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Ultralow-phase-noise and broadband frequency-hopping coupled optoelectronic oscillator under quiet point operation

Photonics Research 2024年第08期12卷 1785-1793页

作者： HUI LIU MINGYANG GUO TIAN ZHANG jian DAI KUN xu State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications School of Electronic Engineering Beijing University of Posts and Telecommunications

Advancements in microwave photonics have yielded novel approaches for generating high-purity microwave sources. Among these, optoelectronic oscillators（OEOs） and coupled optoelectronic oscillators（COEOs） have demonstrated the capability to generate frequency-independent microwaves with exceptionally low phase ***, the tunability of the oscillators is rather limited due to the necessity for narrowband electronic bandpass filters, presenting challenges in achieving both wide and rapid tuning capabilities. Here, we present a COEO featuring ultralow phase noise, flexible tuning capability, and high robustness. This is achieved through a quiet point（QP）-operated harmonic mode-locked fiber laser, which effectively mitigates optical amplifier noise and supermode competition, thus significantly diminishing the necessity for ultra-narrow electronic filters. Due to the liberated tuning ability, we present an oscillator that can be tuned from 2 GHz to 18 GHz, with phase noise as low as-140 d Bc/Hz at 10 k Hz under the QP operation. We then illustrate the practical application of the proposed oscillator in generating frequency-hopping signals with consistent spurious modes less than-85 d Bc,absolute phase noise below-135 d Bc/Hz at 10 k Hz, hopping resolution of 1.25 MHz, and fractional frequency stability below 6.1 × 10-12at 1 s averaging time when locked to a reference. The presented COEO structure emerges as a compelling solution for agile and low-noise microwave sources in advanced wireless communication and radar systems.

关键词： Bandpass filters Beam splitters Microwave photonics Mode-locked fiber lasers Optical amplifiers Phase noise

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Droplet morphology analysis of drop-on-demand inkjet printing

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China Foundry 2024年第1期21卷 20-28页

作者： Hu-xiang Xia Takechi Kensuke Tajima Shin Kawamura Yoshiumi qing-yan xu Key Laboratory for Advanced Materials Processing Technology(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Toyota Central R&D Labs. Inc.41-1 Yokomichi NagakuteAichi 480-1192Japan Frontier Research Center Toyota Motor Corporation1 Toyota-ChoToyotaAichi 471-8572Japan

As an accurate 2D/3D fabrication tool,inkjet printing technology has great potential in preparation of micro electronic *** morphology of droplets produced by the inkjet printer has a great impact on the accuracy of *** this study,the drop-on-demand(DoD)inkjet simulation model was established,and the accuracy of the simulation model was verified by corresponding *** simulation result shows that the velocity of the droplet front and tail,as well as the time to disconnect from the nozzle is mainly affected by density(ρ),viscosity(μ)and surface tension(σ)of *** the liquid filament is about to disconnect from the nozzle,the filament length and filament front velocity are found to have a linear correlation withσ/ρμand ln(ρ/(μσ1/2)).

关键词： microdevice fabrication inkjet printing droplet morphology modeling and simulation

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Progress of vegetation modelling and future research prospects

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Science China Earth Sciences 2024年第9期67卷 2718-2738页

作者： Siqi LI xu ZHANG Zhengyao LU jian NI jianhua LU State Key Laboratory of Tibetan Plateau Earth System Resources and Environment(TPESRE)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China British Antarctic Survey Cambridge CB30ETUnited Kingdom Department of Physical Geography and Ecosystem Science Lund UniversityLund 22362Sweden College of Life Sciences Zhejiang Normal UniversityJinhua 321004China School of Atmospheric Sciences Sun Yat-sen University and Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China

Terrestrial vegetation is a crucial component of the Earth system,and its changes not only represent one of the most distinct aspects of climate change but also exert significant feedback within the climate system by exchanging energy,moisture,and carbon *** quantitatively and mechanistically study climate-vegetation feedback,numerical vegetation models have been developed on the theory of ecophysiological constraints on plant functional *** models eventually can simulate vegetation distribution and succession across different spatial and temporal scales,and associated terrestrial carbon cycle processes by categorizing vegetation into biomes according different plant functional types and their associated environmental *** we review the developing history of vegetation models and provide recent advances and future *** 21st century,static vegetation models,as developed statistical models,can only simulate equilibrated characteristics of vegetation *** last several decades,Dynamic Global Vegetation Models(DGVMs)have been developed to simulate instantaneous responses of vegetation to climate change and associated dynamics,and can be coupled with Earth system models to investigate interactions among atmosphere,ocean,and *** are also widely applied to investigate the dynamics accounting for changes in the geographic distribution patterns of land surface vegetation at different spatial and temporal scales and to assess the impacts of terrestrial carbon and water fluxes and land use *** suggest that future vegetation modeling could integrate with machine learning,and explore vegetation transient response and feedback as well as impacts of process hierarchies and human activities on climate and ecosystem.

