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An Improved Calibration Method of Grating Projection Measurement System

Computers, Materials & Continua 2023年第5期75卷 3957-3970页

作者： Qiucheng Sun weiyu dai Mingyu Sun Zeming Ren Mingze Wang College of Computer Science and Technology Changchun Normal University130000ChangchunChina

In the traditional fringe projection profilometry system,the projector and the camera light center are both spatially virtual *** spatial position relationships specified in the model are not easy to obtain,leading to inaccurate system parameters and affectingmeasurement *** paper proposes a method for solving the system parameters of the fringe projection profilometry system,and the spatial position of the camera and projector can be adjusted in accordance with the obtained calibration *** steps are as follows:First,in accordance with the conversion relationship of the coordinate system in the calibration process,the calculation formula of the vertical distance from the camera light center to the reference plane and the calculation formula of the distance between the projector and the camera light center are given ***,according to the projector calibration principle,the position of the projector light axis perpendicular to the reference plane is gained by comparing the parallel relationship between the reference plane coordinate system and the projector coordinate system’s ***,in order to fulfill the position restriction that the line between the projector light center and the camera light center must be parallel to the reference plane,the camera’s spatial location is adjusted so that the vertical distance between it and the reference plane tends to that between the projector light center and the reference *** finally,the three-dimensional(3D)reconstruction of the target object can be finished using the phase height model’s system parameters once the aforementioned position limitations are put into *** results demonstrate that the method improves the measurement accuracy,and verifies that it is effective and available in 3D shape measurement.

关键词： 3D measurement calibration phase shift phase height model

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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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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

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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

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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

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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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Neighborhood predictors of short sleep duration and bedtime irregularity among children in the United States: results from the 2019-2020 National Surveyof Children's Health

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World Journal of Pediatrics 2024年第1期20卷 73-81页

作者： Ying dai Jianghong Liu School of Nursing University of Pennsylvania418 Curie Blvd.Room 426Claire M.Fagin HallPhiladelphiaPA19104-6096USA

Background Environmental factors may contribute to short sleep duration and irregular bedtime in *** factors and children's sleep duration and bedtime regularity remain a less investigated *** aim of this study was to investigate the national and state-level proportions of children with short sleep duration and irregular bedtime and their neighborhood *** A total of 67,598 children whose parents completed the National Survey of Children's Health in 2019-2020 were included in the ***-weighted Poisson regression was used to explore the neighborhood predictors of children's short sleep duration and irregular *** The prevalence of short sleep duration and irregular bedtime among children in the United States(US)was 34.6%[95%confidence interval(CI)=33.8%-35.4%]and 16.4%(95%CI=15.6%-17.2%)in 2019-2020,*** neighborhoods,supportive neighborhoods,and neighborhoods with amenities were found to be protective factors against children's short sleep duration,with risk ratios ranging between 0.92 and 0.94,P<*** with detracting elements were associated with an increased risk of short sleep duration[risk ratio(RR)=1.06,95%CI=1.00-1.12]and irregular bedtime(RR=1.15,95%CI=1.03-1.28).Child race/ethnicity moderated the relationship between neighborhood with amenities and short *** Insufficient sleep duration and irregular bedtime were highly prevalent among US children.A favorable neighborhood environment can decrease children's risk of short sleep duration and irregular *** the neighborhood environment has implications for children's sleep health,especially for children from minority racial/ethnic groups.

关键词： Child National Survey of Children's Health Neighborhood.Sleep Social determinants of health

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Prevalence and risk evaluation of cardiovascular disease in the newly diagnosed prostate cancer population in China:A nationwide,multi-center,population-based cross-sectional study

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Chinese Medical Journal 2024年第11期137卷 1324-1331页

作者： weiyu Zhang Huixin Liu Ming Liu Shi Ying Renbin Yuan Hao Zeng Zhenting Zhang Sujun Han Zhannan Si Bin Hu Simeng Wen Pengcheng Xu Weimin Yu Hui Chen Liang Wang Zhitao Lin Tao dai Yunzhi Lin Tao Xu Department of Urology Peking University People’s HospitalBeijing 100044China Department of Clinical Epidemiology and Biostatistics Peking University People’s HospitalBeijing 100044China Department of Urology Beijing HospitalNational Center of GerontologyBeijing 100005China Institute of Geriatric Medicine Chinese Academy of Medical SciencesBeijing 100005China Department of Urology Wuhan Union HospitalHuazhong University of Science&TechnologyWuhanHubei 430022China Department of Urology The Third People’s Hospital of ChengduChengduSichuan 610014China Department of Urology West China Hospital of Sichuan UniversityChengduSichuan 610041China Department of Urologic Oncology Tianjin Medical University Cancer Institute&HospitalTianjin 300060China Department of Urology Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100021China National Cancer Center Beijing 100021China National Clinical Research Center for Cancer Beijing 100021China Department of Urology Liaoning Cancer HospitalShenyangLiaoning 110801China Department of Urology The Second Hospital of Tianjin Medical UniversityTianjin 300141China Tianjin Institute of Urology Tianjin Medical UniversityTianjin 300141China Department of Urology Lu’an Affiliated Hospital of Anhui Medical UniversityLu’anAnhui 237322China Department of Urology Renmin Hospital of Wuhan UniversityWuhanHubei 430060China Department of Urology Harbin Medical University Affiliated Cancer HospitalHarbinHeilongjiang 150081China Department of Urology The Second Hospital of Dalian Medical UniversityDalianLiaoning 116023China Department of Urology Surgery Fujian Cancer HospitalFuzhouFujian 350014China Department of Urology Surgery Hunan Cancer HospitalChangshaHunan 410031China Department of Urology Surgery The First Affiliated Hospital of Fujian Medical UniversityFuzhouFujian 350004China

