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Evidence for distortion-induced local electric polarization in α-RuCl_(3)

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Science China(Physics,Mechanics & Astronomy) 2024年第9期67卷 165-173页

作者： Xinrun Mi de Hou Xiao Wang Sabreen Hammouda Caixing Liu Zijian Xiong Han Li Yan Liu Guiwen Wang Aifeng Wang Yisheng Chai Yang Qi Wei Li Xiaoyuan Zhou Yixi Su dIkhomskii Mingquan He Zhigao Sheng Young Sun College of Physics Center of Quantum Materials and DevicesChongqing UniversityChongqing 401331China Anhui key Laboratory of Condensed Matter Physics at Extreme Conditions High Magnetic Field LaboratoryHefei Institutes of Physical ScienceAnhuiChinese Academy of SciencesHefei 230031 China University of Science and Technology of China Hefei 230026China Jülich Centre for Neutron Scienceat Heinz Maier-Leibnitz Zentrum(JCNS-MLZ) Forschungszentrum Jülich GmbHGarching D-85747Germany School of Physics Beihang UniversityBeijing 100191China Analytical and Testing Center Chongqing UniversityChongqing 401331China State key Laboratory of Surface Physics Department of PhysicsFudan UniversityShanghai 200433China CAS key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China Ⅱ.Physikalisches Institut Universität zu KölnKöln D-50937Germany

The spin-orbit assisted Mott insulator α-RuCl_(3) is a prime candidate for material realization of the kitaev quantum spin *** little attention has been paid to charge degrees of freedom,charge effects,such as electric polarization,may arise in this ***,we report distortion-induced local electric polarization in α-RuCl_(3) as evidenced by single-crystal X-ray diffraction,second harmonic generation(SHG)and dielectric *** SHG signal appears at room temperature and develops substantially in the kitaev paramagnetic state when short-range spin correlations come into *** sizable pyroelectric currents in the kitaev paramagnetic state,the absence of hysteresis in the polarization-electric field(P-E)points to the shortrange nature of electric *** localized electric polarization is likely the result of distortion-induced charge dimerization,achieved through virtual hopping-induced charge *** addition,the electric polarization is boosted by short-range spin correlations via spin-phonon coupling in the kitaev paramagnetic *** results emphasize the importance of charge degrees of freedom in α-RuCl_(3),which establish a novel platform to investigate charge effects in kitaev materials.

关键词： Mott insulator kitaev quantum spin liquid electric polarization

Effect of sodium nitroprusside on the microrheological properties of red blood cells in di®erent media

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Journal of Innovative Optical Health Sciences 2024年第5期17卷 23-31页

作者： Petr Ermolinskiy Matvey Maksimov Andrei Lugovtsov Alexey Muravyov Irina Tikhomirova Alexander Priezzhev Faculty of Physics M.V.Lomonosov Moscow State University Moscow 119991Russia Faculty of Physical Education k.d.Ushinsky Yaroslavl State Pedagogical University Yaroslavl 150000 Russia Faculty of Natural Sciences k.d.Ushinsky Yaroslavl State Pedagogical University Yaroslavl 150000 Russia

Red blood cell(RBC)aggregation as well as their deformation signi¯cantly affects blood *** processes depend on various factors,one of which is concentration of the nitric oxide,one of the main signaling molecule in the *** purpose of this study was to investigate the effect of nitric oxide on the microrheological properties of red blood cells(RBCs)in RBC samples of various media after the addition of nitric oxide donor sodium nitroprusside in *** properties were measured using laser aggregometer and ektacytometer based on diffuse light scattering and diffraction of laser light on a suspension of RBCs,*** study found that heparin-stabilized blood showed increased RBC aggregation and deformation with sodium nitroprusside concentrations of 100,and 200M,while EdTA-stabilized blood showed slightly decreased aggregation and unchanged *** washed RBCs in dextran solution,the addition of sodium nitroprusside(in the concentrations of 100,and 200M)resulted in decreased aggregation and increased ***-ndings aid in our understanding of nitric oxide's effect on RBC microrheological properties.

