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Friction 2024年第2期12卷 305-318页

作者： Yangyang ZHAO Guoyuan ZHANG junqian wang He wang Weigang ZHAO Qunfeng ZENG School of Mechano-Electronic Engineering Xidian UniversityXi’an 710071China Xi’an Aerospace Propulsion Institute Xi’an 710071China Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System Xi’an Jiaotong UniversityXi’an 710049China

The friction coefficient and wear rate of pretreated graphite with liquid nitrogen were obtained by using a ball-on-disk tester,and the wear of GCr15–graphite seal pairs with the low-temperature time-dependent pretreatment was discussed by comparing the wear *** results show that liquid nitrogen pretreatment can affect the hardness and interlayer spacing of *** range of the friction coefficients of pretreated graphite changes from 0.17 to *** the increase of liquid nitrogen pretreatment time,the wear mechanism of graphite would change from dominated three-body wear to adhesion *** experimental results of the mechanical seal with liquid nitrogen pretreatment show that the wear rate of stator is less than 0.00165 mm^(3)·N^(−1)·m^(−1),and the graphite shows a good low-temperature compatibility.

关键词： graphite low-temperature pretreatment mechanical seal friction and wear

亚低温干预通过改善线粒体功能抑制干扰素-α2b诱导的人心肌细胞AC16凋亡

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中国循环杂志 2024年第1期39卷 75-82页

作者：王俊乾周灵杉朱友琦乙成成白明兰州大学第一医院心脏中心甘肃省心血管病临床医学研究中心甘肃省心血管疾病重点实验室兰州730000 兰州大学第一医院老年病科兰州730000

目的:分析亚低温在Ⅰ型干扰素(干扰素-α2b)诱导的人心肌细胞AC16凋亡过程中的作用及分子机制。方法:不同浓度的干扰素-α2b在不同时间点刺激人心肌细胞AC16,CCK-8检测心肌细胞增殖;流式细胞仪检测干扰素-α2b刺激心肌细胞后常温、亚低... 详细信息

目的:分析亚低温在Ⅰ型干扰素(干扰素-α2b)诱导的人心肌细胞AC16凋亡过程中的作用及分子机制。方法:不同浓度的干扰素-α2b在不同时间点刺激人心肌细胞AC16,CCK-8检测心肌细胞增殖;流式细胞仪检测干扰素-α2b刺激心肌细胞后常温、亚低温对细胞的影响;线粒体Mito-Tracker绿色荧光探针染色激光共聚焦成像观察线粒体形态的变化;流式细胞仪检测不同干预条件下线粒体膜电位变化情况;通过线粒体Mito-Tracker绿色荧光探针染色激光共聚焦成像评估线粒体动力相关蛋白1(Drp1)与线粒体的共定位情况及不同干预条件对线粒体的影响;使用蛋白免疫印迹法检测不同干预条件下,磷酸化Drp1 Ser616、Drp1、核酶多聚二磷酸腺苷核糖聚合酶1(PARP1)、剪切型PARP1(cleaved-PARP1)蛋白表达变化。结果:CCK-8及流式细胞仪检测发现干扰素-α2b抑制AC16细胞增殖,并可诱导AC16细胞凋亡,亚低温干预发挥心肌保护作用;不同干预条件下,AC16细胞线粒体损伤程度不一,表现为亚低温干预细胞具有较好的线粒体形态和更高的线粒体膜电位;Mito-Tracker绿色荧光探针检测发现心肌细胞损伤时Drp1从胞浆转移至线粒体中参与线粒体分裂,且亚低温干预发挥抑制作用;蛋白免疫印迹法检测发现亚低温干预后磷酸化Drp1 Ser616/Drp1和cleaved-PARP1/PARP1显著降低,且线粒体分裂抑制剂1(Mdivi-1)预处理可部分逆转上述现象。结论:亚低温干预通过改善线粒体功能抑制Ⅰ型干扰素-α2b诱导的人心肌细胞AC16凋亡。

