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Second Harmonic Scattering (SHS) is a suitable technique to investigate the orientational correlations between molecules. This article explores the organization of different dye molecules adsorbed within the hydrophobic porosity of a hybrid organic–inorganic nanotube. Experimental polarization resolved SHS measurements highlight different orientational orders ranking from highly ordered and rigid organizations to disordered assemblies. Microscopic models of assemblies inside the pores are presented and discussed in the context of orientational correlation between the dye molecules. This work shows that the degree of order in the nanotube cavity follows the molecule's affinity within the porosity. [ABSTRACT FROM AUTHOR]

The prevention of drying-induced cracking is crucial in maintaining the mechanical integrity and functionality of colloidal deposits and coatings. Despite exploring various approaches, controlling drying-induced cracking remains a subject of great scientific interest and practical importance. By introducing chain-like particles composed of the same material and with comparable size into commonly used colloidal suspensions of spherical silica nanoparticles, we can significantly reduce the cracks formed in dried particle deposits and achieve a fivefold increase in the critical cracking thickness of colloidal silica coatings. The mechanism underlying the crack suppression is attributed to the increased porosity and pore sizes in dried particle deposits containing chain-like particle, which essentially leads to reduction in internal stresses developed during the drying process. Meanwhile, the nanoindentation measurements reveal that colloidal deposits with chain-like particles exhibit a smaller reduction in hardness compared to those reported using other cracking suppression approaches. This work demonstrates a promising technique for preparing colloidal coatings with enhanced crack resistance while maintaining desirable mechanical properties. [ABSTRACT FROM AUTHOR]

Most of the available data on diffusion in natural clayey rocks consider tracer diffusion in the absence of a salinity gradient despite the fact that such gradients are frequently found in natural and engineered subsurface environments. To assess the role of such gradients on the diffusion properties of clayey materials, through-diffusion experiments were carried out in the presence and absence of a salinity gradient using salt-diffusion and radioisotope tracer techniques. The experiments were carried out with vermiculite samples that contained equal proportions of interparticle and interlayer porosities so as to assess also the role played by the two types of porosities on the diffusion of water and ions. Data were interpreted using both a classical Fickian diffusion model and with a reactive transport code, CrunchClay that can handle multi-porosity diffusion processes in the presence of charged surfaces. By combining experimental and simulated data, we demonstrated that (i) the flux of water diffusing through vermiculite interlayer porosity was minor compared to that diffusing through the interparticle porosity, and (ii) a model considering at least three types of porous volumes (interlayer, interparticle diffuse layer, and bulk interparticle) was necessary to reproduce consistently the variations of neutral and charged species diffusion as a function of salinity gradient conditions.

We investigated the relationship between porosity and flexoelectricity for aluminum (Al)/polyvinylidene fluoride (PVDF) composites. Neat PVDF, composites of micron aluminum (μAl)/PVDF, and composites of nano aluminum (nAl)/PVDF were 3D printed, and the flexoelectric response was measured using a cantilever beam test setup. Voids (up to 72.4 mm3) were incorporated into the samples by decreasing the infill percent of the 3D printed material. We found that increasing the porosity via millimeter scale voids incorporated into the infill pattern decreased the average effective flexoelectric coefficient relative to the near full-density (100% infill) control samples. This contrasts with other studies that have shown increasing micron scale porosity increases the flexoelectric coefficient. In addition, we measured higher flexoelectric responses for nAl/PVDF than μAl/PVDF as well as for samples printed by the Hyrel 3D SR printer as opposed to the Ender 3 V2 printer. These results indicate that charge generation due to flexoelectricity can be altered by changing parameters such as porosity, particle size of inclusions, or manufacturing method. Smaller voids and fine particles can induce larger strain gradients than larger inhomogeneities, leading to increased flexoelectric coefficients. A competing effect is that more porosity leads to less materials, which can decrease the flexoelectric coefficient. [ABSTRACT FROM AUTHOR]

Reactive burn models for heterogeneous energetic materials (EMs) must account for chemistry as well as microstructure to predict shock-to-detonation transition (SDT). Upon shock loading, the collapse of individual voids leads to ignition of hotspots, which then grow and interact to consume the surrounding material. The sub-grid dynamics of shock-void interactions and hotspot development are transmitted to macro-scale SDT calculations in the form of a global reactive "burn model." This paper presents a physically evocative model, called meso-informed sub-grid source terms for energy localization (MISSEL), to close the macro-scale governing equations for calculating SDT. The model parameters are explicitly related to four measurable physical quantities: two depending on the microstructure (the porosity ϕ and average pore size D ¯ v o i d ), one depending on shock–microstructure interaction (the fraction of critical voids ξ c r ), and the other depending on the chemistry (the burn front velocity V h s ). These quantities are individually quantifiable using a small number of rather inexpensive meso-scale simulations. As constructed, the model overcomes the following problems that hinder the development of meso-informed burn models: (1) the opacity of more sophisticated surrogate/machine-learning approaches for bridging meso- and macro-scales, (2) the rather large number of high-resolution mesoscale simulations necessary to train machine-learning algorithms, and (3) the need for calibration of many free parameters that appear in phenomenological burn models. The model is tested against experimental data on James curves for a specific class of pressed 1,3,5,7-tetranitro-1,3,5,7-tetrazoctane materials. The simple, evocative, and fast-to-construct MISSEL model suggests a route to develop frameworks for physics-informed, simulation-derived meso-informed burn models. [ABSTRACT FROM AUTHOR]

Gas–liquid two-phase stratified flow exists in many industrial processes. Although the flow pattern is simple, the interfacial shear prediction of stratified flow is still the focus of the study. The calculation of the shear stress at the gas–liquid interface is closely related to the measurement of the void fraction and pressure drop of the stratified flow. In this study, a new method for the calculation of interfacial shear stress of gas–liquid two-phase stratified flow is proposed. Differential pressure measurement and planar laser-induced fluorescence technology are combined to obtain important parameters for stratified flow under low-speed flow conditions (Ql = 0.10–0.25 m3/h, Qg = 0.35–1.00 m3/h). The interfacial shear stress is successfully calculated using macroparameters. The uncertainty associated with the calculated parameters using the proposed method is 2.67%, and this study verifies the accuracy of the linear relationship. The method provides a new way to obtain the interfacial shear stress of gas–liquid stratified flow. [ABSTRACT FROM AUTHOR]

Utilizing molecular dynamics simulation, this study aims to explore the phase transformation behavior of porous nanocrystalline (NC) NiTi shape memory alloys (SMAs) when subjected to cyclic deformation. The influences of porosity and cyclic deformation on the phase transformation of NC NiTi SMAs are examined and discussed. The simulation results show that the increase in the porosity and number of cycles leads to a decrease in both the critical phase transformation stress and peak stress whereas an increase in the residual martensite, phase boundary, and interstitial atoms; the related results can be supported by previous experiments. After cyclic deformation, the reduction in the potential energy for the entire system during the tensile phase occurs at an earlier stage, indicating that the martensitic transformation occurs earlier as the number of cycles increases. Notably, the dissipated energy demonstrates a decrease with an increasing number of cycles, and the potential energy during the austenite elastic unloading stage undergoes a transition from a decreasing to an increasing trend due to the presence of residual martensite increasing with the number of cycles. [ABSTRACT FROM AUTHOR]

