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We report a light-promoted hydroselenation of alkenes with high anti-Markovnikov selectivity. Blue light activates an aryl diselenide to generate a seleno radical with subsequent addition into an alkene to form a β-seleno carbon radical. Hydrogen atom transfer (HAT) from the selenol to the carbon radical generates the linear selenide with high selectivity in preference to the branched isomer. These studies reveal a unique β-selenium effect, where a selenide β to a carbon radical imparts high anti-selectivity for radical addition through delocalization of the HAT transition state.

As an advance in hydrofunctionalization, we herein report that alcohols add to 1,3-dienes with high regio- and enantioselectivity. Using Ni-DuPhos, we access enantioenriched allylic ethers. Through the choice of solvent-free conditions, we control the reversibility of C-O bond formation. This work showcases a rare example of methanol as a reagent in asymmetric synthesis.

We report the first enantioselective addition of pyrazoles to 1,3-dienes. Secondary and tertiary allylic pyrazoles can be generated with excellent regioselectivity. Mechanistic studies support a pathway distinct from previous hydroaminations: a Pd0 -catalyzed ligand-to-ligand hydrogen transfer (LLHT). This hydroamination tolerates a range of functional groups and advances the field of diene hydrofunctionalization.

C16H12ClFO5, monclinic, P21/c (no. 14), a = 14.7536(6) Å, b = 7.8281(3) Å, c = 14.0501(7) Å, β = 111.174(5)° $111.174(5){}^{\circ}$ , V = 1513.13(12) Å3, Z = 4, R gt(F) = 0.0367, wR ref(F 2) = 0.0865, T = 296(2) K.

AlCoCrFeNi high entropy alloy (HEA) coatings add by Y2O3 in the different mass fraction were prepared on Q235 steel matrix by laser cladding technology in this study, and the microstructure, hardness, and wear resistance of the AlCoCrFeNi high entropy alloy coatings were analyzed by X-ray diffractometer, scanning electron microscope, microhardness tester, and friction and wear tester. The results show that, the phase structure of AlCoCrFeNi HEAs coatings is composed of face-centered cubes (FCC) phase and body-centered cubes (BCC) phase. The volume fraction of BCC phase increases with the increase of Y2O3 mass fraction, while the FCC phase volume fraction shows the opposite trend. The microstructure of the AlCoCrFeNi high-entropy alloy coatings is composed of the equiaxed crystals, the addition of Y2O3 promotes the melt pool flow, makes the pores disappear gradually, improves the denseness, and makes the grains become fine. The addition of 5% Y2O3 (mass fraction) in the coatings results in the dendritic organization and the diffusely distributed YAl2 and Y2O3 phases, and the coating microhardness reaches up to HV 350, which is about twice than that of the AlCoCrFeNi high-entropy alloy coatings, showing the obvious strengthening effect. The addition of Y2O3 is beneficial to promote the formation of BCC phase and the precipitation of YAl2 phase in the coatings, which can effectively improve the hardness and wear resistance of the high entropy alloy coatings.

Introduction: Phage WO represents the sole bacteriophage identified to infect Wolbachia , exerting a range of impacts on the ecological dynamics and evolutionary trajectories of its host. Given the extensive prevalence of Wolbachia across various species, phage WO is likely among the most prolific phage lineages within arthropod populations. To examine the diversity and evolutionary dynamics of phage WO, we conducted a screening for the presence of phage WO in Wolbachia -infected cricket species from China. Methods: The presence of phage WO was detected using a PCR-based methodology. To elucidate the evolutionary forces driving phage WO diversity, analyses of intragenic recombination were conducted employing established recombination techniques, and horizontal transmission was investigated through comparative phylogenetic analysis of the phages and their hosts. Results and discussion: Out of 19 cricket species infected with Wolbachia , 18 species were found to harbor phage WO. Notably, 13 of these 18 cricket species hosted multiple phage types, with the number of types ranging from two to 10, while the remaining five species harbored a single phage type. Twelve horizontal transmission events of phage WO were identified, wherein common phage WO types were shared among different Wolbachia strains. Notably, each phage WO horizontal transfer event was associated with distinct Wolbachia supergroups, specifically supergroups A, B, and F. Previous studies have found that four Wolbachia strains infect two to five species of crickets. However, among these cricket species, in addition to the shared phage WO types, all harbored species-specific phage WO types. This suggests that Wolbachia in crickets may acquire phage WO types through horizontal viral transfer between eukaryotes, independent of Wolbachia involvement. Furthermore, nine putative recombination events were identified across seven cricket species harboring multiple phage types. These findings suggest that horizontal transmission and intragenic recombination have played a significant role in the evolution of the phage WO genome, effectively enhancing the diversity of phage WO associated with crickets. [ABSTRACT FROM AUTHOR]

