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Tough Polyion Complex Hydrogel Films of Natural Polysaccharides

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Chinese Journal of Polymer Science 2017年第10期35卷 1276-1285页

作者： feng-bo zhu Hai-chao Yu Wen-xi Lei Ke-feng Ren Jin Qian 吴子良 Qiang Zheng Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province Department of Engineering Mechanics Zhejiang University Ministry of Education Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering Zhejiang University

The developments of tough hydrogels in recent years have greatly expanded the applications of hydrogels as structural materials. However, most of the tough hydrogels are made of synthetic polymers. To develop biopolymer-based tough hydrogels has both fundamental and practical significances. Here we report a series of polysaccharides-based tough hydrogel films prepared by polyion complexation and solvent evaporation of chondroitin sulfate（CS） and protonated chitosan（CHT） solutions with different weight ratios. The obtained CS/CHT gel films with thickness of 40-80 μm and water content of 66 wt%-81 wt% possess excellent mechanical properties, with tensile breaking stress and breaking strain being 0.4-3 MPa and 160%-320%, respectively. We found that in the mixture solutions there are large amounts of excess CHT in terms of charges; after swelling the films in water, the acetic acid, which is used to protonate the amino groups of CHT, diffuses out of the gel matrix, enhancing the intermolecular interactions between CHT molecules and thus improving the mechanical properties of gel films, besides the ionic bonds between CS and CHT. Antimicrobial tests also showed that the gel films with low weight ratio of CS to CHT, corresponding to the case with excess CHT, have evident antimicrobial effect. These CS/CHT gel films with good mechanical properties and antimicrobial effect should extend the applications of hydrogels in biomedical fields.

关键词： responsive polymerization methacrylate acrylamide hydrophilic reversible dissipation AMPS toughness swelling

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介电高弹体的材料、结构和器件力学（英文）

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2016年第1期17卷 1-21页

作者： feng-bo zhu Department of Engineering Mechanics Zhejiang UniversityHangzhou 310027China Soft Matter Research Center Zhejiang UniversityHangzhou 310027China Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province Zhejiang UniversityHangzhou 310027China

目的:介电高弹体是典型电敏性材料,在外加电场的作用下会产生大的变形,这一特点使其成为人工肌肉致动的理想材料,近年来引起研究者的广泛关注。本文着重介绍介电高弹体的基本力学理论和方法,旨在为相关材料、结构和器件的设计提供参考,... 详细信息

目的:介电高弹体是典型电敏性材料,在外加电场的作用下会产生大的变形,这一特点使其成为人工肌肉致动的理想材料,近年来引起研究者的广泛关注。本文着重介绍介电高弹体的基本力学理论和方法,旨在为相关材料、结构和器件的设计提供参考,也有助于不同专业背景的研究者了解并开展介电高弹体的相关研究。概要:本文介绍了近年来关于介电高弹体力电耦合问题的一些理论和数值研究,重点包括力电耦合的控制方程、材料本构关系、粘弹性响应、力电失稳以及致动器设计等方面。文中讨论了基于非平衡热动力学的介电高弹体力学模型处理复杂构型或与时间相关变形时常被采用的数值方法,优化介电高弹体致动极限的力学设计,以及介电高弹体力电响应在典型致动器中的应用。

关键词：人工肌肉智能材料介电高弹体力电耦合本构关系粘弹性力电失稳致动

Age and Growth Characteristics of Crimson Sea Bream Paragyrops edita Tanaka in Beibu Gulf

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Journal of Ocean University of China 2008年第4期7卷 457-465页

作者： HOU Gang feng bo LU Huosheng zhu Junfeng Fisheries College Guangdong Ocean University Zhanjiang 524025 P. R. China

Age and growth characteristics of crimson sea bream Paragyrops edita Tanaka in Beibu Gulf were studied through bottom trawling and gillnet fleets fishing from July 2006 to December 2007. A total number of 1155 individuals, ranging from 49 to 249mm in standard length was examined. The age of the fish was determined from sagittal otoliths. One year growth was made up of one translucent and one opaque zone. A maximum likelihood estimation procedure was used to fit the Von Bertalanffy, Logistic and Gompertz growth functions to the length-at-age data. ARSS indicated that there were no significant differences in growth between sexes in the three growth models （P〉0.05）, and the Von Bertalanffy growth function Lr=292.8{1 cxp[-0.167（t＋1.l16）]} was selected as the most appropriate growth model according to Akaike＇s information criterion （AIC）.

