GLORIA

GEOMAR Library Ocean Research Information Access

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences  (19)
  • 2015-2019  (19)
Material
Publisher
  • Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences  (19)
Language
Years
  • 2015-2019  (19)
Year
  • 1
    In: Acta Physica Sinica, Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences, Vol. 66, No. 24 ( 2017), p. 244209-
    Abstract: Extreme ultra-violet (XUV) light and soft X-ray are widely used to detect the microscopic structure and observe the ultra-fast physical process. It is found that high order harmonic with the frequency as high as that of the waterwindow waves and the pulse duration as short as attosecond can be obtained in the laser-plasma interaction. Due to these features, high order harmonic (HH) is a promising alternative to generating ultra-short XUV light and X-ray. Recently, HHs have been observed in the experiments. However, the frequency spectrum is not complete compared with the results predicted theoretically and numerically. It might relate to the damage of the grating target surface by a long laser repulse. In this article, the effect of target surface roughness on the high order generation (HHG) in the interaction between ultra-intense laser pulse and grating targets is investigated by surface current model and particle-in-cell simulations. We find that both the spatial and spectral domains of harmonics are modulated by the periodical structure of the grating due to the optical interference. The roughness on the surface significantly distorts the modulation effect and leads to different radiation angle and spectral distributions. For the ideal grating, only harmonics satisfying matching condition in a certain direction can be enhanced and the radiation power is restricted in the direction nearly parallel to the target surface. When the surface roughness of the grating target is considered, the matching condition is not valid and the harmonics are scattered into the direction away from the target surface. Comparing with the ideal grating target, most of the harmonic energy is concentrated in the low order harmonics and the intensities of the harmonics decrease rapidly with increasing HH order when surface roughness is considered. The results show good consistence with the phenomena observed in previous experiments and provide the technical reference for exploring the future applications of HHs and HHG.
    Type of Medium: Online Resource
    ISSN: 1000-3290 , 1000-3290
    Language: Unknown
    Publisher: Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences
    Publication Date: 2017
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    In: Acta Physica Sinica, Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences, Vol. 64, No. 8 ( 2015), p. 084202-
    Abstract: In this paper, we design a kind of positive and negative gradient refractive index alternating surface and discuss its physical mechanism by the geometrical optics method and the numerical simulation of electromagnetic field. This structure can control the propagation of electromagnetic waves by adjusting some parameters such as refractive gradient. Under certain parameters, electromagnetic waves from space can be confined mainly in the media all the time, or are released into the space after propagating a certain distance in the media. This structure is polarization-independent and wide-band. It means that this structure can be used as a stealth surface by reducing the scattering cross section. Finally, the characteristics of the structure are verified by the numerical simulation.
    Type of Medium: Online Resource
    ISSN: 1000-3290 , 1000-3290
    Language: Unknown
    Publisher: Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences
    Publication Date: 2015
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    In: Acta Physica Sinica, Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences, Vol. 67, No. 12 ( 2018), p. 126801-
    Abstract: In this article, we review the representative work that has been done by Hong-Jun Gao's group in the past two decades in Institute of Physics, Chinese Academy of Sciences. The work focuses on the construction, properties and applications of low-dimensional atomic/molecular crystals, covering the following 3 aspects. 1) Construction and growth mechanisms of low-dimensional quantum structures. Firstly, we demonstrate the fabrication and growth mechanism of a seahorse shaped fractal pattern in C60-TCNQ multilayer thin films by using the ionized-cluster-beam method. Secondly, by modifying the tip of the scanning tunneling microscope (STM), we clearly resolve the six rest atoms and twelve adatoms on a Si(111)-77 unit cell, showing the highest-resolution STM images of the Si(111)-77 surface. According to this work, we investigate the adsorption and bonding of Ge atoms on Si(111)-77 at low coverages. The configurations and growth behaviors of iron phthalocyanine molecules on Au(111) surface from sub-monolayer to bilayer are also reviewed. Furthermore, we demonstrate that organic molecules bond preferentially to different facets of the Ag(775) substrate under different deposition sequences, molecular lengths, terrace widths, and step heights. This can contribute to the design of non-templated selective functionalization of nanocrystals. 2) Reversible conductance transition and spin on-off in low-dimensional quantum structures and applications in ultrahigh-density information storage. Firstly, we implement reversible, erasable, and rewritable nano-recordings on molecular thin films as a result of conductance transition. Then we demonstrate that the Kondo resonance of iron phthalocyanine molecules on an Au(111) substrate depends strongly on adsorption configuration, and the Kondo resonance of manganese phthalocyanine molecules can reversibly switch ON and OFF via attachment and detachment of single hydrogen atom to the molecule. Moreover, we achieve the site-dependent g factor of a single magnetic molecule with sub-molecular resolution, which shows an inhomogeneous distribution of the g factor within a single molecule. These results open up new routes to realizing ultrahigh-density information storage and controlling local spin properties within a single molecule. 3) Construction, physical properties and applications of graphene and other two-dimensional atomic crystals. We start with the fabrication of a wafer-size, high-quality (almost defect free), single-crystalline graphene on Ru(0001). Then we demonstrate the structure of novel two-dimensional (2D) atomic crystals of mono-element, such as silicene,germanene, hafnene, and antimonene. Last but not least, we present the formation of intrinsically patterned bi-elements 2D materials, PtSe2 and CuSe, which can serve as templates for selective self-assembly of molecules and nanoclusters, as well as dual functionalization for catalysis or other applications. The series of work done in Hong-Jun Gao's group has laid a solid foundation in the research field of low-dimensional quantum structures and their applications.
