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NONLINEAR DYNAMICS RESPONSE OF CASING PIPE UNDER COMBINED WAVE-CURRENT

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Applied Mathematics and Mechanics(English Edition) 2005年第8期26卷 1040-1046页

作者： TANG You-gang（唐友刚） gu jia-yang（谷家扬） ZUO jian-li（左建立） MIN jian-qin（闵建琴） Department of Naval Architecture and Ocean Engineering School of Civil Engineering Tianjin University Tianiin 300072. P. R. China

The vortex-induced nonlinear vibration of casing pipes in the deep water was studied considering the loads of current and combined wave-current. The vortex-induced vibration equation of a casing pipe was set up considering the beam mode and Morison＇s nonlinear fluid loads as well as the vortex-excited loads. The approach of calculating vortex-excited nonlinear vibration by Galerkin＇s method was proposed. The natural vibration frequencies and modes were obtained, and the response including primary resonance induced by current and the composite resonance under combined wave-current for the 170 m long casing pipe in the 160 m depth of water were investigated. The results show that the dynamics response of casing pipe obviously increases, and the complicated response behaviors of casing pipe are described under combined wavecurrent.

关键词： casing pipes in the deep water fluid dynamics combined wave-current vortex-excited vibration composite resonance

Alterations of gut microbiota diversity, composition and metabonomics in testosterone-induced benign prostatic hyperplasia rats

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Military Medical Research 2023年第1期10卷 1-16页

作者： Lu-Yao Li Jie Han Lan Wu Cheng Fang Wei-guang Li jia-Min gu Tong Deng Chang-jiang Qin jia-Yan Nie Xian-Tao Zeng Center for Evidence‑Based and Translational Medicine Zhongnan Hospital of Wuhan UniversityWuhan 430071China Department of Gastrointestinal Surgery Huaihe Hospital of Henan UniversityKaifeng 475000HenanChina Department of Gastroenterology Zhongnan Hospital of Wuhan UniversityWuhan 430071China Department of Stomatology Zhongnan Hospital of Wuhan UniversityWuhan 430071China Department of Urology Zhong‑nan Hospital of Wuhan UniversityWuhan 430071China

Background: Studies had shown many diseases affect the stability of human microbiota, but how this relates to benign prostatic hyperplasia(BPH) has not been well understood. Hence, this study aimed to investigate the regulation of BPH on gut microbiota composition and ***: We analyzed gut samples from rats with BPH and healthy control rats, the gut microbiota composition and metabonomics were detected by 16S rDNA sequencing and liquid chromatography tandem mass spectrometry(LC–MS/MS).Results: High-throughput sequencing results showed that gut microbiota beta-diversity increased(P0.05), Bacteroidetes(46.54% vs. 41.64%,P>0.05), Clostridia(50.89% vs. 54.66%, P>0.05), Ruminococcaceae(25.67% vs. 20.56%, P>0.05). LC–MS/MS of intestinal contents revealed that differential metabolites were mainly involved in cellular processes, environmental information processing, metabolism and organismal systems. The most important pathways were global and overview maps, lipid metabolism, amino acid metabolism, digestive system and endocrine system. Through enrichment analysis, we found that the differential metabolites were significantly enriched in metabolic pathways, steroid hormone biosynthesis,ovarian steroidogenesis, biosynthesis of unsaturated fatty acids and bile secretion. Pearson correlation analysis(R=0.94) showed that there was a strong correlation between Prevotellaceae, Corynebacteriaceae, Turicibacteraceae,Bifid

关键词： Benign prostatic hyperplasia gut microbiota Intestinal metabolites Microbial diversity

Keypoints and Descriptors Based on Cross-Modality Information Fusion for Camera Localization

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Wuhan University Journal of Natural Sciences 2021年第2期26卷 128-136页

作者： MA Shuo GAO Yongbin+ TIAN Fangzheng LU Junxin HUANG Bo gu jia ZHOU Yilong College of Electronic and Electrical Engineering Shanghai University of Engineering ScienceShanghai 201620China

To address the problem that traditional keypoint detection methods are susceptible to complex backgrounds and local similarity of images resulting in inaccurate descriptor matching and bias in visual localization, keypoints and descriptors based on cross-modality fusion are proposed and applied to the study of camera motion estimation. A convolutional neural network is used to detect the positions of keypoints and generate the corresponding descriptors, and the pyramid convolution is used to extract multi-scale features in the network. The problem of local similarity of images is solved by capturing local and global feature information and fusing the geometric position information of keypoints to generate descriptors. According to our experiments, the repeatability of our method is improved by 3.7%, and the homography estimation is improved by 1.6%. To demonstrate the practicability of the method, the visual odometry part of simultaneous localization and mapping is constructed and our method is 35% higher positioning accuracy than the traditional method.