关键词： Vegetation models DGVMs Ecosystems Plant functional types Plant functional traits

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Charge-asymmetry Fe_(1)Cu single-atom alloy catalyst for efficient oxygen reduction reaction

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Nano Research 2024年第6期17卷 4702-4710页

作者： xudong Niu jian Wei Dongyao xu Jiajing Pei Rui Sui School of Chemical&Environmental Engineering China University of Mining and TechnologyBeijing 100083China Institute of Water Ecology and Environment Chinese Research Academy of Environmental SciencesBeijing 100083China Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Engineering Research Center of Advanced Rare Earth Materials Department of ChemistryTsinghua UniversityBeijing 100084China

The development of high-efficient and low-cost oxygen reduction reaction(ORR)electrocatalysts is crucial for the practical applications of metal-air *** promising way is to develop Fe single-atom ***,the single active center and inherent electronic structure of Fe single-atom catalysts lead to the undesirable adsorption of multiple ORR ***,a charge-asymmetry single-atom alloy(SAA)catalyst with Fe-Cu dual sites supported on nitrogen-doped carbon nanosheet(Fe_(1)Cu SAA/NC)was *** characterizations manifest the existence of electron interaction between Fe and Cu in Fe_(1)Cu SAA/NC,which facilitates the adsorption of ORR intermediate for fast ***,the charge-asymmetry Fe_(1)Cu SAA/NC exhibits much faster ORR kinetics with a half-wave potential of 0.917 V *** hydrogen electrode(RHE),outperforming its counterparts in the ***,Fe_(1)Cu SAA/NC still maintains a high half-wave potential with only a drop of 5 mV after 5000 cycles,indicating excellent *** work provides a new strategy to design highly active and non-noble metal ORR electrocatalysts,which hold great potential for various catalytic applications.

关键词： Fe_(1)Cu single-atom alloy(SAA) electrocatalysis oxygen reduction reaction charge-asymmetry

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Biomimetic soft robotic wrist with 3-DOF motion and stiffness tunability based on ring-reinforced pneumatic actuators and a particle jamming joint

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Science China(Technological Sciences) 2024年第3期67卷 774-790页

作者： HU TeTe LU Xinjiang YI jian WANG YuHui xu Du State Key Laboratory of Precision Manufacturing for Extreme Service Performance School of Mechanical and Electrical EngineeringCentral South UniversityChangsha 410083China

The human wrist, a complex articulation of skeletal muscles and two-carpal rows, substantially contributes to improvements in maneuverability by agilely performing three-degree-of-freedom(3-DOF) orienting tasks and regulating stiffness according to variations in interaction forces. However, few soft robotic wrists simultaneously demonstrate dexterous 3-DOF motion and variable stiffness;in addition, they do not fully consider a soft-rigid hybrid structure of integrated muscles and two carpal *** this study, we developed a soft-rigid hybrid structure to design a biomimetic soft robotic wrist(BSRW) that is capable of rotating in the x and y directions, twisting around the z-axis, and possessing stiffness-tunable capacity. To actuate the BSRW, a lightweight soft-ring-reinforced bellows-type pneumatic actuator(SRBPA) with large axial, linear deformation(η_(lcmax)=70.6%,η_(lemax)=54.3%) and small radial expansion(η_(demax)=3.7%) is designed to mimic the motion of skeletal muscles. To represent the function of two-carpal rows, a compact particle-jamming joint(PJJ) that combines particles with a membrane-covered ballsocket mechanism is developed to achieve various 3-DOF motions and high axial load-carrying capacity(>60 N). By varying the jamming pressure, the stiffness of the PJJ can be adjusted. Finally, a centrally positioned PJJ and six independently actuated SRBPAs, which are in an inclined and antagonistic arrangement, are sandwiched between two rigid plates to form a flexible,stable, and compact BSRW. Such a structure enables the BSRW to have a dexterous 3-DOF motion, high load-carrying ability,and stiffness tunability. Experimental analysis verify 3-DOF motion of BSRW, producing force of 29.6 N and 36 N and torque of2.2 Nm in corresponding rotations. Moreover, the range of rotational angle and stiffness-tuning properties of BSRW are studied by applying jamming pressure to the PJJ. Finally, a system combining a BSRW and a soft enclosing gripper is proposed to demo

关键词： pneumatic soft actuators particle jamming robotic wrist soft robotics stiffness-tunable

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Ambarzumyan's Theorem for the Dirac Operator on Equilateral Tree Graphs

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 568-576页

作者： Dong-Jie WU Xin-jian xu Chuan-Fu YANG Department of Mathematics School of Mathematics and StatisticsNanjing University of Science and TechnologyNanjing 210094China

The classical Ambarzumyan’s theorem states that if the Neumann eigenvalues of the Sturm-Liouville operator-d^(2)/dx^(2)+q with an integrable real-valued potential q on[0,π] are {n^(2):n≥0},then q=0 for almost all x∈[0,π].In this work,the classical Ambarzumyan’s theorem is extended to the Dirac operator on equilateral tree *** prove that if the spectrum of the Dirac operator on graphs coincides with the unperturbed case,then the potential is identically zero.

