检索结果-南通市图书馆

Synthesis, characterization, and thermostability of bis(2,2,6,6-tetramethyl-3,5-heptanedionato)barium(Ⅱ)

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

Rare Metals 2013年第1期32卷 67-74页

作者： Teng Zhang Hong-Wei Gu fa-zhu ding Fei Qu Shao-Tao Dai Key Laboratory of Applied Superconductivity Institute of Electrical Engineering Chinese Academy of Sciences

The metal-organic chemical vapor deposition （MOCVD） technique is a promising process for high-tem- perature superconductor YBa2Cu307_6（YBCO） preparation. In this technique, it is a challenge to obtain barium precursors with high volatility. In addition, the purity, evaporation characteristics, and thermostability of adopted precursors in whole process will decide the quality and reproducible results of YBCO film. In the present report, bis（2,2,6,6-tetramethyl- 3,5-heptanedionato）barium（II）（Ba（TMHD）2） was synthe- sized, and its structure was identified by PTIR, 1H NMR, 13C NMR, and ESI-MS spectroscopy. Subsequently, the thermal properties and the kinetics of decomposition were systemati- cally investigated by nonisothermal thermogravimetric anal- ysis methods. Based on the average apparent activation energy evaluated by the Ozawa, Kissinger, and Friedman methods, the volatilization process was discussed, and all results show that Ba（TMHD）2 is unstable and highly sensitive to the change of temperature during the whole evaporation process. There- fore, it is very important to choose suitable volatilization technology and conditions for avoiding Ba（TMHD）2 break- down （or thermal aging） during MOCVD process. Subse- quently, the possible conversion function is estimated through the Coats-Redfern method to characterize the evaporation patterns and follows a phase boundary reaction mechanism by the contracting surface equation with average activation energy of 118.7 ***1-1.

关键词： Ba(TMHD)2 Metal-organic chemical vapordeposition (MOCVD) Synthesis Thermostability

Growth mechanism of CdS film prepared by chemical bath deposition

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2014年第3期33卷 324-329页

作者： Xing-Yu Peng Hong-Wei Gu Teng Zhang fa-zhu ding Fei Qu Hong-Yan Wang Key Laboratory of Applied Superconductivity Institute of Electrical Engineering Chinese Academy of Sciences University of Chinese Academy of Sciences

In this paper, sodium citrate was adopted as a complexing agent and ammonia merely served as pH adjustor to investigate the growth mechanism of CdS film The growth rate, structural properties, surface morphology microstructure, and optical properties of CdS films were studied by profilometer, X-ray diffractometer（XRD）scanning electron microscopy（SEM）, transmission elec tron microscopy（TEM）, and spectrophotometer, respec tively. The SEM images show that CdS films prepared with higher ammonia concentration have lower nucleation density on substrate. SEM and EDS results show that the formation of Cd（OH）2is not required in the growth of CdS film. As the ammonia concentration increases, the sites tha previously adsorbed S2-are taken by OH-which leads to lower S2-density on substrate. CdS film forms through direct reaction of Cd2？with the S2-which are adsorbed on the substrate. Lower S2-density on the substrate results in the decrease of particle density on the substrate. The as deposited CdS films have relatively high-average trans mittance（＊80 %） in the wavelength range from 500 to1,000 nm which makes them suitable to be used in sola cell.

关键词： CdS Chemical bath deposition Ammoniaconcentration Growth mechanism

Microstructure and superconducting properties of (BaTiO3,Y2O3)-doped YBCO films under different firing temperatures

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2017年第1期36卷 37-41页

作者： Hong-Yan Wang fa-zhu ding Hong-Wei Gu Hui-Liang Zhang Ze-Bin Dong University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Applied Superconductivity Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190 China

YBaCuO(YBCO) films with co-doping of Ba Ti O(BTO) and YOnanostructures were successfully fabricated on La Al O(LAO) substrate by metal organic deposition using trifluoroacetates(Tfa-MOD). The focus of this study was to optimize the process conditions during the firing heat treatment of high critical current density(J C)-co-doped YBCO films. The effect of the firing temperatures on both the surface morphology and the superconducting properties for the doped YBCO films was systematically studied. According to the X-ray diffraction(XRD) and scanning electron microscopy(SEM) results,the films prepared at 820 and 850 °C show poor electrical performance due to impurity phases and large pores. In contrast, the dense YBCO films prepared at 830 and840 °C with the critical current densities of 10 MA-cm(77 K, 0 T) are obtained.

