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China Ocean Engineering 2019年第4期33卷 446-458页

作者： YU Yang-zhe feng Guo-qing li chen-feng REN Hui-long College of Shipbuilding Engineering Harbin Engineering University

The study of the ultimate strength of stiffened plates is a hot topic in ocean engineering. The ultimate strength and behavior of collapse of stiffened plates were investigated using experimental and numerical methods. Two stiffened plates, with one and two half-bays in both longitudinal and transverse directions, were tested under the uniaxial compression. There were clamped boundaries at both ends of the stiffened panels and a restrained boundary on the transverse frames. The novel three-dimensional laser scanning technology was used to measure the initial geometric imperfections and the ultimate deformation of the stiffened panels after the test. The initial geometric deformation was imported into the finite element model, and the ultimate strength and behavior of collapse of the stiffened plates were calculated using the finite element analysis. FE analysis results based on the measured initial geometric imperfections were compared with the test results. It is concluded that structural deformation can be well measured by three-dimensional laser scanning technology, and can be conveniently imported into the finite element analysis. With the measured initial geometric imperfections considered, the FE analysis results agree well with the experimental results in ultimate strength, behavior of collapse, and the ultimate displacement distribution of the stiffened panels.

关键词： Stiffened plate ultimate strength experiment three dimensional laser scanning initial geometric imperfection

Electrophysiological changes of autonomic cells in left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with chronic heart failure

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Asian Pacific Journal of Tropical Medicine 2017年第12期10卷 1197-1200页

作者： ling Fan li-feng chen Jing Fan Department of Hematology The First Affiliated Hospital of Hebei North University Department of Physiology Basic Medical College Hebei North University Department of Obstetrics and Gynecology The Sixth Hospital of Zhangjiakou

Objective: To investigate the electrophysiological changes of autonomic cells in left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with chronic heart ***: Guinea pigs model of iron deficiency anemia complicated with chronic heart failure in 10 guinea pigs of the experimental group was made by feeding a low iron diet,pure water and subcutaneous injection of isoproterenol. The control group consisting of 11 guinea pigs was given normal food, normal water and injected with normal saline. The left ventricular outflow tract model specimen was also prepared. The standard microelectrode technique was used to observe electrophysiological changes of autonomic cells in the outflow tract of left ventricular heart failure complicated with iron deficiency anemia in guinea pig model. The indicators of observation were maximal diastolic potential, action potential amplitude, 0 phase maximal depolarization velocity, 4 phase automatic depolarization velocity, repolarization 50% and 90%, and spontaneous discharge ***: Compared with the control group, 4 phase automatic depolarization velocity,spontaneous discharge frequency and 0 phase maximal depolarization velocity decreased significantly(P litude reduced(P lities of the left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with heart failure.

关键词： Iron deficiency anemia Chronic heart failure Guinea pig model Autonomic cells Left ventricular outflow tract Electrophysiology

Biotemplated synthesis of three-dimensional porous MnO/C-N nanocomposites from renewable rapeseed pollen： An anode material for lithium-ion batteries

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Nano Research 2017年第1期10卷 1-11页

作者： li-feng chen Sheng-Xiang Ma Shu Lu Yue feng Jia Zhang Sen Xin Shu-Hong Yu Division ofNanomatefials & Chemistry Hefei National Laboratory for Physical Sciences at Microscale Collaborative Innovation Center of Suzhou Nano Science and Technology CAS Center for Excellence in Nanoscience Department of Chemistry Department of Materials Science & Engineering University of Science and Technology of China Hefei 230026 China Anhui Key Laboratory of Controllable Chemical Reaction and Material Chemical Engineering School of Chemical Engineering Hefei University of Technology Hefei 230009 China

