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Serum contains rich elemental information, and the elemental analysis of the serum using laser-induced breakdown spectroscopy (LIBS) can help with the diagnosis and treatment of cancer. In this work, serum specimens from breast cancer patients were used as samples, and the elements Mg, Ca, and K were analyzed using LIBS. Silver nanoparticles (Ag NPs) were introduced to enhance spectral emission intensities, and this technique is known as nanoparticle-enhanced LIBS (NELIBS). An Ag NP-coated filter paper (Ag NP paper) substrate was prepared and was compared with silicon and aluminum substrates for NELIBS analysis. The Ag NP paper substrate showed lower spectral intensity variances and better elemental distribution uniformity due to the reduced coffee-ring effect compared with silicon and aluminum substrates. The enhanced effect of the Ag NP paper was optimized by adjusting serum volume and Ag NPs concentration. It was found that Mg, Ca, and K required different optimal conditions for spectral enhancement. The highest enhancement factors (EF) for Mg, Ca, and K were 1.85, 1.76, and 3.10, respectively. The electron temperature (Te) and electron number density (Ne) of NELIBS plasmas were measured using the Boltzmann plot and Stark broadening methods and compared with those of the normal LIBS plasmas. The Te and Ne of the NELIBS and normal LIBS samples were generally comparable with each other. Higher Ag NP concentrations led to lower Te values for NELIBS plasmas. [ABSTRACT FROM AUTHOR]

A Ru-Ni@Cu alloy catalyst with a well-connected two-phase or three-phase contact interface is fabricated as an alternative to a Pt-based catalyst for the hydrogen evolution reaction (HER) in water electrolysis in this study. For optimum bonding and adhesion stability, the alloy particles are grown directly on carbon paper (CP) by the hydrothermal method. The alloy particles are composed of central Cu cores, Ni nests wrapped around Cu core, and small (2.0 nm) Ru nanoparticles embedded at the Ni nests. The Ni surface readily adsorbs water, the high conductivity of Cu increases the electron density of the electrode surface to facilitate water splitting, and the Ru surface adsorbs more H+ ions, thus promoting hydrogen production in the Ru-Ni@Cu alloy. Eventually, despite the use of only 1.0 wt% Ru, the 1% Ru-Ni@Cu/CP electrode exhibits a low overpotential of −0.15 V (η = 246 mV and 87.08 mV dec−1) at 100 mA cm−2 in a 1.0 M KOH electrolyte, similarly to the −0.1 V overpotential of the 100% Pt/CP electrode. The electrode maintains excellent catalytic activity without deterioration for 10 days with a Faraday efficiency of 96.89% (50 h) HER and 3000th LSV cycles. [Display omitted] • Ru-Ni@Cu alloy with three-phase interface grown directly onto CP. • Cu core in the center, Ni nest on the outside, and 2.0 nm-sized Ru particle between Cu and Ni. • Hydrogen production promoted by more H+ ions adsorption on the Ru surface. • A low overpotential of −0.15 V even though only 1.0 wt.-% Ru usage. • Faraday efficiency of 96.89% for 3000 min-HER, without catalytic deactivation for 10 days. [ABSTRACT FROM AUTHOR]

In this paper, we physically modeled passivated ultrathin Cu (In1−xGax) Se2 solar cells with different bandgap grading configurations. Firstly, we have designed the cell architecture according to the fabricated model. The novelty in this work is the modeling of passivated u-CIGS solar cells with different bandgap grading profile configurations in order to achieve high efficiency with a thickness of 500 nm. A significant influence on device performance has been observed while changing absorber doping density, electron affinity, and operating temperature (range of 10–70 °C) for the investigated samples. ZnS has been used as a buffer layer to replace the conventional CdS material in order to improve cell efficiency. The impact of the buffer doping density and electron affinity on u-CIGS cell performance is explored. The simulation results show that a high bandgap at the front and rear sides with an acceptor density of 2 × 1016 provide the best electrical cell parameters: Jsc of 31.53 mA/cm2, Voc of 742.78 mV, FF of 77.50%, η of 18.15%. Our findings can be considered guidelines for new single and/or tandem cell optimization to achieve high efficiency. [ABSTRACT FROM AUTHOR]

