检索结果-内蒙古大学图书馆

Mapping gradient-driven morphological phase transition at the conductive domain walls of strained multiferroic films

引用

Physical Review B 2019年第10期100卷 104109-104109页

作者： M. J. Han E. A. Eliseev A. N. Morozovska Y. L. Zhu Y. L. Tang Y. J. Wang X. W. Guo X. L. Ma Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Wenhua Road 72 110016 Shenyang China University of Chinese Academy of Sciences Yuquan Road 19 100049 Beijing China Institute for Problems of Materials Science National Academy of Sciences of Ukraine Krjijanovskogo 3 03142 Kyiv Ukraine Institute of Physics National Academy of Sciences of Ukraine 46 Prospekt Nauky 03028 Kyiv Ukraine University of Science and Technology of China Jinzhai Road 96 230026 Hefei China State Key Lab of Advanced Processing and Recycling on Non-ferrous Metals Lanzhou University of Technology Langongping Road 287 730050 Lanzhou China

The coupling between antiferrodistortion (AFD) and ferroelectric (FE) polarization, universal for all tilted perovskite multiferroics, is known to strongly correlate with domain wall functionalities in the materials. The intrinsic mechanisms of domain wall phenomena, especially AFD-FE coupling-induced phenomena at the domain walls, have continued to intrigue the scientific and technological communities because of the need to develop future nanoscale electronic devices. Over the past years, theoretical studies have often shown controversial results, owing to the fact that they are neither sufficiently nor directly corroborated with experimental evidence. In this work, the AFD-FE coupling at uncharged 180° and 71° domain walls in BiFeO3 films is investigated by means of aberration-corrected scanning transmission electron microscopy with high-resolution scanning transmission electron microscopy and rationalized by phenomenological Landau-Ginzburg-Devonshire (LGD) theory. We reveal a peculiar morphology at the AFD-FE walls, including kinks, meandering, and trianglelike regions with opposite oxygen displacements and curvature near the interface. The LGD theory confirms that the tilt gradient energy induces these unusual morphologies and the features would change delicately with different kinds of domain walls. Moreover, the 180° AFD-FE walls are proved to be conductive with an unexpected reduction of the Fe-O-Fe bond angle, which is distinct from theoretical predictions. By exploring AFD-FE coupling at the domain walls, and its induced functionalities, we provide exciting evidence into the links between structural distortions and its electronic properties, which provide great benefit for fundamental understanding of domain wall functionalities as well as functional manipulations for novel nanodevices.

关键词： Domain walls Ferroelectricity Atomic force microscopy Transmission electron microscopy

来源：评论

学校读者我要写书评

暂无评论

Silk Fibroin Scaffolds Direct Neural and Glial Differentiation from Embryonic Stem Cells

引用

医用生物力学 2019年第A01期34卷 163-163页

作者： Yawen Liao Peng Tang Yao Zhang Zhanao Hu Yongning Zhang Shangbang Gao Qiang Zhang Ning Wang Laboratory for Cellular Biomechanics and Regenerative Medicine Department of Biomedical EngineeringCollege of Life Science and TechnologyHuazhong University of Science and TechnologyWuhan430074China State Key Laboratoryfor Hubei New Textile Materials and Advanced Processing Technology School of Textile Science and EngineeringWuhan Textile UniversityWuhan430074China Key Laboratory of Molecular Biophysics of the Ministry of Education International Research Center for Sensory Biology and Technology of the Ministry of Science and TechnologyHuazhongUniversity of Science and TechnologyWuhan430074China Department of Mechanical Science and Engineering College of EngineeringUniversity of Illinois at Urbana-ChampaignUrbanaIL61801USA

Spinal cord injury repair is one of the major challenges in medicine,as it can lead to permanent loss of function of central nervous system and damage to other function of the *** cell transplantation together with tissue engineering is increasingly becoming a potential choice of ***,direct transplantation of stem cells without scaffolds has yielded poor clinical *** we show a strategy of using mouse embryonic stem cells(ESCs)cultured within a silk fibroin(SF)based,three-dimensional scaffold with oriented channels by a directional temperature field freezing technique and *** find that the ESCs maintained proliferation and migrated in the scaffolds and the cells migrated fastest along the SF *** scaffolds contributed to ESC differentiation into neural and glial cell like cells and expressions of the neural and glial cell markers MAP2 and GFAP were greatly elevated when retinoic acid was used as an inducing *** results suggest that this approach may offer some hope in the future for spinal cord injury repair using SF scaffolds and ESCs.

