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Formal[2+1]Cycloadditions of a Metallacyclopentadiene Unit with Alkynes:Constructing Tetracyclic Conjugated Frameworks with Bridgehead Metals

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Chinese Journal of Chemistry 2023年第16期41卷 1987-1993页

作者： zhenwei chu Jinhua Li Dafa Chen Zhengyu Lu Weiran Meng Ming Luo Haiping Xia Shenzhen Grubbs Institute and Guangdong Provincial Key Laboratory of Catalysis Department of ChemistrySouthern University of Science and TechnologyShenzhenGuangdong 518055China

Comprehensive Summary Metallacyclopentadienes play a vital role in transition-metal mediated and catalyzed cycloaddition reactions of alkynes.Though versatile reactions of metallacyclopentadienes with alkynes have been disclosed,[2+1]cycloadditions of metallacyclopentadienes and alkynes have never been discovered.In present work,we report the formal[2+1]cycloadditions of a metallacyclopentadiene unit with a broad scope of commercial alkynes,providing a facile strategy to construct tetracyclic conjugated compounds.The deuterated experiment indicates a metal vinylidene intermediate has been involved in[2+1]cycloaddition.Moreover,the electrophilic substitution reaction of the tetracyclic conjugated compound with the aid of density functional theory(DFT)calculated Fukui functions is investigated.

关键词： Metallacycle Cycloaddition Alkynes Electrophilic substitution Conjugation

The influence of alternating cyclic dynamic loads with different low frequencies on the bio-corrosion behaviors of AZ31B magnesium alloy in vitro

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Bioactive Materials 2022年第1期7卷 263-274页

作者： Linyuan Han zhenwei Zhang Jianwei Dai Xuan Li Jing Bai Zhihai Huang Chao Guo Feng Xue Chenglin chu School of Materials Science and Engineering Southeast UniversityNanjing211189JiangsuChina Jiangsu Key Laboratory for Advanced Metallic Materials Southeast UniversityNanjing211189JiangsuChina School of Materials Engineering Nanjing Institute of TechnologyNanjing211189JiangsuChina Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology Nanjing211189China

The real physiological environment of human body is complicated with different degrees and forms of dynamic loads applied to implanted medical devices due to the daily activities of the patients,which would have impacts on the degradation behaviors of magnesium alloy implants.In this work,the bio-corrosion behaviors of AZ31B magnesium alloy under alternating cyclic dynamic loads with different low frequencies(0.1-2.5 Hz)were specially investigated.It was found that the bio-degradation performances under external dynamic stressed conditions were much severer than those under unstressed conditions and static loads.The corrosion rates were generally accelerated as the rise of cyclic frequency.Hereby a numerical model for the degradation process of Mg alloy was established.The corrosion current density icorr of Mg alloy and the applied loading frequency f matches a linear relationship of ln icorr∝f,which is the result of interactions between the cyclic alternating load and corrosive environment.This work could provide a theoretical reference and an experimental basis for further researches on the biodegradation behaviors of biomedical materials under dynamic conditions.

关键词： Magnesium alloy Biocorrosion Fatigue Frequency

In vitro bio-corrosion behaviors of biodegradable AZ31B magnesium alloy under static stresses of different forms and magnitudes

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Journal of Magnesium and Alloys 2023年第3期11卷 1043-1056页

作者： Linyuan Han zhenwei Zhang Jianwei Dai Xuan Li Jing Bai Zhihai Huang Chao Guo Feng Xue Chenglin chu School of Materials Science and Engineering Southeast UniversityNanjing 211189China Jiangsu Key Laboratory for Advanced Metallic Materials Southeast UniversityNanjing 211189China School of Materials Engineering Nanjing Institute of TechnologyNanjing 211189China Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology Nanjing 211189China

Biomedical degradable materials would be subjected to different degrees and forms of static stress after being implanted in the human body.In this work,the biocorrosion behaviors of AZ31B magnesium alloy under different stress forms with different magnitudes(20~150MPa)were studied.It was found that the corrosion behaviors at stressed conditions were severer than those at unstressed conditions and corrosion rates were obviously accelerated.The biocorrosion behaviors are more sensitive to the effects of tensile loads than to compressive loads.A biocorrosion numerical model on the degradation process of Mg alloy under static loads was established.The corrosion current density(i_(corr))of Mg alloy and the applied static stress(σ)matches a linear relationship of ln i_(corr)~σwell during the early stage(within 24 hrs)while deviated gradually in the latter period of corrosion.This work could provide a guidance and theoretical reference for further researches on the biocorrosion behaviors and practical clinical applications of the biomedical materials subjected to physiological loads.

