检索结果-南通市图书馆

China Ocean Engineering 2020年第5期34卷 597-607页

作者： CAI Bao-ping ZHANG Yan-ping YUAN Xiao-bing GAO Chun-tan liu Yong-hong CHEN Guo-ming liu zeng-kai JI Ren-jie National Engineering Laboratory of Offshore Geophysical and Exploration Equipment China University of PetroleumQingdao 266580China College of Mechanical and Electronic Engineering China University of PetroleumQingdao 266580China

Under unanticipated natural disasters, any failure of structure components may cause the crash of an entire structure system. Resilience is an important metric for the structure system. Although many resilience metrics and assessment approaches are proposed for engineering system, they are not suitable for complex structure systems, since the failure mechanisms of them are different under the influences of natural disasters. This paper proposes a novel resilience assessment metric for structure system from a macroscopic perspective, named structure resilience, and develops a corresponding assessment approach based on remaining useful life of key components. Dynamic Bayesian networks(DBNs) and Markov are applied to establish the resilience assessment model. In the degradation process, natural degradation and accelerated degradation are modelled by using Bayesian networks, and then coupled by using DBNs. In the recovery process, the model is established by combining Markov and DBNs. Subsea oil and gas pipelines are adopted to demonstrate the application of the proposed structure metric and assessment approach.

关键词： structure resilience structure system remaining useful life dynamic Bayesian networks

Recurrent atrial tachycardia and atrial fribrillation after circumferential pulmonary vein ablation:What’s the difference?

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2005年第21期118卷 1773-1778页

作者： liu Xing-peng LONG De-yong DONG Jian-zeng liu Xiao-qing FANG Dong-ping HAO Peng MA Chang-sheng Department of Cardiology Beijing Anzhen Hospital Capital University of Medical Science Beijing 100029 China

Background Recurrent atrial tachyarrhythmia （ATa） after circumferential pulmonary vein ablation （CPVA） includes atrial tachycardia （AT） and atrial fribrillation （AF）. However, whether there are some differences in clinical course and mechanisms between the recurrent AT and the recurrent AF remained unclear. This study was conducted to investigate the incidence, mechanism, clinical course of the recurrent AT and AF in patients under *** One hundred and thirty consecutive patients （M/F = 95/35 ） with highly symptomatic ano multiple antiarrhythmic drugs （AADs） refractory paroxysmal （ n = 91 ） or persistent （ n = 39 ） AF were included. The ablation protocol consisted solely of two continuous circular lesions around the ipsilateral pulmonary veins （PV） guided by CARTO system. The endpoint of CPVA is PV isolation. For patients with recurrent ATa within 2 months after the initial procedure, cardioversion with direct current was attempted if the ATa lasted for more than 24 hours. A repeat ablation procedure was performed only for patients with AADs refractory recurrent ATa and at least followed up for 2 months after the initial *** Within 2 months after the initial procedure, 52 patients （40. 0% ） had experienced episodes of symptomatic recurrent ATa. Among them, 23 patients （44.2%） with recurred AT alone （AT group ）, 14 patients （26.9%） with recurred AF alone （AF group）, and 15 patients （28.8%） with recurred AT and AF （AT plus AF group）. The delayed cure rate （65.2%） in AT group was significant higher than that in AF group （21.4%, P〈0.05） and AF plus AT group （26.7%, P 〈0.05）. A repeat ablation was performed in 21 patients, including 6 patients with recurrent AT alone, 8 patients with recurrent AF alone, and 7 patients with recurrent AF plus AT. The mean number of PV gaps was 1.2 ± 0. 4 in AT group, which was significantly lower than that in AF group （2.6 ± 0. 7, P 〈 0.05） and AF plus AT group （2.0 ± 0.6, P 〈 0.05）. Delayed cure rate and number of PV

关键词： atrial fibrillation catheter ablation pulmonary vein

High responsivity and fast response 8×8β-Ga_(2)O_(3)solar-blind ultraviolet imaging photodetector array