关键词： Silk Fibroin Scaffolds Direct Neural Glial Differentiation Embryonic Stem Cells

来源：评论

学校读者我要写书评

暂无评论

Role of the lattice in the light-induced insulator-to-metal transition in vanadium dioxide

引用

Physical Review Research 2020年第2期2卷 023076-023076页

作者： Cédric Weber Swagata Acharya Brian Cunningham Myrta Grüning Liangliang Zhang Hang Zhao Yong Tan Yan Zhang Cunlin Zhang Kai Liu Mark Van Schilfgaarde Mostafa Shalaby King's College London The Strand WC2R 2LS London United Kingdom School of Mathematics and Physics Queen's University Belfast Belfast BT7 1NN United Kingdom Key Laboratory of Terahertz Optoelectronics Beijing Advanced Innovation Center for Imaging Technology CNU Beijing 100048 China Beijing Key Laboratory for Precision Optoelectronic Measurement Instrument and Technology School of Optics and Photonics Beijing Institute of Technology Beijing 100081 China State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and Engineering Tsinghua University Beijing 100084 China National Renewable Energy Laboratories Golden Colorado 80401 USA Swiss Terahertz Research-Zurich Technopark 8005 Zurich Switzerland and Park Innovaare 5234 Villigen Switzerland

Vanadium dioxide is a model material system which exhibits a metal-to-insulator transition at 67∘C. This holds potential for future ultrafast switching in memory devices but typically requires a purely electronic process to avoid the slow lattice response. The role of lattice vibrations is thus important, but it is not fully understood and it has been a long-standing source of controversy. We use ultrafast spectroscopy and ab initio quantum calculations to study the mechanism responsible for the transition. We identify an atypical Peierls vibrational mode associated with the transition and study its associated properties. Our findings led to theoretical prediction of a new electron-phonon pathway for a purely reversible electronic transition in a true bistable fashion under specific conditions. This transition is very atypical, as it involves purely chargelike excitations and requires only small nuclear displacement and might prompt future experimental investigations.

关键词： Electrical properties Electronic structure First-principles calculations Metal-insulator transition Peierls transition Vanadates Ultrafast pump-probe spectroscopy

来源：评论

学校读者我要写书评

暂无评论

Effects of crystallinity and surface modification of calcium phosphate nanoparticles on the loading and release of tetracycline hydro-chloride

引用

IOP Conference Series: materials Science and Engineering 2017年第1期182卷

作者： Huaizhi Zhang Dong Yan Sriyani Menike Korale Gedara Sajith Sudeepa Fernando Dingiri Marakkalage Jothirathna Gamage Kasun Methlal YingChao Han HongLian Dai State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China Biomedical Materials and Engineering Research Center of Hubei Province Wuhan University of Technology Wuhan 430070 China Faculty of Applied Sciences Sabaragamuwa University of Sri Lanka Belihuloya 70140 Sri Lanka

The influences of crystallinity and surface modification of calcium phosphate nanoparticles (nCaP) on their drug loading capacity and drug release profile were studied in the present investigation. The CaP nanoparticles with different crystallinity were prepared by precipitation method under different temperatures. CaP nanoparticles with lower crystallinity exhibited higher drug loading capacity. The samples were characterized by XRD, FT-IR, SEM, TEM and BET surface area analyzer respectively. The drug loading capacity of nCaP was evaluated to tetracycline hydro-chloride (TCH). The internalization of TCH loaded nCaP in cancer cell was observed by florescence microscope. nCaP could be stabilized and dispersed in aqueous solution by poly(acrylic acid) surface modification agent, leading to enhanced drug loading capacity. The drug release was conducted in different pH environment and the experimental data proved that nCaP were pH sensitive drug carrier, suggesting that nCaP could achieve the controlled drug release in intracellular acidic environment. Furthermore, nCaP with higher crystallinity showed lower drug release rate than that of lower crystallinity, indicating that the drug release profile could be adjusted by crystallinity of nCaP. nCaP with adjustable drug loading and release properties are promising candidate as drug carrier for disease treatment.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Design of D0 22 Superlattice with Superior Strengthening Effect in High Entropy Alloys

