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基于单元级损伤指标的纤维增强复合材料层合板损伤识别方法

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复合材料学报 2024年第3期41卷 1539-1553页

作者：石庆贺杨颖孙伟王昊胡可军江苏理工学院材料工程学院常州213001 中国航空研究院北京100000

本文针对复合材料层合板结构提出了一种能够综合反映其承载能力缺失的单元级损伤指标-层合单元损伤指标,该指标既可以反映层合板面内外方向刚度的损伤情况,又具有参数数量较少、较易识别的优点。为保证所提损伤指标的合理性,本文利用数... 详细信息

本文针对复合材料层合板结构提出了一种能够综合反映其承载能力缺失的单元级损伤指标-层合单元损伤指标,该指标既可以反映层合板面内外方向刚度的损伤情况,又具有参数数量较少、较易识别的优点。为保证所提损伤指标的合理性,本文利用数学和力学算子对单元级损伤指标与材料级损伤指标进行了等效,并比较了不同损伤指标在表征损伤程度之间的差异性。并提出了基于单元级损伤参数的复合材料结构损伤识别流程,即首先利用单元应变能差值指标对损伤单元进行筛选,然后利用优化方法对候选单元的损伤程度进行辨识。本文所提方法通过数值算例和一个试验进行了验证,分析了单元级损伤参数各个元素之间的相关性,并验证了基于单元级损伤参数的复合材料层合板结构损伤识别流程。本文的研究成果补充了现有复合材料结构健康监测理论。

关键词：复合材料损伤识别单元级损伤参数层合板结构优化损伤定位

基于记忆多项式的Volterra混合均衡器设计与研究

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光通信研究 2024年第3期 36-44页

作者：贾科军雷蕾蔺莹余彩虹兰州理工大学计算机与通信学院兰州730050 福建工程学院电子电气与物理学院福州366000

【目的】发光二极管(LED)的非线性特性导致可见光通信(VLC)系统的误码率(BER)性能恶化,特别是在具有较高峰均功率比(PAPR)的光正交频分复用(O⁃OFDM)系统中。基于Volterra级数的单级均衡器可以处理LED非线性高阶失真,且延时较小。但是求... 详细信息

【目的】发光二极管(LED)的非线性特性导致可见光通信(VLC)系统的误码率(BER)性能恶化,特别是在具有较高峰均功率比(PAPR)的光正交频分复用(O⁃OFDM)系统中。基于Volterra级数的单级均衡器可以处理LED非线性高阶失真,且延时较小。但是求解传统Volterra级数需要多重积分运算,基于Volterra级数的均衡器实现复杂度高,且单级均衡器存在误差累积,因此均衡抑制效果有限。【方法】首先,针对传统Volterra级数计算复杂度高的问题,只保留Volterra级数中各阶非线性项和内核系数的高阶幂级数项,提出了基于记忆多项式的Volterra级数(MPVS)。相比于传统Volterra级数降低了计算复杂度,同时考虑了当前时刻的所有输入信号,提高了非线性系统建模的精度。然后,设计基于记忆多项式的Volterra(MPV)均衡器和基于记忆多项式的Volterra判决反馈均衡器(MPV⁃DFE),对于单级MPV⁃DFE,若判决部分一个码元判断错误,那么这种错误会连续成串出现,导致整个码元序列受到影响。文章提出将MPV和MPV⁃DFE两个非线性均衡器级联构成混合后均衡器(MPV+MPV⁃DFE)。MPV均衡器对LED非线性失真信号一级均衡,可以抑制一部分非线性失真,从而减少MPV⁃DFE码元判断错误。再经过MPV⁃DFE二次均衡,可以更好地抑制残留的非线性失真。【结果】最后,采用蒙特卡洛BER仿真方法验证系统设计的有效性。结果表明:与单级MPV均衡器、线性级联非线性混合均衡器(LMS+MPV-DFE)相比,在4阶正交幅度调制(QAM)非对称限幅光OFDM(ACO⁃OFDM)系统BER为10^(-4)时,所提混合均衡器分别可以获得大约7和2 dB的信噪比增益。【结论】MPV均衡器实现简单,且将两级非线性均衡器级联设计混合均衡器可以更好地抑制LED非线性失真。