关键词： YBa2Cu3O7-x BaTiO3 and Y2O3 nanostructures Firing temperature Tfa-MOD

Morphological evolution of CdS films prepared by chemical bath deposition

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2013年第4期32卷 380-389页

作者： Xing-Yu Peng Hong-Wei Gu Teng Zhang Fei Qu fa-zhu ding Hong-Yan Wang Key Laboratory of Applied Superconductivity Institute of Electrical Engineering Chinese Academy of Sciences

In this article, the growth process of chemical bath deposited CdS films was systematically investigated. The structural, optical, and morphological properties were investigated by X-ray diffraction （XRD）, transmission electron microscope （TEM）, UV-Vis spectrophotometer, scanning electron microscope （SEM）, respectively. CdS nanocubes with size of less than 500 nm and nanocrystal-lites with diameter of less than 5 nm forming in reaction solution are observed. According to the TEM results and the SEM morphological evolution of CdS films, a crystal-lite-by-crystallite growth mechanism is proposed to eluci-date the growth process of chemical bath deposited CdS films based on the present growth mechanism.

关键词： CdS Chemical bath deposition Growthmechanism Crystallite-by-crystallite

Electrical and optical properties of ZnO:Al films with different hydrogen contents in sputtering gas

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2015年第3期34卷 173-177页

作者： Fei Qu Teng Zhang Hong-Wei Gu Qing-Quan Qiu fa-zhu ding Xing-Yu Peng Hong-Yan Wang Applied Superconductors Key Laboratory Institute of Electrical EngineeringChinese Academy Sciences

Aluminum-doped zinc oxide （ZnO：AI） films were deposited by direct current magnetron sputtering in incorporating hydrogen in sputtering gas at room temper- ature. The influences of hydrogen content in sputtering gas on the structural, optical, and electrical properties of ZnO：A1 films were systematically investigated. It is found that hydrogen incorporated into ZnO lattice forms shallow donors in ZnO：A1 films and plays an important role in the properties of ZnO：A1 films. The electrical conductivity and infrared （IR） reflectance are improved due to the increase of electron carrier concentration, and the average trans- mittance decreases, which is ascribed to the strong scat- tering from the hydrogen incorporated and oxygen vacancies in ZnO：A1 films. In this study, the resistivity of 5.5 × 10-4 Ω.cm is obtained, the average transmittance of the wavelength in the range of 400-900 nm is almost 86 %, and the IR reflectance reaches 75 % at 2,500 nm, which is higher than that of reported TCO films. The band gap determined by optical absorption is a result of com- petition between Burstein-Moss effect and many-body perturbation effect. However, the hydrogen content in sputtering gas is above 10 %, and the optical band gap shift is independent of hydrogen content in sputtering gas.

关键词： ZnO:A1 thin films Hydrogen Electricalresistivity Transmittance IR reflectance

Substrate angle-induced fully c-axis orientation of AlN films deposited by off-normal DC sputtering method

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2021年第12期40卷 3668-3675页

作者： Bo-Wei Xie fa-zhu ding Hong-Jing Shang Da-Xing Huang Tai-Guang Li Qi Zou Ji-Liang Zhang Hong-Wei Gu Key Laboratory of Applied Superconductivity Chinese Academy of SciencesBeijing 100190China Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Department of Materials Science and Engineering Korea UniversitySeoul 02841Republic of Korea

A highly c-axis-oriented aluminum nitride(Al N)thin film with smooth and crack-free surface was fabricated by an off-normal direct current(DC)sputtering method in a pure nitrogen atmosphere,in which the rotatable substrate holder positioned in the middle of four side targets was a key approach to guarantee the grain growth with no *** detailed effects of substrate angle on the c-axis orientation of Al N films were investigated by varying the substrate angle from 0°to 90°.Moreover,theoretical analysis and Monte Carlo(MC)simulation reveal that the oblique or even vertical angle could improve the lateral kinetic energy of sputtered atoms deposited on the growing film.A variety of examining techniques including X-ray diffraction(XRD),(002)peak rocking curve,scanning electron microscopy(SEM)were conducted to evaluate the angle dependence on the crystallographic *** test results indicate that larger substrate angle is beneficial to the(002)growth of Al N thin film,and a fully c-axis textured Al N thin film is obtained at 90°with small surface roughness(R_(a))of 3.32 nm.

