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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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Recent progress in single crystal perovskite X-ray detectors

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Science China(Information Sciences) 2024年第3期67卷 5-19页

作者： Xiao LIU Jun REN Yu-Ang CHEN Xiangshun GENG Dan XIE Tian-Ling REN School of Integrated Circuits Tsinghua University Beijing national Research center for Information Science and Technology (BNRist)

Perovskites have attracted extensive attention as radiation detection material due to their long carrier diffusion length and lifetime, high absorption coefficient, and flexible manufacturing process. Compared with polycrystalline structures, single crystal perovskites improve the performance of optoelectronic devices due to their low defect state density, better photoelectric characteristics, and chemical ***, we review the recent progress of single crystal perovskite X-ray detectors. First, we briefly introduced the basic concepts, detection mechanisms, figure of merits of perovskite X-ray detectors, and the preparation methods of single crystal perovskites. Then, we summarized the significant advancements in single crystal perovskite X-ray detectors in recent times. Finally, we discussed the critical challenges and some practicable solutions for developing high-performance X-ray detectors.

关键词： single crystal perovskites carrier transport radiation detection X-ray detectors X-ray imaging

Effectiveness and safety of combined nimotuzumab and S-1 chemotherapy with concurrent radiotherapy for locally advanced esophageal cancer in malnourished and elderly patients:A prospective phaseⅡstudy

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Chinese Journal of Cancer Research 2024年第3期36卷 270-281页

作者： Guojie Feng Jiao Li Nuo Yu Ziyu Zheng Xiongtao Yang Lei Deng Tao Zhang Wenqing Wang Wenyang Liu Jianyang Wang Qinfu Feng Jima Lyu Zefen Xiao Zongmei Zhou Nan Bi Jianjun Qin Xin Wang Department of Radiation Oncology National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100021China Department of Thoracic Surgery National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100021China

Objective:Definitive chemoradiotherapy(dCRT)is the standard treatment for unresectable locally advanced esophageal ***,this treatment is associated with substantial toxicity,and most malnourished or elderly patients are unable to complete this ***,there is a need for a more suitable radiotherapy combination regimen for this *** study was aimed to evaluate the efficacy and safety of a combination regimen comprising chemotherapy with nimotuzumab and S-1 and concurrent radiotherapy for patients with fragile locally advanced esophageal cancer with a high Nutritional Risk Screening 2002(NRS-2002)***:Eligible patients with unresectable esophageal carcinoma who had an NRS-2002 score of 2 or higher were *** were treated with S-1 and nimotuzumab with concurrent radiotherapy,followed by surgery or definitive *** primary endpoint was the locoregional control(LRC)***:A total of 55 patients who met the study criteria were *** completion of treatment,surgery was performed in 15 patients and radiotherapy was continued in 40 *** median follow-up period was 33.3[95%confidence interval(95%CI,31.4−35.1)]*** LRC rate was 77.2%(95%CI,66.6%−89.4%)at 1 year in the entire *** overall survival(OS)rate and event-free survival(EFS)rate were 57.5%and 51.5%at 3 years,*** was associated with better LRC[hazard ratio(HR)=0.16;95%CI,0.04−0.70;P=0.015],OS(HR=0.19;95%CI,0.04−0.80;P=0.024),and EFS(HR=0.25;95%CI,0.08−0.75;P=0.013).Most adverse events were of grade 1 or 2,and no severe adverse events ***:For malnourished or elderly patients with locally advanced esophageal cancer,radiotherapy combined with nimotuzumab and S-1 is effective and has a good safety profile.

关键词： Esophageal carcinoma squamous cell carcinoma nutritional risk score nimotuzumab S-1 definitive chemoradiotherapy

Spatial search weighting information contained in cell velocity distribution

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Chinese Physics B 2024年第2期33卷 522-528页

作者：马一凯李娜陈唯 State Key Laboratory of Surface Physics and Department of Physics Fudan UniversityShanghai 200438China China national center for Bioinformation Beijing 100101China national Genomics Data center Beijing Institute of GenomicsChinese Academy of SciencesBeijing 100101China

