Strong Penetration Ability Research Articles

Research advances on the treatment of hydrofluoric acid burns

Hydrofluoric acid is a highly dangerous and toxic inorganic acid, which is widely used in industrial fields and daily life. The risk of hydrofluoric acid burns is related to hydrofluoric acid mass fraction, duration of exposure to hydrofluoric acid, burn area, burn depth, and burn site, etc. Hydrofluoric acid has strong toxicity and tissue penetration ability. A small area of hydrofluoric acid burns can cause death in a short time. Therefore, improving the understanding of the mechanism of hydrofluoric acid burns and learning how to treat hydrofluoric acid burns in different sites can further improve the cure rate of hydrofluoric acid burns.

Reasearch on scattering characteristics of THz waves from a parabolic plasma-coated 2D metallic cylinder

Terahertz wave detection technology is regarded as an important research direction for solving plasma stealth. In this paper, we mainly study the penetration ability of terahertz waves into the plasma to apply terahertz waves in anti-stealth technology. We are going to build a two-dimensional metallic cylinder of unmagnetized plasma coverage, using Runge–Kutta Exponential Time Differencing-Finite Difference Time Domain method to calculate radar scattering cross-section. The effect of the plasma thickness, collision frequency and other parameters on the scattering characteristics is discussed, the numerical results indicate that terahertz wave has a strong penetration ability for plasma, which can be used to improve radar detection technology to deal with plasma stealth technology.

Multi-Classification of UWB Signal Propagation Channels Based on One-Dimensional Wavelet Packet Analysis and CNN

Due to the strong penetration ability and high transmission rate of ultra-wideband (UWB) signals, UWB technology plays a very significant role in the field of precise indoor positioning. However, the harsh and volatile indoor environment leads to non-line-of-sight (NLOS) propagation and severe attenuation of UWB signals, which may generate significant ranging and positioning errors. To mitigate NLOS effect and improve positioning accuracy, existing methods use ranging information and channel impulse response (CIR) to identify UWB signal propagation channels. However, these NLOS identification methods often require a priori knowledge and suitable thresholds, and most of them only perform a binary classification between LOS and NLOS in a particular scenario. To address these disadvantages, this paper proposes a novel multi-classification method to classify UWB signal propagation channels based on one-dimensional wavelet packet analysis (ODWPA) and convolutional neural network (CNN). This method first decomposes the CIR of known categories into colored coefficients images using a one-dimensional wavelet packet function, then uses these images to train CNNs with different structures, and finally selects CNN model with the best performance to identify the unknown category of UWB signal propagation channels. The experimental results show that the performance of the proposed method is always the best, regardless of the type of experimental scenario, and the identification accuracy is always higher than 90% and up to 100%.

Numerical simulation of liquid jet atomization in subsonic crossflow

To explore the influence of different factors on the atomization pattern and characteristics of the crossflow, the influence of three dimensionless parameters is investigated in this paper, namely Weber number, Oh, and the momentum flux ratio q, on the atomization in subsonic crossflow. The investigations are based on the CLSVOF method and Large Eddy Simulation and developed in conjunction with adaptive mesh refinement techniques. In terms of atomization morphology, three-view drawing of the jet fragmentation morphology and cross-sectional deformation processes under different operating conditions are compared and investigated. In terms of atomization characteristics, the jet penetration depth and spraying distribution curves, as well as the fragmentation position and droplet velocity distribution are analyzed in detail. The results show that there is a pronounced effect for Weber number on the fragmentation pattern and atomization characteristics of liquid jet into a crossflow. As the Weber number increases, the column fragmentation dominated by RT instability gradually changes to surface fragmentation dominated by KH instability. The research also concluded that the momentum flux ratio q is a key element in the penetration depth, which is reflected in the fact that when q is larger, the jet bends less with a stronger penetration ability.

