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A novel stiffness optimization model of space telescopic boom based on locking mechanism

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Frontiers of Mechanical Engineering 2024年第3期19卷 41-59页

作者： Kun XU Xinghan ZHUANG zhou su Qiuhong LIN Shouzhi REN Hang XIAO Xilun DING School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China Beijing Institute of Spacecraft System Engineering Beijing 100094China

The deployable telescopic boom,whose mass and stiffness play crucial roles,is extensively used in the design of space-deployable ***,the most existing optimal design that neglects the influence of the locking mechanisms in boom joints cannot raise the whole stiffness while reducing the boom *** tackle this challenge,a novel optimization model,which utilizes the arrangement of the locking mechanisms to achieve synchronous improvement of the stiffness and mass,is *** proposed optimization model incorporates a novel joint stiffness model developed based on an equivalent parallel mechanism that enables the consideration of multiple internal stiffness factors of the locking mechanisms and tubes,resulting in more accurate representations of the joint stiffness *** analysis shows that the proposed stiffness model achieves more than at least 11% improved accuracy compared with existing ***,case verification shows that the proposed optimization model can improve stiffness while effectively reducing mass,and it is applied in boom optimization design.

关键词： deployable telescopic boom locking mechanism stiffness model clearance error optimization model

Erythrodermic mycosis fungoides: A case report

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World Journal of Clinical Cases 2024年第1期12卷 130-135页

作者： Wu-Bing Xu Ya-Ping Zhang su-Ping zhou Hao-Yang Bai Department of Radiology Shaoxing People’s HospitalKey Laboratory of Functional Molecular Imaging of Tumor and Interventional Diagnosis and Treatment of Shaoxing CityShaoxing 312000Zhejiang ProvinceChina

BACKGROUND Mycosis fungoides is the most common primary cutaneous T-cell lymphoma,whereas generalized erythroderma is *** this report,we describe a case of mycosis fungoides with generalized erythroderma using complete clinical data and[18F]fluoroDglucose positron emission tomography/computed tomography(18F-FDG PET/CT)*** suMMARY Systemic skin redness with desquamation for three years confirmed mycosis fungoides within one *** patient underwent left axillary lymphadenectomy biopsy;pathological biopsy suggested abnormal T-cell lesions consistent with mycosis fungoides involving lymph *** patient received methotrexate,5 mg twice weekly,as part of their chemotherapy *** January half after discharge,no obvious cause of high fever,left axillary lymph nodes with red heat pain,and rupture entered our hospital for *** The 18F-FDG PET/CT is essential for early diagnosis and timely treatment.

关键词： Mycosis fungoides Positron emission tomography/computed tomography Imaging Diagnosis Differential diagnosis Treatment Case report

High-pressure capacity expansion and water injection mechanism and indicator curve model for fractured-vuggy carbonate reservoirs

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PETROLEUM 2024年第3期10卷 511-519页

作者： Chen, Lixin Jia, Chengzao Zhang, Rujie Yue, Ping Jiang, Xujian Wang, Junfang su, zhou Xiao, Yun Lv, Yuan China Univ Petr Inst Unconvent Oil & Gas Sci & Technol Beijing 102249 Peoples R China Southwest Petr Univ State Key Lab Reservoir Geol & Dev Chengdu 610500 Peoples R China Tarim Oil field Co PetroChina Korla 841000 Peoples R China

Water injection for oil displacement is one of the most effective ways to develop fractured-vuggy carbonate reservoirs. With the increase in the number of rounds of water injection, the development effect gradually fails. The emergence of high-pressure capacity expansion and water injection technology allows increased production from old wells. Although high-pressure capacity expansion and water injection technology has been implemented in practice for nearly 10 years in fractured-vuggy reservoirs, its mechanism remains unclear, and the water injection curve is not apparent. In the past, evaluating its effect could only be done by measuring the injection-production volume. In this study, we analyze the mechanism of high-pressure capacity expansion and water injection. We propose a fluid exchange index for high-pressure capacity expansion and water injection and establish a discrete model suitable for high-pressure capacity expansion and water injection curves in fractured-vuggy reservoirs. We propose the following mechanisms: replenishing energy, increasing energy, replacing energy, and releasing energy. The above mechanisms can be identified by the high-pressure capacity expansion and water injection curve of the well HA6X in the Halahatang Oilfield in the Tarim Basin. By solving the basic model, the relative errors of Reservoirs I and II are found to be 1.9% and 1.5%, respectively, and the application of field examples demonstrates that our proposed high-pressure capacity expansion and water injection indicator curve is reasonable and reliable. This research can provide theoretical support for high-pressure capacity expansion and water injection technology in fracture-vuggy carbonate reservoirs.