Cell migration plays a significant role in physiological and pathological *** the characteristics of cell movement is crucial for comprehending biological processes such as cell functionality,cell migration,and cell–cell *** of the fundamental characteristics of cell movement is the specific distribution of cell speed,containing valuable information that still requires comprehensive *** article investigates the distribution of mean velocities along cell trajectories,with a focus on optimizing the efficiency of cell food search in the context of the entire *** confirm that the specific velocity distribution in the experiments corresponds to an optimal search efficiency when spatial weighting is *** simulation results indicate that the distribution of average velocity does not align with the optimal search efficiency when employing average spatial ***,when considering the distribution of central spatial weighting,the specific velocity distribution in the experiment is shown to correspond to the optimal search *** simulations reveal that for any given distribution of average velocity,a specific central spatial weighting can be identified among the possible central spatial weighting that aligns with the optimal search ***,our work presents a method for determining the spatial weights embedded in the velocity distribution of cell *** results have provided new avenues for further investigation of significant topics,such as relationship between cell behavior and environmental conditions throughout their evolutionary history,and how cells achieve collective cooperation through cell-cell communication.

关键词： cell migration foraging efficiency random walk spatial search weight

Characteristics of cell motility during cell collision

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Chinese Physics B 2024年第2期33卷 72-77页

Quantitative examination of cellular motion and intercellullar interactions possesses substantial relevance for both biology and ***,the effects of intercellular interactions during cellular locomotion remain under-explored in experimental *** such,this study seeks to bridge this research gap,adopting Dictyostelium discoideum(Dicty)cells as a paradigm to investigate variations in cellular motion during reciprocal *** aim to attain a comprehensive understanding of how cell interactions influence cell *** observing and processing the motion trajectories of colliding cells under diverse chemical environments,we calculated the diffusion coefficient(D)and the persistence time(τ),using mean square *** analysis of the relationship dynamics between D andτprior to the collisions reveals intricate and non-monotonic alterations in cell movements during *** quantitatively scrutinizing theτtrend,we were able to categorize the cellular responses to interactions under different ***,we ascertained that the effect of cell interactions during collisions in Dicty cells emulates a classical sigmoid *** discovery suggests that cellular responses might comply with a pattern akin to the Weber–Fechner law.

关键词： cell migration random walk cell-cell interaction

Topological and superconducting properties of monolayered CoN and CoP:A first-principles comparative study

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 98-108页

作者： Jiaqing Gao Zhenyu Zhang Ping Cui International center for Quantum Design of Functional Materials(ICQD) Hefei National Research Center for Physical Sciences at Microscale(HFNL)University of Science and Technology of ChinaHefei 230026China Hefei national Laboratory University of Science and Technology of ChinaHefei 230088China

Two-dimensional systems that simultaneously harbor superconductivity and nontrivial band topology may serve as appealing platforms for realizing topological superconductivity with promising applications in fault-tolerant quantum ***,based on first-principles calculations,we show that monolayered Co N and Co P with the isovalent Fe Se-like structure are stable in freestanding form,even though their known bulk phases have no resemblance to *** two systems are further revealed to display intrinsic band inversions due to crystal field splitting,and such orderings are preserved with the inclusion of spin-orbit coupling(SOC),which otherwise is able to open a curved band gap,yielding a non-zero Z2 topological invariant in each *** a mechanism of topologicalization is distinctly contrasted with that identified recently for the closely related monolayers of CoX(X=As,Sb,Bi),where the SOC plays an indispensable role in causing a nontrivial band ***,we demonstrate that,by applying equi-biaxial tensile strain,the electron-phonon coupling strength in monolayered CoN can be significantly enhanced,yielding a superconducting transition temperature(Tc)up to 7-12 K for the Coulomb pseudopotential ofμ*=0.2-0.1,while the CoP monolayer shows very low Tc even under pronounced *** different superconducting behaviors can be attributed to different variations in lattice softening and electronic density of states around the Fermi level upon *** central findings enrich the understanding of different mechanisms of band inversions and topologicalization and offer platforms for achieving the coexistence of superconductivity and nontrivial band topology based on two-dimensional systems.