关键词： Paragyrops edita Tanaka growth function sagittal otolith maximum likelihood estimation Beibu Gulf

A Unified Model Fusing Region of Interest Detection and Super Resolution for Video Compression

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Computers, Materials & Continua 2024年第6期79卷 3955-3975页

作者： Xinkun Tang feng Ouyang Ying Xu Ligu zhu bo Peng School of Computer and Cyber Sciences Communication University of ChinaBeijing100024China Cable Television Technology Research Institute Academy of Broadcasting ScienceBeijing100866China

High-resolution video transmission requires a substantial amount of *** this paper,we present a novel video processing methodology that innovatively integrates region of interest(ROI)identification and super-resolution *** method commences with the accurate detection of ROIs within video sequences,followed by the application of advanced super-resolution techniques to these areas,thereby preserving visual quality while economizing on data *** validate and benchmark our approach,we have curated a new gaming dataset tailored to evaluate the effectiveness of ROI-based super-resolution in practical *** proposed model architecture leverages the transformer network framework,guided by a carefully designed multi-task loss function,which facilitates concurrent learning and execution of both ROI identification and resolution enhancement *** unified deep learning model exhibits remarkable performance in achieving super-resolution on our custom *** implications of this research extend to optimizing low-bitrate video streaming *** selectively enhancing the resolution of critical regions in videos,our solution enables high-quality video delivery under constrained bandwidth *** results demonstrate a 15%reduction in transmission bandwidth compared to traditional super-resolution based compression methods,without any perceivable decline in visual *** work thus contributes to the advancement of video compression and enhancement technologies,offering an effective strategy for improving digital media delivery efficiency and user experience,especially in bandwidth-limited *** innovative integration of ROI identification and super-resolution presents promising avenues for future research and development in adaptive and intelligent video communication systems.

关键词： Super resolution region of interest detection video compression

Parking choice behaviour analysis of rural residents based on the latent variable random forest model

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Transportation Safety and Environment 2024年第3期6卷 167-180页

作者： Minqing zhu bo Zhao Hongjun Cui Sheng Yao feng Xu School of Architecture and Art Design Hebei University of TechnologyTianjin 300130China School of Civil and Transportation Engineering Hebei University of TechnologyTianjin 300401China

The imbalance of rural parking supply and demand has a great impact on traffic congestion and environmental pollution,which has attracted the attention of many scholars as well as ***,most of the current research on parking choice focuses on urban business and residential areas rather than on rural parking choice behaviour,and focuses on the analysis of observable factors,ignoring the internal relationship with potential *** study considers the heterogeneity of individuals and uses the random forest(RF)algorithm to construct a model of rural residents’willingness to choose parking with both latent and explicit variables,to explore how much and in what ways individual characteristics and parking characteristics affect rural residents’parking choices,and to explore parking planning programmes and strategies that are truly applicable to rural *** results of the study suggest that the safety and convenience of the parking environment are key factors influencing the parking choice behaviour of rural residents,and can greatly improve the predictive accuracy of the parking willingness *** comparison,it is found that the application of the RF algorithm is also significantly better than the logit model in terms of prediction effect,indicating that there is a nonlinear effect among the factors influencing the parking choice behaviour of rural residents and that the RF model with the addition of latent variables provides a better explanatory ability for the study of the parking choice behaviour of rural residents.

