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Using techniques in motivic homotopy theory, especially the theorem of Gheorghe, the second and the third author on the isomorphism between motivic Adams spectral sequence for C τ and the algebraic Novikov spectral sequence for B P ∗ , we compute the classical and motivic stable homotopy groups of spheres from dimension 0 to 90, except for some carefully enumerated uncertainties. [ABSTRACT FROM AUTHOR]

The recently developed hard-magnetic soft (HMS) materials manufactured by embedding high-coercivity micro-particles into soft matrices have received considerable attention from researchers in diverse fields, e.g., soft robotics, flexible electronics, and biomedicine. Theoretical investigations on large deformations of HMS structures are significant foundations of their applications. This work is devoted to developing a powerful theoretical tool for modeling and computing the complicated nonplanar deformations of flexible beams. A so-called quaternion beam model is proposed to break the singularity limitation of the existing geometrically exact (GE) beam model. The singularity-free governing equations for the three-dimensional (3D) large deformations of an HMS beam are first derived, and then solved with the Galerkin discretization method and the trust-region-dogleg iterative algorithm. The correctness of this new model and the utilized algorithms is verified by comparing the present results with the previous ones. The superiority of a quaternion beam model in calculating the complicated large deformations of a flexible beam is shown through several benchmark examples. It is found that the purpose of the HMS beam deformation is to eliminate the direction deviation between the residual magnetization and the applied magnetic field. The proposed new model and the revealed mechanism are supposed to be useful for guiding the engineering applications of flexible structures. [ABSTRACT FROM AUTHOR]

We introduce a new approach to determining the structure of topological cyclic homology by means of a descent spectral sequence. We carry out the computation for a p-adic local field with F p -coefficients, including the case p = 2 which was only covered by motivic methods except in the totally unramified case. [ABSTRACT FROM AUTHOR]

The oxygen isotope ratio of carbonate in Tridacna shell (δ18Oshell) is assumed to be precipitated in isotopic equilibrium with surrounding seawater and thus reflects a combination of the Sea surface temperature (SST) and the δ18O of seawater (δ18OSW). Accordingly, Tridacna δ18Oshell has been widely used for high-resolution paleoclimate reconstructions. However, the influences of interspecific differences, spatial heterogeneity, as well as the "growth effect" on the δ18Oshell-SST relationship, have not been fully tested. Here, we present a monthly resolved δ18Oshell record of a Tridacna squamosa specimen from Yagong Island, South China sea (SCS). Our results suggested that the monthly resolved δ18Oshell from northern SCS was dominated by the seasonal SST variations, which was highly correlated with measured SST after excluding the influence of δ18OSW. Then, the SST = f(δ18Oshell-δ18OSW) equations of all published monthly δ18Oshell records of modern Tridacna from the Indo-Pacific were collected. The resulting investigation revealed that similar SST = f(δ18Oshell-δ18OSW) equations for each shell, indicating the minor influences of spatial heterogeneity and interspecific differences. The average equation for Tridacna (Tridacna gigas, Tridacna derasa, Tridacna squamosa, Tridacna maxima and Hippopus hippopus) was SST = − 3.56 ± 1.26 (δ18Oshell-δ18Osw) + 22.44 ± 2.77 (− 0.28 ± 0.08 ‰°C−1, VPDB) (2σ), which was close to the equations set up for other mollusks (without Tridacna) and inorganic aragonite. Finally, although the growth rates varied greatly among Tridacna specimens and within different growth stages of each specimen, we did not find a significant influence of the growth rates on SST = f(δ18Oshell − δ18OSW) equations, indicating that the "growth effect" might have at best a slight impact on the δ18Oshell of Tridacna. [ABSTRACT FROM AUTHOR]

The author introduces the notion of a minimal resolution for BP*BP-comodules, and gives an effective algorithm to produce minimal resolutions. This produces the data needed in the work [3] for studying motivic stable stems up to stem 90. [ABSTRACT FROM AUTHOR]

Abstract: A new phenanthroline derivative, [1,2,5]oxadiazolo[3′,4′:5,6]pyrazino[2,3-f][1,10]phenanthroline was designed and synthesized. Its molecular structure was confirmed by single-crystal X-ray diffraction analysis. Its optoelectronic properties were systematically investigated by optical and electrochemical measurements. Thermogravimetric analysis revealed that the title compound is remarkably stable. Finally, DFT calculations further indicated that the phenanthroline derivative has potential applications in organic electronics.Graphical abstract: [ABSTRACT FROM AUTHOR]

