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The dielectric constant is a critical parameter in many energy-related applications. Typically, increasing the dielectric constant of soft materials involves adding high dielectric constant polar liquids or inorganic fillers, but there are limitations to this approach due to safety concerns with volatile and flammable solvents and the agglomeration of inorganic fillers. An alternative approach is to add zwitterionic liquids that exhibit exceptionally high dielectric constants with negligible volatility. Here, we report the synthesis of a series of zwitterionic liquids containing an imidazolium cation, exhibiting the highest dielectric constant among all organic molecules (∼350 at 293 K). The cation–anion linkage was tailored in a wide range between three and nine carbons, rendering the zwitterion dipole from 25 to 52 D. Comparing the dielectric constant for zwitterions with different anions (i.e., sulfonylimide, sulfonate, and carboxylate) reveals the beneficial impacts of the delocalized sulfonylimide anion vs the carboxylate anion due to the enlarged molecular dipole and more homogenous liquid morphology. Molecular dipole and liquid morphology are identified as the keys to developing high dielectric constant zwitterionic liquids. The extremely high dielectric constant accessible with the proposed molecular design paves new avenues for developing high dielectric constant zwitterions that act as dielectricizers. [ABSTRACT FROM AUTHOR]

A milled recycled asphalt pavement (RAP) particle can be a cluster of one or more aggregates coated with an aged RAP binder. While RAP material is added to virgin aggregates and binder in a pugmill, the RAP cluster undergoes dissociation or agglomeration, depending on the cluster size and thermo-physical conditions inside the pugmill. The degree of dissociation or agglomeration of RAP material has an important relation with the degree of RAP binder availability. The RAP binder availability in mix design depends on the exposed surface area of dissociated coarse RAP particles and also on the agglomeration tendency of fine RAP particles. In the present study, the degree of RAP binder availability (DoAv), cluster dissociation of course RAP, and agglomeration tendency of fine RAP particles were examined at different mixing durations inside an asphalt pugmill—60 s, 120 s, and 180 s. The study examined whether the RAP cluster dissociation and postmixing agglomeration has any effect on the RAP binder availability. The degree of RAP binder availability of RAP mix was found by determining the virgin binder requirement of RAP mixes in excess of optimum binder content determined for the control mix prepared using virgin aggregates. Cluster dissociation and agglomeration was studied by hot mixing of RAP fractions in a pugmill with abrasive charges, followed by sieving. The statistical analysis of data found that RAP mixes incorporating fractionated fine RAP material exhibited higher DoAv at every mixing duration. For mixes incorporating fractionated coarse RAP, cluster dissociation index was positively correlated with DoAv, which implied that RAP cluster dissociation is a possible reason for RAP binder availability. In mixes incorporating fractionated fine RAP fractions, the RAP particles got agglomerated. The agglomeration index was found to correlate well with RAP binder availability, thereby establishing that agglomeration tendency in fine RAP fractions can be considered as an indicator of RAP binder availability. [ABSTRACT FROM AUTHOR]

Borophosphosilicate glasses with varying sodium ion concentrations were investigated for their, structural, thermal, and electrical properties. All the obtained glasses were transparent except the glass with the highest sodium content, which exhibited translucency due to inhomogeneities. Increasing sodium content led to reduced boron and silicon content while maintaining a constant B/Si ratio, indicating progressive depolymerization of the glass network. Confocal microscopy, scanning electron microscopy, and atomic force microscopy showed homogeneous and granular structure for samples with lower sodium content, but higher sodium content resulted in visible agglomeration/nanocrystallization. X-ray diffractograms showed amorphous nature for most samples, with samples doped with the highest concentrations of Na 2 O showing several broad reflections suggesting nanoscale crystallinity. Fourier-transform infrared spectroscopy revealed shifts in dominant bands with increasing sodium content, indicating depolymerization of the borate network. An observed decrease in glass transition temperature and thermal stability with increasing sodium content was attributed to depolymerization and formation of non-bridging oxygens. Impedance spectroscopy revealed two relaxation processes associated with the transport of Na+ ions through two different regions. DC conductivity and activation energy predominantly increased with the sodium ion content at high temperatures. [ABSTRACT FROM AUTHOR]

Ionomeric polymer‐metal composites (IPMC) are advanced materials designed to mimic biological systems. Their performance depends on various factors, including electrical stimulus intensity, membrane hydration, ionic migration, and Young's modulus. However, there is a lack of studies in the literature investigating how the water absorption capacity and elastic modulus change over time in IPMCs. Understanding the hydration level variation as a function of time is essential because as this parameter deviates, the ionic migration capacity and Young's modulus also change, altering the device's electromechanical efficiency over time. To address this research gap, Nafion/Pt‐based IPMC devices exchanged with four monovalent cations (H+, Li+, Na+, and K+) and one ionic liquid (1‐butyl‐3‐methylimidazolium—BMIM+) were prepared, and a comprehensive investigation on how the water absorption capacity and Young's modulus vary as a function of time, relative humidity (RH), and counterion size was performed. The results revealed that the water uptake capacity is significantly higher and occurs more rapidly at higher RH levels and when the counterion's ionic radius decreases. Consequently, the time required for the device to reach osmotic equilibrium can range from 40 to 270 min, depending on the RH and counterion used. Furthermore, it was observed that the first natural frequency and Young's modulus also exhibit time‐dependent behavior. Under constant RH conditions, the mechanical properties of the IPMC can vary by up to 50% in less than 60 min. Notably, the combined results from water uptake capacity, Young's modulus, electrochemical impedance spectroscopy, and electromechanical response analyses (including blocking force, displacement, displacement rate, current, coulombic efficiency, and voltage) suggest that a morphological transformation within the polymer is likely to occur once RH exceeds 60%. This finding strengthens the hypothesis that ion migration is mainly influenced by their movement through Nafion's ionomeric channels rather than the filling of ionic agglomerates. [ABSTRACT FROM AUTHOR]

The high-temperature roasting/smelting process of copper and zinc concentrates will cause the mercury in the concentrate to evaporate into the flue gas, and most of the mercury in the flue gas will eventually enter the waste acid in its ionic form. A highly efficient mercury removal agent M201 with long carbon chains and loaded active functional groups can adsorb and disperse fine particles for mercury removal in the system. Through bridging, the linear structure is woven into a network to achieve large-scale capture and dispersion of fine particles and colloidal substances. The recommended operating conditions for developing mercury deep purification technology are as follows: M201 reagent concentration of 50 g/L, 6 mL/L added acid solution, room temperature, mixing time of 5 min, air flotation time of 10 min, ventilation rate of 0.1 L/min, H2SO4 concentration of 33.67 g/L, and the residual mercury content of 2 mg/L (the mercury content reaches 0.01 mg/L after two-stage mercury removal treatment). Meanwhile, the residual arsenic content is 21.9 mg/L. This study shows a better separation of arsenic and mercury and achieves one-step mercury removal. [ABSTRACT FROM AUTHOR]

[Display omitted] • The PPC contains a bunch of heteroatoms to narrow the polarization of material under high current density conditions. • The presence of PPC leads to the formation of NFVP nanoparticles and restrains the agglomeration of NFVP. • The NFVP/PPC composite displays an outstanding rate performance and cycle stability. Na super-ion conductor type material Na 3 V 2 (PO 4) 3 has been widely researched as the cathode of sodium-ion batteries (SIBs) in recent years, but the unsatisfying cost of Na 3 V 2 (PO 4) 3 impedes its wide application in SIBs. In this study, iron element is used to replace part of vanadium in Na 3 V 2 (PO 4) 3 to reduce its expense, and pine pollen is applied for the first time as a very effective carbon source to improve the performance of Na 4 FeV(PO 4) 3. The fabricated composite material achieves a capacity of 105 mA h g−1 under 0.2 C and fascinating cycling stability over 94 % under 2 C for 500 cycles and 98 % under 10 C for 1000 cycles. The excellent cycle performance is caused by the involvement of pine pollen that acts as a carbon matrix to enhance the electron conductivity and block the agglomeration of active material effectively, thus the well-dispersed nano sized Na 4 FeV(PO 4) 3 shortens the diffusion path of sodium ion and gains a remarkable rate capability. Moreover, the distinguished reversibility during the charge and discharge procedures is ascribed also to the robust structure of Na 4 FeV(PO 4) 3. This work provides an efficient route to realize the economic cathode material of SIBs with good performance. [ABSTRACT FROM AUTHOR]

