Hybrid Catalyst Coupling Zn Single Atoms and CuNx Clusters for Synergetic Catalytic Reduction of CO2

Reverse water-gas shift (RWGS) reaction is the initial and necessary step of CO₂ hydrogenation to high value-added products, and regulating the selectivity of CO is still a fundamental challenge. In the present study, an efficient catalyst (CuZnN_x@C-N) composed by Zn single atoms and Cu clusters stabilized by nitrogen sites is reported. It contains saturated four-coordinate Zn-N₄ sites and low valence CuN_x clusters. Monodisperse Zn induces the aggregation of pyridinic N to form Zn-N₄ and N₄ structures, which show strong Lewis basicity and has strong adsorption for *CO₂ and *COOH intermediates, but weak adsorption for *CO, thus greatly improves the CO₂ conversion and CO selectivity. The catalyst calcined at 700 °C exhibits the highest CO₂ conversion of 43.6% under atmospheric pressure, which is 18.33 times of Cu-ZnO and close to the thermodynamic equilibrium conversion rate (49.9%) of CO₂. In the catalytic process, CuN_x not only adsorbs and activates H₂, but also cooperates with the adjacent Zn-N₄ and N₄ structures to jointly activate CO₂ molecules and further promotes the hydrogenation of CO₂. This synergistic mechanism will provide new insights for developing efficient hydrogenation catalysts.     

Adaptive fault-tolerant control for a class of flexible air-breathing hypersonic vehicles

In this paper, a novel adaptive fault-tolerant control (FTC) scheme is proposed for a class of flexible air-breathing hypersonic vehicles with unknown inertial and aerodynamic parameters and even input constraints. The fault model under consideration covers the case that all actuators suffer from unknown time-varying faults. In the controller design and stability analysis, we introduce new Lyapunov functions, some differentiable auxiliary functions, a bound estimation approach, and a Nussbaum function, which help us successfully circumvent the obstacle caused by the faults, input constraints, and flexible modes. In addition to higher reliability, the proposed scheme is able to ensure that all closed-loop signals are globally uniformly bounded and to steer the tracking errors of altitude and velocity into predefined arbitrarily small residual sets. As a result, the tracking accuracy can be designated in advance. Simulation results illustrate the effectiveness of the proposed scheme.     

人工智能技术在计算机网络技术中的应用

如今,人们的生活与计算机之间有着紧密的联系,计算机不仅可以实现对数据的处理,也可以朝着智能化和自动化的方向不断发展。在应用计算机的过程中,需要重视人工智能技术,结合时代的发展,提高技术的应用安全,促进企业长远、稳定地发展。另外,还需要注重人工智能技术在网络安全领域的应用,其可以保证整个计算机网络的应用效果,不断强化网络资源的共享性,让整个计算机网络为人类的持续发展提供良好的基础。     

基于深度学习的航拍光伏板红外图像热斑检测方法研究

针对光伏电站光伏板热斑故障难以检测的问题,结合无人机巡检技术,提出一种基于深度卷积神经网络的光伏板热斑快速检测方法。首先设计了光伏板识别模型,将Yolov4主干特征提取网络替换成轻量级网络MobileNetV2,并将PAnet网络中标准3×3卷积替换为深度可分离卷积,实现了将光伏板快速从红外图像中识别出来。为快速识别热斑并解决光伏板反光噪声问题,将MobileNetV2网络引入DeeplabV3+模型中,改进由于下采样造成的目标缺失,并将交叉熵损失函数修改为Dice损失函数来进一步提高分割精度。试验结果表明,该方法能够准确识别光伏板热斑,光伏板识别准确率为99. 56%,检测速度为22. 1帧/秒。光伏板识别后的热斑分割准确度达到95. 99%,交并比mIou达到85. 58,检测速度为24. 5帧/秒,该方法能够满足光伏板故障检测的需要。     

Testing Transverse Sensitivity of Linear Single-Axis Pendulous Accelerometer with Double Turntable Centrifuge

Current ISO standard methods for testing transverse sensitivity of accelerometers are vibration-based. They have difficulties in producing low-frequency vibration for various reasons. This paper introduces a double turntable centrifuge (DTC) to test the accelerometer transverse sensitivity at low frequencies (from 0.01 to 10 Hz). The proposed method can avoid limitations of traditional vibration-based schemes for transverse sensitivity test. In this paper, a theoretical analysis of the method is followed by a presentation of the experimental set-up, and the measurement procedure of a linear single-axis pendulous accelerometer. According to the theoretical analysis and experimental results, it is practicable to test the low-frequency transverse sensitivity with a DTC. The method proposed here can test accelerometer transverse sensitivity at low-frequency with large amplitudes (up to 700 m/s²), and directly measure the angle of the transverse sensitivity with high resolution. It can be a supplement to the standard methods for testing accelerometer transverse sensitivity at low-frequency.     

加强计量信息化建设,提高企业计量管理水平

网络化的计量管理信息系统在技术上的实用性和维护性上面都有其可靠性,对计量管理工作采用信息化管理可以真正实现完全意义上的信息共享,使我们管理的计量装置、计量器具准确可靠的运行。     

酞青钴-Fe_3O_4纳米复合粒子的化学稳定性研究

制备了酞菁钴（CoPc）－Fe3O4纳米复合粒子,研究了其化学稳定性．结果表明．CoPc与Fe3O4纳米粒子通过一定程度的化学键作用形成了有效的复合．在Fe3O4纳米粒子表面形成了包覆层,有效地保护其不被空气氧化。其抗氧化能力与CoPc包裹层的数目有很强的依赖关系。     

新一代液晶显示系统设计与实现

随着时代的演进和科技的进步,液晶显示已经在现代科技产品中得到广泛应用,为了提高液晶显示系统在带有电容触摸技术的现代电子产品中开发与应用,文章中采用新一代8位STM8S208系列MCU和ET-12864F液晶显示模块,设计了一种新型的液晶显示系统;同时介绍了STM8S208单片机的优越性和ET-12864F液晶显示模块的具体操作方法,并给出了单片机STM8S208与液晶显示模块ET-12864F构建的硬件接口电路和程序设计;经实践应用,该液晶显示系统应用开发成本低,效率高具有较好的项目应用参考价值。     

基于二阶梯度的图像增强算法研究

针对PCB图像的特点对图像进行增强处理,使得图像的边缘更加突出,灰度的对比度增加,同时滤除靠近边缘的噪声,为后续图像分割时更有效的选取阈值打下良好基础。使用二阶梯度算子获得图像的增强效果,实验表明,不仅解决了边缘附近噪声去除问题,而且有效地突出了边缘信息,图像的黑白对比分明,尤其是目标图像靠近边缘部分灰度值明显高于其他的非边缘区域。