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排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
《Advanced Powder Technology》2022,33(12):103879
Heat transfer within ceramic feedstock powders is still unclear, which impedes optimization of the thermal and mechanical properties of the thermal sprayed coatings. The microspheres (yttria-stabilized zirconia YSZ and lanthanum zirconate LZO) were prepared via the electro-spraying assisted phase inversion method (ESP). The thermal properties of the two ESP microspheres and a commercial hollow spherical powder (HOSP) were investigated by using theoretical, experimental, and simulation methods. Thermal conductivity of the single microsphere was estimated via a novel nest model that was derived from the Maxwell-Eucken 1 and the EMT model. Thermal conductivity of a single YSZ/LZO-ESP microsphere prepared at 1100–1200 °C was within 0.36–0.75 W/m K, which was ~ 20 % lower than that of a single YSZ-HOSP microsphere with a similar porosity. Heat flux simulation showed that high tortuosity around the multi-scaled voids of the ESP microsphere led to a more efficient decrease in thermal conductivity compared with total porosity. 相似文献
2.
《International Journal of Hydrogen Energy》2022,47(70):30291-30302
Fuel cells (PEMFCs) are considered a clean alternative for the production of electricity. To improve their efficiency, it is necessary to understand the transport phenomena that determine their performance. This work analyzes the effective diffusion coefficients in the gas diffusion and catalyst layers (GDL and CL, respectively) based on theories such as effective medium approximation and percolation theory of a 3D multiphase nonisothermal model of a single channel PEMFC. We calculate polarization curves with different effective diffusion models and tortuosity factors m, n using OpenFOAM. The best model that approaches to experimental data is the Tomadakis-Sotirchos model with n = 4.0. The exponent m that represents the tortuosity due to the geometry has a high impact on the polarization curve construction compared to the exponent n. High values of diffusibility do not mean high values of current densities showing that there are other phenomena involved, such as water flooding. 相似文献
3.
Caifang Gao Mu-Pai Lee Mengjiao Li Ko-Chun Lee Feng-Shou Yang Che-Yi Lin Kenji Watanabe Takashi Taniguchi Po-Wen Chiu Chen-Hsin Lien Wen-Wei Wu Shu-Ping Lin Wenwu Li Yen-Fu Lin Junhao Chu 《Advanced functional materials》2021,31(5):2005182
The human brain is often likened to an incredibly complex and intricate computer, rather than electrical devices, consisting of billions of neuronal cells connected by synapses. Different brain circuits are responsible for coordinating and performing specific functions. The reward pathway of the synaptic plasticity in the brain is strongly related to the features of both drug addiction and relief. In the current study, a synaptic device based on layered hafnium disulfide (HfS2) is developed for the first time, to emulate the behavioral mechanisms of drug dosage modulation for neuroplasticity. A strong gate-dependent persistent photocurrent is observed, arising from the modulation of substrate-trapping events. By controlling the polarity of gate voltage, the basic functions of biological synapses are realized under a range of light spiking conditions. Furthermore, under the control of detrapping/trapping events at the HfS2/SiO2 interface, positive/negative correlations of the An/A1 index, which significantly reflected the weight change of synaptic plasticity, are realized under the same stimulation conditions for the emulation of the drug-related addition/relief behaviors in the brain. The findings provide a new advance for mimicking human brain plasticity. 相似文献
4.
Effective distribution coefficients of 9 impurities in 1,2-diphenylethane have been calculated by directional crystallization under different ambient frozen temperature. The effect of varied zone size, temperature difference between the melt and ambient frozen environment, number of zone on purity of 1,2-diphenylethane have been also investigated during the process of zone refining. The results indicate that the product purity in the intermediate purified region with varied zone size is higher 0.04%-0.2% than that with constant zone size. The product purity increases with temperature difference between the melt and ambient frozen environment. The appropriate temperature difference is adopted 50℃. The product purity in the intermediate region of sample bar with 2 molten zones is higher 0.05%-0.43% than that with 1 molten zone. In addition, the change of enthalpy and entropy between impurities and 1,2-diphenylethane have been determined. 相似文献
5.
设计实现了一种可用于脊髓神经刺激器的多通道大电流神经刺激器。提出将电极短接和插入短电流脉冲相结合的混合模式,在大电流下,能更加快速地实现电荷平衡。电路设计上,将ADC动态比较器的回踢噪声消除技术应用于神经刺激器,使得动态比较器在输入压差较小时能够输出正确的比较结果,从而将电极上残留电压保持在更安全的范围内。基于CSMC 0.25 μm BCD工艺进行设计与仿真,结果表明,在单向且最大刺激电流为4 mA、刺激脉宽为60 μs、刺激周期为750 μs的条件下,该15 V、16路神经刺激器能实现±50 mV安全电压的有源电荷平衡。 相似文献
6.
The article analyses and compares some free-to-use patent search services which are not managed by patent authorities but which may offer unique selling propositions (USPs) beyond the expected, standard, search functions. Those services selected for this study are Google Patents, Lens, Patent Inspiration, Free Patents Online, SureChEMBL and Octimine. For this comparative study a total set of 66 criteria were analysed for each of the six search services. Furthermore the USPs and perceived advantages and disadvantages were identified. The study concluded that some of these search services are better suited for general prior art searches or patent analysis while others are applicable for patent searches in specific fields like biotechnology or pharmaceuticals. 相似文献
7.
Avigail Stern Sigalit Aharon Tal Binyamin Abeer Karmi Dvir Rotem Lioz Etgar Danny Porath 《Advanced materials (Deerfield Beach, Fla.)》2020,32(12):1907812
Perovskite nanostructures have attracted much attention in recent years due to their suitability for a variety of applications such as photovoltaics, light-emitting diodes (LEDs), nanometer-size lasing, and more. These uses rely on the conductive properties of these nanostructures. However, electrical characterization of individual, thin perovskite nanowires has not yet been reported. Here, conductive atomic force microscopy characterization of individual cesium lead halide nanowires is presented. Clear differences are observed in the conductivity of nanowires containing only bromide and nanowires containing a mixture of bromide and iodide. The differences are attributed to a higher density of crystalline defects, deeper trap states, and higher inherent conductivity for nanowires with mixed bromide–iodide content. 相似文献
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10.
Kosuke Sato Akihiko Kono Hiroaki Urushibata Yoji Fujita Masato Koyama 《Electrical Engineering in Japan》2019,208(3-4):48-63
The authors developed a physics‐based equivalent circuit model of a lithium‐ion battery (LIB) whose parameters are continually updated, reflecting the theoretical calculation results of the Butler‐Volmer equation, diffusion equations of the lithium‐ion and lithium, and Nernst equations of the liquid and solid phases. The developed model was applied to the charge/discharge simulations of an LIB, and the experimental and simulated results of constant current discharges and pulsed‐charge/discharge were found to be in excellent agreement. In particular, using the developed model, analyzing transient responses of the LIB derived from the transition of the electric double layer charging to the electrode reaction is possible. These results demonstrate that the electrochemical performance of an LIB can be calculated on a circuit simulator using the developed model. 相似文献