    Type of Medium: Online Resource
    ISSN: 1000-3290 , 1000-3290
    Language: Unknown
    Publisher: Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences
    Publication Date: 2018
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Online Resource
    Online Resource
    Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences ; 2015
    In:  Acta Physica Sinica Vol. 64, No. 14 ( 2015), p. 147302-
    In: Acta Physica Sinica, Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences, Vol. 64, No. 14 ( 2015), p. 147302-
    Abstract: To achieve the surface plasmon resonance (SPR) mode splitting in infrared wavelength band, and to improve the figure-of-merit (FOM) of grating based SPR sensor, in this article we present a new composite grating structure, which consists of double metal gratings, and study the gas sensing performance. Split modes of SPR in composite metal grating are observed by using the finite difference time domain method. The original structure symmetry is broken and changed with increasing relative displacement between the double gratings, as a result, the resonant modes move to opposite directions. Calculated electric field distribution of the two separate resonant modes displays two different degrees of coupling effect between the double gratings. When the relative displacement is further increased till the double gratings are connected to form a new symmetrical single grating, the separate resonant modes will merge into another single resonant mode. If the refractive index of analyte (na) is in a range 1.01≤na≤1.05 and the relative displacement of double gratings is zero, the wavelength sensitivity based on composite metal grating gas sensor reaches 1207.5 nm/RIU (per refractive index of unit) and the FOM is obtained to be 1290.7, while the relative displacement of the double gratings is 100 nm, for the double split modes the wavelength sensitivities are 1205.0 nm/RIU and 1210.0 nm/RIU, respectively, and the corresponding FOMs are 1295.4 and 762.3. Therefore, the high FOM of the composite grating based on SPR sensor possesses great potential applications in biochemical sensing.
    Type of Medium: Online Resource
    ISSN: 1000-3290 , 1000-3290
    Language: Unknown
    Publisher: Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences
    Publication Date: 2015
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    In: Acta Physica Sinica, Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences, Vol. 65, No. 23 ( 2016), p. 235202-
    Abstract: During cardiac development, the growth, remodeling and morphogenesis of embryonic hearts are closely linked to hemodynamic forces. An understanding of the interaction mechanism between hemodynamic forces and heart development is important for the early diagnosis and treatment of various congenital defects. The myocardial wall strain (MWS) in embryonic heart is a critical parameter for quantifying the mechanical properties of cardiac tissues. Here, we focus on the radial strain which is defined as the change of the myocardial wall thickness. An effective measurement of MWS is conductive to studies of embryonic heart development. Chick embryo is a popular animal model used for studing the cardiac development due to the similarity of cardiac development between the human heart and the chick heart at early developmental stages and its easy access. Although various imaging methods have been proposed, there still remain significant challenges to imaging of early stage chick embryo heart because it is small in size and beats fast. Optical coherence tomography (OCT) is a non-contact three-dimensional imaging modality with high spatial and temporal resolution which has been widely used for imaging the biological tissue. In this paper, we describe a method to measure in vivo MWS of chicken embryonic hearts with a high speed spectral domain OCT(SDOCT) system worked at 1310 nm. We perform four-dimensional (4D) (x, y, z, t) scanning on the outflow tract (OFT) of chick embryonic hearts in a non-gated way. The transient states of the OFT are extracted from the 4D data by using the beating synchronization algorithm. The OFT center line can be achieved by image processing. Assuming that the blood flow is parallel to the center line in the blood vessel, we calculate the Doppler angle of blood flow from the OFT center line. In a certain OFT cross-section, the OFT myocardial wall (inner and external borders) is segmented from the OCT images with a semi-automatic boundary-detection algorithm. Then, the myocardial wall thickness is calculated from the Doppler angle, area and sum of inner and external radii of the segmented myocardial wall. The radial strain is obtained by calculating the myocardial wall thickness variation. Previous methods calculated the myocardial wall thickness by directly subtracting inner and external radii. The measured result may be deteriorated by insufficient resolution of the system since the myocardial wall of OFT is very thin. The present method can solve this problem by calculating the thickness through using the sum of the radii instead of the subtraction. The experimental results on embryonic chick hearts demonstrate that the proposed method can measure the MWS of OFT along arbitrary orientation and it is a useful tool for studying the biomechanical characteristics of embryonic hearts.