The behavior of energetic materials is significantly influenced by the spatial distributions of microstructure heterogeneities and voids. We pursue the concept of Functionally Graded Energetic Materials whose microstructure features (e.g., grain size, grain volume fraction, void size, and void volume fraction) change spatially such that they may allow the behavior of the materials to be tailored. We explore using gradients in the density of voids to alter the detonation behavior of a polymer-bonded explosive (PBX) echoing PBX9501 with HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) grains and Estane binder. Five cases, two graded void distributions from 1% to 10% and 10% to 1% by volume along the length of the sample, and three uniform distributions matching the lowest (1%), average (5.5%), and highest (10%) void densities are considered. An Arrhenius reaction burn model is used to account for the chemical kinetics of HMX. Different detonation behaviors are obtained from the same graded sample when impact loading is from 1% void end and from the 10% void end as well as from the uniform cases. The SDT (shock to detonation transition) behaviors are analyzed in terms of the run distance, the time duration and shock velocity changes over the SDT process. The computational results are presented in the context of available experimental data for PBX9501 with which agreement is obtained through a parametric study. Overall, it is shown that gradients in microstructures of PBX can lead to SDT behaviors different or not obtainable from microstructures without gradients, thereby offering a mechanism for designing and tailoring new materials. [ABSTRACT FROM AUTHOR]

In this study, analytical models for space charge limited current (SCLC) transport in a porous (or disordered) trap-limited dielectric cylindrical configuration are developed. The method used in this paper is first verified by reproducing the well-known analytical results for planar cases developed decades ago based on the traditional approach. By considering the porous solid as a fractional object characterized by a parameter α ≤ 1 , we formulate its fractional capacitance and determine the SCLC transport by using the transit time approach. At α = 1 , it will recover the well-known Mott–Gurney law and Mark–Helfrich law for trap-free and trap-limited cases, respectively. For cylindrical geometry, our findings show an analytical form that is not available from the traditional methods. We anticipate that the proposed analytical model will serve as a useful tool for characterizing the current–voltage measurements in SCLC transport in dielectric breakdown and organic electronics, where spatial porosity of the materials is inevitable. The introduced fractional parameter α extracted from such characterization can facilitate the quantitative determination of the relationship between spatial porosity and charge mobility. [ABSTRACT FROM AUTHOR]

Our study examines 'Finstagramming' as a resistance strategy from influencers trying to circumvent the prescriptive nature and restrictive algorithm of Instagram. Without ever leaving the platform, Finstagram acts as an emancipatory outlet that enables influencers to share more intimate, less-conforming and unpolished content without jeopardising the highly curated, monetizable person-brand of their main account. Through a dual-method qualitative approach of netnography and in-depth interviews, we unravel this paradox of embedded escapism, where influencers toggle between main and Finsta accounts in their pursuit of authenticity. Our findings reveal the porosity of these multiple digital personae and differentiated digital work taking place on the platform. We argue that Finstagram affords a momentary escape from the digital attention economy whilst remaining tethered to socially mediated authenticity markers. [ABSTRACT FROM AUTHOR]

The principle of the conventional ultrasound test states that the detectable voids cannot be smaller than the acoustic wavelength. However, by using effective medium approximation, the fraction of small voids can be estimated by the variation of the effective density. In this study, a non-contacting ultrasound-based porosity fraction mapping methodology is developed for estimated small voids in coal with long operating wavelength in air. This novel ultrasonic technique based on the mechanical properties of coal offers a rapid scan of the effective density mapping and distribution of void fraction over a large sample area, which overcame the limitation of small voids detection in the conventional ultrasound testing. [ABSTRACT FROM AUTHOR]

Renewable energy sources, such as hydrogen play a crucial role in developing sustainable technologies. Hydrogen is one of the best candidates for future energy transition. Today, hydrogen storage techniques have become an important and debated issue in many countries. This study represents the first attempt to prepare CuCr 2 O 4 nanoparticles using two different methods (sol-gel and green) and compare their performance as an electrocatalyst in electrochemical hydrogen storage. The tetragonal crystal structure, spherical shape, purity, and mesoporous features of the sample were studied using X-ray diffraction (XRD), Fourier transform infrared (FT-IR), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDS), and Brunauer-Emmett-Teller (BET) techniques. Additionally, the hydrogen storage performance of CuCr 2 O 4 nanoparticles was investigated using cyclic voltammetry (CV), and charge-discharge chronopotentiometry (CP) in a 3 M KOH alkaline medium. The result revealed that the specific capacitance values of CuCr 2 O 4 nanoparticles in sol-gel and green methods were obtained to be 2427 and 1503 Fg-1, respectively. The discharge capacities of CuCr 2 O 4 nanoparticles in sol-gel and green methods after 11 cycles were calculated to be 4304 and 3011 mAh/g, respectively. The superior hydrogen storage capability of CuCr 2 O 4 nanoparticles in the sol-gel method can be attributed to its high porosity. [Display omitted] • CuCr 2 O 4 nanoparticles were synthesized using the sol-gel and green methods. • Study of crystal structure, morphological, and electrochemical properties of the samples. • CuCr 2 O 4 showed excellent hydrogen storage capacity of 4304 and 3011mAh/g in the sol-gel and green methods, respectively. • A promising material for hydrogen storage applications. [ABSTRACT FROM AUTHOR]

Using a mixture of TiH 2 , Al, B 4 C, and graphite powders with a molar ratio of 3+2 m/1.2/m/2-m (where m ranges from 0 to 0.25, with increments of 0.05), porous Ti 3 AlC 2 -TiB 2 composite ceramics were successfully synthesized through activated reaction sintering. The effect of B 4 C content on the phase composition, volumetric expansion, microstructure, and pore structure parameters (including pore size, porosity, and permeability) was systematically studied. When the molar ratio of B 4 C was less than 0.1, the volumetric expansion rate, average pore size, and permeability increased with the addition of B 4 C, reaching maximum values of −5.46 %, 2.23 μm, and 92.4 m3 m−2·10 kPa−1 h−1, respectively. Conversely, when the B 4 C molar ratio exceeded 0.1, the parameters related to the pore structure of the porous Ti 3 AlC 2 -TiB 2 composite ceramics decreased, with minimum values of −10.40 %, 1.46 μm, and 68 m3 m−2·10 kPa−1 h−1, respectively. In addition, the pore formation mechanism of the porous Ti 3 AlC 2 -TiB 2 composite ceramics was systematically explored. The revolution tendency of pores is related to the decomposition of TiH 2 , Kirkendall partial diffusion, diffusion between B and C, and the transition process of the final phase Ti 3 AlC 2 -TiB 2. This research work could provide a reference for the preparation of the MAX phase composite porous materials. [ABSTRACT FROM AUTHOR]