关键词： keypoints descriptors cross-modality information global feature visual odometry

白噪声海浪激励下船舶非线性横摇运动的概率分析(英文)

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船舶力学 2006年第3期10卷 17-25页

作者：谷家扬江苏科技大学船舶与海洋工程学院江苏镇江212003

应用求解FPK方程近似解的一种新理论研究白噪声激励下船舶非线性横摇运动的联合概率密度函数及稳定期望穿阈率。船舶随机横摇运动微分方程考虑到阻尼力与恢复力的非线性。新理论基于减少FPK方程的误差以获得参数化的联合概率密度函数。... 详细信息

应用求解FPK方程近似解的一种新理论研究白噪声激励下船舶非线性横摇运动的联合概率密度函数及稳定期望穿阈率。船舶随机横摇运动微分方程考虑到阻尼力与恢复力的非线性。新理论基于减少FPK方程的误差以获得参数化的联合概率密度函数。应用本理论易得一维积分表达的系统响应的概率特性,如联合概率密度函数及稳定期望穿阈率。近似解与精确解的比较结果表明:新理论在研究白噪声激励下船舶非线性横摇运动是非常有效的。

关键词： FPK方程白噪声联合概率密度函数稳定期望穿阈率非线性横摇运动

Wake Effects on A Hybrid Semi-Submersible Floating Wind Farm with Multiple Hub Heights

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China Ocean Engineering 2023年第1期37卷 101-114页

作者： XU Xiao-sen gu jia-yang LING Hong-jie YANG Pu-yi WANG Shuai-shuai XING Yi-han Oleg GAIDAI ZHANG Zhong-yu Marine Equipment and Technology Institute Jiangsu University of Science and TechnologyZhenjiang 212100China Department of Mechanical and Civil Engineering Florida Institute of TechnologyMelbourne 32901United States Department of Marine Technology Norwegian University of Science and TechnologyTrondheim 7491Norway Department of Mechanical and Structural Engineering and Materials Science University of StavangerStavanger 4021Norway College of Engineering Science and Technology Shanghai Ocean EngineeringShanghai 201306China

Wind farms generally consist of a single turbine installed with the same hub height. As the scale of turbines increases,wake interference between turbines becomes increasingly significant, especially for floating wind turbines(FWT).Some researchers find that wind farms with multiple hub heights could increase the annual energy production(AEP),while previous studies also indicate that wake meandering could increase fatigue loading. This study investigates the wake interaction within a hybrid floating wind farm with multiple hub heights. In this study, *** is employed to simulate a hybrid wind farm which consists of four semi-submersible FWTs(5MW and 15MW) with two different hub heights. Three typical wind speeds(below-rated, rated, and over-rated) are considered in this paper to investigate the wake meandering effects on the dynamics of two FWTs. Damage equivalent loads(DEL) of the turbine critical components are computed and analyzed for several arrangements determined by the different spacing of the four turbines. The result shows that the dynamic wake meandering significantly affects downstream turbines’ global loadings and load effects. Differences in DEL show that blade-root flapwise bending moments and mooring fairlead tensions are sensitive to the spacing of the turbines.

关键词： hybrid floating wind farm wake meandering multiple hub heights floating wind turbine FAST.Farm fatigue

一种新的路径积分法在船舶横摇概率计算中的应用(英文)

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船舶力学 2006年第6期10卷 43-52页

作者：谷家扬江苏科技大学船舶与海洋工程学院江苏镇江212003

基于Gauss-Legendre积分规则提出了一种新的路径积分法来计算随机横浪中船舶非线性横摇运动的概率密度分布,新的路径积分法能够得出精确的瞬态概率密度分布,包括系统响应尾部区域的概率分布,其对系统的可靠性分析是十分重要的。船舶随... 详细信息

基于Gauss-Legendre积分规则提出了一种新的路径积分法来计算随机横浪中船舶非线性横摇运动的概率密度分布,新的路径积分法能够得出精确的瞬态概率密度分布,包括系统响应尾部区域的概率分布,其对系统的可靠性分析是十分重要的。船舶随机横摇运动微分方程考虑到阻尼力与恢复力的非线性。数值模拟了联合概率密度函数随时间的演变,分析了外部激励强度对船舶稳态概率密度分布的影响。数值模拟的结果表明新的路径积分法对研究船舶非线性横摇运动概率密度分布是十分有效的。

关键词：路径积分法 FPK方程瞬态联合概率密度非线性横摇随机激励

Combining surgery with 125I brachytherapy for recurrent mediastinal dedifferentiated liposarcoma: A case report and review of literature

