Properties Of Core Research Articles

Investigation of influence factors on CO2 flowback characteristics and optimization of flowback parameters during CO2 dry fracturing in tight gas reservoirs

CO2 dry fracturing is a promising alternative method to water fracturing in tight gas reservoirs, especially in water-scarce areas such as the Loess Plateau. The CO2 flowback efficiency is a critical factor that affects the final gas production effect. However, there have been few studies focusing on the flowback characteristics after CO2 dry fracturing. In this study, an extensive core-to-field scale study was conducted to investigate CO2 flowback characteristics and CH4 production behavior. Firstly, to investigate the impact of core properties and production conditions on CO2 flowback, a series of laboratory experiments at the core scale were conducted. Then, the key factors affecting the flowback were analyzed using the grey correlation method based on field data. Finally, taking the construction parameters of Well S60 as an example, a dual-permeability model was used to characterize the different seepage fields in the matrix and fracture for tight gas reservoirs. The production parameters after CO2 dry fracturing were then optimized. Experimental results demonstrate that CO2 dry fracturing is more effective than slickwater fracturing, with a 9.2% increase in CH4 recovery. The increase in core permeability plays a positive role in improving CH4 production and CO2 flowback. The soaking process is mainly affected by CO2 diffusion, and the soaking time should be controlled within 12 h. Increasing the flowback pressure gradient results in a significant increase in both CH4 recovery and CO2 flowback efficiency. While, an increase in CO2 injection is not conducive to CH4 production and CO2 flowback. Based on the experimental and field data, the important factors affecting flowback and production were comprehensively and effectively discussed. The results show that permeability is the most important factor, followed by porosity and effective thickness. Considering flowback efficiency and the influence of proppant reflux, the injection volume should be the minimum volume that meets the requirements for generating fractures. The soaking time should be short which is 1 day in this study, and the optimal bottom hole flowback pressure should be set at 10 MPa. This study aims to improve the understanding of CO2 dry fracturing in tight gas reservoirs and provide valuable insights for optimizing the process parameters.

Developing Bioactive Dental Resins for Restorative Dentistry.

Despite its reputation as the most widely used restorative dental material currently, resin-based materials have acknowledged shortcomings. As most systematic survival studies of resin composites and dental adhesives indicate, secondary caries is the foremost reason for resin-based restoration failure and life span reduction. In subjects with high caries risk, the microbial community dominated by acidogenic and acid-tolerant bacteria triggers acid-induced deterioration of the bonding interface and/or bulk material and mineral loss around the restorations. In addition, resin-based materials undergo biodegradation in the oral cavity. As a result, the past decades have seen exponential growth in developing restorative dental materials for antimicrobial applications addressing secondary caries prevention and progression. Currently, the main challenge of bioactive resin development is the identification of efficient and safe anticaries agents that are detrimental free to final material properties and show satisfactory long-term performance and favorable clinical translation. This review centers on the continuous efforts to formulate novel bioactive resins employing 1 or multiple agents to enhance the antibiofilm efficacy or achieve multiple functionalities, such as remineralization and antimicrobial activity antidegradation. We present a comprehensive synthesis of the constraints and challenges encountered in the formulation process, the clinical performance-related prerequisites, the materials' intended applicability, and the current advancements in clinical implementation. Moreover, we identify crucial vulnerabilities that arise during the development of dental materials, including particle aggregation, alterations in color, susceptibility to hydrolysis, and loss of physicomechanical core properties of the targeted materials.

Exploring the 3D Conformation of Hard-Core Soft-Shell Particles Adsorbed at a Fluid Interface.

The encapsulation of a rigid core within a soft polymeric shell allows obtaining composite colloidal particles that retain functional properties, e.g., optical or mechanical. At the same time, it favors their adsorption at fluid interfaces with a tunable interaction potential to realize tailored two-dimensional (2D) materials. Although they have already been employed for 2D assembly, the conformation of single particles, which is essential to define the monolayer properties, has been largely inferred via indirect or ex situ techniques. Here, by means of in situ atomic force microscopy experiments, the authors uncover the interfacial morphology of hard-core soft-shell microgels, integrating the data with numerical simulations to elucidate the role of the core properties, of the shell thicknesses, and that of the grafting density. They identify that the hard core can influence the conformation of the polymer shells. In particular, for the case of small shell thickness, low grafting density, or poor core affinity for water, the core protrudes more into the organic phase, and the authors observe a decrease in-plane stretching of the network at the interface. By rationalizing their general wetting behavior, such composite particles can be designed to exhibit specific inter-particle interactions of importance both for the stabilization of interfaces and for the fabrication of 2D materials with tailored functional properties.