Developing efficient methods for cocrystal production is crucial to improving drug solubility and bioavailability. This study utilized the spherical agglomeration-co-crystallization (SA-CC) method to produce spherical ibuprofen-nicotinamide (IBU-NICO) cocrystals. This method used ethanol (ETA) as a solvent and a mixture of deionized water and PEG-4000 as an anti-solvent, enhancing the micromeritic properties of the cocrystal. The addition of dichloromethane (DCM) facilitated the formation of spherical particles via rapid viscous phase transition. Fourier-transform infrared (FTIR) spectroscopy identified significant molecular interactions, such as hydrogen bonding between the ibuprofen carboxyl and nicotinamide acylamino groups, ensuring cocrystal stability. Hot-stage microscopy (HSM) and scanning electron microscopy (SEM) analyses demonstrated that cocrystals exhibited lower thermal stability but improved dissolution rates due to their amorphous-crystalline structures and rough, porous surfaces. Differential scanning calorimetry (DSC) showed altered thermal profiles with a reduction of 7.21°C, indicating modified crystal lattice structures. Powder X-ray diffraction (PXRD) confirmed the formation of new crystalline phases. Micromeritic evaluations revealed favorable particle size distribution (PSD) with an average size of 5 mm, enhanced flowability, and compressibility, with cocrystals showing superior tensile strength (2.36 MPa at 207.97 MPa) and dissolution rates 2.82 times higher than pure IBU at pH 6.8. These findings highlight the potential of the SA-CC method to produce cocrystals with enhanced drug properties, paving the way for improved pharmaceutical formulations. [ABSTRACT FROM AUTHOR]

This study presents a novel method to determine the kinetics of spherical agglomeration in-line via monitoring the stirrer torque. In order to confirm that the torque can be used to characterise the process phases, samples were taken at different times during the agglomeration process and the morphology of agglomerates is examined using X-ray microtomography. It can be shown that if the stirrer torque is decreasing, the fast growth regime starts. Additionally, the influence of binding-liquid concentration as well as the primary particle shape was studied. Both have an influence on the process kinetics as well as on the different growth mechanisms of agglomerates during spherical agglomeration. These two growth mechanisms, distribution and immersion, can be identified by the morphological parameters sphericity, packing density and fractal dimension. In particular, the concept of fractal dimension was not used so far on agglomerates obtained from spherical agglomeration. [ABSTRACT FROM AUTHOR]

BACKGROUND: In this work, a process development study for the crystallization step of dexlansoprazole API has been demonstrated under the Quality‐by‐Design (QbD) paradigm. Dexlansoprazole (crystalline) samples prepared under different crystallization conditions of reactor temperature and addition time of anti‐solvent were subjected to solid‐state characterization with variety of analytical techniques, including X‐ray powder diffraction (XRPD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic vapour sorption (DVS), scanning electron microscopy (SEM), particle size distribution (PSD) by laser diffraction and intrinsic dissolution rate (IDR). RESULTS: The crystalline samples were observed to have identical polymorphic phase integrity but differed in their physical characteristics. The particle size distribution and microscopy data collectively elucidated the particle growth kinetics and the extent of agglomeration could be correlated to crystallization conditions, namely reactor temperature and addition time of anti‐solvent. The intrinsic dissolution rate of samples was in good agreement with the morphological properties. CONCLUSION: An empirical model has been proposed for intrinsic dissolution rate correlating with crystallization process parameters. In conclusion, it was possible to elucidate the impact of crystallization parameters on the solid‐state behaviour of dexlansoprazole for development of appropriate pharmaceutical dosage forms. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

The agglomeration of aluminum during the combustion of solid propellants considerably impacts engine operation and has been widely studied in recent years. The characteristics of aluminum agglomeration in aluminum‐based composite propellants have been studied via experiments and simulations. In this study, the agglomeration process and the characteristics of agglomerated particles are summarized. Agglomeration models and simulation methods have garnered considerable attention because they are not influenced by experimental conditions, are economical, and have minimal restrictions. Therefore, five agglomeration models and four simulation methods are introduced herein to investigate agglom eration in aluminum‐based composite propellants. By analyzing the advantages and disadvantages of these models and methods, deeper agglomeration mechanisms can be explored and new directions for suppressing agglomeration can be identified to mitigate agglomeration issues. These efforts can support and guide the design of solid rocket propellants and the safe operation of rocket engines. [ABSTRACT FROM AUTHOR]

In this study, free‐standing composites consisting of 90 wt% nanoenergetic mesoparticles are fabricated and their combustion characteristics are investigated. The findings reveal that the integrity of the mesoparticles remains intact during the printing process and a reduction in sintering is observed for the composite of mesoparticles compared to the physical mixture. However, the composite of mesoparticles exhibits noncontinuous and oscillating propagation behavior at a steady frequency of ≈5 Hz. This is attributed to insufficient heat feedback from the flame to the unburnt material. To address this issue, carbon fiber (C.F.) is introduced into the composite to enhance heat feedback to the reaction front by intercepting hot agglomerates near the burning surface. Incorporating C.F. leads to steady propagation of the composite. Agglomerate residence time and characteristic heat transfer time analysis near the burning surface indicate that while the composite without C.F. has agglomerate residence time on the same order of magnitude as the characteristic heat transfer time, the composite with C.F. has significantly increased overall agglomerate residence time compared to the characteristic heat transfer time. This confirms the enhanced heat feedback through C.F. inclusion. This study demonstrates the crucial role of heat feedback in the combustion behavior of energetic composites. [ABSTRACT FROM AUTHOR]

Highlights Investigating the effect of nanoparticle dispersion morphology on the properties of the interfacial layer of polymer nanocomposites (PNCs) provides an important theoretical basis for designing and regulating the macroscopic properties of PNCs. Differential scanning calorimetry (DSC) and broadband dielectric spectroscopy (BDS) were used to investigate the characteristic parameters of the interfacial area, segmental dynamics and enthalpy relaxation of PNCs with nanoparticle agglomerates and uniformly dispersed morphology. The volume fraction of the interfacial area (φint) and the extent of influence of the interfacial area on the enthalpy hysteresis reduction (χint) in PNCs with agglomerated nanoparticles are lower than that of PNCs with uniformly dispersed nanoparticles for the same nanoparticle loading. Because of the irregular structure of the nanoparticle aggregate morphology, the linear relationships between φint and nanoparticle content is not valid in PNCs with agglomerated nanoparticles. Interestingly, φint obtained by BDS and χint have a clearly linear relationship in all PNCs, independent of nanoparticle dispersion morphology. Such universal quantitative relationship provides a new research methodology for investigating the characteristic parameters of the interfacial area in PNCs, and facilitates the construction of a correspondence between the microscopic parameters of interfacial area and the macroscopic properties of PNCs. The linear relationships between φint and nanoparticle content are not valid in PNCs with agglomerated nanoparticles. The linear relationships between φint and the decreased degree of ΔHR can be noted in all PNCs, independent of nanoparticle dispersion morphology. The universal correspondence provides a new research methodology for investigating the characteristic parameters of the interface layer in PNCs. [ABSTRACT FROM AUTHOR]

