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Arbitrary topological charge vortex beams from carbon dots random lasers

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Rare Metals 2024年第8期43卷 3844-3853页

作者： xiang-Dong Wang Xiao-Bo Mi jiu-Ru he Feng-Ying Ma Jun-Qiao Wang Li Song Yong-Qiang Zhang Si-Yu Lu Yong-Sheng Hu School of Physics and Microelectronics Zhengzhou UniversityZhengzhou 450001China State Key Laboratory of Reliability and Intelligence of Electrical Equipment and Tianjin Key Laboratory of Electronic Materials and Devices School of Electronics and Information EngineeringHebei University of TechnologyTianjin 300401China Green Catalysis Center College of ChemistryZhengzhou UniversityZhengzhou450001China

Vortex beams have attracted great attention due to their promising applications in the fields of high-capacity optical communication,optical micromanipulation,and quantum information ***,we demonstrate vortex beams with flexible control of the topological charge and modes in a carbon dots random laser for the first *** beams with different types,including the Laguerre-Gaussian(LG),Bessel-Gaussian(BG),LG-superposition,and polarized vortex beams with topological charges up to 50,have been successfully ***,vortex beams can be well realized in carbon dots random lasers with different emission wavelengths covering from 465 to 612 *** work would not only enrich the types of vortex laser,especially for solution-processable lasers,but also provide a new route to realizing multicolor and wavelength-tunable vortex lasers.

关键词： Carbon dots Random lasers Vortex beam Topological charge Spatial light modulator

Elastic three-dimensional phononic topological insulators with Dirac hierarchy

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 54-62页

作者： Shao-Yong Huo Qiu-Shuang Yang jiu-jiu Chen Hong-Kang Li Long-Chao Yao Fu-Chun he Chun-Ming Fu College of Mechanical Engineering University of South ChinaHengyang 421001China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China

Three-dimensional(3D)phononic topological insulators(TIs)featuring two-dimensional(2D)surface states and one-dimensional(1D)hinge states have opened up a new route for multi-dimensional robust wave transport,providing unprecedented methods for integrated acoustic sensors and energy harvesting ***,aiming at the elastic 3D phononic TI with gapless surface states and hinge states,the realization of elastic 3D phononic TIs with gapless surface states and hinge states is a significant challenge due to the complicated multi-mode polarization of elastic waves in 3D *** this study,we demonstrate an elastic 3D phononic TI with a Dirac hierarchy by elaborately operating the corresponding spatial symmetries of the chiral honeycomb ***,a 3D double Dirac cone of elastic wave can be achieved by doubling the lattice along the outof-plane direction to fold two iso-frequency Weyl *** topological phase transitions and 2D gapless two-fold Dirac surface states of elastic wave are realized by breaking the half-lattice spatial translation ***,based on the Brillouin zone folding along the in-plane direction,the 2D gapless two-fold surface Dirac cones are folded into four-fold surface Dirac ***,by inducing the relative radius of adjacent holes to break the in-plane spatial inversion symmetry,the fourfold surface Dirac cones are gapped and associated with a surface state inversion,in which the gapless 1D hinge Dirac dispersion is *** research offers a route for engineering the hierarchies of TIs in 3D elastic wave systems and provides new possibilities for designing 3D ultrasonic devices with unconventional functions.

关键词： Dirac topological hierarchy

Symmetrization of quasi-regular patterns with periodic tilting of regular polygons

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Computational Visual Media 2024年第3期10卷 559-576页

作者： Zhengzheng Yin Yao Jin Zhijian Fang Yun Zhang Huaxiong Zhang jiu Zhou Lili he School of Computer Science and Technology Zhejiang Sci-Tech UniversityHangzhou 310018China Zhejiang Provincial Innovation Center of Advanced Textile Technology Shaoxing 312000China School of Media Engineering Communication University of ZhejiangHangzhou 310018China

Computer-generated aesthetic patterns arewidely used as design materials in various fields. Themost common methods use fractals or dynamicalsystems as basic tools to create various patterns. Toenhance aesthetics and controllability, some researchershave introduced symmetric layouts along with thesetools. One popular strategy employs dynamical systemscompatible with symmetries that construct functionswith the desired symmetries. However, these aretypically confined to simple planar symmetries. Theother generates symmetrical patterns under theconstraints of tilings. Although it is slightly moreﬂexible, it is restricted to small ranges of tilingsand lacks textural variations. Thus, we proposed anew approach for generating aesthetic patterns bysymmetrizing quasi-regular patterns using general kuniformtilings. We adopted a unified strategy toconstruct invariant mappings for k-uniform tilings thatcan eliminate texture seams across the tiling ***, we constructed three types of symmetriesassociated with the patterns: dihedral, rotational, andreﬂection symmetries. The proposed method can beeasily implemented using GPU shaders and is highlyefficient and suitable for complicated tiling with regularpolygons. Experiments demonstrated the advantages of our method over state-of-the-art methods in terms ofﬂexibility in controlling the generation of patterns withvarious parameters as well as the diversity of texturesand styles.

