Observational Diagnosis of Cloud Phase in the Winter Antarctic Atmosphere for Parameterizations in Climate Models

The cloud phase composition of cold clouds in the Antarctic atmosphere is explored using data from the Moderate Resolution Imaging Spectroradiometer （MODIS） and Cloud-Aerosol Lidar with Orthogonal Polarization （CALIOP） instruments for the period 2000-2006. We used the averaged fraction of liquid-phase clouds out of the total cloud amount at the cloud tops since the value is comparable in the two measurements. MODIS data for the winter months （June, July, and August） reveal liquid cloud fraction out of the total cloud amount significantly decreases with decreasing cloud-top temperature below 0°C. In addition, the CALIOP vertical profiles show that below the ice clouds, low-lying liquid clouds are distributed over ～20% of the area. With increasing latitude, the liquid cloud fraction decreases as a function of the local temperature. The MODIS-observed relation between the cloud-top liquid fraction and cloud-top temperature is then applied to evaluate the cloud phase parameterization in climate models, in which condensed cloud water is repartitioned between liquid water and ice on the basis of the grid point temperature. It is found that models assuming overly high cut-offs （ -40°C） for the separation of ice clouds from mixed-phase clouds may significantly underestimate the liquid cloud fraction in the winter Antarctic atmosphere. Correction of the bias in the liquid cloud fraction would serve to reduce the large uncertainty in cloud radiative effects.

Three dimensional phase field study on the thickness effect of ferroelectric polymer thin film

The electromechanical behavior of poly(vinylidene fluoride-trifluoroethylene)[P(VDF -TrFE)]ferroelectric thin film was investigated using the three dimensional(3D) phase-field method. Various energetic contributions,including elastic,electrostatic,and domain wall energy were taken into account in the variational functional of the phase field model.Evolution of the microscopic domain structures of P(VDF-TrFE) polymer film was simulated.Effects of the in-plane residual stress,the film thickness and externally applied electric bias field on the electromechanical properties of the film were explored.The obtained numerical results showed that the macroscopic responses of the electric hysteresis loops are sensitive to the residual stress and electric bias field.It was also found that thickness has a great effect on the electric hysteresis loops and remanent polarization.

Design of broad angular phase retarders for the complete polarization analysis of extreme ultraviolet radiation

A method of designing broad angular phase retarders in the extreme ultraviolet （EUV） region is presented. The design is based on a standard Levenberg-Marquardt algorithm combined with a common merit function. Using this method, a series of broad angular EUV phase retarders were designed using aperiodic Mo/Si multilayers. At photon energy of 90 eV, broad angular phase retarders with 30°, 60°, and 90° phase retardations have been realized in the angular range of 39°-51°. By analyzing and comparing the performances of the designed broad angular phase retarders, we found that the Mo/Si multilayer with more layers could obtain higher phase retardation in broader angular range when used to design the broad angular phase retarder. Broad angular phase retarders possess lower sensitivity toward changing incident angle compared with the traditional phase retarders designed with transmission periodic multilayers, and can be used for the polarization control of broad angular EUV sources.

THE FEASIBILITIES OF USING THE STATISTICAL,FRACTAL AND SINGULAR PROCESSING OF HOMINAL BLOOD PLASMA PHASE IMAGES DURING THE DIAGNOSTICS AND DIFFERENTIATION OF MAMMARY GLAND PATHOLOGICAL STATES

Performed in this work are complex statistical,fractal and singular analyses of phase properties inherent to birefringence networks of protein crystals consisting of optically-thin layers prepared from blood plasma.Within the framework of a statistical approach,the authors have investigated values and ranges for changes of statistical moments of thefirst to the fourth orders that characterize coordinate distributions for phase shifts between orthogonal components of amplitudes inherent to laser radiation transformed by blood plasma with various pathologies.In the framework of the fractal approach,determined are the dimensions of self-similar coordinate phase distributions as well as features of transformation of logarithmic dependences for power spectra of these distributions for various types of hominal mammary gland pathologies.

Three-dimensional modulations on the states of polarization of light fields

Light fields with spatially structured states of polarization（SoPs） are gathering increasing attention because of their potential applications from optical imaging and micromanipulation to classical and quantum communications. Meanwhile,the concepts within structured light fields have been extended and applied to acoustic, electron, and matter waves. In this article, we review recent developments of the SoP modulation of light fields, especially focusing on three-dimensional（3 D） modulations on the SoPs of light fields. The recent progress and novel implementations based on 3 D spin-dependent separation are discussed. Following the discussions to this physical phenomenon, we then describe recent developments on the vector fields with 3 D structured SoP and intensity distributions, namely, 3 D vector fields. The discussed phenomena inspire us to explore other structured light fields for the expansion of applications in biomedical, information science,quantum optics, and so on.