Selective Synthesis using ETFBO: A New Strategy for the Preparation of Hexahydro‐1H‐pyrrolo[1,2‐c]imidazol‐1‐one.

AbstractIn this work, we report the regiospecific and stereoselective synthesis of novel pyrrolo thioxoimidazolidinones with promising biological activities due to the inherent pharmaceutical properties of thioxoimidazolidinone core. The reaction of different thioxoimidazolidinones with trans‐4‐ethoxy‐1,1,1‐trifluorobut‐3‐en‐2‐one (ETFBO) yields bicyclic 1,3‐diaza heterocycles bearing the trifluoromethyl (CF3) moiety. Our investigation involved both depth experimental analysis and theoretical calculations to fathom out the mode of reaction of this building block and elucidate the underlying mechanism operating for the observed reactions. Remarkably, this unusual mechanism retained the ethanol moiety from the building block in the final products, deviating from conventional nucleophilic reactions reported in the literature.

Free vibration analysis of a skew sandwich plate with bamboo biocomposite and polylactic acid core under temperature and moisture conditions

This article investigates the impact of moisture and temperature on vibration characteristics of bio-composite skew-laminated composite sandwich (SLCS) plates. The bio-composite SLCS plates with bamboo face sheets and polylactic acid (PLA) cores are biodegradable, radiolucent, lightweight, high strength, and withstand vibrations. The coupled thermo-elastic and hygro-elastic finite element (FE) model of the SLCS plate is derived using the higher-order shear deformation theory (HSDT). An initial stress stiffness matrix is developed using the nonlinear strain-displacement relations to incorporate the effect of temperature and moisture in FE modeling. Temperature and moisture-dependent material properties of bamboo fiber-reinforced biocomposite (BFB) and PLA core are employed for the analysis. A comprehensive investigation has been carried out to study the impact of moisture and temperature situations with different geometrical parameters and various skew angles on the frequency of the SLCS plate. The results indicate that the biocomposite sandwich material has excellent potential for structural applications under different environmental conditions in various applications like food processing, and biomedical applications, including MRI and CT scan beds.

An estimate of absolute shear-wave speed in the Earth’s inner core

Observations of seismic body waves that traverse the Earth’s inner core (IC) as shear (J) waves are critical for understanding the IC shear properties, advancing our knowledge of the Earth’s internal structure and evolution. Here, we present several seismological observations of J phases detected in the earthquake late-coda correlation wavefield at periods of 15–50 s, notably via the correlation feature I-J, found to be independent of the Earth reference velocity model. Because I-J is unaffected by compressional wave speeds of the Earth’s inner core, outer core, and mantle, it represents an autonomous class of seismological measurements to benchmark the inner core properties. We estimate the absolute shear-wave speed in the IC to be 3.39 ± 0.02 km/s near the top and 3.54 ± 0.02 km/s in the center, lower than recently reported values. This is a 3.4 ± 0.5% reduction from the Preliminary Reference Earth Model (PREM), suggesting a less rigid IC than previously estimated from the normal mode data. Such a low shear-wave speed requires re-evaluating IC composition, including the abundance of light elements, the atomic properties and stable crystallographic phase of iron, and the IC solidification process.

Effect of austempering time on multiphase microstructure evolution and properties of carburized Cr-Mn-Si alloyed steel subjected to bainitization quenching & partitioning heat treatment

An innovative multistage heat treatment, that combines Bainitization and Quenching & Partitioning processes (BQ&P) can be applied to obtain multiphase microstructure in the carburized surface layer comprising nanobainite, ultra-fine martensite and retained austenite. In this study, a carburized medium-carbon Cr-Si-Mn alloyed steel was treated by BQ&P treatments with 20%, 40% and 100% of advancement of bainitic transformation in the top surface to investigate the effect of isothermal holding time on microstructure evolution and properties.Extending the bainitization time leads to an increase in the bainitic ferrite content in the microstructure and more significant fragmentation of the residual austenite blocks. It was shown that multiphase microstructure consisting of nanobainite, ultra-fine martensite and retained austenite results in the higher hardness and wear resistance of the case as compared to the fully bainitic microstructure. The enhanced properties results from the strengthening effect of additional martensite fraction and higher amount of stabilized austenite prone to transformation under friction (transformation induced plasticity, TRIP effect). Furthermore, adjusted parameters of the process lead to favorable mechanical properties in a medium-carbon core (YS ∼ 1430 MPa, UTS ∼ 1820 MPa, KV ∼ 20 Jcm−2). The ability to tailor mechanical and service properties of steel by controlling the fraction of particular phases along with a significant reduction of heat treatment time might designate the BQ&P process to industrial application, e.g. carburized gear wheels.