关键词：干扰素-α2b 亚低温心肌炎线粒体功能细胞凋亡

Two-view attention-guided convolutional neural network for mammographic image classification

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CAAI Transactions on Intelligence Technology 2023年第2期8卷 453-467页

作者： Lilei Sun Jie Wen junqian wang Yong Zhao Bob Zhang Jian Wu Yong Xu College of Computer Science and Technology Guizhou UniversityGuiyangChina Shenzhen Key Laboratory of Visual Object Detection and Recognition Harbin Institute of TechnologyShenzhenChina Harbin Institute of Technology ShenzhenChina School of Electronic and Computer Engineering Shenzhen Graduate School of Peking UniversityShenzhenChina Department of Computer and Information Science University of MacaoTaipaChina Science for Life Laboratory KTH Royal Institute of TechnologyStockholmSweden

Deep learning has been widely used in the field of mammographic image classification owing to its superiority in automatic feature ***,general deep learning models cannot achieve very satisfactory classification results on mammographic images because these models are not specifically designed for mammographic images and do not take the specific traits of these images into *** exploit the essential discriminant information of mammographic images,we propose a novel classification method based on a convolutional neural ***,the proposed method designs two branches to extract the discriminative features from mammographic images from the mediolateral oblique and craniocaudal(CC)mammographic *** features extracted from the two-view mammographic images contain complementary information that enables breast cancer to be more easily ***,the attention block is introduced to capture the channel-wise information by adjusting the weight of each feature map,which is beneficial to emphasising the important features of mammographic ***,we add a penalty term based on the fuzzy cluster algorithm to the cross-entropy function,which improves the generalisation ability of the classification model by maximising the interclass distance and minimising the intraclass distance of the *** experimental results on The Digital database for Screening Mammography INbreast and MIAS mammography databases illustrate that the proposed method achieves the best classification performance and is more robust than the compared state-ofthe-art classification methods.

关键词： convolutional neural network deep learning medical image processing mammographic image

Rapid Access to Chiralα-Alkylated Azacycles via NiH-Catalyzed Asymmetric Migratory Hydroalkylation of N-Heterocyclic Alkenes

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CCS Chemistry 2024年第4期6卷 898-904页

作者： Changpeng Chen Wenqing Guo Deyong Qiao junqian Zhou You wang Shaolin Zhu State Key Laboratory of Coordination Chemistry Jiangsu Key Laboratory of Advanced Organic MaterialsChemistry and Biomedicine Innovation Center(ChemBIC)School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210093 School of Chemistry and Chemical Engineering Henan Normal UniversityXinxiang 453007 Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs Shanghai Jiao Tong UniversityShanghai 200240

Asymmetric migratory hydrofunctionalization of isomeric mixtures of alkenes provides a complementary approach for the selective introduction of a functional group into a remote C(sp3)-H ***,the simultaneous control of both regio-and enantioselectivity in this migratory process is a ***α-alkyl-substituted azacycles are key motifs in pharmaceuticals,natural products,and ***,we report a NiH-catalyzed asymmetric migratory hydroalkylation process for their efficient and selective *** this process,easily available isomeric mixtures of N-heterocyclic alkenes can be directly employed as starting materials,convergently delivering a variety of enantioenrichedα-alkylated azacycles with high levels of regio-and *** synthetic utility of this transformation is demonstrated by the facile synthesis of two bioactive alkaloids,(+)-connine and(R)-*** obtained chiralα-alkylated azacycles also readily undergo diverse derivatization,such as deconstructive halogenation and ring contraction.

