检索结果-内蒙古大学图书馆

Dynamics behavior of homogeneous dielectric barrier discharge at atmospheric pressure

JOURNAL OF APPLIED PHYSICS 2009年第2期106卷 023307-023307-6页

作者： Zhang, Yan Gu, Biao Wang, Wenchun Wang, Dezhen peng, xuwen Dalian Univ Technol State Key Lab Mat Modificat Laser Ion & Elect Bea Dalian 116024 Peoples R China Henan Polytech Univ Sch Mech & Power Engn Henan 454000 Peoples R China Dalian Univ Technol Sch Phys & Optoelect Technol Dalian 116024 Peoples R China

An experimental study on the dynamics behavior of homogeneous dielectric barrier discharge (HDBD) at atmospheric pressure is described in this paper. Two kinds of discharge mode, glow and Townsend discharge modes, can be easily identified according to the differential conductivity of current-voltage relationship in the ascent stage of discharge current for the atmospheric HDBD. A (three-dimensional) 3D phase space made by discharge current, gas gap voltage, and charge density of dielectric-plate surface was utilized in the study. By projecting the discharge evolution trajectory in the 3D space, the 3D trajectory of multiple current peaks discharge in atmospheric helium shows a limited cycle with convolutions and undergoes a series of bifurcation process;however, the 3D trajectory of atmospheric N-2 HDBD is a limited cycle without any convolution and bifurcation process. In addition, the first ionization coefficient of working gas plays a key role to determine the discharge mode of atmospheric HDBD, the transition of discharge mode and the dynamics stability of atmospheric HDBD. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3159881]

关键词： DIELECTRICS ATMOSPHERIC pressure IONIZATION (Atomic physics) HELIUM CONVOLUTIONS (Mathematics) PHASE space (Statistical physics)

来源：评论

学校读者我要写书评

暂无评论

Experimental investigation on large-area dielectric barrier discharge in atmospheric nitrogen and air assisted by the ultraviolet lamp

引用

SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2009年第3期72卷 460-464页

作者： Zhang, Yan Gua, Biao Wang, Wenchun Wang, Dezhen peng, xuwen Dalian Univ Technol State Key Lab Mat Modificat Laser Ion & Electron Dalian 116024 Peoples R China Dalian Univ Technol Sch Phys & Optoelect Technol Dalian 116024 Peoples R China

In this paper, ultraviolet radiation produced by the ultraviolet lamp is employed to supply pre-ionization for the dielectric barrier discharge in N-2 or air at atmospheric pressure. The effect of the ultraviolet preionization on improving the uniformity of the dielectric barrier discharge is investigated experimentally. The atmospheric pressure glow discharge of the large area (270 mm x 120 mm) is obtained successfully via the ultraviolet pre-ionization in atmospheric DBD in N-2 when the gas gap decrease to 3 mm. Based on the emission spectra, the mechanism which ultraviolet pre-ionization improves the uniformity of the dielectric barrier discharge is discussed. (c) 2008 Elsevier B.V. All rights reserved.

关键词： Pre-ionization Ultraviolet lamp Emission spectra Dielectric barrier discharge Atmospheric pressure

来源：评论

学校读者我要写书评

暂无评论

Recent Advances in Mechano-Responsive Hydrogels for Biomedical Applications

引用

ACS APPLIED POLYMER MATERIALS 2020年第3期2卷 1092-1107页

作者： Chen, Jingsi peng, Qiongyao peng, xuwen Han, Linbo Wang, Xiaogang Wang, Jianmei Zeng, Hongbo Univ Alberta Dept Chem & Mat Engn Edmonton AB T6G 1H9 Canada Shenzhen Technol Univ Coll Hlth Sci & Environm Engn Shenzhen 518118 Peoples R China Taiyuan Univ Sci & Technol Heavy Machinery Engn Res Ctr Educ Minist Taiyuan 030024 Peoples R China

Mechanical responsiveness is prevalent in biological systems and plays an essential role in many biomechanical processes. The past two decades have witnessed enormous effort devoted to the development of biomimetic mechano-responsive hydrogels which are capable of adapting their physical and chemical properties to external mechanical stimuli. Due to the combination of tissue similarity and mechano-responsive properties, this type of hydrogel offers great advantages for diverse biomedical applications. Strain-stiffening and self-healing hydrogels duplicate the physiological properties of biological tissues, serving as promising candidates for artificial tissues, tissue scaffolds, and wound dressings. The shear-thinning property provides the hydrogels injectability, and the regional delivery contributes to minimally invasive treatment. Mechanochromic hydrogels allow the direct visualization of mechanical stress, holding great promise in biosensing and diagnosing. This review highlights the most recent developments in mechano-responsive hydrogels with various applications in the biomedical field. Different types of mechano-responsive hydrogels are introduced with focus on their responsive mechanisms, design strategies, and in vitro/in vivo performances, providing useful insights into the understanding and future research directions of mechano-responsive hydrogels with applications in biomedical engineering.