The present work explores a systematic investigation of the microstructural, optical, and dielectric properties of W1−xNixO3 (x = 0, 0.02, 0.04, and 0.06) samples and their application in supercapacitors. The sol–gel auto-combustion process was used to synthesize these samples, and a number of analytical techniques such as x-ray diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy, Raman, Scanning Electron Microscopy (SEM), UV–visible spectroscopy, dielectric measurements, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) were used to characterize them. The Rietveld refined XRD patterns confirm the monoclinic phase with space group P21/n in a single phase. FTIR spectroscopy confirms the functional groups associated with stretching and bending vibrational modes at various wavenumbers. Raman spectroscopy ensures the phase purity of the materials and shows a blue shift with Ni doping. SEM microscopy reveals a uniform surface morphology as well as particle agglomeration at the surface. UV–visible studies reveal a significant decrease in the bandgap (2.13–1.81 eV) as the Ni concentration is increased. Dielectric studies show that as the frequency rises, the dielectric constant decreases and becomes saturated at higher frequencies. The highest value of the dielectric constant (ε') is observed for the 4% Ni-doped WO3 sample. The electrochemical and capacitive properties have been characterized and studied using CV and EIS analysis. Cyclic voltammetry tests were carried out in the range of − 0.2 to 0.8 V with varying scan rates (5–100 mVs−1), exhibiting a significantly large area under the CV curve, hence higher values of specific capacitance. The maximum specific capacitance at a scan rate of 5 mVs−1 for each sample of W1−xNixO3 (x = 0, 0.02, 0.04, and 0.06) is found to be 126.671, 192.31, 278.52, and 128.58 Fg−1, respectively, in 2M KOH electrolyte. Thus, the synthesized samples exhibit potential for application as electrode materials for supercapacitors. [ABSTRACT FROM AUTHOR]

The redistribution of electrons is driven by the electric field at the heterogeneous interface, optimizing the electronic structure of the anode material and improving the reaction kinetics. This optimization contributes to the enhanced sodium storage performance of transition metal selenides with the dual-carbon-confined strategy. [Display omitted] Transition metal selenides (TMSs) stand out as a promising anode material for sodium-ion batteries (SIBs) owing to their natural resources and exceptional sodium storage capacity. Despite these advantages, their practical application faces challenges, such as poor electronic conductivity, sluggish reaction kinetics and severe agglomeration during electrochemical reactions, hindering their effective utilization. Herein, the dual-carbon-confined CoSe 2 /FeSe 2 @NC@C nanocubes with heterogeneous structure are synthesized using ZIF-67 as the template by ion exchange, resorcin-formaldehyde (RF) coating, and subsequent in situ carbonization and selenidation. The N -doped porous carbon promotes rapid electrolyte penetration and minimizes the agglomeration of active materials during charging and discharging, while the RF-derived carbon framework reduces the cycling stress and keeps the integrity of the material structure. More importantly, the built-in electric field at the heterogeneous boundary layer drives electron redistribution, optimizing the electronic structure and enhancing the reaction kinetics of the anode material. Based on this, the nanocubes of CoSe 2 /FeSe 2 @NC@C exhibits superb sodium storage performance, delivering a high discharge capacity of 512.6 mA h g−1 at 0.5 A g−1 after 150 cycles and giving a discharge capacity of 298.2 mA h g−1 at 10 A g−1 with a CE close to 100.0 % even after 1000 cycles. This study proposes a viable method to synthesize advanced anodes for SIBs by a synergy effect of heterogeneous interfacial engineering and a carbon confinement strategy. [ABSTRACT FROM AUTHOR]

Hydrogen reduction for low-grade iron is consistent with carbon neutrality, which can promote product and heat recycling, fostering environmentally friendly. This study focuses on comparing fluidized bed and fixed bed reduction to determine the optimal hydrogen reduction process, and investigates the improvement of the reduction process by pre-oxidation treatment for ilmenite. The results show that the fluidized bed increases the reduction degree by 7.4% compared with the fixed bed at 60 min, 950 °C. It enhances the crystal transformation of FeTiO 3 →FeTi 2 O 5 →Fe, and decreases particle size of reduced iron to remain a suitable fluidized state. Pre-oxidation treatment during fluidized bed reduction can promote the reduction process, resulting in an 8% increase in reduction degree at 800 °C for 40 min. The kinetic analysis reveals that the fluidized bed reduction is mixed controlled by interfacial chemical reaction and diffusion, whereas the fixed bed is solely governed by interfacial chemical reaction. Fluidized bed reduction effectively reduces the total activation energy by 36.0 kJ/mol in comparison with fixed bed. Pre-oxidized ilmenite reduces the two controlling processes by 19.2 kJ/mol and 5.3 kJ/mol, respectively, in contrast to raw ilmenite. This work provides an effective reduction method for complex low-grade iron ore and realizes high-efficiency iron reduction with zero carbon emission. [Display omitted] • Fluidized bed reduction can provide the crystal phase changing. • Reduced products in fluidized bed have pits, cracks and pores to promote mass and temperature transfer. • There are various kinetic controlling steps for fluidized and fixed bed reduction. • Pre-oxidation treatment can accelerate reduction process and decrease activation energy. [ABSTRACT FROM AUTHOR]

Spatially dual-confined Ni-dope CoS 2 @NC@C microrods (Ni-CoS 2 @NC@C) are developed via structural design, heteroatom doping and carbon confinement to boost sodium storage performance of the material. [Display omitted] Currently, conversion-type transition metal sulfides have been extensively favored as the anodes for sodium-ion batteries due to their excellent redox reversibility and high theoretical capacity; however, they generally suffer from large volume expansion and structural instability during repeatedly Na+ de/intercalation. Herein, spatially dual-confined Ni-doped CoS 2 @NC@C microrods (Ni-CoS 2 @NC@C) are developed via structural design, heteroatom doping and carbon confinement to boost sodium storage performance of the material. The morphology of one-dimensional-structured microrods effectively enlarges the electrode/electrolyte contact area, while the confinement of dual - carbon layers greatly alleviates the volume change-induced stress, pulverization, agglomeration of the material during charging and discharging. Moreover, the introduction of Ni improves the electrical conductivity of the material by modulating the electronic structure and enlarges the interlayer distance to accelerate Na+ diffusion. Accordingly, the as-prepared Ni-CoS 2 @NC@C exhibits superb electrochemical properties, delivering the satisfactory cycling performance of 526.6 mA h g−1 after 250 cycles at 1 A g−1, excellent rate performance of 410.9 mA h g−1 at 5 A g−1 and superior long cycling life of 502.5 mA h g−1 after 1,500 cycles at 5 A g−1. This study provides an innovative idea to improve sodium storage performance of conversion-type transition metal sulfides through the comprehensive strategy of structural design, heteroatom doping and carbon confinement. [ABSTRACT FROM AUTHOR]

Electrocatalytic CO2 to multi‐carbon products is an attractive strategy to achieve a carbon‐neutral energy cycle. Single‐atom catalysts (SACs) that achieve the C2 selectivity always have low metal loading and inevitably undergo in situ reversible/irreversible metallic agglomerations under working conditions. Herein, a high‐density Cu SA anchored F, O, N co‐doped carbon composites (CuFONC) with a stable CuN2O1 configuration is provided, which can reach a remarkable C2 selectivity of ≈80.5% in Faradaic efficiency at −1.3 V versus RHE. In situ/ex situ experimental characterization and density functional theory (DFT) calculations verified that the excellent stability of CuN2O1 during the CO2RR process can be attributed to F/O co‐derived regulation for CuFONC. Remarkably, as confirmed by DFT, it is atomic Cu sites and the adjacent bonded N motifs in CuFONC that act as the adsorption sites for CO* during the C─C coupling process. This work brings a prospective on designing novel but stable atomic Cu coordination for electrolytic CO2‐to‐C2 pathway. [ABSTRACT FROM AUTHOR]