Hierarchically porous biphasic calcium phosphate (BCP) ceramics with triply periodic minimal surface structure and porous framework have been fabricated by digital light processing (DLP) using dual-phase Pickering emulsion as the paste. The pristine hydroxyapatite and β-tricalcium phosphate particles were separately modified by dispersant firstly to obtain photosensitive Pickering emulsion with suitable rheological properties and stability for DLP printing. The porous structure has been well regulated by dispersant content, and ethylene glycol content. The resulting BCP ceramics exhibited a hierarchical pore structure consisting of interconnected micropores ranging from 1.13 μm to 8.98 μm and model-designed pores of nearly 500 μm, demonstrating excellent compressive strength of 4.83 MPa at a porosity of 60 %. In vitro biological experiments revealed that rat bone marrow mesenchymal stem cells exhibited good proliferation and adhesion ability on the BCP bio-scaffolds, thereby enhancing their application potential in bone regenerative medicine. [ABSTRACT FROM AUTHOR]

Microstructural evolution during the sintering of tetragonal ZrO 2 nanoparticles was investigated using stress-free sintering and sinter forging. The green body prepared via gel casting had a densely packed structure with a narrow pore size distribution. Special attention was paid to the evolution of pore structures in the initial and intermediate stages of sintering. Pore coarsening, which is considered an important issue in the nanoceramics densification, was not remarkable in sinter forging. The accelerated densification rate, coupled with the retention of finer pore size than that in stress-free sintering throughout densification, lowered the sintering temperature requirement. This temperature reduction effectively inhibited grain growth, allowing samples prepared via pressure-assisted sintering to maintain a nanometric structure. [ABSTRACT FROM AUTHOR]

Flexible crystalline solids exhibit unique properties in response to external stimuli like heat and light. However, challenges exist in developing crystalline solids that have similar degrees of flexibility as in solution. Herein, we report the preparation of the new flexible crystalline metal complex [Cd(CF3SO3)2(4‐spy)4] (4‐spy=4‐styrylpyridine), which contains photoreactive 4‐spy ligand. Unlike traditional solids, this metal complex displays solution state‐like [2+2] photocycloaddition reactivity. Specifically, UV irradiation of the crystalline material leads to formation of the same diverse array of dimers and cis isomer that are generated by photoreaction in the solution state. In addition, the photoresponsive flexibility of the solid leads to a photosalient effect and photo‐induced formation of pores. The origin of the solution state‐like photoreactivity of the solid is related to properties of the Cd(II) cation and fluorinated CF3SO3 anion, and the multi‐orientational arrangement of the 4‐spy ligands. [ABSTRACT FROM AUTHOR]

The B, N co-doped carbon matrix loaded with ultra-small Ru nanoparticles (Ru/BNC) is an excellent bifunctional catalyst capable of efficiently catalyzing ammonia borane hydrolysis and alkaline water electrolysis for hydrogen evolution. [Display omitted] Developing a straightforward and general strategy to regulate the surface microenvironment of a carbon matrix enriched with N/B motifs for efficient atomic utilization and electronic state of metal sites in bifunctional hydrogen production via ammonia-borane hydrolysis (ABH) and water electrolysis is a persistent challenge. Herein, we present a simple, green, and universal approach to fabricate B/N co-doped porous carbons using ammonia-borane (AB) as a triple functional agent, eliminating the need for hazardous and explosive functional agents and complicated procedures. The pyrolysis of AB induces the regulation of the surface microenvironment of the carbon matrix, leading to the formation of abundant surface functional groups, defects, and pore structures. This regulation enhances the efficiency of atom utilization and the electronic state of the active component, resulting in improved bifunctional hydrogen evolution. Among the catalysts, B/N co-doped vulcan carbon (Ru/BNC) with 2.1 wt% Ru loading demonstrates the highest performance in catalytic hydrogen production from ABH, achieving an ultrahigh turnover frequency of 1854 min−1 (depending on the dispersion of Ru). Furthermore, this catalyst shows remarkable electrochemical activity for hydrogen evolution in alkaline water electrolysis with a low overpotential of 31 mV at 10 mA cm−2. The present study provides a simple, green, and universal method to regulate the surface microenvironment of various carbons with B/N modulators, thereby adjusting the atomic utilization and electronic state of active metals for enhanced bifunctional hydrogen evolution. [ABSTRACT FROM AUTHOR]

The introduction of pores to improve the toughness of alumina ceramics is considered to be a feasible strategy by using the inhibitory effect of pores on crack propagation. However, the mechanical properties of alumina ceramics are often reduced due to the uncontrollable pore shape. In this work, the nano-scale C@Al 2 O 3 core-shell particles were fabricated and introduced into the alumina powder treated by dielectric barrier discharge plasma-assisted milling, and the alumina ceramics with closed pores of regular shape (approximate sphere) and small size (<1 μm) were prepared. Since the approximate spherical pore structure and small pore size eliminate the adverse effects of stress concentration, and the deflection and pinning effect of closed pores on cracks, the flexural strength and fracture toughness of the prepared samples were improved, increasing by 12.6 % and 18.8 % respectively. [ABSTRACT FROM AUTHOR]

Cement-based pervious concrete was prepared respectively with quartz powder, fine sand and silica fume as inorganic reinforcers. The influence of different inorganic reinforcers to the compressive strength, effective porosity and permeability coefficient of pervious concrete was investigated. The results show that the compressive strength of pervious concrete can be improved by adding certain amount of the inorganic reinforcing materials. In order to achieve the compressive strength of C25 and maintain good permeability, the content of quartz powder and fine sand should be 6% at least and 6%-8% of the total amount of coarse aggregate, and the content of silica fume should be 6%-10% of the total amount of cementitious material. Using the quadratic function equation, the permeability coefficient of pervious concrete can be obtained indirectly by measuring the effective porosity of pervious concrete. [ABSTRACT FROM AUTHOR]

Water flooding is an important way to improve recovery in low‐permeability sandstone oil reservoirs. How to decouple the water flooding process using dynamic and static information is a hot topic. In this paper, taking the Paleocene low‐permeability oil sandstone, BY area, eastern Nanxiang Basin as an example, the microscopic water flooding process in the low‐permeability sandstone matrix was systematically investigated, and the characteristics of water channeling under the conditions of fracture existence were analyzed using the dynamic and static monitoring data. The results show that the target layer mainly develops frequently thin stacked composite sand bodies. Under the combined influence of matrix and fracture seepage, the low‐permeability sandstone developed by water flooding shows that there is a single direction of efficiency. The direction of advantageous water advancement is 45° north–east, and the speed of water flooding advancement is 2.57 m/day. Microscopic water‐drive oil experiments show that bound water is mainly distributed in the original low‐permeability sandstone as a membrane in the pore wall and as short rods in the throat. Differences in pore structure and petrophysical properties affect the residual oil content and degree of oil recovery. For sandstones with good petrophysical properties, mild water flooding can improve crude oil recovery. The increase in oil production is mainly concentrated in the early stage of water flooding development, and the increase in oil recovery degree is not significant with the increase in injection multiples in the middle and late stages. However, for sandstones with relatively poor petrophysical properties, water flooding is more effective in the early and late stages than in the middle stages. Therefore, it is necessary to adjust the water flooding measures according to the differences in the petrophysical properties of the sand body. Local tectonics and natural fracture strikes are important factors affecting the direction of the expansion of water flooding fractures. Overall, the prevention of water channeling in low‐permeability sandstones has to take into account the complex coupling between water flooding fractures, natural fractures, and hydraulic fractures. [ABSTRACT FROM AUTHOR]