This study reports the synthesis of functional graphene quantum dots (GQDs) through the thermal pyrolysis of D-penicillamine (DPA) and citric acid towards water treatment. For the first time, a novel type of highly fluorescent probe for selective Cu2+ detection among 26 types of metal ions which considerably enhance the fluorescence intensity of GQD. Furthermore, the recognition effects can be strengthen addition of amino acids owing to raise the electron density of the system and boos the accumulation profile of the sensing molecules. This simple fluorescent probe was applied for facile metal ions recognition in human urine samples, as well as environmental fluids. The proposed DPA-GQDs supported amino acids respond to Cu2+, Hg2+, and Fe3+, with high sensitivity. The intensity of the fluorescence histogram of this probe significantly diminished in exposure to metal ions such as, Cu(II), Hg(II), and Fe(III). Moreover, in our work, microfluidic paper-based (µPADs) was fabricated through a facile and a cost-effective method. Cu2+ can selectively be recognized by GQD-DPA on the paper-based sensors by naked-eye. The functionalized DPA-GQDs is an excellent alternative to previously reported fluorescent probes for sensing, bio-labeling, and other biological usages in aqueous solution. Its nitrogen and oxygen-rich groups can coordinate with Cu2+ and cause to an apparent fluorescence quenching by the non-radiative electron-transmission. The technique presented in this paper is economical and simple in design, and provides a "mix-and-sense" protocol with no need to chemical- or dye-modifications. Our proposed Cu2+ sensing probe exhibits linear response in the concentrations ranging from 0.001 ppm to 5 ppm, with a lower limit of quantitation (LLOQ) of 0.1 ppm in both environmental fluids, and human urine samples. The enhanced color uniformity, the low instrumental needs of the stamp, and disposability of μPADs enable the application of the suggested paper-based device for the commercial diagnostics biosensor. [Display omitted] • Colorimetric recognition of Cu(II) using GQDs-DPA supported amino acids was done. • An μ PADs was proposed for the colorimetric monitoring of ions. • An innovative naked-eye device for the low-cost identification of toxic heavy metal ions was constructed. [ABSTRACT FROM AUTHOR]

Led by the Institute of Geology and Geophysics, Chinese Academy of Sciences, we have built a brand‐new modular active digital phased array, with all solid‐state transmission and digital receiving incoherent scatter radar (ISR) in Sanya (18.3°N, 109.6°E), a station in low latitude China called Sanya ISR (SYISR) since 2015. The development of SYISR involved the indoor design and development of key components, an outdoor prototype test, and the production and debugging of the entire array. The unique features of SYISR include a single‐channel directly connected T/R unit and antenna, a radar array monitoring and calibration network, environmental adaptability design and open architecture. The entire radar has 4,096 channels and 5,930 modules in total. All the technical indices, mainly including a >2 MW peak power, a 43 dBi antenna gain and a <120 K noise temperature, either meet or are superior to the designed value through an independent evaluation. Waveforms of single pulse, linear frequency modulation, Barker code, long pulse and alternating code have been implemented to meet multiple purposes. Four observational modes for ionospheric experiments, including zenith stare, perpendicular to geomagnetic field, meridian scan, and all sky scan, have been developed. We have implemented time domain decoding, frequency domain decoding, and statistical inversion methods in calculating the autocorrelation function and power spectra in signal processing. The preliminary experimental results on ionospheric parameters, plasma lines, irregularities and hard targets are reasonable and encouraging, which greatly enhances our confidence in achieving our scientific goals in the future. Plain Language Summary: The Earth's ionosphere (∼60–1,000 km above the sea level) is composed of dense plasma, which shows complicated variations versus altitude, geographic location, and solar activity level. When a ground‐based radio wave is transmitted onto these plasmas, it will generate stimulated radiation, with a small portion of them radiating back to the ground. If this backscattered radiation is collected by a ground‐based radar, a variety of ionospheric parameters, including plasma density, temperature, and movement speed, can be derived through a complicated signal processing algorithm. An ionospheric monitoring method called incoherent scatter radar (ISR) was therefore developed. However, since this backscattered radiation is very weak, the ISR should be built with sufficiently large power (usually megawatts) and apertures (usually hundreds of square meters). This leads to the high cost of building an ISR, with only a few having been built in the world thus far. In this paper, we describe a newly built ISR, called Sanya ISR (SYISR), in low latitude China by applying modern radar technologies, such as modular active digital phased arrays, all solid‐state transmitting and digital receiving. The development of SYISR followed the principle of a gradual and orderly progress, including indoor design, outdoor prototype testing and the entire radar construction and debugging. The radar technical indices have been evaluated, and all meet the designed value. We also developed a signal processing algorithm and a variety of observational modes. Finally, preliminary experimental results are shown, which are reasonable and encouraging. In the future, we will gradually achieve our scientific goals via effective data accumulation and analysis. Key Points: Sanya incoherent scatter radar (SYISR) is a newly built incoherent scatter radar in low latitude China with modular active electronic scanning, digital phased array, solid‐state transmitting, and digital receivingThis paper details the hardware, key parameters, data processing and preliminary experimental results of SYISRThe key parameters meet or are superior to the original design, and the preliminary observations are encouraging [ABSTRACT FROM AUTHOR]