Re-examination of nonlinear vibration, nonlinear bending and thermal postbuckling of porous sandwich beams reinforced by graphene platelets

This paper re-examines the nonlinear free vibration, nonlinear bending and thermal postbuckling behaviors of porous sandwich beams with graphene platelets (GPL) reinforcements rested on elastic foundations. We remove the equivalent isotropic model (EIM) and introduce an inhomogeneous model. The shear modulus together with the Young’s moduli for porous GPLRC core is determined by a generic Halpin–Tsai model with porosity. Mechanical properties of both porous GPLRC core and metal face sheets are temperature dependent. Based on the framework of higher order shear deformation beam theory, the motion equations of porous sandwich beams with GPL reinforcements are established. In the modeling, the von Kármán kinematic nonlinearity, beam-foundation interaction and thermal effect are considered. By employing the two-step perturbation method, the analytical solutions are obtained for the nonlinear vibration and nonlinear bending as well as thermal postbuckling problems. Numerical investigations are performed for comparing the results obtained from the EIM and the present model. The outcomes reveal that the EIM is invalid for linear free vibration, thermal buckling and postbuckling analyses of porous sandwich beams with GPL reinforcements, but the EIM is valid in some cases for nonlinear bending and nonlinear vibration analyses of the same beam.

Burnup-control drum coupling characteristics investigation of lead–bismuth eutectic-cooled solid reactor

As an advanced research tool, neutronics and thermal-hydraulics coupling have a wide range of promising applications in the field of nuclear energy. This paper develops a burnup-control drum coupling code based on the Monte Carlo code RMC and the computational fluid dynamics (CFD) program STAR-CCM +. The dynamic adjustment of the control drums' position and more realistic prediction of reactor neutronics and thermal-hydraulics is achieved by updating the nuclide density, solving the control drum value function and updating the neutronics model in the process of burnup calculation. The core of a lead–bismuth-cooled solid reactor was also studied to investigate the neutronics and thermal-hydraulics properties of the solid core when the effective multiplication factor was kept at about 1.0, and the core's power and temperature variation patterns during the lifetime were obtained. The results of the study show that the simulation of the coupling code achieves the design purpose. In addition, the solid core's maximum fuel and cladding temperatures decrease with the deepening of the burnup.

Effect of low magnetic field heat treatment process on grain sizes and soft magnetic properties of Finemet cores

In this study, we investigate the effect of low transverse magnetic field annealing on the soft magnetic properties of cores made of industrial Finemet ribbons. The variation of static/dynamic magnetic properties and average grain size of the cores obtained by zero-field annealing (ZFA), secondary-field annealing (SMA) and direct-field annealing (DMA) are studied in detail. It is found that the average grain size obtained by DMA decreased compared to that of the ZFA sample, while the average grain size increased slightly after SMA. The effective permeability (μe) of the ZFA sample after SMA decrease less than that of the ZFA sample with increasing frequency. The μe of the DMA sample decreases significantly at the low-frequency stage but tends to decrease smoothly overall, maintaining high effectiveness at high frequencies magnetic permeability. For example, at 100 kHz, the μe of ZFA at 550 °C temperature is only 0.6 × 104, while the μe of SMA and DMA are 2.0 × 104 and 2.2 × 104, respectively. Meanwhile, the Hc = 1.85 A/m, Br = 0.59 T after ZFA and Hc = 1.67 A/m after DMA show no significant decrease compared to ZFA. While Hc = 0.55 A/m, Br = 0.08 T after SMA. Due to the field anisotropy constant Ku generated after SMA and DMA, the average anisotropy constant is dominated by Ku, the domain structure becomes simple and uniform, and the domain width becomes larger. This leads to a decrease in core losses with increasing frequency and improves the high-frequency characteristics of the core. These results can provide good guidance for performance optimization for Finemet alloys in a wide frequency range.

