检索结果-南通市图书馆

不同表面处理方式影响牙骨质粘接效果的研究进展

在线全文

学校读者我要写书评

暂无评论

口腔颌面修复学杂志 2023年第3期24卷 229-234页

作者：冯杭都陈建治浙江中医药大学口腔医学院杭州310051 浙江树人大学树兰国际医学院附属树兰杭州医院杭州310022

复合树脂粘接修复术是治疗龈下龋及根面龋的主要方法。牙骨质作为颈部粘接边缘,在修复过程中,为避免微渗漏产生及细菌侵入,与修复体的紧密粘接尤为重要。同时,牙骨质受其组成及结构等因素影响,致其粘接性能不佳。为提高牙骨质粘接性能,... 详细信息

复合树脂粘接修复术是治疗龈下龋及根面龋的主要方法。牙骨质作为颈部粘接边缘,在修复过程中,为避免微渗漏产生及细菌侵入,与修复体的紧密粘接尤为重要。同时,牙骨质受其组成及结构等因素影响,致其粘接性能不佳。为提高牙骨质粘接性能,近来有研究对牙骨质表面进行Er,Cr:YSGG激光、Er:YAG激光、柠檬酸、EDTA等特殊处理以改变其表面形貌,进而期待粘接效果的提升。本文就此对牙骨质的理化特征、不同处理方式,粘接剂的选择三方面对牙骨质粘接性能的影响展开论述,为进一步探索牙骨质表面最佳处理方式提供参考。

关键词：牙骨质处理方法粘接性能

基于改进时间信息融合模型的液压管路故障诊断研究

在线全文

学校读者我要写书评

暂无评论

机电工程 2023年第12期40卷 1923-1930页

作者：高鹏李开泰王雷雷窦航江俊松淄博市技师学院智能制造工程系山东淄博255000 东北大学机械工程与自动化学院辽宁沈阳110819 东南大学机械工程学院江苏南京210096

航空发动机液压管路故障信号中存在强大的噪声干扰,导致其诊断模型的故障识别率较低和诊断模型的泛化性不强。针对这一问题,提出了一种基于改进的时间信息融合模型的航空液压管路故障诊断方法。首先,基于循环神经网络原理,设计了正向和... 详细信息

航空发动机液压管路故障信号中存在强大的噪声干扰,导致其诊断模型的故障识别率较低和诊断模型的泛化性不强。针对这一问题,提出了一种基于改进的时间信息融合模型的航空液压管路故障诊断方法。首先,基于循环神经网络原理,设计了正向和反向的时间信息融合的变形结构,构建出了航空液压管路时间信息融合模型,并通过引入LeakyReLU函数,对模型进行了改进;然后,将实测的一维航空管路时序数据集输入到改进的时间信息融合模型双向循环神经网络(Bi-RNN)中,进行了权重参数的更新;最后,基于同一实测的数据集,分别将其输入到改进的时间信息融合模型、长短期记忆神经网络(LSTM)、循环神经网络(RNN)、支持向量机(SVM)和反向传播神经网络(BPNN)5种故障诊断方法中,进行了训练和对比分析,对相关方法的优越性进行了验证。研究结果表明:利用改进的时间信息融合模型可以对液压管路健康状态和裂纹、凹坑等故障状态进行精准识别,并且准确率可以达到99.2%,总体的准确率和综合指标F 1-sore均可以提高5.1%;在综合性能、准确精度等指标上,改进时间信息融合模型明显优于其他故障诊断模型,可为航空发动机液压管路故障诊断提供一条新的思路,具有一定的工程应用价值。

关键词：液压传动回路时间信息融合模型航空管路循环神经网络 LeakyReLU函数权重参数更新

在线全文

学校读者我要写书评

暂无评论

山羊重复手术收集胚胎防止粘连方法比较

中国兽医杂志 2012年第2期48卷 9-12页

作者：权富生张亨德黄欣赵晓娥张涌窦航西北农林科技大学动物医学院陕西杨凌712100 农业部动物生殖生理与胚胎工程重点开放实验室陕西杨凌712100 杨凌科元克隆股份有限公司陕西杨凌712100

