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Journal of Semiconductors 2023年第11期44卷 52-58页

作者： Yunshan Zhang Yifan Xu shijian guan Jilin Zheng Hongming Gu Lianyan Li Rulei Xiao Tao Fang Hui Zou Xiangfei Chen College of Electronic and Optical Engineering and College of Flexible Electronics(Future Technology) Nanjing University of Posts and TelecommunicationsNanjing 210023China College of Engineering and Applied Sciences Nanjing UniversityNanjing 210023China College of Communications Engineering PLA Army Engineering UniversityNanjing 210007China

Modulation bandwidth enhancement in a directly modulated two-section distributed feedback(TS-DFB)laser based on a detuned loading effect is investigated and experimentally *** results show that the 3-dB bandwidth of the TS-DFB laser is increased to 17.6 GHz and that chirp parameter can be reduced to *** to the absence of a detuned loading effect,there is a 4.6 GHz increase and a 2.45 reduction,*** transmitting a 10 Gb/s non-return-to-zero(NRZ)signal through a 5-km fiber,the modulation eye diagram still achieves a large ***-channel laser arrays with precise wavelength spacing are *** TS-DFB laser in the array has side mode suppression ratios(SMSR)>49.093 dB and the maximum wavelength residual<0.316 nm.

关键词： distributed feedback(DFB)laser detuned loading effect direct modulation

The role of oceanic feedbacks in the 2014–2016 El Niño events as derived from ocean reanalysis data

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Journal of Oceanology and Limnology 2020年第5期38卷 1394-1407页

作者： guan Cong WANG Fan HU shijian Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of SciencesQingdao 266071China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China Pilot National Laboratory for Marine Science and Technology(Qingdao) Qingdao 266237China College of Marine Science University of Chinese Academy of SciencesQingdao 266400China

Why did the predicted“super El Niño”fade out in the summer 2014 and the following year develop into one of the three strongest El Niño on record?Although some hypotheses have been proposed in previous studies,the quantitative contribution of oceanic processes to these events remains *** investigated the role of various oceanic feedbacks,especially in response to intra-seasonal westerly wind busts,in the evolution of the 2014–2016 El Niño events,through a detailed heat budget analysis using high temporal resolution Estimating the Circulation and Climate of the Ocean—Phase II(ECCO2)simulation outputs and satellite-based *** show that the Ekman feedback and zonal advective feedback were the two dominant oceanic processes in the developing phase of the warm event in the spring of 2014 and its decay in *** the 2015–2016 super El Niño event,the zonal advective feedback and thermocline feedback played a signifi cant role in the eastern Pacifi c ***,the thermocline feedback tended to weaken in the central Pacifi c where the zonal advection feedback became the dominant positive feedback.

关键词： El Niño-Southern Oscillation(ENSO) extreme El Niño zonal advective feedback thermocline feedback Ekman feedback inter-seasonal variability

Long-term ultrastable frequency dissemination via a 50-km spooled fiber link using a two-section DFB laser

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Chinese Optics Letters 2024年第1期22卷 164-169页

作者：尹知谦张川博管世健周昕王亚光王磊磊郑满航刘奕彤张云山朱兴邦方涛陈向飞 Engineering Research Center of Precision Photonics Integration and System Application Ministry of Education&Key Laboratory of Intelligent Optical Sensing and ManipulationMinistry of Education&National Laboratory of Solid State Microstructures&College of Engineering and Applied Sciences&Institute of Optical Communication Engineering&Nanjing University-Tongding Joint Lab for Large-Scale Photonic Integrated CircuitsNanjing UniversityNanjing 210023China College of Electronics and Optical Engineering and College of Flexible Electronics Nanjing University of Posts and TelecommunicationsNanjing 210023China The 41st Research Institute of China Electronics Technology Group Corp Qingdao 266000China

The stable long-distance transmission of radio-frequency(RF)signals holds significant importance from various aspects,including the comparison of optical frequency standards,remote monitoring and control,scientific research and experiments,and RF spectrum *** demonstrate a scheme where an ultrastable frequency signal was transmitted over a 50 km coiled *** optical RF signal is generated using a two-section distributed feedback(DFB)laser for direct modulation based on the reconstruction equivalent chirp(REC)*** 3-dB modulation bandwidth of the two-section DFB laser is 18 GHz and the residual phase noise of-122.87 dBc/Hz is achieved at 10-Hz offset *** report a short-term stability of 1.62×10^(-14)at an average time of 1 s and a long-term stability of 6.55×10^(-18)at the measurement time of 62,000 s when applying current to the front section of the DFB *** applying power to both sections,the stability of the system improves to 4.42×10^(-18)within a testing period of 56,737 *** applying temperature variations to the transmission link,long-term stability of 8.63×10^(-18)at 23.9 h can still be achieved.