Amplifying the photovoltaic properties of phenylene dithiophene core based non-fused ring by engineering the terminal acceptors modification to enhance the efficiency of organic solar cells

In this study, a series of eight non-fused rings-based semiconducting acceptors (AR1-AR8) were computationally developed by making modifications to the parent molecule (PTICO). In this study, a DFT analysis was conducted at an accurately chosen level of theory to gather a comprehensive inventory of the optoelectronic characteristics of AR1-AR8 and PTICO. The findings indicate that all recently developed molecules exhibit a bathochromic shift in their maximum UV–visible absorbance (λmax) with a smaller band gap (Eg). AR1 has demonstrated the most significant red shift in UV–visible absorbance and possesses the smallest Eg when compared to other recently developed acceptors. AR2 acceptor has shown the best results both as electron and hole-transporting materials owing to its smallest value of reorganization energy for electrons and holes. J61 donor was engaged to calculate the open-circuit voltage (VOC) and the highest VOC with maximum FF % value was observed in AR4. The investigation of charge transfer was also conducted utilizing J61 in conjunction with the AR4 acceptor. Natural transition orbitals (NTO) have also been inspected to recognize the percentage electron transport contribution (% ETC) from the ground state to the first excites state (S0 to S1). The findings of this research suggest that the modified acceptors exhibit potential for practical implementation in the development of organic solar cells that possess improved photovoltaic performance.

In-situ Y3Al5O12 enhances comprehensive properties of alumina-based ceramic cores by vat photopolymerization 3D printing

In-situ Y3Al5O12 enhances comprehensive properties of alumina-based ceramic cores by vat photopolymerization 3D printing

Free vibration analysis of the sandwich structured composite annular plates: Numerical and experimental investigation

Sandwich structures are interesting structural elements due to their high stiffness-to-weight ratio, high fatigue resistance, and excellent vibration characteristics. The aerospace industry relies heavily on these types of structures considering the different optimized materials and shapes available for sandwich construction. In the present study, vibration aspects of annular sandwich structures with composite laminates and a 3D printed honeycomb core are investigated in both the numerical and experimental methods. Amongst the various shapes of sandwich structures, annular sector plates are predominantly used in the construction of modern bridges, aircrafts, and automobile parts. Furthermore, the investigation of annular sandwich plates featuring GFRP facesheet and 3D printed PLA cores are studied in a very limited extent. In order to obtain the sector plates experimentally, Glass Fiber Reinforced Polymer (GFRP) laminates are fabricated by hand layup techniques, and the 3D printing Poly-lactic Acid (PLA) honeycomb core is manufactured using Fused Deposition Modelling (FDM). The material properties of honeycomb core and composite skins are estimated with the help of Gibson formulation and rule of mixture, respectively. Based on available literature, the analysis approach is validated through numerical analysis using ANSYS Finite Element (FE) software. Also, the frequency responses of annular sandwich plate were measured in both experimental and numerical analysis and the results showed good agreement. However, in order to describe the effectiveness of annular composite sandwich plates, parametric studies are carried out in terms of natural frequencies and mode shapes with different configurations of core geometry, ply orientation, boundary constraints, and inner to outer radius ratio. The research outcome highlights that the optimum angle ply orientation, core height of 12.5 mm with clamped–clamped condition and inner to outer radius of 0.75 mm yields better structural stiffness.

Fe3O4 Core–Shell Nanostructures with Anticancer and Antibacterial Properties: A Mini-Review

Core–shell nanoparticles are functional materials with tailored properties, able to improve the requirements of various applications. Both core and shell components can be inorganic or organic, and there are numerous studies in this field regarding their synthesis methods, properties, and applications. This review aims to study core–shell nanostructures with Fe3O4 cores and different shell types, observing their antibacterial and anticancer properties. By the type of coating, Fe3O4 core–shell nanoparticles (NPs) are classified into four categories: metal-coated NPs, metal-organic framework (MOF) coated NPs, metal oxide coated NPs, and polymer-coated NPs. Each category is briefly presented, emphasizing anticancer or antibacterial properties and specific applications (cancer diagnosis or therapy, drug carrier). Moreover, synthesis methods and particle size for both core and shell nanostructures, as well as the magnetic properties of the final core–shell material, are summarized in this review. Most of the consulted papers discussed sphere-like core–shell nanoparticles obtained by chemical methods such as coprecipitation, hydrothermal, and green synthesis methods using plant extract. These types of core–shell nanoparticles could be used as drug nanocarriers for tumor-targeted drug delivery, hyperthermia treatment, or contrast agents. Further work needs to be conducted to understand nanoparticles’ interaction with living cells and their traceability in the human body.