Highlights Hydrogen‐fueled vehicles, recognized for their environmental benefits as they emit only water vapor, represent a sustainable alternative to traditional cars. This paper investigates the relationship between the microstructure and mechanical properties of carbon fiber‐reinforced epoxy composites used to manufacture lightweight hydrogen storage pressure vessels through the filament winding process. This fabrication technique, while common, often results in variable fiber orientations and porosity content that affect the mechanical properties of the composite structures. Our study uses tubes made from carbon fiber reinforced epoxy resin with different angular fiber orientations (±15° and ±30°) and multilayer structures to analyze how these variations impact the mechanical properties and damage behavior of the composites. A series of tests, including physical–chemical characterizations, porosity measurements, and multiscale mechanical assessments such as tensile and loading‐unloading analysis have been conducted. The results demonstrate that porosity, measured in the range of 5%–7%, significantly impacts mechanical performance. Moreover, a 40% decrease in Young's modulus was observed between the ±15° and ±30° fiber orientations, and a 65% reduction was noted for the multilayer structure. Microscopically, the presence of porosity initiates cracks and leads to fiber/matrix decohesion and fiber breakage. Mesoscopically, these defects can merge to form transverse cracks and micro‐delaminations between layers, highlighting the complex behaviors of these composites under loading. This information is critical for improving the design and durability of hydrogen storage systems. Porosity, measured in the range of 5%–7%, significantly affects mechanical performance, reducing Young's modulus by up to 40% between ±15° and ±30° fiber orientations and by 65% in multilayer structures. Fiber/matrix decohesion and crack initiation due to porosity lead to the formation of transverse cracks and micro‐delaminations between layers, affecting the durability of the composite. Optimizing fiber orientation and reducing porosity are critical to improving the mechanical performance and long‐term durability of hydrogen storage vessels. [ABSTRACT FROM AUTHOR]

Cracks are extensively existing in rocks and play a significant role in the acoustic anisotropy of cracked rocks. Rocks in nature are affected by pore pressure, whereas the crack deformation with pore pressure and the impacts of the crack deformation on the anisotropic acoustic properties remain little known. Combining the theoretical model with the laboratory measurements of the anisotropic velocities of artificial sandstone samples with and without aligned penny‐shaped cracks, we invert for the crack parameters that characterize the crack deformation as a function of pore pressure and theoretically simulate the impacts of pore pressure–induced variation in the crack parameters on the anisotropic velocities. The results show that with increasing pore pressure, the inverted crack porosity increases exponentially, whereas the inverted crack aspect ratio decreases exponentially and the two crack parameters are linearly correlated. Moreover, model calculation demonstrates that the anisotropic velocities exhibit distinct reductions with the variation in the crack parameters caused by increasing pore pressure. In particular, the reduction in the velocity of the shear wave travelling parallel to the crack plane with polarization perpendicular to the crack plane is the most pronounced. We also demonstrate that the effects of the pore pressure–induced increasing crack porosity on the anisotropic velocities are more pronounced than the impacts of the decreasing crack aspect ratio. The findings not only reveal the variation of the crack geometry with pore pressure and the effects of the crack deformation on the anisotropic velocities of the cracked rocks but also can provide theoretical support for improving the characterization of the cracks through seismic survey. [ABSTRACT FROM AUTHOR]

High‐performance thermoplastic composites of polyketones [poly‐aryl‐ether‐ketone (PAEK), poly‐ether‐ether‐ketone (PEEK), poly‐ether‐ketone‐ketone (PEKK)] reinforced with continuous carbon fiber (CF) were consolidated using towpreg produced by multi‐scale aqueous dispersion coating technique. An intra‐matrix trend of composite strength and void fraction was studied to identify the composite with maximum strength free of voids for each polyketone matrix. The CF/PAEK composite with a flexural strength of ~2047 MPa and ILSS of ~99 MPa with a fiber volume fraction of ~67% had the maximum strength free of voids among CF/PAEK composite and all polyketone composites studied. The highest crystallinity (34.5%), and the highest amount of hydrogen bonding and bonds formed between CF, PI nanoparticle, and PAEK explained the origin of strength in CF/PAEK composite. The maximum strength among CF/PEEK and CF/PEKK composite free of voids had a flexural strength of ~1861 MPa, ~1981 MPa; ILSS of ~74 MPa, ~60 MPa; fiber volume fraction of ~61% and ~ 65%, respectively. The polyimide (PI) nanoparticles layer on CF formed the fiber matrix interface, supported hydrogen bonding in all polyketone composites, and formed bonds with CF and matrices of PAEK and PEEK establishing a synergistic effect. Highlights: Intra‐matrix trend of strength and voids in polyketone composites studied.Void‐free, high‐performance, high fiber volume fraction composites developed.CF/PAEK composite had maximum strength among polyketone composites studied.PI nanoparticles formed bonds with CF and matrices of PAEK and PEEK.CF/PAEK composite strength originates from crystallinity, H bond, and bonding. [ABSTRACT FROM AUTHOR]

The complex pore structure of carbonates can influence gas storage process to different extents, depending on stored gas type. Hence, investigating gas displacement and residual trapping in such formations is crucial. Here, several CO 2 and H 2 core flooding experiments were performed using three carbonate samples. The drainage process is followed by brine imbibition to test gas residual trapping. Additionally, nuclear magnetic resonance (NMR) T 2 spectra measurements were conducted at different stages. The results show that H 2 had less displacement efficiency in carbonates compared to CO 2. The pore structure has a noticeable impact on CO 2 displacement efficiency. However, H 2 displacement efficiency is less sensitive to rock properties. The NMR-T 2 measurements show that CO 2 partially saturated medium-sized pores and almost filled all macropores during drainage. After imbibition, large pores are slightly re-saturated with brine with varying degrees compared to their initial brine saturations. H 2 shows lower residual trapping efficiency compared to CO 2. • CO 2 and H 2 had different displacement and trapping efficiencies in carbonate rocks. • H 2 had less displacement efficiency in carbonate rocks compared to CO 2. • Rock permeability and pore structure highly affected CO 2 displacement efficiency. • Pore structure had a significant impact on the gas residual trapping process. • Hydrogen had lower residual trapping efficiency compared to CO 2. [ABSTRACT FROM AUTHOR]