关键词：可见光通信发光二极管非线性沃尔泰拉级数混合后均衡器

针刺四关穴缓解无痛胃镜诊疗术中并发呃逆疗效观察

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上海针灸杂志 2024年第6期43卷 599-603页

作者：钟玉婷田克钧李盈赖露明赣南医学院第一附属医院赣州341000

目的基于“气逆动膈”理论,观察针刺四关穴缓解无痛胃镜诊疗术中并发呃逆的有效性和安全性。方法将100例无痛胃镜诊疗术中并发呃逆的患者随机分为治疗组和对照组,每组50例。治疗组采用针刺双侧合谷、太冲穴治疗,对照组不做任何治疗。... 详细信息

目的基于“气逆动膈”理论,观察针刺四关穴缓解无痛胃镜诊疗术中并发呃逆的有效性和安全性。方法将100例无痛胃镜诊疗术中并发呃逆的患者随机分为治疗组和对照组,每组50例。治疗组采用针刺双侧合谷、太冲穴治疗,对照组不做任何治疗。观察并记录两组呃逆持续时间、胃镜治疗时间、麻醉苏醒时间及不同时间点各项血流动力学指标[平均动脉压(mean arterial pressure, MAP)、心率(heart rate, HR)、血氧饱和度(oxygen saturation, SPO_(2))],比较两组临床疗效。结果治疗组治疗后治愈率和总有效率分别为50.0%和82.0%,明显高于对照组的14.0%和48.0%,两组比较差异均具有统计学意义(P<0.05)。治疗组呃逆持续时间、胃镜治疗时间均明显少于对照组(P<0.05)。两组呃逆开始时SPO_(2)水平均较基础值显著下降(P<0.05)。治疗组施针后5 min和10 min SPO_(2)水平均明显高于对照组,两组比较差异均具有统计学意义(P<0.05)。结论针刺四关穴治疗无痛胃镜诊疗术中并发呃逆疗效确切,能有效减少患者呃逆持续时间和胃镜治疗时间。

关键词：针刺疗法呃逆穴,合谷穴,太冲手术后并发症胃镜

Dynamic changes of genomic methylation profiles at different growth stages in Chinese Tan sheep

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Journal of Animal Science and Biotechnology 2022年第1期13卷 82-93页

作者： Yufang Liu Qiao Xu Xiaolong Kang kejun Wang Jve Wang Dengzhen Feng ying Bai Meiying Fang Department of Animal Genetics and Breeding National Engineering Laboratory for Animal BreedingMOA Laboratory of Animal Genetics and BreedingCollege of Animal Science and TechnologyChina Agricultural UniversityNo.2 Yuanmingyuan West RdBeijing 100193People’s Republic of China College of Life Sciences and Food Engineering Hebei University of EngineeringHandan 056021People’s Republic of China Biotechnology Institute Nanchang Normal UniversityNanchang 330029People’s Republic of China College of Agriculture Ningxia UniversityYinchuan 750021People’s Republic of China College of Animal Science and Veterinary Medicine Henan Agricultural UniversityZhengzhou 450002People’s Republic of China Beijing Key Laboratory for Animal Genetic Improvement Beijing 100193People’s Republic of China

Background:Tan sheep,an important local sheep breed in China,is famous for their fur quality.One-month-old Tan sheep have white,curly hair with beautiful flower spikes,commonly known as“nine bends”,which has high economic value.However,the“nine bends”characteristic gradually disappears with age;consequently,the economic value of the Tan sheep decreases.Age-related changes in DNA methylation have been reported and may be responsible for age-induced changes in gene expression.Until now,no genome-wide surveys have been conducted to identify potential DNA methylation sites involved in different sheep growth stages.In this study we investigated the dynamic changes of genome-wide DNA methylation profiles in Tan sheep using DNA from skin and deep whole-genome bisulfite sequencing,and compared the DNA methylation levels at three different growth stages:1,24,and 48 months old(mon1,mon24,and mon48,respectively).Results:In this study,11 skin samples from three growth stages(four for mon1,four for mon24,and three for mon48)were used for DNA methylation analysis and gene expression profiling.There were 52,288 and 236 differentially methylated genes(DMGs)identified between mon1 and mon24,mon1 and mon48,and mon24 and mon48,respectively.Of the differentially methylated regions,1.11%,7.61%,and 7.65% were in the promoter in mon1 vs.mon24,mon24 vs.mon48,and mon1 vs.mon48,respectively.DMGs were enriched in the MAPK and WNT signaling pathways,which are related to age growth and hair follicle morphogenesis processes.There were 51 DMGs associated with age growth and curly fleece formation.Four DMGs between mon1 and mon48(KRT71,CD44,ROR2 and ZDHHC13)were further validated by bisulfite sequencing.Conclusions:This study revealed dynamic changes in the genomic methylation profiles of mon1,mon24,and mon48 sheep,and the percentages of methylated cytosines were 3.38%,2.85% and 4.17%,respectively.Of the DMGs,KRT71 and CD44 were highly methylated in mon1,and ROR2 and ZDHHC13 were highly methylated in mon48.These findings provide foundational in