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2023年第11期66卷 3259-3266页

作者： SHEN GaoHui liu zeng TANG Kai SHA ShuLin LI Lei TAN Chee-Keong GUO YuFeng TANG WeiHua Innovation Center of Gallium Oxide Semiconductor(IC-GAO) College of Integrated Circuit Science and EngineeringNanjing University of Posts and TelecommunicationsNanjing 210023China National and Local Joint Engineering Laboratory for RF Integration and Micro-Assembly Technologies Nanjing University of Posts and TelecommunicationsNanjing 210023China Key Laboratory of Aerospace Information Materials and Physics(NUAA) MIITNanjing 211106China College of Physics MIIT Key Laboratory of Aerospace Information Materials and PhysicsKey Laboratory for Intelligent Nano Materials and DevicesNanjing University of Aeronautics and AstronauticsNanjing 211106China Advanced Materials Thrust Function HubThe Hong Kong University of Science and Technology(Guangzhou)Nansha 511458China Department of Electronic and Computer Engineering School of EngineeringThe Hong Kong University of Science and TechnologyHong Kong 999077China

In this work,an 8×8 Ga_(2)O_(3)solar-blind ultraviolet photodetector array is introduced for image sensing *** 2-in wafer-scaled Ga_(2)O_(3)thin film was grown by metalorganic chemical vapor deposition technique;and the photodetector array was fabricated through ultraviolet photolithography,lift-off,and electron-beam *** addition to the high solar-blind/visible rejection ratio of 104,every photodetector cell in the array has high performance and fast response speed,such as responsivity of 49.4 A W^(-1),specific detectivity of 6.8×10^(14)Jones,external quantum efficiency of 1.9×10^(4)%,linear dynamic range of 117.8 d B,and response time of 41 ms,respectively,indicating the high photo-response performance of the ***,the photodetector array displayed uniform responsivity with a standard deviation of~6%,and presented a sensing image of low chromatic aberration,owing to the high resolution of the photodetector *** a word,this work may contribute to developing Ga_(2)O_(3)-based optoelectronic device applications.

关键词： Ga_(2)O_(3) photodetector array imaging photo-response

Printed Biosensors for the Detection of Alzheimer’s Disease Based on Blood Biomarkers

在线全文

学校读者我要写书评

暂无评论

Journal of Analysis and Testing 2024年第2期8卷 133-142页

作者： Yu zeng Zhen Huang Yibiao liu Tailin Xu Longgang Central Hospital of Shenzhen Shenzhen518116China School of Biomedical Engineering Shenzhen UniversityShenzhen518060China

Alzheimer’s disease(AD)is a chronic neurodegenerative disorder,and early diagnosis plays a crucial role in its prevention and *** recent years,blood-based biomarkers for early AD diagnosis have gained attention due to their non-invasiveness and minimal adverse reactions,which make them an attractive *** the onset of the COVID-19 pandemic,visiting large medical examination centers for blood tests has become increasingly *** trend is shifting towards community or home-based sampling,which relies on the development and application of portable,miniaturized,and highly sensitive *** the various sensors used for detecting blood biomarkers in AD,printed sensors demonstrate great potential in AD blood biomarker detection due to their ease of miniaturization,scalability for mass production,and compatibility with various detection *** this review,we focus on discussing the application of printed sensors in the analysis of blood biomarkers for *** also explore the challenges faced by printed sensors in early diagnosis based on AD blood biomarkers and propose potential solutions to address these challenges.

关键词： Printed biosensors Alzheimer’s disease Blood biomarkers Printing technology

Effects of soil crust on the collapsing erosion of colluvial deposits with granite residual soil

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第8期21卷 2579-2591页

作者： liu Weiping zeng Bohan WANG Tianhuan DUAN Junyi School of Infrastructure Engineering Nanchang UniversityNanchang 330031China

Collapsing erosion is a unique phenomenon commonly observed on the granite residue hillslopes in the tropical and subtropical regions of southern China,characterized by its abrupt occurrence and significant erosion ***,the impacts of soil crust conditions on the erosion of colluvial deposits with granite residual soils have only been studied to a limited *** address this issue,this study investigates the impacts of three soil crust conditions(i.e.,without crust,10-minute crust,and 20-minute crust)on gully morphology,rainfall infiltration,and runoff and sediment yield during slope erosion of colluvial deposits with granite residues(classified as Acrisols)in Yudu County,Ganzhou City,Jiangxi Province,China,using simulated rainfall tests and photographic *** results showed that as the strength of the soil crust increased,the capacity of moisture infiltration and the width and depth of the gully as well as the sediment concentration and yield ratio decreased;at the same time,the runoff ratio *** sediment yield in the without-crust test was found to be 1.24 and 1.43 times higher than that observed in the 10-minute crust and 20-minute crust tests,*** results indicate that soil crusts can effectively prevent slope erosion and moisture infiltration,while providing valuable insights for the management of soil erosion in natural environments.

