Recrystallization behavior,oxygen vacancy and photoluminescence performance of sputter-deposited Ga2O3 films via high-vacuum in situ annealing

Ga₂O₃ films were deposited on Si substrates through radio-frequency magnetron sputtering at room temperature and were annealed in situ in a high-vacuum environment. The as-deposited Ga₂O₃ film exhibited an island-like surface morphology and had an amorphous microstructure, with a few nanocrystalline grains embedded in it. After high-temperature in situ annealing, the films recrystallized and exhibited coalesced surfaces. Because of the thermally driven diffusion of Ga, the interfacial layer between Si and Ga₂O₃ was composed of SiGaO_x. Compared with ex situ annealing in air, in situ annealing in high vacuum is more advantageous because it enhances surface mobility and improves the crystallinity of the Ga₂O₃ films. The higher oxygen vacancy concentration of in situ annealed films revealed that oxygen atoms were easily released from the Ga₂O₃ lattice during high-vacuum annealing. Photoluminescence (PL) spectra exhibited four emission peaks centered in ultraviolet, blue, and green regions, and the peak intensities were significantly enhanced by thermal annealing at >600 °C. This work elucidates the effect of the in situ annealing treatment on the recrystallization behavior, interfacial microstructure, oxygen vacancy concentration, and PL performance of the Ga₂O₃ films, making it significant and instructional for the further development of Ga₂O₃-based devices.     

工业机器人在自动化生产线分拣站的应用

根据自动化生产线分拣站的工艺流程和自动化控制的要求,提出基于工业机器人、PLC以及传送带的货物码垛自动化解决方案。构建以三菱FX3U型PLC、传送带和工业机器人等组成的全自动分拣码垛系统。分析了PLC的动作过程,提供了PLC的程序流程图;分析了工业机器人码垛的工作过程,提供了工业机器人码垛的程序流程图。工业机器人引入到自动化生产系统后,能够进一步提高工厂自动化水平、提高生产效率,减小劳动强度,降低人工成本。     

Nonthermal plasma (NTP) activated metal–organic frameworks (MOFs) catalyst for catalytic CO2 hydrogenation

A systematic study of Ni supported on metal–organic frameworks (MOFs) catalyst (i.e., 15Ni/UiO-66) for catalytic CO₂ hydrogenation under nonthermal plasma (NTP) conditions was presented. The catalyst outperformed other catalysts based on conventional supports such as ZrO₂, representing highest CO₂ conversion and CH₄ selectivity at about 85 and 99%, respectively. We found that the turnover frequency of the NTP catalysis system (1.8 ± 0.02 s⁻¹) has a nearly two-fold improvement compared with the thermal catalysis (1.0 ± 0.06 s⁻¹). After 20 hr test, XPS and HRTEM characterizations confirmed the stability of the 15Ni/UiO-66 catalyst in the NTP-activated catalysis. The activation barrier for the NTP-activated catalysis was calculated as ~32 kJ mol⁻¹, being lower than the activation energy of the thermal catalysis (~70 kJ mol⁻¹). In situ DRIFTS characterization confirmed the formation of multiple carbonates and formates on catalyst surface activated by NTP, surpassing the control catalysts (e.g., 15Ni/α-Al₂O₃ and 15Ni/ZrO₂).     