关键词： alkenes alkylation asymmetric catalysis isomerization nickel

Three-stage network for age estimation

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CAAI Transactions on Intelligence Technology 2019年第2期4卷 122-126页

作者： Yu Tingting wang junqian Wu Lintai Xu Yong School of Computer Science and Technology Harbin Institute of Technology (Shenzhen) Shenzhen People’s Republic of China

Age estimation on the basis of the face has been widely used in the field of human–computer interaction and intelligent surveillance. Many existing methods extract deeper global features from the facial image and achieve significant improvement on age estimation. However, local features and their relationship are important for age estimation. In this study, the authors propose a model to use local features for age estimation. The proposed model consists of three stages, preliminary abstraction stage for extracting deeper features, local feature encoding stage to model the relationship between local features and recall stage for the combination of temporary local impressions. Extensive experiments show that their proposed method outperforms previous state-of-the-art methods.

关键词： estimation methods show

Enhanced CNN for image denoising

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CAAI Transactions on Intelligence Technology 2019年第1期4卷 17-23页

作者： Chunwei Tian Yong Xu Lunke Fei junqian wang Jie Wen Nan Luo Bio-Computing Research Center Harbin Institute of TechnologyShenzhenShenzhen 518055People’s Republic of China Shenzhen Medical Biometrics Perception and Analysis Engineering Laboratory Harbin Institute of TechnologyShenzhenShenzhen 518055People’s Republic of China School of Computer Science and Technology Guangdong University of TechnologyGuangzhou 510006People’s Republic of China Institute of Automation Heilongjiang Academy of Sciences Harbin 150090People’s Republic of China

Owing to the flexible architectures of deep convolutional neural networks(CNNs)are successfully used for image ***,they suffer from the following drawbacks:(i)deep network architecture is very difficult to train.(ii)Deeper networks face the challenge of performance *** this study,the authors propose a novel method called enhanced convolutional neural denoising network(ECNDNet).Specifically,they use residual learning and batch normalisation techniques to address the problem of training difficulties and accelerate the convergence of the *** addition,dilated convolutions are used in the proposed network to enlarge the context information and reduce the computational *** experiments demonstrate that the ECNDNet outperforms the state-of-the-art methods for image denoising.

关键词： ECNDNet CNNs

基于三参数S变换的多级重心频率衰减梯度属性分析

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中国海洋大学学报（自然科学版） 2023年第6期53卷 142-150页

作者：汪俊乾张会星中国海洋大学海底科学与探测技术教育部重点实验室山东青岛266100 青岛海洋科学与技术试点国家实验室海洋矿产资源评价与探测技术功能实验室山东青岛266237

本文提出一种基于三参数S变换的多级重心频率衰减梯度属性并将其用于储层预测。首先,利用三参数S变换计算地震信号目的层的时频谱;然后利用信号的多级重心选定拟合频段并计算每个时刻振幅谱的高频段频率衰减梯度,得到属性值;最后利用频... 详细信息

本文提出一种基于三参数S变换的多级重心频率衰减梯度属性并将其用于储层预测。首先,利用三参数S变换计算地震信号目的层的时频谱;然后利用信号的多级重心选定拟合频段并计算每个时刻振幅谱的高频段频率衰减梯度,得到属性值;最后利用频率衰减梯度属性值的变化进行含油气储层预测。理论模型和实际数据应用结果表明,与常规频率衰减梯度属性对比,基于三参数S变换提取的多级重心频率衰减梯度属性更加稳定,能更好地刻画储层的边界和识别油气。

关键词：三参数S变换衰减多级重心频率衰减梯度储层预测

低温高速动静结合型机械密封两相流仿真与实验

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航空学报 2023年第23期44卷 201-213页

作者：张国渊黎旭康赵伟刚赵洋洋王俊倩西安电子科技大学机电工程学院西安710071 西安航天动力研究所西安710100

液体火箭发动机高速涡轮泵轴端动静结合型机械密封端面液膜受低温、高速、高压等极端工况影响极易产生气液两相流现象;诱发两相流的机制及相变对密封的影响规律尚不明确,亟需发展相关的仿真模型并开展实验验证工作。以某高速涡轮泵用动... 详细信息