山、绵羊重复超排和重复手术收集胚胎后生殖系统等易发生粘连,影响供体重复利用率和胚胎移植效率。本研究以波尔山羊作为供体,应用不同的防粘连方案进行供体重复超排采卵后预防粘连效果的比较,以筛选有效的预防粘连方法。采用32%右旋糖... 详细信息

山、绵羊重复超排和重复手术收集胚胎后生殖系统等易发生粘连,影响供体重复利用率和胚胎移植效率。本研究以波尔山羊作为供体,应用不同的防粘连方案进行供体重复超排采卵后预防粘连效果的比较,以筛选有效的预防粘连方法。采用32%右旋糖酐+肝素(试验组1)和医用几丁糖(试验组2)作为两个试验组,生理盐水冲洗法作为对照组。波尔山羊供体母羊连续超排4次,并重复手术采卵,用不同的防粘连剂进行术后处理比较。结果表明,试验组2使用几丁糖防粘连处理后,供体母羊第4次手术收集胚胎后粘连率只有37.5%,而试验组1和对照组粘连率为100%。使用防粘连剂对于供体母羊的超排效果及可用母羊的胚胎回收率无影响,但是显著提高了供体母羊的超排利用率。应用医用几丁糖防粘连的方法可以有效减少供体母羊的术后粘连率及有效提高供体母羊重复利用率。

关键词：胚胎移植重复超排重复手术抗粘连处理波尔山羊

添加VB12、VE、VC对无角道塞特绵羊精液冷冻效果的影响

在线全文

学校读者我要写书评

暂无评论

西北农业学报 2010年第11期19卷 13-17页

作者：权富生黄欣马会明邓志诚王立华窦航西北农林科技大学动物医学院农业部家畜生殖生理与胚胎工程重点开放实验室陕西杨凌712100 杨凌科元克隆股份有限公司陕西杨凌712100

探讨在无角道塞特绵羊冷冻精液稀释液中添加VB12、VE、VC对精子冷冻品质的影响。在无角道塞特绵羊冷冻精液稀释液中添加不同质量浓度的VB12、VE、VC制作细管冻精,解冻后观察精子的成活率和顶体完整率等指标。结果显示,VB12添加0.003 g/... 详细信息

探讨在无角道塞特绵羊冷冻精液稀释液中添加VB12、VE、VC对精子冷冻品质的影响。在无角道塞特绵羊冷冻精液稀释液中添加不同质量浓度的VB12、VE、VC制作细管冻精,解冻后观察精子的成活率和顶体完整率等指标。结果显示,VB12添加0.003 g/L时能够显著提高解冻后的精子活率(P<0.05)和精子顶体完整率(P<0.05);VE添加2.5 g/L时,能够极显著提高解冻后的精子活率(P<0.01)和顶体完整率(P<0.01);VC的添加4.4 g/L时能够显著提高解冻后的精子活率(P<0.05),但对冷冻后精子的顶体完整率无影响。在稀释液中添加VB12、VE和VC能使解冻后精子品质得到提高。VE添加后能够极显著提高冷冻精子的顶体完整率,应该优先考虑添加。

关键词：细管冻精 VB12 VE VC 无角道塞特绵羊

Monkeypox virus:past and present

在线全文

学校读者我要写书评

暂无评论

World Journal of Pediatrics 2023年第3期19卷 224-230页

作者： Ya-Mei dou hang Yuan Hou-Wen Tian NHC Key Laboratory of Medical Virology and Viral Disease Chinese Center for Disease Control and PreventionNational Institute for Viral Disease Control and Prevention155 Changbai RoadChangPing DistrictBeijing 102206China

Background The objective of this paper is to analyze the current status of monkeypox *** the face of this public health threat,our purpose is to elucidate the clinical characteristics and epidemiology of monkeypox,the developmental progress of monkeypox-related drugs and the vaccines *** sources The literature review was performed in databases including PubMed,Science Direct and Google Scholar up to July *** Since May 2022,the World Health Organization has reported more than 45,000 confirmed cases from 92 nonendemic countries,including nine *** some women and children have been infected so far,most cases have occurred among men who have sex with other men,especially those with multiple sexual partners or anonymous *** Pediatric monkeypox infection has been associated with a higher likelihood of severe illness and mortality than in *** monkeypox illness in pediatrics often requires adjunctive antiviral *** is crucial for all countries to establish sound monitoring and testing systems and be prepared with emergency preparedness.

