Coaxial fiber-shaped supercapacitors are a promising class of energy storage devices requiring high performance for flexible and miniature electronic devices.Yet,they are still struggling from inferior energy density,which comes from the limited choices in materials and structure used.Here,Zn-doped CuO nanowires were designed as 3D framework for aligned distributing high mass loading of MnO2 nanosheets.Zn could be introduced into the CuO crystal lattice to tune the covalency character and thus improve charge transport.The Zn–CuO@MnO2 as positive electrode obtained superior performance without sacrificing its areal and gravimetric capacitances with the increasing of mass loading of MnO2 due to 3D Zn–CuO framework enabling efficient electron transport.A novel category of free-standing asymmetric coaxial fiber-shaped supercapacitor based on Zn0.11CuO@MnO2 core electrode possesses superior specific capacitance and enhanced cell potential window.This asymmetric coaxial structure provides superior performance including higher capacity and better stability under deformation because of sufficient contact between the electrodes and electrolyte.Based on these advantages,the as-prepared asymmetric coaxial fiber-shaped supercapacitor exhibits a high specific capacitance of 296.6 mF cm^−2 and energy density of 133.47μWh cm^−2.In addition,its capacitance retention reaches 76.57%after bending 10,000 times,which demonstrates as-prepared device’s excellent flexibility and long-term cycling stability. 相似文献
TWIK (tandem-pore domain weak inward rectifying K+)-related spinal cord K+ channel (TRESK), a member of the two-pore domain K+ channel family, is abundantly expressed in dorsal root ganglion (DRG) neurons. It is well documented that TRESK expression is changed in several models of peripheral nerve injury, resulting in a shift in sensory neuron excitability. However, the role of TRESK in the model of spinal cord injury (SCI) has not been fully understood. This study investigates the role of TRESK in a thoracic spinal cord contusion model, and in transgenic mice overexpressed with the TRESK gene (TGTRESK). Immunostaining analysis showed that TRESK was expressed in the dorsal and ventral neurons of the spinal cord. The TRESK expression was increased by SCI in both dorsal and ventral neurons. TRESK mRNA expression was upregulated in the spinal cord and DRG isolated from the ninth thoracic (T9) spinal cord contusion rats. The expression was significantly upregulated in the spinal cord below the injury site at acute time points (6, 24, and 48 h) after SCI (p < 0.05). In addition, TRESK expression was markedly increased in DRGs below and adjacent to the injury site. TRESK was expressed in inflammatory cells. In addition, the number and fluorescence intensity of TRESK-positive neurons increased in the dorsal and ventral horns of the spinal cord after SCI. TGTRESK SCI mice showed faster paralysis recovery and higher mechanical threshold compared to wild-type (WT)-SCI mice. TGTRESK mice showed lower TNF-α concentrations in the blood than WT mice. In addition, IL-1β concentration and apoptotic signals in the caudal spinal cord and DRG were significantly decreased in TGTRESK SCI mice compared to WT-SCI mice (p < 0.05). These results indicate that TRESK upregulated following SCI contributes to the recovery of paralysis and mechanical pain threshold by suppressing the excitability of motor and sensory neurons and inflammatory and apoptotic processes. 相似文献
A new method is proposed in design of comb-drive actuators for specific voltage-displacement characteristics with finger gaps as the design parameters. The design method proposed by the author previously is further refined by adopting a more accurate model which considers fringe electric fields. The proposed method is applied to design comb-drive actuators with an aim to achieve linear tuning characteristics in mechanically tunable optical add-drop filters with microring resonators. To make an assessment of the accuracy of the proposed design method, three-dimensional electrostatic numerical analysis is conducted to obtain capacitances of the designed comb-drive actuators as functions of the moving finger displacement. Obtained capacitances are used to find the tuning characteristics (resonant wavelength vs. voltage) of the filter, in combination with the results from the author’s other work where a relationship between the resonant wavelength and the displacement of an index modulator was studied. It is found that by employing the actuators designed by the proposed method, the maximum deviation from linearity (MDL) can be reduced by 17.2 % points (from 25.7 % of the conventional design to 8.5 % of the new design). MDL is further reduced to 4.4 % by making a few modifications in the design.
This paper reports on a novel tunable capacitor with electrostatic angular vertical comb-drive (AVC) actuators. The AVC tunable capacitor creates a large offset in comb fingers through a small rotation angle-an advantage not found in conventional lateral comb-drive devices. High capacitance and large continuous tuning ratio is achieved in a compact device area. The largest tuning varactor demonstrates capacitance values between 0.27-8.6 pF-a tuning ratio of more than 31:1, the highest ever reported. The maximum quality factor Q is 273 at 1 GHz near the minimum capacitance value. 相似文献
The capacity of oyster mushroom (Pleurotus ostreatus) mycelium to produce meaty flavour compounds in the presence of amino acids and sugars was studied. The submerged liquid culture of P. ostreatus mycelium along with base medium made of defatted soybean powder, sucrose, potassium phosphate, and magnesium sulphate was incubated for 3 days at 25 °C. Cysteine, glutamine, or methionine and fructose, galactose, ribose, or xylose were added to the base medium to study the effect of amino acids and sugars on meaty flavour formation by trained panelists. The flavour compounds were isolated and identified by GC–MS and GC retention time of authentic compounds. The base medium required P. ostreatus, cysteine, ribose, and heat treatment to produce meaty flavour. The sulphur containing heterocyclic compounds such as 2,5‐diethylthiophene, 2‐formyl‐5‐methylthiophene, 3‐ethyl‐2‐formylthiophene, and dimethylformyl thiophene were responsible for meaty flavour. These compounds were formed by non‐enzymatic browning reaction between ribose and cysteine during heat treatment. 相似文献
The thin film phantom is a new type of ultrasound resolution test object. It consists of a thin planar substrate that is acoustically matched to the surrounding media. Precisely located scatterers on the surface of the substrate generate echo signals. The patterning of scatterers on the substrate allows echogenicity to be controlled as a function of position, which enables the production of a test object with highly reproducible and controllable scattering characteristics. We show that by vibrating the substrate in a suitable manner, an echo signal may be generated that simulates bidirectional flow. We demonstrate that a vibration of low amplitude at frequency f0 produces a Doppler spectral signal at f0 and -f0, within the limits of aliasing. Furthermore, by driving the film with a bandlimited noise signal, we illustrate how a velocity distribution may be simulated. A time-varying flow velocity may be simulated by varying the noise bandwidth with time. Finally, using this technique, we demonstrate a system that simulates an arterial flow pattern, including its characteristic velocity distribution in forward and reverse directions simultaneously 相似文献
Developing generic platforms to organize discrete molecular elements and nanostructures into deterministic patterns on surfaces is one of the central challenges in the field of nanotechnology. Here we review three applications of the atomic force microscope (AFM) that address this challenge. In the first, we use two-step nanografting to create patterns of self-assembled monolayers (SAMs) to drive the organization of virus particles that have been either genetically or chemically modified to bind to the SAMs. Virus-SAM chemistries are described that provide irreversible and reversible binding, respectively. In the second, we use similar SAM patterns as affinity templates that have been designed to covalently bind oligonucleotides engineered to bind to the SAMs and selected for their ability to mediate the subsequent growth of metallic nanocrystals. In the final application, the liquid meniscus that condenses at the AFM tip-substrate contact is used as a physical tool to both modulate the surface topography of a water soluble substrate and guide the hierarchical assembly of Au nanoparticles into nanowires. All three approaches can be generalized to meet the requirements of a wide variety of materials systems and thereby provide a potential route toward development of a generic platform for molecular and materials organization. 相似文献