PPy/Ag/cellulose paper bar, prepared by making use of capillary forces of cellulose paper for liquids, presents sensitive response to multiple inducement of pH, gas (mist and human breath), and mechanical behavior (finger press). These feedback stems from the variation of bipolaron density and the modulation of electrons transfer efficiency in PPy/Ag/cellulose paper bar. [Display omitted] • Efficient and rapid way to couple cellulose paper with conductive polymer and Ag. • PPy/Ag/cellulose paper bar with flexibility, portability, low cost, lightweight. • Paper with sensitive reply to multiple stimulus of pH, mist, breath, and finger press. Cellulose paper is a flexible, biocompatible and portable substrate that possess high potential in smart sensing and electronic application field. The performance of cellulose paper can be regulated to meet special requirements by assembling it with functional material. In this work, we show an efficient way to couple cellulose paper with Polypyrrole (PPy) and Ag within 5 s, driven by capillary forces of cellulose paper for liquids. The prepared PPy/Ag/cellulose paper bar exhibited sensitive feedback to multiple inducement of pH, gas (mist and human breath), and mechanical behavior (finger press). These response is attributed to the variation of bipolaron density and the modulation of electrons transfer efficiency in PPy/Ag/cellulose paper bar. [ABSTRACT FROM AUTHOR]

The echo traces in the ionograms contain key information about the ionosphere. Therefore, the accurate extraction of these traces is crucial for the subsequent work. This paper transforms the original signal processing problem into a semantic segmentation task, combines it with the currently popular deep learning techniques, and proposes a multiscale Transformer network to achieve pixel-level trace extraction. To train the proposed model, we built a dataset by discretizing the original echo data, labeling, and other preprocessing work. A series of advanced semantic segmentation networks are utilized for comparative experiments. The analysis of the results indicates that the proposed network excels in performance, achieving the highest scores on key semantic segmentation evaluation metrics, including mIoU, Kappa, Dice, and AUC-ROC. In addition, this paper also designs a series of ablation experiments to observe the changes in network performance and to evaluate the rationality of the network design. The experimental results demonstrate the effectiveness of the network in the trace extraction task, which plays a positive role in the subsequent electron density reversal work. [ABSTRACT FROM AUTHOR]

In this paper we make an attempt to study the effect of a nanosecond prepulse on electron acceleration from microscopic solid particles. While standard scaling laws predict temperatures of ∼ 50 keV, our investigations showed an anomalous enhancement ( ∼ 200 keV) in electron temperatures from microscopic solids subjected to intense laser fields. Conventional isotropic expansion of the plasma target as a result of pre-pulse interaction is unable to explain the enhancement, prompting an experimental inquiry into the expansion form. Tentacle-like structures emerging from the spherical plasma are detected as an outcome of the pre-pulse interaction, with the region between the tentacles being targeted by the main laser pulse. We resort to PIC simulations to understand and predict the exact plasma condition that exists in this region. In this paper, we study a series of approximate pre-plasma conditions, particle shapes, and electron densities, examining them for their role in electron acceleration from this extended over-critical plasma target. [ABSTRACT FROM AUTHOR]