The atomically precise mental nanoclusters have been widely explored in catalysis. However, the easy aggregation of clusters limits their application. The porous structure of metal-organic framework can prevent the aggregation and growth of clusters. In this work, a copper-phosphine complex: Cu 2 (dppm) 2 (PF 6) 2 (Cu 2) was synthesized by one-pot method and then reacted with hydrogen sulfide to obtain a tetranuclear copper cluster: Cu 4 (S)(dppm) 4 (PF 6) 2 (Cu 4). The two copper clusters were successfully introduced into Zeolitic imidazole frameworks-67 (ZIF-67) to form Cu 2 -ZIF-67 and Cu 4 -ZIF-67. It found that after the introduction of Cu cluster, the pore size of ZIF-67 was increased leading to more exposed Co2+ and more unsaturated coordination mental sites, which is beneficial for electrochemical oxygen evolution reaction (OER). The OER ability of pure ZIF-67 was enhanced after the introduction of Cu 2 and Cu 4 clusters, in which Cu 4 -ZIF-67 displayed the best electrochemical performance. At 10 mA cm−2, it requires an overpotential of 340 mV. The lower Tafel slope and smaller charge transfer resistance reflect its faster dynamic process. This work provides a new idea for the development of OER electrocatalysts. • Atomically precise Cu clusters have been successfully introduced into ZIF-67. • After the introduction of Cu clusters, the pore size of ZIF-67 has been broaden and the coordination environment of Co2+ have been changed. • More Co2+ ions were exposed and rich unsaturated coordination sites were formed after the introduction of Cu clusters. • The electrochemical OER ability of ZIF-67 has been greatly improved after the introduction of Cu clusters. [ABSTRACT FROM AUTHOR]

This study investigates the impact of porosity distribution on the hydrogen storage performance of metal hydride (MH) reactors through numerical simulations. Firstly, the effects of different porosities on heat and mass transfer characteristics during hydrogen adsorption and desorption processes were analyzed. The results indicate that with increasing porosity, the hydrogen storage and release rates improved, but the hydrogen storage density decreased. To enhance reactor performance while maintaining hydrogen storage density, the bed porosity distribution was optimized. The optimization results showed that the hydrogen storage and release times of the MH reactor were reduced by 57.15% and 29.70%, respectively, at the same hydrogen storage density. Moreover, the optimized structure exhibited excellent hydrogen storage and release performance under different operating conditions, demonstrating its potential advantages in practical applications. • MH bed porosity significantly affects heat and mass transfer performance. • Bed porosity distribution is optimized by Monte Carlo algorithm. • Hydrogen storage and release times are reduced by 57.15% and 29.7%. • Optimized structure shows superior performance under various conditions. [ABSTRACT FROM AUTHOR]

Here we show a novel approach to characterize the gas transfer behavior of silicon-oxide (SiO x) coatings and explain the underlying dynamics. For this, we investigate the coating on a nm-scale both by measurement and simulation. Positron annihilation spectroscopy (PAS) and quantum mechanical electronic structure-based molecular dynamics simulations are combined to characterize the porous landscape of SiO x coatings. This approach analyses the influence of micropores smaller than 2 nm in diameter on gas permeation which are difficult to study with conventional methods. We lay out the main pore diameter ranges and their associated porosity estimates. An influence of layer growth on pore size and porosity was found, with an increased energy input during layer deposition leading to smaller pore sizes and a reduced porosity. The molecular dynamics simulations quantify the self-diffusion of oxygen and water vapor through those PAS deducted micropore ranges for hydrophilic and hydrophobic systems. The theoretical pore size ranges are fitting to our PAS results and complete them by giving diffusion coefficients. This approach enables detailed analysis of pore morphology on mass transport through thin film coatings and characterization of their barrier or membrane performance. This is a crucial prerequisite for the development of an exhaustive model of pore dominated mass transports in PECVD coatings. [ABSTRACT FROM AUTHOR]

Ordered macroporous silica particles as a photomaterial transparent solid matrix were synthesized from sodium silicate (Na2SiO3) as a silica source and sodium lauryl sulfate (SLS, an anionic surfactant), as a template to form pores via the consecutive sol–gel spray drying. The investigation is carried out in two stages, (1) controlling the particle morphology to obtain a spherical shape and (2) controlling the pore structure. The concentrations of the SiO2 precursor, carrier gas flow rate, feeding rate, and drying temperature were varied to identify their effects on particle morphology. Spherical and donut-shaped particle morphologies are more prominent when these parameters are used. On the other hand, the addition of SLS to the SiO2 precursor resulted in controlled macroporous silica particles, depending on the SLS concentration. The deposition of ZnO quantum dots (QDs) on the silica surface stabilizes the optical properties of ZnO by increasing the intensity of photoluminescence (PL) emission and demonstrating excitation-wavelength-dependent photoluminescence. The ZnO/SiO2 composite particles demonstrated the highest PL intensity with the use of 1 CMC SLS addition and a ZnO concentration of 25% mol, which was almost 30,000 times greater than that of pure ZnO particles. Therefore, an even distribution of ZnO QDs on the silica surface, which is influenced by the silica morphology and its ZnO concentration ratio, can minimize ZnO QDs agglomeration, directly reducing its functional characteristics as a photomaterial. [ABSTRACT FROM AUTHOR]

The effect of strand (S‐) and final (F‐) electromagnetic stirring (EMS) on solidification structure characteristic of a φ690 mm continuously cast round bloom has been investigated industrially and theoretically. The newly designed S1‐EMS equipped just below the foot zone takes great effect on both equiaxed ratio and distribution alignment, as well as central porosity. Larger current S1‐EMS leads to higher equiaxed ratio, more symmetrical equiaxed zone, and smaller diameter of central porosity, and the effect is much more obvious than conventional S2‐EMS and F‐EMS. It is also noticed that there should be a saturation effect of S1‐EMS on the promotion of equiaxed dendrite nucleation. The S2‐EMS is beneficial for the expanding of equiaxed zone and improving of central porosity. When S1‐EMS is weak, strong S2‐EMS results in more asymmetrical equiaxed zone. However, when S‐EMS is strong, strong S2‐EMS results in more symmetrical distribution of equiaxed zone. The F‐EMS takes a little impact on the expanding of equiaxed zone in the large‐sized round bloom, and almost no effect on the alignment. The central porosity, however, is improved by F‐EMS with the help of decrease in temperature gradient and compensation of solidification contraction. [ABSTRACT FROM AUTHOR]