SSRN

引用

SSRN 2018年

作者： He, Feng Chen, Da Han, Bin Wu, Qingfeng Wang, Zhijun Wei, Shaolou Wei, Daixiu Wang, Jincheng Liu, C.T. Kai, Ji-Jung State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi'an710072 China Department of Mechanical and Biomedical Engineering City University of Hong Kong Hong Kong Department of Materials Science and Engineering Massachusetts Institute of Technology CambridgeMA02139 United States Institute for Materials Research Tohoku University 2-1-1 Katahira Sendai Miyagi 980-8577 Japan Centre for Advanced Nuclear Safety and Sustainable Development City University of Hong Kong Hong Kong

Precipitation strengthening is one of the most promising mechanisms to develop high-performance high entropy alloys (HEAs). However, the design of a reinforcing phase with an excellent strengthening effect is still one of the most pivotal challenges. In the present study, a design strategy based on overall valence electron concentration (OVEC) is developed, and a coherent γ″ phase with superior strengthening effect is designed. The newly developed γ″ phase is systematically characterized using transmission electron microscope and atom probe tomography. Differentiating from the traditional Ni3Nb γ″ phase, the present high-entropy γ″ phase contains ~7.7% Co and follows the (Ni,Co,Cr,Fe)3(Nb,Fe) stoichiometry. Three γ″ phase variants are observed with crystallographic orientation relationships of [001]γ″//γ and (001)γ″//{100}γ. The lenticular γ″ particles with small volume fraction (7%) causes a significant yield strength increase (670 MPa) and ductility retention (40%), resulting in excellent yield strength-ductility combination. The excellent strengthening effect of the γ″ phase is attributed to both ordering strengthening and coherency strengthening. The present study proposes a new design strategy of precipitates and develops a superior reinforcing phase for HEAs. These findings not only promote the development of precipitation-strengthened HEAs but deepen the understanding of precipitates design in HEAs as well. © 2018, The Authors. All rights reserved.

关键词： Entropy

来源：评论

学校读者我要写书评

暂无评论

Commercial indium-tin oxide glass:A catalyst electrode for efficient N_(2)reduction at ambient conditions

引用

Chinese Journal of Catalysis 2021年第6期42卷 1024-1029页

作者： Ting Wang Shaoxiong Li Bingling He Xiaojuan Zhu Yonglan Luo Qian Liu Tingshuai Li Siyu Lu Chen Ye Abdullah M.Asiri Xuping Sun Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province College of Chemistry and Chemical EngineeringChina West Normal UniversityNanchong 637002SichuanChina College of Physics and Electronic Engineering Xinxiang UniversityXinxiang 453003HenanChina Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054SichuanChina Green Catalysis Center and College of ChemistryZhengzhou UniversityZhengzhou 450001HenanChina College of Chemistry Sichuan UniversityChengdu 610064SichuanChina Chemistry Department Faculty of Science&Center of Excellence for Advanced Materials ResearchKing Abdulaziz UniversityP.O.Box 80203Jeddah 21589Saudi Arabia

The typical Haber technical process for industrial NH_(3)production involves plenty of energy-consumption and large quantities of greenhouse gas *** contrast,electrochemical N_(2)reduction proffers environment-friendly and energy-efficient avenues to synthesize NH_(3)at mild conditions but demands efficient electrocatalysts for the N_(2)reduction reaction(NRR).Herein we report for the first time that commercial indium-tin oxide glass(ITO/G)can be used as a catalyst electrode toward artificial N_(2)fixation,as it demonstrates excellent selectivity at mild *** ITO/G delivers excellent NRR performance with a NH_(3)yield of 1.06×10^(-10) mol s^(-1) cm^(-2) and a faradaic efficiency of 6.17%at-0.40 V versus the reversible hydrogen electrode(RHE)in 0.5 M ***,the ITO/G also possesses good electrochemical stability and ***,the possible reaction mechanism for the NRR on the ITO catalysts was explored using first-principles calculations.

关键词： N_(2)reduction reaction NH_(3) Indium-tin oxide Electrocatalyst Ambient conditions Density functional theory

来源：评论

学校读者我要写书评

暂无评论

Highly efficient acousto-optic modulation using nonsuspended thin-film lithium niobate-chalcogenide hybrid waveguides

arXiv

引用

arXiv 2021年

作者： Wan, Lei Yang, Zhiqiang Zhou, Wenfeng Wen, Meixun Feng, Tianhua Zeng, Siqing Liu, Dong Li, Huan Pan, Jingshun Zhu, Ning Liu, Weiping Li, Zhaohui Department of Electronic Engineering College of Information Science and Technology Jinan University Guangzhou510632 China Guangdong Provincial Key Laboratory of Optoelectronic Information Processing Chips and Systems Sun Yat-sen University Guangzhou510275 China State Key Laboratory for Modern Optical Instrumentation College of Optical Science and Engineering International Research Center for Advanced Photonics Zhejiang University Zijingang Campus Hangzhou310058 China Institute of Semiconductor Science and Technology Guangdong Engineering Technology Research Center of Low Carbon and New Energy Materials South China Normal University Guangzhou510631 China Zhuhai519000 China