lithium-ion batteries （liBs） are currently recognized as one of the most popular power sources available. To construct advanced liBs exhibiting long-term endurance, great attention has been paid to enhancing their poor cycle stabilities. As the performance of liBs is dependent on the electrode materials employed, the most promising approach to improve their life span is the design of novel electrode materials. We herein describe the rational design of a three-dimensional （3D） porous MnO/C-N nanoarchitecture as an anode material for long cycle life liBs based on their preparation from inexpensive, renewable, and abundant rapeseed pollen （R-pollen） via a facile immersion-annealing route. Remarkably, the as-prepared MnO/C-N with its optimized 3D nanostructure exhibited a high specific capacity （756.5 mAh·g^-1 at a rate of 100 mA·g^-1）, long life span （specific discharge capacity of 513.0 mAh·g^-1, -95.16% of the initial reversible capacity, after 400 cycles at 300 mA·g^-1）, and good rate capability. This material therefore represents a promising alternative candidate for the high-performance anode of next-generation liBs.

关键词： 3D porous MnO/C-Nnanocomposite rapeseed pollen renewable biomass lithium-ion batter long cycle life

拟人工黑体结构的带隙设计阵列化降噪特性研究

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节能技术 2024年第4期42卷 291-298,305页

作者：杨嘉明许如航李小斌李凤臣天津大学机械工程学院先进内燃动力全国重点实验室天津300350

为了解决噪声污染对人居环境带来的不利影响,基于声子晶体带隙原理,受人工黑体结构启发,提出了拟人工黑体结构的开口管状阵列的带隙降噪结构设计,利用平面波在阵列之间以及管状结构内部的干涉相消达到降噪效果。使用数值模拟和实验研究... 详细信息

为了解决噪声污染对人居环境带来的不利影响,基于声子晶体带隙原理,受人工黑体结构启发,提出了拟人工黑体结构的开口管状阵列的带隙降噪结构设计,利用平面波在阵列之间以及管状结构内部的干涉相消达到降噪效果。使用数值模拟和实验研究的方法,对比分析了不同因素对降噪效果的影响,从晶体阵列排布形式、法向排数及开口角度大小等角度出发,进行了参数化影响因素分析。结果表明,该带隙设计的阵列化结构可有效降低噪声。其中高频段传输损失可达100 dB以上,低频段也可达30~45 dB。该研究对典型场景的降噪需求的设计具有重要参考价值。

关键词：降噪拟人工黑体声子晶体阵列布置带隙设计频谱分析

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Effects of probiotic therapy on hepatic encephalopathy in patients with liver cirrhosis:an updated meta-analysis of six randomized controlled trials

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Hepatobiliary & Pancreatic Diseases International 2014年第4期13卷 354-360页

作者： Jun Xu Rui Ma li-feng chen li-Jun Zhao Kan chen Ren-Bing Zhang Department of Surgery Zhejiang University Hospital Zhejiang University

BACKGROUND： liver cirrhotic patients with hepatic encephalopathy have poor prognosis. Probiotics alter the intestinal microbiota and reduce the production of ammonia. We conducted a meta-analysis about the role of probiotics on liver cirrhotic patients with hepatic *** SOURCES： We collected the relevant literatures up to February 21, 2014 from databases of PubMed, EMBASE and the Cochrane Central Register of Controlled Trials. A statistical analysis was conducted by RevMan 5.2 and STATA 12.0 ***： Six randomized controlled trials involving 496 liver cirrhotic patients were included. The results showed that probiotic therapy significantly reduced the development of overt hepatic encephalopathy（OR [95% CI]： 0.42 [0.26, 0.70],P=0.0007）. However, probiotics did not affect mortality, levels of serum ammonia and constipation（mortality： OR [95% CI]：0.73 [0.38, 1.41], P=0.35; serum ammonia： WMD [95% CI]：-3.67 [-15.71, 8.37], P=0.55; constipation： OR [95% CI]： 0.67 [0.29,1.56], P=0.35）.CONCLUSION： Probiotics decrease overt hepatic encephalopathy in patients with liver cirrhosis.

