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Postulating that academic papers can positively impact the actual teaching practices of science teachers, this study analysed the process of understanding and utilising academic papers by science teachers to teach scientific creativity in their schools. The 45--hour graduate course of three science teachers was explored to identify the difficulties teachers encountered in trying to understand academic papers and to discover how to solve these difficulties. Second, which aspects should be considered when developing teaching materials for scientific creativity to be used in schools were analysed. A transformation model of an academic paper was proposed to understand this process, and the results were organised accordingly. According to this model, it was emphasized to translate academic papers from a general and abstract state to a local and concrete state. Therefore, the role of science educators as knowledge translators was discussed for more practical and effective use of academic papers in school. This study is expected to contribute to research-based teaching by linking academic research with teaching practice.

The recyclable paper based on photochromic materials not only reduces the pollution in the paper manufacture process, but also reduces the pollution caused by the use of ink, which receives wide attention. In this paper, a series of phosphomolybdic acid–phosphotungstic acid/ZnO/polyvinylpyrrolidone (PMoA-PWA/ZnO/PVP) hybrid films, which had different ratio of PMoA/PWA, was prepared by the ultrasonic composite method. The results indicated that the hybrid film prepared when the ratio of PMoA to PWA was 3 had the best photochromic performance. In this system, ZnO was the photosensitizer, while PMoA/PWA was the chromophore. The photochromic mechanism of the PMoA-PWA/ZnO/PVP hybrid film was based on the photogenerated electron transfer mechanism. ZnO generated photoelectron under the excitation of visible light, then PMoA and PWA obtained the photoelectron and produced photoreduction reaction to generate heteropolyblue. The visible light photochromic paper was prepared by loaded PMoA-PWA/ZnO/PVP hybrid film (A3) on A4 paper. Application tests showed that the prepared paper had extremely stable, excellent and reversible visible light photochromic properties, whether it was printing patterns or words, and could replace ordinary paper to realize the reuse of paper.

This study presents an innovative lateral flow microfluidic paper-based analytical device (μPAD) designed for conducting quantitative paper-based enzyme-linked immunosorbent assays (p-ELISA), seamlessly executing conventional ELISA steps in a paper-based format. The p-ELISA device utilizes a passive fluidic circuit with functional elements such as a multi-bi-material cantilever (B-MaC) assembly, delay channels, and a buffer zone, all enclosed within housing for autonomous, sequential loading of critical reagents onto the detection zone. This novel approach not only demonstrates a rapid assay completion time of under 30 min, but also boasts reduced reagent requirements, minimal equipment needs, and broad applicability across clinical diagnostics and environmental surveillance. Through detailed descriptions of the design, materials, and fabrication methods for the multi-directional flow assay (MDFA), this manuscript highlights the device’s potential for complex biochemical analyses in a user-friendly and versatile format. Analytical performance evaluation, including a limit of detection (LOD) of 8.4 pM for Rabbit IgG, benchmarks the device’s efficacy compared to existing p-ELISA methodologies. This pioneering work lays the groundwork for future advancements in autonomous diagnostics, aiming to enhance global health outcomes through accessible and reliable testing solutions.

We propose a stochastic generative model to represent a directed graph constructed by citations among academic papers, where nodes and directed edges represent papers with discrete publication time and citations respectively. The proposed model assumes that a citation between two papers occurs with a probability based on the type of the citing paper, the importance of cited paper, and the difference between their publication times, like the existing models. We consider the out-degrees of citing paper as its type, because, for example, survey paper cites many papers. We approximate the importance of a cited paper by its in-degrees. In our model, we adopt three functions: a logistic function for illustrating the numbers of papers published in discrete time, an inverse Gaussian probability distribution function to express the aging effect based on the difference between publication times, and an exponential distribution (or a generalized Pareto distribution) for describing the out-degree distribution. We consider that our model is a more reasonable and appropriate stochastic model than other existing models and can perform complete simulations without using original data. In this paper, we first use the Web of Science database and see the features used in our model. By using the proposed model, we can generate simulated graphs and demonstrate that they are similar to the original data concerning the in- and out-degree distributions, and node triangle participation. In addition, we analyze two other citation networks derived from physics papers in the arXiv database and verify the effectiveness of the model., Competing Interests: The authors have declared that no competing interests exist.

A unique triboelectric nanogenerator (TENG) using carbon nanotube (CNT) composite papers is proposed in this work. CNT composite papers can be fabricated easily using a method based on the production of Japanese washi paper. To obtain and evaluate the proposed TENGs, several types of CNT composite papers and aluminum plates were prepared. As the CNT composite paper contained many paper fibers, it was expected to be negatively charged, and the aluminum plate was expected to be positively charged across the triboelectric series. Through various experiments, it was confirmed that CNT composite papers could be used as TENGs. In addition, it was found that when a CNT composite paper was used, it contributed to triboelectricity generation, and the contained CNTs efficiently transferred the generated charge to the electrodes. Furthermore, output voltages approaching a maximum RMS value of 300 mV could be obtained. The results of this study will aid in the practical application of paper-based TENGs in the near future.

