We propose that a perfect vortex beam (PVB) exhibits three major properties, namely, perfect property, self-focusing property, and self-healing property. Our experimental results indicate that PVB manifests superb perfect property, impervious to the influence of orbital angular momentum during the anti-diffraction stage, but ultimately transitioning to the self-focusing property during the self-focusing stage. The self-focusing property of PVB can significantly augment its transmission performance and be tailored through adjustments to the ring radius, ring thickness, and self-focusing ratio to meet the needs of various optical applications.
View Article and Find Full Text PDFSatisfactory reduction of some displaced pediatric supracondylar humerus fractures is not achievable via closed reduction, thus necessitating open procedure, which increases the incidence of complications. Using percutaneous prying-up technique to assist closed reduction may reduce the requirement for transform to an open operation. We retrospectively reviewed displaced pediatric supracondylar humerus fractures treated by the same surgeon from September 2021 to January 2024,with 134 subjects meeting criteria for inclusion.
View Article and Find Full Text PDFWe report an experimental investigation into the tight-focusing characteristics of linearly polarized inverse circular Airy beams (ICABs). Our study reveals that tightly focused ICABs exhibit Bessel-like, needle-like, or dual foci profiles depending on whether the main ring's radius is smaller than, equal to, or larger than the critical radius. The emergence of the dual foci structure is attributed to the constrained entrance aperture of the microscope objective (MO).
View Article and Find Full Text PDFWe propose a scheme to control the Goos-Hänchen (GH) shift of TE and TM reflected light beams in a double-prism structure, where a three-level Raman gain medium is filling the gap between the two prisms. We find that it is possible to control the GH shift in this structure by externally adjusting the optical properties of the Raman gain atomic medium while the gap width between the two prisms is fixed. Inspired by recent successful implementation of the double-prism configuration with an air gap to measure the GH shift, we expected that our proposal to control the GH shift can be achieved experimentally and used in different potential applications of the GH shift.
View Article and Find Full Text PDFThe influence of spatial dispersion of metals on phase and Goos-Hänchen (GH) shifts near the reflection dip has been investigated in the Kretschmann-Raether configuration, within the hydrodynamic model framework. We have derived an analytical expression of the reflection coefficient and discussed the optical properties when the nonlocality of metals based on the phenomenological model and Kretchmann's theory is taken into account. Our results show that nonlocality has a significant impact for large wavevectors and causes a shift of the critical point corresponding to the total absorption.
View Article and Find Full Text PDFWe report experimental realization and manipulation of optical tornado waves (ToWs). By controlling the self-focusing length, total angular momentum, and foci deviation of ToWs, the propagation properties of optical ToWs, especially their angular velocity, can be manipulated. Controlling the accumulated rotation angle of the main intensity lobes of ToWs from 0° through 1100° is experimentally demonstrated, and their angular velocity is predicted to be the highest around the foci overlap situation.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
March 2022
Light propagation on a two-dimensional curved surface embedded in a three-dimensional space has attracted increasing attention as an analog model of four-dimensional curved spacetime in the laboratory. Despite recent developments in modern cosmology on the dynamics and evolution of the universe, investigation of nonlinear dynamics of light on non-Euclidean geometry is still scarce, with fundamental questions, such as the effect of curvature on deterministic chaos, challenging to address. Here, we study classical and wave chaotic dynamics on a family of surfaces of revolution by considering its equivalent conformally transformed flat billiard, with nonuniform distribution of the refractive index.
View Article and Find Full Text PDFFractional vortex beams (FVBs) were believed to be hard to rotate microparticles at a half-integer topological charge due to the unique radial opening (low-intensity gap) in their intensity ring. However, recent research discovered more symmetric intensity structures with less intensity inhomogeneity of practical FVBs at the focal plane. Here, we experimentally demonstrated the manipulation of trapped microparticles and precisely measured their rotation periods at the focal plane of practical FVBs by using a high-speed camera.
View Article and Find Full Text PDFLncRNAs exert comprehensive effects in regulating the initiation and deterioration of hepatocellular carcinoma (HCC). However, the specific expression profiles and functional mechanisms of LINC00536 in HCC need to be disclosed. The study is intended to clarify the leverage of LINC00536 in HCC and investigate the potential mechanisms for the regulatory role of LINC00536 in the progression of HCC.
View Article and Find Full Text PDFIn this work, we study the effects of nonlocality on the optical response near surface plasmon resonance of the Otto structure, and such nonlocality is considered in the hydrodynamic model. Through analyzing the dispersion relations and optical response predicted by the Drude's and hydrodynamic model in the system, we find that the nonlocal effect is sensitive to the large propagation wavevector, and there exists a critical incident angle and thickness. The critical point moves to the smaller value when the nonlocal effect is taken into account.
View Article and Find Full Text PDFSpeciation is a process whereby the evolution of reproductive barriers leads to isolated species. Although many studies have addressed large-effect genetic footprints in the advanced stages of speciation, the genetics of reproductive isolation in nascent stage of speciation remains unclear. Here, we show that pig domestication offers an interesting model for studying the early stages of speciation in great details.
