检索结果-南通市图书馆

Journal of Wuhan University of Technology(Materials Science) 2017年第1期32卷 29-32页

作者：韦长成王华 XU Jiwen ZHANG Yupei ZHANG Xiaowen YANG Ling School of Materials Science and Engineering Guilin University of Electrnic TechnologyGuilin 541004China

The Ag/Mg0.2Zn0.8O/ZnMn2O4/p^＋-Si heterostructure devices were fabricated by sol-gel spin coating technique and the resistive switching behavior,conduction mechanism,endurance characteristic,and retention properties were investigated.A distinct bipolar resistive switching behavior of the devices was observed at room temperature.The resistance ratio R_（HRS）/RLRS of high resistance state and low resistance state is as large as four orders of magnitude with a readout voltage of 2.0 V.The dominant conduction mechanism of the device is trap-controlled space charge limited current（SCLC）.The devices exhibit good durability under 1×10^3cycles and the degradation is invisible for more than 10^6 s.

关键词： heterostructure Ag/Mg0.2Zn0.8O/ZnMn2O4/p^＋-Si devices resistive switching properties

Application of Diffusion Brazing in Stockage of Vacuum Electronic devices

在线全文

学校读者我要写书评

暂无评论

稀有金属材料与工程 2011年第S3期40卷 19-22页

作者： Li Haitao, Qu Wenqing, Zhuang Hongshou Beijing University of Aeron. & Astro., Beijing 300072, China Beijing Univ Aeron & Astro Beijing 300072 Peoples R China

The vacuum electronic device is the key components widely used in the fields of radar, navigation, electronic warfare and so on. Multi-brazing process is adopted in the manufacturing, and the leakage is easy to happen at many parts, such as brazed seams and base materials of tube shell, leading breakage of the devices. But now the brazing filler metal used in the stockage of vacuum electronic devices is very seldom. For the safe of vacuum electronic devices, stockage temperature must be lower than the brazing temperature. Gallium is liquid at room temperature, and has a lower vapor pressure. The Ga-based alloy can diffuse with the high melting point metal, and then form heat-resistance and a good sealing performance of solid-state alloys. In this study three kinds of Ga-based alloys used for the stockage were developed. The diffusion brazing for the stockage on three materials with defect, such as OFHC, kovar and Ag-Cu brazed seams was carried out. The influence factors such as parent materials, brazing filler metal and brazing temperature on the stockage quality were discussed. The results indicated that parent materials, brazing filler metals and brazing temperature had obvious influences on stockage. For OFHC and Ag-Cu filler with defects, the stockage effects were better than kovar. The effect of Ga-In-Cu alloy was the best because the compact diffusion layer was formed between the stockage brazing materials and base materials. As the brazing temperature went up, the diffusion layer formed between stockage material and OFHC, kovar became obviously thicker, the stockage effect got better. For Ag-Cu brazing seams, the stockage effect was satisfactory at 500 ℃, erosion will happen at the higher temperature.

关键词： vacuum electronic devices vacuum brazing stockage diffusion brazing

Highly efficient stacked organic light-emitting devices employing a novel intermediate layer

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2009年第1期52卷 95-98页

作者： NIU LianBin GUAN YunXia REN Yue KONG ChunYang MA Yan LIANG YiPing Key Laboratory of Optical Engineering College of Physics and Information TechnologyChongqing Normal UniversityChongqing 400047China

Highly efficient stacked organic light-emitting devices (OLEDs) have been fabricated using Mg:Alq3:BCP/ WO3 as a novel intermediate layer, which connects two identical emissive units. The stacked OLEDs consisting of NPB/Alq3 exhibited high current efficiency and brightness characteristics over conven- tional single-unit device. At 200 mA/cm2, the current efficiency of the stacked OLEDs using the inter- mediate layers of Mg:Alq3:BCP/WO3 were about 6.85 cd/A, doubling that of the conventional device. The results may prove the method to be effective to enhance the current efficiency and brightness of OLEDs.