关键词： quasi-regular patterns(QRP) k-uniform tilings invariant mappings symmetry aesthetic patterns

Research on Pulsar Time Steered Atomic Time Algorithm Based on DPLL

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Research in Astronomy and Astrophysics 2024年第3期24卷 237-248页

作者： Ze-Hao Zheng Yang Liu Dan Shen Fan Feng jiu-Long Liu Yue-Xin Ma xiang-Wei Zhu School of Electronic and Communication Engineering Sun Yat-sen UniversityShenzhen 518107China School of Aeronautics and Astronautics Sun Yat-sen UniversityShenzhen 518107China School of Systems Science and Engineering Sun Yat-sen UniversityGuangzhou 510275China

In today’s society,there is a wide demand for high-precision and high-stability time service in the fields of electric power,communication,transportation and *** present,the time standard in various countries is mainly based on atomic clocks,but the frequency drift of atomic clocks will affect the long-term stability *** with atomic clocks,millisecond pulsars have better long-term stability and can complement with the excellent short-term stability of atomic *** order to improve the long-term stability of the atomic timescale,and then improve the timing accuracy,this paper proposes an algorithm for steering the atomic clock ensemble(ACE)by ensemble pulsar time(EPT)based on digital phase locked loop(DPLL).First,the ACE and EPT are generated by the ALGOS algorithm,then the ACE is steered by EPT based on DPLL to calibrate the long-term frequency drift of the atomic clock,so that the generated steered atomic time follows both the short-term stability characteristics of ACE and the long-term stability characteristics of EPT,and finally,the steered atomic time is used to calibrate the local cesium *** experimental results show that the long-term stability of atomic time after steering is improved by 2 orders of magnitude compared with that before steering,and the daily drift of a local cesium clock after calibration is less than 9.47 ns in 3 yr,3 orders of magnitude higher than that before calibration on accuracy.

关键词： (stars) pulsars general-time-methods data analysis-instabilities

A generalization of Banach's lemma and its applications to perturbations of bounded linear operators

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Applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 363-369页

作者： WANG Zi DING jiu WANG Yu-wen School of Mathematics Sciences Harbin Normal UniversityHarbin 150025China School of Mathematics and Natural Sciences The University of Southern MississippiHattiesburg MS 39406-5043USA Academic Committee Harbin Institute of PetroleumHarbin 150027China

Let X be a Banach space and let P:X→X be a bounded linear *** an algebraic inequality on the spectrum of P,we give a new sufficient condition that guarantees the existence of(I-P)^(-1) as a bounded linear operator on X,and a bound on its spectral radius is also *** generalizes the classic Banach *** apply the result to the perturbation analysis of general bounded linear operators on X with commutative perturbations.

关键词： Banach lemma spectral radius generalized inverse perturbation analysis

Advancing neuroscience through real-time processing of big data:Transition from open-loop to closed-loop paradigms

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Zoological Research 2024年第3期45卷 518-519页

作者： Yu-Fan Wang jiu-Lin Du Institute of Neuroscience State Key Laboratory of NeuroscienceCenter for Excellence in Brain Science and Intelligence TechnologyChinese Academy of SciencesShanghai 200031China University of Chinese Academy of Sciences Beijing 100049China School of Life Science and Technology ShanghaiTech UniversityShanghai 200031China

The brain functions as a closed-loop system that continuously generates behavior in response to the external environment and adjusts actions based on the *** research methodologies in neuroscience,especially those employed in brain imaging experiments,have mainly adopted an open-loop paradigm(Grosenick et al.,2015).Functional neural circuits are analyzed offline and subsequently tested through manipulation of neuronal activities within specific regions or with genetic *** establishing a closed-loop research paradigm,functional ensembles can be detected and tested in real time with temporal *** functional ensembles,rather than brain regions or genetically labeled neural populations,serve as fundamental units of neural networks,offering valuable insights into the dissection of neural *** closed-loop research paradigm also enables the capture of high-dimensional activities of internal brain dynamics and precise elucidation of physiological processes such as learning,decision-making,and sleep.

关键词： neural loop Transition

Fractal Characteristics and Main Controlling Factors of High-Quality Tight Sandstone Reservoirs in the Southeastern Ordos Basin

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Journal of Earth Science 2024年第2期35卷 631-641页

作者： Ruilin Hao Wenhui Huang jiu Bo Li Yuan Key Laboratory for Marine Reservoir Evolution and Hydrocarbon Abundance Mechanism School of Energy ResourcesChina University of GeosciencesMinistry of EducationBeijing100083China

Due to the complex conditions and strong heterogeneity of tight sandstone reservoirs,the reservoirs should be classified and the controlling factors of physical properties should be *** thin section observations,cathodoluminescence,scanning electron microscopy(SEM),X-ray diffraction(XRD),and high-pressure mercury injection(HPMI)were used to classify and optimize the *** Brooks-Corey model and stepwise regression were used to study the fractal dimension and main controlling factors of the physical properties of the high-quality *** results show that the reservoirs in the study area can be divided into four types,and the high-quality reservoir has the best physical properties and pore-throat *** the high-quality reservoir,the homogeneity of transitional pores was the best,followed by that of micropores,and the worst was *** porosity was controlled by depth and *** model with standardized coefficients is y=12.454−0.778×(Depth)+0.395×(Kaolinite).The permeability was controlled by depth,illite/montmorillonite,and siliceous cement,and the model with standardized coefficients is y=1.689−0.683×(Depth)−0.395×(Illite/Montmorillonite)−0.337×(Siliceous Cement).The pore-throat evolutionary model shows that the early-middle diagenetic period was when the reservoir physical properties were at their best,and the kaolinite intercrystalline pores and residual intergranular pores were the most important.

