Studies on direct transport of particles not only attribute to understand many processes in the fields of biology, physics, chemistry, etc., but also to provide suitable methods to artificially control particles and micro-devices. In recent decades, direct transport in channels has aroused the interest of an increasing number of researchers. However, the current researches on direct transports in ...
The formation mechanism of network traffic flow and its evolution law are closely related to daily activities of travelers. The current studies indicate that the law of network traffic flow evolution is day-to-day; therefore, using days as the scale unit is an important way to illustrate the evolution of network traffic flow. In previous studies, travelers in the network were tacitly assumed to be...
Target waves usually emit concentric circular waves, whereas spiral waves rotate around a central core (topological defect) region, the two forms of waves are closely related due to the similarity of their spatial structures. Spiral waves can be generated spontaneously in a homogeneous system, while target waves usually cannot be self-sustained in the same system. Therefore, spiral waves can be fo...
Frequency is one of the most important physical quantities of electromagnetic (EM) waves. With the development of terahertz (THz) technology, high-precision measurement of THz frequency is required in THz laser development, wireless communication and ultra fine spectrum measurement. The traditional Fabry-Perot (F-P) interferometry and heterodyne detection method are both difficult to achieve high-...
That the femtosecond laser pulses irradiate metallic materials thereby inducing ultrahigh strain rates, is an important experimental approach to studying the material behavior under extreme conditions. Femtosecond laser-generated shock waves in metal films have rise times of several picoseconds, the corresponding diagnostic technique is required to work with a higher time resolution, which makes t...
The question of how long it takes for a particle to tunnel through a barrier, which was first put forward by MacColl (Phys. Rev. 40 621 (1932)), belongs to the fundamental process of quantum physics and has been the subject of intense debate since then. Many efforts have been devoted to addressing this question about how to define, explain and measure this tunneling time, but widespread controvers...
To explore the dynamic properties of Eu 4f76p1/2ns autoionization process, the autoionization branching ratios of ions and the angular distributions of ejected electrons from the Eu 4f76p1/2ns (n=7, 9) autoionizing states are systematically investigated with the combination of the three-step isolated-core excitation (ICE) and the velocity-map imaging techniques The Eu 4f76sns Rydberg states are po...
ELECTROMAGNETISM, OPTICS, ACOUSTICS, HEAT TRANSFER, CLASSICAL MECHANICS, AND FLUID DYNAMICS
Polarization characteristic is an important feature of electromagnetic (EM) wave. Manipulating polarization state and controlling propagation direction of EM wave by phase-gradient metasurface (PGM) have become a research hotspot in recent years. However, using transmissive PGM for polarization manipulation often suffers a low efficiency. To alleviate this problem, multilayered structure was utili...
Manipulating the propagating direction and polarization state of electromagnetic wave is always fascinating and used in a wide field. One of the approaches to achieving this aim is typically based on steering the propagation phase of wave traveling inside an optical medium, such as dielectric lens. Nevertheless, this approach creates new problems, such as high loss, bulky volume and fabrication di...
Combining three-dimensional (3D) imaging ability of optical coherence tomography (OCT) with movement recognition ability of dynamic scattering technique, label-free 3D OCT angiography can be realized, which has a wide range of applications in basic science research and clinical diagnosis. At no expense of line scanning speed, the scale of capillaries can be detected by improving the sensitivity th...
As is well known, a typical measure of the quality of an optical beam is the M2 parameter, but characterizing the beam quality only by M2 is insufficient. A low value of M2 is generally considered to be equivalent to the single-mode operation with a stable beam. However, even when a large amount of power is contained in high-order modes, the existence of a low value of M2is still possible. Hence, ...
Phychography is an important technique in the quantitative phase imaging research domain, which employs the illuminating probes to scan the specimen in an overlapped requirement, and the reconstruction is conducted by using the ptychographic iterative engine. But the contradiction between the imaging efficiency and quality has become a bottleneck for its wide applications. In this paper, we start ...
A joule-level Nd: YAG nanosecond laser of high repetition frequency and high beam quality is developed for Thomson scattering diagnosis. The laser is designed as a master oscillator power-amplifier system mainly including single longitudinal mode seed, pre-amplifier unit and energy extraction unit. The single-longitudinal-mode Q-switched laser of a high stability is taken as the seed laser of outp...
The 1319 nm lasers have important applications in the fields of optical fiber communication, laser medical treatment and laser color display. The Nd:YAG laser pumped by 808 nm laser diode is an efficient alternative to achieving 1319 nm laser output. In recent years, direct pump technology using 885 nm laser diodes has become more promising due to the dramatically reduced thermal effect and improv...
In recent years, the collisional redistribution of radiation and collision-induced broadening of Rydberg atomic spectral lines by buffer gas perturbation have aroused the renewed interest. Rydberg atoms having a large dipole moment and long lifetime can interact with each other coherently for relatively long time, which makes them a potential candidate for quantum information processing. Besides, ...
Previously reported chalcogenide glass Raman fiber lasers are made of glass compositions such as As2S3 or As2Se3. However, due to the high toxicity of the element arsenic, there is a potential risk in the glass preparation, fiber drawing, and testing processes. Therefore, we need to explore new environmentally friendly chalcogenide glasses that do not contain As for Raman fiber lasers. Studies hav...
Goos-Hnchen shift is a special optical phenomenon. With the development of the nano-optics, Goos-Hnchen shift has become one of the most valuable and hottest issues in optical field. Meanwhile, due to the unique feature of the near-zero-refractive-index material, it has been used in many fields, but the effect of Goos-Hnchen shift has little studied and received less attention. As a result, the pu...
