排序方式： 共有19条查询结果，搜索用时 15 毫秒
1.
Weng Yalian Chen Guixiong Zhou Xiongtu Zhang Yongai Yan Qun Guo Tailiang 《Journal of Materials Science》2022,57(15):7642-7652
Journal of Materials Science - Improving the quantum yield of non-toxic InP/ZnS QDs is essential for its commercial application in illumination and displays. In this work, single size Au... 相似文献
2.
《Journal of the European Ceramic Society》2022,42(11):4528-4538
Ideal relaxor antiferroelectrics (RAFEs) have high field-induced polarization, low remnant polarization and very slim hysteresis, which can generate high recoverable energy storage Wrec and high energy storage efficiency η, thus attracting much attention for energy storage applications. True RAFEs, on the other hand, are extremely rare, and the majority of them contain environmentally hazardous lead. In this work, we use a viscous polymer rolling process to synthesize a novel and eco-friendly 0.65Bi0.5Na0.4K0.1TiO3-0.35[2/3SrTiO3-1/3Bi(Mg2/3Nb1/3)O3] (BNKT-ST-BMN) dielectric material, which possesses a very typical RAFE-like characteristic. As a result, this material has a high Wrec of 4.43 J/cm3 and a η of 86% at an electric felid of 290 kV/cm, as well as a high thermal stability of Wrec (>3 J/cm3) over a wide range of 30–140 °C at 250 kV/cm. Our findings suggest that the BNKT-ST-BMN material could be a potential candidate for use in energy storage pulse capacitors. 相似文献
3.
《International Journal of Hydrogen Energy》2023,48(64):24560-24573
Methanation is the core process of synthetic natural gas, the performance of the entire reaction system depends on precise values of the reaction condition parameters. Accurate predictions of the CO conversion rate of the methanation reaction can eliminate time-consuming and complex steps in experiments and speed up the discovery of the best reaction conditions. However, the methanation reaction is an uncertain, highly complex, and highly nonlinear process. Thus, this paper proposes a machine learning prediction model for the methanation reaction to facilitate the subsequent search for optimal reaction conditions. The reaction temperature, pressure, hydrogen–carbon ratio, water vapor content, CO2 content, and space velocity were selected as the condition variables. The CO conversion rate was the optimization objective. An extreme learning machine (ELM) was selected as a prediction model. Because the input weights and bias matrices of the ELM are randomly generated, an ELM based on a state transition simulated annealing (STASA-ELM) algorithm is proposed. The STASA algorithm was used to optimize the ELM to improve the accuracy and stability of the model. Five additional sets of experimental data were designed for the experiment, and the error between the experimental and predicted values was small. Thus, the STASA-ELM algorithm can accurately predict the conversion of CO for different values of reaction conditions. 相似文献
4.
针对许多检测模型受到数据不平衡和异常数据的复杂性等因素影响问题,提出一种以生成对抗网络(gener-ative adversarial network,GAN)为基础的数据异常检测方法.该方法利用InfoGAN网络训练生成正常数据和异常数据,构造一个推理神经网络作为生成数据与原始数据的标签生成器,之后利用第二个GAN网... 相似文献
5.
林依林;林珊玲;林志贤 《液晶与显示》2022,37(6):736-745
针对手部的高自由度问题和结构相似问题引起的三维关键点姿态估计误差,本文提出了一套联合识别、检测以及姿态估计的三维手部骨架姿态回归网络。采用基于YOLOv3的预处理网络,提出基于级联多特征热度图的二维和三维关键点检测网络,并在特征提取网络架构中引入人体骨架手部约束,利用渐进的图卷积神经网络特征增强模块对骨架关键点结果进行进一步精细化修正,完成姿态由粗到细的调整。本文与现有多种算法在不同公共数据集下进行PCK指标和AUC指标比较,本文算法在不同测试集上的AUC指标均达到最高,平均AUC精度达到92.9%。实验表明本文方法可以通过单张二维数据准确、细致地估计三维手部姿态,并且在测试集与自然场景下均有较好表现。 相似文献
6.