An accurate and reliable positioning methodology for land vehicles in tunnels based on UWB/INS integration

At present, the global navigation satellite system (GNSS) is the most widely used technology in the field of vehicle navigation and positioning. However, due to satellite signal blocking, it can be challenging to obtain precise and reliable vehicle positions in completely GNSS-denied environments. In this paper, a positioning strategy utilizing ultra-wide band (UWB) and a low-cost MEMS inertial navigation system (INS) is proposed, aimed at tracking vehicles in typical GNSS-denied scenarios. UWB tech has potential for high-precision ranging due to its strong penetration ability. However, non-line-of-sight (NLOS) propagation still has a high occurrence in typical traffic scenarios due to the fact that the direct path between the radio transmitter and the radio receiver is obstructed. Therefore, a two-step NLOS error mitigation method is proposed to deal with the abnormal measurements of UWB in tunnels. First, a state-of-the-art probabilistic factor graph model is proposed to estimate the vehicle’s position information based on UWB range measurements instead of excluding the NLOS reception. Then, a residual weighting algorithm is employed during UWB/INS loosely coupled integration to further mitigate the NLOS error. Finally, the performance of the proposed methodology is evaluated through experiments. Experiments conducted in the typical NLOS environment of Nanjing show that the proposed method can achieve higher positioning accuracy when compared with the conventional UWB/INS integration.

Experimental Research on a Pipeline Through-wall Communication System Based on Extremely Low Frequency

The traditional fixed-point operation robot of natural gas pipeline uses cable as the medium to realise the throughwall communication. However, with the increase of working distance, problems such as increasing cable weight or friction force with the pipeline wall will prevent the work from continuing and have a high potential risk. In order to solve this problem, this paper puts forward an overall design of the through-wall communication using the extremely low-frequency (ELF) electromagnetic wave with strong penetration ability. Firstly, a model of the solenoid transmitting coil is established using the Maxwell finite element simulation module to simulate the distribution of the extremely lowfrequency electromagnetic field. Then, the influence of different factors such as environment and medium on magnetic field intensity are analysed. With STM32F405 as the main control chip and AD9959 as the transmitting signal source, the hardware circuit of the communication system is built. At the same time, an experimental test of the ELF communication system is carried out and the experimental results show that the designed through-wall communication system can achieve good communication inside and outside the tube. The communication distance along the radial direction of the tube can reach 140 cm, which can meet the communication needs of fixed-point operation of the robot in the tube.

Facile and Green Synthesis of Highly Fluorescent Carbon Quantum Dots from Water Hyacinth for the Detection of Ferric Iron and Cellular Imaging.

Natural biomass is used for facile synthesis of carbon quantum dots (CQDs) with high fluorescence, owing to its abundance, low cost, and eco-friendliness. In this study, a bottom-up hydrothermal method was used to prepare CQDs from water hyacinth (wh) at a constant temperature of 180 °C for 12 h. The synthesized wh-CQDs had uniform size, amorphous graphite structure, high water solubility (containing multiple hydroxyl and carboxyl groups on the surface), excitation light-dependent characteristics, and high photostability. The results showed that the aqueous solution of CQDs could detect Fe3+ rapidly, sensitively, and highly selectively with a detection limit of 0.084 μM in the linear range of 0–330 μM, which is much lower than the detection limit of 0.77 μM specified by the World Health Organization. More importantly, because the wh-CQDs were synthesized without any additives, they exhibited low toxicity to Klebsiella sp. cells even at high concentrations. Moreover, wh-CQDs emitted bright blue fluorescence in Klebsiella sp. cells, indicating its strong penetrating ability. Correspondingly, the fluorescent cell sorting results also revealed that the proportion of cell internalization reached 41.78%. In this study, wh-CQDs derived from natural biomass were used as high-performance fluorescent probes for Fe3+ detection and Klebsiella sp. imaging. This study is expected to have great significance for the application of biomass carbon spots in the field of cellular imaging and biology.

Material identification of construction machinery based on multisource sensor information fusion

In order to improve the recognition accuracy of construction machinery and equipment and materials in low contrast scenes, a construction machinery material recognition algorithm based on multisource sensor information fusion is proposed. In the paper, the millimeter wave radar is fused with the camera considering its strong penetration ability in rainy and foggy days and dim environments. Firstly, the spatial coordinates of radar and camera are unified by establishing a spatial fusion model of millimeter wave and camera; then the target acquired by millimeter wave is projected onto the image and the detection frame intersection and ratio model is used to generate the region of interest of the camera; finally, the improved YOLOv2 algorithm is used to identify the region of interest, and in the improved idea, the low-level information is first connected with the high-level information in multilayer depth. At the same time, a multiscale feature pyramid network structure is used to achieve recognition of objects of different scales. This model effectively reduces interference from other feature categories while improving the recognition efficiency of the system. The algorithm can effectively improve the recognition accuracy of mechanical materials in low-contrast scenes, as demonstrated by the validation of different scenes.