关键词： Fractured-vuggy carbonate reservoirs High-pressure capacity expansion and water injection Mechanism Water injection indicator curve ENHANCED OIL-RECOVERY STRESS SENSITIVITY TARIM BASIN FIELD

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大功率质子交换膜燃料电池建模及仿真

太阳能学报 2024年第3期45卷 290-297页

作者：陈家城周苏福州职业技术学院交通工程系福州365108 同济大学汽车学院上海201804

针对70 kW大功率燃料电池系统进行建模,基于Simulink平台搭建质子交换膜燃料电池电堆系统模型。基于该模型在稳态下研究温度、膜含水量、压力对电池输出性能的影响,分析水气跨膜运输情况。仿真结果表明电流密度在0.4~1.0 A/cm范围内时,... 详细信息

针对70 kW大功率燃料电池系统进行建模,基于Simulink平台搭建质子交换膜燃料电池电堆系统模型。基于该模型在稳态下研究温度、膜含水量、压力对电池输出性能的影响,分析水气跨膜运输情况。仿真结果表明电流密度在0.4~1.0 A/cm范围内时,电堆输出电压保持稳定。然后在新欧洲驾驶循环(NEDC)动态工况下,分析电池系统输出性能和水气跨膜传输情况,结果表明所建模型可用于大功率车用PEMFC研究。

关键词：质子交换膜燃料电池 Simulink 仿真模型电压特性质量传输动态分析

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液舱运动与流体晃荡耦合运动数值模拟与试验验证

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船舶力学 2024年第10期28卷 1516-1525页

作者：刘文夫周素素杨旭陈磊中国船舶及海洋工程设计研究院

本文针对液舱运动与流体晃荡耦合运动问题，采用基于Hilber-Hughes-Taylor(HHT)格式的隐式直接积分法求解液舱运动，应用VOF法捕捉流体晃荡自由表面运动，建立液舱运动与流体晃荡双向耦合迭代算法。将算法应用到某转动液舱系统的模型试... 详细信息

本文针对液舱运动与流体晃荡耦合运动问题，采用基于Hilber-Hughes-Taylor(HHT)格式的隐式直接积分法求解液舱运动，应用VOF法捕捉流体晃荡自由表面运动，建立液舱运动与流体晃荡双向耦合迭代算法。将算法应用到某转动液舱系统的模型试验中，通过数值计算结果与试验结果的比较验证算法的有效性。本文建立的分析方法可为液舱运动与流体晃动耦合运动问题提供一种有效的分析方法。

关键词：液舱运动流体晃荡 HHT方法 VOF方法

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基于三元组网络和混合粒子群的碎纸拼接算法

华中科技大学学报（自然科学版） 2024年第7期52卷 22-28页

作者：陈志刚苏周方佳中南大学计算机学院湖南长沙410083 暨南大学信息科学技术学院广东广州510632

针对细粒度切割后的碎纸片聚类准确率低和启发式算法拼接效果一般的问题,提出了一种基于三元组网络和混合粒子群的碎纸片自动拼接算法.碎纸片拼接分为行间聚类、兼容性评估和行内拼接三个阶段.首先,在行间聚类阶段,对投影得到的图像向... 详细信息

针对细粒度切割后的碎纸片聚类准确率低和启发式算法拼接效果一般的问题,提出了一种基于三元组网络和混合粒子群的碎纸片自动拼接算法.碎纸片拼接分为行间聚类、兼容性评估和行内拼接三个阶段.首先,在行间聚类阶段,对投影得到的图像向量进行自适应填充以补充缺失的特征信息,再利用高斯混合模型聚类算法进行聚类;然后,在兼容性评估阶段,借助三元组网络模型,将聚类后的同一行图像映射到一个公共的度量空间,并得到一个区分度明显的距离矩阵;最后,将这个距离矩阵作为粒子的适应度值,提出了一种基于混合粒子群算法的行内拼接算法.实验结果表明:本文提出的拼接算法能够提升聚类准确率和拼接精度,在破碎文档重建工作上具有良好的效果.

关键词：碎纸片拼接混合粒子群算法高斯混合模型三元组损失卷积神经网络

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Design and prototyping of the readout electronics for the transition radiation detector in the high energy cosmic radiation detection facility

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Nuclear Science and Techniques 2024年第4期35卷 189-199页

作者： Jie-Yu Zhu Yang-zhou su Hai-Bo Yang Fen-Hua Lu Yan Yang Xi-Wen Liu Ping Wei Shu-Cai Wan Hao-Qing Xie Xian-Qin Li Cong Dai Hui-Jun Hu Hong-Bang Liu Shu-Wen Tang Cheng-Xin Zhao Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China Guangxi Key Laboratory for Relativistic Astrophysics School of Physical Science and TechnologyGuangxi UniversityNanning 530004China

