井下高压电网智能化综合保护系统的研究

在分析电网漏电故障规律的基础上,设计了一种适于不同中性点接地方式的电网的新型智能化综合保护系统。本文重点分析保护系统的原理,并介绍了硬件结构和软件框图。该保护系统经试验运行性能稳定,运行可靠,具有推广价值。     

利用界面分析仪实现浓缩机自动控制

介绍了界面分析仪的原理以及在选煤浓缩机检测方面的应用，设计了一套浓缩机自动控制系统。     

液晶投影电视中视频信号与显示模件接口电路的设计与研究

本文介绍了液晶投影电视的基本原理和光学系统,根据液晶显示模件的接口参数,设计了液晶投影电视的接口电路,对该电路的工作原理进行了分析和讨论。同时,对行同步相位调整电路进行了详细的电路设计和研究。     

无人机地面测控软件

为满足对无人机飞行的实时监控以及后期数据处理分析的需要,并能给予地面测控人员更真实的飞行控制直观感受,开发一种基于中央操纵杆的无人机地面测控软件。基于VC++,结合实际物理设备,分析该软件的总体结构设计,介绍地面测控软件的人机界面,给出地面测控软件的遥控遥测模块功能的设计与实现,并进行无人机地面仿真试验。仿真试验结果表明:该软件正确合理,满足设计要求,已用于实际无人机飞行项目中。     

中国大陆科学钻探钻探子工程钻进实时记录网页的开发

以中国大陆科学钻探实时记录网页的开发为例,介绍了在开发网络数据库时,利用Excel组件作输入界面,实现查询界面上表格的表头和表尾不动、而中间行可以滚动,实现回次滚动查询和界面实时刷新.     

硫化矿细菌浸出的半导体能带理论分析

许多硫化矿物为半导体 ,硫化矿氧化浸出过程实际是一半导体 溶液界面电子或空穴转移的过程。基于传统的半导体界面氧化理论 ,系统分析细菌存在时硫化矿 溶液界面电子或空穴转移步骤 ,提出黄铁矿、黄铜矿、铜兰细菌浸出过程的半导体 溶液界面电子及空穴转移模型 ,从半导体能带理论角度揭示了硫化矿细菌氧化浸出机理     

载荷对含Cr碳膜摩擦磨损性能影响研究

用闭合场非平衡磁控溅射技术制备了高硬度含Cr碳膜。分别用压入法和划痕法测定了薄膜的结合强度。薄膜厚度用球坑法表征。用显微硬度计测定了薄膜的努氏硬度。在不同载荷条件下,用Ball-on-disc球盘磨损试验机研究了薄膜的摩擦系数、比磨损率的变化规律。分析讨论了载荷对含Cr碳膜摩擦磨损性能的影响。结果发现：随着载荷的提高,对磨钢球时薄膜的摩擦系数呈下降趋势．对磨损轨迹和对磨球磨损表面的扫描电镜（SEM）观察发现存在转移膜现象。对磨球磨损表面的EDX分析结果进一步证明了转移膜的存在。文中还对含Cr碳膜磨损机理进行了分析和讨论。用闭合场非平衡磁控溅射技术制备了高硬度含Cr碳膜。分别用压入法和划痕法测定了薄膜的结合强度。薄膜厚度用球坑法表征。用显微硬度计测定了薄膜的努氏硬度。在不同载荷条件下,用Ball-on-disc球盘磨损试验机研究了薄膜的摩擦系数、比磨损率的变化规律。分析讨论了载荷对含Cr碳膜摩擦磨损性能的影响。结果发现：随着载荷的提高,对磨钢球时薄膜的摩擦系数呈下降趋势．对磨损轨迹和对磨球磨损表面的扫描电镜（SEM）观察发现存在转移膜现象。对磨球磨损表面的EDX分析结果进一步证明了转移膜的存在。文中还对含Cr碳膜磨损机理进行了分析和讨论。     

On estimating the interface normal and curvature in piecewise linear interface calculation-volume of fluid approach for three-dimensional arbitrary meshes