The lattice Boltzmann method (LBM) was proposed as a novel mesoscopic numerical method, and is widely used to simulate complex nonlinear fluid systems. In this paper, we develop a lattice Boltzmann model with amending function and source term to solve a class of initial value problems of the FitzHugh Nagumo systems, which arises in the periodic oscillations of neuronal action potential under const...
PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES
Material response and the launch of laser plasma during the 1064 nm nanosecond laser pulse induced damage to the exit surface of fused silica are investigated. Employing a polarization-based two-frame shadowgraphy setup with ~ 60 fs probing resolution, the transient material responses from the rising part of nanosecond pumping pulse to several hundred nanosecond timescale are captured. Using a she...
CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES
Molecular orientation and stacking mode are commonly considered to have vital influence on the optoelectronic performances of organic semiconductor devices via changing the dynamics of charge carriers transferring among the molecules. Highly ordered and homogeneous stacking would allow a fast band transfer mechanism in the phase domain. Therefore the controls of the molecular orientation and the s...
Platinum metal Ir-Rh alloy presents a promising candidate as future ultra-high-temperature gas turbine material due to its excellent high-temperature properties. In this paper, the mechanical properties of Ir-xRh (x=0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100) alloys with different rhodium content are investigated. Self-consistent, periodic, density functional theory calculations, Perdew-Burke-Ernz...
The thermoelectric material is a kind of new functional material, which can convert industrial waste heat and automobile exhaust into the available electric energy by the interaction of carriers. It is widely used in energy, environment, national defense and other fields. For the research of thermoelectric materials, it is the most important to improve the conversion efficiency now. Due to their u...
CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES
Nowadays, the studies on absorption spectra and conductivities of Ti doped ZnO systems have presented distinctly different experimental results when the atom fraction of impurity increases in a range from 1.04 at% to 1.39 at% To solve this contradiction, all calculations in this paper are carried out by the CASTEP tool in the Materials Studio software based on the first-principals generalized grad...
In this paper, we construct a ferromagnet/semiconductor/ferromagnet parabolic well magnetic tunneling junction with double barriers as research object by inserting another semiconductor as a barrier between ferromagnetic and semiconductor potential wells. On the basis of the quantum coherent transport theory and transfer matrix method, we investigate the spin polarized electron transport and the t...
Hydrogen storage remains one of the main challenges in the implementation of a hydrogen-based energy economy. Among various porous materials, hydrogen storage in covalent-organic frameworks (COFs) has attracted the most significant attention since they were first synthesized due to good stability, large surface area, porosity and extremely low density. Although COFs exhibit promising hydrogen stor...
Bandgap engineering is one of the keys to practical applications of ZnO. Using ternary ZnMeO (Me=Be, Mg, Cd, etc.) alloys to regulate the bandgap of ZnO has been widely studied. Alloying ZnO with CdO to form CdxZn1-xO is an effective way to narrow down the bandgap of ZnO. With its narrower bandgap, CdxZn1-xO is a promising candidate for fabricating optoelectronic devices operable in the UV-visible...
Magnonic crystals with spin waves as information carriers are the magnetic counterparts of photonic and phononic crystals. The studies of spin waves or magnons in magnonic crystals have attracted increasing attention, especially for the characteristics of band gaps. However, most of the previous work has paid attention to the magnonic crystals with simple lattices. In this paper, the model of magn...
High time resolution detecting systems for MeV pulsed radiation are essential for inertial confinement fusion diagnostics. Traditional detection of system time resolution is restricted by cable bandwidth. Based on recording excess carrier dynamics in semiconductors, a new detecting mechanism, called RadOptic, was developed by Lawrence Livermore National Laboratory (LLNL). The variation of intensit...
Using ultraviolet photoemission spectroscopy (UPS), X-ray photoemission spectroscopy (XPS), atomic force microscopy (AFM), and grazing X-ray diffraction measurement(GIXRD), we systematically investigate the correlations of interface energy level structure, film growth and the molecular orientation of 2, 7-dioctyl[1]benzothieno-[3, 2-b][1]benzothiophene (C8-BTBT) on Cu(100). We find that the adsorp...
INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY
Rapid solidification is a typical non-equilibrium phase transition process, and the crystallization rate of liquid metal is larger than 1 cms-1. If the alloy is solidified in this case, the solute segregation is reduced or even eliminated and the solid solubility can be improved significantly. Rapid solidification technique can be used to refine the microstructures of alloys, which provides an eff...
The insulated gate bipolar transistor (IGBT) has developed rapidly as a key power device for medium power application since it was first introduced. It is well known for its relatively low conduction loss and easy gate control. The IGBT is commonly seen in the inductive load application circuit. Due to the large inductive load, the current of the IGBT will stay high until the voltage rises to the ...
Streak cameras applied to inertial confinement fusion research and flashless imaging lidar require large working areas. However, the larger the working area, the bigger the temporal distortion is. And the temporal distortion has a great influence on the detecting precision of the streak camera, resulting in an image distortion on the screen. Yet previous streak camera design work emphasized shorte...
Loop region is necessary structural element of protein molecule, and plays significant roles in protein functioning, e.g., in signaling, ligand recognition. Unlike the well-defined secondary structures (i.e., helix, sheet), however, loop regions vary in structure and some of them are even not able to be measured by ordinary experimental methods. For these reasons, computer-aided prediction of loop...
Online social networks, such as Facebook, Twitter and YouTube, play a vital role in information sharing and diffusion, and recently many dynamics models on social networks have been proposed to model information diffusion. However most models are theoretical, their parameters do not come from realistic data and their validity and reliability have not been evaluated empirically. In the paper we fir...