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Westward Migration of Tropical Cyclone Activity in the Western North Pacific during 1982–2020:Features and Possible Causes

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Journal of Meteorological Research 2024年第1期38卷 1-9页

作者： Jian ZHONG Huadong DU Yuqin WU Yuehua PENG China Satellite Maritime Tracking and Control department Jiangyin 2144312 College of Advanced interdisciplinary Studies National University of Defense TechnologyChangsha 4100733 Dalian Naval Academy Dalian 1160184 Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029

The westward migration of tropical cyclone(TC)activity has been identified in the western North Pacific(WNP),but the related features and causes remain ***,based on the best track data from China,Japan,and the US,and the NCEP–NCAR reanalysis data in 1982–2020,we investigate characteristics of the westward migration of the WNP TC activity with various metrics,and reveal possible causes for the migration of TC tracks through analyzing its seasonality and dependence on environmental *** results show that the WNP TCs show significant westward migrations in a number of metrics,including location of tracks,genesis,the first track point at which TC reaches its lifetime-maximum intensity,and the last track point in the TC *** is found that TC tracks exhibit more significant westward migrations in the easterly steering flow than in the westerly steering ***,the TC longitude shift shows notable seasonal variations,for which the TCs in the easterlies move further west than those in the westerlies during July–September,vice versa during October–*** dependence of the westward migration of TC tracks on background steering flow is associated with the different environmental *** westward shift in the westerly steering is mainly due to the reduced vertical wind shear(VWS),while the weakened zonal easterly steering and reduced VWS are both closely related to the westward migration in the easterly *** results have important implications for understanding current and future variations in TC longitude shift.

关键词： tropical cyclone westward migration steering flow vertical wind shear

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Secure Transmission of Compressed Medical Image Sequences on Communication Networks Using Motion Vector Watermarking

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Computers, Materials & Continua 2024年第3期78卷 3283-3301页

作者： Rafi Ullah Mohd Hilmi bin Hasan Sultan Daud Khan Mussadiq Abdul Rahim Computer and Information sciences department Universiti Teknologi PETRONASBandar Seri Iskandar Perak32610Malaysia department of Computer Science National University of TechnologyIslamabad46000Pakistan interdisciplinary Research Center for Intelligent Secure Systems King Fahd University of Petroleum and MineralsDammam31261Saudi Arabia

Medical imaging plays a key role within modern hospital management systems for diagnostic *** methodologies are extensively employed to mitigate storage demands and enhance transmission speed,all while upholding image ***,an increasing number of hospitals are embracing cloud computing for patient data storage,necessitating meticulous scrutiny of server security and privacy ***,considering the widespread availability of multimedia tools,the preservation of digital data integrity surpasses the significance of compression *** response to this concern,we propose a secure storage and transmission solution for compressed medical image sequences,such as ultrasound images,utilizing a motion vector watermarking *** watermark is generated employing an error-correcting code known as Bose-Chaudhuri-Hocquenghem(BCH)and is subsequently embedded into the compressed sequence via block-based motion *** the process of watermark embedding,motion vectors are selected based on their magnitude and phase *** embedding watermarks,no specific spatial area,such as a region of interest(ROI),is used in the *** embedding of watermark bits is dependent on motion *** reversible watermarking allows the restoration of the original image sequences,we use the irreversible watermarking *** reason for this is that the use of reversible watermarks may impede the claims of ownership and legal *** restoration of original data or images may call into question ownership or other legal *** peak signal-to-noise ratio(PSNR)and structural similarity index(SSIM)serve as metrics for evaluating the watermarked image *** all images,the PSNR value exceeds 46 dB,and the SSIM value exceeds *** results substantiate the efficacy of the proposed technique in preserving data integrity.

关键词： Block matching algorithm(BMA) compression full-search algorithm motion vectors ultrasound image sequence watermarking

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Assessment of phytochemicals, antioxidant, anti-hemolytic, anti-inflammatory and anti-cancer potential of flowers, leaves and stem extracts of Rosa arvensis

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Journal of Traditional Chinese Medicine 2024年第4期44卷 804-812页

作者： Zubaria Tul Ain Iram Fatima Sana Naseer Sobia Kanwal Tariq Mahmood department of Plant sciences Quaid-i-Azam University department of Biology Allama Iqbal Open University department of Plant sciences Faculty of Biological SciencesQuaid-i-Azam University Pakistan Academy of sciences

