Multiple Polarization Research Articles

Sentiment Analysis of Chinese Product Reviews Based on Fusion of DUAL-Channel BiLSTM and Self-Attention

Product reviews provide crucial information for both consumers and businesses, offering insights needed before purchasing a product or service. However, existing sentiment analysis methods, especially for Chinese language, struggle to effectively capture contextual information due to the complex semantics, multiple sentiment polarities, and long-term dependencies between words. In this paper, we propose a sentiment classification method based on the BiLSTM algorithm to address these challenges in natural language processing. Self-Attention-CNN BiLSTM (SAC-BiLSTM) leverages dual channels to extract features from both character-level embeddings and word-level embeddings. It combines BiLSTM and Self-Attention mechanisms for feature extraction and weight allocation, aiming to overcome the limitations in mining contextual information. Experiments were conducted on the onlineshopping10cats dataset, which is a standard corpus of e-commerce shopping reviews available in the ChineseNlpCorpus 2018. The experimental results demonstrate the effectiveness of our proposed algorithm, with Recall, Precision, and F1 scores reaching 0.9409, 0.9369, and 0.9404, respectively.

Orbital angular momentum multiplexing holography based on multiple polarization channel metasurface

Abstract As a high-degree-of-freedom approach to manipulate the electromagnetic wave, metasurfaces are widely used in high-capacity information technology. Extensive investigations have explored multiplexing techniques using polarization, incident angle, wavelength, and infinite-dimensional multiplexing through Orbital Angular Momentum (OAM). However, due to the limited spatial resolution and array size of the metasurface, the number of multiplexing channels that can be actually realized is limited. Therefore, research on the combination of OAM multiplexing and polarization degrees of freedom is of great significance. Here, we propose and experimentally demonstrate a metasurface holography multiplexing scheme based on multiple polarization channels combined with OAM. Taking advantage of the orthogonal independence of spin angular momentum and orbital angular momentum, multiple OAM multiplexing holograms are constructed in multiple different spin-polarization channels. Utilizing the well-established compatibility between OAM multiplexing and polarization multiplexing, we successfully integrated two multiplane holograms and 15 OAM multiplexing holograms on a single metasurface. Subsequently, we introduced an optical nested encryption framework designed for parallel communication. This work facilitates high-capacity and high-security holography by employing multiplexing metasurfaces, thereby providing innovative design concepts for optical communication, information encryption, and related domains.

Fast wavefront sensing method based on diffraction basis vectors for tightly focused optical systems.

Recently, phase retrieval techniques have garnered significant attention with their exceptional flexibility. However, their application is limited in optical systems with high numerical aperture due to the disregarded polarization properties of the beam. In this paper, a fast wavefront sensing method for tightly focused systems is proposed. Firstly, a vector diffraction model based on the chirp-Z transform is established to analytically describe the focal spot using the modal coefficients of polynomials and diffraction basis vectors, which accommodating any pixel size and resolution, thereby enabling to break through sampling constraints and remove lateral errors. Additionally, a modified Newton-gradient second-order algorithm is introduced to simultaneously optimize wavefront in multiple polarization directions, without the need for diffraction operators during iterations. Both numerical simulations and error analysis confirm the efficacy and precision of the proposed wavefront sensing method.

In situ growing CNTs/TiO2 heterojunction on MXene sheets for enhanced microwave absorption via multiple electron transfer paths and polarization

The novel two-dimensional Ti3C2Tx material exhibits great potential for microwave absorption owing to its 2D layered graphene-like structure and unique physical properties. However, the limited release of absorbing properties due to the low dielectric loss of Ti3C2Tx and its single loss mechanism pose challenges in meeting the functional requirements for microwave absorbers. Herein, carbon nanotubes (CNTs) were grown on the Ti3C2Tx substrates in a tip growth mode under the catalytic influence of Ni using the in situ induced method. Consequently, Ti3C2Tx/CNTs/TiO2 (TCT) structures were successfully prepared through carbonization conditions. It is worth noting that the composite material TCT-800 exhibits excellent absorption performance. The minimum reflection loss (RLmin) value reaches −44.6 dB when the matching thickness is only 1.4 mm, and the corresponding effective absorption bandwidth (EAB, RL < −10 dB) spans from 11.9 GHz to 15.9 GHz, totaling a range of 4.2 GHz. The excellent electromagnetic wave absorption performance of TCT-800 composites is attributed to the polarization phenomenon of more heterogeneous interfaces constructed by Ti3C2Tx nanosheets, CNTs, and TiO2 nanoparticles. This work provides a strategy for synthesizing Ti3C2Tx-based composites with strong electromagnetic attenuation and wide absorption bandwidth performance.

