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V-ZnCo2O4/Ni composites with rich oxygen vacancies are designed through a hydrothermal method followed by post calcination and reduction. This strategy enhanced electrical conductivity, modulated electronic structure, and increased active sites.

Hybrid supercapacitors (HSCs) as a novel electronic device for electrical energy storage have attractive prospects due to their high specific power and fast charge/discharge rates.

We have prepared hybrid supercapacitors (HSCs) based on metal oxide/nickel cobalt sulfide composite electrodes decorated with an ultrathin carbon layer (Co3O4@C@CoNi2S4). This ultrathin carbon laye...

In this work, hierarchically porous MnO/carbon (MnO/C) microsphere materials were fabricated by a facile two-step approach. The MnO precursors and the polymerization of dopamine were synthesized simultaneously by chemical solution method at room temperature. The dopamine plays a key role in the formation of MnO/C, which guides the growth of porous spherical structures and acts as a carbon source. The enhancement of electrochemical properties and electrical conductivity strongly depend on the porous structure of the composite electrodes. Benefiting from the unique structures, the optimized MnO/C electrode delivered a high specific capacitance of 378 F·g−1 at 0.1 A·g−1 and retained over 96.66% of its initial capacitance after 1000 cycles at 1 A·g−1, suggesting that MnO/C hybrid material has promising potential for practical supercapacitors.

The rational design of positive electrodes for hybrid supercapacitors is profound for applications in energy storage and conversion. Herein, we designed porous-hollow Co9S8/NiCo-Mo one-dimensional (1D) hetero-nanostructures on carbon cloth as battery-type electrodes. In particular, Ni–Co double hydroxide and Mo oxide grow on the surface of hollow Co9S8 nanowires, providing rich active sites. Meanwhile, the hollow structure of the Co9S8 nanowires is beneficial for electrolyte penetration and slows down the volume change caused by the continuous charge and discharge process. Moreover, the Co9S8/NiCo-Mo oxide/hydroxide electrode exhibits a remarkable areal capacity of 3.07 mA h cm−2 (1 mA cm−2), and a hybrid supercapacitor based on Co9S8/NiCo-Mo nanostructures and activated carbon (AC) can output a high specific energy of 37.6 W h kg−1 at a specific power of 228.7 W kg−1 with decent cycling stability (capacity retention of 87.7% after 10 000 cycles). Two connected HSCs can light up a red-light emitting diode (LED) and make the motor turn for more than 5 min. The results indicate that the unique integrated Co9S8/NiCo-Mo nanostructure shows great potential as a novel battery-type electrode for supercapacitors.

The unique feather-like arrays composing of ultrathin secondary nanowires are fabricated on nickel foam (NF) through a facile hydrothermal strategy. Thus, the enhancement of electrochemical properties especially the low charge transfer resistance strongly depends on more active sites and porosity of the morphology. Benefiting from the unique structure, the optimized NiCo2O4 electrode delivers a significantly lower charge transfer resistance of 0.32 Ω and a high specific capacitance of 450 F·g−1 at 0.5 A·g−1, as well as a superior cycling stability of 139.6% capacitance retention. The improvement of the electrochemical energy storage property proves the potential of the fabrication of various binary metal oxide electrodes for applications in the electrochemical energy field.

Although ternary cobalt nickel sulfide is a promising electrode material for supercapacitors, its wide application is limited by its relatively poor electrochemical stability, low rate capacity and inefficient nanostructure. Here, we demonstrate that the electrochemical activity of cobalt nickel sulfide can be significantly improved by synergy from a Co-MOF-derived Co3O4 skeleton. We design and fabricate petal-like Co3O4@CoNi2S4 nanowall arrays combined with carbon cloth as an excellent self-standing electrode for asymmetric supercapacitors. The Co3O4@CoNi2S4 electrode exhibits a high specific capacitance of 244.4 mA h g−1 at a current density of 1 A g−1 and an excellent rate capability of 81.3% at 16 A g−1. Furthermore, the assembled Co3O4@CoNi2S4//AC asymmetric supercapacitor (ASC) shows a high energy density of 55.6 W h kg−1 at a power density of 884.4 W kg−1, and the capacitance retention of Co3O4@CoNi2S4 is up to 86% after 10 000 cycles. It is believed that the presented work opens up a new strategy to fabricate high-performance supercapacitor electrodes.

