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结合概率密度函数和主动轮廓模型的磁共振图像分割

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光学精密工程 2014年第12期22卷 3435-3443页

作者：刘建磊隋青美朱文兴山东大学控制科学与工程学院山东济南250061 山东交通学院轨道交通学院山东济南250357

为了提高大脑磁共振图像的分割精度,提出了一种新的图像分割算法。首先,分析了常用于大脑磁共振图像分割的高斯混合模型和主动轮廓模型的优缺点,联合高斯混合模型的概率密度函数和主动轮廓模型的能量函数构造了一个新的能量函数。然后,... 详细信息

为了提高大脑磁共振图像的分割精度,提出了一种新的图像分割算法。首先,分析了常用于大脑磁共振图像分割的高斯混合模型和主动轮廓模型的优缺点,联合高斯混合模型的概率密度函数和主动轮廓模型的能量函数构造了一个新的能量函数。然后,利用遗传算法和最大期望算法获取概率密度函数的参数值。最后,利用水平集方法和梯度下降流法,对获得的能量函数进行最小化,从而得到最终的分割结果。与传统方法相比,本文算法对脑组织中的白质和灰质的分割精度分别提高了6.73%和14.07%。该算法利用像素点的区域信息和概率值驱动主动轮廓曲线的演化,能有效区分具有相近灰度值的不同区域,从而提高了大脑磁共振图像的分割精度。

关键词：磁共振图像分割遗传算法概率密度函数主动轮廓模型

Path Planning of Shallow Submersible Unmanned Ship Based on MSFA Method

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Path Planning of Shallow Submersible Unmanned Ship Based on ...

第32.中国过程控制会议(CPCC2.2.)

作者： lei Zhao Pengfei Zhi Wanlu zhu Haiyang Qiu Hui Wang Weiran Wang School of Electronic and Information Engineering Jiangsu University of Science and Technology

In order to enable the shallow submersible unmanned ship to quickly and accurately collect water area information when working in unknown waters,carry out real-time path planning,shorten the planned path,and solve the limitations of traditional unmanned ship path *** paper proposes a shallow submersible unmanned ship path planning method based on multi-sensor information fusion and firefly optimization algorithm(MSFA).First of all,real-time information of the water area is acquired through the sensors mounted on the shallow-submersible unmanned ship,information fusion is carried out,and real-time modeling of the water area ***,the Firefly algorithm is optimized to increase the computing speed to meet the needs of real-time path ***,the real-time model of the water environment based on multi-sensor information fusion is combined with the Firefly optimization algorithm to form a shallow submersible unmanned ship path planning based on MSFA ***,the method proposed by me was verified by simulation analysis.

关键词： shallow submersible unmanned ship data fusion firefly optimization algorithm route plan

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器官移植内科学杂志 2008年第1期3卷 12-16页

作者： Wenyu Zhao Li Zeng Youhua zhu Li Ming Wang Meisheng Zhou Peng Han lei Zhang Organ Transplantation Institute of PLA Changzheng Hospital The 2nd Military Medical University Shanghai 200003 China

Objective To summarize one-center clinical experience in living related donor kidney transplantation. Methods Eight-three living related donor kidney transplantations were performed at our center. Potential living related donors underwent fully preoperatively medical evaluation, including psychical evaluation. Except for 4 cases being donated by spouse, the others were donated by blood relationship donors. Ten donors underwent laparoscopic nephrectomy, and the others underwent open nephrectomy. Except for one case being donated by twin, immunosuppressive protocols consisting of CsA/FK506, MMF/Aza and steroid were used. Results No delayed graft function recovery (DGF) occurred. Acute rejection (AR) occurred in 8 recipients. All cases were reversed successfully by high dose of intravenous methylprednisolone or polyclonal anti-T-cell antibodies. After follow-up for 1 month to 8 years, 81 recipients with 81 grafts survived yet and kept normal kidney function without impairment of life quality. Two recipients died: one due to serious pulmonary infection, and another due to cryptococcal meningoencephalitis. Conclusion Both psychological and physical assessment of the donor and recipient are critical for the success. Surgeons should choose their most familiar way to perform the nephrectomy. The period of pre-transplantation dialysis should be shortened and the operation should be performed early. During the early period postoperatively, the dosage of immunosuppressants should be as high as that in cadaveric kidney transplantation. But lower-dose of sustained immunosuppressants could be used thereafter.