Due to the inherent toxicity of cadmium selenide (CdSe)‐based quantum dots (QDs), Cd‐free alternatives are being widely investigated. Indium phosphide (InP) QDs have shown great potential as a replacement for CdSe QDs in display applications. However, the performance of InP‐based quantum dot light emitting diodes (QLEDs) is still far behind that of the CdSe‐based devices. In this study, we wanted to show the effects of different approaches to improve the performance of InP‐based QLED devices. We investigated the effect of magnesium (Mg) doping in ZnO nanoparticles, which is used as an n‐type electron transport layer, in balancing the charge transfer in InP‐based QLED devices. We found that an increasing Mg doping level can broaden the ZnO band gap, shift its energy levels, but most importantly, increase its resistivity; as a result, the electron current density is significantly reduced and the device efficiency is improved. We also investigated the effect of high‐photoluminescence quantum yield emitters and different QLED architectures on the device performance. Through optimizing QD structures and devices, red InP QLEDs with the current efficiencies reaching 11.6 cd/A and green InP QLEDs with the current efficiencies reaching 37.0 cd/A were fabricated. [ABSTRACT FROM AUTHOR]

Self‐aligned coplanar thin‐film transistors (TFTs) with a novel dual channel architecture comprising of low mobility and high mobility oxide semiconductors show high field‐effect mobility of > 50 cm2/Vs with positive threshold voltage of > 0 V and low off‐leakage current of < 1 pA. The TFTs with dual channel allow higher mobility than TFTs with a single high mobility channel because the TFTs with dual channel allow strong electron accumulation due to high electron densities both at the interface between gate insulator and 1st oxide semiconductor and at the hetero‐junction interface between 1st and 2nd oxide semiconductors. [ABSTRACT FROM AUTHOR]

Modeling analysis of underwater pulsed arc discharge can predict the characteristics of plasma channels, providing theoretical guidance for the practical application of underwater pulsed discharge. Due to the complexity of experimental diagnostics for 'kA'-level underwater pulsed discharge, there is currently a lack of precise experimental data to support the initial value selection and result optimization of the modeling. This paper established a plasma channel model for underwater pulsed arc discharge. In conjunction with the Saha ionization equilibrium equation, the model was capable of simulating the current, pressure, temperature, and electron density of the channel after gap breakdown. By utilizing spectroscopic diagnostic data and a multi-objective optimization algorithm, the initial values and key parameters of the model were reasonably determined. The simulation results were in good agreement with the experimental diagnostic results, reasonably representing the trends in electron density and blackbody radiation temperature. Moreover, the model was applicable for reasonably explaining the emission spectral mechanism of the arc channel and shock waves prediction under different discharge conditions. [ABSTRACT FROM AUTHOR]

This paper presents the description of antenna parameters related to its radiation/reception capabilities influenced by the plasma parameters in the environment surrounding the antenna, complementing the existing works on the antenna parameters (e.g., the impedance or currents). The parameters considered are the radiation zones' radiuses (inductive, Fresnel, Fraunhofer), scalloping and directivity; a method of transformation of the air/vacuum-measured radiation/reception pattern to the pattern expected for given plasmatic conditions is also considered. Three different simplified plasma conditions are taken into account (different electron densities: 1.4 × 1012 m−3, 4 × 1011 m−3 and 108 m−3), with varying antenna length (1 m, 10 m, 100 m) and signal propagation mode (classic-ionospheric, whistler and Alfvén). The findings show that the presented antenna parameters and its radiation/reception pattern are heavily dependent on the plasma conditions. These findings can be used to form additional requirements and constraints for the mechanical design of new instrumentation for space weather measurements on board spacecraft (e.g., moving the antennas away from the spacecraft in order not to alter their radiation/reception patterns or not to measure the plasma around the spacecraft) or more accurate data processing from existing space weather satellites, allowing, for example, a more precise triangulation of the signal source or its spectral power regarding the actual performance of the antennas submerged in plasma. [ABSTRACT FROM AUTHOR]