To improve the accuracy and efficiency of the aging life prediction and assessment of transformer oil-paper insulation, and to make up for the deficiencies of traditional characterizers, such as 2-furfural, carbon monoxide, and carbon dioxide, a method for the simultaneous determination of methanol, ethanol, $n-\mathbf{propanol}$, and $n$-butanol in oil with a single injection is established by headspace-gas chromatography-mass spectrometry. The measured results show that the determination limits of the four alcohol characterizers can be controlled to $\mathbf{10}\ \mu \mathbf{g}/\mathbf{kg}$ level. Based on this method, the change patterns of the above four alcohols with thermal aging time and degree of polymerization are obtained through thermal aging experimental research. Ethanol, $n$-propanol, and $n$-butanol in oil indicate nearly linear correlations with thermal aging time and degree of polymerization, similar to that of methanol. By analyzing 52 sets of measured data of 500 kV EHV transformers in operation, $n$-butanol is found to have excellent performance, and a new method to evaluate the aging state of oil-paper insulation employing $n$-butanol and methanol is proposed along with the aging attention value model. The measured data of 500 kV EHV transformers in operation indicate that the combination of $n$-butanol and methanol as the preferred characterizers can effectively compensate for the shortcoming of traditional characterizers in the early stages of aging, and the feasibility of the method is verified. Two possible pathways for the generation of $n$-butanol by cellulose cleavage during the aging of oil-paper are proposed from the chemical structure of cellulose.

In this study we compare the titles of scientific letters and those of research papers published in the field of astrophysics in order to identify the possible differences and/or similarities between both genres in terms of several linguistic and extra-linguistic variables (length, lexical density, number of prepositions, number of compound groups, number of authors and number of countries mentioned in the paper bylines). We also carry out a cross-genre and cross-journal analysis of the referred six variables. Our main findings may be summarized as follows: (1) When compared to research paper titles, scientific letter titles are usually shorter, they have a lower lexical density, they include a higher number of prepositions per number of words and a lower number of compound groups per number of words, although they have more up to 4-word compound groups, i.e. the simplest ones. As a consequence, scientific letter titles include less information, which is also less condensed, than research paper titles. (2) The predominance of compound adjectives over compound nouns in the titles of both genres highlights the scientificity of astrophysical discourse. (3) In general terms, our data show a positive correlation between title length and the number of countries mentioned in the bylines for both genres. The positive correlation between title length and number of authors is only met in the case of research papers. In light of these findings, it may be concluded that scientific letters are a clear example of a timeliness and more "immediate" science, whereas research papers are connected to a more timeless and "elaborate" science. It may also be concluded that two different collaboration scenarios are intertwining on the basis of three separate geographic and linguistic publication contexts (Mainland Europe, The United Kingdom and The United States of North America).

This study investigates the impact of zirconium-based KZC series crosslinkers with varying zirconium contents and the polyamine-based crosslinker (PBC) on the properties of coated paper, focusing on key performance metrics such as viscosity, wet rub and pick resistance, dry pick resistance, gloss, brightness, ink set-off, and print mottle. The findings reveal that crosslinkers’ type and concentration significantly influence the coating colors’ viscosity, with PBC demonstrating lower low shear viscosity at lower concentrations. The KZC series showed stable viscosity across a zirconium content range of 7% to 20%, and both crosslinker types enhanced wet rub resistance at higher concentrations. Notably, the KZC series, particularly KZC7, exhibited superior wet pick resistance at increased concentrations, highlighting its effectiveness in enhancing the durability of the coating layer. All crosslinkers maintained excellent dry pick resistance, ensuring robust coating performance. While gloss and brightness were generally unaffected, KZC20, which had the highest zirconium content, slightly reduced these optical properties. Ink set-off tests indicated that the KZC series performed better at lower concentrations, whereas higher concentrations led to increased ink set-off, potentially due to over-crosslinking. Print mottle remained consistent across all crosslinkers, indicating uniform coating quality. Overall, the zirconium-based KZC series significantly enhances wet resistance and maintains high performance across various properties, though it may slightly reduce gloss and brightness and increase ink set-off at higher concentrations. PBC offers a balanced performance profile, emphasizing the need for careful crosslinker type and concentration optimization to achieve the desired coating properties for specific applications. This comprehensive evaluation provides valuable insights for developing and optimizing high-performance coated papers.

We developed new teaching materials, electrical resistors and capacitors, using carbon nanotube (CNT) paper and carbon fibre (CF) paper to foster students' creative thinking, thereby deepening and extending learning. Using a CNT-paper electrical resistor, it is possible to elucidate the dependence of the resistance value on the length and width. The resistance value is proportional to the length and inversely proportional to the width of the paper. In the case of the CF-paper capacitor, it is also possible to clarify the dependence of the capacitance value on the area and the distance between papers. The capacitance value is proportional to the areas of the papers and inversely proportional to the distance between them. Based on the results of our experiments using the new teaching materials, we confirmed that the measured values were in good agreement with the values predicted by theoretical calculations. Using these materials, it becomes possible for students to visually and actively learn about electrical resistance and capacitance through experiments by themselves and in discussion with other students, in contrast to the traditional teaching methods practiced in many schools worldwide. We found that teaching methods using these materials are a useful and easy way to teach the basic concepts of resistance and capacitance with geometric factors in classrooms.