In this paper, the dispersion of Carbon nanomaterials (CNMs) in an electrolytic solution containing cations such as Ca2+, Al3+, Na+, and Mg2+ with different types of superplasticizers (Sika, Master Ease 3502, Prime DC, and Prime Flow) have been investigated. Further, the stabilized CNMs along with different superplasticizers (Sps) incorporated into the cementitious mortar and studied their mechanical strength. The influence of Sps on the stability of CNMs in an aqueous medium has been monitored by UV-Visible spectroscopy. The study concludes that Sika Sp was the best dispersant for the CNMs dispersion in an aqueous medium. The de-stability of the CNMs has followed this trend of the agglomerations in the electrolytic solution as Al3+>Ca2+>Mg2+>Na+. The Sika Sp has great dispersant properties as well as provides a homogeneous distribution of CNMs in a cementitious matrix which was supported by FE-SEM analysis. The addition of SIKA@PPC-GO (GO about 0.0015% by weight of cement) and SIKA@PPC-FCNTs (FCNTs about 0.0015% by weight of cement) results in enhancement of cement 11.67%, 8.73% for compressive and 26.35, 20.61% for tensile strength respectively, at the curing ages of 90 days. This investigation may provide advanced knowledge to predict the stability of CNMs in superplasticizer-based solutions. [ABSTRACT FROM AUTHOR]

The formulation fundamentally determines the combustion characteristics and agglomeration behavior of propellants. This study compared the effects of four factors on the combustion, agglomeration, and combustion efficiency of nitramine solid propellants: the aluminum size, the ammonium perchlorate size, the nitramine size, and the mass ratio of ammonium perchlorate to nitramine. The comparison was conducted through a series of experimental methods including burning rate tests, collection of the condensed-phase combustion products, chemical titration, and physicochemical analysis. In terms of burning rate, reducing the particle sizes of aluminum powder and ammonium perchlorate, increasing the nitramine size, and increasing the mass ratio of ammonium perchlorate to nitramine all effectively enhance the burning rate. The influence of these four factors on burning rate, in descending order of impact, is: the mass ratio of ammonium perchlorate to nitramine > the ammonium perchlorate size > the aluminum size > the nitramine size. Regarding agglomeration and combustion efficiency, increasing the particle sizes of aluminum and nitramine, increasing the mass ratio of ammonium perchlorate to nitramine, and decreasing the ammonium perchlorate size can effectively inhibit agglomeration and enhance combustion efficiency. Among these, the ammonium perchlorate size has the greatest effect on enhancing the combustion efficiency, potentially increasing it by 16%. The nitramine size has the weakest impact on combustion efficiency, with a potential increase of 5.5%. The experimental results of this study can provide references for a deeper understanding of the combustion mechanisms of nitramine solid propellants, the establishment of combustion models, and the realization of formula optimization. • Formulation effect on combustion and agglomeration of propellants are studied. • The mass ratio of AP to nitramine has the greatest effect on the burning rate. • The AP size has the greatest effect on enhancing the combustion efficiency. • The comprehensive mechanism of formulation on propellants is proposed. [ABSTRACT FROM AUTHOR]

The impacts of thermal treatment on the precipitate morphology and oxidation behavior of a dual-phase (FCC + L12) multi-principal element alloy (MPEA), Ni45Co17Cr14Fe12Al7Ti5, was studied at 1000 °C via isothermal and cyclic testing. Thermogravimetric analysis and subsequent characterization revealed that smaller precipitates had an increased capacity to form protective sub-surface oxide layers which mitigated total mass gain. The smaller-precipitate-containing samples exhibited a decrease in thickness of the primary Cr2O3 scale and parabolic growth rate. Mechanistically this behavior is believed to stem from the increased growth rate of initial Al2O3 nuclei and decreased inter-precipitate spacing which results in faster lateral diffusion and agglomeration. [ABSTRACT FROM AUTHOR]

This work focuses on the enhancement of removal performance of TiO2 by the introduction of trace amout of GO composite. Among various synthesis methods, it was found that the GO–doped TiO2 by microwave-assisted hydrothermal method had the highest performance in the improvement for Cr (VI) treatment. The removal rate of Cr (VI) by TiO2–GO (0.05%) was 95.96% which is 13.58% higher than that of TiO2. It can be confirmed that GO was successfully doped on TiO2 by XRD, XPS, and FT-IR characterizations. In addition, SEM, TEM, N2 adsorption isotherm, UV–Vis spectra, and photocurrent response elucidate the mechanism of potency enhancement. The addition of trace GO reduces the particle size of TiO2 and results in the agglomeration phenomenon of TiO2, so that the specific surface area of TiO2 becomes larger and the distribution is more uniform, which expands the photoresponse range, and elevating the photoelectron response. Thus, the absorption ability of visible light is greatly improved. The reported method provides a more economical option for treating Cr(VI) wastewater. [ABSTRACT FROM AUTHOR]

Agglomeration economies can bring about positive externalities, while excessive agglomeration backfires. However, existing literature on place‐based policies mainly focuses on policies that enhance agglomeration economies. Few studies discuss dispersion policies coping with the negative externality from excessive agglomeration. Owing to the unclear effects of dispersion policies, we conduct empirical research on the noncapital function relief (NCFR) policy, which is implemented to decrease the agglomeration in Beijing, the capital of China, and promote the development of surrounding areas. Exploiting the difference‐in‐difference model, we find that the NCFR policy implementation significantly facilitates the economic growth of the surrounding areas of Beijing. Changes in the distribution of new firm entry and population are two main channels, while no significant effect on the productivity is found. Furthermore, areas that are less‐developed could benefit more from the NCFR policy. Our findings may enlighten other developing countries in urban economic management. [ABSTRACT FROM AUTHOR]

Since solid propellants can significantly increase the mobility, load, and range of missile weapons and equipment when used as a power source, energy performance is always the primary focus of solid propulsion technology development. This paper investigated differences in the agglomeration of aluminum (Al) and characteristics of the burning surface of nitrate ester plasticized polyether (NEPE) propellants and hydroxyl-terminated polybutadiene (HTPB) propellants. The experiments were conducted under a 0.1 MPa argon gas atmosphere using a high-speed camera combined with a telephoto microscope head (macro lens). In comparison with HTPB propellants, it was discovered that the agglomeration process of Al particle of NEPE propellants had two modes. Al aggregates exit the burning surface after growing into nearly spherical agglomerates in Mode A, which is comparable to HTPB propellants. Unique to NEPE propellants, Mode B is where the Al particles aggregate into massive coral-like structures. Three factors could account for this discrepancy. First, since NEPE propellants include less ammonium perchlorate (AP), the AP is less likely to form a pocket structure. It keeps the Al particles in a large "pocket" resembling the burning surface and provides advantages for their ability to aggregate. Second, NEPE propellants have a thicker molten layer on the burning surface. It has a capillary force impact on the Al particles on the burning surface and promotes interaction between Al particles. Finally, NEPE propellants create a clear skeleton layer on the burning surface that helps Al particles stay on the burning surface. A microscopic multi-flame combustion model was created to describe the makeup of the flame of NEPE propellants. It includes the AP unit flame, the CL-20-AP flame, the Al combustion flame, and the diffusion flame of the products of decomposition of each component. In this study, the existence of molten layer and skeleton layer on the burning surface of NEPE propellants was observed for the first time in experiments. It contributes to the understanding of the unique agglomeration behavior of aluminum particles of NEPE propellants and provides theoretical guidance for the directional regulation of aluminum particle agglomeration characteristics. [ABSTRACT FROM AUTHOR]