关键词： Sodium nitroprusside nitric oxide red blood cells RBC aggregation diffuse light scattering laser diffractometer

deformable microlaser force sensing

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Light(Science & Applications) 2024年第6期13卷 1196-1209页

作者： Eleni dalaka Joseph SHill Jonathan H.H.Booth Anna Popczyk Stefan R.Pulver Malte C.Gather Marcel Schubert Centre of Biophotonics SUPASchool of Physics and AstronomyUniversity of St AndrewsNorth HaughSt AndrewsUK Humboldt Centre for Nano-and Biophotonics Department of ChemistryUniversity of CologneKölnGermany School of Psychology and Neuroscience University of St AndrewsSt Mary’s QuadSouth StreetSt AndrewsUK Institute for Bioengineering of Catalonia BarcelonaSpain

Mechanical forces are key regulators of cellular behavior and function,affecting many fundamental biological processes such as cell migration,embryogenesis,immunological responses,and pathological *** force sensors and imaging techniques have been developed to quantify these otherwise invisible forces in single cells and in ***,current techniques rely heavily on high-resolution microscopy and do not allow interrogation of optically dense tissue,reducing their application to 2d cell cultures and highly transparent biological ***,we introduce dEFORM,deformable microlaser force sensing,a spectroscopic technique that detects sub-nanonewton forces with unprecedented spatio-temporal *** is based on the spectral analysis of laser emission from dye-doped oil microdroplets and uses the force-induced lifting of laser mode degeneracy in these droplets to detect nanometer *** validation by atomic force microscopy and development of a model that links changes in laser spectrum to applied force,dEFORM is used to measure forces in 3d and at depths of hundreds of microns within tumor spheroids and late-stage drosophila *** furthermore show continuous force sensing with single-cell spatial and millisecond temporal resolution,thus paving the way for non-invasive studies of biomechanical forces in advanced stages of embryogenesis,tissue remodeling,and tumor invasion.

关键词： invasion otherwise hundreds

Active self-training for weakly supervised 3d scene semantic segmentation

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Computational Visual Media 2024年第3期10卷 425-438页

作者： Gengxin Liu Oliver van kaick Hui Huang Ruizhen Hu College of Computer Science&Software Engineering Shenzhen UniversityShenzhen 518060China School of Computer Science Carleton UniversityOttawa K1S 5B6Canada

Since the preparation of labeled datafor training semantic segmentation networks of pointclouds is a time-consuming process, weakly supervisedapproaches have been introduced to learn fromonly a small fraction of data. These methods aretypically based on learning with contrastive losses whileautomatically deriving per-point pseudo-labels from asparse set of user-annotated labels. In this paper, ourkey observation is that the selection of which samplesto annotate is as important as how these samplesare used for training. Thus, we introduce a methodfor weakly supervised segmentation of 3d scenes thatcombines self-training with active learning. Activelearning selects points for annotation that are likelyto result in improvements to the trained model, whileself-training makes efficient use of the user-providedlabels for learning the model. We demonstrate thatour approach leads to an effective method that providesimprovements in scene segmentation over previouswork and baselines, while requiring only a few userannotations.

关键词： semantic segmentation weakly supervised self-training active learning

Effects of temperature and sodium carboxylate additives on mineralization of calcium oxalate in silica gel systems

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Science China Chemistry 2004年第4期47卷 311-319页

作者： Bernd Tieke Institut fur Physikalische Chemie Universitt zu Kln Luxemburgerstr. 116 D-50939 Kln Germany