关键词： rural residents parking choice random forest(RF) latent variable SEM-RF model

Numerical simulation of melt flow and temperature field during DC casting 2024 aluminium alloy under different casting conditions

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China Foundry 2024年第4期21卷 387-396页

作者： Jin-chuan Wang Yu-bo Zuo Qing-feng zhu Jing Li Rui Wang Xu-dong Liu Key Laboratory of Electromagnetic Processing of Materials Ministry of EducationNortheastern UniversityShenyang 110819China School of Materials Science and Engineering Northeastern UniversityShenyang 110819China Engineering Research Center of Advanced Materials Preparing Technology Ministry of EducationShenyang 110819China CAS Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

Casting speed,casting temperature and secondary cooling water flow rate are the main process parameters affecting the DC casting *** parameters significantly influence the flow and temperature fields during casting,which are crucial for the quality of the ingot and can determine the success or failure of the casting *** simulation,with the advantages of low cost,rapid execution,and visualized results,is an important method to study and optimize the DC casting *** the present work,a simulation model of DC casting 2024 aluminum alloy was established,and the reliability of the model was ***,the influence of casting parameters on flow field and temperature field was studied in detail by numerical simulation *** show that with the increase of casting speed,the melt flow becomes faster,the depths of slurry zone and mushy zone increase,and the variation of slurry zone depth is greater than that of mushy *** an increase in casting temperature,the melt flow rate increases,the depth of the slurry zone becomes shallower,and the depth of the mushy zone experiences only minor *** simulation results further indicate that the increase of the flow rate of the secondary cooling water slightly reduces the depths of both slurry and mushy zone.

关键词： aluminium DC casting flow field temperature field numerical simulation

A novel method for AFRPs burrs removal:Principle of mechanochemo-induced fiber fracture

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Chinese Journal of Aeronautics 2024年第7期37卷 522-538页

作者： Jie XU bo LI Pingfa feng Qiang WANG feng feng Division of Advanced Manufacturing Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055China Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China Changhe Aircraft Industry(Group)Co.Ltd Jingdezhen 333000China

Burrs generated during the machining of Aramid-Fiber-Reinforced Composites(AFRPs)pose a challenge for the production efficiency of aircraft and helicopter housing *** studies have generally attempted to suppress burrs by referring to delamination suppression *** contrast to stratification,burrs are remediable machining *** such,a mechanochemical method with burrs trimming technological strategy are implemented to effectively combat ***,we clarify the mechanism by which aramid fibers cannot be cut off using analytical and numerical *** addition,the mechanism of fiber fracture with Modified Polyurethane Reactive Polymer(M-PUR),and development of anti-burr devices(thermostatic adhesive sealed generator)are ***,the experimental results show that the reduction rate in burr length is 87%-91%through the mechanochemical *** method not only opens a new avenue to solve the burr problem of aramid fibers but also builds an interdisciplinary bridge between polymer science and composite machining.

关键词： Mechanochemical method Burrs Orthogonal cutting Aramid fiber-reinforced composites Milling

Relationships between endothelial nitric oxide synthase gene polymorphisms and osteoporosis in postmenopausal women

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2009年第8期10卷 609-618页

作者： Shun-zhi LIU Hong YAN Wei-kun HOU Peng XU Juan TIAN Li-fang TIAN bo-feng zhu Jie MA She-min LU Department of Public Health School of Medicine Xi 'an Jiaotong University Xi 'an 710061 China Key Laboratory of Environment and Genes Related to Diseases of Ministry of Education Xi 'an Jiaotong University Xi 'an 710061 China Department of Genetics and Molecular Biology School of Medicine Xi 'an Jiaotong University Xi 'an 710061 China Department of bone and Joint Diseases of Xi 'an Red Cross Hospital Xi 'an 710054 China Department of Forensic Medicine School of Medicine Xi 'an Jiaotong University Xi'an 710061 China