The high energy cosmic-radiation detection(HERD)facility is planned to launch in 2027 and scheduled to be installed on the China Space *** serves as a dark matter particle detector,a cosmic ray instrument,and an observatory for high-energy gamma rays.A transition radiation detector placed on one of its lateral sides serves dual purpose,(ⅰ)calibrating HERD's electromagnetic calorimeter in the TeV energy range,and(ⅱ)serving as an independent detector for high-energy gamma *** this paper,the prototype readout electronics design of the transition radiation detector is demonstrated,which aims to accurately measure the charge of the anodes using the SAMPA application specific integrated circuit *** electronic performance of the prototype system is evaluated in terms of noise,linearity,and *** the presented design,each electronic channel can achieve a dynamic range of 0–100 fC,the RMS noise level not exceeding 0.15 fC,and the integral nonlinearity wassults show that the prototype system can satisfy the requirements of the detector's scientific goals.

关键词： HERD Dark matter particle detection TRD Readout electronics SAMPA Data acquisition Performance test

基于一维多尺度神经网络和库普曼池化的滚动轴承故障诊断方法

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科学技术与工程 2024年第24期24卷 10297-10304页

作者：孙祯周素霞北京建筑大学机电与车辆工程学院北京100044 北京建筑大学城市轨道交通车辆服役性能保障北京市重点实验室北京100044

滚动轴承作为机械运转的核心部件,其发生故障会导致旋转机械运行状态的恶化。卷积网络作为滚动轴承故障诊断的一种方法,针对其固定窗口局限性,结合一维卷积神经网络(1D convolutional neural network, 1D-CNN)在处理一维数据的优势,利... 详细信息

滚动轴承作为机械运转的核心部件,其发生故障会导致旋转机械运行状态的恶化。卷积网络作为滚动轴承故障诊断的一种方法,针对其固定窗口局限性,结合一维卷积神经网络(1D convolutional neural network, 1D-CNN)在处理一维数据的优势,利用多尺度思想在同一层同时使用不同大小的窗口提取信号特征,根据时间维度信息对异常检测方法的影响,将1D-CNN的池化层与Koopman模型结合,得到高阶动态特征;最后将所得到的故障特征输入全连接层中进行故障诊断。为验证模型优势,对所提出的初始模型和两种改进模型在相同工况下进行对比,同时与支持向量机(support vector machine, SVM)和BP神经网络(back propagation neural network, BPNN)等算法进行对比分析。结果表明:所提模型的识别效果较好,滚动轴承故障准确率可以达到99.99%。

关键词：滚动轴承故障诊断一维多尺度卷积网络(1D-CNN) Koopman池化

混合联肢部分外包组合剪力墙基于两阶段耗能的塑性设计方法研究

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工程力学 2024年第2期41卷 137-150页

作者：石韵刘万鹏苏明周周巧玲刘少博西安石油大学土木工程系陕西西安710065 西安建筑科技大学土木工程学院陕西西安710055 四川省建筑设计研究院有限公司四川成都610041

混合联肢部分外包组合剪力墙结构是一种典型的两阶段耗能结构体系。依据现行设计规范设计的混合联肢部分外包组合剪力墙结构对结构弹塑性阶段的整体性能缺乏考虑,在设防地震和罕遇地震作用下结构的屈服顺序难以控制。基于混合联肢部分... 详细信息

混合联肢部分外包组合剪力墙结构是一种典型的两阶段耗能结构体系。依据现行设计规范设计的混合联肢部分外包组合剪力墙结构对结构弹塑性阶段的整体性能缺乏考虑,在设防地震和罕遇地震作用下结构的屈服顺序难以控制。基于混合联肢部分外包组合剪力墙结构体系“小震不坏,中震可修,大震不倒”的三水准抗震设防性能目标,提出结构两阶段耗能的塑性设计方法。以目标位移和理想破坏模式作为预测结构弹塑性受力状态性能目标,针对不同地震水准下的性能目标,考虑耦连比对结构合理耗能机制的影响,将结构的能力曲线等效为三线型,改进了传统基于能量平衡的塑性设计方法,保证结构在设防地震及罕遇地震下实现理想屈服顺序,避免薄弱层产生。采用建议的设计方法设计了一个12层结构算例,并采用ABAQUS对算例进行推覆分析和弹塑性时程分析。结果表明,采用基于两阶段耗能的塑性设计方法预测的中震及大震下结构顶点位移角与数值分析结果误差分别为0.5%和12.1%,最大层间位移角满足结构弹塑性层间位移角的要求。算例结构能够实现“强节点弱构件、强墙肢弱连梁”合理的屈服顺序,保证结构预期的失效机制和不同地震水准作用下的性能目标,验证了基于两阶段耗能的塑性设计方法的有效性。

关键词：结构工程混合联肢墙塑性设计部分外包组合剪力墙两阶段耗能性能目标耦连比

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