关键词： dirac operator quantum graph Ambarzumyan’s theorem inverse spectral problem

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COVID-19 pandemic amplified mortality rates among adolescents with bipolar disorder through family-related factors

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World Journal of Clinical Cases 2024年第11期12卷 1929-1935页

作者： Zhuo-Fan Ye Yi-Han Hong jian-Lin Yang Meng-qing Tan Ju-Min Xie Zu-Cai xu Department of Neurology The Affiliated Hospital of Zunyi Medical UniversityZunyi 563000Guizhou ProvinceChina Hubei Key Laboratory of Renal Disease Occurrence and Intervention Medical SchoolHubei Polytechnic UniversityHuangshi 435003Hubei ProvinceChina Psychological Children's Ward Mental Health Center of HuangshiHuangshi 435111Hubei ProvinceChina The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine Zunyi Medical UniversityZunyi 563000Guizhou ProvinceChina

BACKGROUND Recently,a growing number of adolescents have been afflicted with mental disorders,with annual morbidity rates on the *** trend has been exacerbated by the global coronavirus disease 2019(COVID-19)pandemic,leading to a surge in suicide and self-harm rates among this *** To investigate the impact of the COVID-19 pandemic on adolescent bipolar disorder(BD),along with the underlying factors contributing to heightened rates of suicide and self-harm among *** A comprehensive statistical analysis was conducted utilizing clinical interviews and self-reports obtained from patients or their *** criteria for BDs were based on the Diagnostic and statistical manual of mental disorders,international classification of diseases-11,and the National institute of mental health research domain *** analyses were performed using SPSS 26.0 software,with significance set at P<*** A cohort of 171 adolescents diagnosed with BD between January 1,2018,and December 31,2022,was included in the *** gender distribution was 2.8:1(female to male),with ages ranging from 11 to 18 years *** factors contributing to adolescent BDs included familial influences,academic stress,genetic predisposition and exposure to school-related ***,a significant increase in suicide attempts and self-harm incidents was observed among adolescents with BD during the COVID-19 *** analysis indicated that the pandemic exacerbated familial discord and heightened academic stress,thereby amplifying the prevalence of suicidal behavior and self-harm among *** The COVID-19 pandemic has exacerbated familial tensions and intensified the incidence of suicide and self-harm among adolescents diagnosed with *** study underscores the urgent need for societal,familial and educational support systems to prioritize the well-being of adolescents and offers valuable insights and guidelines

关键词： Adolescents Bipolar disorder COVID-19 Suicide Self-harm

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Clinical efficacy of Gamma Knife® combined with transarterial chemoembolization and immunotherapy in the treatment of primary liver cancer

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World Journal of Gastrointestinal Surgery 2024年第6期16卷 1601-1608页

作者： Guo-Feng Wang Chang-Xin Shu Xiao-Dong Cai Hong-Bo Wang jian-Hong xu Yu-qing Jia Department of General Surgery Yangzhou Friendship Hospital Affiliated to Medical College of Yangzhou UniversityYangzhou 225000Jiangsu ProvinceChina

BACKGROUND This study was designed to investigate the clinical efficacy and safety of Gamma Knife®combined with transarterial chemoembolization(TACE)and immunotherapy in the treatment of primary liver *** To investigate the clinical efficacy and safety of Gamma Knife®combined with TACE and immune-targeted therapy in the treatment of primary liver *** Clinical data from 51 patients with primary liver cancer admitted to our hospital between May 2018 and October 2022 were retrospectively *** patients underwent Gamma Knife®treatment combined with TACE and *** clinical efficacy,changes in liver function,overall survival(OS),and progression-free survival(PFS)of patients with different treatment responses were evaluated,and adverse reactions were *** The last follow-up for this study was conducted on October 31,*** evaluation of the 51 patients with primary liver cancer revealed a partial response(PR)in 27 patients,accounting for 52.94%(27/51);stable disease(SD)in 16 patients,accounting for 31.37%(16/51);and progressive disease(PD)in 8 patients,accounting for 15.69%(8/51).The objective response rate was 52.94%,and the disease control rate was 84.31%.Alanine aminotransferase,aspartate aminotransferase,lactate dehydrogenase,and alpha-fetoprotein isoform levels decreased after treatment compared with pretreatment(all P=0.000).The median OS was 26 months[95%confidence interval(95%CI):19.946-32.054]in the PR group and 19 months(95%CI:14.156-23.125)in the SD+PD group,with a statistically significant difference(P=0.015).The median PFS was 20 months(95%CI:18.441-34.559)in the PR group and 12 months(95%CI:8.745-13.425)in the SD+PD group,with a statistically significant difference(P=0.002).Common adverse reactions during treatment included nausea and vomiting(39.22%),thrombocytopenia(27.45%),and leukopenia(25.49%),with no treatment-related deaths *** Gamma Knife®combined with TACE and immune-targeted th