Deictic Framing Performance Fails to Generalize to Other Perspective-Taking Tasks

The behavioral processes underlying perspective taking have not been studied extensively. One approach to understanding and enhancing perspective taking, deictic framing, has been proposed. Proponents of this approach have suggested that deictic framing is a core property of perspective taking. A training protocol based on deictic framing has been developed and tested, but researchers generally evaluate the effectiveness of the protocol using tasks that have a similar format to the training protocol. Little research has examined the protocol’s effectiveness for improving performance in different perspective-taking tasks. We investigated generalization of the performance of three groups of university students trained with a deictic-framing protocol (or not) and tested with two other perspective-taking tasks: a visuospatial perspective taking using a cupboard containing a range of objects and a version of the implicit relational assessment procedure specifically designed to measure perspective taking. The first group was trained with the original verbal protocol with deictic expressions; the second group with the same protocol involving nondeictic words; and the third group was merely exposed to deictic expressions as a control condition. The results suggested that deictic framing is not fundamental to perspective taking, as the performance of the two experimental groups was not significantly different from the control group’s performance. Identification of specific stimulus functions involved in successful perspective taking and how those functions can be established should be addressed in future research.

A Nonlinear Repeated Impact Model of Auxetic Honeycomb Structures Considering Geometric Nonlinearity and Tensile/Compressive Deformation

Abstract This study aims to improve the impact protection performance of composite structures by combining a honeycomb core with negative Poisson’s ratio and graphene platelets reinforced (GPR) face sheets. The paper investigates the nonlinear repeated low-velocity impact responses of auxetic honeycomb composite plates, taking into account loading-unloading-reloading processes. Effective material properties of the auxetic honeycomb core and GPR face sheets are obtained by using the proposed modified Gibson function and Halpin–Tsai model. Then, taking into account geometric nonlinearity, the nonlinear equations of motion for the system were derived by Hamilton's principle. Afterward, the time-varying contact force between the composite plate and a spherical impactor is defined by the modified nonlinear Hertz contact theory. The Galerkin method and variable-step Runge–Kutta algorithm are selected to obtain nonlinear impact responses. The proposed methods are verified by finite element simulation and experiment. Finally, the study evaluates the effects of key parameters on the nonlinear repeated low-velocity impact responses.

High-resolution core data and machine learning schemes applied to rock facies classification

Abstract This paper presents core analysis practices developed to increase the value of cores in reservoir characterization workflows. Core analysis traditionally implies extensive rock testing programmes that require large numbers of plug samples. Numerous stakeholders compete for intact core material and often do not base sample selection criteria on objective and reliable information. As a consequence, samples dedicated to core analysis programmes consume a significant fraction of the material available, yet they are selected on the basis of very little a priori information and therefore do not necessarily capture the complexity of the targeted formations. In an attempt to change this paradigm, we promote a more integrated core analysis solution combining transdisciplinary, high-resolution, non-destructive measurements on whole cores, for an early yet objective description of cores and the rapid estimation of formation properties. The first section describes multidisciplinary and non-destructive tests designed to increase the value of information from cores while keeping a minimal footprint. Core samples are scanned along a fit-for-purpose surface, with a collection of sensors interfaced to the same table-top equipment. Technologies including ultra-high-resolution pictures, elemental composition and the direct measurements of geomechanical properties provide continuous and high-resolution profiles with a unique depth reference. Panoramic pictures are processed to extract textural and colour features and grain size distributions. Grain size distributions are backed up by analysis of topographical maps created with a laser scan. The results are combined under one unique format, thereby easing interdisciplinary work from the verification of standard tests (routine core analysis, rock mechanical test) to the construction of robust predictive rock models. The paper describes machine learning schemes applied to core datasets. Unsupervised schemes are designed to identify rock facies, while supervised schemes are used to classify tested rocks into predefined rock facies with known petrophysical properties. Case studies highlight the benefits of this approach of core analysis in conjunction with artificial intelligence for the automated identification and classification of rock facies. This novel approach to core analysis leverages a detailed and comprehensive knowledge of the distributions of core properties, available under one unique format for all disciplines, which eases interdisciplinary work and significantly improves existing core analysis standards. It also provides a sound basis to train artificial intelligence rock reservoir property predictors linking well-log data to core-based lithofacies signatures.