    Type of Medium: Online Resource
    ISSN: 1000-3290 , 1000-3290
    Language: Unknown
    Publisher: Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences
    Publication Date: 2016
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    Online Resource
    Online Resource
    Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences ; 2016
    In:  Acta Physica Sinica Vol. 65, No. 13 ( 2016), p. 134301-
    In: Acta Physica Sinica, Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences, Vol. 65, No. 13 ( 2016), p. 134301-
    Abstract: In a shallow water waveguide, the low-frequency acoustic field can be viewed as a sum of normal modes. Warping transform provides an effective tool to filter the normal modes from the received signal of a single hydrophone, which can be used for source ranging and geoacoustic inversion. However, it should be noted that the conventional warping operator h(t) = t2+tr2 is only valid for a signal consisting of reflection dominated modes, where r represents the source range. In a waveguide with a strong thermocline or a surface channel where refracted modes dominate the received sound field, the dispersive characteristics of the waveguide become different and the performance of the warping operator h(t) = t2+tr2 will be significantly degraded. In this paper, the dispersive characteristics and warping transform of the refractive normal modes in a waveguide with a linearly decreased sound speed profile are discussed. The formulae for the horizontal wavenumber, the phase in frequency domain and the instantaneous phase in time domain of the refractive mode are deduced. Based on these formulae, the time warping and frequency warping operators verified by the simulated data are presented. Through time-axis stretching or compression, the time warping operator h(t) =tr-t2, where tr= r/c(h) and c(h) represents the bottom sound speed, can transform the refracted modes into single-tone components of frequencies determined by source range, sound speed gradient of water, bottom sound speed and mode number. The frequency warping operator h(f) = Df3, where D is a constant, can transform the refracted modes into separable impulsive sequences through frequency-axis stretching or compression and the time delay of the impulsive sequences changes linearly with the source range. As the warped modes are separated in time domain or frequency domain, these two operators can be used for filtering the refracted normal modes from the received signal. The theories in this paper are also applicable for refractive modes in the waveguide with a linearly increased sound speed profile or a linear variation of the square of the index of refraction (n2-linear sound speed profile).
    Type of Medium: Online Resource
    ISSN: 1000-3290 , 1000-3290
    Language: Unknown
    Publisher: Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences
    Publication Date: 2016
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    In: Acta Physica Sinica, Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences, Vol. 67, No. 12 ( 2018), p. 127401-
    Abstract: Antiferromagnetic, nematic and superconducting phases have been widely found in iron-based superconductors. The study on their relationships is thus crucial for understanding the low-energy physics and high-temperature superconductivity. The so-called nematic phase represents a spontaneous in-plane rotational symmetry breaking of the electronic states, which results in strong in-plane anisotropic properties. We have developed a uniaxial pressure device, which enables us to obtain nematic susceptibility by studying the resistivity change under uniaxial pressure at low temperature. In this paper, we brief two of our recent researches on nematic fluctuations in iron-based superconductors. The first research shows the presence of a nematic quantum critical point in BaFe2-xNixAs2, which exhibits several characteristics, including the zero mean-field nematic transition temperature x=0.11, broad hump feature in the nematic susceptibility in overdoped samples, strongest nematic susceptibility along the (100) direction at x=0.11, and the divergence of zero-temperature nematic susceptibility at x=0.11 for uniaxial pressure along both the (110) and (100) directions. We further study the nematic susceptibility in many other iron-based superconductors and find that the ordered moment at zero temperature linearly scales with nematic Curie constant, which is obtained from the Curie-Weiss-like temperature dependence of nematic susceptibility in these materials. Accordingly, we propose a universal phase diagram for iron-based superconductors, where superconductivity is achieved by suppressing the long-range antiferromagnetic order in a hypothetical parent compound though the enhancement of nematic fluctuations by doping, including both carrier doping and isovalent doping. Our results suggest that nematic fluctuations play a very important role in both the antiferromagnetism and superconductivity in iron-based superconductors.
