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Their high tunability of electronic and magnetic properties makes transition‐metal oxides (TMOs) highly intriguing for fundamental studies and promising for a wide range of applications. TMOs with strong ferrimagnetism provide new platforms for tailoring the anomalous Hall effect (AHE) beyond conventional concepts based on ferromagnets, and particularly TMOs with perpendicular magnetic anisotropy (PMA) are of prime importance for today's spintronics. This study reports on transport phenomena and magnetic characteristics of the ferrimagnetic TMO NiCo2O4 (NCO) exhibiting PMA. The entire electrical and magnetic properties of NCO films are strongly correlated with their conductivities governed by the cation valence states. The AHE exhibits an unusual sign reversal resulting from a competition between intrinsic and extrinsic mechanisms depending on the conductivity, which can be tuned by the synthesis conditions independent of the film thickness. Importantly, skew‐scattering is identified as an AHE contribution for the first time in the low‐conductivity regime. Application wise, the robust PMA without thickness limitation constitutes a major advantage compared to conventional PMA materials utilized in today's spintronics. The great potential for applications is exemplified by two proposed novel device designs consisting only of NCO films that open a new route for future spintronics, such as ferrimagnetic high‐density memories. [ABSTRACT FROM AUTHOR]

Tin disulfide (SnS2) is a promising candidate for electrosynthesis of CO2‐to‐formate while the low activity and selectivity remain a great challenge. Herein, we report the potentiostatic and pulsed potential CO2RR performance of SnS2 nanosheets (NSs) with tunable S‐vacancy and exposure of Sn‐atoms or S‐atoms prepared controllably by calcination of SnS2 at different temperatures under the H2/Ar atmosphere. The catalytic activity of S‐vacancy SnS2 (Vs‐SnS2) is improved 1.8 times, but it exhibits an exclusive hydrogen evolution with about 100 % FE under all potentials investigated in the static conditions. The theoretical calculations reveal that the adsorption of *H on the Vs‐SnS2 surface is energetically more favorable than the carbonaceous intermediates, resulting in active site coverage that hinders the carbon intermediates from being adsorbed. Fortunately, the main product can be switched from hydrogen to formate by applying pulsed potential electrolysis benefiting from in situ formed partially oxidized SnS2−x with the oxide phase selective to formate and the S‐vacancy to hydrogen. This work highlights not only the Vs‐SnS2 NSs lead to exclusively H2 formation, but also provides insights into the systematic design of highly selective CO2 reduction catalysts reconstructed by pulsed potential electrolysis. [ABSTRACT FROM AUTHOR]

Microwave digestion technology is a relatively recent method for processing biological samples, but there are some problems, such as low efficiency, which require further study. As described in this paper, vegetables were decomposed by two different microwave digestion methods of high pressure low flux and low pressure high flux microwave digestion. The contents of As, Cd, Cr, Cu, Ni, Pb and Zn in the sample solutions were determined by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), and contents of Hg by Hydride Generation-Cold Atomic Fluorescence Spectrometry (HG-CAFS). As shown by the experimental results, the measured value of National Standard Reference Materials is in agreement with the certified values by the two different methods. The relative errors of the two methods were less than 21%, the relative standard deviation was less than 4% and the recovery ratios were 91.5%-103.8%. Low pressure high flux microwave digestion method is a better method of sample dissolution for large quantities of biological sample analysis because it improves the efficiency of sample digestion.

Rare gas containing cations with general formula [Rg, B, 2F]+ have been investigated theoretically by second-order Mo\ller-Plesset perturbation, coupled cluster, and complete active space self-consistent field levels of theory with correlation-consistent basis sets. Totally two types of minima, i.e., boron centered C2v symmetried RgBF2+ (Rg = Ar, Kr, and Xe) which can be viewed as loss of F- from FRgBF2 and linear FRgBF+ (Rg = Kr and Xe) are obtained at the CCSD(T)/aug-cc-pVTZ/SDD and CASSCF(10,8)/aug-cc-pVTZ/SDD levels, respectively. It is shown that the RgBF2+ are global minima followed by FRgBF+ at 170.9 and 142.2 kcal/mol on the singlet potential-energy surfaces of [Rg, B, 2F]+ (Rg = Kr and Xe) at the CASPT2(10,8) /aug-cc-pVTZ/SDD//CASSCF(10,8)/aug-cc-pVTZ/SDD, respectively. The interconversion barrier heights between RgBF2+ and FRgBF+ (Rg = Kr and Xe) are at least 39 kcal/mol. In addition, no dissociation transition state associated with RgBF2+ and FRgBF+ can be found. This suggests that RgBF2+ (Rg = Ar, Kr, and Xe) can exist as both thermodynamically and kinetically stable species, while linear FRgBF+ (Rg = Kr and Xe) can exist as metastable species compared with the lowest dissociation limit energies just like isoelectronic linear FRgBO and FRgBN-. From natural bond orbital and atoms-in-molecules calculations, it is found that the positive charge is mainly located on Rg and boron atoms for both types of minima, the Rg-B bonds of ArBF2+, KrBF2+, and XeBF2+ are mostly electrostatic, thus can be viewed as ion-induced dipole interaction; while that of linear FKrBF+ and FXeBF+ are covalent in nature. The previous experimental observation of ArBF2+ by Pepi et al. [J. Phys. Chem. B. 110, 4492 (2006)] should correspond to C2v minimum. The presently predicted spectroscopies of KrBF2+, XeBF2+, FKrBF+, and FXeBF+ should be helpful for their experimental identification in the future. [ABSTRACT FROM AUTHOR]