Volume of fluid (VOF) method with its Piecewise Linear Interface Calculation (PLIC) reconstruction algorithm is one of the most popular approaches in numerical simulation of interfacial flows with a wide range of applications in different areas. In an effort to evaluate the similarity of the PLIC-generated planes in comparison with the exact interface, a point-cloud, based on the polygon centers of PLIC planes is extracted, which later is used to form a triangular grid that represents the estimated interface. The main objective of this article is to evaluate the interface geometrical properties based on the extracted triangular grid of the interface. The methods presented in this article, characterized by a higher spatially convergence ratio, are compared with the commonly used methods. The proposed methods are tested for two 3-dimensional general test cases, where an evident improvement is seen in calculation accuracy and spatial convergence of the errors of interface normal vector and curvature.     

Insight into the selective oxidation mechanism of glycerol to 1,3-dihydroxyacetone over AuCu–ZnO interface

Directional regulation of polyol oxidation selectivity by constructing active sites with specific structure is a critical yet challenging problem. Herein, the specific Au-based catalyst with efficient Au–Cu–ZnO interfacial active sites was successfully designed to promote selective oxidation of glycerol to 1,3-dihydroxyacetone under mild conditions. X-ray absorption spectroscopy revealed that the increased electron transfer between Au and Cu increases the content of Au⁺, resulting in the higher catalytic activity (turnover frequency: 402.5 h⁻¹). Meanwhile, small AuCu alloy nanoparticles (ca., 2.7 nm) could be inserted into the ZnO lattice with the formation of Au(Cu)–O–Zn linkages, resulting in the enrichment of interfacial oxygen vacancies. These interfacial oxygen vacancies induce the activation and adsorption of the secondary hydroxyl group of glycerol on the interfacial active sites, improving the selectivity of 1,3-dihydroxyacetone (83.4%). Furthermore, in situ Fourier transform infrared, structure-dependent kinetics and density functional theory calculation demonstrated that Au–Cu–ZnO interfacial active sites could enhance the participation of OH* and oxygen vacancies in activating the O H and C H bonds, respectively, promoting the improvement of the catalytic performance. The outcome of this work offers new insights for the rational design of high effective catalyst for the selective oxidation of polyol.     

BFRP筋与分级粒径河砂ECC粘结滑移性能试验研究

通过玄武岩纤维增强复合材料(BFRP)筋/高延性水泥基复合材料(ECC)的中心拉拔试验,分析了分级粒径ECC和BFRP筋表面形式及直径对BFRP筋/ECC粘结性能及粘结-滑移曲线的影响。结果表明,BFRP筋/ECC的破坏模式分为BFRP筋拔出破坏和BFRP筋拉伸破坏。选取BFRP筋/ECC粘结-滑移曲线中的残余波浪段各峰值应力点,采用拟合直线斜率的绝对值|k|表征ECC对BFRP筋横肋的磨损程度,当|k|值≥0.144时,BFRP筋横肋会被完全磨损,当|k|值＜0.144时,BFRP筋横肋会被磨损至与填充其凹陷的ECC齐平。BFRP筋/ECC的平均粘结强度随骨料粒径的变化并不显著,分级粒径ECC可使BFRP筋/ECC的平均粘结强度提高3.2%~9.6%,采用骨料粒径为0.15~0.3 mm的BFRP筋/ECC粘结性能最优。BFRP筋的直径越大,BFRP筋/ECC的平均粘结强度越小,BFRP筋直径为12 mm的BFRP筋/ECC平均粘结强度与BFRP筋直径为8 mm、10 mm的BFRP筋/ECC相比降低分别约8.2%、4.4%。采用浅螺纹BFRP筋的BFRP筋/ECC,平均粘结强度下降83.7%,但其整体粘结应力变化较为平稳,对ECC和BFRP筋的损伤程度均最小。减小BFRP筋直径、ECC骨料粒径,或BFRP筋/ECC自由端处BFRP筋的肋深,有助于提高BFRP筋/ECC的粘结性能及稳定性。