关键词： Magnesium alloy Biodegradable alloy Biocorrosion behavior Tensile loading Compressive loading

Safety of endovascular therapy for symptomatic intracranial artery stenosis:a national prospective registry

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Stroke & Vascular Neurology 2022年第2期7卷 166-171页

作者： Yabing Wang Tao Wang Adam Andrew Dmytriw Kun Yang Liqun Jiao Huaizhang Shi Jie Lu Tianxiao Li Yujie Huang zhenwei Zhao Wei Wu Jieqing Wan Qinjian Sun Bo Hong Yongli Li Liyong Zhang Jianfeng chu Qiong Cheng Yiling Cai Pengfei Wang Qi Luo Hua Yang Baijing Dong Yang Zhang Jun Zhao Zuoquan Chen Wei Li Xiaoxin Bai Weiwen He Xueli Cai Maimai Ti Osama O Zaidat Department of Neurosurgery Xuanwu HospitalBeijingChina Neuroendovascular Program Massachusetts General HospitalBostonMassachusettsUSA Department of Evidence-Based Medicine Xuanwu HospitalBeijingChina Department of Neurosurgery First Affiliated Hospital of Harbin Medical UniversityHarbinHeilongjiangChina Department of Radiology Xuanwu HospitalBeijingChina Center of Neurointerventional Therapy Henan Provincial People's HospitalZhengzhouChina Department of Neurology Nanjing Drum Tower HospitalNanjingJiangsuChina Department of Neurosurgery Tangdu Hospital Fourth Military Medical UniversityXi'anShaanxiChina Department of Neurology Shandong University Qilu HospitalJinanShandongChina Department of Neurosurgery Shanghai Jiao Tong University School of Medicine Affiliated Renji HospitalShanghaiShanghaiChina Department of Neurology Shandong Provincial HospitalJinanShandongChina Neusurgery Changhai HospitalShanghaiChina Department of Neurosurgery Second Affiliated Hospital of Harbin Medical UniversityHarbinHeilongjiangChina Department of Neurosurgery Liaocheng People's HospitalLiaocheng CityShandongChina Department of Neurosurgery Jining First People's HospitalJiningShandongChina Department of Neurology Fujian Provincial HospitalFuzhouFujianChina Department of Neurology 306 Hospital of People's Liberation ArmyBeijingChina Department of Neurosurgery Tianjin Huanhu HospitalTianjinTianjinChina Department of Neurosurgery Jilin University First HospitalChangchunJilinChina Department of Neurology Affiliated Hospital of Guiyang Medical CollegeGuiyangGuizhouChina Department of Neurosurgery Fourth Affiliated Hospital of Harbin Medical UniversityHarbinHeilongjiangChina Department of Neurosurgery Peking University First HospitalBeijingBeijingChina Department of Neurology Liaocheng Second People's HospitalLiaochengChina Department of Neurology Shanghai Tenth People's HospitalShanghaiChina Department of Neurosurgery Tianjin Medical University General HospitalTianjinTianjin

Introduction The safety outcomes of endovascular therapy for intracranial artery stenosis in a real-world stetting are largely unknown.The Clinical Registration Trial of Intracranial Stenting for Patients with Symptomatic Intracranial Artery Stenosis(CRTICAS)was a prospective,multicentre,real-world registry designed to assess these outcomes and the impact of centre experience.Methods 1140 severe,symptomatic intracranial arterial stenosis(ICAS)patients treated with endovascular therapy were included from 26 centres,further divided into three groups according to the annual centre volume of intracranial angioplasty and stent placement procedures over 2 years:(1)high volume for≥25 cases/year;(2)moderate volume for 10–25 cases/year and(3)low volume for<10 cases/year.Results The rate of 30-day stroke,transient ischaemic attack or death was 9.7%(111),with 5.4%,21.1%and 9.7%in high-volume,moderate-volume and low-volume centres,respectively(p<0.05).Multivariable logistic regression confirmed high-volume centres had a significantly lower primary endpoint compared with moderate-volume centres(OR=0.187,95%CI:0.056 to 0.627;p≤0.0001),while moderate-volume and low-volume centres showed no significant difference(p=0.8456).Conclusion Compared with the preceding randomised controlled trials,this real-world,prospective,multicentre registry shows a lower complication rate of endovascular treatment for symptomatic ICAS.Non-uniform utilisation in endovascular technology,institutional experience and patient selection in different volumes of centres may have an impact on overall safety of this treatment.