Emergence of Multiple Hysteresis Cycles and Polarization Plateaus: A Monte Carlo Investigation of Fullerene-Like System

This study uses Monte Carlo simulations to study the emergence of polarization plateaus and hysteresis cycles within fullerene-like systems. To explore the dielectric properties of the system, we also applied the Blume-Capel Ising model, which considered critical, coercive and saturation fields. Temperature, ferrielectric parameter, and crystal field all influenced the system’s behavior. Multi-state memory devices, spintronics, and materials characterization can benefit from the discovery of multiple loops and polarization plateaus.

Hierarchical carbon nanotubes-modified heterogeneous composites derived from melamine-mixed ZIF-67/MXene for broadband microwave absorption

In this paper, carbon nanotubes (CNTs) modified TiO2/C/Co@C composites (TiO2/C/Co@C(CNTs)) with good electromagnetic (EM) wave properties were synthesized originated from ZIF-67/MXene composites supplemented with external carbon source melamine by in situ synthesis and high temperature pyrolysis. The effect of the melamine content on the microstructure, EM parameters, and the microwave absorption (MWA) properties of the TiO2/C/Co@C(CNTs) composites was investigated. The results showed that the in-situ grown CNTs were organically connected to the pyrolyzed ZIF-67/MXene derivatives to form a hybrid network structure. The composites achieve the minimum reflection loss (RLmin) value of −47.52 dB at a thickness of 1.5 mm, the effective absorption bandwidth (EAB) of 5.06 GHz at 1.8 mm with the RLmin value of −41.35 dB, and the RLmin value of −52.43 dB at 6.18 GHz. The excellent EM wave attenuation ability of the TiO2/C/Co@C(CNTs) composites covers nearly the entire frequency band of 2–18 GHz with the RLmin value almost less than −30 dB in the thickness of 1.5–5.0 mm. The unique microstructure, dielectric-magnetic synergistic effect, and multiple interfacial polarization optimize the impedance matching. This word proposes a promising new strategy for constructing highly efficient MOF-derived and MXene-based microwave absorbers.

Electro-assisted reduction of chalcopyrite using acetic acid. The feasibility to use weak and less aggressive acids

This work presents for the first time an electrochemical study of the electro-assisted reduction of chalcopyrite using an organic weak acid. The chalcopyrite reduction was assessed at the microelectrolysis level using different electrochemical and characterization techniques. The voltamperometric and FESEM/EDS results revealed that chalcopyrite can be reduced to bornite at more cathodic potentials than −0.25 V vs SHE. When the acetic acid concentration was increased from 0.5 to 3 M, the chalcopyrite reduction kinetics was favored liberating a higher amount of chalcopyritic iron into the bulk solution. The Tafelarian analysis of the system showed that the exchange current density of the chalcopyrite reduction was increased from 1.72x10-7 to 9.71x10-7 A/mm2 at 0.5 and 3 M acetic acid, respectively. A constant Tafel slope of −0.2 V/dec was found in the range of 0.5–3 M acetic acid, which revealed that the same rate determining step (rds) controlled the chalcopyrite reduction. The calculation of the reaction order confirmed that the formation of monoatomic hydrogen from undissociated acetic acid molecules is the rds.The effect of multiple cathodic polarizations was also evaluated on the solid products formed during the chalcopyrite reduction. The X-ray diffraction analysis revealed the formation of less refractory phases. The effect of agitation was studied in the acetic acid system, the results showed that the chalcopyrite reduction kinetics was considerably increased producing metallic copper.

Multi-stimuli-responsive supramolecular polymer via orthogonal pillararene-based host−guest and π−π interactions

We designed and prepared a supramolecular assembly-induced emission enhancement supramolecular polymer (PyP5⊂S2NH2) via rational combination host−guest and π−π stacking interactions between pyrene-functionalized pillar[5]arene host (PyP5) and the bis(dialkylammonium salt)-based BB type guest (S2NH2). With the increasing concentration of S2NH2 and PyP5, the structures of PyP5⊂S2NH2 transformed from linear to cross-linked networks. Moreover, PyP5⊂S2NH2 can be sensitive to multiple stimuli, including temperature, redox, UV-light, pH, solvent polarity, organometallic compound, and competitive guest. This work paves the way to develop fluorescent supramolecular polymers with multi-stimuli-responsive properties via facilely supramolecular approaches.