Soft electronics have garnered considerable attention as a promising alternative to conventional electronics with fixed shapes and sizes because of their facile and intimate shape-adaptability to complex operating environments. Their practical applications, however, have been plagued by limited maneuverability, which predominantly stemmed from tethered electrical cords or rigid/bulky power sources. Here, we present light-triggered autonomous shape-reconfigurable and locomotive rechargeable power sources (SL-PSs), in which quasi-solid-state supercapacitors (SCs) are monolithically integrated with thermoresponsive liquid crystalline polymer networks (LCNs) substrates using a device-customized printing process. The SCs are designed to enable photothermal effect as well as adjustable capacitive storage. The LCNs are synthesized to provide thermomechanical deformation by programmable anisotropic molecular contract/expansion. Upon exposure to light or heat, the SL-PSs exhibit autonomous and reversible shape-morphing within a few seconds without impairing their electrochemical performance. Moreover, the SL-PSs convey a model cargo through photothermal stimuli-induced wire-crawling and simultaneously transfer their on-board stored electrical energy, demonstrating their potential viability as an untethered soft robotic power source. 相似文献
7.
The CaAlSiN3:Eu2+ red phosphor-in-glass was prepared using bismuth borate glass as the binder for high power light excitation. B2O3–Bi2O3–Al2O3–ZnO glass powder showed good sintering behavior with CaAlSiN3:Eu2+ phosphors at around 550 °C. The phosphor-in-glass has flat surface with a thickness of about 100 μm. From the images of FE-SEM and confocal laser scanning microscope, the uniform distribution of phosphor particles inside the phosphor-in-glass was vividly and clearly observed. And the luminescent property of phosphors was not greatly affected by glasses, as shown in fluorescence spectra. When the volume radio of CaAlSiN3:Eu2+ phosphors was 50%, the sample exhibited low thermal quenching and high flexural strength of 28.5 MPa. Compared YAG:Ce3+ phosphor-in-glass with CaAlSiN3:Eu2+ phosphor-in-glass, we found bismuth borate glass had better wettability on YAG:Ce3+ particles, which caused a higher flexural strength of the YAG:Ce3+ phosphor-in-glass. 相似文献
8.
《NDT International》1988,21(6):379-384
The aim of this study is to equip the practitioner with a simple method for the solution of practical inverse problems in NDT. In this approach, complete modelling of the measuring system and examined samples has been avoided. Inversion is based on a first principles model describing the ‘ideal output’ of the system and on a semi-empirical ‘instrument function’ (IF). The imposed constraint on the model is that it should be invertible. The IF describes the degradation and distortions in the ideal response. The function should be shift invariant to enable adaption of the linear response theory. Expressions for resolution and dynamic range as a function of measurement system parameters have been developed. 相似文献
9.
Copper–zinc–tin-sulfide (Cu2ZnSnS4, abbreviated as CZTS) is a direct band gap p-type semiconductor material with high absorption coefficient. Using oleylamine as solvent/stabilizing agent and metal chlorides and sulfur particles as chemical precursors, CZTS based nanoparticles were produced and subsequently deposited as thin films on glass substrates via spin coating of the nanoinks. The effect of temperature on crystallite size and phase composition was assessed after the solution mixture was undercooled by 30, 70 or 90 °C. Upon cooling the solution from 230 to 140 °C i.e. by 90 °C, maximum refinement in the nanoparticles size was noticed with average size on the order of few nanometers. The morphological and compositional studies of the nanoparticles were performed by means of scanning electron microscope, X-ray diffraction and Fourier transform infrared spectroscopy techniques. Phase-pure CZTS formation was confirmed from fast Fourier transform (FFT) patterns and lattice fringes observed during HR-TEM examination. Characterization of the annealed spin coated films, made from nanoink containing ultrafine nanoparticles, indicated morphological changes in the film surface during air annealing at 350°C that can be attributed to depression of CZTS phase decomposition temperature. Spectrophotometric studies of the annealed films suggested quantum confinement effect through an associated increase in the band gap value from 1.34 to 2.04 eV upon reduction in the nanoparticle size caused by increasing the degree of undercooling to 90 °C. 相似文献
10.
《Solid-state electronics》1986,29(2):205-214
This paper reviews current knowledge of shallow impurity states (donors and acceptors) in AlGaAs/GaAs multiple-quantum-well structures. Calculations of these levels have been performed by a number of groups, most of which solved an effective-mass Schrödinger equation using the variational method. These results are generally consistent with each other, any differences being related to different approximations made in each calculation. The ground states of some of these shallow impurity levels have also been measured in several laboratories using low-temperature photoluminescence, Raman and far-infrared absorption techniques. These methods yield similar results which are consistent with the calculations. Both theoretical and experimental methods and results are discussed. 相似文献