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Abstract Kitaev chains in quantum dot-superconductor arrays are a promising platform for the realization of topological superconductivity. As recently demonstrated, even a two-site chain can host Majorana zero modes known as “poor man’s Majorana”. Harnessing the potential of these states for quantum information processing, however, requires increasing their robustness to external perturbations. Here, we form a two-site Kitaev chain using Yu-Shiba-Rusinov states in proximitized quantum dots. By deterministically tuning the hybridization between the quantum dots and the superconductor, we observe poor man’s Majorana states with a gap larger than 70 μeV. The sensitivity to charge fluctuations is also greatly reduced compared to Kitaev chains made with non-proximitized dots. The systematic control and improved energy scales of poor man’s Majorana states realized with Yu-Shiba-Rusinov states will benefit the realization of longer Kitaev chains, parity qubits, and the demonstration of non-Abelian physics.

Abstract Semiconductor nanowires coupled to superconductors can host Andreev bound states with distinct spin and parity, including a spin-zero state with an even number of electrons and a spin-1/2 state with odd-parity. Considering the difference in spin of the even and odd states, spin-filtered measurements can reveal the underlying ground state. To directly measure the spin of single-electron excitations, we probe an Andreev bound state using a spin-polarized quantum dot that acts as a bipolar spin filter, in combination with a non-polarized tunnel junction in a three-terminal circuit. We observe a spin-polarized excitation spectrum of the Andreev bound state, which can be fully spin-polarized, despite strong spin-orbit interaction in the InSb nanowires. Decoupling the hybrid from the normal lead causes a current blockade, by trapping the Andreev bound state in an excited state. Spin-polarized spectroscopy of hybrid nanowire devices, as demonstrated here, is proposed as an experimental tool to support the observation of topological superconductivity.

Abstract Background Enhanced recovery after surgery (ERAS) protocols are widely used worldwide. Recently, studies of the ERAS program in spinal surgery subspecialties have been reported. The aim of this study was to evaluate the impacts of ERAS in minimally invasive microdiscectomy (MD) surgery. Methods This was a retrospective cohort study of patients undergoing MD at a single center. From March 2018 to March 2021, 286 patients were in the ERAS group. A total of 140 patients from March 2017 to February 2018 were in the conventional group. The outcomes included length of stay (LOS), the postoperative numeric rating scale (NRS), complications, 30-day readmission rate, 30-day reoperation rate and cost. Moreover, perioperative factors were also evaluated. Results Compared with the conventional group, the LOS and cost were reduced in the ERAS group. There were no significant differences in the NRS, complication rate, 30-day readmission or reoperation rates between the groups. Furthermore, postoperative drainage volume, and postoperative opioid use were lower in the ERAS group. Conclusions The ERAS protocol for MD surgery reduces LOS, cost and opioid use and accelerates patient recovery.

Abstract The proximity effect in semiconductor-superconductor nanowires is expected to generate an induced gap in the semiconductor. The magnitude of this induced gap, together with the semiconductor properties like spin-orbit coupling and g-factor, depends on the coupling between the materials. It is predicted that this coupling can be adjusted through the use of electric fields. We study this phenomenon in InSb/Al/Pt hybrids using nonlocal spectroscopy. We show that these hybrids can be tuned such that the semiconductor and superconductor are strongly coupled. In this case, the induced gap is similar to the superconducting gap in the Al/Pt shell and closes only at high magnetic fields. In contrast, the coupling can be suppressed which leads to a strong reduction of the induced gap and critical magnetic field. At the crossover between the strong-coupling and weak-coupling regimes, we observe the closing and reopening of the induced gap in the bulk of a nanowire. Contrary to expectations, it is not accompanied by the formation of zero-bias peaks in the local conductance spectra. As a result, this cannot be attributed conclusively to the anticipated topological phase transition and we discuss possible alternative explanations.