关键词： probiotics hepatic encephalopathy liver cirrhosis ammonia meta-analysis

The reversible addition-fragmentation chain transfer(RAFT) miniemulsion polymerization of vinyl acetate mediated by xanthate

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Chinese Chemical Letters 2009年第6期20卷 733-737页

作者： Bo Jiang Qing Hua Zhang Xiao li Zhan feng Qiu chen Department of Chemical and Biochemical Engineering Zhejiang University Hangzhou 310027 People's Republic of China

The reversible addition-fragmentation chain transfer （RAFT） miniemulsion polymerization of vinyl acetate （VAc） mediated by methyl （methoxycarbonothioyl） sulfanyl acetate （MMSA） was carried out. The results showed that polymerizations initiated by AIBN and KPS proceeded in a controlled way. The RAFT miniemulsion polymerization of VAc initiated by KPS showed the shorter inhibition period, higher propagation rate coefficient and final conversion than those in experiment initiated by AIBN. When the monomer conversion reached 25%, the polydispersity index （PDI） of polymer became broad, which was related to chain transfer reaction in RAFT miniemulsion of VAc.

关键词： Xinyl acetate Xanthate Reversible addition-fragmentation chain transfer Miniemulsion

Monomer reactivity ratios for fluoroacrylate and butyl methacrylate in miniemulsion copolymerizations initiated by potassium persulphate

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Chinese Chemical Letters 2009年第4期20卷 478-482页

作者： Qing Hua Zhang Zhen Huan Luo Xiao li Zhan feng Qiu chen College of Materials Science and Chemical Engineering Zhejiang University Hangzhou 310027 China

Miniemulsion copolymerization of butyl mathacrylate （BMA） with fluoroacrylate （HFMA, TFMA） was carried out at 70 ℃ by employing potassium persulphate （KPS） as initiator. Copolymer compositions at low conversion levels were determined by ^1H NMR spectra techniques. The reactivity ratios were evaluated by employing Kellen-Tudos （K-T） methods, which yields the apparent reactivity ratios, rBMA = 0.74, rHFMA = 0.87 and rBMA = 0.73, rTFMA = 0.75, respectively, and Q- and e-values of HFMA and TFMA were calculated by the Alfrey-Price method. The results show that HFMA and TFMA are more active than BMA, and the cross-propagation rate constant is greater than the self-propagation one in these two copolymerizations.

关键词： Fluoroacrylate Reactivity ratios Miniemulsion Copolymerization

A Random Fusion of Mix 3D and Polar Mix to Improve Semantic Segmentation Performance in 3D lidar Point Cloud

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 845-862页

作者： Bo liu li feng Yufeng chen School of Computer Science and Engineering Macao University of Science and TechnologyMacao999078China School of Computer Science and Artificial Intelligence Chaohu UniversityChaohu238000China Institute of Vehicle Information Control and Network Technology Hubei University of Automotive TechnologyShiyan442002China

This paper focuses on the effective utilization of data augmentation techniques for 3Dlidar point clouds to enhance the performance of neural network *** point clouds,which represent spatial information through a collection of 3D coordinates,have found wide-ranging *** augmentation has emerged as a potent solution to the challenges posed by limited labeled data and the need to enhance model generalization *** of the existing research is devoted to crafting novel data augmentation methods specifically for 3D lidar point ***,there has been a lack of focus on making the most of the numerous existing augmentation *** this deficiency,this research investigates the possibility of combining two fundamental data augmentation *** paper introduces PolarMix andMix3D,two commonly employed augmentation techniques,and presents a new approach,named *** of using a fixed or predetermined combination of augmentation methods,RandomFusion randomly chooses one method from a pool of options for each instance or *** innovative data augmentation technique randomly augments each point in the point cloud with either PolarMix or *** crux of this strategy is the random choice between PolarMix and Mix3Dfor the augmentation of each point within the point cloud data *** results of the experiments conducted validate the efficacy of the RandomFusion strategy in enhancing the performance of neural network models for 3D lidar point cloud semantic segmentation *** is achieved without compromising computational *** examining the potential of merging different augmentation techniques,the research contributes significantly to a more comprehensive understanding of how to utilize existing augmentation methods for 3D lidar point *** data augmentation technique offers a simple yet effective method to leverage the diversity of augmentation techniques and boost the ro