关键词： mechano-responsive hydrogel strain-stiffening self-healing shear-thinning mechanochromic

来源：评论

学校读者我要写书评

暂无评论

Adhesive Coacervates Driven by Hydrogen-Bonding Interaction

引用

SMALL 2020年第43期16卷 2004132-2004132页

作者： peng, Qiongyao Chen, Jingsi Zeng, Zicheng Wang, Tao Xiang, Li peng, xuwen Liu, Jifang Zeng, Hongbo Univ Alberta Dept Chem & Mat Engn Edmonton AB T6G 1H9 Canada Guangzhou Med Univ Affiliated Hosp 5 Guangzhou 510700 Guangdong Peoples R China

Coacervation plays a critical role in numerous biological activities such as constructing biological tissues and achieving robust wet adhesion of marine sessile organisms, which conventionally occurs when oppositely charged polyelectrolytes are mixed in aqueous solutions driven by electrostatic attraction. Here, a novel type of adhesive coacervate is reported, driven by hydrogen-bonding interactions, readily formed by mixing silicotungstic acid and nonionic polyethylene glycol in water, providing a new approach for developing coacervates from nonionic systems. The as-prepared coacervate is easily paintable underwater, show strong wet adhesion to diverse substrates, and has been successfully applied as a hemostatic agent to treat organ injuries without displaying hemolytic activity, while with inherent antimicrobial properties thus avoiding inflammations and infections due to microorganism accumulation. This work demonstrates that coacervation can occur in salt-free environments via non-electrostatic interactions, providing a new platform for engineering multifunctional coacervate materials as tissue glues, wound dressings and membrane-free cell systems.

关键词： adhesive coacervates antimicrobial properties coacervation hydrogen bonding wet adhesion

来源：评论

学校读者我要写书评

暂无评论

Highly Robust,Compressible,Anisotropic,and Fire-Retardant Polyimide/Hydroxyapatite Nanowires/Reduced Graphene Oxide Aerogel for Rapid Adsorption of Viscous Oil Assisted by Sunlight

引用

Research 2024年第4期7卷 58-70页

作者： Pan Huang Yongxiang Sun Lin Yang Haoyu Yang Ying Hu Jifang Liu xuwen peng Hongbo Zeng Department of Chemical and Materials Engineering University of AlbertaEdmontonAlberta T6G 1H9Canada Heavy Machinery Engineering Research Center of Education Ministry Taiyuan University of Science and TechnologyTaiyuan 030024China Cancer Center The Fifth Affiliated HospitalGuangzhou Medical UniversityGuangzhou 510700China Department of Chemical Engineering Tsinghua UniversityBeijing 10084China

Improving the adsorption efficiency of porous adsorbent materials for organic liquids with high viscosity is crucial for addressing oil spill *** this study,a high-performance aerogel adsorbent composed of polyimide(PI),hydroxyapatite nanowires(HAPnws),and reduced graphene oxide(rGO)has been fabricated,which leverages reduced flow tortuosity through anisotropic structures and solar-assisted viscosity reduction via photothermal *** prepared anisotropic PI/HAP/rGO aerogel,with directional channels,shows unique mechanical properties with high stiffness along the axial direction and compressibility along the radial direction.

关键词： nanowires viscosity adsorbent

来源：评论

学校读者我要写书评

暂无评论

Recent advances in designing conductive hydrogels for flexible electronics

引用

InfoMat 2020年第5期2卷 843-865页

作者： Qiongyao peng Jingsi Chen Tao Wang xuwen peng Jifang Liu Xiaogang Wang Jianmei Wang Hongbo Zeng Department of Chemical and Materials Engineering University of AlbertaEdmontonAlbertaCanada The Fifth Affiliated Hospital Guangzhou Medical UniversityGuangzhouGuangdongChina Heavy Machinery Engineering Research Center of Education Ministry Taiyuan University of Science and TechnologyTaiyuanChina

Flexible electronics have emerged as an exciting research area in recent years,serving as ideal interfaces bridging biological systems and conventional electronic *** electronics can not only collect physiological signals for human health monitoring but also enrich our daily life with multifunctional smart materials and *** hydrogels(CHs)have become promising candidates for the fabrication of flexible electronics owing to their biocompatibility,adjustable mechanical flexibility,good conductivity,and multiple stimuli-responsive *** achieve on-demand mechanical properties such as stretchability,compressibility,and elasticity,the rational design of polymer networks via modulating chemical and physical intermolecular interactions is ***,the type of conductive components(eg,electron-conductive materials,ions)and the incorporation method also play an important role in the conductivity of ***-CHs usually possess excellent conductivity,while ion-CHs are generally transparent and can generate ion gradients within the hydrogel *** mini review focuses on the recent advances in the design of CHs,introducing various design strategies for electron-CHs and ion-CHs employed in flexible electronics and highlighting their versatile applications such as biosensors,batteries,supercapacitors,nanogenerators,actuators,touch panels,and displays.

