A well-placed 210Pb-dated sediment core extracted from the distal mud in central continental shelf of East China Sea is used to reconstruct high-resolution atmospheric depositional record polycyclic aromatic hydrocarbons (PAHs), believed be transported mainly past 200 years due Asian Monsoon. Total PAHs (TPAHs), based on 16 USEPA priority PAHs, range 27 1788 132 ng g(-1) 2001. TPAH variation reflects energy usage changes and follows closely historical economic development China. are...

Spectrum widths, one of the three moments measured and displayed by Weather Surveillance Radar-1988 Doppler (WSR-88D), are categorized for various weather conditions showing both expected unexpected results. phenomena classified into seven categories based on radar observations, statistics censored spectrum width fields each obtained. Daytime fair without birds, stratiform rain snow, isolated tornadic storms produce signals that have smallest volumetric median values widths (i.e., < 2 m...

An electrodynamic model is presented in this Letter to describe thresholdless lasers, utilizing the application of photonic time crystals (PTCs). By integrating distinctive physical properties PTCs and employing a comprehensive based on four-level system, feasibility achieving laser operation demonstrated. The proposed comprehensively captures intricate interplay between electromagnetic field PTC medium. takes into account ultrafast periodic variations refractive index PTCs, which arise from...

This paper describes how a series dynamic voltage restorer (DVR), based on the use of Cryo-MOSFET PWM inverter and energy storage system, can be used to protect sensitive power customers from sags/swells. The proposed DVR restores end-user its normal level by rapidly injecting compensating onto line against upstream disturbances. control strategy has adopted concept reference tracking control. A law is derived maintain downstream in pure sinusoidal waveshape with constant amplitude, no...

Abstract Manipulation of electromagnetic (EM) waves is essential for various microwave applications. This research studies the modulation EM by using single-layer plasma arrays consisting discharge tubes. We experimentally investigate transmission spectra and backscattering attenuation characteristics arrays, numerical simulations further reveal mechanism influences arrays. The experimental results show that broadband tunable photonic bandgaps can be achieved in frequency ranges 4–7.5 GHz...

Abstract Contrary to accepted usage, the second central moment of Doppler spectrum is not sum moments individual spectral broadening mechanisms. A rigorous theoretical derivation width observed with short dwell times reveals that cannot strictly be taken for variances associated various mechanisms and an added-term coupling shear turbulence needed. Furthermore, antenna rotation are coupled. The expressions derived herein apply radars fixed or scanning beams.

Abstract A generalized expression is derived for the correlation function of signals backscattered from hydrometeors observed with a vertically pointed radar beam in which particle size distribution, turbulence, and mean wind are not homogeneous. This study extends previous work Fang Doviak by including effects distribution on measured Doppler spectrum. It shows spectrum to be volumetric weighted convolution normalized spectra associated wind, oscillation/wobble, terminal velocity. Without...

The preceding works introduced the leapfrog complying divergence implicit finite-difference time-domain (CDI-FDTD) method, which exhibits high accuracy and unconditional stability. In this study, method is reformulated to simulate general electrically anisotropic dispersive media. auxiliary differential equation (ADE) employed solve equivalent polarization currents, are then integrated into CDI-FDTD method. iterative formulae presented, calculation similar that of traditional Additionally,...

Fast electronic readout for high-channel density scintillator-based systems is needed radiation tracking and imaging in a wide range of applications, including nuclear physics, security nonproliferation. Programmable electronics, like FPGAs ASICs, provide fast way conditioning processing the signal real time. In this paper, we present pulse shape discrimination (PSD) method based on shaping circuit commercially available ASIC, Citiroc1A by CAEN Technologies. We used two different times per...

The laboratory, as a research base for university students, is becoming increasingly important to manage. With the development of technology, intelligent laboratory management systems have become trend. Therefore, how implement fast and accurate system has key issue. To solve these problems, this paper constructs preliminary personnel counting based on improved YOLOv9 target detection algorithm. following work been done in paper: downsampling part ADown improved, convolution module SPD-Conv...

We propose and discuss a simple method to generate broadband optical vortices, utilizing the inherent topological vortex structures of polarization around bound states in continuum supported by photonic crystal slab momentum space induce generation beams. Since proposed structure is composed silicon pillars arranged periodically, it lacks true geometric center. It insensitive position incident light does not require specific alignment process compared traditional spiral phase plates....

As a noninvasive optical method, terahertz time-domain spectroscopy (THz-TDS) has been applied to diagnose the plasma parameters. Previous reports mainly focused on phase and amplitude changes of THz waves induced by plasma, while polarization characteristics were rarely reported. In this paper, in addition electron density transmittance, we further polarimetry (THz-TDP) method rotation angles an argon inductively coupled (ICP). The experiment results theoretical analysis extend ability...

Abstract There is an additional zero mean random variable term that couples wind shear and turbulence in the Doppler radar spectrum width equation. This variable, labeled “coupled term,” has been neglected heretofore literature. Herein, variance of squared ascribed to this coupled determined from data collected with a Weather Surveillance Radar-1988 (WSR-88D) two snowstorms; it can exceed 1 m4 s−4. Thus, be significant contributor must considered when using deduce turbulence.

The application of radar absorbing materials on the surface metal aircraft can effectively reduce cross section (RCS). In this paper, physical optics (PO) method is used to calculate RCS electrically large coated targets. First, we original X29 and with a broadband two-layer coating. addition, backscattered electric field data uncoated are obtained by using PO method, respectively. Finally, two-dimensional Inverse Fourier Transform (IFT) collected taken form Synthetic Aperture Radar (ISAR) image.