Generalized short circuit ratio (gSCR) for grid strength assessment of multi-infeed high-voltage direct current (MIDC) systems is a rigorous theoretical extension of the traditional SCR, which enables SCR to be extended to MIDC systems. However, gSCR is originally based on the assumption of homogeneous MIDC systems, in which all high-voltage direct current (HVDC) converters have an identical control configuration, thus presenting challenges to applications of gSCR to inhomogeneous MIDC systems. To weaken this assumption, this paper applies matrix perturbation theory to explore the possibility of utilization of gSCR into inhomogeneous MIDC systems. Results of numerical experiments show that in inhomogeneous MIDC systems, the previously proposed gSCR can still be used without modification. However, critical gSCR (CgSCR) must be redefined by considering the characteristics of control configurations of HVDC converter. Accordingly, the difference between gSCR and redefined CgSCR can effectively quantify the pertinent AC grid strength in terms of the static-voltage stability margin. The performance of the proposed method is demonstrated in a triple-infeed inhomogeneous line commutated converter based high-voltage direct current (LCC-HVDC) system.

In the field of nonferrous metal extraction and wastewater treatment, novel electrode materials have been known as the “heart” of the whole electrochemical innovation process. It can be seen that they play a key innovative role in this process. In this study, the catalytic activity of the novel polyaniline composite electrode material prepared in the laboratory will be comprehensively evaluated, its stability and failure mechanism will be appraised, the mechanism of electrode failure will be described, the ways to improve electrode performance will be put forward, and the superior working performance of the Ti/SnO2-Sb2O5-PANI (9%) electrode material different from the traditional precious metal electrode material will be deeply explored. The research results mainly show that Ti/SnO 2-Sb2O5-PANI (9%) electrode has good stability and can run stably for 186 h when used as anode in electrolysis experiment, while Ti/SnO 2-Sb2O5 electrode has stable operation time of only 114 h. Its failure is mainly caused by the dissolution and falling off of surface coating. In addition, it shows high electrocatalytic activity, low cell voltage of 2.258 V and high current efficiency of 85 ∼ 96% during cobalt electrodeposition experiment.

Abstract Background Enhance recovery after surgery (ERAS) is a new and promising paradigm for spine surgery. The purpose of this study is to investigate the effectiveness and safety of a multimodal and evidence-based ERAS pathway to the patients undergoing anterior cervical discectomy and fusion (ACDF). Methods The patients treated with the ACDF-ERAS pathway were compared with a historical cohort of patients who underwent ACDF before ERAS pathway implementation. Primary outcome was length of stay (LOS). Secondary outcomes included cost, MacNab grading, complication rates and 90-day readmission and reoperation. And perioperative factors and postoperative complications were reviewed. Results The ERAS protocol was composed of 21 components. More patients undergoing multi-level surgery (n ≥ 3) were included in the ERAS group. The ERAS group showed a shorter LOS and a lower cost than the conventional group. The postoperative satisfaction of patients in ERAS group was better than that in conventional group. In addition, the rate of overall complications was significantly higher in the conventional group than that in the ERAS group. There were no significant differences in operative time, postoperative drainage, or 90-day readmission and reoperation. Conclusions The ACDF-tailored ERAS pathway can reduce LOS, cost and postoperative complications, and improve patient satisfaction without increasing 90-day readmission and reoperation.

A short superconducting segment can couple attached quantum dots via elastic cotunneling (ECT) and crossed Andreev reflection (CAR). Such coupled quantum dots can host Majorana bound states provided that the ratio between CAR and ECT can be controlled. Metallic superconductors have so far been shown to mediate such tunneling phenomena, albeit with limited tunability. Here, we show that Andreev bound states formed in semiconductor-superconductor heterostructures can mediate CAR and ECT over mesoscopic length scales. Andreev bound states possess both an electron and a hole component, giving rise to an intricate interference phenomenon that allows us to tune the ratio between CAR and ECT deterministically. We further show that the combination of intrinsic spin-orbit coupling in InSb nanowires and an applied magnetic field provides another efficient knob to tune the ratio between ECT and CAR and optimize the amount of coupling between neighboring quantum dots.

Regulating the adsorption behaviour of the polysulfide species is the key to achieving highly stable Li-S batteries. Here, the authors show that amorphization-induced redistribution of d orbitals enable CoO to be a favourable candidate for polysulfide adsorption and conversion.