Synthesis and microwave absorption performance of heat-treated RF/SiO2 aerogels

The well-designed composite with satisfactory electromagnetic microwave absorption at high temperatures remains a serious challenge. Herein, we fabricated a resorcinol-formaldehyde/silica dioxide composite aerogel (RF/SiO2) with a three-dimensional network structure using sol-gel, atmospheric pressure drying technique as well as heat-treated processes to achieve enhanced microwave absorption capabilities in the low frequency range. The pristine RF/SiO2 aerogel presented a typical micropores structure with a surface area, porous volume, and density of 146.82 m2/g, 62.40%, and 0.28 cm3/g, respectively. Remarkably, the RF/SiO2 aerogel showed an effective absorption bandwidth of 3.56 GHz and a minimum reflection loss value of −46.10 dB at 2.25 mm after being heat-treated at 1500 °C, while the maximum effective absorption bandwidth was 3.60 GHz at 2.30 mm. The intricate three-dimensional networks possessed remarkable impedance matching, multiple attenuation mechanisms, interfacial polarization, and dielectric loss, which were attributed to the exceptional ability to absorb electromagnetic microwaves. It offered a fresh approach to creating adaptable and effective microwave absorption materials in military defense.

TSMPN-PSI: high-performance polarization scattering imaging based on three-stage multi-pipeline networks.

Polarization imaging, which provides multidimensional information beyond traditional intensity imaging, has prominent advantages for complex imaging tasks, particularly in scattering environments. By introducing deep learning (DL) into computational imaging and sensing, polarization scattering imaging (PSI) has obtained impressive progresses, however, it remains a challenging but long-standing puzzle due to the fact that scattering medium can result in significant degradation of the object information. Herein, we explore the relationship between multiple polarization feature learning strategy and the PSI performances, and propose a new multi-polarization driven multi-pipeline (MPDMP) framework to extract rich hierarchical representations from multiple independent polarization feature maps. Based on the MPDMP framework, we introduce a well-designed three-stage multi-pipeline networks (TSMPN) architecture to achieve the PSI, named TSMPN-PSI. The proposed TSMPN-PSI comprises three stages: pre-processing polarization image for de-speckling, multiple polarization feature learning, and target information reconstruction. Furthermore, we establish a real-world polarization scattering imaging system under active light illumination to acquire a dataset of real-life scenarios for training the model. Both qualitative and quantitative experimental results show that the proposed TSMPN-PSI achieves higher generalization performance than other methods on three testing data sets refer to imaging distances, target structures, and target materials and their background materials. We believe that our work presents a new framework for the PSI and paves the way to its pragmatic applications.

Structural engineering of porous biochar loaded with ferromagnetic/anti-ferromagnetic NiCo2O4/CoO for excellent electromagnetic dissipation with flexible and self-cleaning properties

Design of multi-functional microwave absorption materials with strong dissipation ability is a practical approach to address the current issue of electromagnetic radiation pollution. Herein, based on the exchange bias interaction between ferromagnetic and anti-ferromagnetic interfaces, a series of absorbers composed of the porous biochar loaded with ferromagnetic/anti-ferromagnetic NiCo2O4/CoO were successfully prepared via a fairly simple process of one-step calcination. By regulating the calcination temperature, the pore size and porosity of porous carbon, morphology of loaded NPs as well as the electromagnetic response property and impedance matching characteristic in such composites can be modulated. The porous biochar/NiCo2O4/CoO composite prepared under 350 °C possesses a remarkable electromagnetic absorption reflection loss (RL) of –48.41 dB at 9.12 GHz with 2.5 mm thickness, and the effective absorption bandwidth (EAB) of 4.32 GHz with 2.2 mm thickness is located at X band, this is owing to the strong coupling effect of multiple dielectric polarizations, magnetic resonances, and eddy current consumption under matched impedance. In addition, the microwave absorbing patch prepared with this composite exhibits a well-hydrophobic property for self-cleaning function, and the large extensibility with substantial breaking strength endows its practical usage as a flexible absorber.

Soliton polarization dynamics in a fiber laser of zero dispersion.

Polarization properties of a soliton generated in a fiber laser of zero dispersion are investigated. Similar to the solitons generated in a fiber laser of all anomalous dispersion, the polarization ellipse of the soliton rotated during pulse evolution inside the cavity. The number of rotations relies on the cavity averaged birefringence with nonlinear bias. The larger the cavity averaged birefringence is, the bigger the bias is. When the period multiplying of solitons appears, the number of rotations depends on both multiplying periods and the cavity averaged birefringence. Multiple polarization states can be observed at a fixed position in the cavity depending on the multiplying period. When the cavity length is equal to n times of the averaged beat length, the polarization ellipse of the soliton rotates n∗m times at a fixed position, where m is equal to the multiplying period.