Three-dimensional (3D) carbon nanospheres and two-dimensional (2D) carbon layer co-decorated dendritic nickel sulfide (Ni3S2) is fabricated on a nickel foam via a two-step hydrothermal process. The carbon nanospheres with the diameters ranging from 150 to 200 nm embellished on the “treetop” and the carbon layer coated uniformly on the “trunk”, which enhance the capacitive performance of the composite electrode. Herein, the amorphous carbon can further provide more efficient electron conduction path for the electrodes. With its unique superstructure, the as-fabricated carbon decorated Ni3S2 electrode exhibits a high specific capacity of 297.2 mAh g−1 at 5 mA cm−2, remarkable cycling stability (84.1% of the initial capacity) for 10,000 cycles at 10 mA cm−1. The hybrid supercapacitor fabricates by carbon decorated Ni3S2 and active carbon, which achieves a high specific energy of 62.5 Wh kg−1 at a specific power of 241.5 W kg−1. The encouraging results of the electrode make it as a potential candidate for energy storage.

In this paper the relationship between essential extensions and radical classes of lattice-ordered groups is discussed. It is proved that the polar radical classes of lattice-ordered groups are exactly essentially closed classes.

To study further the effect of head-down tilt (HDT) on slow positive potential in the event-related potentials (ERPs), the temporal and spatial features of visual ERPs changes during 2 hour HDT (-10 degrees) were compared with that during HUT (+20 degrees) in 15 normal subjects. The stimuli were consisted of two color LED flashes appeared randomly in left or right visual field (LVF or RVF) with same probability. The subjects were asked to make switch response to target signals (T) differentially: switching to left for T in LVF and to right for T in RVF, ignoring non-target signals(N). Five sets of tests were made during HUT and HDT. ERPs were obtained from 9 locations on scalp. The mean value of the ERPs in the period from 0.32-0.55 s was taken as the amplitude of slow positive potential(P400). The main results were as follows. 1) The mean amplitude of P400 decreased during HDT which was more significant at the 2nd, 3rd and 5th set of tests; 2) spatially, the reduction of mean P400 amplitude during HDT was more significant for signals from RVF and was more significant at posterior and central brain regions than that on frontal locations. As that the positive potential probably reflects the active inhibition activity in the brain during attention process, these data provide further evidence showing that the higher brain function was affected by the simulated weightlessness and that this effect was not only transient but also with interesting spatial characteristics.

The characteristics change of brain response was studied during 15 degrees head-down tilt (HDT) comparing with 45 degrees head-up tilt (HUT). The brain responses evaluated included the EEG power spectra change at rest and during mental arithmetic, and the event-related potentials (ERPs) of somatosensory, selective attention and mental arithmetic activities. The prominent feature of brain response change during HDT revealed that the brain function was inhibited to some extent. Such inhibition included that the significant increment of "40Hz" activity during HUT arithmetic almost disappeared during HDT arithmetic, and that the positive-potential effect induced by HDT presented in all kinds of ERPs measured, but the slow negative wave reflecting mental arithmetic and memory process was elongated. These data suggest that the brain function be affected profoundly by the simulated weightlessness, therefore, the brain function change during space flight should be studied systematically.

In this paper, the structure and performance of basic bidirectional associative memory (BAM) are examined and a BAM model with robust EBP (error backpropagation) algorithm (BAM-EBP) is proposed. In the BAM-EBP model, hidden layers are introduced in the net structure and an improved EBP algorithm is applied. The simulation of the basic BAM and BAM-EBP models in application to fault diagnosis for a control system and the comparison between the two models are carried out. The analysis and results show that both models were effective, but the BAM-EBP has better performance especially in fault tolerance, storage capacity, application adaptability. Future efforts on the theory exploration and application issues are addressed.

Event-related EEG spectral perturbation (ERSP) was studied in 20 right-handed subjects during selective response (SRP) and selective mental arithmetic (SMA). The input signals were one-digit number sounds (single syllable). The subjects were asked to make switch response (for SRP) or accumulative summation (for SMA) as soon as odd numbers (T) were heard and to ignore even ones (N). EEG powers were derived from 3 successive 0.5 s segments post input signal from 9 locations on scalp in 4 conditions (srT, srN, maT and maN). The ERSP was taken as the spectral change relative to that under rest control. The main results were: (i) the power of delta and theta activity increased significantly in the 1st 0.5 s in all 4 conditions but decreased in the following epochs; (ii) the theta activity revealed greatest spatial differentiation, prominent theta activity remained at Fz in the 2nd and 3rd 0.5 s in maT but not in srT; (iii) the power of alpha activity was lowest in the 1st 0.5 s and remained low level during SMA but increased in the 2nd 0.5 s during SRP; (iv) the 11–18 Hz activity augmented after the 1st 0.5 s, its dominance remained at P6 during SMA but switched from P6 to frontal locations during SRP; (v) the power of high frequency activities beyond 30 Hz decreased significantly during SRP at all locations. The temporal and spatial feature of ERSP in the 4 conditions provided further evidence indicating the functional correlates of EEG activities in each frequency band. The high frequency activity might reflect the general attention state. The dynamic change of attentional demand during information processing was probably reflected by alpha activity. The delta, theta and beta activities seemed related to different aspects of cognitive processes.