In this study, we reported a defect‐rich porous carbon (SAC) derived from sodium alginate (SA) via combined processes of high‐temperature carbonization at N2 atmosphere, NaCl hard template, and HCl etching for high‐performance absorbents. Besides the meso/macro‐porous structure characterization performed with usual morphological and structural analysis methods, sub‐nanolevel atomic microdefects of the derived SAC were investigated by positron annihilation lifetime spectroscopy (PALS) for the first time. All the samples displayed hierarchical pore structure, including numerous 3D‐interconnected macroporous (0.5‐2 µm), abundant mesopores (3‐5 nm), and rich intrinsic microdefects (mean size of 0.304 nm). The specific surface area and pore volume of the optimized SAC sample were 1191.3 m2·g−1 and 0.69 cm3·g−1, respectively. It was confirmed that the adsorption process of the derived SAC to the dye molecules mainly occurred through a chemical and monolayer adsorption mechanism. The SAC sample showed high efficiency in dye removal, with superior removal capacitance of 230.5 mg·g−1 for anionic dye of methyl orange (MO) and 1655.1 mg·g−1 for cationic dye of Rhodamine B (RhB) at pH = 7, respectively, which were about two times of that of commercial AC for the presence of more active sites of the derived SAC. This study also exhibited that the derived defect‐rich porous carbons from natural‐polymers of SA can be considered as an effective adsorbent to remove MO and RhB dyes from industrially polluted water at neutral pH conditions. [ABSTRACT FROM AUTHOR]

To explore the influence of surfactant concentration on the pore structure and permeability of coal samples during the chemical enhancement of coalbed methane production, different kinds and different concentrations of surfactants were added to the chemical solution, and the coal samples were soaked. Methods such as low-field nuclear magnetic resonance testing (NMR), fractal theory, permeability testing, surface tension testing, and contact angle testing were employed to analyze the variation patterns of coal sample pore structure, fractal characteristics, and permeability, and to explore the correlation between surface tension, contact angle, and the degree of pore structure development. The results show that the increase in total porosity of coal samples, the increase in the seepage pore porosity, the decrease in Dt, and the growth rate of permeability increase with the increase in surfactant concentration, and are negatively correlated with the surface tension of the solution and the contact angle of the coal-solution interface, while the decrease in Ds is not significantly correlated with surfactant concentration, surface tension, or contact angle. In terms of the erosion effect of a chemical solution on coal samples, the influence of contact angle is greater than that of surface tension, while surface tension has the greatest impact on the development of adsorption pores. By adding different surfactants, the surface tension of the chemical solution and the contact angle of the coal-solution interface can be controlled, further promoting the erosion of coal samples, which is of positive significance for the chemical enhancement of coalbed methane production. [ABSTRACT FROM AUTHOR]

A 2D cyanido-bridged architecture ZnII-[WV(CN)8]3− is smoothly pillared by N,N′-di-(4-pyridyl)-1,4,5,8-naphthalenetetracarboxydiimide (4DPNDI) into 3D hybrid porous coordination polymer (PCP) {Zn II3 (DMA)6[WV(CN)8]2(4DPNDI)·8DMA}. It shows significant uptake of H2O, MeOH or CHCl3 vapours with easy regeneration to the native form, and breathing-type CO2 adsorption contrasting non-porosity towards N2, providing a new example of a highly flexible porous material. [ABSTRACT FROM AUTHOR]

Selective separation of 137Cs is significant for the sustainable development of nuclear energy and environmental protection, due to its strong radioactivity and long half-life. However, selective capture of 137Cs+ from radioactive liquid waste is challenging due to strong coulomb interactions between the adsorbents and high-valency metal ions. Herein, we propose a strategy to resolve this issue and achieve specific Cs+ ion recognition and separation by modulating the stacking modes of layered perovskites. We demonstrate that among niobate-based perovskites, ALaNb2O7 (A = Cs, H, K, and Li), HLaNb2O7 shows an outstanding selectivity for Cs+ even in the presence of a large amount of competing Mn+ ions (Mn+ = K+, Ca2+, Mg2+, Sr2+, Eu3+, and Zr4+) owing to its suitable void fraction and space shape, brought by the stacking mode of layers. The Cs+ capture mechanism is directly elucidated at molecular level by single-crystal structural analyses and density functional theory calculations. This work not only provides key insights in the design and property optimization of perovskite-type materials for radiocesium separation, but also paves the way for the development of efficient inorganic materials for radionuclides remediation. Selective capture of radiocaesium is challenging due to strong coulomb interactions between adsorbents and high valent metal ions. Here, authors propose a strategy of modulating the stacking modes of layered perovskites to achieve specific Cs+ recognition and separation. [ABSTRACT FROM AUTHOR]

AbstractThis study investigates groove-based controlled shape morphing in potatoes and carrots during drying. Stamps were manufactured and used to create groove depths (2 mm and 4 mm) onto the surface of the samples, which were then dried at various temperatures (45 °C, 55 °C, and 65 °C). Bending transformation, drying profiles, shrinkage, porosity, and surface morphology were measured as indicators of shape morphing. Potatoes exhibited a positive correlation between morphing transformation with increasing temperatures, reaching maximum angles of 244° (2 mm) and 263° (4 mm). Similarly, carrots showed similar observations with maximum bending angles of 145.1° (2 mm) and 153° (4 mm). The morphing in these samples was observed within the moisture content range of 1–0.5 kg water per kg solids and was concomitant with a substantial shrinkage of 80–84% in both samples. Grooving significantly affects the morphing, creating high-stress points and increasing the moisture transfer rate during drying. This study lays foundational knowledge for the controlled shape morphing of foods using drying technology. [ABSTRACT FROM AUTHOR]

Pore structures provide extra freedoms for the design of porous media, leading to desirable properties, such as high catalytic rate, energy storage efficiency, and specific strength. This unfortunately makes the porous media susceptible to failure. Deep understanding of the failure mechanism in microstructures is a key to customizing high-performance crack-resistant porous media. However, solving the fracture problem of the porous materials is computationally intractable due to the highly complicated configurations of microstructures. To bridge the structural configurations and fracture responses of random porous media, a unique generative deep learning model is developed. A two-step strategy is proposed to deconstruct the fracture process, which sequentially corresponds to elastic deformation and crack propagation. The geometry of microstructure is translated into a scalar of elastic field as an intermediate variable, and then, the crack path is predicted. The neural network precisely characterizes the strong interactions among pore structures, the multiscale behaviors of fracture, and the discontinuous essence of crack propagation. Crack paths in random porous media are accurately predicted by simply inputting the images of targets, without inputting any additional input physical information. The prediction model enjoys an outstanding performance with a prediction accuracy of 90.25% and possesses a robust generalization capability. The accuracy of the present model is a record so far, and the prediction is accomplished within a second. This study opens an avenue to high-throughput evaluation of the fracture behaviors of heterogeneous materials with complex geometries. [ABSTRACT FROM AUTHOR]