Design of sign-reversible Berry phase effect in 2D magneto-valley material

Manipulating sign-reversible Berry phase effects is both fundamentally intriguing and practically appealing for searching for exotic topological quantum states.However,the realization of multiple Berry phases in the magneto-valley lattice is rather challenging due to the complex interactions from spin-orbit coupling(SOC),band topology,and magnetic ordering.Here,taking single-layer spin-valley RuCl_(2)as an example,we find that sign-reversible Berry phase transitions from ferrovalley(FV)to half-valley semimetal(HVS)to quantum anomalous valley Hall effect(QAVHE)can be achieved via tuning electronic correlation effect or biaxial strains.Remarkably,QAVHE phase,which combines both the features of quantum anomalous Hall and anomalous Hall valley effect,is introduced by sign-reversible Berry curvature or band inversion of d_(xy)/d_(x^(2)-y^(2))and d_(z^(2))orbitals at only one of the K/K′valleys of single-layer RuCl_(2).And the boundary of QAVHE phase is the HVS state,which can achieve 100%intrinsically valley polarization.Further,a k·p model unveiled the valleycontrollable sign-reversible Berry phase effects.These discoveries establish RuCl_(2)as a promising candidate to explore exotic quantum states at the confluence of nontrivial topology,electronic correlation,and valley degree of freedom.

Combined effect of the transition layer and interfacial coupling on the properties of ferroelectric bilayer film

Within the framework of modified Ginzburg Landau-Devonshire phenomenological theory, a ferroelectric bilayer film with a transition layer within each constituent film and an interfacial coupling between two materials has been studied. Properties including the Curie temperature and the spontaneous polarization of a bilayer film composed of two equally thick ferroelectric constituent films are discussed. The results show that the combined effect of the transition layer and the interracial coupling plays an important role in explaining the interesting behaviour of ferroelectric multilayer structures consisting of two ferroelectrie materials.

基于实虚交替导频的CO-OFDM-OQAM通信系统激光器相位噪声抑制方法

针对偏移正交幅度调制的相干光正交频分复用(CO-OFDM-OQAM)通信系统,本文提出了一种基于实虚交替导频的相位噪声抑制算法。该算法利用激光器相位噪声的性质和固有虚部干扰(IMI)系数的对称性规律设计全新的实虚交替导频,结合线性拟合,能够准确估计每个频域符号的公共相位误差(CPE)。由于是在频域进行补偿,与时域相位噪声抑制算法相比,计算复杂度大幅下降。搭建了有效速率为65 GBits/s的偏振复用CO-OFDM-OQAM系统的数值仿真平台,研究了不同激光器线宽和子载波个数下系统的传输性能,考察了所提方法对相位噪声的抑制效果。获得的结果证实:OSNR固定为25 dB,子载波总数分别为256、512和1024时,误码率达到FEC极限时所需要的线宽分别为801.1、349和138.4 kHz。对于使用16-QAM调制格式、子载波个数为256或512的系统,能较好补偿激光器的相位噪声,而且不会影响功率峰均比。

Theoretical study on phase conjugation in weakly injected vertical-cavity surface-emitting lasers

This paper gives a detailed theoretical investigation on phase conjugation induced by nearly degenerate fourwave mixing in single mode vertical-cavity surface-emitting lasers （VCSELs） with weak optical injection. Considering VCSELs that can work in linearly polarized or elliptically polarized states, it derives the theoretical expression of the conjugated field by small signal analysis based on the vectoral rate equations-the spin-flip model. For linearly polarized state, VCSELs show similar conjugate spectra to edge-emitting semiconductor lasers. For the elliptically polarized state, dichroism and birefringence parameters as well as the spin-flip rate can change the conjugate spectra. Especially, when frequency detuning of the probe and pump waves is between the positive and negative relaxation oscillation frequency, changes are evident. For specific values of parameters, conjugate efficiency between 20 dB to 40 dB are obtained.