In this letter, a new formulation of Lebesgue integration is used to evaluate the probabilistic static security of power system operation with uncertain renewable energy generation. The risk of power flow solutions violating any pre-defined operation security limits is obtained by integrating a semi-algebraic set composed of polynomials. With the high-order moments of historical data of renewable energy generation, the integration is reformulated as a generalized moment problem which is then relaxed to a semi-definite program (SDP). Finally, the effectiveness of the proposed method is verified by numerical examples.

Summary: Achieving high selectivity and activity with the oxygen reduction reaction (ORR) is significant for developing efficient energy conversion techniques and chemical production. Here, we report that selective ORRs can be achieved by tuning short-range order in amorphous and crystalline NiO nanosheets (a-NiO NSs and c-NiO NSs, respectively). X-ray absorption spectroscopy analysis reveals that the short-range order of a-NiO NSs and c-NiO NSs mainly adopt the NiO5 pyramidal and NiO6 octahedral structures, respectively. The a-NiO NSs for electrochemical H2O2 production in 0.1 M KOH exhibits both high selectivity over 90% and high activity (1 mA cm−2 at 0.66 V versus RHE), while c-NiO NSs tends to catalyze ORRs through 4-electron pathways to generate H2O. Theoretical calculations indicate that the changed short-range order of a-NiO NSs leads to alteration of Ni d-orbital states, which can regulate the adsorption orientation and strength of ∗OOH intermediates to achieve high selectivity and activity of 2-electron ORRs.

This article is devoted to providing a new feasible route to realize carbon dioxide reduction and resource utilization. With the wide electrochemical window, high thermal stability and fast mass transfer rate of molten salt electrolyte, new carbon-based materials can be synthesized on the surface of the inexpensive Fe cathode. EDS (Electron-Dispersive-Spectroscope), SEM (Scanning-Electron-Microscope) and BET (Brunauer-Emmett-Teller) analyzers are selected to detect the critical element, microstructures and specific surface area of the new carbon-based materials generated via electrolysis. It is demonstrated that eutectic carbonates’ electrochemical reduction, ranging from 450 °C to 750 °C prefers to produce carbons with no high-value structure. While carbon products are observed with honeycomb-like and platelet structures at 450 °C with an increase in current density. Additionally, the feedstock CO2 could be converted into carbon-based materials with high value such as high surface area carbon, spherical carbon and cellular porous carbon production by optimizing the electrolysis parameters of temperature, current density and molten salt conformation. This paper shows a viable way for one-pot CO2 utilization and facile production of micro-scale structure carbon materials, in line with the concept of sustainable development.

Climate warming and environmental problems caused by the excessive consumption of fossil energy and massive CO2 emissions have seriously damaged the human living environment. This paper develops a new green, efficient, and environmentally friendly CO2 capture and conversion method, which is a crucial way to alleviate the greenhouse effect. In this study, alkali metal carbonates (and the corresponding hydroxides) are fused and blended to construct a liquid molten salt electrolyte system with excellent performance, which is applied to synthesize carbon materials or carbon-based fuel gas. By regulating the electrolyte composition and electrolysis parameters, carbon-based fuels with different micro-morphologies and compositions can be prepared in a controllable manner. In pure Li2CO3 electrolyte, carbon nanotubes (CNTs) with a high value are synthesized at 750 °C with, initially, 10 mA/cm2 and, finally, with 100 mA/cm2. Carbon spheres are obtained in Li-Ca-Ba at 750 °C with 200 mA/cm2, while honeycomb carbon is generated in the electrolyte of Li-Na-K at 450 °C with 450 mA/cm2. Syngas (33.6%) or CH4-rich fuel gas (40.1%) can also be obtained by adding LiOH into the electrolyte under 500 °C at 2.0 V and 3.2 V, respectively. This paper provides a new way of utilizing CO2 resources and a new sustainable green development.

Understanding the ground state (GS) phase transitions in the quantum tunneling regime of a superconducting system is important for future qubit devices. Here, Shen, Heedt and Borsoi et al. report distinct types of fermion parity GS transitions as a function of magnetic field and gate voltages in a Coulomb-blockaded InSb–Al island.