Estimation of the porosity of a hydrate reservoir is essential for its exploration and development. However, the estimation accuracy was usually less certain in most previous studies that simply assumed that there is a linear relationship between the porosity and single‐elastic wave velocities or other rock physical parameters, thus affecting the evaluation of the reserves. In the three‐phase Biot‐type equations that are fundamental to model a hydrate‐bearing reservoir, porosity, alongside hydrate saturation, mineral constituent proportions and hydrate–grain contact factor, is non‐linearly responded by density, compressional and shear wave velocities. To improve porosity estimation, we propose to invert simultaneously four‐parameter (porosity, hydrate saturation, mineral constituent proportions and hydrate–grain contact factor) using an iteratively nonlinear interior‐point optimization algorithm to solve a nonlinear objective function that is a summation of the squared misfits between the well log and three‐phase Biot‐type equation–modelled density, compressional and shear wave velocities. A test in Mount Elbert gas hydrate research well was conducted for the case of a gas hydrate stratigraphic test well where elastic wave velocities, density, porosity and mineral composition analysis data are available. The four‐parameter inversion yielded a lower root mean square error for porosity (0.0245) across the entire well‐logging section compared to previous estimations from the linear relationship, post‐stacked and pre‐stacked seismic traces as well as the pore‐filling effective medium theory model applied to other well cases. Additionally, the other three parameters demonstrated good agreement with well logs. Inversion tests conducted at three additional hydrate sites also produced accurate results. Consequently, the new method surpasses previous approaches in porosity estimation accuracy. [ABSTRACT FROM AUTHOR]

Geological formations provide a promising environment for the long‐term and short‐term storage of gases, including carbon dioxide, hydrogen and hydrocarbons, controlled by the rock‐specific small‐scale pore structure. This study investigates the nanoscale structure and gas uptake in a highly porous silica aerogel (a synthetic proxy for natural rocks) using transmission electron microscopy, X‐ray diffraction, and small‐angle and ultra‐small‐angle neutron scattering with a tracer of deuterated methane (CD4) at pressures up to 1000 bar. The results show that the adsorption of CD4 in the porous silica matrix is scale dependent. The pore space of the silica aerogel is fully accessible to the invading gas, which quickly equilibrates with the external pressure and shows no condensation on the sub‐nanometre scale. In the 2.5–50 nm pore size region a classical two‐phase adsorption behaviour is observed. The structure of the aerogel returns to its original state after the CD4 pressure has been released. [ABSTRACT FROM AUTHOR]

The methane steam reforming (MSR) reaction is a significant process for hydrogen production, and developing catalysts with high activity and stability is crucial. In this work, the supported perovskite catalysts of Ni/LaBO3 and Ru‐Ni/LaBO3 (B = Al, Fe) were prepared by the sol–gel method using citric acid as a gelling agent for MSR to hydrogen production. The phase composition, pore structure, and surface morphology of the prepared catalysts were characterized by X‐ray diffractometer, Brunauer–Emett–Teller, scanning electron microscopy and energy dispersive spectroscopy, and X‐ray photoelectron spectroscopy. The reaction activity and stability of the prepared catalysts were tested in the fixed‐bed reactor with the temperature range of 500–800°C. The effect of Ru addition on the structure of perovskite and catalytic performance of MSR is explored. The results showed that 1wt%Ru–15wt%Ni/LaAlO3 catalyst exhibited the most excellent activity and stability during the reaction compared with the other three catalysts. The CH4 conversion, H2 selectivity, and H2 yield of the 1wt%Ru–15wt%Ni/LaAlO3 catalyst could reach 94.68%, 79.78%, and 48.65%, respectively, under the reaction temperature of 800°C and gas hourly space velocity of 36 000 mL/(gh), which were higher than those of a commercial catalyst. It was because that the relatively large surface area of perovskite support provides more active site and the addition of Ru enable Ni to have a smaller size and more dispersion. This study could provide a reference of perovskite catalysts for hydrogen production by MSR. [ABSTRACT FROM AUTHOR]

Great progress has been made in marine shale gas of Wufeng–Longmaxi formations in the Sichuan Basin. However, shale gas exploration in the complex structural belt around the Sichuan Basin still faces great challenges. In this study, shales of Wufeng–Longmaxi formations collected from the northern Guizhou were taken as the studied target, organic matter (OM) characteristics, mineral composition, pore structure, methane adsorption capacity and in situ desorption gas content were measured, and the controlling factors of shale gas content were further discussed. The results indicated that the sedimentary facies of Wufeng–Longmaxi formations in north Guizhou varies from shallow‐water shelf facies to deep‐water shelf facies from south to north, and organic‐rich shales are primarily distributed in Daozhen‐Xishui areas, with a maximum thickness of about 80–100 m. Organic‐rich shales are characterized by high total organic carbon (TOC) content, high thermal maturation and type I–II1 kerogens, which can be comparable with those in commercially produced shale gas field in Sichuan Basin. High‐quality shale gas reservoirs generally have a high content of brittle minerals, making them easier to be fractured. OM pores are the dominanted pore type in the studied shales, followed by intergranular pores associated with brittle minerals, dissolution pores within carbonate grains and microcracks, while clay mineral‐related pores are poorly developed. The Wufeng–Longmaxi Formation shales generally have strong methane adsorption capacities, but these vary greatly across different areas. Shale gas adsorption capacity is primarily controlled by TOC content and thermal maturation level. Similarly, total gas content, including desorption gas and lost gas, varies greatly in different areas, and it is obviously lower than that in Fuling and Luzhou shale gas field, due to the loss of shale gas and low‐pressure coefficient in the complex structural zone. It is worth explaining that shale gas is not always low in northern Guizhou, which is determined by burial depth and the distance of great fractures. Shale gas content is relatively high in LY1 well and DY1 well in Xishui‐Daozhen area, and it is extremely low in TY1 well and AY1 well in Tongzi‐Zheng'an area. Shale gas content in the same structural unit is primarily influenced by TOC content, OM pore development degree and water saturation. However, different structural units have different shale gas contents, due to the differences in preservation conditions. Shale reservoirs with good preservation conditions, that is, wide and gentle structure, far from a large fault and great burial depth, generally have high shale gas contents. [ABSTRACT FROM AUTHOR]

Flexible electronics which are easy to manufacture and integrate into everyday items require suitable memory technology that can function on flexible surfaces. Herein, the properties of Ge‐rich GeSbTe (GST) and Se‐substituted GeSbSeTe (GSST) phase‐change alloys are investigated for application as nonvolatile write‐once and rewritable memories in flexible electronics. These materials have a higher crystallization temperature than the archetypal composition of Ge2Sb2Te5 and hence better data retention properties. Moreover, their high crystallization temperature provides for a particularly straightforward implementation of a write‐once memory configuration. Material properties of Ge‐rich GST and GSST are measured as a function of temperature using four‐point probe electrical testing, Raman spectroscopy, and X‐ray diffraction. Following this, the switching of flexible memory devices is investigated through both simulation and experiment. More specifically, crossbar memory devices fabricated using Ge‐rich GST are experimentally fabricated and tested, while the operation of GSST pore cell structures suitable for flexible memory applications is demonstrated through simulation. [ABSTRACT FROM AUTHOR]