Background:Cardiovascular disease(CVD)has emerged as the leading cause of death from prostate cancer(PCa)in recent decades,bringing a great disease burden *** with preexisting CVD have an increased risk for major adverse cardiovascular events when treated with androgen deprivation therapy(ADT).The present study aimed to explore the prevalence and risk evaluation of CVD among people with newly diagnosed PCa in ***:Clinical data of newly diagnosed PCa patients were retrospectively collected from 34 centers in China from 2010 to 2022 through convenience *** was defined as myocardial infarction,arrhythmia,heart failure,stroke,ischemic heart disease,and *** risk was estimated by calculating Framingham risk scores(FRS).Patients were accordingly divided into low-,medium-,and high-risk groups.χ2 or Fisher’s exact test was used for comparison of categorical ***:A total of 4253 patients were enrolled in the present study.A total of 27.0%(1147/4253)of patients had comorbid PCa and CVD,and 7.2%(307/4253)had two or more *** enrolled population was distributed in six regions of China,and approximately 71.0%(3019/4253)of patients lived in urban *** imaging and pathological evaluation,most PCa patients were diagnosed at an advanced stage,with 20.5%(871/4253)locally progressing and 20.5%(871/4253)showing *** of them initiated prostatectomy(46.6%,1983/4253)or regimens involving ADT therapy(45.7%,1944/4253)for prostate *** the present PCa cohort,43.1%(1832/4253)of patients had hypertension,and half of them had poorly controlled blood *** FRS stratification,as expected,a higher risk of CVD was related to aging and metabolic ***,we also found that patients with treatment involving ADT presented an originally higher risk of CVD than those without *** was in accordance with clinical practice,i.e.,aged patients or patients at advanced oncological stages were inclined to accept sys

关键词： Prostate cancer Castration Cardiovascular disease Prevalence Cardiovascular risk

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Amorphous hybrid tungsten oxide–nickel hydroxide nanosheets used as a highly efficient electrocatalyst for hydrogen evolution reaction

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Nano Research 2024年第4期17卷 2499-2508页

作者： Chao Lyu Chenghai dai Yiwei Tan State Key Laboratory of Materials-Oriented Chemical Engineering School of Chemistry and Chemical EngineeringNanjing Tech UniversityNanjing 211816China

There are more challenges for alkaline hydrogen evolution reaction(HER)via simultaneously expediting the electron-coupled water dissociation process(Volmer step)and the following electrochemical H_(2) desorption(Heyrovsky step).Hybrid amorphous electrocatalysts are highly desirable for efficient hydrogen evolution from water-alkali electrolyzers due to the bifunctionality for the different elementary steps of HER and optimal interactions with water molecules and the reactive hydrogen intermediates(Had).Herein,the synthesis of amorphous hybrid ultrathin(tungsten oxide/nickel hydroxide)hydrate(a-[WO_(3)/Ni(OH)_(2)]·0.2H_(2)O)nanosheets on nickel foam(NF)for efficient alkaline HER is *** structural and composition features of a-[WO_(3)/Ni(OH)_(2)]·0.2H_(2)O are characterized in *** resulting a-[WO_(3)/Ni(OH)_(2)]·0.2H_(2)O/NF electrocatalyst with the synergistic effect of both hybrid components for the HER elementary steps shows greatly improved the activity and durability for the HER with a low overpotential of-41 and-163 mV at-10 and-500 mA·cm^(-2),respectively,a Tafel slope as low as-72.9 mV·dec^(-1),and long-term stability of continuous electrolysis for at least 150 h accompanying by inappreciable overpotential change in 1 M *** the hybrid a-[WO_(3)/Ni(OH)_(2)]·0.2H_(2)O,Ni(OH)_(2) and WO_(3) moieties are separately responsible for accelerating dissociative adsorption of water and weakening Had adsorption strength,which is beneficial to the improvement of the alkaline HER activity.

关键词： amorphous nanomaterial bimetallic electrocatalyst tungsten oxide ultrathin nanosheet hydrogen evolution reaction

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A novel topology with controllable wideband baseband impedance for power amplifiers

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Frontiers of Information Technology & Electronic Engineering 2024年第2期25卷 308-315页

作者： Yao YAO Zhijiang dai Mingyu LI School of Intelligent Technology and Engineering Chongqing University of Science and TechnologyChongqing400065China School of Microelectronics and Communication Engineering Chongqing UniversityChongqing400065China

This paper presents a novel topology to control the baseband impedance of a power amplifier(PA)to avoid performance deterioration in concurrent dual-band *** topology can avoid pure resonance of capacitors and inductors LC,which leads to a high impedance at some frequency ***,it can be applied to transmitters that are excited by broadband *** particular,by adjusting the circuit parameters and increasing stages,the impedance of the key frequency bands can be flexibly controlled.A PA is designed to support this design *** saturated output power is around 46.7 dBm,and the drain efficiency is>68.2%(1.8-2.3 GHz).Under concurrent two-tone excitation,the drain efficiency reaches around 40%even under 5.5 dB back-off power with the tone spacing from 10 MHz to 500 *** results demonstrate that the proposed topology is capable of controlling wideband baseband impedance.

关键词： Baseband impedance Concurrent dual-band Power amplifier

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