View Article and Find Full Text PDFWe investigate the self-healing property of focused circular Airy beams (FCAB), and this property is associated with the transverse Poynting vector (energy flow) for a better interpretation. We both experimentally and numerically show the effect of the obstruction's position, size and shape on the self-healing property of FCAB. It is found that FCAB will heal if the obstruction is placed at the area between the two foci of FCAB, and it has the least influence on the FCAB when the obstruction is placed near the lens' rear focal plane, whereas FCAB cannot heal if the obstruction is out of the area between two foci.
View Article and Find Full Text PDFHanbury Brown and Twiss (HBT) effect has broad applications in optics and other branches of physics, and traditionally this effect is considered in pure spatial or temporal domain. Here we investigate the spatiotemporal HBT effect, extending this phenomenon from spatial or temporal to spatiotemporal domain. By assuming the Gaussian statistics of partially coherent spatiotemporal pulsed sources, we find the generalized analytical results for spatiotemporal HBT effect in the compact form, with the help of the matrix-optics method, which can consider the HBT effect in spatial and temporal domain simultaneously.
View Article and Find Full Text PDFNeonicotinoid insecticides (NNIs) are the most widely used insecticides in China and worldwide. Continuous use of NNIs can lead to their accumulation in soil, causing potential ecological risks due to their relatively long half-life. We used liquid chromatography-tandem mass spectrometry (LC-MS/MS) to investigate the residual levels of nine neonicotinoids in greenhouse soils in Shouguang, East China, at different soil depths and with different crops (tomato and cucumber) after varying periods of cultivation.
View Article and Find Full Text PDFThe understanding of soil microbiome is important for sustainable cultivation, especially under greenhouse conditions. Here, we investigated the changes in soil pesticide residues and microbial diversity and community structure at different cultivation years under a greenhouse system. The 9-to-14 years sites were found to have the least diversity/rich microbial population as compared to sites under 8 years and over 16 years, as analyzed with alpha diversity index.
View Article and Find Full Text PDFYing Yong Sheng Tai Xue Bao
April 2019
One-off fertilization is a new technology of one-time applying base fertilizer near the rhizosphere during whole crop cultivation period. It has the advantages of simplifying fertilization manage-ment and reducing labor costs, but its impacts on environment, such as leaching characteristics need further analysis. We set five treatments in the typical rice-rape rotation system in the middle and lower reaches of the Yangtze River, including control treatment (CK), farmers' practice treatment (FP), optimal fertilizer treatment (OPT), one-off application of urea fertilizer treatment (UA) and one-off application of controlled release urea treatment (CRF).
View Article and Find Full Text PDFFractional vortex beams (FVBs) with non-integer topological charges attract much attention due to unique features of propagations, but different viewpoints still exist on the change of their total vortex strength. Here we have experimentally demonstrated the distribution and number of vortices contained in FVBs at the Fraunhofer diffraction region. We have verified that the jumps of total vortex strength for FVBs happen only when non-integer topological charge is before and after (but very close to) any even integer number that originates from two different mechanisms for generation and movement of vortices on focal plane.
View Article and Find Full Text PDFInvestigation of physics on two-dimensional curved surface has significant meaning in study of general relativity, inasmuch as its realizability in experimental analogy and verification of faint gravitational effects in laboratory. Several phenomena about dynamics of particles and electromagnetic waves have been explored on curved surfaces. Here we consider Wolf effect, a phenomenon of spectral shift due to the fluctuating nature of light fields, on an arbitrary surface of revolution (SOR).
View Article and Find Full Text PDFGliomas are the most common central nervous system tumors. They show malignant characteristics indicating rapid proliferation and a high invasive capacity and are associated with a poor prognosis. In our previous study, p68 was overexpressed in glioma cells and correlated with both the degree of glioma differentiation and poor overall survival.
View Article and Find Full Text PDFAgricultural management techniques such as fertilizer or manure application have substantial influence on NH and NO emissions and, by understanding this influence, management strategies can be developed to reduce them. An experiment was conducted in a greenhouse at Hunan Agricultural University during 2012 to 2013, to investigate effects of different fertilizers on NH and NO emissions. The treatments included control without fertilizer (CK), swine composting fertilizer (SC), stored swine manure fertilizer (SS), and chemical fertilizer (FC).
View Article and Find Full Text PDFNew Dirac points may appear when periodic potentials are applied to graphene, and there are many interesting effects near them. Here we investigate the Zitterbewegung effect of fermions described by a Gaussian wave packet in graphene superlattice near these points. The Zitterbewegung near different Dirac points has similar characteristics, while fermions near new ones have different group velocities in both x- and y-direction, which causes the different properties of the Zitterbewegung near them.
View Article and Find Full Text PDFJ Opt Soc Am A Opt Image Sci Vis
August 2018
In this work, a new class of partially coherent Schell-type sources is introduced by modifying its degree of coherence, which is a product of a parabolic function and a Gaussian function. Such sources are confirmed to be physically genuine and may be called parabolic-Gaussian Schell-model (PGSM) sources. The propagating expression of the cross-spectral density function of such PGSM sources is derived in a general linear optical system.
View Article and Find Full Text PDFWe perform a systematic study of the Zitterbewegung effect of fermions, which are described by a Gaussian wave with broken spatial-inversion symmetry in a three-dimensional low-energy Weyl semimetal. Our results show that the motion of fermions near the Weyl points is characterized by rectilinear motion and Zitterbewegung oscillation. The ZB oscillation is affected by the width of the Gaussian wave packet, the position of the Weyl node, and the chirality and anisotropy of the fermions.
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