The purpose of this research is to investigate the group velocity of tunable two-dimensional photonic crystals. The first step considers a square lattice consisting of dielectric rods in the liquid crystal background. In the next step, this structure was rotated by 45 degrees and its photonic band structure was investigated. Then, by removing a row of dielectric material (silicon) rods a waveguide is made in the photonic crystal. The waveguide mode and the related group velocity of the waveguide mode were investigated. In the following, the effect of applying an external voltage and changing the refractive index of the background material on the group velocity was studied. Afterward, by applying geometrical changes to the size of waveguide side rods, the effect of mentioned geometrical change on the properties of the waveguide mode and the group velocity was investigated. The calculation results show that the group velocity is reduced and as a result, the group index is increased. The investigations carried out show that quantitatively, by applying an external voltage in the ordinary waveguides, the range of changes in the group index is between 7 and 10, but by applying changes in modified waveguides, this quantity changes in the range of 14 to 27, which can be adjusted by applying an external electric field.

In the present study, the computer simulation has been used to generate the (1+1) and (2+1) surfaces with two types of correlation function Gaussian and correlation function Exponential forms. For this aim, a random number generator is used to generate the surfaces with Gaussian height distribution with zero mean, and their correlation functions were assumed to have Gaussian and exponential formulas. The calculations have been done for isotropic and anisotropic surfaces. For monofractal evaluation of rough surfaces, skewness and kurtosis values have been calculated for these (1+1) and (2+1) dimensional surfaces. Moreover, these values have been analyzed by the behavior of probability distribution of height. Also, the Hurst exponents of surfaces have been evaluated to study the irregularity and jaggedness of produced surfaces. Furthermore, the fractal dimension of these rough surfaces has been obtained to describe the complexity of the irregular fractal surfaces.

All human beings need healthy nutrition to grow, so the lack or excess of low-amount elements causes diseases in humans, for this reason, it is essential to know the presence of elements in food. Arak aluminum production factory is located next to Chogha village, so it is necessary to study the effects of this factory and other industries in the region on its agricultural products. In this study, the content of 11 elements was determined: aluminum, bromine, calcium, chlorine, iron, magnesium, manganese, potassium, sodium, scandium, and zinc in crops as wheat, barley, peas, beans and alfalfa prepared from the village of Chogha in the Arak region by neutron activation analysis, as well as 3 other elements, including arsenic, lead, and cadmium were determined by inductively coupled plasma analysis. Magnesium concentration from 1310 to 3970, manganese from 15.2 to 66.3, sodium from 14.2 to 1490, aluminum from 5.72 to 914, chlorine from 364 to 12000, calcium from 413 to 29600, bromine from 0.23 to 14.50, potassium from 4740 to 14700, iron from 10.1 to 1310.0, scandium from 0.033 to 4.02, zinc from 27.7 to 96.7, arsenic from 0.000 to 0.021, lead from 0.000 to 0.003 and cadmium from 0.00 to 0.02 mg/kg. The results show that the concentration of chlorine, manganese, magnesium, iron, sodium, aluminum, bromine, calcium, scandium, zinc, and lead in alfalfa, the concentration of potassium in pinto beans, the concentration of cadmium in barley, and the concentration of arsenic in wheat are higher than another analyzed sample.

Our knowledge about the origin and transformation mechanisms of the bright points in the solar network has a significant role in understanding the ejection of materials and the transfer of energy into the solar corona. Outside the active region of the Sun (AR), although it is called the Quiet Sun (QS), various types of small-scale bright phenomena constantly occur within the boundary of the super granular cells above the magnetic network. Knowing the bright points is an effective key in considering the solar spicules. In this research, we study the solar transition region bright points and examine their apparent velocities with the local correlation tracking Fourier (FLCT) method. The results illustrate that these points differ in apparent velocity direction and brightness. Their lifetime and average horizontal velocity were estimated at 100 s and 4 kms-1, respectively. Recently, a new group of solar spicules has been observed, those lifetimes are around 100 s, and show a typical horizontal velocity of 3-4 kms-1. According to the analysis of the two-dimensional, apparent velocity of the bright points on the rosettes of the network, these points can be the disk counterpart of the type II spicules. In addition, the analysis of the two-dimensional field of velocities shows rotations that can cause the excitation of Alfvenic pulses.

This study investigated the topological phase transition of InSb and InBi under a non-hydrostatic lattice using density functional theory and the WIEN2K code. The results of examining the band structure of InSb and InBi employing the mBJGGA exchange-correlation potential indicate that InSb is a semiconductor with a small band gap and normal band order at the Γ point. At the same time, InBi is a metal with band inversion at the Brillouin zone center. To transform these compounds into topological semiconductors, the lattice of these compounds is subjected to non-hydrostatic lattice expansion. Non-hydrostatic lattice expansion is applied in two ways. Firstly, the lattice constants are expanded in the ab plane while keeping the lattice constant along the c-axis constant. Then, the lattice constant is expanded along the c-axis while keeping the lattice constant in the ab plane constant. The calculations indicate that under the influence of both types of non-hydrostatic lattice expansion, with the breaking of cubic symmetry, a transition towards topological semiconductors occurs.