OBJECTIVE: To evaluate phytochemicals and in vitro biological potential of flowers, leaves and stem extracts of Rosa arvensis. METHODS: Presence of twenty secondary metabolites was confirmed and then phenolic and flavonoid contents were quantified spectrophotometrically. Fourier Transform Infrared spectroscopy was conducted to ascertain functional groups and antioxidant potential was examined using 2,2-diphenyl-1-picrylhydrazyl scavenging activity, total antioxidant capacity and total reducing power *** erythrocytes were used to assess anti-hemolytic activity and five bacterial strains were examined to determine antibacterial potential of plant extracts. Radish seeds were used to perform phytotoxic activity and cytotoxic potential was evaluated via brine shrimps and PC3 cell lines. RESULTS: Highest phenolic contents were detected in the methanolic extract of Rosa arvensis flower（RAFM） [（151.635 ± 0.005） gallic acid equivalent mg/g] and highest flavonoid contents in the chloroform leaf extract（RALC） [（108.228 ± 0.004） quercetin equivalent mg/g]. Fourier-transform infrared spectroscopy analysis showed the presence of wide range of functional groups. The antioxidant assays indicated highest DPPH scavenging activity [IC50（23.5 ± 0.6） μg/mL] in the methanolic stem extract（RASM）, highest total antioxidant capacity [（265.1 ± 0.9） μg/mL] in RAFM and highest reducing potential [（209.9 ± 0.6） μg/mL] in leaf extract（RALM）. Highest antihemolytic activity [（90.0 ± 0.5） μg/mL] was recorded in RAFM and brine shrimp cytotoxicity potential [（52.3 ± 0.3） μg/mL] in RASM. The antimicrobial activity was detected highest [（21.1 ± 0.5） mm inhibition zones] in RALM against Streptococcus aureus. In the end, antiinflammatory and anti-cancer activity results depicted less than 50 % inhibition in the methanolic extracts. CONCLUSIONS: Our findings will be helpful in designing pharmaceutical regimens and therefore, more studies can be recommended to isolate and characterize compounds as

关键词： PC-3 cells anti-inflammatory agents hemolysis oxidative stress spectroscopy, fourier transform infrared

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Visible light-driven photo remediation of hazardous cationic dye via Ce-doped WO_(3) nanostructures

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Journal of Rare Earths 2024年第5期42卷 869-878,I0003页

作者： Azra Haroon Kaseed Anwar Arham S.Ahmed department of Physics Aligarh Muslim University202002AligarhIndia interdisciplinary Nanotechnology Centre Aligarh Muslim University202002AligarhIndia

Ce-doped WO_(3) nanoparticles were successfully synthesized by the sol-gel method and characterized through advanced characterization *** high resolution transmission electron microscopy(HRTEM)and scanning electron microscopy(SEM)results show a reduction in the agglomeration of nanoparticles upon *** energy dispersive X-ray(EDX)analysis validates the existence of the Ce element in all the doped samples.X-ray photoelectron spectroscopy(XPS)and Raman spectra justify the presence of structural defects(oxygen vacancies)and successful formation of the monoclinic WO_(3) phase,*** Kubelka-Munk function indicates a decrease in band gap with doping,while photoluminescence(PL)spectra show intense visible and UV emissions,Significantly,all doped samples exhibit higher photocatalytic performance than pure WO_(3) nanoparticles,with the 6 wt%Ce-doped sample displaying the highest degradation *** with Ce can help to increase the surface area of WO_(3),thereby improving its photoactivity,Moreover,a correlation between PL and photocatalysis is established in the light of oxygen vacancies suggesting a direct dependence of high photocatalytic activity on strong PL signals of WO_(3) *** experiments further reveal that the degradation process is primarily driven by active species,providing insight into a plausible photocatalytic mechanism.

关键词： WO_(3) Rare-earth element Environmental crisis Oxygen vacancies Luminescence Photocatalysis

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Global weirding at mass extinction horizons

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National Science Review 2024年第1期11卷 10-12页

作者： Gregory J.Retallack department of Earth sciences University of Oregon

A strong motivation for studying mass extinctions is understanding how current climatic and biodiversity crises will affect creatures living on land such as ourselves. Perhaps the question is: how bad can it get? In that case, terrestrial Permian-Triassic mass extinctions are an irresistible worst-case scenario [1].

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Multi-region calcium imaging in freely behaving mice with ultra-compact head-mounted fluorescence microscopes

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National Science Review 2024年第1期11卷 161-173页

作者： Feng Xue Fei Li Ke-ming Zhang Lufeng Ding Yang Wang Xingtao Zhao Fang Xu Danke Zhang Mingzhai Sun Pak-Ming Lau Qingyuan Zhu Pengcheng Zhou Guo-Qiang Bi department of Precision Machinery and Precision Instruments University of Science and Technology of China Hefei National Laboratory for Physical sciences at the Microscale University of Science and Technology of China interdisciplinary Center for Brain Information the Brain Cognition and Brain Disease Institute Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Faculty of Life and Health sciences Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences School of Life sciences University of Science and Technology of China Institute of Semiconductors Chinese Academy of Sciences department of Modern Life sciences and Biotecnology Xiongan Institute of Innovation Xiongan New Area Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions Suzhou Institute for Advanced Research University of Science and Technology of China Institute of Artiflcial Intelligence Hefei Comprehensive National Science Center

To investigate the circuit-level neural mechanisms of behavior, simultaneous imaging of neuronal activity in multiple cortical and subcortical regions is highly desired. Miniature head-mounted microscopes offer the capability of calcium imaging in freely behaving animals. However, implanting multiple microscopes on a mouse brain remains challenging due to space constraints and the cumbersome weight of the ***, we present TINIscope, a Tightly Integrated Neuronal Imaging microscope optimized for electronic and opto-mechanical design. With its compact and lightweight design of 0.43 g, TINIscope enables unprecedented simultaneous imaging of behavior-relevant activity in up to four brain regions in ***-of-concept experiments with TINIscope recorded over 1000 neurons in four hippocampal subregions and revealed concurrent activity patterns spanning across these regions. Moreover, we explored potential multi-modal experimental designs by integrating additional modules for optogenetics, electrical stimulation or local field potential recordings. Overall, TINIscope represents a timely and indispensable tool for studying the brain-wide interregional coordination that underlies unrestrained behaviors.