关键词： intracranial prospective stenosis

Combining quantitative and qualitative magnetic resonance imaging features to differentiate anorectal malignant melanoma from low rectal cancer

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Precision Clinical Medicine 2021年第2期4卷 119-128页

作者： Zeyan Xu Ke Zhao Lujun Han Pinxiong Li zhenwei Shi Xiaomei Huang chu Han Huihui Wang Minglei Chen Chen Liu Yanting Liang Suyun Li Yanqi Huang Xin Chen Changhong Liang Wuteng Cao Zaiyi Liu School of Medicine South China University of TechnologyGuangzhou 510006China Department of Radiology Guangdong Provincial People’s HospitalGuangdong Academy of Medical SciencesGuangzhou 510080China State Key Laboratory of Oncology in South China Collaborative Innovation Center of Cancer MedicineGuangzhou 510060China Department of Radiology Sun Yat-Sen University Cancer CenterGuangzhou 510060China Department of Radiology the Affiliated Hospital of Southwest Medical UniversityLuzhou 646000China The Second School of Clinical Medicine Southern Medical UniversityGuangzhou 510080China Shantou University Medical College Shantou 515041China Guangdong Cardiovascular Institute Guangdong Provincial People’s HospitalGuangdong Academy of Medical SciencesGuangzhou 510080China Department of Radiology Guangzhou First People’s Hospitalthe Second Affiliated Hospital of South China University of TechnologyGuangzhou 510180China Department of Radiology the Sixth Affiliated Hospital of Sun Yat-Sen UniversityGuangzhou 510655China

Background:Distinguishing anorectal malignant melanoma from low rectal cancer remains challenging because of the overlap of clinical symptoms and imaging findings.We aim to investigate whether combining quantitative and qualitative magnetic resonance imaging(MRI)features could differentiate anorectal malignant melanoma from low rectal cancer.Methods:Thirty-seven anorectal malignant melanoma and 98 low rectal cancer patients who underwent preoperative rectal MRI from three hospitals were retrospectively enrolled.All patients were divided into the primary cohort(N=84)and validation cohort(N=51).Quantitative image analysiswas performed on T1-weighted(T1WI),T2-weighted(T2WI),and contrast-enhanced T1-weighted imaging(CE-T1WI).The subjective qualitative MRI findings were evaluated by two radiologists in consensus.Multivariable analysis was performed using stepwise logistic regression.The discrimination performance was assessed by the area under the receiver operating characteristic curve(AUC)with a 95%confidence interval(CI).Results:The skewness derived from T2WI(T2WI-skewness)showed the best discrimination performance among the entire quantitative image features for differentiating anorectal malignant melanoma from low rectal cancer(primary cohort:AUC=0.852,95%CI 0.788–0.916;validation cohort:0.730,0.645–0.815).Multivariable analysis indicated that T2WI-skewness and the signal intensity of T1WI were independent factors,and incorporating both factors achieved good discrimination performance in two cohorts(primary cohort:AUC=0.913,95%CI 0.868–0.958;validation cohort:0.902,0.844–0.960).Conclusions:Incorporating T2WI-skewness and the signal intensity of T1WI achieved good performance for differentiating anorectal malignant melanoma from low rectal cancer.The quantitative image analysis helps improve diagnostic accuracy.

关键词： anorectal malignant melanoma low rectal cancer magnetic resonance imaging quantitative image analysis

基于模糊多属性决策方法的枢纽机场服务质量评价研究

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综合运输 2022年第9期44卷 45-52页

作者：褚衍昌黄世伟宋振伟中国民航大学经济与管理学院天津300300 中国民航大学交通科学与工程学院天津300300

本文从旅客登机流程入手分析枢纽机场服务质量影响因素,构建枢纽机场服务质量评价指标体系。引入语言分量的概念,建立基于模糊Topsis、模糊灰色关联度和模糊VIKOR方法的组合评价模型,对首都机场、虹桥机场、浦东机场、白云机场、双流机... 详细信息