This article aims to design and construct a plasma generation device using the surface dielectric barrier discharge method (SDBD) on a laboratory scale to produce a stable and uniform atmospheric pressure plasma layer. For this purpose, a copper electrode with a thickness of 100 microns with a comb- like structure was designed and constructed for this system, and a mica sheet with a thickness of 0.5 mm and dimensions of 10 × 10 cm was built to make the dielectric. According to the experimental data and analytical calculations of the constructed SDBD system in working conditions of 3 kV voltage and 12.5 kHz frequency, the consumption power of this system is calculated at 50 watts. Due to the production of stable and uniform plasma created on the dielectric surface and the measured power consumption, this system will be able to be used in various sciences and industries, including surface processing industries.

Abstract This study identifies important factors for designing an effective biomimetic paper‐based fog harvesting substrate by examining the harvesting properties of different surfaces, including glass, polyethylene, and superhydrophobic paper. In laboratory‐scale fogging tests, the wetting behavior of the substrates is characterized, and the importance of the tilt angle of the respective surface relative to the fog flow is elaborated. Because successful fog harvesting requires both efficient accumulation of water droplets on the surface (by condensation and collision) and sufficient but not excessive roll‐off of the liquid, the amount of water finally collected is clearly related to the pinning effect, which should prevent the smallest droplets from being carried away by the wind but must not lead to full and permanent wetting of the surface. Coalescence is identified as a major phenomenon to improve droplet roll‐off. In this context, superhydrophobic paper indicates to be a more effective water collector than glass or polyethylene, especially when oriented vertically, since it allows the droplets to roll off very efficiently. Finally, the addition of glass particles to the superhydrophobic coating is proposed as a means of enhancing pinning and improving the fog harvesting efficiency.

This work presents a dynamic modeling approach for analyzing the behavior of a bi-material cantilever actuator structure, consisting of a strip of filter paper bonded to a strip of tape. The actuator’s response is induced by a mismatch strain generated upon wetting, leading to the bending of the cantilever. The study delves into a comprehensive exploration of the dynamic deflection characteristics of the bilayer structure. It untangles the intricate connections among the saturation, modulus, hygro-expansion strain, and deflection, while uniquely addressing the challenges stemming from fluid–structure coupling. To solve the coupled fluid–solid differential equations, a combined numerical method is employed. This involves the application of the Highly Simplified Marker and Cell (HSMAC) technique for fluid flow analysis and the Finite Difference Method (FDM) for response deflection computation. In terms of the capillary flow model, the Computational Fluid Dynamics (CFD) simulations closely align with the classical Washburn relationship, depicting the wetted front’s evolution over time. Furthermore, the numerical findings demonstrate that heightened saturation levels trigger an increase in hygro-expansion strain, consequently leading to a rapid rise in response deflection until a static equilibrium is achieved. This phenomenon underscores the pivotal interplay among saturation, hygro-expansion strain, and deflection within the system. Additionally, the actuator’s response sensitivity to material characteristics is highlighted. As the mismatch strain evolving from paper hygro-expansion diminishes, a corresponding reduction in the axial strain causes a decrease in response deflection. The dynamic parameter demonstrates that the deflection response of the bilayer actuator diminishes as dynamic pressure decreases, reaching a minimal level beyond which further changes are negligible. This intricate correlation underscores the device’s responsiveness to specific material traits, offering prospects for precise behavior tuning. The dependence of paper modulus on saturation levels is revealed to significantly influence bilayer actuator deflection. With higher saturation content, the modulus decreases, resulting in amplified deflection. Finally, strong concordance is observed among the present fluidically coupled model, the static model, and empirical data—a testament to the accuracy of the numerical formulation and results presented in this study.

The sustainable use of natural resources is becoming an increasingly important issue today. Stone paper, produced as an alternative to cellulose-based paper from the forest, is rich in minerals and produced without cellulose and water. This study focuses on the behavior of screen-printing ink on two different papers, stone paper and coated sticker paper. Properties such as ink adhesion, rubbing resistance, optical printing ink density, ink consumption, and lightfastness were measured on these surfaces. Solvent- and UV-based inks were used, and printing was carried out on cellulose-based (coated sticker paper) and mineral-based (stone paper) paper layers using three different mesh counts (90, 120, and 140 tpc). The rubbing resistance and lightfastness of the papers were also measured. The present findings revealed that stone paper had the same printability properties as cellulose-based paper. The study concluded that using a 140 tpc mesh with both types of ink results in a high-lightfastness ink layer and lower ink consumption. UV-based inks exhibited high rub resistance across all mesh counts. Additionally, when printing with stone paper, there will be a reduction in ink consumption, thereby achieving cost savings. Based on the present findings, it was concluded that water- and oil-resistant stone paper can be considered an essential alternative in many fields, including the printing industry.

Introduction: We report an investigation on collaboration practices in research papers published in the most prestigious English-medium astrophysics journals. Method: We propose an evaluation method based on three numerical indicators to study and compare, in absolute terms, three different types of collaboration (international, national and local) and authors' mobility on the basis of co-authorship. Analysis: We analysed 300 randomly selected research papers in three different time periods and used the student's t-test to determine whether the paired two-sample differences observed were statistically significant or not. Results: International collaboration is more common than national and local collaboration. International, national and local authors' mobility and intra-national collaboration do not seriously affect the indicators of the principal levels of collaboration. International collaboration and authors' mobility are more relevant for authors publishing in European journals, whereas national and intra-national collaboration and national mobility are more important for authors publishing in US journals. Conclusions: We explain the observed differences and patterns in terms of the specific scope of each journal and the socio-economic and political situation in both geographic contexts (Europe and the USA). Our study provides a global picture of collaboration practices in astrophysics and its possible application to many other sciences and fields would undoubtedly help bring into focus the really big issues for overall research management and policy.