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World Journal of Clinical Cases 2020年第5期8卷 939-945页

作者： Hui-guo Chen Kai Zhang Wei-Bin Wu Yong-Hui Wu jian Zhang Li-jia gu Xiao-Jun Li Department of Cardiothoracic Surgery the Third Affiliated Hospital of Sun Yat-sen University

BACKGROUND Dedifferentiated liposarcoma in the mediastinum is an extremely rare malignant neoplasm.A few previous case reports indicate that surgical resection is the major treatment,but frequent recurrence occurs *** to its rarity,its clinical characteristics,optimal treatment and clinical outcomes remain ***,we report a case of multifocal recurrent dedifferentiated liposarcoma in the posterior mediastinum treated by combining surgery with 125I brachytherapy,and summarize its clinical features,treatment and *** SUMMARY A 75-year-old man was admitted to our hospital with a history of gradual dysphagia for one year and aggravated dysphagia for 3 ***-enhanced computed tomography(CT)revealed several large cystic-solid masses with lipomatous density,and calcification in the posterior-inferior *** patient received a wide excision by video-assisted thoracoscopic *** analysis confirmed the tumors were dedifferentiated *** tumor locally relapsed 24 mo later,and another operation was performed by video-assisted thoracoscopic *** months after the second surgery,the tumor recurred again,and the patient received CT-guided radioactive seeds 125I *** 8 mo,follow-up chest CT showed an enlarged ***,his condition exacerbated with severe dysphagia and dyspnea,and he died of respiratory failure in July *** We reviewed the literature,and suggest that surgical resection provides beneficial effects for dedifferentiated liposarcoma in the mediastinum,even in cases with local recurrence.125I brachytherapy may be beneficial for recurrent unresectable patients.

关键词： Dedifferentiated liposarcoma Mediastinal neoplasms Recurrence Reoperation 125I brachytherapy Case report

Microstructure and mechanical properties of lightweight AlCrTiV_(0.5)Cu_(x) high-entropy alloys

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Rare Metals 2022年第6期41卷 2016-2020页

作者： Zhen Peng Zai-Bin Luo Bao-Wei Li Jin-Feng Li Heng-Wei Luan jia-Lun gu Yuan Wu Ke-Fu Yao School of Materials Science and Engineering Jiangsu Uni versityZhenjiang 212013China Institute of Materials China Academy of Engineering PhysicsMianyang 621908China School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Department of Mechanical Engineering City University of Hong KongHong Kong 999077China State Key Laboratory for Advanced Metals and Materials.University of Science and Technology Beijing Beijing 100083China

High-entropy alloys(HEAs)are an emerging and rapidly developing family of alloys with appealing properties such as lightweight HEAs with excellent mechanical *** this study,to obtain lightweight HEAs with exceptional hardness,we prepared AlCrTiV_(0.5)Cu_(x)(x=0,0.2,0.4,0.6,0.8 and 1.0,denoted as Cu_(0),Cu_(0.2),Cu_(0.4),Cu_(0.6),Cu_(0.8) and Cu_(1.0) alloys,respectively)HEAs and analyzed their microstructure and hardness.

关键词： alloys properties. Microstructure

Characteristics of LDPE and Oriented Montmorillonite Nanocomposites Produced by Electric Field-inducement

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高电压技术 2013年第8期39卷 1947-1951页

作者： BAI Ge LIAO Ruijin YANG Lijun YUAN Yuan gu jia State Key Laboratory of Transmission & Distribution Equipments and Power System Safety and New Technology Chongqing University Chongqing 400030 China

In order to make montmorillonite (MMT) nanosheets disperse in low-density polyethylene (LDPE) with highly homogeneous orientation, alternating voltage is applied to molten LDPE with MMT nanosheets. The effect of electric field on the dispersion of MMT in the solidified LDPE is studied. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses suggest that the MMT nano- sheets are aligned with high anisotropy to the electric field direction, which is perpendicular to the LDPE film plane. Differential scanning calorimetry (DSC) results reveal that the crystallization degree of the oriented LDPE/MMT composite increases. Moreover, through a broadband dielectric spectroscopy analyzer, it is found that MMT manifests a significantly influence in the dielectric property of the oriented composite: the dielectric constant and loss tangent of the composite both become larger. Analysis shows that the electric field-induced torque caused by the polarization of MMT flakes is the main force inducing the orientation of the MMT flakes.

关键词：纳米复合材料 LDPE薄膜电场方向介电特性蒙脱土低密度聚乙烯扫描电子显微镜差示扫描量热法