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Ultrashort Pulse Generation at Quasi-40-GHz by Using a Two-Section Passively Mode-Locked InGaAsP-InP Tensile Strained Quantum-Well Laser

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Chinese Physics Letters 2012年第2期29卷 83-85页

作者： KONG Duan-Hua ZHU Hong-Liang LIANG Song qiu ji-fang ZHAO Ling-Juan Key Laboratory of Semiconductor Materials Science Institute of SemiconductorsChinese Academy of SciencesBeijing 100083

A 1.56 μm passively mode-locked laser diode with a two-section tensile strained multi-quantum-well structure is *** any external pulse compression,a Lorentz pulse train with a pulse width of 1.03 ps and a repetition rate of 35.6 GHz is obtained,which is one of the best results that have been reported on similar *** optical pulse has a 300 kHz line width and a 50dB peak over the noise floor in the photodetected radio-frequency electrical spectrum.

关键词： pulse passive Quantum

An InP-Based Dual-Depletion-Region Electroabsorption Modulator with Low Capacitance and Predicted High Bandwidth

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Chinese Physics Letters 2011年第11期28卷 124-127页

作者： SHAO Yong-Bo ZHAO Ling-Juan YU Hong-Yan qiu ji-fang qiu Ying-Ping PAN jiao-Qing WANG Bao-Jun ZHU Hong-Liang WANG Wei Key Laboratory of Semiconductor Materials Science Institute of SemiconductorsChinese Academy of SciencesP.O.Box 912Beijing 100083 School of Space Science and Physics Shandong University at WeihaiWeihai 264209

A novel dual-depletion-region electroabsorption modulator(DDR-EAM)based on InP at 1550nm is *** measured capacitance and extinction ratio of the DDR-EAM reveal that the dual depletion region structure can reduce the device capacitance significantly without any degradation of extinction ***,the bandwidth of the DDR-EAM predicted by using an equivalent circuit model is larger than twice the bandwidth of the conventional lumped-electrode EAM(L-EAM).

关键词： modulator extinction capacitance

Interface engineering enabled sintering-resistant metal nanocatalysts via reverse Ostwald ripening

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Science China Chemistry 2024年第9期67卷 2789-2791页

作者： Ying Sun Wenhui fang jieshan qiu Institute of Clean Energy Chemistry Key Laboratory for Green Synthesis and Preparative Chemistry of Advanced Materials of Liaoning ProvinceCollege of ChemistryLiaoning UniversityShenyang 110036China State Key Laboratory of Chemical Resource Engineering College of Chemical EngineeringBeijing University of Chemical TechnologyBeijing 100029China

The design and fabrication of advanced nanocatalysts with the high activity,selectivity,and superior durability remains a big challenge in industrial catalysis[1,2].The sintering of nanocatalysts under the thermally and/or chemically triggered conditions is a bottle-neck issue,which seriously decreases the amount of the exposed active sites and changes the original electronic structure of catalysts,resulting in the irreversible catalyst deactivation and high capital and time cost in industrial operation[3].

关键词： durability irreversible catalysis

Seasonal Variation of the Sea Surface Temperature Growth Rate of ENSO

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Advances in Atmospheric Sciences 2024年第3期41卷 465-477页

作者： Xinyi XING Xianghui fang Da PANG Chaopeng ji Department of Atmospheric and Oceanic Sciences and Institute of Atmospheric Sciences Fudan UniversityShanghai 200438China Shanghai Frontiers Science Center of Atmosphere-Ocean Interaction Shanghai 200438China Shanghai Key Laboratory of Ocean-land-atmosphere Boundary Dynamics and Climate Change Fudan UniversityShanghai 200438China