关键词： topological yielding otherwise

Signature of Superconductivity in Pressurized La_(4)Ni_(3)O_(10)

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Chinese Physics Letters 2024年第1期41卷 77-84页

作者：李庆张英杰项浙宁张宇航祝熙宇闻海虎 national Laboratory of Solid State Microstructures and Department of Physics Center for Superconducting Physics and MaterialsCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China

The discovery of high-temperature superconductivity near 80K in bilayer nickelate La_(3)Ni_(2)O_(7)under high pressures has renewed the exploration of superconducting nickelate in bulk *** extension of superconductivity in other nickelates in a broader family is also ***,we report the experimental observation of superconducting signature in trilayer nickelate La_(4)Ni_(3)O_(10)under high *** using a modified solgel method and post-annealing treatment under high oxygen pressure,we successfully obtained polycrystalline La_(4)Ni_(3)O_(10)samples with different transport behaviors at ambient *** we performed high-pressure electrical resistance measurements on these samples in a diamond-anvil-cell ***,the signature of possible superconducting transition with a maximum transition temperature(T_(c))of about 20K under high pressures is observed,as evidenced by a clear drop of resistance and the suppression of resistance drops under magnetic *** the resistance drop is sample-dependent and relatively small,it appears in all of our measured *** argue that the observed superconducting signal is most likely to originate from the main phase of La_(4)Ni_(3)O_(10).Our findings will motivate the exploration of superconductivity in a broader family of nickelates and shed light on the understanding of the underlying mechanisms of high-T_(c) superconductivity in nickelates.

关键词： materials superconductivity signature

The prognostic value of collateral circulation in coronary chronic total occlusion underwent percutaneous coronary intervention

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Journal of Geriatric Cardiology 2024年第2期21卷 232-241页

作者： Xiao-Ying HU Wei-Xian YANG Chang-Dong GUAN Li-Hua XIE Ke-Fei DOU Yong-Jian WU Jin-Qing YUAN Jie QIAN Yue-Jin YANG Shu-Bin QIAO Lei SONG Department of Cardiology Fuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina national Clinical Research center for Cardiovascular Diseases BeijingChina Catheterization Laboratories Fuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina

BACKGROUND The prognostic value of coronary collateral circulation(CC)in patients undergoing chronic total occlusion(CTO)percutaneous coronary intervention(PCI)is *** purpose of the study was to assess the prognostic value of current two CC grading systems and their association with long-term outcomes in patients with CTO underwent *** We consecutively enrolled patients with single-vessel CTO underwent PCI between January 2010 and *** patients were categorized into well-developed or poor-developed collaterals group according to angiographic Werner's CC(grade 2 *** 0–1)or Rentrop(grade 3 *** 0–2)grading *** primary endpoint was 5-year cardiac *** Of 2452 enrolled patients,the overall technical success rate was 74.1%.Well-developed collaterals were present in686 patients(28.0%)defined by Werner's CC grade 2,and in 1145 patients(46.7%)by Rentrop grade *** to Werner's CC grading system,patients with well-developed collaterals had a lower rate of 5-year cardiac death compared with those with poordeveloped collaterals(1.6%vs.3.3%,P=0.02),those with suboptimal recanalization was associated with higher rate of 5-year cardiac death compared with optimal recanalization(4.7%vs.0.8%,P=0.01)and failure patients(4.7%vs.1.6%,P=0.12).However,the similar effect was not shown in Rentrop grading *** In patients with the single-vessel CTO underwent PCI,well-developed collaterals by Werner's CC definition were associated with lower rate of 5-year cardiac ***'s CC grading system had a greater prognostic value than Rentrop grading system in patients with CTO underwent PCI.

关键词： coronary collateral occlusion

Two-dimensional semiconductor heterostructures for photocatalytic CO_(2)conversion

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Science China Chemistry 2024年第8期67卷 2434-2447页

作者： Yang Wu Mingyu Wu Yongfu Sun Yi Xie Hefei national Research center for Physical Sciences at Microscale University of Science and Technology of ChinaHefei 230026China

The CO_(2)reduction into carbon-contained fuel via solar energy offers the powerful tools to realize the zero-emission carbon *** to the intriguing features of the two-dimensional(2D)heterostructures,it is susceptible to modulate the electronic structure as well as the surface geometry for optimizing the photocatalytic CO_(2)*** this perspective,we surveyed the fundamental insights of 2D semiconductor heterostructures,involving the fabrication strategies and classification of the 2D semiconductor ***,we have detailly discussed the overview of 2D semiconductor heterostructure for optimizing CO_(2)photocatalytic influenced factors,including the solar energy utilization,photogenerated carriers separation,and redox reaction ***,we showed the significant advantages of 2D heterostructures in elevating CO_(2)photoreduction performance,focusing on activity,selectivity and *** analyzing the limitations and developments,we ended by putting forward insights into the further researches about the CO_(2)photocatalysts and reactor design,even industrial applications.

关键词： two-dimensional semiconductor heterostructures photocatalysis CO_(2)conversion