Comparative Study on Polarization Spectral Parameters of Fruit in Southern Xinjiang Based on Roujean Model

Based on the study of phase angle and wavelength in pBRDF (Polarized bidirectional reflectance distribution function), roujean model was proposed to describe Orient (Polarization phase angle) quantitatively. The Roujean model was used to quantitatively describe different fruits intensity components (F00) and polarization phase angle (Orient), and the simulation results were analyzed and compared using statistical analysis and comparison methods to realize the prediction from the regular model to the outdoor fruit tree canopy to the canopy of outdoor fruit tree canopy random distribution. The experimental results showed that: 1) when the phase angle of jujube was 52.19°, 66.51° and 88.26°, the R2 and average errors of F00 parameters described by Roujean model are 0.9982, 0.9963, 0.9912 and 3.80%, 4.17%, 6.40%, respectively; and the R2 and average error of Orient parameters described by Roujean model are 0.9056, 0.9223, 0.9260 and 6.23%, 3.32%, 8.05%, respectively;It can be seen that roujean model can quantitatively describe the Orient parameter of jujube;2) When the phase angle of apricot was 70.99°, 71.28° and 67.91°, the R2 and average errors of F00 parameters described by Roujean model is 0.9862, 0.9823, 0.9792 and 3.40%, 4.82%, 5.19%, respectively; And the R2 and average error of Orient parameters described by Roujean model are 0.9382, 0.8947, 0.8849 and 7.19%, 9.28%, 9.47%, respectively. Roujean model can also quantitatively describe the Orient parameter of white apricot. In summary, the Roujean model can provide a good quantitative description of f00 and a good quantitative description of Orient, which in turn can predict the pBRDF parameter for more fruits with different incidence and detection directions. It can correct the influence of angle factor in the nondestructive testing of outdoor fruits.

Multilayer polarization elements and their applications to polarimetric studies in vacuum ultraviolet and soft X-ray regions

Multilayer polarization elements and their applications to polarimetric studies in 20～400 eV region are mainly reviewed. General principle of selecting material combinations to get high linear polarizance multilayers of reflection type is given with practical examples,with periodic or non-periodic layer structures depending on the usage. Transmission type is introduced as linear polarizer and phase shifter. Their applications include polarization diagnosis of laboratory optical systems and synchrotron radiation beamlines of linear and circular polarization,magnetic rotation experiments such as Faraday rotation and magnetic Kerr rotation on magnetic films and multilayers,and ellipsometry to measure optical constants of thin films precisely. Polarization analysis of soft X-ray fluorescence using multilayer-coated grating is also mentioned. Finally this review is summarized with outlook of further developments.

基于自适应联合调制的massive MIMO-OFDM相位噪声消除方案

极化状态是信号的固有属性,具有对相位噪声不敏感的特性,利用极化状态承载信息的极化调制能消除相位噪声。但极化调制需要2根天线发送和接收,在相位噪声功率较小或无相位噪声时,遍历容量性能较差。为解决此问题,提出一种自适应联合调制方案。该方案结合了正交振幅调制(Quadrature Amplitude Modulation,QAM)和极化调制,并通过自适应调整QAM调制和极化调制阶数的方法,提升不同相位噪声功率时的遍历容量。仿真结果表明,该方案的遍历容量性能优于极化调制和QAM调制方案。

Size-Dependent Oxidation-Induced Phase Engineering for MOFs Derivatives Via Spatial Confinement Strategy Toward Enhanced Microwave Absorption

Precisely reducing the size of metal-organic frameworks(MOFs)derivatives is an effective strategy to manipulate their phase engineering owing to size-dependent oxidation;however,the underlying relationship between the size of derivatives and phase engineering has not been clarified so far.Herein,a spatial confined growth strategy is proposed to encapsulate small-size MOFs derivatives into hollow carbon nanocages.It realizes that the hollow cavity shows a significant spatial confinement effect on the size of confined MOFs crystals and subsequently affects the dielectric polarization due to the phase hybridization with tunable coherent interfaces and heterojunctions owing to size-dependent oxidation motion,yielding to satisfied microwave attenuation with an optimal reflection loss of-50.6 d B and effective bandwidth of 6.6 GHz.Meanwhile,the effect of phase hybridization on dielectric polarization is deeply visualized,and the simulated calculation and electron holograms demonstrate that dielectric polarization is shown to be dominant dissipation mechanism in determining microwave absorption.This spatial confined growth strategy provides a versatile methodology for manipulating the size of MOFs derivatives and the understanding of size-dependent oxidation-induced phase hybridization offers a precise inspiration in optimizing dielectric polarization and microwave attenuation in theory.