关键词： Granite residual soil Colluvial deposits Slope erosion Soil crust Sediment yield

mc-Si:H/c-Si solar cell prepared by PECVD

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2006年第z1期25卷 176-179页

作者： XU Ying LIAO Xianbo DIAO Hongwei Li Xudong zeng Xiangbo liu Xiaoping WANG Minhua WANG Wenjing State Laboratory for Surface Physics Institute of Semiconductors and Center for Condensed Matter Physics Chinese Acad-bmy of Sciences Beijing 100083 China Beijing Solar Energy Research Institute Beijing 100083 China State Laboratory for Surface Physics Institute of Semiconductors and Center for Condensed Matter Physics Chinese Acad-bmy of Sciences Beijing 100083 China State Laboratory for Surface Physics Institute of Semiconductors and Center for Condensed Matter Physics Chinese Acad-bmy of Sciences Beijing 100083 China Beijing Solar Energy Research Institute Beijing 100083 China State Laboratory for Surface Physics Institute of Semiconductors and Center for Condensed Matter Physics Chinese Acad-bmy of Sciences Beijing 100083 China Beijing Solar Energy Research Institute Beijing 100083 China Beijing Solar Energy Research Institute Beijing 100083 China Beijing Solar Energy Research Institute Beijing 100083 China

Hetero-junction solar cells with an mc-Si:H window layer were achieved. The open voltage is increased while short current is decreased with increasing the mc-Si:H layer′s thickness of emitter layer. The highest of Voc of 597 mV has obtained. When fixed the thickness of 30 nm, changing the N type from amorphous silicon layer to micro-crystalline layer, the efficiency of the hetero-junction solar cells is increased. Although the hydrogen etching before deposition enables the c-Si substrates to become rough by AFM images, it enhances the formation of epitaxial-like micro-crystalline silicon and better parameters of solar cell can be obtained by implying this process. The best result of efficiency is 13.86% with the Voc of 549.8 mV, Jsc of 32.19 mA·cm-2 and the cell′s area of 1 cm2.

关键词： solar cell hetero-junction amorphous silicon plasma enhanced CVD

Pure Rotational Spectrum of Dibenzofuran in Range of 2-6 GHz

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2020年第1期33卷 125-128,I0078-I0083页

作者： Hai-hua Zhou zeng-kui liu Zi-qiu Chen Ming Sun Qian Chen Sheng-wen Duan Chao Jiao College of Chemistry and Chemical Engineering Lanzhou UniversityLanzhou 730000China School of Electronic and Optical Engineering Nanjing University of Science and TechnologyNanjing 210094China

We report the observation and assignment of the rotational spectra of dibenzofuran measured in the range of 2-6 GHz with a newly constructed broadband chirped-pulse Fourier transform microwave(cp-FTMW)*** analysis of the microwave spectra led to the assignment of 40 b-type transitions,resulting in the accurate determination of the rotational constants A=2278.19770(38)MHz,B=601.12248(10)MHz,and C=475.753120(98)MHz.

关键词： Dibenzofuran Polycyclic aromatic hydrocarbons Broadband rotational spectroscopy

Influence of Vanes and Blades on Ingress in Axial Rim Seal for Turbine Stages

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2024年第3期33卷 833-846页

作者： REN Ran DU Qiang liu Guang zeng Yanlian XIE Lei Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China National Key Laboratory of Science and Technology on Advanced Light-duty Gas-turbine Beijing100190China School of Aeronautics and Astronautics University of Chinese Academy of SciencesBeijing100190China