关键词： biosensor composite hydrogel conductive hydrogel flexible electronics supercapacitor

来源：评论

学校读者我要写书评

暂无评论

Probing the Interfacial Forces and Surface Interaction Mechanisms in Petroleum Production Processes

引用

Engineering 2022年第11期18卷 49-61页

作者： Diling Yang xuwen peng Qiongyao peng Tao Wang Chenyu Qiao Ziqian Zhao Lu Gong Yueliang Liu Hao Zhang Hongbo Zeng Department of Chemical and Materials Engineering University of AlbertaEdmontonAB T6G 1H9Canada College of Petroleum Engineering China University of PetroleumBeijing 102249China

Despite the advances that have been made in renewable energy over the past decade,crude oil or petroleum remains one of the most important energy resources to the *** production presents many challenging issues,such as the destabilization of complex oil-water emulsions,fouling phenomena on pipelines and other facilities,and water *** problems are influenced by the molecular forces at the oil/water/solid/gas interfaces involved in relevant ***,we present an overview of recent advances on probing the interfacial forces in several petroleum production processes(e.g.,bitumen extraction,emulsion stabilization and destabilization,fouling and antifouling phenomena,and water treatment)by applying nanomechanical measurement technologies such as a surface forces apparatus(SFA)and an atomic force microscope(AFM).The interaction forces between bitumen and mineral solids or air bubbles in the surrounding fluid media determine the bitumen liberation and flotation efficiency in oil sands *** stability of complex oil/water emulsions is governed by the forces between emulsion drops and particularly between interface-active species(e.g.,asphaltenes).Various oil components(e.g.,asphaltenes)and emulsion drops interact with different substrate surfaces(e.g.,pipelines or membranes),influencing fouling phenomena,oil-water separation,and wastewater *** these intermolecular and interfacial forces has advanced the mechanistic understanding of these interfacial interactions,facilitating the development of advanced materials and technologies to solve relevant challenging issues and improve petroleum production *** challenges and suggestions on future research directions in the field are also presented.

关键词： Intermolecular and surface forces Interface Emulsion Colloids Fouling and antifouling Water treatment

来源：评论

学校读者我要写书评

暂无评论

Protective immunity with an E1 multivalent epitope DNA vaccine against cottontail rabbit papillomavirus (CRPV) infection in an HLA-A2.1 transgenic rabbit model

引用

VACCINE 2008年第6期26卷 809-816页

作者： Hu, Jiafen Cladel, Nancy peng, xuwen Balogh, Karla Christensen, Neil D. Penn State Univ Coll Med Dept Immunol & Microbiol Hershey PA 17033 USA Penn State Univ Coll Med Jake Gittien Canc Res Fdn Hershey PA 17033 USA Penn State Univ Coll Med Dept Pathol Hershey PA 17033 USA Penn State Univ Coll Med Dept Comparat Med Hershey PA 17033 USA

Cottontail rabbit papillomavirus (CRPV)/rabbit model is widely used to study pathogenesis of papillomavirus infections and malignant tumor progression. Recently, we established HLA-A2.1 transgenic rabbit lines and demonstrated efficacy for the testing of immunogenicity of a well-known A2-resticted epitope (HPV16E7/82-90) [Hu J, peng X, Schell TD, Budgeon LR, Cladel NM, Christensen ND. An HLA-A2.1-transgenic rabbit model to study immunity to papillomavirus infection. J Immunol 2006;177(11):8037-45]. In the present study, we screened five HLA-A2.1 restricted epitopes from CRPVE1 (selected using online MHCI epitope prediction software) and constructed a multivalent epitope DNA vaccine (CRPVE1ep1-5). CRPVE1ep1-5 and a control DNA vaccine (Ub3) were then delivered intracutaneously onto normal and HLA-A2.1 transgenic rabbits, respectively, by a helium-driven gene-gun delivery system. One, two or three immunizations were given to different groups of animals from both New Zealand White outbred and EIII/JC inbred genetic background. Two and three immunizations with CRPVE1ep1-5 DNA vaccine provided complete protection against viral DNA infection of HLA-A2.1 transgenic rabbits from both genetic backgrounds but not in the control-vaccinated groups. One immunization, however, failed to protect HLA-A2.1 transgenic rabbits against viral DNA infection. This study further demonstrated that the HLA-A2.1 transgenic rabbits can be used to test the immunogenicity of HLA-A2.1 restricted epitopes identified by MHCI epitope predication software. (c) 2007 Elsevier Ltd. All rights reserved.

