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Chinese Science Bulletin 2013年第7期58卷 621-628页

作者： dai yitang XU Kun XIE XiaoJun YAN Li WANG RuiXin LIN JinTong Beijing University of Posts and Telecommunications State Key Laboratory of Information Photonics and Optical CommunicationsP.O.Box 55(BUPT)

In this work,we analyze and demonstrate a novel photonic-assisted broadband and high-resolution radio frequency(RF) channelization scheme based on dual coherent optical frequency combs(OFCs),regular optical de-muxes,and polarization I/Q demodulators in theory and *** use of two coherent combs avoids precise optical alignment,and a numerical filter in digital signal processor(DSP) enables an ideal rectangular frequency response in each channel without any ultra-narrow optical ***,due to the use of polarization I/Q demodulation,ambiguous frequency estimate in direct detection can be avoided and the amplitude,phase mismatch in traditional I/Q demodulation can be *** experiment,we use two coherent OFCs with the free spectrum range(FSR) of about 40 GHz to demonstrate the channelization scheme with seven channels,500 MHz channel spacing and frequency coverage from 3.75 GHz to 7.25 *** input RF tones are accurately down-converted to an intermediate frequency(IF) with a maximum frequency error of 110 ***,crosstalk and spurious free dynamic range(SFDR) of the scheme are also discussed.

关键词：信道间隔解调器光频梳偏振相干 RF 射频光子

Large-scale coherent Ising machine based on optoelectronic parametric oscillator

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Light(Science & Applications) 2022年第12期11卷 2972-2981页

作者： Qizhuang Cen Hao Ding Tengfei Hao Shanhong Guan Zhiqiang Qin Jiaming Lyu Wei Li Ninghua Zhu Kun Xu yitang dai Ming Li State Key Laboratory on Integrated Optoelectronics Institute of SemiconductorsChinese Academy of SciencesBeijingChina School of Electronic Electrical and Communication EngineeringUniversity of Chinese Academy of SciencesBeijingChina Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijingChina State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and TelecommunicationsBeijingChina School of Optical-Electrical and Computer Engineering University of Shanghai for Science and TechnologyShanghaiChina Peng Cheng Laboratory ShenzhenChina

Ising machines based on analog systems have the potential to accelerate the solution of ubiquitous combinatorial optimization *** some artificial spins to support large-scale Ising machines have been reported,e.g.,superconducting qubits in quantum annealers and short optical pulses in coherent Ising machines,the spin stability is fragile due to the ultra-low equivalent temperature or optical phase *** this paper,we propose to use short microwave pulses generated from an optoelectronic parametric oscillator as the spins to implement a large-scale Ising machine with high *** proposed machine supports 25,600 spins and can operate continuously and stably for ***,the proposed Ising machine is highly compatible with high-speed electronic devices for programmability,paving a low-cost,accurate,and easy-to-implement way toward solving real-world optimization problems.

关键词： stability oscillator coherent

Simple Precise Time Signal Delivery over Fiber Link Scheme

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Simple Precise Time Signal Delivery over Fiber Link Scheme

第五届中国卫星导航学术年会

作者： yitang dai Zhongle Wu Tianpeng Ren Feifei Yin Kun Xu Jintong Lin Geshi Tang State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications Science and Technology on Aerospace Flight Dynamics Laboratory Beijing Aerospace Control Center

The capability of transferring time signal to remote locations with high stability and accuracy for synchronization is crucial for many important occasions,involving very long‐baseline interferometry,coherent radio telescope arrays,modern particle accelerator,and the Deep Space *** widely used satellite methods of time and frequency transfer are unable to preserve the stability delivered by modern timekeeping *** meet these high stability requirements,optical fiber link has been used to transfer frequency and time reference,which however still suffers from mechanical perturbation and temperature variation along the link and degrades the phase stability at the remote *** the past decade,researchers mainly focused on the frequency dissemination,and the transfer stability is now sufficient for most frequency ***,the time signal transfer stability is far below frequency reference,which is typically at the nanosecond accuracy *** propose and demonstrate a stable time signal delivery scheme over fiber link utilizing frequency stabilization *** the scheme,we utilizing the frequency reference to compensate the link‐length variation,and the total transfer delay is kept *** time signal is regenerated at the remote *** fiber link we used in this paper is 10‐km,and the long‐term fiber delay variation is more than 800 *** obtain a time deviation of 40 ps at 1‐s and falling to 2.3 ps at 1000‐s averaging time for time *** time delay resolution of scheme is 1 ps,and the compensation range is in direct proportion with the fiber *** proposed scheme shows a potential ability to precisely transfer time signal and frequency reference simultaneously,which is very suitable for long range time and frequency transfer.