关键词： fractal dimension main controlling factors stepwise regression high-quality tight sandstone reservoir Ordos Basin petroleum geolgoy

Microvascular structural changes in esophageal squamous cell carcinoma pathology according to intrapapillary capillary loop types under magnifying endoscopy

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World Journal of Gastrointestinal Oncology 2024年第8期16卷 3471-3480页

作者： Wei-Yang Shu Yan-Yan Shi jiu-Tian Huang Ling-Mei Meng he-Jun Zhang Rong-Li Cui Yuan Li Shi-Gang Ding Department of Gastroenterology Peking University Third HospitalBeijing 100191China Research Center of Clinical Epidemiology Peking University Third HospitalBeijing 10019China Department of Gastroenterology Pathology Laboratory Peking University Third HospitalBeijing 100191China Department of Gastroenterology Peking University International HospitalBeijing 102206China

BACKGROUND The intrapapillary capillary loop(IPCL)characteristics,visualized using magnifying endoscopy,are commonly assessed for preoperative evaluation of the infiltration depth of esophageal squamous cell carcinoma(ESCC).Japan Esophageal Society(JES)classification is the most widely used *** structural changes are evaluated by magnifying endoscopy for the presence or absence of each morphological factor:tortuosity,dilatation,irregular caliber,and different ***,the pathological characteristics of IPCLs have not been thoroughly investigated,especially the microvascular structures corresponding to the deepest parts of the lesions'*** To investigate differences in pathological microvascular structures of ESCC,which correspond to the deepest parts of the lesions'*** Patients with ESCC and precancerous lesions diagnosed at Peking University Third Hospital were enrolled between January 2019 and April *** first underwent magnified endoscopic examination,followed by endoscopic submucosal dissection or surgical *** images were scanned using a threedimensional slice scanner,and the pathological structural differences in different types,according to the JES classification,were analyzed using nonparametric tests and *** The 35 lesions were divided into four groups according to the JES classification:A,B1,B2,and *** analyses revealed significant differences(aPhe short and long calibers,area,location,and density between types A and ***,there were no significant differences in these parameters between types B1 and B2 and between types B2 and B3(P>0.05).However,significant differences in the short calibers,long calibers,and area of IPCL were observed between types B1 and B3(aPhe density or location(P>0.05).CONCLUSION Pathological structures of IPCLs in the deepest infiltrating regions differ among va

关键词： Esophageal squamous cell carcinoma Intrapapillary capillary loop The Japan Esophageal Society classification Magnifying endoscopy Pathological characteristics

Response of ocean acidification to atmospheric carbon dioxide removal

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Journal of Environmental Sciences 2024年第6期140卷 79-90页

作者： jiu Jiang Long Cao Xiaoyu Jin Zechen Yu Han Zhang Jianjie Fu Guibin Jiang School of Environment Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Key Laboratory of Geoscience Big Data and Deep Resources of Zhejiang Province School of Earth SciencesZhejiang UniversityHangzhou 310058China Zhejiang Climate Center Hangzhou 310052China

Artificial CO_(2)removal from the atmosphere(also referred to as negative CO_(2)emissions)has been proposed as a potential means to counteract anthropogenic climate *** we use an Earth system model to examine the response of ocean acidification to idealized atmospheric CO_(2)removal *** our simulations,atmospheric CO_(2)is assumed to increase at a rate of 1%per year to four times its pre-industrial value and then decreases to the pre-industrial level at a rate of 0.5%,1%,2%per year,*** results show that the annual mean state of surface ocean carbonate chemistry fields including hydrogen ion concentration([H^(+)]),pH and aragonite saturation state respond quickly to removal of atmospheric CO_(2).However,the change of seasonal cycle in carbonate chemistry lags behind the decline in atmospheric CO_(2).When CO_(2)returns to the pre-industrial level,over some parts of the ocean,relative to the pre-industrial state,the seasonal amplitude of carbonate chemistry fields is substantially *** results also show that changes in deep ocean carbonate chemistry substantially lag behind atmospheric CO_(2)*** CO_(2)returns to its pre-industrial value,the whole-ocean acidity measured by[H^(+)]is 15%-18%larger than the pre-industrial level,depending on the rate of CO_(2)*** study demonstrates that even if atmospheric CO_(2)can be lowered in the future as a result of net negative CO_(2)emissions,the recovery of some aspects of ocean acidification would take decades to centuries,which would have important implications for the resilience of marine ecosystems.

关键词： Carbon dioxide removal Net negative CO_(2)emission Ocean acidification Climate change Earth system modeling