El Ni?o–Southern Oscillation(ENSO) exhibits a distinctive phase-locking characteristic, first expressed during its onset in boreal spring, developing during summer and autumn, reaching its peak towards winter, and decaying over the next spring. Several studies have demonstrated that this feature arises as a result of seasonal variation in the growth rate of ENSO as expressed by the sea surface temperature(SST). The bias towards simulating the phase locking of ENSO by many state-of-the-art climate models is also attributed to the unrealistic depiction of the growth rate. In this study, the seasonal variation of SST growth rate in the Ni?o-3.4 region(5°S–5°N, 120°–170°W) is estimated in detail based on the mixed layer heat budget equation and recharge oscillator model during 1981–2020. It is suggested that the consideration of a variable mixed layer depth is essential to its diagnostic process. The estimated growth rate has a remarkable seasonal cycle with minimum rates occurring in spring and maximum rates evident in autumn. More specifically, the growth rate derived from the meridional advection(surface heat flux) is positive(negative) throughout the year. Vertical diffusion generally makes a negative contribution to the evolution of growth rate and the magnitude of vertical entrainment represents the smallest contributor. Analysis indicates that the zonal advective feedback is regulated by the meridional immigration of the intertropical convergence zone, which approaches its southernmost extent in February and progresses to its northernmost location in September, and dominates the seasonal variation of the SST growth rate.

关键词： SST growth rate intertropical convergence zone zonal advective feedback mixed layer depth ENSO seasonal variation

Life forms affect beta-diversity patterns of larch forests in China

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Plant Diversity 2024年第1期46卷 49-58页

作者： Wenjing fang Qiong Cai Chengjun ji jiangling Zhu Zhiyao Tang jingyun fang School of Ecology and Environmental Science Yunnan UniversityKunming 650091China Department of Ecology College of Urban and Environmental Sciencesand Key Laboratory for Earth Surface Processes of the Ministry of EducationPeking UniversityBeijing 100871China

Beta-diversity reflects the spatial changes in community species composition which helps to understand how communities are assembled and biodiversity is formed and maintained. Larch(Larix) forests, which are coniferous forests widely distributed in the mountainous and plateau areas in North and Southwest China, are critical for maintaining the environmental conditions and species diversity. Few studies of larch forests have examined the beta-diversity and its constituent components(species turnover and nestedness-resultant components). Here, we used 483 larch forest plots to determine the total betadiversity and its components in different life forms(i.e., tree, shrub, and herb) of larch forests in China and to evaluate the main drivers that underlie this beta-diversity. We found that total betadiversity of larch forests was mainly dependent on the species turnover component. In all life forms,total beta-diversity and the species turnover component increased with increasing geographic, elevational, current climatic, and paleoclimatic distances. In contrast, the nestedness-resultant component decreased across these same distances. Geographic and environmental factors explained 20%-25% of total beta-diversity, 18%-27% of species turnover component, and 4%-16% of nestedness-resultant component. Larch forest types significantly affected total beta-diversity and species turnover component. Taken together, our results indicate that life forms affect beta-diversity patterns of larch forests in China, and that beta-diversity is driven by both niche differentiation and dispersal limitation. Our findings help to greatly understand the mechanisms of community assemblies of larch forests in China.

关键词： Beta-diversity Species turnover Nestedness-resultant Geographic distance Climatic distance Larch forest

Assessment and Enhancement of FRC of Power Systems Considering Thermal Power Dynamic Conditions

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1371-1383页

作者： Feng Hong Yalei Pang Weiming ji Lu Liang fang fang Junhong Hao jizhen Liu State Key Laboratory of Alternate Electric Power System with Renewable Energy Sources and School of Control and Computer Engineering North China Electric Power UniversityBeijing 102206China State Key Laboratory of Alternate Electric Power System with Renewable Energy Sources School of Energy Power and Mechanical EngineeringNorth China Electric Power UniversityBeijing 102206China

Frequency stability and security have been a vital challenge as large-scale renewable energy is integrated into power *** contrast,the proportion of traditional thermal power units decreases during the decarbonization transformation process,resulting in poor frequency *** paper aims to explore the potential of frequency regulation support,dynamic assessment,and capacity promotion of thermal power plants in the transition *** the dynamic characteristics of the main steam working fluid under different working conditions,a nonlinear observer is constructed by extracting the main steam pressure and valve opening degree *** real-time frequency modulation capacity of thermal power units can provide a dynamic state for the power grid.A dynamic adaptive modification for primary frequency control(PFC)of power systems,including wind power and thermal power,is proposed and *** power dynamic allocation factor is adaptively optimized by predicting the speed droop ratio,and the frequency modulation capability of the system is improved by more than 11%under extreme ***,through the Monte Carlo simulation of unit states of the system under various working conditions,the promotion of the frequency regulation capacity with high wind power penetration(WPP)is verified.