关键词：活体亲属供者肾移植技术临床分析手术治疗

Triglyceride glucose index predicts in-hospital mortality in patients with ST-segment elevation myocardial infarction who underwent primary angiography

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Journal of Geriatric Cardiology 2023年第3期20卷 185-194页

作者： Rui FU Yan-Yan ZHAO Kong-Yong CUI Jin-Gang YANG Hai-Yan XU Dong YIN Wei-Hua SONG Hong-Jian WANG Cheng-Gang zhu lei FENG Zhi-Fang WANG Qing-Sheng WANG Ye LU Ke-Fei DOU Yue-Jin YANG the CAMI Registry Investigators Cardiometabolic Medicine Center Department of CardiologyFuwai HospitalNational Center for Cardiovascular DiseasesState Key Laboratory of Cardiovascular DiseaseNational Clinical Research Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina Medical Research&Biometrics Center Fuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina Coronary Heart Disease Center Department of CardiologyFuwai HospitalNational Center for Cardiovascular DiseasesState Key Laboratory of Cardiovascular DiseaseNational Clinical Research Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina Department of Cardiology Xinxiang Central Hospitalthe Fourth Clinical College of Xinxiang Medical UniversityHenan ProvinceChina Department of Cardiology Qinhuangdao First HospitalHebei ProvinceChina

OBJECTIVES To assess the correlation between triglyceride glucose(TyG)index and in-hospital mortality in patients with ST-segment elevation myocardial infarction(STEMI).METHODS A total of 2.90 patients with STEMI who underwent primary angiography within 12.h from symptom onset were selected from the prospective,nationwide,multicenter CAMI *** index was calculated with the formula:Ln[fasting triglycerides(mmol/L)×fasting glucose(mmol/L)/2..Patients were divided into three groups according to the tertiles of TyG *** primary endpoint was in-hospital *** Overall,46 patients died during hospitalization,in-hospital mortality was 1.5%,2.2.,2.6%for tertile 1,tertile 2.and tertile 3,***,TyG index was not significantly correlated with in-hospital mortality in single-variable logistic regression ***,after adjusting for age and sex,TyG index was significantly associated with higher mortality when regarded as a continuous variable(adjusted OR=1.75,95%CI:1.16-2.63)or categorical variable(tertile 3 *** 1:adjus-ted OR=2.50,95%CI:1.14-5.49).Furthermore,TyG index,either as a continuous variable(adjusted OR=2.54,95%CI:1.42.4.54)or categorical variable(tertile 3 *** 1:adjusted OR=3.57,95%CI:1.2.-10.2.),was an independent predictor of in-hospital mortality after adjusting for multiple confounders in multivariable logistic regression *** subgroup analysis,the pro-gnostic effect of high TyG index was more significant in patients with body mass index2.P interaction=0.006).CONCLUSIONS This study showed that TyG index was positively correlated with in-hospital mortality in STEMI patients who underwent primary angiography,especially in underweight patients.