The effects of temperature and multifunctional sodium carboxylate additives on the phase composition and morphology of calcium oxalate (CaOxa) crystals grown in silica gel system were systematically investigated using scanning electron microscopy (SEM), powder X-ray diffraction (XRd), and Fourier-transform infrared spectra (FT-IR). The sodium carboxylates investigated include: monocarboxylate sodium acetate (NaAc), disodium tartrate (Na2tart), trisodium citrate (Na3cit), and the disodium salt of ethylenediaminetetraacetic acid (Na2edta). The temperature range was from 7°C to 67°C. The crystallization temperature affects the phase compositions, the growth rate, and the morphology of CaOxa. First, the logarithm of the percentage of calcium oxalate dihydrate (COd) formed at a certain temperature (T) is proportional to the reciprocal of temperature (1/T). Second, the weight of CaOxa crystals decreases as decreasing the temperature. At a given temperature, the ability of the sodium carboxylates to induce COd follows the order: Na2edta Na3cit Na2tart NaAc. Third, the multicarboxylates can decrease the surface area of calcium oxalate monohydrate (COM). It makes the edges and tips of COM crystals blunt and oval. All the three changes, an increase of the content of COd, a decrease of the weight of CaOxa crystals, and a decrease of the surface area of COM crystals, can inhibit the formation of CaOxa stones. These results support the clinical use of citrates and may be helpful in elucidating the mechanisms of the formation of CaOxa calculus. keywords calcium oxalate - sodium carboxylate - gel - urinary calculi - crystallization - biomineralization

关键词： calcium oxalate sodium carboxylate gel urinary calculi crystallization biomineralization

Multi-Model Approach for Assessing the Influence of Calibration Criteria on the Water Balance in Ouémé Basin

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Journal of Water Resource and Protection 2024年第3期16卷 207-218页

作者： Aymar Yaovi Bossa Mahutin Aristide Oluwatobi kpossou Jean Hounkpè Félicien djigbo Badou National Institute of Water University of Abomey-Calavi Cotonou Benin Ecole d’Horticulture et d’Aménagement des Espaces Verts Université Nationale d’Agriculture Kétou Benin

Hydrological models are very useful tools for evaluating water resources, and the hydroclimatic hazards associated with the water cycle. However, their calibration and validation require the use of performance criteria which choice is not straightforward. This paper aims to evaluate the influence of the performance criteria on water balance components and water extremes using two global rainfall-runoff models (HBV and GR4J) over the Ouémé watershed at the Bonou and Savè outlets. Three (3) Efficacy criteria (Nash, coefficient of determination, and kGE) were considered for calibration and validation. The results show that the Nash criterion provides a good assessment of the simulation of the different parts of the hydrograph. kGE is better for simulating peak flows and water balance elements than other efficiency criteria. This study could serve as a basis for the choice of performance criteria in hydrological modelling.

关键词： Hydrological Modelling Performance Criteria Water Balance Ouémé Basin

Molecular Oxygen Abundance in Galactic Massive Star Formation Regions Based on SWAS Observations

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Research in Astronomy and Astrophysics 2024年第9期24卷 83-98页

作者： Bing-Ru Wang di Li Paul F.Goldsmith Jingwen Wu Chao-Wei Tsai donghui Quan Xia Zhang Junzhi Wang Gary J.Melnick Jin-Zeng Li Gary A.Fuller Jinjin Xie National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Tsinghua University Beijing 100084China University of Chinese Academy of Sciences Beijing 100049China Research Center for Astronomical Computing Zhejiang LaboratoryHangzhou 311100China Jet Propulsion Laboratory California Institute of TechnologyPasadenaCA 91109USA Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Guangxi key Laboratory for Relativistic Astrophysics School of Physical Science and TechnologyGuangxi UniversityNanning 530004China Center for Astrophysics Harvard&Smithsonian60 Garden StreetMS 66CambridgeMA 02138USA Jodrell Bank Center for Astrophysics Department of Physics&AstronomyUniversity of ManchesterOxford RoadManchesterM139PLUK I.Physikalisches Institut University of CologneZülpicher Str.7750937 KölnGermany

Molecular oxygen abundance is a key parameter in understanding the chemical network of the interstellar *** estimate the molecular oxygen column density and abundance for a sample of Galactic massive star formation regions based on observations from the Submillimiter Wave Astronomy Satellite(SWAS)*** obtained an averaged O_(2)spectrum based on this sample using the(SWAS)survey data(O_(2),487.249 GHz,N=3-1,J=3-2).No emission or absorption feature is seen around the supposed central velocity with a total integration time of t_(total)=8.67×10^(3)hr and an rms noise per channel of 1.45 m *** a kinetic temperature T_(kin)=30 k,we derive the 3σupper limit of the O_(2)column density to be 3.3×10^(15)cm^(-2),close to the lowest values reported in Galactic massive star formation regions in previous *** corresponding O_(2)abundance upper limit is6.7×10^(-8),lower than all previous results based on SWAS observations and is close to the lowest reported value in massive star formation *** a galactic scale,our statistical results confirm a generally low O_(2)abundance for Galactic massive star formation *** abundance is also lower than results reported in extragalactic sources.