This study was conducted to examine students' performance in paper-based and online-based tests. In the context of the study, students' performances were considered in the General Physics course between 2014 and 2015 and 2018-2019 academic years. The participants of this study are 417 students of Engineering and Science faculties at a public university of Kyrgyz Republic. Students' achievement scores in paper-based and online-based tests were obtained and appropriate statistical analysis methods were employed. According to the results, students' demographic data (i.e. gender, faculty and major) have different effects on their performance, and students performed better in online-based tests compared to paper-based tests. Additionally, the study aimed to analyze instructor perceptions related to testing types that interviews were conducted with 26 instructors of the General Physics course. The majority of the instructors indicated that they experienced difficulties related to the traditional form of evaluation due to the following reasons: lack of time to give personal feedback to each student, lack of time for objective evaluation, and difficulty of evaluation of crowded student groups. Therefore, they indicated the necessity of online test implementation in the context of the General Physics course.

This study investigates the physical, mechanical, and structural characteristics of handmade paper samples derived from cellulose extracted from grass clippings using two distinct methods as follows: (1) alkali treatment and (2) alkali treatment followed by bleaching, coupled with the incorporation of barium sulfate as a mineral filler. Our investigation revealed that the handmade paper samples’ densities, moisture contents, and thicknesses varied within the ranges of 0.436 to 0.549 g/cm3, 5.60 to 2.51%, and 0.41 to 0.50 mm, respectively. The tensile strength and folding endurance of the papers produced through alkali treatment with barium sulfate were notably superior to those produced from bleached pulp and barium sulfate. Our analysis indicates that several critical factors, including paper density, thickness, the crystallinity index, and the microfibrillar structure of cellulose, intricately influence the mechanical and strength properties of the samples. Using Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques, we identified characteristic cellulose bonds and examined cellulose’s crystalline and amorphous phases. Additionally, the crystallinity index of the samples was determined using both the Segal and peak deconvolution methods. Scanning electron microscopy (SEM) micrographs revealed interconnected networks of cellulose fibers with varying thicknesses and lengths, along with incorporated mineral filler within the cellulose fiber structure. Variations in mineral particle retention were attributed to the presence or absence of cellulose microfibrils. These findings contribute to our understanding of the observed strength characteristics of the paper samples and underscore the potential applications of cellulose derived from grass clippings, especially when combined with barium sulfate as a mineral filler in paper production.

This paper addresses the challenges of data sparsity and personalization limitations inherent in current recommendation systems when processing extensive academic paper datasets. To overcome these issues, the present work introduces an innovative recommendation model that integrates the wealth of structured information from knowledge graphs and refines the amalgamation of temporal and relational data. By applying attention mechanisms and neural network technologies, the model thoroughly explores the text characteristics of papers and the evolving patterns of user behaviors. Additionally, the model elevates the accuracy and personalization of recommendations by meticulously examining citation patterns among papers and the networks of author collaboration. The experimental findings show that the present model surpasses baseline models on all evaluation metrics, thereby enhancing the precision and personalization of academic paper recommendations.

Assessments are usually thought of as ways for instructors to get information from students. In this work, we flip this perspective and explore how assessments communicate information to students. Specifically, we consider how assessments may provide information about what faculty and/or researchers think it means to know and do physics, i.e., their epistemologies. Using data from students completing assessment questions during one-on-one think aloud interviews, we explore how assessment features did (or did not) impact student engagement with the assessment problems. We analyze video recordings and transcripts to infer the epistemological framings and resources students use while completing introductory-level physics problems. Students' framings tended to be fairly stable, but when shifts occurred, they were triggered by a shift in epistemological resource, which can be activated by assessment feature. This work extends existing work on epistemological framing into the realm of assessment and allows us to consider the effects of assessments on our students' understanding of physics teaching and learning.

In this study, we carry out a qualitative and quantitative analysis of abbreviations in 300 randomly collected research paper titles published in the most prestigious European and US-based Astrophysics journals written in English. Our main results show that the process of shortening words and groups of words is one of the most characteristic and recurrent features in Astrophysics research paper titling construction. In spite of the convenience of abbreviations as a mechanism for word-formation, some of them may pose certain difficulties of understanding and/or misinterpretation because of their specificity, ambiguity, or overlapping. To overcome these difficulties, we propose a series of options which with no doubt would lead to a better interaction among the different branches of Astrophysics in particular and of science in general and would definitely improve how research is currently performed and communicated.

In this study, we present the design and fabrication of a V-shaped resonator that served as an absorption chamber in a laser spectroscopy system for water stable isotope measurement (2H, 17O, 18O) based on optical feedback cavity-enhanced absorption spectroscopy. In the design of a resonator, its length and the radius of curvature of the mirrors guarantee the optical stability of the system. The resonator mirrors are designed considering the condition of stability and based on the desired mode structure of the resonator output. The V-shaped resonator is designed with two arms of 40 cm and inner diameters of 5 mm making an angle of 1.7°. This resonator has an internal volume of 20 cm3 which provides fast response of laser spectrometer. The high reflectivity of mirrors leads to an effective absorption optical path length of 13 km and a high finesse optical resonator of Ƒ~52،000. These values allow low concentration water vapor isotope analyses and resolution of the absorption spectrum of isotopes for accurate isotope measurements, respectively. Resonator mirrors are designed using Mcleod software to have maximum reflectance at a wavelength of 1.4 micrometers. By making a V-shaped optical resonator for measuring stable isotopes of water and subsequent development for measuring stable isotopes of other elements, the possibility of developing the application of stable isotopes in different areas of research will be provided.