Properties of the dense cores and filamentary structures in the Vela C molecular cloud

The initial and boundary conditions of the Galactic star formation in molecular clouds are not well understood. In an effort to shed new light on this long-standing problem, we measured the properties of dense cores and filamentary structures in the Vela C molecular cloud, observed with Herschel. We used the hires algorithm to create high-resolution surface densities (11.7″) from the Herschel multiwavelength dust continuum. We applied the getsf extraction method to separate the components of sources and filaments from each other and their backgrounds before detecting, measuring, and cataloging the structures. The cores and filamentary structures constitute 40% of the total mass of Vela C; most of the material is in the low-density molecular background cloud. We selected 570 reliable cores, of which 149 are the protostellar cores and 421 are the starless cores. Almost 78% (329 of 421) of the starless cores were identified with the gravitationally bound prestellar cores. The exponent of the CMF (α = 1.35) is identical to that of the Salpeter IMF. The high-resolution surface density image helped us determine and subtract backgrounds and measure the sizes of the structures. We selected 68 filaments with at least one side that appeared not blended with adjacent structures. The filament widths are in the range from 0.15 pc to 0.63 pc, and have a median value of W = 0.3 ± 0.11 pc. The surface densities of filaments are well correlated with their contrasts and linear densities. Within uncertainties of the filament instability criterion, many filaments (39) may be both supercritical and subcritical. A large fraction of filaments (29), in which are found 94 prestellar cores, 83 protostellar cores, and only 1 unbound starless core, can definitely be considered supercritical. Taking into account the uncertainties, the supercritical filaments contain only prestellar and protostellar cores. Our findings support the idea that there is a direct relationship between the CMF and IMF and that filaments play a key role in the formation of prestellar cores, which is consistent with the previous Herschel results.

ALMA-IMF

Context.Among the most central open questions regarding the initial mass function (IMF) of stars is the impact of environment on the shape of the core mass function (CMF) and thus potentially on the IMF.Aims.The ALMA-IMF Large Program aims to investigate the variations in the core distributions (CMF and mass segregation) with cloud characteristics, such as the density and kinematic of the gas, as diagnostic observables of the formation process and evolution of clouds. The present study focuses on the W43-MM2&MM3 mini-starburst, whose CMF has recently been found to be top-heavy with respect to the Salpeter slope of the canonical IMF.Methods.W43-MM2&MM3 is a useful test case for environmental studies because it harbors a rich cluster that contains a statistically significant number of cores (specifically, 205 cores), which was previously characterized in Paper III. We applied a multi-scale decomposition technique to the ALMA 1.3 mm and 3 mm continuum images of W43-MM2&MM3 to define six subregions, each 0.5–1 pc in size. For each subregion we characterized the probability distribution function of the high column density gas,η-PDF, using the 1.3 mm images. Using the core catalog, we investigate correlations between the CMF and cloud and core properties, such as theη-PDF and the core mass segregation.Results.We classify the W43-MM2&MM3 subregions into different stages of evolution, from quiescent to burst to post-burst, based on the surface number density of cores, number of outflows, and ultra-compact HII presence. The high-mass end (>1M⊙) of the subregion CMFs varies from close to the Salpeter slope (quiescent) to top-heavy (burst and post-burst). Moreover, the second tail of theη-PDF varies from steep (quiescent) to flat (burst and post-burst), as observed for high-mass star-forming clouds. We find that subregions with flat secondη-PDF tails display top-heavy CMFs.Conclusions.In dynamical environments such as W43-MM2&MM3, the high-mass end of the CMF appears to be rooted in the cloud structure, which is at high column density and surrounds cores. This connection stems from the fact that cores and their immediate surroundings are both determined and shaped by the cloud formation process, the current evolutionary state of the cloud, and, more broadly, the star formation history. The CMF may evolve from Salpeter to top-heavy throughout the star formation process from the quiescent to the burst phase. This scenario raises the question of if the CMF might revert again to Salpeter as the cloud approaches the end of its star formation stage, a hypothesis that remains to be tested.

Effect of annealing process on magnetic properties of Fe80Co3Si3B10P1C3 amorphous alloy magnetic cores

Effect of annealing process on magnetic properties of Fe80Co3Si3B10P1C3 amorphous alloy magnetic cores