关键词： ISM:molecules galaxies:abundances ISM:lines and bands Galaxy:abundances

Small-signal Stability Constrained Optimal Power Flow Considering Eigenvalue distribution

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Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1052-1062页

作者： Zheng Huang kewen Wang Yi Wang Jing Han Jun Liang the School of Electrical and Information Engineering Zhengzhou UniversityZhengzhou 450001China Cardiff University Cardiff CF243AAU.K.

In the existing small-signal stability constrained op-timal power flow(SSSC-OPF)algorithms,only the rightmost ei-genvalue or eigenvalues that do not satisfy a given threshold,e.g.,damping ratio threshold and real-part threshold of eigen-value,are considered in the small-signal stability *** effect of steady-state,i.e.,operating point,changes on eigen-values is not fully taken into *** this paper,the small-signal stability constraint that can fully reflect the eigenvalue change and system dynamic performance requirement is formed by analyzing the eigenvalue distribution on the complex *** small-signal stability constraint is embedded into the standard optimal power flow model for generation *** simultaneous solution formula of the SSSC-OPF is es-tablished and solved by the quasi-Newton approach,while pen-alty factors corresponding to the eigenvalue constraints are de-termined by the stabilization degree of constrained *** improve the computation speed,a hybrid algorithm for ei-genvalue computation in the optimization process is proposed,which includes variable selection for eigenvalue estimation and strategy selection for eigenvalue *** effectiveness of the proposed algorithm is tested and validated on the New England 10-machine 39-bus system and a modified practical 68-machine 2395-bus system.

关键词： damping ratio eigenvalue optimal power flow quasi-Newton approach sensitivity small-signal stability

Risk factors for long COVId in children and adolescents:a systematic review and meta-analysis

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World Journal of Pediatrics 2024年第2期20卷 133-142页

作者： daniel G.Rayner Elaine Wang Cloris Su Om d.Patel Stephanie Aleluya Alessandra Giglia Evelyn Zhu Maha Siddique department of Health Research Methods Evidenceand ImpactFaculty of Health SciencesMcMaster University1280 Main St WHamiltonONL8S 4K1Canada Faculty of Health Sciences McMaster University1280 Main St WHamiltonON L8S 4K1Canada Faculty of Science McMaster University1280 Main St WHamiltonONL8S 4K1Canada

Background The long-term sequelae of COVId-19 in children and adolescents remain poorly understood and *** systematic review and meta-analysis sought to summarize the risk factors for long COVId in the pediatric *** We searched six databases from January 2020 to May 2023 for observational studies reporting on risk factors for long COVId or persistent symptoms those were present 12 or more weeks post-infection using multivariable regression *** registries,reference lists of included studies,and preprint servers were hand-searched for relevant ***-effects meta-analyses were conducted to pool odds ratios for each risk *** study risk of bias was rated using QUIPS,and the GRAdE framework was used to assess the certainty of evidence for each unique *** Sixteen observational studies(N=46,262)were included,and 19 risk factors were amenable to *** moderate certainty in the evidence,age(per 2-year increase),allergic rhinitis,obesity,previous respiratory diseases,hospitalization,severe acute COVId-19,and symptomatic acute COVId-19 are probably associated with an increased risk of long *** sex,asthma,comorbidity,and heart diseases may be associated with an increased risk of long COVId,and Asian and Black races may be associated with a decreased risk of long *** did not observe any credible subgroup effects for any risk *** The current body of literature presents several compelling risk factors for the development of long COVId in the pediatric *** research is necessary to elucidate the pathophysiology of long COVId.

关键词： COVId-19 Long COVId Post-acute COVId-19 syndrome Pediatrics Risk factors