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1.
The carbon vacancy in high-entropy carbides (HECs) has a significant impact on their physical and chemical properties, yet relevant studies have still been relatively few. In this study, we investigate the surface energies of HECs with variable carbon vacancies through first-principles calculations. The results show that the surface energy of the (1 0 0) surface of the stoichiometric HECs is significantly lower than that of (1 1 1) surface. With the decrease in carbon stoichiometry, the surface energies of both (1 0 0) and (1 1 1) surfaces increase gradually, which is mainly due to the weakening of covalent bonding and the decrease of metal Hirshfeld-I (HI) charges. However, the surface energy of (1 0 0) surface increases more quickly than that of (1 1 1) surface and will exceed that of (1 1 1) surface when the carbon stoichiometry decreases to a certain extent, which is primarily attributed to the greater decrease rate of metal HI charges of (1 0 0) surface. 相似文献
2.
Journal of Materials Science - The CsPbBr3/Cs4PbBr6 perovskite composite material has received wide attention due to its good stability and photoelectric properties, and it is promising to appear... 相似文献
3.
Chu Shipeng Zhang Tuqiao Zhou Xinhong Yu Tingchao Shao Yu 《Water Resources Management》2022,36(2):491-505
Water Resources Management - Real-time modeling of a water distribution system (WDS) is a critical step for the control and operation of such systems. The nodal water demand, as the most important... 相似文献
4.
Zhang Yuting Ding Chu Lu Hu Ji Wendong 《Soil Mechanics and Foundation Engineering》2022,58(6):500-506
Soil Mechanics and Foundation Engineering - Existing piles are commonly encountered during tunnel construction in congested underground areas. Tunnel-soil-pile interaction has recently attracted... 相似文献
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根据Gleeble-3500热模拟试验机测量30CrNi3MoV钢的真应力-真应变曲线,系统研究了应变速率为0.01、0.1 s-1时钢材的动态再结晶行为,并构建了其动态再结晶模型。结果表明:30CrNi3MoV钢在高温小应变速率下更容易发生动态再结晶,其热变形激活能为328.2 kJ/mol;通过加工硬化率随流变应力变化曲线(θ-σ)的拐点确定临界应变,可得动态再结晶临界应变方程为εc=0.001 22Z0.175;构建的动态再结晶体积分数及其平均晶粒尺寸模型能够较好地预测试验钢的动态再结晶体积分数及其晶粒尺寸;当应变速率为0.1 s-1、变形温度为1050 ℃时,试验钢的晶粒最细小、均匀,平均晶粒尺寸约为19.9 μm。 相似文献
7.
针对新型机器人多自由度运动机构的需求,提出了一种新型六相双定子螺旋运动永磁执行器。执行器特点在于每个定子均为六相双Y移30°绕组,两个定子铁心采用螺旋形齿槽结构,对两个定子绕组通入六相不同相序电流组合便可产生多自由度运动方式。执行器具有控制方式灵活、容错性能强、可靠性稳定等优点。首先对螺旋运动永磁执行器的结构及运行机理进行分析,推导了执行器的磁链方程、电压方程、转矩和推力方程。最后构建了瞬态三维多自由度数值分析模型,得到了磁链、电压、转矩和推力的波形,验证了运行机理的正确性。 相似文献
8.
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
9.
Optimization of room-temperature TCR of polycrystalline La0.9-xSrxK0.1MnO3 ceramics by Sr adjustment
Hongjiang Li Kaili Chu Xingrui Pu Xiaohan Yu Xiaoli Guan Shuaizhao Jin Xiang Liu 《Ceramics International》2021,47(1):94-101
High-density La0.9-xSrxK0.1MnO3 ceramics (LSKMO, A-site = La, Sr and K, 0 ≤ x ≤ 0.25) are successfully fabricated by using facile sol-gel method. Electrical properties are performed by using combination of phenomenological percolation (PP) model, double exchange (DE) mechanism, and Jahn-Teller (JT) effect. Moreover, X-ray diffraction and scanning electron microscopy are employed to analyze the structure and morphology of LSKMO ceramics. Valence states and ionic stoichiometry are assessed by using X-ray photoemission spectrometry. Results reveal that Sr2+ ions, substituting La3+ ions, significantly influenced DE mechanism and JT effect. In addition, Sr-doping plays essential role in improving electrical properties of LSKMO ceramics. At optimal doping content of x = 0.09, peak temperature coefficient of resistance (TCR) of the resistivity is found to be 11.56% K?1 at 297.15 K, which is optimal TCR for A-site K-occupied perovskite manganese oxides. These results confirm that polycrystalline LSKMO ceramics render high room-temperature TCR values due to Sr-doping. 相似文献
10.