关键词： CRPVE1 epitope DNA vaccine HLA-A2.1 transgenic rabbit vaccination protective immunity

来源：评论

学校读者我要写书评

暂无评论

Stretchable, compressible, and conductive hydrogel for sensitive wearable soft sensors

引用

JOURNAL OF COLLOID AND INTERFACE SCIENCE 2022年 618卷 111-120页

作者： peng, xuwen Wang, Wenda Yang, Wenshuai Chen, Jingsi peng, Qiongyao Wang, Tao Yang, Diling Wang, Jianmei Zhang, Hao Zeng, Hongbo Univ Alberta Dept Chem & Mat Engn Edmonton AB T6G 1H9 Canada Taiyuan Univ Sci & Technol Heavy Machinery Engn Res Ctr Educ Minist Taiyuan 030024 Peoples R China

Conductive hydrogels hold great promises in wearable soft electronics. However, the weak mechanical properties, low sensitivity and the absence of multifunctionalities (e.g., self-healing, self-adhesive, etc.) of the conventional conductive hydrogels limit their applications. Thus, developing multifunctional hydrogels may address some of these technical issues. In this work, a multifunctional conductive hydro gel strain sensor is fabricated by incorporating a conductive polymer Poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (PEDOT: PSS) into a mechanically robust poly (vinyl alcohol) (PVA)/ poly (acrylic acid) (PAA) double network (DN) hydrogel. The as-prepared hydrogel sensor could span a wide spectrum of mechanical properties by simply tuning the polymer composition and the number of freezing-thawing cycles. In addition, the dynamic hydrogen bonding interactions endow the hydrogel sensor with self healing property and reversible adhesiveness on diverse substrates. Moreover, the hydrogel sensor shows high sensitivity (Gauge Factor from 2.21 to 3.82) and can precisely detect some subtle human motions (e.g., pulse and vocal cord vibration). This work provides useful insights into the development of conductive hydrogel-based wearable soft electronics.(c) 2022 Elsevier Inc. All rights reserved.

关键词： Conductive hydrogel Interfacial interaction Self-healing Soft hydrogel sensors

来源：评论

学校读者我要写书评

暂无评论

Probing Hydrophobic Interactions between Polymer Surfaces and Air Bubbles or Oil Droplets: Effects of Molecular Weight and Surfactants

引用

LANGMUIR 2022年第17期38卷 5257-5268页

作者： Yang, Diling Xie, Lei Mao, Xiaohui Gong, Lu peng, xuwen peng, Qiongyao Wang, Tao Liu, Qi Zeng, Hongbo Zhang, Hao Univ Alberta Dept Chem & Mat Engn Edmonton AB T6G 1H9 Canada

Hydrophobic interaction plays an important role innumerous interfacial phenomena and biophysical and industrial processes. In this work, polystyrene (PS) was used as a modelhydrophobic polymer for investigating its hydrophobic interactionwith highly deformable objects (i.e., air bubbles and oil droplets) inaqueous solutions. The effects of polymer molecular weight,solvent (i.e., addition of ethanol to water), the presence of surface-active species, and hydrodynamic conditions were investigated, viadirect surface force measurements using the bubble/drop probeatomic force microscopy (AFM) technique and theoreticalcalculations based on the Reynolds lubrication theory andaugmented Young-Laplace equation by including the effect ofdisjoining pressure. It was found that the PS of low molecularweight (i.e., PS590 and PS810) showed slightly weaker hydrophobic interactions with air bubbles or oil droplets, as compared toglassy PS of higher molecular weight (i.e., PS1110, PS2330, PS46300, and PS1M). The hydrophobic interaction between PS and airbubbles in a 1 M NaCl aqueous solution with 10 vol % ethanol was weaker than that in the bare aqueous solution. Such effects onthe hydrophobic interactions are possibly achieved by influencing the structuring/ordering of water molecules close to thehydrophobic polymer surfaces by tuning the surface chain mobility and surface roughness of polymers. It was found that the additionof three surface-active species, i.e., cetyltrimethylammonium chloride (CTAC), Pluronic F-127, and sodium dodecyl sulfate (SDS),to the aqueous media could suppress the attachment of the hydrophobic polymer and air bubbles or oil droplets, most likely causedby the additional steric repulsion due to the adsorbed surface-active species at the bubble/polymer/oil interfaces. Our results haveimproved the fundamental understanding of the interaction mechanisms between hydrophobic polymers and gas bubbles or oildroplets, with useful implications on developing effective me

关键词： Atmospheric chemistry Bubbles Liquids Molecular mechanics Solution chemistry

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：