关键词： frequency dissemination two-section DFB laser phase stability

Stability-enhanced RF signal transmission over long fiber-optic links

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Chinese Optics Letters 2024年第5期22卷 131-136页

作者：尹知谦郑满航张川博管世健周昕刘奕彤刚泽宇聂佳强张云山朱兴邦方涛陈向飞 Engineering Research Center of Precision Photonics Integration and System Application Ministry of Education&Key Laboratory of Intelligent Optical Sensing and ManipulationMinistry of Education&National Laboratory of Solid State Microstructures&College of Engineering and Applied Sciences&Institute of Optical Communication Engineering&Nanjing University-Tongding Joint Lab for Large-scale Photonic Integrated CircuitsNanjing UniversityNanjing 210023China College of Electronics and Optical Engineering and College of Flexible Electronics(Future Technology) Nanjing University of Posts and TelecommunicationsNanjing 210023China The 41st Research Institute of China Electronics Technology Group Corp Qingdao 266000China

We propose a method for optimizing the phase stability of microwave signal transmission over long ***,the design of the photon link was modified to reduce the radio frequency(RF)signal’s baseline noise and increase ***,a low-noise driver circuit was developed for a two-section distributed feedback(DFB)laser designed using reconstruction equivalent chirp(REC)technology to create an ultra-stable laser,and its performance was characterized through linewidth *** results indicate that the DFB laser achieved narrower linewidth,improving system phase *** an injection current(30 mA)is applied to the reflection section of the two-section DFB laser,the laser linewidth will be narrower(1.38 MHz),further enhancing the system’s phase transmission *** a 1 Hz offset frequency,a residual phase noise of-88.65 dBc/Hz is *** short-term stability with an averaging time of 1 s is 1.60×10^(-14),and the long-term stability over a testing time of 60,000 s is 3.41×10^(-18).Even after incorporating temperature variations,the long-term stability reaches 8.37×10^(-18) at 22 h.

关键词： frequency dissemination two-section distributed feedback laser phase stability

Cooperative effect of Cr and Al elements on passivation enhancement of eutectic high-entropy alloy AlCoCrFeNi_(2.1)with precipitates

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Journal of Materials Science & Technology 2023年第5期136卷 97-108页

作者： Xiaotian Duan Tiezhuang Han Xiao guan Yuning Wang Huhu Su Kaisheng Ming Jing Wang shijian Zheng State Key Laboratory of Reliability and Intelligence of Electrical Equipment Hebei University of TechnologyTianjin 300130China School of Material Science and Engineering Hebei University of TechnologyTianjin 300130China

In conventional corrosion-resistant alloys,precipitation usually reduces corrosion resistance severely by weakening passive films *** this work,we found that the aging-treated AlCoCrFeNi_(2.1)sam-ples,which have abundant nanosized L 12 and body-centered cubic(BCC)precipitates in the lamellar face-centered cubic(FCC)and B2 phases,displayed better corrosion resistance than solution-treated AlCoCrFeNi_(2.1)samples without *** the AlCoCrFeNi_(2.1)alloy,the FCC phase with L1_(2)precipi-tates and the B2 phase with BCC precipitates were protected by passive films enriched with Cr and Al elements,***,the Al-rich passive film of the B2 phase was less stable than the Cr-rich passive film of the FCC phase,so B2 phase dissolved *** Cr-rich passive film of the FCC phase remained stable with the formation of Al-rich L1_(2)precipitates inside the phase because those precipitates with the size of∼5 nm were too small to affect the composition of the Cr-rich passive *** formation of Cr-rich BCC precipitates within the B2 phase increased the content of the Al element inside the phase,improving the stability of Al-rich passive film on the B2 ***,BCC precip-itates with the size of∼30 nm were protected by Cr-rich passive film,which could inhibit the expansion of corrosion ***,the corrosion resistance of eutectic high-entropy alloy AlCoCrFeN 2.1 was unprece-dentedly enhanced by the precipitation of BCC *** study could provide an attractive strategy for designing high-entropy alloys with excellent corrosion resistance and high strength.

