based on the total factor method, this paper explores the relationship between imported product variety and enterprises’ energy efficiency by using Statistics from China. The study finds that the types of imported products considerably improve the energy efficiency of enterprises. After accounting for endogeneity, changing test methods, and using different measures, the core conclusion remains valid. Mechanism tests indicate that the technology spillover effect and competition effect are two important channels through which imported product variety enhances enterprises’ energy efficiency. Heterogeneity test results show that the types of imported products have a greater impact on improving energy efficiency.

Molybdenum is one of the important strategic metals, which is major produced from molybdenite with roasting process in production to yield MoO3 or ammonium molybdate. For the low molybdenum grade and high impurity contents of the non-standard molybdenum concentrate, which will cause the sintering during roasting, decrease the recovery of metals and cause pollution of environment. The main treatment methods of non-standard molybdenum concentrate were reviewed, which can be divided into two categories: concentrate purification and concentrate smelting. The extraction methods include roasting, atmospheric leaching and pressure oxidation technology etc. The pressure oxidation technology has a brilliant prospect for the advantages of high comprehensive recovery of copper, molybdenum and rehenium, strong adaptability of raw materials and no output of SO2 to pollute the environment in the process, which has a strong industrial application prospect. [ABSTRACT FROM AUTHOR]

Strengthening OH adsorption on electrocatalyst is crucial to promote the rate‐determining water dissociation step of alkaline hydrogen evolution reaction (HER), whereas too‐intensified OH adsorption will poison the active sites instead. This dilemma remains one of the major challenges for improving the electrocatalysts' alkaline HER activities. Herein, a surprising finding that the strongly adsorbed OH on an ultrafine quinary PtCoCuNiZn nanoalloy can be facilely desorbed via a unique gradient OH desorption pattern is reported, which tremendously boosts its alkaline HER activity. Theoretical simulations unravel that the ultrafine PtCoCuNiZn nanoalloy possesses versatile metal sites for adsorbing OH and the strongly adsorbed OH can be gradiently transferred to desorb from the ultrafine PtCoCuNiZn nanoalloy with moderate energy barriers for each transfer step that is the gradient OH desorption. In the meanwhile, the unique gradient OH desorption mode on the ultrafine PtCoCuNiZn nanoalloy is also experimentally evidenced by the in situ Raman spectroscopy and cyclic voltammetry measurements. This finding offers a fresh opportunity to expedite the alkaline HER without compromising the OH adsorption strength on electrocatalysts, which thus maximally promotes their water dissociation properties and unlocks the full potential of their alkaline HER activities. [ABSTRACT FROM AUTHOR]

Paleoenvironmental conditions significantly influence the distribution patterns and organic matter enrichment of shale. This study investigated the vertical variations of major elements, trace elements, and total organic carbon (TOC) in the Lower Carboniferous marine shale from the Yaziluo Rift Trough, South China, to understand the paleoenvironmental conditions, including redox conditions, terrigenous detrital input, paleoproductivity, and paleo-seawater depth. The Lower Carboniferous formation consists of three sedimentary facies: basin facies, lower slope facies, and upper slope facies. From the basin to the lower slope and then to the upper slope facies, TOC, quartz, and pyrite contents gradually decrease, whereas the carbonate mineral content shows an increasing trend. A continuous decline in paleo-seawater depth transformed a deep-water anoxic environment with high paleoproductivity and low detrital input in the basin facies into a semi-deep-water environment with dysoxic-oxic conditions and moderate detrital influx in the lower slope facies, evolving further into a suboxic environment with high detrital flux in the upper slope facies. The geochemistry results suggest that anoxic conditions and high paleoproductivity were the primary controls on organic matter enrichment in the siliceous shale of the basin facies. In contrast, redox conditions significantly influenced organic matter accumulation in the mixed shale of the lower slope facies, attributed to relatively low paleoproductivity in a more restricted marine setting. Additionally, the adsorption of carbon components by clay minerals facilitated the preservation of organic matter in the calcareous shale of the upper slope facies. [ABSTRACT FROM AUTHOR]

Aiming at the characteristics of low shear resistance and high filtration loss of guar gum‐fracturing fluid, a high‐efficiency organic zirconium crosslinker was prepared. In addition, the effects of different factors on the filtration coefficient and apparent viscosity of fracturing fluid were studied, and this study explores the micro mechanisms of various factors affecting the filtration coefficient from a molecular dynamics perspective. The results show that the antifiltration ability of guar gum‐fracturing fluid is inversely proportional to the fluid viscosity. The increase of crosslinker content and reservoir pressure is beneficial to improve the viscosity and antishear ability of guar gum‐fracturing fluid. When the crosslinker content is 0.25% and pressure is 30 MPa, the fracturing fluid parameters are 145 mPa·s and 2.1 × 10−2 m3 · min1/2, respectively, while the increase of reservoir temperature and the shear rate reduces the rheology and shear resistance of guar gum‐fracturing fluid, so that the viscosity and filtration coefficient of fracturing fluid at 180°C and 200 s-1 are 123 mPa·s and 2.3 × 10-2 m3·min1/2, respectively. This work not only paves a new avenue for synthesizing organic zirconium as a crosslinker but also provides an efficient measure to reduce the filtration of guar gum‐fracturing fluid on the oil and gas reservoirs. [ABSTRACT FROM AUTHOR]