关键词： Chinese tan sheep Different growth stages DNA methylation Whole genome bisulfite sequencing

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基于腕力传感器的机器人位置触觉

机器人 1997年第4期19卷 265-270页

作者：周学才李泽湘张启先广东工业大学电工系香港科技大学北京航空航天大学

作为对常规位置触觉的一种替代，本文展示了在机器人手指尖的根部安装腕力传感器，并利用其测量数据来确定上述位置信息的方法．文中提出了一种带有重力效应补偿的数学模型，并对其解的唯一性和精度进行了论证和分析．最后，还给出了一... 详细信息

作为对常规位置触觉的一种替代，本文展示了在机器人手指尖的根部安装腕力传感器，并利用其测量数据来确定上述位置信息的方法．文中提出了一种带有重力效应补偿的数学模型，并对其解的唯一性和精度进行了论证和分析．最后，还给出了一个采用美国产ＬｏｒｄＦＴ３３５ｘ腕力传感器作为位置触觉的实验结果．

关键词：机器人腕力传感器触觉多指手

The initial exploration for ^(26)Al chronology in deep-sea ferromanganese crust

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辐射探测技术与方法(英文) 2023年第2期7卷 297-303页

作者： kejun Dong ying Hu Lifeng Cui Jiaqi Zhang Sheng Xu Hongtao Shen School of Earth System Science Tianjin UniversityTianjin300072China Guangxi Key Laboratory of Nuclear Physics and Technology Guangxi Normal UniversityGuilin541004China

Background The deep-sea ferromanganese crust(DSFC)is a natural archive for recording the history of the Earth’s evolution,as one of the most common authigenic assemblages in marine sediments.Although the depositional age dating using meteoric ^(10)Be has been successfully used in the study on the chronology of DSFC,the research on ^(26)Al has not seen relevant reports in this aspect due to the influence of factors such as measurement sensitivity and ^(26)Al in situ production.Method The first exploration for ^(26)Al chronology in DSFC was carried out by using accelerator mass spectrometry(AMS)measurements of ^(10)Be and ^(26)Al,and the comparison of relationship between isotopic ratios and concentrations of Al and Be.Results The growth rates of G.R=(1.44±0.09)mm/Ma,(3.58±0.29)mm/Ma,(1.52±0.10)mm/Ma and(2.93±0.14)mm/Ma are derived using ^(10)Be/^(9)Be,^(26)Al/^(27)Al ratios,^(10)Be and ^(26)Al concentrations,respectively.Conclusion The ^(26)Al chronological methods have been explored based on a DSFC sample and encouraging results were obtained.The results are preliminary and insufficient;some information is still needed to explain the difference between ^(26)Al and ^(10)Be chronology.

关键词： Deep-sea ferromanganese crust Accelerator mass spectrometry ^(10)Be ^(26)Al Dating

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五结合一回归教学模式在中医诊断学中的应用

中国中医药现代远程教育 2024年第1期22卷 1-3页

作者：王科军刘莹曲骞毕殿勇于晓飞滨州医学院中西医结合学院山东烟台264000

依据中医诊断学课程特点,对接新时代中医药高等教育要求,课程组积极构建“五结合一回归”教学模式,将理论教学与实践教学相结合,线下教学与线上教学相结合,第一课堂与第二课堂相结合,课程思政与思政课程相结合,过程性与终结性考核相结合... 详细信息

依据中医诊断学课程特点,对接新时代中医药高等教育要求,课程组积极构建“五结合一回归”教学模式,将理论教学与实践教学相结合,线下教学与线上教学相结合,第一课堂与第二课堂相结合,课程思政与思政课程相结合,过程性与终结性考核相结合,授课回归中医经典,强化中医思维培养,实现了知识、能力、素质、情感态度与价值的融合式发展,为中医药传承创新人才培养提供了新思路。