关键词： Eutectic high-entropy alloy Passive film Corrosion resistance Precipitates TEM

Multi-decadal trends in the tropical Pacific western boundary currents retrieved from historical hydrological observations

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Science China Earth Sciences 2021年第4期64卷 600-610页

作者： shijian HU Xi LU Shihan LI Fan WANG Cong guan Dunxin HU Linchao XIN Jie MA CAS Key Laboratory'of Ocean Circulation and Waves Institute of OceanologyChinese Academy of SciencesQingdao 266071China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China Pilot National Laboratory for Marine Science and Technology(Qingdao) Qingdao 266237China College of Marine Science University of Chinese Academy of SciencesQingdao 266071China

As large-scale ocean circulation is a key regulator in the redistribution of oceanic energy, evaluating the multi-decadal trends in the western Pacific Ocean circulation under global warming is essential for not only understanding the basic physical processes but also predicting future climate change in the western Pacific. Employing the hydrological observations of World Ocean Atlas 2018(WOA18) from 1955 to 2017, this study calculated the geostrophic currents, volume transport and multidecadal trends for the North Equatorial Current(NEC), the North Equatorial Countercurrent(NECC), the Mindanao Current(MC), the Kuroshio Current(KC) in the origin and the New Guinea Coastal Undercurrent(NGCUC) within tropical western Pacific Ocean over multi-decades. Furthermore, this study examined the contributions of temperature and salinity variations. The results showed significant strengthening trends in NEC, MC and NGCUC over the past six decades, which is mainly contributed by temperature variations and consistent with the tendency in the dynamic height pattern. Zonal wind stress averaged over the western Pacific Ocean in the same latitude of each current represents the decadal variation and multi-decadal trends in corresponding ocean currents, indicating that the trade wind forcing plays an important role in the decadal trend in the tropical western Pacific circulation. Uncertainties in the observed hydrological data and trends in the currents over the tropical western Pacific are also discussed. Given that the WOA18 dataset covers most of the historical hydrological sampling data for the tropical western Pacific, this paper provides important observational information on the multi-decadal trend of the large-scale ocean circulation in the western Pacific.

关键词： Pacific Western boundary current Multi-decadal trend Global variation Hydrological observation

南京北郊大气垂直扩散参数特征的测量及其应用

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气象与环境科学 2018年第4期41卷 54-59页

作者：曹琪敏邹嘉南马欣於清源魏夏潞官石坚张秀美安俊琳南京信息工程大学气象灾害教育部重点实验室气候与环境变化国际合作联合实验室气象灾害预报预警与评估协同创新中心中国气象局气溶胶与云降水重点开放实验室南京210044 中山大学大气科学学院广州510275 兰州大学大气科学学院半干旱气候变化教育部重点实验室兰州730000

利用平面照相法,以江苏南热发电有限责任公司#Q2号烟囱为研究对象,进行了500次拍摄,通过风向风速、云量、太阳高度角等气象数据,确定了不同稳定度下南京北郊大气扩散参数的特征。与P-G扩散曲线对比发现,在强不稳定A、弱不稳定C、中性D... 详细信息

利用平面照相法,以江苏南热发电有限责任公司#Q2号烟囱为研究对象,进行了500次拍摄,通过风向风速、云量、太阳高度角等气象数据,确定了不同稳定度下南京北郊大气扩散参数的特征。与P-G扩散曲线对比发现,在强不稳定A、弱不稳定C、中性D层结中,南京北郊的大气垂直扩散参数在距离排放源200 m范围内更不稳定,而在200—1000 m范围内更稳定。其中,不稳定B层结的扩散曲线与P-G扩散曲线一致,较稳定E、稳定F层结出现于白天的频率很低。对比垂直扩散参数幂函数表达式σ_z=γx~α的系数值γ和α,本研究中α值分别比国家标准增加了28. 6%(A层结)、56. 4%(C层结)、30. 4%(D层结),而B层结的α值却比国家标准减少了22. 9%。此外,通过高斯扩散公式计算得到SO_2和NO_X扩散到观测点的浓度,发现该计算值仅占气象楼污染气体监测平台实测SO_2和NO_X浓度的0. 82%和0. 69%。结合风场发现,SO_2和NO_X实测值受观测点东部工业污染物排放的叠加效应影响较大。其中,NO_X的实测值在受到偏东风和偏南风的影响时具有较大值,且在0. 5～1. 5 m·s^(-1)的较弱风速影响时,NO_X的实测值将达到60μg·m^(-3)以上。

关键词：南京大气扩散参数高斯扩散模式

Dynamic features of near-inertial oscillations in the Northwestern Pacific derived from mooring observations from^2015 to 2018