ANCHOR is a novel assimilative model developed at the U.S. Naval Research Laboratory, which was designed for rapid assimilative runs. ANCHOR uses recently developed PyIRI model for the background and for the formation of the background covariance matrix. It only takes a few minutes for ANCHOR to complete the data assimilation (DA) for one day, including data pre‐processing and model set up. ANCHOR extracts ionospheric parameters from radio occultation (RO) and ionosonde data using PyIRI formalism and assimilates them as point measurements into maps of the background parameters using a Kalman Filter approach. This paper introduces the ANCHOR algorithm, discusses its coordinate system and background, explains the background covariance formation, discusses the extraction of the ionospheric parameters from the data and the assimilation process, and, finally, shows the results of the observing system simulation experiment with synthetic data simulated using the SAMI3 model. ANCHOR reduces the root mean square errors in the analysis by more than a half for all of the ionospheric parameters in comparison to the background. Finally, this paper discusses advantages and limitations of the parametrized ionospheric DA, highlighting the avenues for its future improvement. Plain Language Summary: ANCHOR is a novel data assimilation model developed at the U.S. Naval Research Laboratory. It combines estimates of the electron density in the Earth's ionosphere from climatological model with observations, producing a better model representation that matches the data. It extracts ionospheric parameters from radio occultation and ionosonde data and assimilates them as point measurements into the maps of the background parameters using Kalman Filter approach. This paper introduces the ANCHOR algorithm, discusses its coordinate system and background, explains the background covariance formation, discusses the extraction of the ionospheric parameters from the data and the assimilation process, and, finally, shows the results of the observing system simulation experiment. Key Points: Novel approach for rapid ionospheric data assimilation (DA) using anchor pointsGlobal ionospheric DA for plasma density parametersExtraction of the anchor points from the ionospheric data [ABSTRACT FROM AUTHOR]

This paper focuses on the theoretical study of the burning rate of D-T fuel in Z-pinch devices with magneto-inertial confinement. The investigated nuclear fusion process involved fast laser ignition of a mixed D-T fuel contained in a capsule at a temperature of 10 keV, influenced by a strong electromagnetic field. The D-T, D-D, D-3He, 3He-3He, and T-T fusion reactions were employed in the calculations. Based on modern experimental fit data of nuclear fusion reaction rates, the particle and energy balance equations, along with their numerical solutions, were considered, utilizing the ion densities of charged particles such as protons, deuterium, tritium, 3He, and 4He ions. The plasma was in a hot, ultra-dense state, under the quasi-neutrality condition, with initial deuterium and tritium densities of 5 × 10 23 cm−3 and an electron density of 10 × 10 23 cm−3. The ion and electron temperatures were considered equal in this paper. The time dependencies of the ion densities, plasma temperature, energy yield from charged ions and neutrons, fusion power density, and bremsstrahlung radiation loss were investigated. [ABSTRACT FROM AUTHOR]

A new one‐dimensional variational (1D‐Var) retrieval method for ionospheric GNSS radio occultation (GNSS‐RO) measurements is described. The forward model implicit in the retrieval calculates the bending angles produced by a one‐dimensional ionospheric electron density profile, modeled with multiple "Vary‐Chap" layers. It is demonstrated that gradient based minimization techniques can be applied to this retrieval problem. The use of ionospheric bending angles is discussed. This approach circumvents the need for Differential Code Bias (DCB) estimates when using the measurements. This new, general retrieval method is applicable to both standard GNSS‐RO retrieval problems, and the truncated geometry of EUMETSAT's Metop Second Generation (Metop‐SG), which will provide GNSS‐RO measurements up to about 600 km above the surface. The climatological a priori information used in the 1D‐Var is effectively a starting point for the 1D‐Var minimization, rather than a strong constraint on the final solution. In this paper the approach has been tested with 143 COSMIC‐1 measurements. We find that the method converges in 135 of the cases, but around 25 of those have high "cost at convergence" values. In the companion paper (Elvidge et al., 2023), a full statistical analysis of the method, using over 10,000 COSMIC‐2 measurements, has been made. Plain Language Summary: This paper presents a new way of estimating the density of electrons in the ionosphere—the part of the Earth's atmosphere in which atoms are ionized by radiation from the Sun. Radio signals sent between GNSS navigational satellites and receivers in a low orbit around the Earth are delayed, and their paths are bent, by the presence of electrons in the ionosphere. Previous attempts to use these observations to estimate the electron density have been based on the delay of the signals. The new approach outlined in this paper uses the bending incurred by the radio waves instead. Such "bending angles" have been used to infer some properties of the lower atmosphere for many years, and are widely available. We demonstrate that by extending these measurements to greater heights, they can provide useful information about the ionosphere as well. Key Points: A new method of deriving ionospheric electron densities, using the difference between bending angles at two different frequenciesIt is based on a 1D variational retrieval, the solution of which is the best fit to the a priori background and the observationsThe forward model assumes the ionosphere to consist of several idealized "Vary‐Chap" electron density layers [ABSTRACT FROM AUTHOR]