Hydrogen (H 2) is a significant alternative energy supply due to its outstanding and potentially useful properties, promoting sustainable development. Photocatalytic H 2 generation from H 2 O employing inexhaustible and naturally abundant solar power on semiconducting photocatalysts is a promising and sustainable approach. Yet, particle aggregation/agglomeration, insufficient solar-light absorbance capacity, and quick photo-excited charge carriers' recombination are the main deficiencies in most current photocatalytic systems. This investigation intends to fabricate mesoporous YVO 4 nanosheets through a facile hydrothermal process, employing polyvinyl alcohol polymer as a structural directing agent to prevent agglomeration. Moreover, for the first time, varied tiny contents of platinum oxide (PtO) ranging from 0.3 to 1.2 wt%, were decorated on YVO 4 , constructing p-n PtO-YVO 4 heterojunctions. The fabricated catalysts were characterized via advanced instruments and applied to H 2 production using visible light energy. It was found that the physicochemical characteristics of the designed catalysts revealed the influence of loading PtO on the surface, structure, light absorbance features, charge separation, and efficacy. The loading of 0.9 wt% PtO on YVO 4 has barely lowered the surface area (SA) from 187 to 176 m2/g. In contrast, the visible wavelength uptake is notably extended owing to the substantial energy bandgap narrowing from 3.40 to 2.11 eV. The visible-light-evolved hydrogen on 0.9 wt% PtO-YVO 4 amounted to 34.76 mmol g−1. Moreover, this novel sample demonstrated a 99.88% recycling capacity after five cycles. This efficacious photocatalytic H 2 generation is due to extensive light sensitivity and the rapid charge separation and migration between PtO and YVO 4 following the p-n heterojunction mechanism. [Display omitted] [ABSTRACT FROM AUTHOR]

Boronized Ti6Al4V/FHA composites were prepared by microwave sintering of mixed powders of Ti6Al4V, TiB 2 , and synthesized fluorine-substituted hydroxyapatite (FHA) with variable compositions at 1050 °C for 30 min. The unique "lens effect" of microwave facilitated the in-situ transformation of nanoscale TiB 2 into TiB, serving as the reinforcing phase within the composites. Increasing the theoretical fluorine substitution percentage of FHA from 0% to 50% caused less thermal decomposition of hydroxyapatite during sintering, promoting densification and thereby mechanical properties of the composites. However, elevating the substitution percentage to 100% led to excessive grain growth and FHA agglomeration, deteriorating the composite mechanical performance. The boronized Ti6Al4V/FHA composite produced using FHA with the theoretical fluorine substitution of 50% exhibited the highest compressive strength (397.7 MPa), proper compressive modulus (10.65 GPa) and maximum microhardness (385.3 HV). Furthermore, it showed excellent hydrophilicity and good cell adhesion, confirming its superior bioactivity for dental applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Fiber is highly escapable in conventional slickwater, making it difficult to form fiber-proppant agglomerate with proppant and exhibit limited effectiveness. To solve these problems, a novel structure stabilizer (SS) is developed. Through microscopic structural observations and performance evaluations in indoor experiments, the mechanism of proppant placement under the action of the SS and the effects of the SS on proppant placement dimensions and fracture conductivity were elucidated. The SS facilitates the formation of robust fiber-proppant agglomerates by polymer, fiber, and quartz sand. Compared to bare proppants, these agglomerates exhibit reduced density, increased volume, and enlarged contact area with the fluid during settlement, leading to heightened buoyancy and drag forces, ultimately resulting in slower settling velocities and enhanced transportability into deeper regions of the fracture. Co-injecting the fiber and the SS alongside the proppant into the reservoir effectively reduces the fiber escape rate, increases the proppant volume in the slickwater, and boosts the proppant placement height, conveyance distance and fracture conductivity, while also decreasing the proppant backflow. Experimental results indicate an optimal SS mass fraction of 0.3%. The application of this SS in over 80 wells targeting tight gas, shale oil, and shale gas reservoirs has substantiated its strong adaptability and general suitability for meeting the production enhancement, cost reduction, and sand control requirements of such wells. [ABSTRACT FROM AUTHOR]

Modeling of CO2 removal in a rotating packed bed using a mixed amine solution of piperazine and methyldiethanolamine with various molar concentration ratios was done with Aspen Plus® and dynamically linked with Intel® Visual Fortran. In addition to the mass and energy balances, all the necessary correlations for the rotating packed bed were written in Intel® Visual Fortran. The developed model was validated, and the result showed good agreement with a percentage error of less than 10%. The model was scaled‐up to absorb CO2 from the flue gas composition of a typical 6.4 MWe biomass power plant with the goal of producing net negative CO2 emissions. The effect of process parameters such as temperature, rotation speed, liquid‐gas ratio, methyl diethanolamine concentration, and piperazine concentration on capture efficiency and regeneration energy was investigated. It was discovered that increasing the rotational speed results in an improvement in the separation efficiency. Increasing the temperature of the lean solvent causes a decrease in separation efficiency, which is due to a decrease in solubility as the temperature increases. Increasing the liquid‐to‐gas ratio leads to an increase in CO2 absorption efficiency because more hydroxide ions are present to react with the CO2. Piperazine is a reactive compound and increasing its concentration in the mixed solvent leads to an increase in CO2 absorption efficiency. Finally, the results of the study demonstrated that a solvent mixture consisting of piperazine and methyldiethanolamine has the potential to be utilized in post‐combustion CO2 capture using rotating packed bed technology. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A better understanding of the changes in binder chemistry and microstructure triggered by aging is fundamental as it increases the cracking susceptibility of asphalt materials and reduces pavement durability. In this context, this paper presents the findings of a collaborative study that delves further into the alterations in binder chemistry, microstructure, and rheology of laboratory – and field-aged binders using innovative experimental and fundamental theory techniques. An increase in polarity leading to a shift in the apparent molecular weight distribution (AMWD) towards higher molecular weights, which implies molecular agglomerations, could be observed as a result of aging via Saturates, Aromatics, Resins, and Asphaltene Determinator (SAR-AD) and Size Exclusion Chromatography (SEC), respectively. As for the theoretical methods, the δ-method and Molecular Agglomeration Index (MAI) that estimate the AMWD and incidence of molecular agglomeration, respectively, show satisfactory relationship with the SAR-AD and SEC results. This reinforces the soundness of the δ-method and MAI. [ABSTRACT FROM AUTHOR]

Based on the calculation of interaction force between particles, the analysis of interfacial agglomeration microstructure, the analysis of agglomeration reorganization process and the calculation of equilibrium force acting on particles, the oscillation behavior of particles with different hydrophobicity after the coalescence of bubble and particle monolayer at gas-liquid interface was systematically studied by using a modified L-B trough and a high-speed dynamic microscopic test device. The results showed that, with the same adsorption density of interfacial particles, dense aggregates were formed more easily for the particles with low hydrophobicity (contact angle = 43°), while the aggregates formed by the particles with high hydrophobicity (contact angle=75°) were looser. The interface oscillation can be induced by the coalescence of bubble and particle monolayer. Under this effect, the agglomerates on the interface were continuously reorganized under the influence of the surface pressure gradient and the oscillation wave, and finally the dispersion of the interface particles became more uniform, which was very similar to the Gibbs-Marangoni effect of stabilizing the liquid film by foaming agent molecules. The horizontal drag force, inertia force and the interaction force between particles played a key role in the process of interfacial agglomeration reorganization. Under the same test conditions, the instantaneous velocity and the mean square displacement (MSD) of the particles with low hydrophobicity were significantly larger than those of the particles with high hydrophobicity due to the additional vertical upward capillary force, which means that the oscillation intensity of particles with low hydrophobicity was more intense, the amplitude was larger, and the desorption probability was higher. [ABSTRACT FROM AUTHOR]

Polymer agglomeration is a useful way to enlarge the particle size of polybutadiene latex (PBL). However, the agglomeration process is very complex and is affected by many factors. Therefore, it is difficult to predict the mean particle size and distribution of agglomerated PBL. This study proposed a novel simulation method based on the artificial neural network (ANN) model. Firstly, the influence of agglomeration conditions on the particle size of agglomerated PBL were investigated, including the particle size of pre‐agglomerate PBL, the amount, the α‐methacrylic acid (α‐MAA) content, the solid content and the particle size of agglomerating agent. It is found that these factors have a close nonlinear relationship with the mean particle size and polydispersion index (PDI) of agglomerated PBL. Then, a model containing 236 data points was built using ANN including these properties as input with mean particle size and PDI of agglomerated PBL as output. The coefficient of determination (R2) values predicted by ANN for training, validation, test and total data are 0.9879, 0.9964, 0.9930, and 0.9902, respectively. It indicates that there is a good agreement between experimental data and predicted results by ANN. This study demonstrates that a simple machine learning method has good performance in predicting the particle size of agglomerated PBL, which further improves the development efficiency of PBL polymer agglomeration. [ABSTRACT FROM AUTHOR]