关键词： organic light-emitting devices Mg:Alq3:BCP/WO3 stacked

Multistage interband cascade photovoltaic devices with a bandgap of 0.23 eV operating above room temperature

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2014年第10期59卷 950-955页

作者： Hao Ye Hossein Lotfi Lu Li Robert T.Hinkey Rui Q.Yang Lin Lei Joel C.Keay Matthew B.Johnson Tetsuya D.Mishima Michael B.Santos School of Electrical and Computer Engineering University of Oklahoma Norman OK USA Homer L. Dodge Department of Physics and Astronomy University of Oklahoma Norman OK USA

Interband cascade(IC)photovoltaic(PV)device structures,consisting of multiple discrete InAs/GaSb superlattice absorbers sandwiched between electron and hole barriers,were grown by molecular beam epitaxy.Details of the molecular beam epitaxy growth and material characterization of the structures are presented.The discrete absorber architecture enables certain advantages,such as high open-circuit voltage,high collection efficiency,high operating temperature,and smooth integration of cascade stages with different bandgaps.The two-and three-stage ICPV devices presented in this article operate at room temperature with substantial open-circuit voltages at a cutoff wavelength of 5.3 lm(corresponding to a bandgap of 0.23 eV),the longest ever reported for room temperature PV devices.The device characteristics indicate a high level of current matching and demonstrate the advantages of the interband cascade approach in thermophotovoltaic cell design.

关键词： InAs GaSb superlattice Thermophotovoltaic Interband cascade devices

Development of Energy-Saving devices for a 20,000DWT River–Sea Bulk Carrier

在线全文

学校读者我要写书评

暂无评论

Journal of Marine Science and Application 2018年第1期17卷 131-139页

作者： Kunpeng Chen Yuling Gao Zhenping Huang Guoxiang Dong State Key Laboratory of Navigation and Safety Technology Shanghai Ship&Shipping Research InstituteShanghai 200135China

A reduction of fuel consumption and an increase in efficiency are currently required for river–sea bulk carriers.Pre-swirl and ducted stators are widely used devices in the industry and efficiency gains can be obtained for single-screw and twin-screw vessels.Based on the hydrodynamic characteristics of the 20,000DWT river–sea bulk carrier,in this study,we proposed,designed,and tested a series of pre-swirl energy-saving devices(ESDs).The experimental results demonstrate that the proposed ESDs improved the propulsive efficiency and reduced the delivered power.The results confirm the success of our ESD for the 20,000DWT river–sea bulk carrier.We validated the role of Reynolds-averaged Navier–Stokes(RANS)computational fluid dynamics(CFD)in the twin-skeg river–sea vessel ESD design and found the circumferential arrangement and number of stators to be important factors in the design process.

关键词： River–sea bulk carrier Energy-saving devices Pre-swirl stators Computational fluid dynamics RANS

Editorial for special issue on lithium niobate based photonic devices

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2021年第6期19卷 1-2页

作者： Feng Chen 1,* Yuping Chen 2 Shandong University China Shanghai Jiao Tong University China

Lithium niobate(LiNbO 3),so-called“Silicon in Photonics,”is a multifunctional crystal with a combination of a number of excellent physicalproperties.Inopticsandphotonics,theLiNbO 3-baseddevices,suchasmodulators,wavelengthconverters,waveguideampli-fiers,and quantum photonic chips,have been realized and widely applied in various areas.

关键词： properties. waveguide devices

Management strategies for allergic reaction following implantation of nickel-containing devices

在线全文

学校读者我要写书评

暂无评论

Journal of Interventional Medicine 2019年第3期2卷 139-140页

作者： Zhongzhi Jia Department of Interventional Radiology The Affiliated Changzhou No.2 People’s Hospital of Nanjing Medical UniversityChangzhou213003China

Over the last thirty years,nickel-containing devices have been widely implemented.These include inferior vena cava(IVC)filters,amplatzer occluders,vascular and non-vascular stents,and other endovascular and implantable devices.Hypersensitivity to these nickel-containing devices has been well documented in the literature and has been reported to cause a major burden to the patients who have received nickelcontaining device implants.Therefore,efforts for prevention,diagnosis,and management of hypersensitivity to nickel-containing devices are strongly encouraged.

关键词： Management strategies nickel-containing devices inferior vena cava

A SPARSE MATRIX TECHNIQUE FOR SIMULATING SEMICONDUCTOR devices AND ITS ALGORITHMS

在线全文

学校读者我要写书评

暂无评论

Journal of Electronics(China) 1990年第1期7卷 77-82页

作者：任建民张义门 Xidian University Xian

A novel sparse matrix technique for the numerical analysis of semiconductor devicesand its algorithms are presented.Storage scheme and calculation procedure of the sparse matrixare described in detail.The sparse matrix technique in the device simulation can decrease storagegreatly with less CPU time and its implementation is very easy.Some algorithms and calculationexamples to show the time and space characteristics of the sparse matrix are given.