Study on the Molten Pool Fluid Behavior of PAW-Cable-Type Seven-Wire GMAW Hybrid Welding

Plasma arc welding (PAW)-cable-type seven-wire GMAW (gas metal arc welding) hybrid welding is known as a high-efficiency welding combining plasma arc, GMAW arc and cable-type welding wire. In this study, numerical simulation via Fluent of the molten pool temperature field and flow field and experimental verification were conducted on Q235 thin plate hybrid welding with cable-type wire to explore molten pool fluid behavior. The simulation results show that keyholes form in the molten pool due to the strong penetration ability of a plasma arc and then the evolved pores by the surface tension float out of the molten pool. When the GMAW welding current increases, both the length and width of the weld pool enlarge, the weld reinforcement increases and the flow rate of molten metal in the weld pool also speeds up. While the PAW current increases, the weld pool length also increases and the molten metal in the weld pool significantly flows faster, but the weld reinforcement decreases. When the welding speed increases, the weld pool length and fusion depth decrease, but the reinforcement will first increase and then decrease. The experimental results are in strong agreement with the simulation results. It shows that the numerical analysis model established in this paper is accurate, laying a certain theoretical foundation for the popularization of PAW-cable-type seven-wire GMAW hybrid welding.

Further Advancement of Perovskite Single Crystals.

Halide perovskite (HP) single crystals (SCs) are garnering extensive attention as active materials to substitute polycrystalline counterparts in solar cells, photodiodes, and photodetectors, etc. Nevertheless, the large thickness and defect-rich surface results in severe carrier recombination and becomes the major bottleneck for augmented performance. In this perspective, we are looking forward to explaining in detail why the SCs hardly unleash their engrossing potential and introduce two parallel paths for further advancement. First is the modification of thick SCs by reducing the prepared thickness or surface passivation. Second is the large thickness that is conducive to the sufficient absorption of high-energy rays with strong penetrating ability and is beneficial to the thermoelectric effect due to the ultralow thermal conductivity of HPs. These applications provide a roundabout strategy to exploit freestanding SCs with a large thickness. Herein, direct modification and application of thick SCs are systematically introduced, expecting to give rise to the prosperity of HP SCs.

Design and Experimental Study of Bellows Type Standard Infrasound Generator

Infrasound is widely used in nature and human activities, such as earthquakes, volcanic eruptions, mudslides, nuclear explosions, supersonic flight, weapons targeting, etc. Infrasound has strong penetrating ability, long propagation distance, low attenuation, and is widely used in environmental monitoring, military fields, industrial production and other fields. The monitoring of infrasound sound pressure signal mainly depends on the infrasound sensor, and the accurate measurement of infrasound sound pressure mainly depends on the calibration of the infrasound sensor, and the accurate measurement of the infrasound sensor is the premise and guarantee of the application of the infrasound sensor. In this paper, we propose a bellows type standard infrasound generator solution for the piston leakage problem of the most widely used gas cavity pressure method in the calibration of infrasound sensors, obtain the expression of sound field distribution in the bellows by theoretical derivation, and design a calibration device containing an infrasound sound pressure generator, feedback control and infrasound excitation system, data acquisition conditioning system and laser measurement calculation system. The above device was physically built and experiments were conducted on the bellows type standard infrasound generator, and the infrasound time-domain waveform maps from 0.01Hz to 20Hz were obtained. The experimental results show that the bellows type standard infrasound generator designed in this paper can generate standard infrasound sound pressure signals.