关键词： Monkeypox Orthopoxvirus Smallpox Zoonotic

Optimized strain performance in <001>-textured Bi_(0.5)Na_(0.5)TiO_(3)-based ceramics with ergodic relaxor state and core-shell microstructure

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2022年第10期11卷 1542-1558页

作者： Xuefan ZHOU Huiping YANG Guoliang XUE hang LUO dou Zhang Powder Metallurgy Research Institute Central South UniversityChangsha 410083China

Herein,a high strain of ~0.3% with a small hysteresis of 43% is achieved at a low electric field of 4 kV/mm in the highly -textured 0.97(0.76Bi_(0.5)Na_(0.5)TiO_(3)-0.24SrTiO_(3))-0.03NaNbO_(3)(BNT-ST-0.03NN)ceramics with an ergodic relaxor(ER)state,leading to a large normalized strain(d_(33)^(*))of 720 pm/*** introduction of NN templates into BNT-ST induces the grain orientation growth and enhances the *** highly -textured BNT-ST-0.03NN ceramics display a pure ergodic relaxor state with coexisted ferroelectric R3c and antiferroelectric P4bm polar nanoregions(PNRs)on ***,due to the incomplete interdiffusion between the NN template and BNT-ST matrix,the textured ceramics present a core-shell structure with the antiferroelectric NN core,and thus the BNT-based matrix owns more R3c PNRs relative to the homogeneous nontextured *** high crystallographic texture and more R3c PNRs both facilitate the relaxor-to-ferroelectric transition,leading to the low-field-driven high strain,while the ergodic relaxor state ensures a small ***,the d_(33)^(*)value remains high up to 518 pm/V at 100℃ with an ultra-low hysteresis of 6%.

关键词： Bi_(0.5)Na_(0.5)TiO_(3)(BNT)-based ceramics ergodic relaxor(ER)state crystallographic texture core-shell structure optimized strain performance

Effect of Unit Cell Shape on Switchable Infrared Metamaterial VO_(2)Absorbers/Emitters

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research 2021年第1期2021卷 994-1001页

作者： Feifei Ren Jinxin Gu hang Wei Gaoping Xu Jiupeng Zhao Shuliang dou Yao Li 1 Center for Composite Materials and Structure Harbin Institute of TechnologyHarbin 150001China School of Chemistry and Chemical Engineering Harbin Institute of TechnologyHarbin 150001China

Metamaterial absorber/emitter is an important aspect of infrared radiation *** this paper,we proposed four simple switchable infrared metamaterial absorbers/emitters with Ag/VO_(2)disks on the Ag plane employing triangle,square,hexagon,and circle unit *** spectral absorption peaks whose intensities are above 0.99 occur at~4μm after structure optimization when VO_(2)is in insulating state and disappear when VO_(2)becomes metallic *** simulated electromagnetic field reveals that the spectral absorption peaks are attributed to the excitation of magnetic polariton within the insulating VO_(2)spacer layer,whose values exceed 1.59 orders of magnitude higher than the incident magnetic *** resonant wavelength would be excited in square arrays because its configuration is a better carrier of charges at the same *** absorption stability,the absorbers/emitters with square and circular structures do not have any change with the polarization angles changing from 0°to 90°,due to the high rotational symmetric *** four absorbers/emitters reveal similar shifts and attenuations under different incident *** believed that the switchable absorber/emitter demonstrates promising applications in the sensing technology and adaptive infrared system.