关键词：五结合一回归中医诊断学

^(18)F-FDG PET/CT显像步进采集与连续进床采集模式图像质量分析研究

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中国医学计算机成像杂志 2021年第4期27卷 358-363页

作者：杨波刘春利温德媛刘璐石华铮张江峰曹建峰苏芸朱毕华应坷均浙江省龙游县人民医院放射科上海市全景云医学影像诊断中心

目的:探讨^(18)F-脱氧葡萄糖(FDG)PET/CT显像连续进床(CBM)和步进(SS)采集模式对图像质量的影响。方法:受检者按1∶1随机分组(每组各50例),分别采用CBM和SS图像采集模式进行^(18)F-FDG PET/CT成像,比较两者成像时间和图像质量的差异。采... 详细信息

目的:探讨^(18)F-脱氧葡萄糖(FDG)PET/CT显像连续进床(CBM)和步进(SS)采集模式对图像质量的影响。方法:受检者按1∶1随机分组(每组各50例),分别采用CBM和SS图像采集模式进行^(18)F-FDG PET/CT成像,比较两者成像时间和图像质量的差异。采用t检验、Mann-Whitney U检验及χ^(2)检验比较相关差异的统计学意义。结果:CBM组和SS组受检者年龄、男/女构成差异均无统计学意义。CBM组图像采集时间明显短于SS组[444(21)s比710(102)s,Z=-8.733,P0.05)。结论:通过设定个体化的连续进床速率,CBM采集模式可以实现在不影响图像质量的前提下明显缩短图像采集时间,提高临床检查效率。

关键词：正电子发射断层显像术计算机体层成像术图像处理,计算机辅助移动脱氧葡萄糖

Vision, application scenarios, and key technology trends for 6G mobile communications

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Science China(Information Sciences) 2022年第5期65卷 5-31页

作者： Zhiqin WANG ying DU kejun WEI Kaifeng HAN Xiaoyan XU Guiming WEI Wen TONG Peiying ZHU Jianglei MA Jun WANG Guangjian WANG Xueqiang YAN Jiying XIANG He HUANG Ruyue LI Xinhui WANG yingmin WANG Shaohui SUN Shiqiang SUO Qiubin GAO Xin SU China Academy of Information and Communications Technology Huawei Technologies Canada Co. Ltd. Huawei Technologies Co. Ltd.(Hangzhou) Huawei Technologies Co. Ltd.(Chengdu) Huawei Technologies Co. Ltd.(Shanghai) ZTE Corporation Datang Mobile Communications Equipment Co. Ltd.

With the global commercialization of the fifth-generation(5G) network, many countries, including China, USA, European countries, Japan, and Korea, have started exploring 6G mobile communication network, following the tradition of “planning the next while commercializing one generation”. Currently,studies on 6G networks are at the infancy stage. Research on the vision and requirements for 6G is still ongoing, and the industry is yet to clarify the key enabling technologies for 6G. However, 6G will certainly build on the success of 5G. Therefore, developing high-quality 5G networks and seamlessly integrating 5G with verticals are the priorities before 2030, when 6G is projected to be commercialized. Also, global 5G standards will keep evolving to better support vertical applications. As a milestone, the Third-Generation Partnership Project(3GPP) published Release 16 in July 2020, which continuously enhanced the capabilities of mobile broadband service based on Release 15 and realized the support for low-delay and high-reliability applications, such as Internet of Vehicles and industrial Internet. Currently, 3GPP is working on Releases 17 and 18, focusing on meeting the demands of medium-and high-data-rate machine communication with low-cost and high-precision positioning, which will be published in June 2022. Thus, 6G networks will further expand the application fields and scope of the Internet of Things to accommodate those services and applications that are beyond the capabilities of 5G networks. Herein, we present our vision, application scenarios,and key technological trends for 6G networks. Furthermore, we propose several future research opportunities in 6G networks with regard to industrialization and standardization.

关键词： sixth-generation (6G) mobile communication holographic radio technology 6G vision application scenarios of 6G terahertz communication integrated sensing and communication integrated intelligence and communication ultra-massive MIMO reconfigurable intelligent surface co-frequency co-time full-duplex