We have obtained straight-line-shaped agglomeration grooves of 2~3.5 μm width in the ~60-nm-thick Si thin films by the continuous-wave laser crystallization (CLC) when the laser power is increased above the optimum power to obtain grain boundary-free (GB-free) films. The GB-free CLC is suitable for fabricating monolithic three-dimensional integrations. The grooves are formed in the Si film vertically from the Si surface to the underlying insulating substrate, and a hump of the Si film is generated along the edge of the groove at the retarded side of the scan. In situ observation of the crystal growth shows that the grooves originate from voids, which happen to be generated by agglomeration in the melt zone. The voids move at a constant velocity, Vvoid , within the melt zone. The melt zone moves at the scan velocity, V, to the scan direction. The void velocity, Vvoid , is obtained from the angle of the groove line to the scan direction, and is found to be proportional to V−0.5. [ABSTRACT FROM AUTHOR]

Based on the land economic density of 892 town units, the spatial pattern of the land economic density in Zhejiang Province is analyzed using the coefficient of variation, spatial classification, and spatial correlation methods, and the influencing factors are analyzed using a spatial regression model. The results are as follows: (1) The coefficients of variation were 2.6 and 3.1 in 2014 and 2019, respectively, indicating that the degree of imbalance of the town's industrial economy at the county level increased. (2) The distribution of the high-level agglomeration areas was characterized by one core area and two sub-core areas. The main core area was located at the junction of Hangzhou City, Shaoxing City, and Jiaxing City, and the two sub-core areas were located in Yuyao City and the main urban area of Ningbo City. In addition, several small-scale agglomeration areas composed of medium and high-level units were distributed in Wenzhou City. (3) The high-value agglomeration and low-value agglomeration distribution in the spatial correlation patterns was identified using the spatial auto-correlation method. The hot spots and sub-hot spots were distributed in Northern Zhejiang, and the cold spots formed a large-scale agglomeration in Quzhou City, Lishui City, Taizhou City, and several other cities in Southern Zhejiang. (4) Compared with the county scale, the spatial scope of the high-level areas in Northern Zhejiang shrunk significantly at the township scale, and the high-level agglomeration areas along the southeast coast changed into a cluster of several townships. (5) According to the geographically weighted regression (GWR) model, the importance of influencing factors is as follows: population density > regional area > industrial output value per capita > total population > proportion of secondary and tertiary personnel > total employees. [ABSTRACT FROM AUTHOR]

Herein, the spatial evolution characteristics of high-level Grade A tourist attractions in the Yangtze River Delta (YRD) urban agglomeration, from 2001 to 2021, are studied by comprehensively applying the nearest neighbor index, kernel density analysis, standard deviation ellipse, and spatial autocorrelation. High-level Grade A tourist attractions are investigated using the random forest model as the driving mechanism of the spatial pattern. Results show that 1) the spatial distribution of high-level Class A tourist attractions in the YRD city cluster has grown to be an agglomeration, and the high-density areas have evolved from "point-like dispersion to regiment-like combination," gradually forming a B-shaped core density structure. 2) The spatial distribution comprises an overall "northwest–southeast" direction, a small counterclockwise rotation, the distribution of the center of gravity to the southwest migration, and the center of gravity from the territory of Suzhou City to the territory of Huzhou City. 3) The high-level Class A tourist attractions in the YRD city cluster as a whole show a strong positive spatial correlation, and the significantly clustered areas include three types: high-high (H-H), low-low (L-L), and low-high (L-H). 4) The spatial distribution of high, A-level tourist attractions in the YRD city cluster results from the combined action of the natural environment, resource endowment, socioeconomy, and policy background. Each element has a nonlinear and complex influence on the distribution of scenic spots. [ABSTRACT FROM AUTHOR]

Pulverized coal pyrolysis based on solid heat carrier has a huge advantage in high tar yield. In this study, pyrolysis experiments on pulverized coal were conducted in a lab-scale fluidized bed reactor at 650 °C, utilizing char as the solid heat carrier. The influence of mass ratio of char to coal (RATIO) was investigated. Results show that the incorporation of solid heat carrier of char significantly enhanced the primary pyrolysis reaction in coal pyrolysis, resulting in increasing yields of tar and gas but reducing one of char. The yield of tar maximally reached 148.80–262.22% of the Gray–King analysis value at the RATIO of 14.52 g/g. As the RATIO increased, the tar contained more light component content, indicating that incorporating solid heat carriers improved the tar quality. These findings offer significant insights for the design of fluidized bed pyrolysis unit utilizing char as solid heat carrier. [ABSTRACT FROM AUTHOR]

Ti3C2Tx MXene, as a common two-dimensional material, has a wide range of applications in electrochemical energy storage. However, the surface forces of few-layer or monolayer Ti3C2Tx MXene lead to easy agglomeration, which hinders the demonstration of its performance due to the characteristics of layered materials. Herein, we report a facile method for preparing monolayer Ti3C2Tx MXene on nickel foam to achieve a self-supporting structure for supercapacitor electrodes under high electrostatic fields. Moreover, the specific capacitance varies with the deposition of different-concentration monolayer Ti3C2Tx MXene on nickel foam. As a result, Ti3C2Tx/NF has a high specific capacitance of 319 mF cm−2 at 2 mA cm−2 and an excellent long-term cycling stability of 94.4% after 7000 cycles. It was observed that the areal specific capacitance increases, whereas the mass specific capacitance decreases with the increasing loading mass. Attributable to the effect of the high electrostatic field, the self-supporting structure of the Ti3C2Tx/NF becomes denser as the concentration of the monolayer Ti3C2Tx MXene ink increases, ultimately affecting its electrochemical performance. This work provides a simple way to overcome the agglomeration problem of few-layer or monolayer MXene, then form a self-supporting electrode exhibiting excellent electrochemical performance. [ABSTRACT FROM AUTHOR]

The combination of hollow micromorphology and graphene anchoring effectively alleviate the volume changes during cycling, greatly improves the electronic conductivity and inhibit the agglomeration and pulverization of the material, the H-VO 2 @GO exhibits excellent electrochemical properties. [Display omitted] Vanadium dioxide-based materials have been proved to be promising cathodes for aqueous zinc ion batteries (AZIBs) due to their cost-effectiveness and high theoretical specific capacity; nevertheless, the low electronic conductivity and poor cycle stability restrict their application. Herein, hollow VO 2 microspheres anchored on graphene oxide (H-VO 2 @GO) are synthesized via a facile simple hydrothermal reaction as high-performance cathodes for AZIBs. The hollow micromorphology of the material provides a large specific surface area and effectively alleviates the volume changes during cycling, while the anchoring of VO 2 on graphene oxide greatly improves the electronic conductivity and inhibits the agglomeration and pulverization of the material. Resulting from the combination of unique micromorphology and graphene oxide anchoring, the as-prepared H-VO 2 @GO exhibits the impressive specific capacity of 400.1 mAh/g at 0.5 A/g and excellent cycling performance with 96.1 % of capacity retention after 1500 cycles at 10 A/g. This investigation provides a use reference for designing high-performance cathodes materials for AZIBs by optimizing the microstructure of electrode materials. [ABSTRACT FROM AUTHOR]