关键词： Time and Frequency Delivery Fiber Link Time Deviation

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改进现行铁路工程定额的几点见解

铁路工程造价管理 2003年第6期18卷 30-31,38页

作者：戴怡堂广铁集团广州510600

围绕铁路跨越式发展的主题 ,铁路工程定额应以提高准确率、堵塞变更活口、降低工程造价为改进目标。此文阐述铁路工程概预算定额和费率应与验收标准、施工对象的环境条件、施工组织条件、安全要求及标底编制需要等方面相适应。

关键词：铁路工程工程定额准确率工程造价改进目标概预算定额验收标准施工组织条件

Seismic performance evaluation of water supply pipes installed in a full-scale RC frame structure based on a shaking table test

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Earthquake Engineering and Engineering Vibration 2024年第1期23卷 163-178页

作者： Wu Houli Guo Endong Wang Jingyi dai Xin dai Chenxi Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin 150080China Key Laboratory of Earthquake Disaster Mitigation Ministry of Emergency ManagementHarbin 150080China

As an important part of nonstructural components,the seismic response of indoor water supply pipes deserves much *** paper presents shaking table test research on water supply pipes installed in a full-scale reinforced concrete(RC)frame *** material pipes and different methods for penetrating the reinforced concrete floors are combined to evaluate the difference in seismic *** response spectra and pipe acceleration amplification factors based on test data are discussed and compared with code provisions.A seismic fragility study of displacement demand is conducted based on numerical *** acceleration response and displacement response of different combinations are *** results show that the combination of different pipe materials and different passing-through methods can cause obvious differences in the seismic response of indoor riser pipes.

关键词： water supply pipe different materials shaking table test amplification factor seismic fragility

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高分辨率任意可重构微波光子滤波器

红外与激光工程 2023年第10期52卷 149-157页

作者：王敬雯尹子恺尹飞飞戴一堂北京邮电大学信息光子学与光通信国家重点实验室北京100876

提出了一种能够实现任意滤波形状的高分辨率可重构微波光子滤波器方案。利用可编程光滤波器完成抽头系数的独立灵活配置,配合使用相干探测技术实现滤波器的正负抽头,从而可以完成滤波形状的任意可重构。研究表明一个大梳齿数量的平坦光... 详细信息

提出了一种能够实现任意滤波形状的高分辨率可重构微波光子滤波器方案。利用可编程光滤波器完成抽头系数的独立灵活配置,配合使用相干探测技术实现滤波器的正负抽头,从而可以完成滤波形状的任意可重构。研究表明一个大梳齿数量的平坦光频梳被作为光源可提高抽头数量,从而实现高分辨率的滤波器的重构。除此之外,通过预先引入色散,响应中的杂散也被有效地抑制。经仿真验证,该滤波器具有93 MHz的高分辨率,杂散抑制40 dB以上,创新性地构造了具有不同中心频率的低通、带通、高通、带阻滤波器,以及矩形、高斯形、sinc形等任意滤波形状,对于后续微波光子滤波器的研究起到了引导性作用。

关键词：微波光子学微波光子滤波器相干探测技术可重构高分辨率杂散干扰抑制

Near-field wideband beam training for ELAA with uniform circular array

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Science China(Information Sciences) 2024年第6期67卷 370-383页

作者： Yuhao CHEN Linglong dai Department of Electronic Engineering Tsinghua UniversityBeijing National Research Center for Information Science and Technology (BNRist)