    Type of Medium: Online Resource
    ISSN: 1000-3290 , 1000-3290
    Language: Unknown
    Publisher: Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences
    Publication Date: 2018
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    In: Acta Physica Sinica, Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences, Vol. 65, No. 22 ( 2016), p. 223207-
    Abstract: Strong-field photoelectron holography encodes detailed temporal and spatial information about both theelectron and ion dynamics. Here, we review a series of numerical studies of strong-field photoelectron holographyin atoms and molecules by a generalized quantum-trajectory Monte Carlo method. By comparingthe generalized quantum-trajectory Monte Carlo simulationwiththe numerical solution of thetime-dependent Schrdinger equation, we demonstrate that, in the nonadiabatic tunneling regime, pronounced nonadiabatic effects occur which manifest in the energy cutoff of the holographic interference structure. Moreover, we found that a profound ring-like pattern can be observed in the deep tunneling ionization regime. Theappearance of the ring-like interference pattern masks the holographic interference structure. In contrast to the tunneling regime, the long-range Coulomb potential is found to play an essential role in the formation of the photoelectron holography in the nonadiabatic tunneling regime.
    Type of Medium: Online Resource
    ISSN: 1000-3290 , 1000-3290
    Language: Unknown
    Publisher: Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences
    Publication Date: 2016
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 9
    Online Resource
    Online Resource
    Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences ; 2015
    In:  Acta Physica Sinica Vol. 64, No. 2 ( 2015), p. 024215-
    In: Acta Physica Sinica, Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences, Vol. 64, No. 2 ( 2015), p. 024215-
    Abstract: In this paper, the attenuation characteristics of 532 nm laser beam in water under different atmospheric conditions (temperature, humidity, air pressure) are investigated experimentally. Experimental results show that the attenuation coefficient of laser beam in water is significantly influenced by the atmospheric environment. The attenuation coefficient decreases with the increase of air pressure, and increases with the increase of temperature. The maximum value of attenuation coefficient of light appears in the case of high temperature and low air pressure, while the minimum value appears in the high air pressure and low temperature. The maximum attenuation coefficient of laser in water is about three times the minimum value. The mechanisms of these phenomena are discussed. These results are valuable for Brillouin lidar to achieve the remote sensing of ocean.
    Type of Medium: Online Resource
    ISSN: 1000-3290 , 1000-3290
    Language: Unknown
    Publisher: Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences
    Publication Date: 2015
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 10
    In: Acta Physica Sinica, Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences, Vol. 64, No. 22 ( 2015), p. 224201-
    Abstract: Metamaterials, composed of subwavelength building blocks with artificial electric/magnetic response, have attracted the intensive interest due to the unprecedented controllability of electromagnetic (EM) waves and the potential applications. Nonetheless, the resonance of the metallic building block induces a strong loss, severely limiting the performance. Dielectric particle based subwavelength structures provide an alternative choice for the manipulation of EM waves, meanwhile, circumventing the loss problem inevitable for metallic metamaterials, in particular, in optical regime. It is shown that this kind of metamaterial can be used to guide the surface wave with the dielectric particle chain, which is similar to the surface plasmon mediated wave guiding. The structure is also shown to be capable of implementing negative refraction with negligible loss theoretically and experimentally. In addition, the single-layer dielectric rod array can be used to achieve omnidirectional total reflection at subwavelength scale. To further extend the functionality of dielectric based metamaterials and make them more appropriate for integrated optics, a variety of experimentally feasible configurations should be designed. In this work, based on the Mie scattering theory and the multiple scattering theory, we investigate the manipulation of EM waves through a single-layer subwavelength dielectric rod array (SDRA) and particle coupled system. Our results show that by removing the central dielectric rod in the SDRA and at the beam focus, like a vacancy defect, a normal incident transverse electric polarized Gaussian beam is weakly transmitted with an efficiency of less than 12 percent. By further introducing a dielectric rod with optimized parameters on the incident side of the vacancy defect, an enhanced transmitted EM wave with an efficiency of 36 percent is exhibited, nearly triple that with a solely vacancy defect. By adding another identical dielectric rod symmetrically on the outgoing side of the vacancy defect, the transmitted EM field pattern can be clearly tailored due to the dual-particle coupling so that the forward scattering is intensified, similar to the beaming effect, although the total transmittance is not further improved. Interestingly, by use of dual-particle system composed of metallic rods a similar effect can be realized as well near the surface plasmon resonance, adding flexibility to design. It should be pointed out that one-way beam propagation can be possibly achieved by constructing an asymmetric dual-particle coupling system. More importantly, the proposed systems are simple and experimentally realizable, which makes them favorable for the on-chip beam steering, offering a possibility to improve the optical element design of the integration photonic circuit in the terahertz and optical range.
    Type of Medium: Online Resource
    ISSN: 1000-3290 , 1000-3290
    Language: Unknown
    Publisher: Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences
    Publication Date: 2015
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...