Hot gas ingestion refers to the phenomenon of mainstream hot gas flowing into the space cavity of a turbine *** studies have found that mainstream annulus pressure distribution plays an important role in hot gas ingestion,but due to its complexity,the mechanism of the interaction between mainstream flow and hot gas ingestion remains *** paper adopts the URANS method,and three sealing flow rates are considered,named C_(w)=0,C_(w)=500,and C_(w)=*** time-averaged annulus pressure distribution shows that an increase in the sealing flow decreases the pressure value,and the effects of the sealing flow on the pressure distribution of the leading edge of the blade are much more influential than that of the trailing edge of the *** unsteady pressure time-space distribution in the annulus indicates that a time-space tilted distribution of pressure at the rim exits when the sealing flow *** phenomenon is mainly due to the strong feedback mechanism of the sealing flow to the annulus pressure field.A comparison of the pressure and mean radial velocity distribution of the mainstream shows that the ingestion mainly occurs on the blade side,where the pressure is lower than on the vane *** flow characteristics at the wheel rim are analyzed with a sealing flow rate C_(w)=5000,and under these conditions,both pressure-induced ingestion and ingestion caused by a passage vortex can be *** three-dimensional and inertial effects of the mainstream at the wheel rim lead to the generation of separation vortices on the blade side,and the presence of separation vortices leads to ingestion along the blade *** the same time,pressure on the blade side will cause the fluid to have a radial inward flow tendency,which will promote the formation of separation vortices,leading to more serious ingestion in the high-pressure region on the blade *** blade pressure field can be more significant than the vane trailing pressure field in the rim sea

关键词： separation vortex unsteady rim seal the effect of blade on ingestion

Capacitor Voltage Imbalance Mechanism and Balancing Control of MMC When Riding Through PTG Fault

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2期10卷 778-785页

作者： Zhen He Maozeng Lu Lijun Hang Pingliang zeng Yanhua liu Hangzhou Dianzi University Hangzhou 310018China Shandong University of Technology Zibo 255000China State Grid Hangzhou Power Supply Company State GridHangzhou 310000China

Modular multilevel converter (MMC) based fault ride through (FRT) control is a promising solution to deal with the pole-to-ground (PTG) fault in high voltage direct current (HVDC) system. However, when MMC switches to the FRT control, capacitor voltage imbalance between upper and lower arms will occur, resulting in the deterioration of FRT performance. This letter provides a comprehensive analysis for the imbalance issue from the perspective of fundamental frequency circulating current (FFCC). It is found the imbalance during FRT stage will not expand continuously, but converge to a certain value gradually. The specific imbalance degree is closely associated with the amplitude of FFCC. In order to solve the imbalance issue, an open-loop balancing control is proposed. By introducing a fundamental frequency feedforward item to the inherent circulating current control, the proposed method can not only balance the capacitor voltages, but also minimize the amplitude of FFCC, and consequently the power loss of MMC during FRT process can be reduced. Finally, simulation results of PSCAD/ EMTDC verify the validity of theoretical analysis.

关键词： Balancing control capacitor voltage imbalance FFCC FRT control HVDC system PTG fault

Optimal Stochastic Scheduling Strategy of Multi-vector Energy Complex Integrated with Full-blown Power-to-biomethane Model

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

Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 863-873页

作者： Guanwei zeng Chengxi liu Minfang Liao Yongjian Luo Xuzhu Dong Hubei Engineering and Technology Research Center for AC/DC Intelligent Distribution Network WuhanChina the School of Electrical Engineering and Automation Wuhan UniversityWuhanChina

We propose an optimal stochastic scheduling strategy for a multi-vector energy complex(MEC),considering a fullblown model of the power-to-biomethane(Pt M)*** conventional optimization that uses a simple efficiency coefficient to coarsely model energy conversion between electricity and biomethane,a detailed Pt M model is introduced to emphasize the reactor kinetics and chemical equilibria of *** model crystallizes the interactions between the Pt M process and MEC flexibility,allowing to adjust the operating condition of the methanation reactor for optimal MEC operation in stochastic *** optimization and flowsheet design of the Pt M process increase the average selectivity of methane(i.e.,ratio between net biomethane production and hydrogen consumption)up to 83.7%in the proposed synthesis *** results can provide information and predictions to operators about the optimal operating conditions of a Pt M unit while improving the MEC flexibility.

关键词： Multi-vector energy complex optimal stochastic scheduling power-to-biomethane unit process synthesis natural gas