关键词： 3D lidar point cloud data augmentation RandomFusion semantic segmentation

Honokiol Prevents Intestinal Barrier Dysfunction in Mice with Severe Acute Pancreatitis and Inhibits JAK/STAT1 Pathway and Acetylation of HMGB1

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Chinese Journal of Integrative Medicine 2024年第6期30卷 534-542页

作者： li Jie chen Ya-feng GAO Lei li Yi-jie feng Dian-xu Department of General Surgery Putuo HospitalShanghai University of Traditional Chinese MedicineShanghai200062China

Objective To investigate the effect of honokiol(HON)and the role of high-mobility group protein B1(HMGB1)on the pathogenesis of severe acute pancreatitis(SAP).Methods Thirty mice were numbered according to weight,and randomly divided into 5 groups using a random number table,including control,SAP,SAP and normal saline(SAP+NS),SAP and ethyl pyruvate(SAP+EP),or SAP+HON groups,6 mice in each *** of pancreas,intestine,and blood were collected 12 h after SAP model induction for examination of pathologic changes,immune function alterations by enzyme linked immunosorbent assay(EliSA),and Western *** vitro experiments,macrophages were divided into 5 groups,the control,lipopolysaccharide(LPS),LPS+DMSO(DMSO),LPS+anti-HMGB1 monoclonal antibody(mAb),and LPS+HON *** tight connection level was determined by transmission electron microscopy and fluorescein *** location and acetylation of HMGB1 were measured by Western ***,pyridone 6 and silencing signal transducer and activator of the transcription 1(siSTAT1)combined with honokiol were added to determine whether the Janus kinase(JAK)/STAT1 participated in the regulation of honokiol on *** protein expression levels of HMGB1,JAK,and STAT1 were detected using Western *** Mice with SAP had inflammatory injury in the pancreas,bleeding of intestinal tissues,and cells with disrupted *** in the SAP+HON group had significantly fewer pathological *** with SAP also had significant increases in the serum levels of amylase,lipase,HMGB1,tumor necrosis factor-α,interleukin-6,diamine oxidase,endotoxin-1,and *** in the SAP+HON group did not show these abnormalities(Plity,decreased the levels of junctional adhesion molecule C,and elevated intercellular permeability(P<0.01).HON treatment blocked these *** of

关键词： severe acute pancreatitis intestinal barrier dysfunction honokiol high-mobility group protein B1 Januskinase signal transducerand activatorof transcription1

Effect of Sc on Al_(3)Fe phase and mechanical properties of as-cast AA5052 aluminum alloy

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China Foundry 2024年第3期21卷 257-264页

作者： Yang li Qing Yu feng-feng chen Jia-wen He Hong-mei Yang Meng-nie li Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China

The AA5052 aluminum alloy is widely used in automobile and aerospace manufacturing,and with the development of light-weight alloys,it is required that these materials exhibit better mechanical *** studies have demonstrated that the addition of Sc to aluminum alloys can improve both the microstructure and properties of the *** this study,the effect of Sc on the Fe-rich phase and properties of the AA5052 aluminum alloy was studied by adding 0%,0.05%,0.2%,and 0.3%*** results show that with the increase of Sc,the coarse needle-like Fe-rich phase gradually transforms into Chinese-script and then nearly spherical particles,reduce the size of Fe-rich phase,and refine the grain with increase of high angle grain boundaries(HAGBs).These microstructure changes enhance the strength of the AA5052 alloy through Sc *** ductility of the alloy is obviously improved because the addition of a lower amount of Sc changes the morphology of Fe-rich phase from needle-like into a Chinese-script,and it is subsequently reduced as a result of significant increase in HAGBs with increasing Sc content.

关键词： AA5052 aluminum alloy Al3Fe phase mechanical properties grain boundary