Abstract: Herein, one-step conversion of cellulose dissolved in 1.75 mol L−1 NaOH/0.074 mol L−1 ZnO aqueous solution to organic acids was realized through a hydrothermal degradation without heterogeneous catalyst. The effects of solvent, the concentrations of NaOH and ZnO, O2 pressure, temperature and the reaction time on the yield of organic acids were investigated and discussed. The components of the degraded products were characterized with total organic carbon and high performance liquid chromatography. The results indicated that cellulose was depolymerized successfully to organic acids. Formic acid as the predominant species with 80.0% yield was obtained at the optimal conditions (150°C, 2 h, 3.0 MPa O2), which was much higher than those reported in literatures. The small amount of ZnO in the solvent played an important role not only to promote the cellulose dissolution, but also to accelerate its oxidative degradation. The main features of this one-step degradation of cellulose were the green solvent, pre-dissolution of catalyst, and high selectivity. This work opened up a new avenue for the conversion of cellulose to organic acids under mild conditions.Graphical abstract: The oxidative degradation of cellulose dissolved in NaOH/ZnO aqueous solution into organic acids was conducted under pressed O2 without heterogeneous catalyst. The yield of FA which was the main product reached up to 80.0%. [ABSTRACT FROM AUTHOR]

Catalysts play a key role in the production of cellulose acetate (CA). In this study, CA derived from bamboo cellulose (BC) was synthesized in a solution mixture of acetic acid and acetic anhydride that contains catalysts. The catalytic activities of three catalysts (i.e., sulfuric, methyl benzene sulfonic, and dodecyl benzene sulfonic acids) were investigated in terms of kinetics of acetylation, which was established according to the first-order reaction mechanism. Based on this, cellulose-based nanofibers were further prepared from the acetylated BC solution using an electrospinning technique. Results in this study may be useful for the preparation and application of nanomaterials derived from natural polymeric materials. [ABSTRACT FROM AUTHOR]

A novel and sensitive magnetic ionic liquid-based up-and-down-shaker-assisted dispersive liquid-liquid microextraction (MIL-UDSA-DLLME) was developed for the graphite furnace atomic absorption spectrometric measurement of inorganic selenium speciation from various rice matrixes. In the first microextraction step, the magnetic ionic liquid (1-butyl-3-methylimidazolium tetrachloroferrate, [Cmim][FeCl]) was selected to extract the complex of Se(IV) and 2,3-diaminonaphthalene from aqueous solution by the assistance of up-and-down-shaker vortex agitator. After the microextraction step, the magnetic ionic liquid containing target analytes was collected at the bottom of the tube by applying an external magnetic field around the test tube. Under the optimized conditions, the method present has low detection limit (0.018 μg L), wide linear dynamic range (0.03-10 μg L), and good repeatability (<3.0%, n = 10) for Se(IV). The proposed methodology was applied for separation and preconcentration of inorganic selenium in standard reference materials including GBW10010 rice, GBW10043 Liaoning rice, and GBW10045 Hunan rice with satisfactory results. The developed methodology was also successfully used for the speciation of Se(IV) and Se(VI) in different rice samples with the relative recoveries within the acceptable range of 94.9-104.8% for the addition recovery tests. [ABSTRACT FROM AUTHOR]

A Correction to this paper has been published: 10.1007/s00222-022-01134-9 [ABSTRACT FROM AUTHOR]

In this paper, the local fracture properties in a Alloy52M dissimilar metal welded joint (DMWJ) between A508 ferritic steel and 316 L stainless steel in nuclear power plants were investigated by using the single-edge notched bend (SENB) specimens, and their use in integrity assessment of DMWJ structures was analyzed. The results show that the local fracture resistance in the DMWJ is determined by local fracture mechanism, and which is mainly related to the microstructures and local strength mismatches of materials at the crack locations. The initial cracks always grow towards the materials with lower strength, and the crack path deviation is mainly controlled by the local strength mismatch. If the local fracture properties could not be used for cracks in the heat affected zones (HAZs), interface and near interface zones, the use of the fracture properties ( J-resistance curves) of base metals or weld metals following present codes will unavoidably produce non-conservative (unsafe) or excessive conservative assessment results. In most cases, the assessment results will be potentially unsafe. Therefore, it is recommended to obtain and use local mechanical and fracture properties in the integrity assessment of DMWJs. [ABSTRACT FROM AUTHOR]

In order to investigate the mechanism of stability for the wire feed laser welding process, systematic experiments are carried out in this study for 5A06 aluminum alloy. By using high speed camera, the melting dynamics of filler wires with different feed positions and feed rates are studied. The results indicate that these two factors mainly influence the characteristics of the filler wire melting dynamics and determine the stability of the welding process. The melting dynamics of filler wire can be generally characterized by three different forms: explosion, big droplet and molten metal bridge. When the filler wire melts and transits to the molten pool in the forms of explosion or big droplet, the stability of the welding process is strongly disturbed, resulting in an undesirable weld quality. In contrast, when it is in molten metal bridge form, the welding process is more stable and a uniform weld bead is achieved. [ABSTRACT FROM AUTHOR]