本文从旅客登机流程入手分析枢纽机场服务质量影响因素,构建枢纽机场服务质量评价指标体系。引入语言分量的概念,建立基于模糊Topsis、模糊灰色关联度和模糊VIKOR方法的组合评价模型,对首都机场、虹桥机场、浦东机场、白云机场、双流机场五个枢纽机场的服务质量进行实证分析。结合评价指标体系中各指标的重要程度和评价结果,从中枢航线网络建设、周边交通管理等方面提出提升枢纽机场服务质量的建议。

关键词：枢纽机场服务质量评价三角模糊数语言分量多属性决策

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振动圆盘类转子构件在流体中受到的作用力

振动工程学报 2004年第Z1期17卷 6-8页

作者：袁振伟褚福磊王三保清华大学精密仪器与机械学系北京100084 郑州大学化工学院郑州450002 清华大学精密仪器与机械学系北京100084 郑州大学化工学院郑州450002

依据流体力学的粘性阻力理论,以运动的转子构件为主体,利用矢量分析方法,导出了薄圆盘单独在流体中分别作平移和转角振动时受到的流体阻力解析表达式,并得到几点结论.这些公式可用于转子系统的流固耦合动力学有限元建模,同时对流体机械... 详细信息

依据流体力学的粘性阻力理论,以运动的转子构件为主体,利用矢量分析方法,导出了薄圆盘单独在流体中分别作平移和转角振动时受到的流体阻力解析表达式,并得到几点结论.这些公式可用于转子系统的流固耦合动力学有限元建模,同时对流体机械及潜液机械构件的动力学设计具有一定指导意义.

关键词：圆盘转子构件振动流体阻力

FAST工程主动反射面健康监测系统温度信号多元回归估测

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天文研究与技术 2022年第5期19卷 493-499页

作者：孙晓王清梅李振伟乔峰楚敬敬青岛科技大学自动化与电子工程学院山东青岛266061 中国科学院国家天文台北京100101

大型结构健康监测系统中,温度测点故障会带来安全隐患。基于500 m口径球面射电望远镜(Five-hundred-meter Aperture Spherical radio Telescope,FAST)主动反射面健康监测系统,提取并分析了9个测点数据间的线性相关性,将候选变量分组并... 详细信息

大型结构健康监测系统中,温度测点故障会带来安全隐患。基于500 m口径球面射电望远镜(Five-hundred-meter Aperture Spherical radio Telescope,FAST)主动反射面健康监测系统,提取并分析了9个测点数据间的线性相关性,将候选变量分组并选择最优回归子集,建立多元线性回归模型,融合正常测点数据对故障测点进行估测。针对变量间多重共线性问题进一步应用岭回归法,选定岭参数为6。使用F检验与拟合度检验模型的显著性和有效性,使用不同时日数据验证模型的估测精度。结果证明,多元线性回归模型比单变量具有更高的拟合度和精度,均方根误差为0.475℃;岭回归法稳定性更高,均方根误差为0.435℃。

关键词： 500 m口径球面射电望远镜温度传感器结构健康监测多元线性回归岭回归

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指数复合型低频压电雾化喷头的设计

压电与声光 2019年第2期41卷 225-228页

作者：靳振伟储成智谷森徐伟汝长海苏州大学机器人与微系统研究中心江苏苏州215021 苏州纳米科技协同创新中心江苏苏州215021

设计一种频率为40 kHz的指数复合型低频压电雾化喷头,建立有限元模型,通过喷头模型的模态分析和谐响应分析来测定喷头模型的振动形态、谐振频率和雾化振幅。模态在八阶时喷头为纯拉伸状态,谐振频率为39 550 Hz,在设定电压为26 V时,仿真... 详细信息

设计一种频率为40 kHz的指数复合型低频压电雾化喷头,建立有限元模型,通过喷头模型的模态分析和谐响应分析来测定喷头模型的振动形态、谐振频率和雾化振幅。模态在八阶时喷头为纯拉伸状态,谐振频率为39 550 Hz,在设定电压为26 V时,仿真得到雾化振幅为3.9μm。采用德国Polytec高性能单点式激光测振仪测得喷头样机的振动幅值为3.94～4.32μm,误差小于10%,符合设计的要求。采用马尔文Spraytec型激光粒度仪对样机雾滴均匀性进行测量,当驱动电压为26 V时,喷头雾化产生的雾滴直径为SymbolFC@(30～95)μm,占比超过85%,结果表明,该喷头雾化液滴分布较均匀。

关键词：压电喷头指数型有限元分析均匀性