Molecular characteristics of organic matter obtained from biochar by carbon disulfide/acetone synergistic extraction

Environmental context Novel insight into BEOMcc is provided by fractionation and FTICR MS. Sub-fractions of biochar were extracted due to the chemical properties of the organic solvents. BEOMcc has a carbon fixation effect, and so is likely beneficial to the growth of plants and microorganisms. Rationale Since carbon disulfide (CS2) has a strong penetrating ability and acetone (CH3COCH3) can dissolve tiny biochar particles, a mixture of these compounds may efficiently extract organic matter from biochar. The extraction efficacy and structural features of a mixture of CH3COCH3 and CS2 (1:1) were tested in this study. Π–Π interactions between CS2 and CH3COCH3 increase the solubility of organic matter in the extraction process. Methodology We used a mixture of CH3COCH3 and CS2 (1:1) to extract organic matter from soybean straw biochar (BEOMcc) and applied Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) for analysis. Results We found that CS2/CH3COCH3 tended to extract refractory substances, and the resulting extract contained a higher number of heteroatoms than the CS2-extractable fraction (1.34 times). Discussion The H/C ratio of BEOMcc is lower than that of CS2- and CH3COCH3-extractable components. The aromatic component of BEOMcc accounts for 52.47%, which is higher than the contribution to CS2-extractable organic matter of approximately 49.9%. The polycyclic aromatic hydrocarbon component of BEOMcc is beneficial to improving soil stability. The organic matter fraction of BEOMcc has a lower H/C ratio. The C/N ratio of BEOMcc is lower than that of the CS2- and CH3COCH3-extractable components. This result reveals that BEOMcc may provide a significant environmental benefit. The polarity of BEOMcc is between that of CS2- and CH3COCH3-extractable components. Implications for future research In this study, the composition of BEOMcc was assessed at the molecular level, and the extraction method was continuously improved to provide more extraction options for the study of biochar–pollutant interactions. This method can be used to extract organic matter that is difficult to extract by conventional methods, which is more closely bound to the biochar framework. It can provide a technical basis for the in‐depth characterisation and utilisation of biochar organic matter.

Beam splitting characteristics of crystal X-ray Laue diffraction

The beam splitter is an optical element that divides a beam of light into two or more subbeams. It is an essential component in many optical experiments. X-ray has the characteristics of short wavelength and strong penetration ability, making it hard to use the optical elements in the visible-light region. Therefore, it is necessary to develop optical elements suitable for X-rays. The atomic layer spacing of the perfect crystal is of the same order of magnitude as the X-ray wavelength, so the crystal diffraction effect can be used to achieve the X-ray modulation. In this paper, the beam splitting characteristics of Laue crystal are analyzed based on X-ray diffraction dynamics and the influences of crystal absorption and incident light angular divergence on the rocking curves of transmission and diffraction are simulated. The modulation of the crystal diffraction in-plane angle and crystal thickness to Laue diffraction beam-splitting ratio is presented quantitatively. The results show that the kinematical theory of X-ray diffraction is not enough to analyze the beam splitting characteristics of the crystal. It is necessary to consider the interaction between the wave fields in the crystal and use the Pendellӧsung effect in the dynamical theory of X-ray diffraction to explain the change of the crystal beam-splitting ratio quantitatively. The influence of angular divergence and crystal absorption are considered in the simulation. The angular divergence broadens the bandwidth of the diffraction, thereby reducing diffraction intensity. The crystal absorption results in asymmetry and peak shift of the transmission curve and affects the intensity of diffraction and the intensity of transmission beam. The experimental results show that the non-dispersive (+n, –n) configuration can effectively eliminate the influence of angle divergence. The beam-splitting ratio can be adjusted in a small range (±2%) by changing the in-plane angle and adjusted in a wide range (±75%) by changing the crystal thickness, thereby realizing the quantitative modulation of the intensity of transmission and diffraction beam.

Research progress on near-infrared long persistent phosphor materials in biomedical applications.

After excitation is stopped, long persistent phosphor materials (LPPs) can emit light for a long time. The most important feature is that it allows the separation of excitation and emission in time. Therefore, it plays a vital role in various fields such as data storage, information technology, and biomedicine. Owing to the unique mechanism of storage and luminescence, LPPs can avoid the interference of sample autofluorescence, as well as show strong tissue penetration ability, good afterglow performance, and rich spectral information in the near-infrared (NIR) region, which provides a broad prospect for the application of NIR LPPs in the field of biomedicine. In recent years, the development and applications in biomedical fields have been advanced significantly, such as biological imaging, sensing detection, and surgical guidance. In this review, we focus on the synthesis methods and luminescence mechanisms of different types of NIR LPPs, as well as their applications in bioimaging, biosensing detection, and cancer treatment in the field of biomedicine. Finally, future prospects and challenges of NIR LPPs in biomedical applications are also discussed.

