期刊文献+
共找到4篇文章
< 1 >
每页显示 20 50 100
Nucleophilic imidoesterification of dicarbonyl compounds with cyanatobenzenes through C-C bond formation 被引量:2
1
作者 Hang Ma Yang He +7 位作者 Ruo-Feng Huang Xiao-Hui Zhang Jing Pan Jia-Qiang Li Chao He Xue-Ge Ling xuan-lun Wang Yan Xiong 《Chinese Chemical Letters》 SCIE CAS CSCD 2014年第10期1327-1330,共4页
Under neat conditions,an efficient method for synthesis of imidoesters has been developed using cyanatobenzenes and dicarbonyl compounds.Nucleophilic addition spontaneously occurred between the two kinds of materials ... Under neat conditions,an efficient method for synthesis of imidoesters has been developed using cyanatobenzenes and dicarbonyl compounds.Nucleophilic addition spontaneously occurred between the two kinds of materials at room temperature with yields of up to 90%.A mechanism directed towards to the imidoester formation has been proposed. 展开更多
关键词 Imidoesters Cyanatobenzenes Dicarbonyl compounds Imidoesterification Nucleophilic addition
原文传递
Reconstruction of quantum channel via convex optimization 被引量:2
2
作者 xuan-lun Huang Jun Gao +6 位作者 Zhi-Qiang Jiao Zeng-Quan Yan Zhe-Yong Zhang Dan-Yang Chen Xi Zhang Ling Ji Xian-Min Jin 《Science Bulletin》 SCIE EI CAS CSCD 2020年第4期286-292,共7页
Quantum process tomography is often used to completely characterize an unknown quantum process.However, it may lead to an unphysical process matrix, which will cause the loss of information with respect to the tomogra... Quantum process tomography is often used to completely characterize an unknown quantum process.However, it may lead to an unphysical process matrix, which will cause the loss of information with respect to the tomography result. Convex optimization, widely used in machine learning, is able to generate a global optimum that best fits the raw data while keeping the process tomography in a legitimate region. Only by correctly revealing the original action of the process can we seek deeper into its properties like its phase transition and its Hamiltonian. Here, we reconstruct the seawater channel using convex optimization and further test it on the seven fundamental gates. We compare our method to the standard-inversion and norm-optimization approaches using the cost function value and our proposed state deviation. The advantages convince that our method enables a more precise and robust estimation of the elements of the process matrix with less demands on preliminary resources. In addition, we examine on a set of non-unitary channels and the reconstructions reach up to 99:5% accuracy. Our method offers a more universal tool for further analyses on the components of the quantum channels and we believe that the crossover between quantum process tomography and convex optimization may help us move forward to machine learning of quantum channels. 展开更多
关键词 QUANTUM INFORMATION QUANTUM process TOMOGRAPHY CONVEX optimization QUANTUM CHANNEL
原文传递
基于RSEI模型的贡山县生态质量动态监测及影响因素分析 被引量:1
3
作者 蒋文学 李益敏 +2 位作者 杨雪 邓选伦 刘师旖 《西北师范大学学报(自然科学版)》 CAS 北大核心 2023年第5期106-115,共10页
在碳中和及生态文明建设背景下,生态环境质量得到高度关注.利用遥感技术可以快速、实时获取全面的地表综合信息以及评价生态环境质量,为区域生态环境治理、改善以及未来规划提供参考.文中选取怒江州贡山县2004年Landsat 5 TM影像和2013... 在碳中和及生态文明建设背景下,生态环境质量得到高度关注.利用遥感技术可以快速、实时获取全面的地表综合信息以及评价生态环境质量,为区域生态环境治理、改善以及未来规划提供参考.文中选取怒江州贡山县2004年Landsat 5 TM影像和2013、2020年Landsat 8 OLI影像构建遥感生态指数(RSEI)模型,对贡山县2004—2020年的生态状况及变化趋势进行监测与评价分析.结果表明,2004、2013、2020年研究区RSEI值分别为0.73,0.75,0.69,呈先上升再下降趋势,生态环境质量整体下降;2004—2020年期间研究区大部分地区生态环境质量变异程度非常稳定,面积占比为87.37%,仅独龙江乡和捧当乡少部分地区变异程度相对较高,面积占比为2.04%;影响贡山县RSEI变化的主要因素是人口、国内生产总值和建筑面积,表明贡山县生态环境质量变化与快速增长的人口和人类活动干扰有关;预测到2025年RSEI值较2020年有所上升,但幅度较小,在未来生态环境治理中仍应进行持续的保护与治理. 展开更多
关键词 生态环境质量 遥感生态指数 主成分分析 影响因素 贡山县
下载PDF
医药输液灯检机对产品异物准确检测仿真
4
作者 张辉 李宣伦 《计算机仿真》 北大核心 2019年第2期330-335,共6页
针对250 mL及以上医药大输液生产过程中造成药液中出现毛发、漂浮物、玻璃屑等可见异物的在线实时检测难题,开发了一种基于分层联合稀疏表示的医药输液全自动智能灯检机。首先通过改进的分块主成分追踪算法对序列图像中的运动目标进行... 针对250 mL及以上医药大输液生产过程中造成药液中出现毛发、漂浮物、玻璃屑等可见异物的在线实时检测难题,开发了一种基于分层联合稀疏表示的医药输液全自动智能灯检机。首先通过改进的分块主成分追踪算法对序列图像中的运动目标进行检测以排除静止背景噪声干扰,然后利用稀疏矩阵分块聚类算法得到运动目标的运动轨迹并提取运动轨迹的空间特征向量,最后为了提高传统稀疏表示分类器对异物识别的能力,提出分层联合稀疏表示分类器根据运动轨迹的空间特征向量对异物进行识别,以排除随机噪声的干扰。仿真结果证明,该系统克服了检测过程中各种噪声干扰对异物识别的影响,解决了医药大输液可见异物的在线实时检测难题。 展开更多
关键词 异物检测 分块主成分追踪 稀疏矩阵分块聚类 轨迹空间特征向量 分层联合稀疏表示
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部