关键词： miniature microscope multiple sites calcium imaging multimodal integration hippocampus

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A historical overview of nano-optics:From near-field optics to plasmonics

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Chinese Physics B 2024年第5期33卷 134-145页

作者：邓妙怡朱星 department of History of Science Technology and MedicineAcademy for Advanced Interdisciplinary StudiesPeking UniversityBeijing 100871China School of Physics Peking UniversityBeijing 100871China

Nano-optics is an emergent research field in physics that appeared in the 1980s,which deals with light–matter optical interactions at the nanometer *** early studies of nano-optics,the main concern focus is to obtain higher optical resolution over the diffraction *** researches of near-field imaging and spectroscopy based on scanning near-field optical microscopy(SNOM)are *** exploration of improving SNOM probe for near-field detection leads to the emergence of surface *** the sense of resolution and wider application,there has been a significant transition from seeking higher resolution microscopy to plasmonic near-field modulations in the nano-optics community during the nano-optic ***,studies of nano-optics prefer the investigation of plasmonics in different material *** this article,the history of the development of near-field optics is briefly *** difficulties of conventional SNOM to achieve higher resolution are *** an alternative solution,surface plasmons have shown the advantages of higher resolution,wider application,and flexible nano-optical modulation for new *** typical studies in different periods are introduced and characteristics of nano-optics in each stage are *** this way,the evolution progress from near-field optics to plasmonics of nano-optics research is *** future development of nano-optics is discussed then.

关键词： nano-optics near-field optics surface plasmon plasmonic modulation

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Existence and asymptotics of normalized solutions for the logarithmic Schr?dinger system

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Science China Mathematics 2024年第9期67卷 2019-2048页

作者： Qian Zhang Wenming Zou department of Mathematical sciences Tsinghua University

This paper is concerned with the following logarithmic Schr?dinger system:■where Ω=RNor Ω?RN（N≥3） is a bounded smooth domain,and ωi∈R,μi,ρi> 0 for i=1,***,p,q≥1,and 2≤p+q≤2*,where 2*:=2N/N-2. By using a Gagliardo-Nirenberg inequality and a careful estimation of u log u2,firstly,we provide a unified proof of the existence of the normalized ground state solution for all 2≤p+q ≤2*.Secondly,we consider the stability of normalized ground state ***,we analyze the behavior of solutions for the Sobolev-subcritical case and pass to the limit as the exponent p+q approaches 2*.Notably,the uncertainty of the sign of u log u2in（0,+∞） is one of the difficulties of this paper,and also one of the motivations we are interested *** particular,we can establish the existence of positive normalized ground state solutions for the Brézis-Nirenberg type problem with logarithmic perturbations（i.e.,p+q=2*）.In addition,our study includes proving the existence of solutions to the logarithmic type Bréis-Nirenberg problem with and without the *** ∫Ω|ui|2dx=ρi（i=1,2） by two different methods,*** results seem to be the first result of the normalized solution of the coupled nonlinear Schr?dinger system with logarithmic perturbations.

关键词： logarithmic Schrödinger system Brézis-Nirenberg problem normalized solution existence and stability behavior of solutions

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Analysis of ancient mass extinction recoveries in marine environments: generating strategies for managing outcomes of the current mass extinction

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National Science Review 2024年第1期11卷 8-10页

作者： David J.Bottjer department of Earth sciences University of Southern California

The defining feature of a mass extinction and its associated recovery is the global amount of extinction that occurred[1]. However, there is finer-scale detail to the story, as seen in the ongoing modern mass extinction(the sixth mass extinction), which exhibits variable effects among marine ecosystems and environments, and hence geographic areas [1].

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Late Ordovician Mass Extinction: Earth, fire and ice

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National Science Review 2024年第1期11卷 51-65页

作者： David A.T.Harper Palaeoecosystems Group Department of Earth SciencesDurham University

The Late Ordovician Mass Extinction was the earliest of the ‘big’ five extinction events and the earliest to affect the trajectory of metazoan life. Two phases have been identified near the start of the Hirnantian period and in the middle. It was a massive taxonomic extinction, a weak phylogenetic extinction and a relatively benign ecological extinction. A rapid cooling, triggering a major ice age that reduced the temperature of surface waters, prompted a drop in sea level of some 100 m and introduced toxic bottom waters onto the shelves. These symptoms of more fundamental planetary processes have been associated with a range of factors with an underlying driver identified as volcanicity. Volcanic eruptions, and other products, may have extended back in time to at least the Sandbian and early Katian, suggesting the extinctions were more protracted and influential than hitherto documented.

关键词： Ordovician LOME paleoecology palaeobiogeography biotas

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