A novel approach was applied to synthesize B6O using CaB6 and B2O3 powders as reactants. CaB6 and B2O3 were reacted to generate B6O and CaB2O4 at 1573 K, and the by‐product CaB2O4 was removed by acid leaching. It was found that the samples prepared in this work were oxygen deficient (B6Ox, x ≈.76–.77). The optimal molar ratio of CaB6 to B2O3 was determined to be 3:5, and excess B2O3 could not lead to a change in the value of oxygen occupancy. Scanning electron microscope images showed that regular holes similar to the morphologies of CaB6 particles were exhibited in the final samples, which could be explained by the diffusion of CaB6 during the reaction process. [ABSTRACT FROM AUTHOR]

A novel approach was applied to synthesize B6O using CaB6 and B2O3 powders as reactants. CaB6 and B2O3 were reacted to generate B6O and CaB2O4 at 1573 K, and the by‐product CaB2O4 was removed by acid leaching. It was found that the samples prepared in this work were oxygen deficient (B6Ox, x ≈.76–.77). The optimal molar ratio of CaB6 to B2O3 was determined to be 3:5, and excess B2O3 could not lead to a change in the value of oxygen occupancy. Scanning electron microscope images showed that regular holes similar to the morphologies of CaB6 particles were exhibited in the final samples, which could be explained by the diffusion of CaB6 during the reaction process. [ABSTRACT FROM AUTHOR]

C(sp3)–Cl bonds are present in numerous biologically active molecules and can also be used as a site for diversification by substitution or cross-coupling reactions. Herein, we report a remote internal site-selective C(sp3)–H bond chlorination of alkenes through sequential alkene isomerization and hydrochlorination, enabling the synthesis of both benzylic and tertiary chlorides with excellent site-selectivity. This transformation offers exciting possibilities for the late-stage chlorination of derivatives of natural products and pharmaceuticals. We also demonstrate the regioconvergent synthesis of a single alkyl chloride from unrefined mixtures of isomeric alkenes, which can be extracted directly from petrochemical sources. C(sp3)–Cl bonds are present in numerous biologically active molecules and can also be used as a site for diversification by substitution or cross-coupling reactions. Here, the authors report a remote internal site-selective C(sp3)–H bond chlorination of alkenes through sequential alkene isomerization and hydrochlorination, enabling the synthesis of both benzylic and tertiary chlorides with excellent site-selectivity. [ABSTRACT FROM AUTHOR]

Gravity data inversion is of critical importance in geophysics, encompassing a range of applications, such as the exploration of geological resources, the identification of geological structures, and the detection of groundwater resources. This study proposes a three-dimensional (3D) machine learning approach to enhance the efficiency of the aforementioned exploration tasks by leveraging gravity data. The mapping relationship between gravity data and subsurface density structures is modeled by the broad learning network, distinguished by its high training efficiency and robust modeling capability. Notably, the proposed inversion method obviates the constraints on the number of anomalies prior to the inversion process. This is achieved by setting one anomaly with varied locations for different training samples. Numerical and field data applications demonstrate the efficiency of the proposed 3D machine learning gravity data inversion method, especially in automatically determining the number of anomalies. In particular, the proposed method produced accurate density inversion results in the field application, aiding in the identification of potential oil and gas reservoirs in the target region and offering the potential for broader application in other resource exploration. The proposed inversion method can promote the construction of density structures of subsurfaces based on gravity data. [ABSTRACT FROM AUTHOR]

In this Article, we expand upon the catalytic hydrothiolation of 1,3-dienes to afford either allylic or homoallylic sulfides with high regiocontrol. Mechanistic studies support a pathway in which regioselectivity is dictated by the choice of counterion associated with the Rh center. Non-coordinating counterions, such as SbF6-, allow for η4-diene coordination to Rh complexes and result in allylic sulfides. In contrast, coordinating counterions, such as Cl-, favor neutral Rh complexes in which the diene binds η2 to afford homoallylic sulfides. We propose mechanisms that rationalize a fractional dependence on thiol for the 1,2-Markovnikov hydrothiolation while accounting for an inverse dependence on thiol in the 3,4- anti-Markovnikov pathway. Through the hydrothiolation of an essential oil (β-farnesene), we achieve the first enantioselective synthesis of (-)-agelasidine A.

We report a Rh-catalyzed hydrothiolation of 1,3-dienes, including petroleum feedstocks. Either secondary or tertiary allylic sulfides can be generated from the selective addition of a thiol to the more substituted double bond of a diene. The catalyst tolerates a wide range of functional groups, and the loading can be as low as 0.1 mol %.

We report a Rh-catalyzed hydroamination of 1,3-dienes to generate homoallylic amines. Our work showcases the first case of anti-Markovnikov selectivity in the intermolecular coupling of amines and 1,3-dienes. By tuning the ligand properties and Brønsted acid additive, we find that a combination of rac-BINAP and mandelic acid is critical for achieving anti-Markovnikov selectivity.