Extremely large-scale antenna array(ELAA) at millimeter wave(mmWave) and Terahertz(THz)band has been considered a key technology for combating high attenuation in high-frequency bands in future6G communications. Uniform circular arrays(UCAs) have attracted much attention because of their ability to provide flat beamforming gain at all angles. To realize efficient beamforming, beam training is widely used to acquire channel state information. However, with a large antenna number, the beam training overhead in ELAA systems becomes overwhelming. Moreover, with a large bandwidth, the beam defocus effect severely degrades beam training accuracy. To address these issues, this paper proposes a frequency-dependent focusing(FDF)-based beam training scheme to realize effective beam training in near-field wideband ELAA systems with UCA. Specifically, we first analyze the FDF property of UCA, where signals at different subcarriers can simultaneously focus on different distances. Then, by exploiting the FDF property to search different distances using different subcarriers simultaneously, we design a hierarchical codebook and propose an FDFbased beam training scheme. To reveal the effectiveness of the proposed scheme, we compare its necessary beam training overhead with that of existing schemes. Finally, the simulation results demonstrate that the proposed scheme can achieve accurate beam training in near-field wideband UCA systems with a low beam training overhead.

关键词： extremely large-scale antenna array (ELAA) uniform circular array (UCA) near-field wideband beam training

Biohythane production from two-stage anaerobic digestion of food waste:A review

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Journal of Environmental Sciences 2024年第5期139卷 334-349页

作者： Xiaona An Ying Xu Xiaohu dai State Key Laboratory of Pollution Control and Resource Reuse School of Environmental Science and EngineeringTongji UniversityShanghai 200092China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China

The biotransformation of food waste(FW)to bioenergy has attracted considerable research attention as a means to address the energy crisis and waste disposal *** this end,a promising technique is two-stage anaerobic digestion(TSAD),in which the FW is transformed to biohythane,a gaseous mixture of biomethane and *** review summarises the main characteristics of FW and describes the basic principle of ***,the factors influencing the TSAD performance are identified,and an overview of the research status;economic aspects;and strategies such as pre-treatment,co-digestion,and regulation of microbial consortia to increase the biohythane yield from TSAD is ***,the challenges and future considerations associated with the treatment of FW by TSAD are *** paper can provide valuable reference for the improvement and widespread implementation of TSAD-based FW treatment.

关键词： Two-stage anaerobic digestion(TSAD) Food waste(FW) Methane production Hydrogen production

State of the art of lightweight aggregates used in lightweight refractories for working lining of high-temperature furnaces

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Journal of Iron and Steel Research International 2024年第6期31卷 1320-1343页

作者： Wei Zhang Wen-yong dai Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016LiaoningChina Research and Development Department AGC Plibrico(Dalian)Industries Inc.Dalian 116600LiaoningChina

Lightweight refractories for the working lining of high-temperature furnaces play an important role in the smelting of advanced steels and *** prepare lightweight refractories for the working lining of high-temperature furnaces,the synthesis of lightweight aggregates is the ***,the research on the synthesis of lightweight aggregates with high service temperature,low thermal conductivity,high strength,and good slag resistance has received widespread *** available literature on the synthesis of lightweight aggregates was summarized,including corundum,mullite,mullite-corundum,spinel,corundum-spinel,cordierite,cordierite-mullite,calcium hexaluminate,corundum-calcium hexaluminate,bauxite,magnesia,magnesia-based,and forsterite-based ***,the future development trend of lightweight aggregates was proposed.

关键词： Lightweight aggregate Lightweight refractory Working lining Apparent porosity Closed porosity Thermal conductivity Pore-forming approach

Impacts of external forcing and internal variability on the North Atlantic multidecadal variations since 1950

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Science China Earth Sciences 2024年第8期67卷 2699-2701页

作者： Wenjian HUA Aiguo dai Key Laboratory of Meteorological Disaster Ministry of Education/Collaborative Innovation Center on Forecast and Evaluation of Meteorological DisastersNanjing University of Information Science and TechnologyNanjing 210044China Department of Atmospheric and Environmental Sciences University at AlbanyState University of New YorkAlbany 12222USA

The physical formation mechanisms of the Atlantic Multidecadal Variability(AMV)in the context of global warming have been a key research topic(Vecchi et al.,2017).The conventional view is that the AMV is mainly driven by internal dynamics within the climate system,especially in the Atlantic Ocean(Zhang et al.,2019).However,some studies suggest that decadal to multidecadal variations in North Atlantic sea surface temperature(SST)since around 1950 are related to anthropogenic and natural aerosol emissions(Otter?et al.,2010;Booth et al.,2012;Hua et al.,2019).

关键词： Atlantic decadal forcing

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