In this work, we study the interaction of femtosecond laser with formaldehyde molecule and investigate the effect of intensity and angle of laser polarization on the high harmonic generation. The calculation is done with time-dependent density functional theory in three-dimensional real space. The effect of the ellipticity parameter and the role of different orbitals of this molecule on the high harmonic spectrum is investigated, so that the contribution of different orbitals of the formaldehyde molecule in this process can be controlled. The maximum intensity and the maximum width of the high harmonic spectrum are obtained for the ellipticity parameter of 0.15. Also, if the large diameter of the ellipse of laser polarization is along the y-axis, the intensity of the harmonic spectrum is increased, and the reason for this process is discussed by analyzing the time evolution of the population of ionized electrons. In the following, the effect of incident laser polarization on the output attosecond pulse polarization and its width is investigated, which is resulted in the generation of an elliptically polarized attosecond pulse.

The shock wave or plasma pulse method was presented for the first time in oil wells to solve the problem of worldwide pressure drop and well production. In this study, the technology of underwater electric wire explosion (UWEWE) has been investigated to generate shock waves by using a sudden discharge of very hot plasma energy at a point and then creating a shock wave. The constructed plasma emitting device consists of two electrodes, a set of high voltage capacitors with a voltage of 5 kV and a capacity of 80 microfarads, an electronic block, a Rogovsky coil installed in the electric discharge circuit, and a relay block. For aluminum wire with a diameter of 400 and 500 mm and a length of 30 mm, with a pulsed current at a discharged voltage of 3.8 kV, the total energy deposition is 400 and 500 J, with the energy conversion efficiency of 68 and 66.3%, respectively, and a maximum power of 168 MW.

In this article, we suggested a three-photon quantum scissor that truncates all multiphoton number states with four or more photons and amplifies the remaining photon number states in a probabilistic way. To this end, by assuming the ideality of all beam splitters and detectors of the proposed scheme, the output state of this quantum scissor and its success probability have been derived analytically. In contrast to the one-photon or two-photon quantum scissor, this setup works perfectly for superpositions of up to three photons. For the input coherent state, our results show that the fidelity between ideal amplification and the amplification obtained by this suggested three-photon quantum scissor is as good as that obtained with a network of six one-photon or two two-photon amplifiers. Moreover, the success probability of this generalized quantum scissor is larger than the success probability of six one-photon amplifiers and is comparable to the success probability of two two-photon amplifiers. Therefore, based on the fact that the resources required by the three-photon amplifier are smaller than those required for a network of one-photon or two-photon amplifiers, this proposed device is much more efficient than several one-photon or two two-photon amplifiers.

Using the first-principles calculations, we have investigated the structural, electronic, and magnetic properties of the two-dimensional Janus MnSX (X= Cl, Br, I) monolayers. The dynamical stability for the 2D Janus monolayers has been confirmed by phonon spectrum calculation. Also, all manganese sulfide halide monolayers show half-metal with 100% spin polarization and a wide half-metallic gap. The noncollinear DFT calculations indicate that the two-dimensional Janus monolayers are ferromagnetically ordered systems and the preferred direction of magnetization lies in-plane of Janus manganese sulfide halide monolayers. The magnetic anisotropy energy increases from MnSCl to MnSI, related to the strong spin-orbit coupling at the I atom and the increased asymmetry between the sulfide and halide planes. The dispersion relation of magnetic excited states is obtained by applying the linear order Holstein–Primakoff transformation to the anisotropic Heisenberg Hamiltonian. We estimated Curie temperature for the monolayers by a self-consistent calculation of magnetization as a function of temperature. Our study presents a new class of 2D magnetic materials for future spintronics and valleytronics.

In this research, graphene oxide was prepared by Hamers' improved method, then, with the electric arc method, silver nanoparticles enter the graphene oxide environment diluted with deionized water, and a colloid of core-shell,silver-silver oxide is prepared. After the samples were prepared, graphene oxide plates containing silver nanoparticles were fixed on them, and samples with the same concentration and volume were placed under ultraviolet radiation for 0, 30, 60, 120, and 240 minutes, respectively. Then, various spectra are prepared from the samples and their linear and non-linear behavior is studied in two experiments, Z-scan and phase spatial modulation. The results of ultraviolet-visible spectroscopy, infrared Fourier transform, and X-ray diffraction show that the resulting solution contains graphene oxide nanoplates and silver oxide nanoparticles. Investigating the nonlinear optical properties of the samples also shows that the nonlinear refractive index of the samples is of the order of , which by ultraviolet radiation to the samples, their nonlinear refractive index changes slightly, and on the other hand, the diffraction pattern with two peaks is observed in the formed structure.