Compressible, elastic and 3D porous Ti3C2Tx MXene/RGO/CNCs composite aerogel for electromagnetic wave absorbing

Incorporating compressibility, elasticity, and porous structures into microwave- absorbing materials will facilitate electromagnetic wave absorption (EMA) and improve environmental adaptability for practical applications. Herein, a strategy to prepare Ti3C2Tx MXene/reduced graphene oxide (RGO)/ cellulose nanocrystals (CNCs) aerogels via a directed freezing method to design three-dimensional structures and strengthen the interaction between Ti3C2Tx MXene and RGO lamellae is demonstrated. Oriented structures and the addition of CNCs benefit structural stability while achieving superior absorption performance by forming perfect impedance matching and multiple polarization effects. Interestingly, the prepared MXene/RGO/CNCs (MRC-20) aerogel delivers the prominent EMA performance in reported MXene-based absorbing materials, with a minimal reflection loss (RLmin) of − 72.32 dB at 12.0 GHz corresponding to a matching thickness of 2.56 mm and an effective absorption bandwidth (EAB) of 4.96 GHz at 1.88 mm with an RLmin of − 59.87 GHz. Furthermore, by tuning the content of CNCs, the MRC-20 aerogel exhibits the highest stress (37.2 kPa) at 70% compressive strain and demonstrates the stability of the compression cycle. These intriguing features make the hybrid aerogel stand out among numerous absorbers.

Hyper-Branched Gold Nanoconstructs for Photoacoustic Imaging in the Near-Infrared Optical Window.

In plasmonic nanoconstructs (NCs), fine-tuning interparticle interactions at the subnanoscale offer enhanced electromagnetic and thermal responses in the near-infrared (NIR) wavelength range. Due to tunable electromagnetic and thermal characteristics, NCs can be excellent photoacoustic (PA) imaging contrast agents. However, engineering plasmonic NCs that maximize light absorption efficiency across multiple polarization directions, i.e., exhibiting blackbody absorption behavior, remains challenging. Herein, we present the synthesis, computational simulation, and characterization of hyper-branched gold nanoconstructs (HBGNCs) as a highly efficient PA contrast agent. HBGNCs exhibit remarkable optical properties, including strong NIR absorption, high absorption efficiency across various polarization angles, and superior photostability compared to conventional standard plasmonic NC-based contrast agents such as gold nanorods and gold nanostars. In vitro and in vivo experiments confirm the suitability of HBGNCs for cancer imaging, showcasing their potential as reliable PA contrast agents and addressing the need for enhanced imaging contrast and stability in bioimaging applications.

Generating vector beams by modulating and superimposing multiple polarization modes within a helium-neon resonant cavity

In recent years, vector beams, which have greater control freedom due to their non-uniform spatial polarization distribution, have received extensive attention from scholars. In this paper, we present a straightforward intracavity modulation method by increasing the volume of the gas gain medium inside the cavity to induce multimode oscillation. Subsequently, Brewster windows and a curved-output mirror are used to achieve polarization control and superposition of multiple modes within the cavity to generate stable and controllable vector beams. In addition, the polarization purity of the radial vector beam and the angular vector beam can reach 87.98% and 85.52%, respectively. This work can not only break the understanding of the traditional vector beam generation method and deepen the understanding of laser cavity regulation technology but also play a guiding role in designing compact vector lasers.

Design of rich defects carbon coated MnFe2O4/LaMnO3/LaFeO3 heterostructure nanocomposites for broadband electromagnetic wave absorption

The precise construction of abundant heterointerfaces and defects in manganese ferrite for efficient electromagnetic wave (EMW) absorption is highly appealing, yet remains a grand challenge. Herein, we report a class of carbon-coated MnFe2O4/LaMnO3/LaFeO3 heterostructure nanocomposites with foam-like porous structures for enhancing EMW absorption. The optimized sample (the molar ratio of Mn:Fe:La is 1:2:1) delivers extraordinary absorption performance of the minimum reflection loss reaches −68.25 dB at 4.24 GHz, along with the maximum effective absorption (RL ≤ -10 dB) bandwidth is 12.26 GHz (3.11–15.37 GHz) at a thickness of 3.9 mm. EMW absorption mechanism reveals that the multiple polarizations induced by adjustable heterointerfaces and abundant defects in spinel/perovskite nanocomposites enhance its dielectric loss capacity, resulting in impressive EMW absorption performance. Moreover, the amorphous carbon shell further optimizes impedance matching. This study not only provides a good reference for future preparation of microwave absorbing materials with rich heterogeneous interfaces and defects but also broadens the application of such kinds of carbon-coated spinel/perovskite nanocomposites.