关键词： emitter polarization absorber

Graphene oxide/gallium nanoderivative as a multifunctional modulator of osteoblastogenesis and osteoclastogenesis for the synergistic therapy of implant-related bone infection

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Bioactive Materials 2023年第7期25卷 594-614页

作者： Ying Yang Min Li Bixia Zhou Xulei Jiang dou Zhang hang Luo Department of Plastic Surgery Xiangya HospitalCentral South UniversityChangsha410008China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha410083China Department of Oncology Changsha Central HospitalUniversity of South ChinaChangsha410006China National Clinical Research Center for Geriatric Disorders Xiangya HospitalCentral South UniversityChangsha410008China

Currently,implant-associated bacterial infections account for most hospital-acquired infections in patients suffering from bone fractures or *** osseointegration and aggravated osteolysis remain great challenges for the success of implants in infectious ***,developing an effective surface modification strategy for implants is urgently ***,a novel nanoplatform(GO/Ga)consisting of graphene oxide(GO)and gallium nanoparticles(GaNPs)was reported,followed by investigations of its in vitro antibacterial activity and potential bacterium inactivation mechanisms,cytocompatibility and regulatory actions on osteoblastogenesis and *** addition,the possible molecular mechanisms underlying the regulatory effects of GO/Ga nanocomposites on osteoblast differentiation and osteoclast formation were ***,an in vivo infectious microenvironment was established in a rat model of implant-related femoral osteomyelitis to determine the therapeutic efficacy and biosafety of GO/Ga *** results indicate that GO/Ga nanocomposites with excellent antibacterial potency have evident osteogenic potential and inhibitory effects on osteoclast differentiation by modulating the BMP/Smad,MAPK and NF-κB signaling *** in vivo experiments revealed that the administration of GO/Ga nanocomposites significantly inhibited bone infections,reduced osteolysis,promoted osseointegration located in implant-bone interfaces,and resulted in satisfactory *** summary,this synergistic therapeutic system could accelerate the bone healing process in implant-associated infections and can significantly guide the future surface modification of implants used in bacteria-infected environments.

关键词： Nanocomposites Antimicrobial potency Implant-associated bone infections Osteogenesis Osteoclastogenesis

Multiple Effects Tailoring the Self-organization Behaviors of Triphenylene Side-chain Liquid Crystalline Polymers via Changing the Spacer Length

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2018年第8期36卷 960-969页

作者： Xiang-Hui Han Xi-Wen Yang Sheng Chen hang Luo dou Zhang Hai-Liang Zhang Key Laboratory of Polymeric Materials and Application Technology of Hunan Province Key Laboratory of Advanced Functional Polymer Materials of Colleges and Universities of Hunan ProvinceCollege of ChemistryXiangtan University State Key Laboratory of Powder Metallurgy Central South University

Long-alkyl tail triphenylene （TP） side-chain liquid crystalline polymers （SCLCPs） with different spacer length （P-m-TP, m = 2, 3, 4, 6, 8, which is the number of carbon atom in the flexible alkyl spacers） have been successfully synthesized via free radical polymerization. The differential scanning calorimetry （DSC）, polarized light microscopy （POM）, ultraviolet-visible spectroscopy （UV- Vis）, wide-angle X-ray diffraction （WAXD） and small-angle X-ray scattering （SAXS） measurements were performed to investigate the influence of multiple effects on the self-organization behaviors of P-m-TP, including steric effect, decoupling effect and π-π stacking effect. The experimental results revealed that P-m-TP （m = 2, 3, 4） formed the columnar phase which was developed by the TP moieties and the main chain as a whole, suggesting that the side-chains had strong steric effect even though the number of spacer length （m） exceeded 4. In addition, the clearing points （Tis） of the polymers were above 300 ℃. When m = 6 and 8, the polymers displayed hexagonal columnar phase and exhibited the low Tis （91 and 80 ℃ respectively）, originating from the self-assembly of triphenylene due to the decoupling effect and π-π stacking effect. This work offers a viable and inspiring pathway to control the phase transition temperature and phase structure ofTP SCLCPs via simply tailoring the spacer length and increasing the alkyl tail length of TP.

关键词： Polymer synthesis Side-chain liquid crystalline polymers Phase structure Steric effect