关键词： Dynamic evaluation frequency regulation power system predictive modeling wind penetration

流动性经验和理性医疗选择——基于高龄孕妇的个案分析

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妇女研究论丛 2017年第1期 21-29页

作者：邱济芳南京大学社会学院江苏南京210023

文章以生育政策调整为社会背景,分析高龄女性决定生育二孩与产前检查的过程,探讨当前城市高龄二孩孕妇对高龄生育风险的认知及其应对孕产医学化的行动策略。研究发现,高龄女性在医疗服务使用中表现出流动性的主体经验和理性的医疗选择... 详细信息

文章以生育政策调整为社会背景,分析高龄女性决定生育二孩与产前检查的过程,探讨当前城市高龄二孩孕妇对高龄生育风险的认知及其应对孕产医学化的行动策略。研究发现,高龄女性在医疗服务使用中表现出流动性的主体经验和理性的医疗选择策略。面对孕产医学化的标准和检查,高龄女性依靠主观身体经验调整自己的风险认知,逐渐习得医学知识从而理性选择产前检查。这一过程中,高龄女性学会了使用医院专业术语,形成了理性的医疗实践策略,同时也成了网络媒体中的"平民专家"。

关键词：流动性经验理性医疗选择高龄孕妇医学化

A Mode-switching Strategy of Droop Control for VSC-MTDC Systems Considering Maximum DC Voltage Regulation Capability

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 903-912页

作者： Yizhen Wang Fengliang qiu Zhongguan Wang Yirun ji Zhengguang Chen Chengshan Wang Key Laboratory of Smart Grid of Ministry of Education Tianjin UniversityTianjin 300072China Electric Power Research Institute of State Grid jiBei Electric Power Co.Ltd. Beijing 100045China State Grid Corporation of China Beijing 100031China IEEE

To achieve the goal of carbon neutrality,renewable energy integration through a voltage source converter based multi-terminal direct current(VSC-MTDC)system has been identified as a promising *** tackle the significant DC voltage over-limit problem in a VSC-MTDC system during disturbances,this paper proposes a mode-switching strategy of droop control considering maximum DC voltage regulation *** close relationship between node injection powers and node DC voltages in the MTDC system is elaborated,and the most effective regulation approach of local injection power for limiting DC voltage deviation is *** operating point trajectories of different droop control explains that the DC voltage deviation can be minimized by fully utilizing the capacity of ***,the mode-switching strategy with the maximum DC voltage regulation capability is realized by the switching between the voltage droop control and the constant maximum power *** addition,a mode recovery process and a smooth switching method are developed to make converters regain the capability of maintaining DC voltage and reduce power fluctuation during mode switching,***,three cases are investigated to verify the effectiveness of the proposed mode-switching *** with simulation results of the conventional droop control and the DC voltage deviation-dependent droop control,better performance of transient and steady-state DC voltage deviation is achieved through the proposed strategy.

关键词： Droop control maximum DC voltage regulation capability mode-switching VSC-MTDC

How Does Stacking Pressure Affect the Performance of Solid Electrolytes and All-Solid-State Lithium Metal Batteries?

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Energy & Environmental Materials 2024年第4期7卷 93-98页

作者： Junwu Sang Bin Tang Yong qiu Yongzheng fang Kecheng Pan Zhen Zhou Interdisciplinary Research Center for Sustainable Energy Science and Engineering (IRC4SE2) School of Chemical Engineering Zhengzhou University

All-solid-state lithium metal batteries (ASSLMBs) with solid electrolytes (SEs)have emerged as a promising alternative to liquid electrolyte-based Li-ion batteries due to their higher energy density and ***,since ASSLMBs lack the wetting properties of liquid electrolytes,they require stacking pressure to prevent contact loss between electrodes and SEs.

关键词： critical current density solid electrolyte solid-state lithium metal batteries stacking pressure