UWB Positioning Analysis and Algorithm Research

In order to improve the accuracy of indoor positioning, this paper studied the three-dimensional positioning method based on TDOA and designed the ranging experiment with or without occlusion. The error data were analyzed by many experiments, and the advantages of strong penetration and good anti-interference ability of UWB signal were verified. At the same time, the UWB positioning direct matrix algorithm is optimized, and the least square matrix method is used to process the positioning data to obtain more accurate position coordinates. The experimental results show that the accuracy of the positioning data can be improved by about 25% by using the least square matrix method.

Preparation and Properties of a Kind of Tellurium Bismuthate Mid-infrared Luminescent Composite Glass

The band of infrared luminescence includes atmospheric windows of 1-3μm, 3-5μm, and 8-14μm, covering many important characteristic spectra. Therefore, the luminescent materials in this band are used in biomedical, satellite remote sensing, weapon guidance, industrial processing, Weapon penetration and other fields have broad application prospects. In this paper, the preparation method of doped bismuth telluride composite glass material was studied, and the luminescence properties of infrared luminescent composite glass in the 2.7μm band mid-infrared laser in the matrix material. In this paper, the TeO2-Nb2O5-Bi2O3 glass system was selected as the matrix glass to prepare the tellurate infrared emitting composite glass. The Bi3.20Te0.80O6.40 crystal is a three-dimensional growth method, and the nucleation and growth process of the glass-ceramic is a diffusion mechanism, which belongs to the crystallization behavior mainly controlled by diffusion. Transparent bismuth telluride composite glasses with different doping concentrations of rare earth ions were prepared by a two-step heat treatment method. The infrared luminescent composite glass prepared in this paper has strong penetrating ability to smoke and atmosphere, good transmission confidentiality and low loss, and has important application prospects in radar systems, infrared remote sensing, laser ranging and other fields. The final results of the study show that, by comparing the melting and purity of chemical reagents, it can be seen that the melting time consumed by bismuth oxide is 45 minutes, and a purity of 95.5% can be obtained. The time is shorter, which is conducive to reducing a certain cost.

Hydrogen-Rich 2D Halide Perovskite Scintillators for Fast Neutron Radiography.

A fast neutron has strong penetration ability through dense and bulky objects, which makes it an ideal nondestructive technology for detecting voids, cracks, or other defects inside large equipment. However, the lack of effective fast neutron detection materials limits its application. Perovskites have shown excellent optical properties in many areas, but they are absent from fast neutron detection imaging because they cannot directly absorb fast neutrons and emit luminescence. Here, we demonstrate a hydrogen-rich long-chain organic amine modified two-dimensional (2D) perovskite fast neutron scintillator, Mn-(C18H37NH3)2PbBr4(Mn-STA2PbBr4). Its hydrogen density can reach 9.51 × 1028 m-3, and the photoluminescence quantum yield can reach 58.58%, so it is possible to integrate fast neutron absorption and luminescence into a single compound. More importantly, Mn-STA2PbBr4 can be made into a large-area self-supporting fast neutron scintillator plate with satisfactory spatial resolution (0.5 lp/mm (lp: line pairs)). This strategy provides a simple and promising choice for fast neutron scintillator nondestructive testing.

Nanotechnology-Employed Bacteria-Based Delivery Strategy for Enhanced Anticancer Therapy.

Bacteria and their derivatives (membrane vesicles, MVs) exhibit great advantages for targeting hypoxic tumor cores, strong penetration ability and activating immune responses, holding great potential as auspicious candidates for therapeutic and drug-delivery applications. However, the safety issues and low therapeutic efficiency by single administration still need to be solved. To further optimize their performance and to utilize their natural abilities, scientists have strived to modify bacteria with new moieties on their surface while preserving their advantages. The aim of this review is to give a comprehensive overview of a non-genetic engineering modification strategy that can be used to optimize the bacteria with nanomaterials and the design strategy that can be used to optimize MVs for better targeted therapy. Here, the advantages and disadvantages of these processes and their applicability for the development of bacteria-related delivery system as antitumor therapeutic agents are discussed. The prospect and the challenges of the above targeted delivery system are also proposed.