A highly efficient on-chip acousto-optic modulator, as a key component, occupies an exceptional position in microwave-to-optical conversion. Homogeneous thin-film lithium niobate is preferentially employed to build the suspended configuration forming the acoustic resonant cavity to improve the modulation efficiency of the device. However, the limited cavity length and complex fabrication recipe of the suspended prototype restrain further breakthrough in the ME and impose challenges for waveguide fabrication. In this work, based on a nonsuspended thin-film lithium niobate-chalcogenide glass hybrid Mach–Zehnder interferometer waveguide platform, we propose and demonstrate a built-in push-pull acousto-optic modulator with a half-wave-voltage-length product VπL as low as 0.03 V cm, presenting a modulation efficiency comparable to that of the state-of-the-art suspended counterpart. Based on the advantage of low power consumption, a microwave modulation link is demonstrated using our developed built-in push-pull acousto-optic modulator. The nontrivial acousto-optic modulation performance benefits from the superior photoelastic property of the chalcogenide membrane and the completely bidirectional participation of the antisymmetric Rayleigh surface acoustic wave mode excited by the impedance-matched interdigital transducer, overcoming the issue of amplitude differences of surface acoustic waves applied to the Mach–Zehnder interferometer two arms in traditional push-pull acousto-optic modulators. Copyright © 2021, The Authors. All rights reserved.

关键词： Thin films

来源：评论

学校读者我要写书评

暂无评论

Modeling and simulation of two port proportional slip-in cartridge valve based on AMESim

引用

Journal of Physics: Conference Series 2019年第1期1303卷

作者： Wenzhu Wang Rendong Wu Chaolong Yuan Baohua Chang Dong Du Department of Mechanical Engineering Tsinghua University Beijing 100084 China Key Laboratory for Advanced Materials Processing Technology Ministry of Education Beijing 100084 China

Two port proportional slip-in cartridge valves are critical components of the heavy duty press hydraulic system. Their performance, especially the static flow rate under different valve opening size and the valve response time, is important to the press velocity control precision. So, it is necessary to build an accurate model of the valve to analyse different parameters' influences on the valve performance. Based on the analysis of the valve structure and working principle, the valve model is established by the AMESim. The valve flow rate under different valve opening size ratio is calculated using the simulation model. The rated flow rate calculated by the simulation model is 0.33% less than the sample value, and the variation trend of the calculated flow rate curve is consistent with the manual curve. This demonstrates the considerable effectiveness of the valve simulation model. Then, the influences of the spring stiffness, the pilot oil pressure and the pilot valve gain on the valve poppet response time are analysed using the simulation model, respectively. This research may offer the basis for the whole hydraulic system building and control strategy designing.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Feedforward control of droplet transition in electron beam freeform fabrication based on dual beam spot method

引用

Journal of Physics: Conference Series 2021年第1期1983卷

作者： Haoyu Zhang Zhiyue Liang Shuhe Chang Dong Du Department of Mechanical Engineering Tsinghua University Beijing 100084 China Key Laboratory for Advanced Materials Processing Technology Ministry of Education Beijing 100084 China

In this paper, a feedforward control method of droplet transition based on dual beam spot in electron beam freeform fabrication is proposed. A deflection coil is used to form two beam spots on the surface of the workpiece. Images containing the prepositive spot are taken, the height information of the workpiece surface is obtained through image processing method, and feedforward control is performed accordingly. The experiment result shows that the proposed method has excellent detection accuracy. It can keep the droplet transition distance and state stable when the height of the surface to be deposited fluctuates, and achieve uniform and stable deposition morphology.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Bubble growth in the preparation of mesophase-pitch-based carbon foams

引用

Carbon 2009年第8期47卷 2145-2145页

作者： Mei-Xian Wang Cheng-Yang Wang Ming-Ming Chen Tong-Qi Li Zi-Jun Hu Key Laboratory for Green Chemical Technology of State Education Ministry School of Chemical Engineering and Technology Tianjin University Tianjin 300072 China National Key Laboratory of Advanced Functional Composite Materials Aerospace Research Institute of Materials and Processing Technology Beijing 100076 China

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：