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Transition metal Mn ions are highly promising cathode dopant materials. Due to the introduction of Mn ions, as lithium ions are deintercalated, Mn2+ will be transformed into Mn3+. This situation will lead to a severe Jahn-Teller effect, causing significant local lattice distortion and greatly reducing electrochemical stability. This article utilizes first-principles calculations to investigate the doping of Mg, Co, and V to weaken Jahn-Teller effect in LiMn0.5Fe0.5PO4 cathode. The oxidation-reduction processes of three doped models were analyzed, and the electronic structure and charge transfer amount between the Mn ion and the O ion were calculated for each. It was found that, when Mg ions are doped into the crystal, Mn ions will stabilize as Mn2+, thereby weakening the Jahn-Teller effect. However, the addition of V and Co will not alter the Jahn-Teller effect. The differential charge density and partial density of states (PDOS) were also calculated. It was found that only the doping of Mg ions can enable the material to achieve the lowest energy and the smallest volume change rate, which attribute to weaken the Jahn-Teller effect. Only doping with V and Co ions can achieve the highest lithium removal voltage, increasing the average lithium removal voltage from 4.22 to 4.42 V. Mechanical performance calculations show that the structures with two types of doped Mg ion are prone to shear deformation and cannot improve the ductility of the material. Additionally, it was found that the migration barrier of the three doped models was reduced to varying degrees, which is beneficial for the transition of lithium ions. Moreover, the diffusion coefficient of lithium ions also increased by 1–4 orders of magnitude. [ABSTRACT FROM AUTHOR]

This paper gives an analytical stress solution for the plane strain problem that the deep rock mass contains an arbitrarily shaped tunnel and a circular cavity subjected to in situ stresses. Based on the discovery that the mapping function for an arbitrarily shaped hole can also manage a tunnel and a circular hole mapping into two circles, the plate bounded by the two holes is conformally mapped onto an annulus. The complex variable method is used to establish the stress boundary condition, and then the two analytical functions are solved by the power series method. Comparison with ANSYS solution is made to validate the correctness of deductions and solving process. To consider practical underground engineering, the cases of different lateral stresses, distances of the two holes, sizes, and positions of the cavity are discussed. [ABSTRACT FROM AUTHOR]

The main pathological change in post-traumatic osteoarthritis (PTOA) is cartilage degeneration, which is closely related to inflammation and oxidative stress. Inflammation can cause degeneration of articular cartilage. Cartilage degeneration can also stimulate the progression of inflammation. It has been found that inflammatory cytokines can participate in the pathological process of cartilage degeneration through multiple signaling pathways, mainly mitogen-activated protein kinase, nuclear transcription factor kappa B, and Wnt–β-catenin signal transduction pathways. This review aimed at exploring the relationship between PTOA and inflammation-related cytokines by introducing the role of proinflammatory cytokines in chondrocyte destruction and extracellular matrix degradation.

Organotin-based catalysts prepared by a facile and green synthesis route were used in the acetylene hydrochlorination reaction. In detail, organotin-based catalysts were directly synthesized by supporting both organotin and nitrogen compounds on a coal-based columnar activated carbon (AC) using both incipient wetness impregnation and calcination methods. Interestingly, upon addition of nitrogen compounds, the resultant ([SnCl.sub.4] + [C.sub.16][H.sub.34][Cl.sub.2]Sn)/AC catalysts showed higher activity and stability when compared the its ([SnCl.sub.4] + [C.sub.16][H.sub.34][Cl.sub.2]Sn + [C.sub.2][N.sub.4][H.sub.4])/AC counterpart at 200 [degrees]C and a gas hourly space velocity (GHSV, [C.sub.2][H.sub.2] based) of 30 [h.sup.-1]. According to the results, organotin was demonstrated to be the active site, whereas the incorporation of nitrogen allowed partial mitigation of the loss of active components. Key words: organotin-based catalyst, organotin compounds, nitrogen compounds, acetylene hydrochlorination. Nous avons employé des catalyseurs organostanniques préparés par une voie de synthèse simple et écologique pour effectuer la réaction d'hydrochloration de l'acétylène. En particulier, nous avons synthétisé les catalyseurs organostanniques directement par adsorption des composés organostanniques et des composés azotés sur une colonne à base de charbon activé (CA) à l'aide des méthodes d'imprégnation capillaire et de calcination. Fait intéressant, lors de l'incorporation des composés azotés, le catalyseur obtenu ([SnCl.sub.4] + [C.sub.16][H.sub.34][Cl.sub.2]Sn)/CA a présenté une activité et une stabilité plus élevées comparativement à son analogue azoté ([SnCl.sub.4] + [C.sub.16][H.sub.34][Cl.sub.2]Sn + [C.sub.2][N.sub.4][H.sub.4])/CA à 200 [degrees]C, de même qu'une vitesse spatiale horaire de gaz (VSHG, pour le [C.sub.2][H.sub.2]) de 30 [h.sup.-1]. Les résultats ont montré que le composé organnostannique tenait lieu de site actif, tandis que l'incorporation d'azote permettait de réduire en partie la perte des composants actifs. [Traduit par la Rédaction] Mots-clés : catalyseur organostannique, composés organostanniques, composés azotés, hydrochloration d'acétylène., Introduction Polyvinylchloride (PVC) plays a significant role in agriculture, industry, electronic science, and national defense. (1) The industrial production of PVC is typically carried out by direct chlorination of ethylene, [...]

This paper studies the spontaneous combustion process of two kinds of oil shale to grasp the characteristics and mechanism of spontaneous combustion, which provides a theoretical basis for preventing spontaneous combustion of oil shale. Based on thermal analysis and low-temperature adsorption, the risk of spontaneous combustion of Wangqing oil shale (WQOS) and Beipiao oil shale (BPOS) (China) are studied. Based on the thermal analysis data, advanced kinetics and technology solution (AKTS) software is used to predict and evaluate the risk of spontaneous combustion. The kinetic model, which is obtained by combining the Gaussian fitting method with the peak analysis method, can effectively describe the combustion of the volatilization. The results show that, the combustion process of the volatilization can be divided into three stages. The predicted results show that, for the same initial temperature, the tendency of spontaneous combustion of BPOS is greater than that of WQOS, which is consistent with the results of thermal analysis and static oxygen absorption. [ABSTRACT FROM AUTHOR]