Here in the present work, simple, eco-friendly and economical method of synthesis has been approached known as hydrothermal synthesis that allowed easy doping of Fe ions into the ZnS host lattice. A unique approach was adopted for the first time to prepare ZnS material where thioglycolic acid (TGA) was used as a source for sulfur in addition to a reducing and capping agent. Properties of the nanostructures were explored using different techniques. The X-ray diffraction (XRD) results indicated formation of single phase hexagonal ZnS material where inclusion of Fe2+ ions into the ZnS lattice have no influence on the crystal phase of the material. Probably almost identical sizes of Zn2+ and Fe2+ ions made this possible that indicated Fe2+ ions take Zn2+ vacant sites by substitution of Zn2+ ions by Fe2+ ions. Chemical analysis (X-ray photoelectron spectroscopy) performed discovered that Zn and Fe ions were present in +2 oxidation states whereas S is in −2 state. Anisotropic growth of the nanostructures is reported where irregular shaped nanostructures of varying dimensions were formed that agglomerated as doping concentration was increased to form spherical microstructures. Inclusion of Fe ions into the host material modified magnetic behavior of the nanostructures converting diamagnetic ZnS into a ferromagnetic material. Optical properties were also influence by the doping resulting in photon absorption at different wavelengths. The band gap got reduced from 3.2 eV to 2.7 eV making the ZnS nanostructures visible light active. The nanostructures with band gap 2.7 eV exhibited good photocatalytic activity against methylene blue (MB) dye under visible light illumination degrading 94% of the dye in just 2 h. The scavenging experiments performed showed hydroxyl free radicals play an active role in mineralizing the dye. Reusability and post photocatalytic properties of the photocatalysts determined their stability and potential ability for possible commercialization. [ABSTRACT FROM AUTHOR]

Urbanization is an important factor in promoting socio-economic development and influencing regional ecological security patterns, and the stable coordination of the ecological environment and urbanization is a guarantee of achieving sustainable regional development. In order to balance the coupling coordinated relationship between urbanization and ecological environment in the urbanization development process of urban agglomerations, the 23 counties of Changsha-Zhuzhou-Xiangtan urban agglomeration were taken as the research object, the land use, nighttime lighting and MODIS data were comprehensively collected; based on Google Earth Engine (GEE) platform, the nighttime lighting index and remote sensing ecological index were constructed to characterize the level of urbanization and ecological environment quality respectively from 2002 to 2022, and the coupling coordination degree model was used to analyze the hierarchical clustering and spatial-temporal differences of the coupling coordination between urbanization and ecological environment in Changsha-Zhuzhou-Xiangtan urban agglomeration. The results show that (1) from 2002 to 2022, the Changsha-Zhuzhou-Xiangtan urban agglomeration experiences a significant change in heat, decreasing by 29.26%; and the ecological quality of counties, except for Yanling county, decrease to different degrees, showing an inverted N-type or M-type trend, with the greatest decrease in remote sensing ecological indexes in Kaifu district, Tianxin district, Tianyuan district and other counties, where there are many urban construction activities; (2) the urbanization level of Changsha-Zhuzhou-Xiangtan urban agglomeration increases, and the nighttime lighting index is on the rise overall, but the growth rate in 2022 is lower than that in 2017, the development between counties is uneven, and the counties with higher levels concentrate in Changsha; (3) most counties in Changsha-Zhuzhou-Xiangtan urban agglomeration are in the stage of transition from antagonism to friction from 2002 to 2022, and the overall coupling degree is at a high level in 2012, but 17 counties fall back to a lower stage in 2017. In 2022, most counties in Changsha-Zhuzhou-Xiangtan urban agglomeration have reached a state of harmonization in terms of the coupling degree of coordination, and some counties are out of harmony for a long period, and the overall coupling and coordination situation are better, but the spatial distribution is unbalanced, with the characteristics of high in the north-central part and low in the south. [ABSTRACT FROM AUTHOR]

In this study, we report on the electrochemical properties of hydrothermally synthesized MoS2 composites for use in lithium-ion batteries. A widespread method was modified for facile synthesis of pristine MoS2 and its composites with PEDOT:PSS, rGO, or both. The electrochemical performance of the materials was investigated using cyclic voltammetry and galvanostatic charge-discharge measurements. The addition of rGO significantly enhances the specific capacity and stability of MoS2, with the MoS2/rGO composite exhibiting specific capacity in the second cycle of 748 mA·h·g−1 and a capacity retention of 63% through the 400th cycle. The composites exhibited a phenomenon of capacity increase after reaching a minimum, with this effect being most pronounced in the case of MoS2/rGO. This composite reached its lower capacity value at the 143rd cycle (211 mA·h·g−1), and then recovered to 224% of the minimum capacity (472 mA·h·g−1). We attribute this behavior to an increase in the availability of active particles over the course of cycling by milling the active components into smaller and thus more accessible species of Li2S and S. The intensity of the effect of rGO is due to its intrinsically large surface area and two-dimensional layered structure, which enhances the distribution of redox-active particles within the material layers and prevents agglomeration. Our results contribute to the existing evidence of the improved electrochemical performance of MoS2 in Li-ion batteries with layered graphitic compounds and provide promising avenues for further research of the unique behavior of conversion materials. [ABSTRACT FROM AUTHOR]

Due to the rapid development of cities and the intensification of human activities, anthropogenic heat emissions play an important role in the impact of urban thermal environment, which is an important factor in causing the urban heat island effect. Analyzing the spatiotemporal distribution characteristics of anthropogenic heat is of great significance for achieving sustainable urban development. The anthropogenic heat flux is divided into four categories of heat flux emissions based on energy type: industry, transportation, building, and metabolism, and anthropogenic heat flux data are calculated for each province in China from 2000 to 2020. The fitted equations for nighttime lighting data and anthropogenic heat fluxes were then constructed through a Geographically and Temporally Weighted Regression (GTWR) model. The spatial distribution of anthropogenic heat fluxes at 500 m resolution were simulated for 2000-2020 in China. The results show that from a spatial perspective, the anthropogenic heat flux in the eastern coastal area is the highest, and the anthropogenic heat flux shows a downward trend from the eastern region to the central and western regions. The high growth type and high level of anthropogenic heat flux are mainly distributed in the eastern region, while the low growth type and low level of anthropogenic heat flux are mainly distributed in the western region. Among the eight major urban agglomerations, Shanghai-Nanjing-Hangzhou and the Pearl River Delta have the most significant growth in anthropogenic heat flux, with the highest proportion of high-level heat flux. In terms of time, the anthropogenic heat flux in China increased from 0.924 W/m2 in 2000 to 1.783 W/m2 in 2020, with an annual growth rate of 4.56%. The anthropogenic heat flux emissions are showing an increasing trend. [ABSTRACT FROM AUTHOR]

The understanding of complex fluidization hydrodynamics and chemical reactions in biomass fast pyrolysis fluidized bed reactors is lacking and requires further investigation. It is urgent to develop accurate mathematical models capable of describing the complex multiphase reaction system of biomass pyrolysis. A comprehensive multiscale model based on coarse‐grained discrete element method (DEM)‐computational fluid dynamics (CFD) was developed in open‐source MFiX code. It incorporates detailed biomass pyrolysis kinetics and an intraparticle model. To validate the model, measurements were conducted in a fluidized bed pyrolyzer, including quantifying the segmental pressure drop along the height of the bed and determining the yields and compositions of gas, liquid, and solid products. The particle mixing and segregation, axial distribution and residence time, Lacey index, and pyrolysis products were investigated. The study provides experimental and theoretical foundations for designing multiphase fluidized bed reactors and advancing biomass thermochemical conversion. [ABSTRACT FROM AUTHOR]

We evaluated the effect of O atoms on the postannealed BaSi2 films grown by molecular beam epitaxy. Postannealing (PA) in an Ar atmosphere at a pressure of 1.9 × 105 Pa increased the O concentration to 7 × 1020 cm−3 in the bulk region and further increased to ∼1022 cm−3 at the BaSi2/Si interface. Cracks formed during the PA process, allowing O to enter more easily to the BaSi2 films. In the x-ray photoelectron spectroscopy spectrum of the Si 2s core level measured at 10 nm from the surface, a shift of the peak related to SiOx was detected, indicating a change in the bonding state of Si and O in this region. When PA was performed in vacuum at 10−3 Pa, the photoresponsivity in the short wavelength region was enhanced, with a maximum value of 6.6 A W−1 at 790 nm. The O concentration in the film decreased in the sample annealed in vacuum, and the PL peak intensity at 0.85 eV decreased, suggesting that this was due to a decrease in O-related defects compared to the Ar atmosphere. However, agglomeration of BaSi2 caused significant surface roughness, indicating the importance of PA conditions that minimize O uptake and keep the surface smooth for improved performance of BaSi2 solar cells. [ABSTRACT FROM AUTHOR]