Layered Double Hydroxide Modified with Deoxycholic and Hyaluronic Acids for Efficient Oral Insulin Absorption.

IntroductionThis study aimed to construct a layered double hydroxide (LDH) nanoparticle delivery system that was modified by deoxycholic acid (DCA) and hyaluronic acid (HA) to increase the bioavailability of oral insulin.MethodsLDH-DCA-HA was synthesized by the hybridization of DCA and HA with LDH. Subsequently, insulin was loaded onto LDH-DCA-HA, resulting in the formation of INS@LDH-DCA-HA. The in vivo and in vitro mechanisms of insulin release, as well as the efficiency of insulin absorption, were analyzed before and after DCA-HA modification.ResultsMTT assay showed that there was satisfactory biocompatibility between LDH-DCA-HA and Caco-2 cells at a concentration below 1000 μg/mL. Flow cytometry analysis revealed that Caco-2 cells absorbed INS@LDH-DCA-HA more readily than insulin. Measurement of transepithelial electrical resistance indicated that INS@LDH-DCA-HA induced the reversible opening of tight cell junctions, thereby facilitating its absorption. This was confirmed via laser confocal microscopy analysis, revealing that a large amount of zonula occludens-1 tight junction (TJ) protein was utilized for the paracellular pathway of nanoparticles. We also measured the blood glucose levels of type I diabetic mice and found that oral INS@LDH-DCA-HA exerted a steady hypoglycemic effect lasting 12 h, with a small range of postprandial blood glucose fluctuation. Immunofluorescence analysis showed that the strong penetration ability of INS@LDH-DCA-HA allowed insulin to enter epithelial cells more readily than free insulin. Finally, immunohistochemical analysis of anti-SLC10A1 protein confirmed that the cholic acid transporter receptor protein played a key role in the functioning of INS@LDH-DCA-HA.ConclusionLDH nanoparticles modified by DCA and HA improved the absorption efficiency of insulin by opening the TJs of cells and interacting with the cholic acid transporter receptor protein.

Mucoadhesive phenylboronic acid conjugated chitosan oligosaccharide-vitamin E copolymer for topical ocular delivery of voriconazole: Synthesis, in vitro/vivo evaluation, and mechanism

Topical eye drops still face challenges of low-drug treatment effects and frequent dosing in ophthalmic applications due to the low preocular retention rate and low transcorneal permeability. Thus, we designed and synthesized a phenylboronic acid conjugated chitosan oligosaccharide-vitamin E copolymer (PBA-CS-VE) for use in mucoadhesive voriconazole (VRC)-loaded nanomicelles for fungal keratitis. In vitro mucin binding and ex vivo eyeball adhesion tests show that the copolymer has strong mucoadhesion. The transportation of coumarin-6 (C6) across a monolayer of HCE-T cells and 3D cell spheroids confirm the strong corneal penetration ability of PBA-CS-VE. The mechanism of promoting corneal penetration was studied in terms of intracellular calcium-ion concentration, cell membrane potential, cell membrane fluidity, and the tight junctions of cells. The pharmacokinetics in the aqueous humor were examined to evaluate the ability of nanomicelles in promoting corneal penetration and prolonging ocular retention. VRC-loaded PBA-CS-VE nanomicelles (PBA-CS-VE-VRC) yielded a very favorable therapeutic effect on a rabbit model of fungal keratitis in vivo as compared to the free drug. Overall, the results indicate that PBA-CS-VE nanomicelles are a mucoadhesive candidate with enhanced transcorneal permeability and prolonged preocular retention for efficient delivery of topical ocular drugs. Statement of significanceAlthough eye drops are widely used in ocular drug delivery, the disadvantages such as short retention time and weak corneal penetrating ability still seriously affect the therapeutic effect of the drug. Therefore, the mucoadhesive carrier seems to be an interesting strategy for ocular drug delivery. Herein, a novel phenylboronic acid conjugated chitosan oligosaccharide-vitamin E copolymer was designed and constructed as mucoadhesive nanomicelles loaded with voriconazole for fungal keratitis. These nanomicelles were able to improve the in vitro mucin binding and to prolong the residence time of the drug on the surface of the eyeball. Moreover, the nanomicelles exhibited an enhanced drug permeability in cell monolayer models and 3D cell culture models. This work provides a promising ocular drug delivery system.