关键词： patients mortality angiography

具有SGCMG系统的挠性卫星姿态机动控制及验证

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宇航学报 2018年第1期29卷 43-51页

作者：袁利雷拥军姚宁刘洁朱琦北京控制工程研究所北京100094 空间智能控制技术重点实验室北京100094

针对挠性卫星在轨姿态快速机动的需求,开展了星体姿态机动控制方法及控制实现研究。基于建立的挠性卫星姿态跟踪控制误差方程,给出了PD控制与补偿控制相结合的姿态跟踪控制器形式;考虑系统实现的时延影响,利用经典频率分析方法选择了兼... 详细信息

针对挠性卫星在轨姿态快速机动的需求,开展了星体姿态机动控制方法及控制实现研究。基于建立的挠性卫星姿态跟踪控制误差方程,给出了PD控制与补偿控制相结合的姿态跟踪控制器形式;考虑系统实现的时延影响,利用经典频率分析方法选择了兼顾系统稳定性及宽带控制的控制参数;在控制具体实现中,采用一种新型的基于力矩矢量调节奇异规避操纵策略,克服常规鲁棒奇异规避操纵存在的框架"锁死"现象,在解决奇异规避的同时避免激发挠性振动。所提出方法的有效性通过了在轨验证。

关键词：挠性卫星姿态机动控制力矩陀螺(CMG) 奇异规避在轨验证

Evolution of V-containing phases during preparation of Al-based Al−V master alloys

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Transactions of Nonferrous Metals Society of China 2022年第7期32卷 2110-2124页

作者： Yi MENG Yue YANG Cen LI lei-gang CAO Zhi-hao ZHAO Qing-feng zhu Jian-zhong CUI School of Mechanical and Materials Engineering North China University of TechnologyBeijing 100144China College of Materials Science and Engineering Northeastern UniversityShenyang 110004China Key Lab of Electromagnetic Processing of Materials Ministry of EducationNortheastern UniversityShenyang 110004China

Al-based Al−V master alloys were prepared by both the stepwise heating melting experiment and stepwise melting cooling experiment with rapid solidification to investigate the transformation of V-containing phases which gave different effects on microstructures and properties of commercial Al alloys and Ti alloys,as both melting and solidification processes affect the evolution of V-containing phases *** results showed that the raw Al−50wt.%V alloy consisted of needle-like Al_(3)V phase and Al8V5 phase(matrix),while petal-like Al_(3)V,needle-like Al_(7)V and plate-like Al_(10)V phase were present in the Al−V master *** metastable Al_(7)V phase was evolved from Al_(3)V phase and then evolved into Al_(10)V phase during melting *** number of Al_(10)V phase increased with the decrease of temperature in the range of 800−1000℃.Petal-like Al_(3)V phases could be transformed from Al_(8)V_(5) phase,pre-precipitated from Al−V molten liquid during melting process and precipitated directly during rapid solidification,respectively.

关键词： Al-based Al−V master alloy phase transformation vanadium-containing phase rapid solidification pouring temperature

长江中游城市群A级旅游景区空间演化及影响机理

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经济地理 2019年第1期39卷 198-206页

作者：贾垚焱胡静刘大均朱磊华中师范大学城市与环境科学学院中国湖北武汉430079 中国旅游研究院武汉分院中国湖北武汉430079 成都大学旅游与文化产业学院中国四川成都610106 安庆师范大学资源与环境学院中国安徽安庆246133

采用最邻近指数、核密度分析、网格维分析、地理探测器等分析方法,从空间分布类型、分布密度、分布均衡性等方面对长江中游城市群A级旅游景区的空间演化特征及影响机理进行研究,结果显示:(1)长江中游城市群A级旅游景区分布呈集聚型,其... 详细信息

采用最邻近指数、核密度分析、网格维分析、地理探测器等分析方法,从空间分布类型、分布密度、分布均衡性等方面对长江中游城市群A级旅游景区的空间演化特征及影响机理进行研究,结果显示:(1)长江中游城市群A级旅游景区分布呈集聚型,其集聚程度有逐渐增强的演变特征;(2.长江中游城市群A级旅游景区分布的高密度区呈现散点状结构向组团结构演变的特征,并逐步形成"U"字形核密度结构;(3)长江中游城市群A级旅游景区在空间上呈不等概率分布,存在围绕武汉、宜昌、长沙、南昌等城市集聚分布的现象,但呈现出不断均衡的发展趋势;(4)资源本底、市场条件及政策环境对长江中游城市群A级旅游景区空间分布的影响逐渐加强,不同等级旅游景区受到各影响因素的影响程度不同。