We report an ohmic contact metallization scheme for n-GaN based on a Re–Al–Ni–Au multilayer stack that offers low-resistivity and provides better edge sharpness and lower surface roughness at reduced annealing temperature compared to standard Ti–Al-based metallization. We studied three sets of samples with Re thicknesses of 10, 30, and 60 nm and measured specific contact resistances using the circular transmission line method. We obtained reliable ohmic contacts with specific contact resistance of the order of 10−6 Ω cm2 at 550 °C temperature with the contact stack having a large annealing temperature window of >300 °C for resistivity below 5 × 10−6 Ω cm2. The lowest contact resistivity, below 10−7 Ω cm2, is achieved at annealing temperature around 650–700 °C. A reduction in surface roughness by a factor of 4, with excellent edge definition for Re >30 nm thickness is observed as compared to Ti–Al contacts. Grazing incidence x-ray diffraction and electron dispersive x-ray spectroscopy (EDS) show intermetallic phases of RexNy, Re–Al–Ni, Al–Re, and Al–Au being formed. Atomic force microscope and EDS measurements show the formation of crystalline Re–Al–Ni agglomerates, surrounded by phases of AlAu2 and Al2Au5. The presence of Re seems to suppress the formation of viscous AlAu4 phase, thus minimizing the lateral flow of the metals and providing better edge acuity. The temperature dependence of contact resistivity suggests a field-emission mechanism for current transport across the contact. Our results show that Re-based ohmic contacts, with their lower annealing temperature and excellent edge definition, may offer a promising alternative to Ti–Al contacts. [ABSTRACT FROM AUTHOR]

In this work, pineapple leaf fiber (PALF) and ramie hybrid fiber‐reinforced epoxy composite samples were evaluated for their hardness strength and resistance to dry slide wear and air jet erosion. Primary reinforcement using the hybrid material was chosen from different lengths (10, 15, 20, and 25 mm) and weight percentages (10%, 20%, 30%, 40%, and 50%). The hardness strength of the hybrid composite varied from 74 to 97 Shore D hardness strength. A dry sliding wear test was conducted with the key parameters of load (20, 30, and 40 N), time (20, 10, 7 min), and speed (160, 320, and 479 rpm). By using the data analyzing software, Taguchi optimization method, the key contribution parameters were identified. In the air jet erosion experiment, impact angle (45°, 60°, and 90°), erodent velocity (28, 41, and 72 m/s), and discharge rate (1, 2.5, and 3.3 g/min) parameters were used. Fiber and matrix materials agglomeration effect and bonding behavior were identified by using the scanning electron microscope (SEM) images. The 20 mm length with 30% of the PALF and ramie hybrid fiber‐reinforced composite sample achieved high hardness strength (97 shore D) and created a high resistance toward wear and erosion studies. Highlights: Natural plant pineapple leaf and ramie fibers are mixed with an epoxy matrix.Used Taguchi analysis to determine the means and signal‐to‐noise ratiosDifferent weight percentages of the PALF and ramie hybrid compositesDry sliding wear and air jet erosion studies are conducted.Individual parameter contributions were identified. [ABSTRACT FROM AUTHOR]

CILRT is an important work in the overhaul of nuclear power plants. VOCs from paints and cleaners used in the containment during the overhaul will migrate inside the containment, and the numerous rooms and compartments inside the containment make the air flow impeded, and the VOCs may be enriched to bring combustion risk. The complete fire risk analysis method includes volatilization kinetics of chemicals, mixture explosion limits, and numerical simulation of VOCs diffusion and migration. The volatilization rate at the lowest room temperature of 20°C is used as a conservative input, the complement of CAITA realistic model is used as the flow domain, and the geometry is appropriately simplified, and the steady ventilation process, the internal flow and the laws of diffusion and agglomeration of 12 kinds of VOCs gases in the 9-h pressure-holding process are investigated by Computational Fluid Dynamics. The simulation results of steady ventilation show that the VOCs gases are almost uniformly carried by the air to all spaces inside the containment, and the explosion risk is low. The concentration field of the steady ventilation process was taken as the initial boundary condition and unsteady state simulation of the 9-h holding pressure process was performed. The results show that the gas flow inside the containment basically stops after 3456 s of pressure holding. With the extension of time, the VOCs gases accumulate at the bottoms of the three lower layers of the containment under the effect of laminar diffusion and gravitational settling, where the total concentration of the mixed gases reaches the highest at the bottom of the lowest layer. The total concentration of the VOCs gas mixture was below the lower explosion limit throughout the 9-h pressure-holding process, and the explosion risk was low. [ABSTRACT FROM AUTHOR]

Polyindole (PIN) has been one of the rising promising conducting polymers of this decade, attracting researchers' attention worldwide. This can be attributed to better redox activity and physicochemical stability. Several techniques had reported synthesis of PIN in organic and aqueous media. However, it has been always reported as difficult. Challenges such as mixed morphology, irregular particle size and undesired agglomeration are among several outcomes' researchers face. Hence, for the first time we present hydrotopically engineered chemical oxidative polymerisation of indole in the presence of Vanadium selenide (VS) in aqueous media. A hydrotrope is a compound that enhances the aqueous solubility of organic compound. The resulting nanocomposite was comprised of decorated polyindole over self-assembled 1D vanadium selenide, giving a 3D sheet like structure, as evident from FESEM studies. The results also highlighted uniform decoration of PIN over the background of VS. Besides, the physicochemical interaction between PIN and VS had been validated using Fourier transform infrared (FTIR) and XRD analysis. Furthermore, electrochemical studies through cyclic voltammetry, galvanic charging discharging techniques for the nanocomposite revealed improved specific capacitance of PV (w.r.t VS) as evidenced from the higher voltametric output current than VS. Electrochemical impedance also corroborated the superior charge transfer at lower frequencies, suggesting the real time applications of the nanocomposite. Lastly, to compliment the electrochemical performance, the nano composite was also used in fabrication of asymmetric super capacitor, which was used to illuminate LED and power a digital stopwatch to augment the conductivity and real time charge storage ability of the as synthesised nanocomposite. To the best of our knowledge, synthesis of PV nano composite using hydrotrope – tetra n-octyl ammonium bromide in aqueous medium can be a promising electrode material for fabrication of super capacitor, resulting in a synergistic enhancement of vanadium selenide using PIN. [ABSTRACT FROM AUTHOR]

This research presents the structural, microstructural, Raman, XPS and humidity sensing behaviour of Sm3+ doped cobalt chromite (CoCr2O4). All samples are synthesized using solution combustion method with urea and glucose as fuels. The X-ray diffraction analysis confirms the single-phase formation with a spinel cubic structure. Field emission scanning electron microscopy micrographs revealed that the materials are porous and include soft agglomerations. Elemental analysis was performed using Energy-dispersive X-ray spectroscopy analysis, confirming the presence of Samarium (3+) in the Sm3+ doped CoCr2O4 samples. The oxidation state of each element was determined using X-ray photoelectron spectroscopy (XPS) for CoCr1.98Sm0.02O4 samples. The vibration bands identified by the Raman spectra confirm the formation of the spinel cubic structure. The electrical properties were measured by using an LCR meter, and it was observed that smaller crystallite size exhibits higher dielectric constant. All the electrical properties were found to increase with increasing samarium concentration. In humid conditions, this material's resistance to electricity and permittivity and permittivity changes with frequency, making it useful as a capacitive and resistive humidity sensor. The findings of this work pave the way for the use of metal-doped magnetic chromites in applications for humidity sensing. [ABSTRACT FROM AUTHOR]