关键词： Gamma Knife® Transarterial chemoembolization Immunotherapy Primary liver cancer Liver function

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High patatin like phospholipase domain containing 8 expression as a biomarker for poor prognosis of colorectal cancer

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World Journal of Gastrointestinal Oncology 2024年第3期16卷 787-797页

作者： Peng-Yang Zhou De-Xiang Zhu Yi-Jiao Chen qing-Yang Feng Yi-Hao Mao Ao-Bo Zhuang jian-Min xu Department of General Surgery Zhongshan Hospital Fudan UniversityShanghai 200032China

BACKGROUND Patatin like phospholipase domain containing 8(PNPLA8)has been shown to play a significant role in various cancer *** studies have focused on its roles as an antioxidant and in lipid ***,the role of PNPLA8 in colorectal cancer(CRC)progression is *** To explore the prognostic effects of PNPLA8 expression in *** A retrospective cohort containing 751 consecutive CRC patients was ***8 expression in tumor samples was evaluated by immunohistochemistry staining and semi-quantitated with immunoreactive *** patients were divided into high and low PNPLA8 expression groups based on the cut-off va-lues,which were calculated by X-tile *** prognostic value of PNPLA8 was identified using univariate and multivariate Cox regression *** over-all survival(OS)rates of CRC patients in the study cohort were compared with Kaplan-Meier analysis and Log-rank *** PNPLA8 expression was significantly associated with distant metastases in our cohort(P=0.048).CRC patients with high PNPLA8 expression indicated poor OS(median OS=35.3,P=0.005).CRC patients with a higher PNPLA8 expression at either stage I and II or stage III and IV had statistically significant shorter *** patients with left-sided colon and rectal cancer,the survival curves of two PN-PLA8-expression groups showed statistically significant *** analysis also confirmed that high PNPLA8 expression was an independent prog-nostic factor for overall survival(hazard ratio HR=1.328,95%CI:1.016-1.734,P=0.038).

关键词： Biomarker Colorectal cancer Expression level Overall survival Patatin like phospholipase domain containing 8 Prognosis

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Effects of hormone replacement therapy on mood and sleep quality in menopausal women

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World Journal of Psychiatry 2024年第7期14卷 1087-1094页

作者： qing Liu Zhen Huang Ping xu Department of Gynecology Ganzhou Women’s and Children’s HospitalGanzhou 341000Jiangxi ProvinceChina

BACKGROUND Hormone replacement therapy is an effective treatment strategy for the management of symptoms in naturally menopausal ***,some patients report experiencing adverse *** To analyze the effects of hormone replacement therapy in menopausal female *** A total of 152 menopausal female patients admitted to the Gynecology Department of the Ganzhou Maternal and Child Health Hospital between January 2021 and December 2023 were divided into the observation group(n=76,conventional treatment+hormone replacement therapy)and the control group(n=76,conventional treatment only)via random *** improvement observed in the following items were compared between the groups:Kupperman menopausal index(KMI),emotional state[The Positive and Negative Affect Scale(PANAS)],sleep quality[Self-Rating Scale of Sleep(SRSS)],treatment effectiveness,and treatment *** The modified KMI and SRSS scores of the observation group were lower than those of the control group after three rounds of *** improvement in the PANAS score observed in the observation group was greater than that observed in the control group(P<0.05).The total treatment effectivity rate in the observation group was higher than that in the control group(86.84%vs 96.05%,χ2=4.121,P=0.042).The incidence rate of adverse reactions in the two groups was comparable(6.58%vs 9.21%,χ2=0.361,P=0.547).CONCLUSION Hormone replacement therapy effectively improved the clinical symptoms,actively channeled negative emotions,and improved the quality of sleep in menopausal patients,indicating its effectiveness and safety.

关键词： Hormone replacement therapy Menopause Women Mood states Sleep quality Sex hormones

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