关键词：旅游业 A级旅游景区红色旅游景区资源本底跨区域旅游合作高铁旅游走廊长江中游城市群

三维多孔Sn-Zn合金电极助力Zn的均匀沉积/剥离

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高等学校化学学报 2022年第4期43卷 57-65页

作者：樊小勇朱永强毋妍张帅许磊苟蕾李东林长安大学材料科学与工程学院西安710061

通过在化学镀构建的三维多孔铜上电沉积锡-锌(Sn-Zn)合金,构筑了孔径为5μm左右的三维多孔Sn-Zn合金电极(3D Sn-Zn),对其形貌、结构和性能进行了表征和测定.结果表明,该电极拥有高稳定性和适宜孔径的三维多孔结构,可降低局部电流密度,... 详细信息

通过在化学镀构建的三维多孔铜上电沉积锡-锌(Sn-Zn)合金,构筑了孔径为5μm左右的三维多孔Sn-Zn合金电极(3D Sn-Zn),对其形貌、结构和性能进行了表征和测定.结果表明,该电极拥有高稳定性和适宜孔径的三维多孔结构,可降低局部电流密度,提供均匀的电场分布,缓解了由于锌的不均匀生长而造成的粗大枝晶;合金镀层中的Sn元素不仅可以增大析氢过电位,增强电极的防腐蚀性能,还可降低锌的形核势垒,为锌的沉积提供丰富的形核位点,促进锌在电极表面的均匀沉积,减少枝晶的形成.采用3D Sn-Zn电极组装的对称电池,在0.5 mA/cm^(2.下可稳定循环超过12.0 h,电压滞后仅为2..3 mV;而采用锌片(2. Zn)组装的对称电池电压滞后达到了99.2.mV,且在循环300 h后开始出现剧烈的电压波动.使用3D Sn-Zn电极组装的全电池在1.8 A/g电流密度下可稳定循环2.00次.

关键词：锌离子电池负极电化学沉积锡-锌合金三维多孔

叶片-双盘悬臂转子-同心型挤压油膜阻尼器系统的分岔与混沌

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哈尔滨工程大学学报 2011年第7期32卷 958-964页

作者：王立刚陈涛朱磊曹登庆哈尔滨工程大学理学院黑龙江哈尔滨150001 哈尔滨工业大学航天学院黑龙江哈尔滨150001

针对同心型挤压油膜阻尼器支承下的双盘悬臂转子系统,采用集中质量法和Lagrange方程,建立了叶片-双盘悬臂转子-CSFD系统的非线性动力学模型,并在模型中考虑了叶片的时变效应和惯性效应.采用正交变换将与转子横向振动耦合的叶片1-节径运... 详细信息

针对同心型挤压油膜阻尼器支承下的双盘悬臂转子系统,采用集中质量法和Lagrange方程,建立了叶片-双盘悬臂转子-CSFD系统的非线性动力学模型,并在模型中考虑了叶片的时变效应和惯性效应.采用正交变换将与转子横向振动耦合的叶片1-节径运动方程与叶片其他节径运动方程解耦,使得非线性耦合系统的自由度数由16+4n(n≥3)降低至2.,再采用周期变换,将耦合系统中的时变系数转化为常系数.通过数值求解并利用分岔图、轴心轨迹、Poincare映射图和频谱图等分析了系统响应的非线性特性.结果表明,系统响应中蕴含着倍周期、分岔和混沌等丰富的非线性动力学行为.研究显示,增大定心弹簧刚度有利于提高系统稳定性.

关键词：叶片悬臂转子系统挤压油膜阻尼器分岔混沌