排序方式: 共有15条查询结果,搜索用时 15 毫秒
1.
2.
3.
工作人员与变电站周界相互位置关系多变,监测与维护工作量大,针对系统干扰性较弱、误报率和漏报率较高、违章行为图像清晰度较低的问题,研究机器视觉的变电站数字化违章行为三维虚拟周界监测方法.在变电站作业区域安装激光器和摄像头,构建闭环区域,通过激光器预警作业人员违章行为,抓拍作业人员违章行为图像,经图像对比度增强、分割、匹配处理后,将静态违章行为图像变为三维动态图像,经卷积层的卷积处理,强化三维动态违章行为图像特征,通过子采样层、池化层、全连接层的特征降维、压缩、整合后,通过Softmax层识别作业人员违章行为,对作业人员实施违章行为周界监测.实验证明,周界探测装置具备灵敏度高、检测距离远、抗干扰性强、误报率和漏报率较低等优势,并数字化呈现监测结果,保护作业人员人身安全. 相似文献
4.
易拉罐形状和尺寸的最优设计 总被引:1,自引:0,他引:1
从用料最省的角度研究了易拉罐的形状和尺寸的优化设计问题,首先通过多次测量取平均值的方法得到了题目所需的数据.然后就问题二和问题三分别建立了优化模型,并借助数学软件进行了求解,得到了最优设计的尺寸.最后设计出了椭球形状的易拉罐作为自己的最优设计. 相似文献
5.
利用飞秒激光对ZnO晶体进行辐照,对辐照前后的晶体样品进行发光光谱及拉曼光谱检测.辐照后发光光谱的某些发光峰强度有明显增强,但未产生新的发光峰,表明没有新的缺陷结构产生,但晶体内锌空位、间隙位锌、间隙位缺陷浓度增加.拉曼光谱结果表明,辐照后ZnO晶体未产生相变,但随着辐照激光功率的增大,拉曼峰327 cm-1,437 cm-1强度明显减弱,表明在飞秒激光辐照作用下氧化锌的结晶程度下降.但574 cm-1峰值却随着辐照功率的增大而变大,分析表明该拉曼峰很可能是由于晶体内间隙位缺陷所致.同时实验过程中观察到飞秒激光倍频光产生. 相似文献
6.
经济的快速发展带动了我国网络计算机的快速发展,并且随着近些年的发展与成熟,人们已经越来越适应了网络化的社会生活.以电子商务为例,人们可以通过电子商务进行购物、娱乐、社交等.它的出现使人们的生活变得越来越轻松和方便,足不出户就可以购买世界各地的物品.
最早的网络惠及人们的是当时的E-mail,也就是电子邮件,它实现了人与人之间的即时交流,随后就是风靡中国的QQ,到现在的微信,越来越多的即时通讯软件出现了,到如今,人们之间的联系已经不仅仅是依靠电话和短信,而更多地依赖于语音和视频聊天.这也从侧面印证了人们对网络电子信息技术的依赖性越来越强. 相似文献
7.
8.
Physical analysis of normally-off ALD Al2O3/GaN MOSFET with different substrates using self-terminating thermal oxidation-assisted wet etching technique 下载免费PDF全文
Cheng-Yu Huang 《中国物理 B》2022,31(9):97401-097401
Based on the self-terminating thermal oxidation-assisted wet etching technique, two kinds of enhancement mode Al$_{2}$O$_{3}$/GaN MOSFETs (metal-oxide-semiconductor field-effect transistors) separately with sapphire substrate and Si substrate are prepared. It is found that the performance of sapphire substrate device is better than that of silicon substrate. Comparing these two devices, the maximum drain current of sapphire substrate device (401 mA/mm) is 1.76 times that of silicon substrate device (228 mA/mm), and the field-effect mobility ($\mu_{\rm FEmax}$) of sapphire substrate device (176 cm$^{2}$/V$\cdot$s) is 1.83 times that of silicon substrate device (96 cm$^{2}$/V$\cdot$s). The conductive resistance of silicon substrate device is 21.2 $\Omega {\cdot }$mm, while that of sapphire substrate device is only 15.2 $\Omega {\cdot }$mm, which is 61% that of silicon substrate device. The significant difference in performance between sapphire substrate and Si substrate is related to the differences in interface and border trap near Al$_{2}$O$_{3}$/GaN interface. Experimental studies show that (i) interface/border trap density in the sapphire substrate device is one order of magnitude lower than in the Si substrate device, (ii) Both the border traps in Al$_{2}$O$_{3}$ dielectric near Al$_{2}$O$_{3}$/GaN and the interface traps in Al$_{2}$O$_{3}$/GaN interface have a significantly effect on device channel mobility, and (iii) the properties of gallium nitride materials on different substrates are different due to wet etching. The research results in this work provide a reference for further optimizing the performances of silicon substrate devices. 相似文献
9.
We report on the fabrication of two kinds of large core arca Nd^3 doped sillcate glass photonic crystal fibres and demonstration of the fibre waveguiding properties the measured minimum loss of one kind of fibres is 2。5db/m at 660 nm.The fibres sustain only a single mode at least over the wavelength range from 660nm to 980 nm. 相似文献
10.