Research on propagation properties of elastic waves in two-phase anisotropic media

With the development of seismic engineering and seismic exploration of energy, the underground media that westudy are more and more complicated. Conventional anisotropy theory or two-phase isotropy theory is difficult todescribe anisotropic media containing fluid, such as fractures containing gas, shales containing water Based onBlot theory about two-phase anisotropy, with the use of elastic plane wave equations, we get Christoffel equations.We calculate and analyze the effects of frequency on phase velocity, attenuation, amplitude ratio and polarizationdirection of elastic waves of two-phase, transversely isotropic media. Results show that frequency affects slow Pwave the greatest among the four kinds of waves, i.e., fast P wave, slow P wave, fast S wave and slow S wave.Fluid phase amplitude to solid phase amplitude ratio of fast P wave, fast S wave and slow S wave approaches unitfor large dissipation coefficients. Polarization analysis shows that polarization direction of fluid phase displacement is different from, not parallel to or reverse to, that of solid phase displacement in two-phase anisotropic media.

Tight focusing of partially polarized vortex beams by binary phase Fresnel zone plates

Based on vectorial Debye theory, the focusing properties of partially polarized vortex beam by high numerical aperture Fresnel zone plate are investigated. The effects of the numerical apertures of and the phase difference of binary phase Fresnel zone plates, the topological charge of vortex beam and the degree of polarization of incident beam on the intensity distribution and degree of coherence in the focal plane are investigated in detail. It is shown that elliptical light spots and the flat top beam can be obtained by selecting certain parameters. Studies of degree of coherence reveal that the degree of coherence between x and y components of the electric field, which is zero in the source plane, is improved in the focal plane for vortex beam, but it is hardly changed for the nonvortex beam. It is also proved that any two of the three electric field components Ex, Ey and Ez are completely coherent everywhere in the focal region if the incident light beam is linearly polarized.

Phase and direction dependence of photorefraction in a low-frequency strong circular-polarized plane wave

Contrary to the superposition principle, it is well known that photorefraction exists in the vacuum with the presence of a strong static field, a laser field, or a rotational magnetic field. Different from the classical optical crystals, the refractive index also depends on the phase of the strong electromagnetic field. We obtain the phase and direction dependence of the refractive index of a probe wave incident in the strong field of a circular-polarized plane wave by solving the Maxwell equations corrected by the effective Lagrangian. It may provide a valuable theoretical basis to calculate the polarization evolution of waves in the strong electromagnetic circumstances of pulsar or neutron stars.

Polarization and phase control of two-photon absorption in an isotropic molecular system

We theoretically and experimentally study the polarization and phase control of two-photon absorption in an isotropic molecular system. We theoretically show that the two-photon transition probability decreases when the laser polarization changes from linear through elliptical to circular, and the laser polarization does not affect the control efficiency of two-photon transition probability by shaping the spectral phase. These theoretical results are experimentally confirmed in coumarin 480. Furthermore, we propose that the combination of the laser polarization with the spectral phase modulation can further increase the control efficiency of the two-photon absorption.

Corrosion Behavior of Fe-Al-Zn Interphased Dual Phase Steel in Marine Environment

Intercritical heat treatment operation has been in use for the development of Dual Phase Steel (DPS) and has been found to improve the mechanical properties of the steel. In spite of the enhancement a limitation was however observed as to its corrosion susceptibility. In a bid to further enhance the corrosion resistance of the DPS while maintaining its mechanical properties, galvanealing operation was adopted which involving the immersion of the DPS into Al-Zn melt and subsequently subjecting it to annealing operation at 550°C. Weight loss and linear polarization technique were used to measure or evaluate its resistance in 3.5% NaCl (a simulated marine environment). A minimum of 3 samples was used per immersion time. From the result, it was observed that there is a general sharp decrease in the corrosion rate of the GAS as compared to the control sample. The sample immersed and allowed to dwell in the melt for 20 seconds and further annealed with a soaking time of 20 minutes exhibited the highest corrosion resistance. The polarization curve also shows that the substrate was generally passivated, and this is as a result of the Al-Zn/Fe adhesiveness.

Creation of Multiple Subwavelength Focal Spot Segments Using Phase Modulated Radially Polarized Multi Gaussian Beam

Based on the vector diffraction theory, the effect of complex phase filters on intensity distribution of a radially polarized multi Gaussian beam in the focal region of high NA lens is theoretically investigated. It is observed that a properly designed multi belt complex phase filter can generate subwavelength novel focal patterns including splitting of focal spots and generation of multiple focal spot segments such as eight, six and four focal spots along the optical axis are obtained. We expect that such an investigation is useful for optical manipulation and material processing, multiple high refractive index particle trapping technologies.