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Journal of Oceanology and Limnology 2020年第4期38卷 1092-1107页

作者： HU shijian LIU Lingling guan Cong ZHANG Linlin WANG Jianing WANG Qingye MA Jie WANG Fujun JIA Fan FENG Junqiao LU Xi WANG Fan HU Dunxin CAS Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of SciencesQingdao 266071China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China Pilot National Laboratory for Marine Science and Technology(Qingdao) Qingdao 266237China College of Marine Science University of Chinese Academy of SciencesQingdao 266071China

Near-inertial oscillation is an important physical process transferring surface wind energy into deep *** investigated the near-inertial kinetic energy(NIKE)variability using acoustic Doppler current profiler measurements from a mooring array deployed in the tropical western Pacific Ocean along 130°E at 8.5°N,11°N,12.6°N,15°N,and 17.5°N from September 2015 to January *** features,decay timescales,and significant seasonal variability of the observed NIKE were *** the mooring sites of 17.5°N,15°N,and 12.6°N,the NIKE peaks occurred in boreal autumn and the NIKE troughs were observed in boreal *** contrast,the NIKE at 11°N and 8.5°N showed peaks in winter and troughs in *** cyclones and strong wind events played an important role in the emergence of high-NIKE events and explained the seasonality and latitudinal characteristics of the observed NIKE.

关键词： near-inertial kinetic energy western Pacific Ocean tropical cyclones mooring array seasonal variability

基于整体最小二乘的地面激光扫描标靶球定位方法

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大地测量与地球动力学 2009年第4期29卷 102-105页

作者：鲁铁定周世健张立亭官云兰东华理工大学地球科学与测绘工程学院抚州344000 武汉大学测绘学院武汉430079 江西省科学院南昌330029

通过分析标靶球定位的最小二乘定位方法及其存在的问题,提出了一种地面激光扫描标靶球定位的整体最小二乘标靶球定位方法,并推导给出了两种整体最小二乘解算法,该方法可同时考虑系数矩阵误差的影响。利用真实数据进行验证的结果表明:整... 详细信息

通过分析标靶球定位的最小二乘定位方法及其存在的问题,提出了一种地面激光扫描标靶球定位的整体最小二乘标靶球定位方法,并推导给出了两种整体最小二乘解算法,该方法可同时考虑系数矩阵误差的影响。利用真实数据进行验证的结果表明:整体最小二乘法比最小二乘法能够得到精度更高的解算结果,有利于提高标靶球体定位的准确度。

关键词：地面激光扫描标靶球拟合点云整体最小二乘

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日光温室平板微热管阵列蓄热墙体热性能试验

农业工程学报 2021年第3期37卷 205-212页

作者：管勇王天梅魏铭佟柳天明胡万玲段世检兰州交通大学环境与市政工程学院兰州730070

为提高日光温室复合结构墙体热稳定层的温度并提升温室墙体材料的蓄热性能,该研究提出一种新型日光温室平板微热管阵列蓄热墙体(Micro Heat Pipe Array,MHPA),搭建了小型MHPA墙体温室试验台,采用对比试验的方法,结合温室墙体温度、墙体... 详细信息

为提高日光温室复合结构墙体热稳定层的温度并提升温室墙体材料的蓄热性能,该研究提出一种新型日光温室平板微热管阵列蓄热墙体(Micro Heat Pipe Array,MHPA),搭建了小型MHPA墙体温室试验台,采用对比试验的方法,结合温室墙体温度、墙体蓄放热量以及温室环境温度等评价参数,对比分析了典型日MHPA墙体的蓄放热特性及其改善温室热环境效果。结果表明,与普通温室相比,冬季典型晴天,放热时段(17:00至次日9:00)MHPA墙体内表面平均温度提高1.6~2.3℃,由室内向室外沿墙体厚度方向0~370 mm区域内MHPA墙体内部的平均温度提高2.7~4.0℃;MHPA温室的平均温室环境温度提升1.2~1.5℃,地表面平均温度提升0.6~1.0℃;MHPA墙体的日总蓄热量提高了8.93%~14.35%,日总放热量提高了2.24%~8.07%,且在夜间23:00至次日7:00 MHPA墙体的放热速率高于普通墙体的,平均提升11.53%。因此,MHPA墙体引入于日光温室墙体中可提升温室墙体材料的蓄放热性能,改善温室热环境。该结果可为日光温室平板微热管阵列蓄热墙体的应用提供参考。

关键词：温室墙体蓄热微热管阵列蓄放热性能试验研究