The fields resulting from the brain's neural activities provide essential information in diagnosing and treating brain diseases such as epilepsy, convulsions, and brain tumors. Recording brain magnetic field signals is one of the non-invasive brain functional imaging methods, which usually requires magnetic shielding besides expensive and bulky instruments. Although atomic magnetometers are inherently less sensitive than superconducting quantum interference devices, they are considered the best candidate for measuring bio-magnetic fields due to their low manufacturing cost, small size, and no need for cryogenic equipment. Atomic magnetometers measure the low-strength brain magnetic fields based on detecting Zeeman energy splitting and recording changes in the laser light intensity passing through an alkali vapor cell. To improve the sensitivity of these magnetometers, it is common to remove homogeneous noises in two magnetometer channels. For this purpose, we have presented a gradiometer to suppress unwanted magnetic noises. This gradiometer consists of two atomic magnetometers capable of detecting the field produced by the human brain in an unshielded environment in the presence of the Earth's magnetic field. The gradiometer has a sensitivity of 900 fT⁄√Hz. The designed and built gradiometer is suitable for detecting brain magnetic fields, which can be expanded as a multichannel to record the map of the brain's magnetic field.

The aim is to study nonlinear wave dynamics in solar spicules and jets. The life of jets in the context of Alfven wave dynamics is focused. Here, further insight into the solar atmospheric effects together with initial conditions on the dynamics of Alfven waves along with the characteristic parameters of the spicule or jet itself are provided. Results are based on the theory of magnetohydrodynamics. the location of shock formation by the interplay of the internal and external plasma-beta conditions together with the initial steady flow speeds which are rooted in the initiation location of the solar jet are illustrated. It was known that the plasma-beta of a solar jet affects the shock formation time of torsional Alfven waves. However, its efficiency is shown to be dependent on the external plasma beta conditions. The shock formation time for plasma-beta conditions over unity is directly proportional to the plasma-beta, similar to plasma-beta conditions equal to or below unity. In the case where the plasma-beta inside the magnetic structure is small, the shock formation time is accelerated by increasing the external plasma-beta. In photospheric conditions, as for coronal conditions, the time of shock formation is inversely proportional to the external plasma-beta. When the internal plasma-beta is fixed, for various steady flow speeds, the external plasma-beta accelerates the formation of shocks. These results help us to better understand the role of Alfven waves in solar jets in the transfer of energy to the solar system.

Compounds was born in 2021 as an interdisciplinary journal with a clear vocation towards the scientific community and a tool to present its scientific achievements in an open access format that would allow a rapid and efficient dissemination of its scientific results in the field of chemistry [...]

The research results and evaluation of the applicability of the original composition of hybrid paper based on silver nanowires (AgNWs), cellulose pulp (CP), and carbon nanotubes (CNTs) are presented and discussed. The material tested was used to manufacture sensors for mechanical deformation resulting from external influences or related to human activity interactions. The sensors were fabricated using an AgNWs + CP suspension and additives by the vacuum filtration method. The substrate obtained was machined and then laminated with a layer of poly(dimethylsiloxane) (PDMS). The recorded responses to selected types of imposed mechanical interactions in the form of changes in the relative resistance of the sensor throughout the tests showed a close cause-and-effect relationship. The response of the tested systems when applying an alternating magnetic field was also observed. The results indicate that the proposed solutions can find application in the monitoring of mechanical interactions resulting from the dynamic behavior of physical objects, as well as derived from selected human vital functions.

Abstract Paper, an inexpensive material with natural biocompatibility, non‐toxicity, and biodegradability, allows for affordable and cost‐effective substrates for unconventional advanced electronics, often called papertronics. On the other hand, polymeric elastomers have shown to be an excellent success for substrates of soft bioelectronics, providing stretchability in skin wearable technology for continuous sensing applications. Although both materials hold their unique advantageous characteristics, merging both material properties into a single electronic substrate reimagines paper‐based bioelectronics for wearable and patchable applications in biosensing, energy generation and storage, soft actuators, and more. Here, a breathable, light‐weighted, biocompatible engineered stretchable paper is reported via coaxial nonwoven microfibers for unconventional bioelectronic substrates. The stretchable papers allow intimate bioconformability without adhesive through coaxial electrospinning of a cellulose acetate polymer (sheath) and a silicone elastomer (core). The fabricated cellulose‐silicone fibers exhibit a greater percent strain than commercially available paper while retaining hydrophilicity, biocompatibility, combustibility, disposable, and other natural characteristics of paper. Moreover, the nonwoven stretchable cellulose‐silicone fibrous mat can adapt conventional printing and fabrication process for paper‐based electronics, an essential aspect of advanced bioelectronic manufacturing.

Abstract We report an innovative and facile approach to fabricating an ultrasensitive plasmonic paper substrate for surface-enhanced Raman spectroscopy (SERS). The approach exploits the self-assembling capability of poly(styrene-b-2-vinyl pyridine) block copolymers to form a thin film at the air-liquid interface within the single microdroplet scale for the first time and the subsequent in situ growth of silver nanoparticles (AgNPs). The concentration of the block copolymer was found to play an essential role in stabilizing the droplets during the mass transfer phase and formation of silver nanoparticles, thus influencing the SERS signals. SEM analysis of the morphology of the plasmonic paper substrates revealed the formation of spherical AgNPs evenly distributed across the surface of the formed copolymer film with a size distribution of 47.5 nm. The resultant enhancement factor was calculated to be 1.2 × 107, and the detection limit of rhodamine 6G was as low as 48.9 pM. The nanohybridized plasmonic paper was successfully applied to detect two emerging pollutants—sildenafil and flibanserin—with LODs as low as 1.48 nM and 3.45 nM, respectively. Thus, this study offers new prospects for designing an affordable and readily available, yet highly sensitive, paper-based SERS substrate with the potential for development as a lab-on-a-chip device.