关键词： AlN film c-axis orientation Off-normal DC sputtering Rotating substrate Side target

Emerging Flexible Thermally Conductive Films:Mechanism,fabrication,Application

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2022年第8期14卷 24-57页

作者： Chang‑Ping Feng fang Wei Kai‑Yin Sun Yan Wang Hong‑Bo Lan Hong‑Jing Shang fa‑zhu ding Lu Bai Jie Yang Wei Yang Shandong Engineering Research Center for Additive Manufacturing Qingdao University of TechnologyQingdao 266520People’s Republic of China State Key Laboratory of Polymer Materials Engineering College of Polymer Science and EngineeringSichuan UniversityChengdu 610065People’s Republic of China Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190People’s Republic of China

Effective thermal management is quite urgent for electronics owing to their ever-growing integration degree,operation frequency and power density,and the main strategy of thermal management is to remove excess energy from electronics to outside by thermal conductive *** to the conventional thermal management materials,flexible thermally conductive films with high in-plane thermal conductivity,as emerging candidates,have aroused greater interest in the last decade,which show great potential in thermal management applications of next-generation ***,a comprehensive review of flexible thermally conductive films is rarely ***,we review recent advances of both intrinsic polymer films and polymer-based composite films with ultrahigh in-plane thermal conductivity,with deep understandings of heat transfer mechanism,processing methods to enhance thermal conductivity,optimization strategies to reduce interface thermal resistance and their potential ***,challenges and opportunities for the future development of flexible thermally conductive films are also discussed.

关键词： Thermal conductivity Flexible thermally conductive films Heat transfer mechanism Interface thermal resistance Thermal management applications

Synthesis methods and powder quality of titanium monocarbide

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第8期72卷 10-18页

作者： Maoqiao Xiang Wenjun ding Qinghua Dong Qingshan zhu State Key Laboratory of Mesoscience and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of the Chinese Academy of SciencesBeijing 100049China Innovation Academy for Green Manufacture Chinese Academy of SciencesBeijing 100190China

Titanium monocarbide(TiC),which is the most stable titanium-based carbide,has attracted considerable interest in the fields of energy,catalysis,and structural materials due to its excellent *** of high-quality TiC powders with low cost and high efficiency is crucial for industrial applications;however major challenges face its ***,the methods for synthesizing TiC powders based on a reaction system are *** analysis is focused on the underlying mechanisms by which synthesis methods affect the quality of ***,strategies for improving the synthesis of highquality powders are analyzed from the perspective of enhancing heat and mass transfer ***,the critical issues,challenges,and development trends of the synthesis technology and application of high-quality TiC powder are discussed.

关键词： Titanium carbide Synthesis methods Reaction engineering Reaction kinetics Powder technology

Deep Reinforcement Learning Based Resource Allocation for fault Detection with Cloud Edge Collaboration in Smart Grid

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第3期10卷 1220-1230页

作者： Qiyue Li Yadong zhu Jinjin ding Weitao Li Wei Sun Lijian ding Hefei University of Technology Engineering Technology Research Center of Industrial Automation Hefei 230009China Electric Power Research Institute of State Grid Anhui Electric Power Co. Ltd.Hefei 230000China Hefei University of Technology Hefei 230009China IEEE CSEE

Real-time fault detection is important for operation of smart *** has become a trend of future development to design an anomaly detection system based on deep learning by using the powerful computing power of the ***,delay of Internet transmission is large,which may make the delay time of detection and transmission go beyond the ***,the edge-based scheme may not be able to undertake all data detection tasks due to limited computing resources of edge ***,we propose a cloud-edge collaborative smart grid fault detection system,next to which edge devices are placed,and equipped with a lightweight neural network with different precision for fault *** addition,a sub-optimal and realtime communication and computing resource allocation method is proposed based on deep reinforcement *** method greatly speeds up solution time,which can meet the requirements of data transmission delay,maximize the system throughput,and improve communication *** results show the scheme is superior in transmission delay and improves real-time performance of the smart grid detection system.

关键词： Cloud-edge collaboration communication delay deep reinforcement learning fault detection smart grid