Multifunctional ultralight magnetic CNFs/MXene/Fe3O4 nanodiscs aerogel with superior electromagnetic wave absorption performance

The design of innovative microstructures and the implementation of an appropriate multi-component strategy remain challenging in the development of advanced electromagnetic wave (EMW) absorbing materials. Achieving strong absorption and a wide effective absorption bandwidth while maintaining a thin sample thickness and low filling level is particularly demanding. Herein, a three-dimensional (3D) dielectric cellulose nanofiber (CNF)/Ti3C2Tx MXene carbon aerogel, incorporating magnetic Fe3O4 nanodiscs (NDs), was fabricated using a directional-freezing technique followed by reduction. Surprisingly, the reduction process activates the multifunctional application of aerogel with better elasticity and greatly improved electromagnetic properties, killing two birds with one stone. The structured cellular arrangement and the presence of diverse dielectric/magnetic interfaces contribute to the exceptional absorption capabilities by facilitating optimal impedance matching, enabling multiple polarization modes, and fostering electric/magnetic coupling phenomena. The aerogel exhibits excellent microwave absorption properties, characterized by its ultra-lightweight (3 % of filling ratio and 4.65 mg cm−3 of density), ultra-thin (2.18 mm), ultra-wide frequency band (6.68 GHz) and strong absorption (-56.8 dB). Additionally, the aerogel provides attractive functions such as thermal insulation and great mechanical properties (100 % recovery after 1000 cycles under 50 % strain). This study lays the groundwork for the advancement of microwave-absorbing materials, showcasing their vast potential for multifaceted applications.

Lightweight and flexible Ag-wrapped polyimide aerogel fabrics for electromagnetic interference shielding

Lightweight, flexible and highly effective electromagnetic interference (EMI) shielding fabrics are urgent demanded to protect the human body from harmful electromagnetic radiation. However, the design of fiber microstructures for achieving high-performance EMI shielding still remains significant challenges. Herein, novel EMI shielding fabrics have been designed based on polydopamine-assisted Ag deposition on polyimide (Ag@PI) aerogel fabrics. The Ag@PI aerogel fabric integrates highly conductive Ag and leverages the three-dimensional porous structure of aerogel to facilitate multiple reflections and interface polarization of electromagnetic waves. The Ag@PI aerogel fabrics exhibit ultra-high electromagnetic interference shielding performance of 89.4 dB owing to their unique porous structure, while the Ag@PI fabric without porous structure is only 65.1 dB. The normalized specific shielding effectiveness (SSE) of the Ag@PI aerogel fabrics is up to 812.7 dB cm3 g−1, significantly exceeding that of other EMI shielding textiles reported so far.

A 1-bit electronically reconfigurable beam steerable metasurface reflectarray with multiple polarization manipulations

A 1-bit electronically controlled metasurface reflectarray is presented to achieve beam steering with multiple polarization manipulations. A metsurface unit cell loaded by two PIN diodes is designed. By switching the two PIN diodes between ON and OFF states, the isotropic and anisotropic reflections can be flexibly achieved. For either the isotropic reflection or the anisotropic reflection, the two operation states achieve the reflection coefficients with approximately equal magnitude and 180° out of phase, thus giving rise to the isotropic/anisotropic 1-bit metasurface unit cells. With the 1-bit unit cells, a 12-by-12 metasurface reflectarray is optimally designed and fabricated. Under either y- or x-polarized incident wave illumination, the reflectarray can achieve the co-polarized and cross-polarized beam scanning, respectively, with the peak gains of 20.08 dBi and 17.26 dBi within the scan range of about ±50°. With the right-handed circular polarization (RHCP) excitation, the left-handed circular polarization (LHCP) radiation with the peak gain of 16.98 dBic can be achieved within the scan range of ±50°. Good agreement between the experimental results and the simulation results are observed for 2D beam steering and polarization manipulation capabilities.

3D reconstruction method based on the multi-polarization superposition coding phase pattern of LRR objects.

Conventional research in structured light measurements has utilized light intensity as a channel for information. The polarization of light can be used as an additional channel of information. In this paper, a method based on the superposition of multiple polarization states is proposed to encode structured light. By building a polarization model between the color of light and the polarization states, polarized structured light containing phase information is obtained without rotating the polarizer. It is demonstrated that the method improves the waveform quality of stripes and the accuracy of the 3D reconstruction results when measuring highly reflective objects.