Is it possible to tell how interdisciplinary and out-of-the-box scientific papers are, or which papers are mainstream? Here we use the bibliographic coupling network, derived from all physics papers that were published in the Physical Review journals in the past century, to try to identify them as mainstream, out-of-the-box, or interdisciplinary. We show that the network clusters into scientific fields. The position of individual papers with respect to these clusters allows us to estimate their degree of mainstreamness or interdisciplinarity. We show that over the past decades the fraction of mainstream papers increases, the fraction of out-of-the-box decreases, and the fraction of interdisciplinary papers remains constant. Studying the rewards of papers, we find that in terms of absolute citations, both, mainstream and interdisciplinary papers are rewarded. In the long run, mainstream papers perform less than interdisciplinary ones in terms of citation rates. We conclude that to avoid a unilateral trend towards mainstreamness a new incentive scheme is necessary., Competing Interests: The authors have declared that no competing interests exist.

A popular physics legend holds that scissors can cut paper with a speed faster than light. Here this counter-intuitive myth is investigated theoretically using four simple examples of scissors. For simplicity, all cases will involve a static lower scissors blade that remains horizontal just under the paper. In the first case, the upper blade will be considered perfectly rigid as it rotates around and through the paper, while in the second case, a rigid upper blade will drop down to cut the paper like a guillotine. In the third case, the paper is cut with a laser rotating with a constant angular speed that is pointed initially perpendicular to the paper at the closest point, while in the fourth case, the uniformly rotating laser is pointed initially parallel to the paper. Although details can be surprising and occasionally complex, all cases allow sections of the paper to be cut faster than light without violating special relativity. Therefore, the popular legend is confirmed, in theory, to be true.

In this paper, the thermo-electric, phonon, electronic, and optical properties of the C3N monolayer have been investigated using the Wien2K computational code based on first principles calculations in the framework of the density functional theory. The study of electronic properties shows the behavior of non-magnetic semiconductors with an indirect gap with a value of 0.5 electron volts for this two-dimensional structure. Also, optical properties such as dielectric function, reflection, energy loss function, absorption coefficient, and optical conductivity are calculated. C3N monolayer is optically anisotropic in z and x direction, which according to the refractive index diagram leads to birefringence, which is a key parameter for this compound's linear optical performance. The results provide a fundamental understanding of the design of composite structures used in nanodevices based on two-dimensional advanced materials. The linear response approach along the symmetric points calculates the phonon dispersion diagram. The results indicate the absence of negative modes in the phonon spectrum, indicating that the structure is dynamically stable. Investigating the thermoelectric properties of the C3N monolayer using the semi-classical Boltzmann theory shows that this monolayer has a value coefficient (ZT) close to one at room temperature and temperatures lower than room temperature. As a result, it can be proposed as a candidate for thermoelectric applications.

Many non-classicality indicators are used to measure the quantum effects of different systems. Kenfack's and Sadeghi's non-classicality indicators are introduced regarding the amount of Wigner distribution function's negativities and interferences in phase space quantum mechanics, respectively. Kenfack’s non-classicality indicator is used for cases just in the Wigner representation, whereas Sadeghi’s non-classicality indicator is effectively, applied for some real distribution functions. In this paper, we investigate these non-classicality indicators for the entangled photon number states in the Wigner, Husimi, and Rivier representations. It is shown that for a two-level entangled state, Sadeghi's indicator has more benefits to measure entanglement with respect to Kenfack's indicator. For the two-level entangled state, we also show a correspondence between Sadeghi's non-classicality indicator and the Von Neumann entropy. It is also shown that for the superposition of the squeezed number state and ground number state, the squeezing parameter affects the entanglement feature and Sadeghi's non-classicality indicator increases with the increase of the squeezing parameter.

It is essential to establish a multi-dimensional postgraduate quality evaluation system for student assessment and training. This study aimed to explore the construction of the multiindex and hierarchical comprehensive evaluation system for postgraduate training in science and engineering based on the Context, Input, Process, Product (CIPP) model using Analytic Hierarchy Process. It involved 756 postgraduates in physics and engineering who were randomly selected via the Internet. Data were collected from the questionnaire about postgraduates' basic information. After collection, Factor Analysis was used to verify the rationality of the design of second-level and third-level indicators, and adjust the corresponding weights. On this basis, Cluster Analysis was used to classify the training quality of the postgraduates based on their scores on academic ability, basic quality, and social ability indicators. The results revealed that the index system includes 4 first-level indicators,12 second-level indicators and 36 third-level indicators, and different weights being assigned to the indicators according to their influence on the training quality of postgraduates in science and engineering. This study also provides some reference for the quality of science and engineering postgraduate training in Chinese universities by proposing relevant measures, which could be interesting also for international audience.