液体火箭发动机高速涡轮泵轴端动静结合型机械密封端面液膜受低温、高速、高压等极端工况影响极易产生气液两相流现象;诱发两相流的机制及相变对密封的影响规律尚不明确,亟需发展相关的仿真模型并开展实验验证工作。以某高速涡轮泵用动静结合型螺旋槽机械密封为研究对象,基于Laminar层流及Mixture多相流模型,开展了低温、高速等极端工况下密封间隙内流体的空化相变特性研究;以泄漏量、开启力与内部气相体积占比等性能参数为表征指标,分析了该类密封在液氮介质环境工况参数对两相流动特性和相态转变的影响规律。结果表明随着密封间隙增加将导致两相流在有限约束范围内的体积增大,较弱的动压效应导致内部压力产生较小变化进而使得空化相变能力减小;气相体积占比随着液膜温度的增加而增大,随着密封介质压力的增加而减小。开展了低温实验研究,并验证了仿真模型的正确性,理论与实验结果将有助于深入理解低温高速动静结合型机械密封两相流机理,对可重复高速涡轮泵的运行可靠性和稳定性提升具有重要的实践价值。

关键词：动静结合型机械密封两相流空化相变密封性能低温实验

Theoretical and experimental investigations on single-atom catalysis:Pt1/FeOx for water-gas shift reaction Shan-Fei wang1,§,Yangyang Li2,3,§,Haiyan wang1,Jin-Xia Liang1(✉),Chun Zhu1

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Nano Research 2024年第9期17卷 8627-8637页

作者： Shan-Fei wang Yangyang Li Haiyan wang Jin-Xia Liang Chun Zhu Botao Qiao School of Chemistry and Chemical Engineering Guizhou UniversityGuiyang 550025China CAS Key Laboratory of Science and Technology on Applied Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China University of Chinese Academy of Sciences Beijing 100049China

Oxide-supported metal single-atom catalysts(SACs)have exhibited excellent catalytic performance for water-gas shift(WGS)***,we report the single-atom catalyst Pt1/FeOx exhibits excellent medium temperature catalytic performance for WGS reactions by the density functional theory(DFT)calculations and experimental *** calculations indicate that H_(2)O molecules are easily dissociated at oxygen vacancies,and the formed*OH and*O are adsorbed on Pt1 single atoms and the adjacent O atoms,*** studying four possible reaction mechanisms,it is found that the optimal WGS reaction pathway is proceeded along the carboxyl mechanism(pathway III),in which the formation of*COOH intermediates can promote the stability of Pt1/FeOx SAC and the easier occurrence of WGS *** energy barrier of the rate-determining step during the entire reaction cycle is only 1.16 eV,showing the high activity for the medium temperature WGS reaction on Pt1/FeOx SAC,which was verified by experimental ***,the calculated turnover frequencies(TOFs)of CO_(2)and H_(2)formation on Pt1/FeOx at 610 K(337℃)can reach up to 1.14×10^(-3)s^(-1)·site^(-1)through carboxyl *** this work,we further expand the application potential of Pt1/FeOx SAC in WGS reaction.

关键词： water-gas shift(WGS)reaction single-atom catalyst(SAC) density functional theory(DFT) thermocatalysis

Determination of the Average Neutron Energy Using Cross Section Ratio of the 58Ni(n,p)58g+mCo/58Ni(n,2n)57Ni Reactions

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中国核科技报告 1989年第S1期 25-26页

作者： Yuan junqian wang Yongchang Qiu Jiuzi wang Huamin Ren Zhongliang Yang Jingkang(Lanzhou Univ.)

TheCo/Ni activation ratio of the nickel foils and the correspondingaverage neutron energy have been measured. The source neutrons were produced by the T(d,n)~4He reaction at 150 kVneutron *** nickel foils were irradiated at 0°,40°,60°,96°,110°,130°to the incident deuteron *** activities from the residual nuclides ofthe rcactionsNi(n,p)Co andNi(n,2n)Ni were then measured for *** self absorption correction of the sample and the coincidence summing

关键词： n,2n m)Co n,p Determination of the Average Neutron Energy Using Cross Section Ratio of the Ni Reactions