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High-performance energy storage device is rapidly developing to meet product demands for portable and wearable electronic products. Here, ZnCo2O4 coated on nickel foam (NF) prepared by hydrothermal method is used as the anode for supercapacitors, revealing a specific capacity (92.22 mAh g−1) and a repeatable rate of performance. Furthermore, an alkyne hydrogel electrolyte (PVA/CMC/KOH) based on polyvinyl alcohol (PVA) and carboxymethyl cellulose (CMC) is constructed, and the hydrogel containing 0.1 g CMC exhibits excellent ionic conductivity (13.33 S m−1) for quick charge transfer and adequate ion transport. Considering these advantageous characteristics, a quasi-solid-state hybrid supercapacitor fabricating with ZnCo2O4, activated carbon (AC), and PVA/CMC-0.1 delivers a maximum energy density of 17.99 Wh kg−1 at a power density of 800 W kg−1, and the capacity retention rate is about 54.95% after 5000 cycles at 5 A g−1. The deterioration in cyclic characteristics mostly happen in the first 1000 cycles, which may attribute to the loss of the infiltrated KOH solution in the gel during the process of rapid charging and discharging in the starting period. After that, the cyclic characteristics become stabilized in the following cycling procedure. Furthermore, the ZnCo2O4//PVA/CMC-0.1//AC quasi-solid-state supercapacitor can maintain its performance under different bending angles, which provides a new possibility for the application of supercapacitors in flexible devices. [ABSTRACT FROM AUTHOR]

We discuss the effects of many-body coherence on the speed of evolution of ultracold atomic gases and the relation to quantum speed limits. Our approach is focused on two related systems, spinless fermions and the bosonic Tonks-Girardeau gas, which possess equivalent density dynamics but very different coherence properties. To illustrate the effect of the coherence on the dynamics, we consider squeezing an anharmonic potential which confines the particles and find that the speed of the evolution exhibits subtle but fundamental differences between the two systems. Furthermore, we explore the difference in the driven dynamics by implementing a shortcut to adiabaticity designed to reduce spurious excitations. We show that collisions between the strongly interacting bosons can lead to changes in the coherence which result in different evolution speeds and therefore different fidelities of the final states.

Statistical tests for biomarker identification and classification methods for patient grouping are two important topics in adaptive designs of clinical trials related to genomic studies. In this article, we evaluate four test methods for biomarker identification in the first stage of an adaptive design: a model-based identification method, the popular two-sided t-test, the nonparametric Wilcoxon Rank-Sum test (two-sided), and the Regularized Generalized Linear Models. For patients grouping in the second stage, we examine classification methods such as Random Forest, Elastic-net Regularized Generalized Linear Models, Support Vector Machine (SVM), Gradient Boosting Machine (GBM), and Extreme Gradient Boosting (XGBoost). Simulation studies are carried out to assess the performance of the different methods. The best identification methods are chosen based on the well-known F 1 score, while the best classification techniques are selected based on the area under a receiver operating characteristic curve (AUC). The chosen methods are then applied to the Adaptive Signature Design (ASD) with a real data set from breast cancer patients for the purpose of evaluating the performance of ASD in different situations. [ABSTRACT FROM AUTHOR]

In this work, Co(OH)2 nanosheets were successfully deposited on the hydrothermally prepared MnCo2O4.5 nanowires by the electrodeposition method to obtain the composite material MnCo2O4.5@Co(OH)2 on Ni foam. Through comparison, it is found that the performance of the composite material is obviously superior to that of single MnCo2O4.5. Thanks to the special ribbon-like structure of the composite material and the synergistic effect of the two materials, the composite material not only improves the problem of insufficient electrical conductivity but also greatly enhances the energy storage capacity. Compared with the highest specific capacity of 375.9 C·g−1 (1 A·g−1) of MnCo2O4.5 on nickel foam, the highest specific capacity of MnCo2O4.5@Co(OH)2 can reach 902.52 C·g−1 (1 A·g−1). When forming an asymmetric supercapacitor with activated carbon electrodes, the maximum energy density can reach 55.42 Wh·kg−1 (the power density is about 800.0 W·kg−1). [ABSTRACT FROM AUTHOR]