C9H11BrNiO8, monoclinic, P21/c (no. 14), a = 8.5077(16) Å, b = 6.7688(13) Å, c = 22.459(4) Å, β = 98.188(2)°, V = 1280.2(4) Å3, Z = 4, Rgt(F) = 0.0256, wRref(F2) = 0.0585, T = 296(2) K.

We communicate a strategy for the hydrofunctionalization of 1,3-dienes via Rh-hydride catalysis. Conjugated dienes are coupled to nucleophiles to demonstrate the feasibility of novel C-C, C-O, C-S, and C-N bond forming processes. In the presence of a chiral JoSPOphos ligand, hydroamination generates chiral allylic amines with high regio- and enantioselectivity. Tuning both the pKa and steric properties of an acid-additive is critical for enantiocontrol.

Wind tunnel test results of the aerodynamic coefficients of sector-shape iced eight bundle conductors varying with wind attack angles are presented. Then, by means of the user-defined cable elements, the aerodynamic loads are applied on the cable elements of each sub-conductor through the finite element method (FEM). In addition, the galloping responses of sectorshape iced eight bundle conductors are discussed. Finally, galloping responses, including dynamic responses (natural modes and frequencies), galloping orbits, and amplitudes of typical sector-shape iced eight bundle conductor transmission lines in the cases of different span lengths, wind velocities, and angles of wind attack are studied, respectively. These results provide useful references for a theoretical basis for the study of galloping and the technique of anti-galloping in cold regions. Key words: sector-shape ice, eight bundle conductors, aerodynamic characteristics, wind tunnel test, finite element method (FEM). Les resultats des essais en soufflerie des coefficients aerodynamiques d'un groupe de huit conducteurs couverts de glace variant en fonction des angles d'attaque du vent sont presentes. Ensuite, au moyen des elements de cable definis par l'utilisateur, les charges aerodynamiques sont appliquees sur les elements de cable de chaque sous-conducteur par la methode des elements finis (FEM). De plus, la reponse galopante du groupe de huit conducteurs couverts de glace est discutee. Enfin, les reponses galopantes, y compris les reponses dynamiques (modes et frequences naturels), les orbites galopantes et les amplitudes des lignes de transmission types d'un groupe de huit conducteurs couverts de glace dans les cas de differentes longueurs de portee, vitesses du vent et angles d'attaque du vent sont etudies, respectivement. Ces resultats procurent des references utiles pour une base theorique dans le cadre de l'etude du galop et la technique anti- galop dans les regions froides. [Traduit par la Redaction] Mots-cles : glace formee sur un secteur, groupe de huit conducteurs, caracteristiques aerodynamiques, essai en soufflerie, methode des elements finis (FEM)., 1. Introduction Eight bundle conductor 1000 kV ultrahigh voltage (UHV) transmission lines have been launched to solve the imbalance problem between electric power supply and demand. Because of the complexity [...]

The electrical resistivity method is widely used in near-surface mineral exploration. At present, the deterministic algorithm is commonly employed in three-dimensional (3-D) electrical resistivity inversion to obtain subsurface electrical structures. However, the accuracy and efficiency of deterministic inversion rely on the initial model. In practice, obtaining an initial model that approximates the true subsurface electrical structures remains challenging. To address this issue, we introduce a broad learning (BL) network to determine the initial model and utilize the limited memory quasi-Newton (L-BFGS) algorithm to conduct the 3-D electrical resistivity inversion task. The powerful mapping capability of the BL network enables one to find the model that elucidates the actual observed data. The single-layer BL network makes it efficient and easy to realize, leading to much faster network training compared to that using the deep learning network. Both the synthetic and field experiments suggest that the BL framework could effectively obtain the initial model based on observed data. Furthermore, in comparison to using a homogeneous medium as the initial model, the L-BFGS inversion with the BL framework-designed initial model improves the inversion accuracy of subsurface electrical structures and expedites the convergence speed of the iteration. This study provides an effective approach for fast initial model design in a data-driven manner when the prior information is unavailable. The proposed method can be useful in high-precision imaging of near-surface mineral electrical structures. [ABSTRACT FROM AUTHOR]

Based on the analysis of the ECC algorithms processing structure characteristics and parallel schedule on finite field level,a parallel architecture processor model for ECC was proposed which adopting the ILP and DLP.A prototype has been implemented based on the parallel architecture processor model.And storage structure in the model is also analyzed.The prototype is realized using FPGA,and synthesis,place and route have been accomplished under 0.18μm CMOS technology.The results prove that the proposed parallel architecture processor for ECC can guarantee high flexibility for arbitrary ECC algorithms and can achieve high performance.