Objective： To investigate the relationships between endothelial nitric oxide synthases （eNOS） G894T and 27 bpvariable number tandem repeat （VNTR） gene polymorphisms and osteoporosis in the postmenopausal women of Chinese Han nationality. Methods： In the present study, 281 postmenopausal women from Xi＇an urban area in West China were recruited, and divided into osteoporosis, osteopenia, and normal groups according to the diagnostic criteria of osteoporosis proposed by World Health Organization （WHO）. The bone mineral density （BMD） values of lumbar vertebrae and left hips were determined by QDR-2000 dual energy X-ray absorptiometry. Blood samples were tested for plasma biochemical indicators including testosterone, estradiol, calcitonin, osteocalcin, and procollagen type I amino-terminal propeptide by enzyme-linked immunosorbent assay （ELISA）, tartrate-resistant acid phosphatase by spectrophotometric method, and the content of nitric oxide by Griess method. Genome DNA was extracted from whole blood, and G894T polymorphism of eNOS gene was analyzed by using polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） method and 27 bp-VNTR polymorphism of eNOS gene was genotyped by PCR method. Then the relationships between genotypes and biochemical indicators, genotypes and osteoporosis, and haplotypes and osteoporosis were analyzed. Results： The average BMD values of the femoral neck, ward＇s triangle and lumbar vertebrae 1-4 （LI-L4） in the subjects with T/T genotype in eNOS G894T locus were significantly higher than those in the subjects with G/T and G/G genotypes （P〈0.05）. The average BMD of the femoral neck in the subjects with a/a genotype of eNOS 27 bp-VNTR locus was evidently higher than that in the subjects with b/b genotype （P〈0.05）. The plasma testosterone and osteocalcin concentrations in the subjects of eNOS G894T G/T genotype were evidently higher than those in the subjects of other genotypes （P〈0.05）; the plasma estradiol concentration in

关键词： Postmenopausal women Osteoporosis Endothelial nitric oxide synthase Gene polymorphisms bone mineral density

Magnetic resonance imaging of knees:a novel approach to predict recombinant human growth hormone therapy response in short-stature children in late puberty

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World Journal of Pediatrics 2024年第7期20卷 723-734页

作者： Xi Bai Zhi‑bo Zhou Xiao‑Yuan Guo Yi‑Ling He Yue‑Lun Zhang feng‑Dan Wang feng feng Hong‑bo Yang Shi Chen feng‑Ying Gong Hui‑Juan zhu Hui Pan Department of Endocrinology Shandong Provincial Hospital Affiliated to Shandong First Medical UniversityJinanShandongChina Key Laboratory of Endocrinology of National Health Commission Department of EndocrinologyState Key Laboratory of Complex Severe and Rare DiseasesPeking Union Medical College HospitalChinese Academy of Medical Science and Peking Union Medical CollegeBeijing 100730China Medical Research Center Peking Union Medical College HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina Department of Radiology Peking Union Medical College HospitalChinese Academy of Medical Science and Peking Union Medical CollegeBeijingChina

Background There is no appropriate tool to predict recombinant human growth hormone(rhGH)response before therapy initiation in short-stature children in late *** current study aimed to explore the associations between magnetic resonance imaging(MRI)stages of the knee growth plates and rhGH response in short-stature children in late *** In this prospective cohort study,short-stature children in late puberty were treated with rhGH and followed up for 6 *** proposed a novel knee MRI staging system according to the growth plate states of distal femurs or proximal tibias and divided the participants into three groups:unclosed growth plate group,marginally closed growth plate group,and nearly closed growth plate *** primary outcomes were height gain and growth velocity(GV),which were assessed three months *** Fifty participants were enrolled,including 23 boys and 27 *** and height gain after 6 months of rhGH therapy decreased successively in the three groups with an increased degree of growth plate fusion,especially when grouped by proximal tibias(GV_(1-3 mon)from 9.38 to 6.08 to 4.56 cm/year,GV_(4-6 mon)from 6.75 to 4.92 to 3.25 cm/year,and height gain from 4.03 to 2.75 to 1.95 cm,all P<0.001).Moreover,the MRI stages of growth plates independently served as a significant variable for GV and height gain after therapy,especially when grouped by proximal tibias(all P<0.01).Conclusion The MRI staging method is expected to be an effective tool for predicting rhGH response before therapy initiation in short-stature children in late puberty.

关键词： Growth hormone Growth velocity Late puberty Magnetic resonance imaging Short stature