Anomalous thermal expansion behavior in Er1-xCaxMnO3

Perovskite Er_1-xCa_xMnO₃ (x = 0, 0.1, 0.2, 0.25, 0.3, 0.4, 0.5) was synthesized using a solid-state method. Thermal expansion behavior was tested using a thermal dilatometer and high-temperature X-ray diffraction (XRD). The experimental results indicated the doping contents of Ca (x) in the Er_1-xCa_xMnO₃ have a dramatic effect on their thermal expansion behavior. The samples of Er_1-xCa_xMnO₃ (x = 0.1,0.2 and 0.25) exhibit positive thermal expansion (PTE) characteristics while Er_0.7Ca_0.3MnO₃ (x = 0.3) exhibits a negative thermal expansion (NTE) property with a thermal expansion coefficient of −3.1 × 10⁻⁶ K⁻¹ in room temperature (RT) −750 K. In addition, Er_0.6Ca_0.4MnO₃ (x = 0.4) exhibits NTE properties only at RT–500 K, and Er_0.5Ca_0.5MnO₃ (x = 0.5) exhibits PTE properties at RT–750 K. The thermal shrinkage mechanism is the Jahn–Teller effect of the Mn³⁺ ions and the double exchange of Mn³⁺–O–Mn⁴⁺ in Er_0.7Ca_0.3MnO₃. This phenomenon causes Mn–O octahedral distortion and oxygen vacancy, causing Er_0.7Ca_0.3MnO₃ to become anisotropic. This feature results in the elastic deformation of Er_0.7Ca_0.3MnO₃ during heating, which consumes the void and displays NTE at macro level.     

Quantum effect of cooling down the environment temperature of mesoscopic LC circuit

We examine the quantum effect of cooling down the environment temperature of mesoscopic LC circuit, and find that the ground state of the circuit is no longer in the thermo vacuum state, but in a negative binomial state. We calculate energy of the circuit in this new state, which increases with the cooling of the environment.     

马铃薯渣综合利用研究现状及进展

马铃薯渣是马铃薯淀粉加工产业的一种副产物,常被作为垃圾废弃掉,造成资源浪费和环境污染。实际上,马铃薯渣中含有许多有价值的成分,具有被开发利用的潜力。目前,马铃薯渣的综合利用主要集中在以下几方面:提取膳食纤维和果胶;制备高蛋白高能量饲料;制备新型黏合剂、胶黏剂和吸附材料;制备燃料酒精、生物质混合燃料和能量气体;制备种曲、醋、酱油及可食性膜等。综述了马铃薯渣目前综合利用的研究现状及进展。     

The influences of system usability and user satisfaction on continued Internet banking services usage intention: empirical evidence from Taiwan

This study proposes an extended technology acceptance model to investigate the effects of system usability and satisfaction on users’ intention to continue using Internet banking services. Based on a survey data from 304 respondents, structural equation modeling technique was employed to validate the model. The empirical results found that users’ continuance usage intention is jointly determined by perceived usefulness, perceived compatibility and satisfaction level. The hypothesized model explains 48.2 % of the variance in continuous usage intention. Results of multi-group analysis reveal that there are different concerns and priorities between skilled and less skilled users. Given that the sample of this study is collected from a particular industry in Taiwan, the generalizability of the findings may be limited. However, the comprehensiveness and representativeness of the research sample is a major strength of this study.     

粉煤灰-人工复合生态系统一体化处理酸性含铬废水的工艺研究

重金属铬对人类的影响不仅仅只是自身,还会影响以后的一代人甚至是几代人。文章在遵循以废治废及可持续发展的绿色环保理念的前提下,通过粉煤灰净水法与人工复合生态系统净水法的有机结合,使电镀铬废水达标排放。     

真三轴条件下的岩石细观损伤力学模型

本文提出了真三轴条件下的岩石细观损伤力学模型，建立了岩石的损伤演化方程，给出了损伤柔度的求解公式。数值分析表明中主应力对岩石应力－应变关系有明显的影响，一般表现为随中主应力的增加，最大主应力方向的变形减小，最小主应力方向的变形增大；但当最大主应力很大时，大的中主应力反而使最大主应力方向的变形增加，最小主应力方向的变形减小。     

实践论对技术类专业知行的适用——以建筑学专业为例

《实践论》是被极其成功的实践反复证实的哲学，其基本思想广泛适用于实践活动过程。技术类专业有着各种实践教学过程，是学生认知中常见的基本活动，学生通过实践训练实现从感性认识到理性认识的飞跃；学生毕业后用所学知识反实践于社会，完成认知的第二次飞跃。实践论对学习和工作中出现的若干问题与困扰的解决具有很好的指导意义。