关键词： Semiconductor devices Sparse matrix technique Algorithm CAD

Ionic Liquid Engineering in Perovskite Photovoltaics

在线全文

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2023年第5期6卷 1-21页

作者： Fei Wang Dawei Duan Mriganka Singh Carolin M.Sutter-Fella Haoran Lin Liang Li Panče Naumov Hanlin Hu Hoffman Institute of Advanced Materials Shenzhen PolytechnicShenzhen 518000China Molecular Foundry Division Lawrence Berkeley National LaboratoryBerkeley California 94720USA Department of Sciences and Engineering Sorbonne University Abu Dhabi38044Abu DhabiUnited Arab Emirates Smart Materials Lab New York University Abu Dhabi129188Abu DhabiUnited Arab Emirates Molecular Design Institute Department of ChemistryNew York University100 Washington Square EastNew YorkNY 10003USA

Over the past decade,perovskite photovoltaics have approached other currently available technologies and proven to be the most prospective type of solar cells.Although the many-sided research in this very active field has generated consistent results with regard to their undisputed consistently increasing power conversion efficiency,it also produced several rather contradictory opinions.Among other important details,debate surrounding their proneness to surface degradation and poor mechanical robustness,as well as the environmental footprint of this materials class,remains a moot point.The application of ionic liquids appears as one of the potential remedies to some of these challenges due to their high conductivity,the opportunities for chemical"tuning"of the structure,and relatively lower environmental footprint.This article provides an overview,classification,and applications of ionic liquids in perovskite solar cells.We summarize the use and role of ionic liquids as versatile additives,solvents,and modifiers in perovskite precursor solution,in charge transport layer,and in interfacial and stability engineering.Finally,challenges and the future prospects for the design and/or selection of ionic liquids with a specific profile that meets the requirements for next-generation highly efficient and stable perovskite solar cells are proposed.

关键词： devices ionic liquids perovskites photovoltaics

Optimized cardiac magnetic resonance imaging inversion recovery sequence for metal artifact reduction and accurate myocardial scar assessment in patients with cardiac implantable electronic devices

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Radiology 2018年第9期10卷 100-107页

作者： El-Sayed H Ibrahim Mason Runge Jadranka Stojanovska Prachi Agarwal Maryam Ghadimi-Mahani Anil Attili Thomas Chenevert Chiel den Harder Frank Bogun Department of Radiology Medical College of Wisconsin Department of Radiology University of Michigan Department of Medical Physics Leiden University Medical Center

Late gadolinium enhancement(LGE) cardiovascular magnetic resonance(CMR) is the gold standard for imaging myocardial viability.An important application of LGE CMR is the assessment of the location and extent of the myocardial scar in patients with ventricular tachycardia(VT), which allows for more accurate identification of the ablation targets.However, a large percentage of patients with VT have cardiac implantable electronic devices(CIEDs), which is a relative contraindication for cardiac magnetic resonance imaging due to safety and image artifact concerns.Previous studies showed that these patients can be safely scanned on 1.5 T scanners provided that an adequate imaging protocol is adopted.Nevertheless, imaging patients with a CIED result in metal artifacts due to the strong frequency off-resonance effects near the device; therefore, the spins in the surrounding myocardium are not completely inverted, and thus give rise to hyperintensity artifacts.These artifacts obscure the myocardial scar tissue and limit the ability to study the correlation between the myocardial scar structure and the electro-anatomical map during catheter ablation.In this study, we developed a modified inversion recovery technique to alleviate the CIED-induced metal artifacts and improve the diagnostic image quality of LGE images in patients with CIEDs without increasing scan time or requiring additional hardware.The developed technique was tested in phantom experiments and in vivo scans, which showed its capability for suppressing the hyperintensity artifacts without compromising myocardium nulling in the resulting LGE images.

关键词： Magnetic resonance imaging Heart Late gadolinium enhancement Viability imaging Inversion recovery Cardiac implantable electronic devices