Significant evidence now supports the quality improvement seen in castings that employ naturally pressurized filling systems in their production. However, despite the documented evidence for improvement, these systems have not become ubiquitous. Gray iron, the industry's most prominent alloy, has been particularly slow to accept the shift in system design. The suggested tolerability of gray iron to turbulence, the market's price sensitivity, and the perceived economics of naturally pressurized systems are potential factors that have hindered adoption. However, if, through improved quality, the economic justification for these systems can be made in this adverse setting, there is a merit in their application to all alloys and processes. A sample gray iron part, currently being produced in a foundry environment with known porosity issues, was selected, to which a new system and several basin designs were applied. A mixed method analysis of casting simulations, production trials, and economic and environmental modeling was used to evaluate system performance. The results show a strong association between filling system design and sub-surface porosity. However, no association was found between basin design and porosity occurrence at lower porosity levels. Nevertheless, the economic and environmental modeling highlights that quality-orientated systems yield significant financial and environmental savings for the organization due to reduced scrap levels. These findings imply that quality-orientated system designs should be employed even when cost is the most critical measure. [ABSTRACT FROM AUTHOR]

Focusing on promoting the widespread application of crystal self-healing technology in marine concrete engineering and improving the durability of marine concrete, the research on the chloride ion transport behavior and corrosion resistance of concrete with crystal admixtures under the action of seawater is conducted. Ion chelator (CA) as crystalline admixture can obviously improve self-healing of cement-based materials. Results showed that CA improved pore structure of mortar, increased the compactness of matrix, and thus limited the chloride diffusion. After 3 months of erosion by NaCl + Na2SO4, NaCl + MgCl2 and NaCl + MgCl2 + Na2SO4 solutions, compared with control sample, the chloride diffusion coefficient of 100%OPC mortar with CA decreased by 49.3%, 47.4%, 56.5%, and 52.9%, respectively. CA-enhanced chloride binding ability of 100%OPC and 50%BFS mortar. Compared with control sample, the chloride binding efficiency of 100%OPC mortar with CA and 50%BFS mortar with CA increased by 26.1% and 35.5% after 3 months of NaCl solution corrosion, increased by 35.3% and 48.0% after 3 months of NaCl + Na2SO4 solution corrosion, and increased by 46.2% and 61.9% after 3 months of NaCl + MgCl2 solution corrosion, respectively. SEM analysis showed that CA could significantly improve internal microstructure of mortar under salts erosion. The correlation analysis of pore structure and chloride diffusion coefficient displayed that total porosity of mortar had better correlation with chloride diffusion coefficient than gel pore, transition pore, capillary pore and macropore after salt erosion. Therefore, CA mainly limited chloride diffusion into matrix by reducing total porosity of mortar under salt erosion. The research results of this paper can provide theoretical support and basis for the application of crystal self-healing technology in marine concrete. [ABSTRACT FROM AUTHOR]

Castor oil has been widely used in various fields due to its properties, leading to large attention for its extraction mechanism. To research the castor oil extraction mechanism during pressing, a self‐developed uniaxial compression device combined with an in situ observation is established. The effects of pressure, loading speed, and creep time are investigated, and a finite element model coupling with multi‐physics is established for castor oil pressing extraction, verified by the seed cake experimental compression strain matching with numerical simulation under the same condition. Simulation results indicated that the pressing oil extraction process can be divided into two stages, Darcy's speed shows the first sharp decreasing stage and the second gradual increasing stage during porosity and pressure interaction. In the first stage, porosity is dominant on Darcy's speed. With porosity decreasing, the pressure effect on Darcy's speed exceeds porosity in the second stage. With seed thickness increasing, Darcy's speed first increases and then decreases. With loading speed increasing, Darcy's speed increases. Darcy's speed decreases constantly with creep time increasing. This study can provide basic theoretical and practical guidance for oil extraction. [ABSTRACT FROM AUTHOR]

This article offers a new strategy for cognizing musical indeterminacy based on Richard Sennett's "five open forms for the city," an intrinsically spatial way of thinking about what is "open" and how it is open. Sennett's five forms ("synchronicity," "punctuatedness," "porosity," "incompleteness," and "multiplicity") are explored individually as they impact our understanding of openness and/in music, illuminated by examples from contemporary experimental music. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) exhibit large surface areas and low thermal conductivity, making them promising for thermoelectric generation. However, their limited electrical conductivity poses a significant hurdle to be practically useful. Traditionally, enhancing the electrical conductivity of MOFs typically comes at the cost of reducing surface area, thereby increasing thermal conductivity. This study introduces an approach to simultaneously boost the electrical conductivity and porosity of a MOF‐based material while maintaining remarkably low thermal conductivity. The electrically conductive poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS) is deployed to nucleate the growth of Cu3(BTC)2 (or simply CuBTC, where BTC = benzene‐1,3,5‐tricarboxylic acid), resulting in the synthesis of composites labeled CPP‐y (where y denotes wt% PEDOT:PSS). Predictably, the CPP‐y composites are more electrically conductive than pure CuBTC, achieving an electrical conductivity exceeding 1.40 S cm−1 at room temperature. Furthermore, the CPP‐y composites exhibit consistently high Brunauer–Emmett–Teller (BET) surface areas of ≈1600 m2 g−1, comparable to pristine CuBTC, while maintaining thermal conductivities below 0.04 W m−1 K−1 at room temperature. With a high Seebeck coefficient in the range 180–373 µV K−1, CPP‐15 and CPP‐23 demonstrate a figure‐of‐merit (zT) of 0.25 and 0.11, respectively, at 285 K, marking a substantial achievement for MOF‐based materials. [ABSTRACT FROM AUTHOR]

Hard carbon (HC) materials with rich closed pore structures and nano‐scaled soft carbon coating layer have emerged as promising anode in sodium‐ion batteries (SIBs). However, it still remains a tremendous challenge to precisely regulate closed pore structures and soft carbon coating thicknesses for achieving excellent electrochemical performance in SIBs at low‐voltage platforms. Herein, PCHC‐10 with abundant and suitable‐sized closed pore size (0.45 nm) and nano‐scaled soft carbon coating layer has been accurately designed by chemical crosslink reaction between the pre‐oxidized phenolic resin and a small addition of pitch to form ester‐based bond. As anode, PCHC‐10 delivered large reversible capacity of 359.8 mAh g−1 within 0.001–2.5 V, and high capacity of 242.8 mAh g−1 in low voltage platforms (≤0.15 V). Besides, PCHC‐10 anode exhibits 91.4% capacity retention for 100 cycles, and Na3V2(PO4)3//PCHC‐10 full cell has superior rate performance and high energy density of 231.2 Wh kg−1. Furthermore, the detailed electrochemical storage behaviors and theoretical calculations revealed that the HC owning closed pore‐size of 0.45 nm has the strongest Na+ storage abilities in low‐voltage platforms. This work presents a novel insight for constructing HC with suitable‐sized closed pore structures and soft coating layer to boost Na+ storage capability in low‐voltage platforms. [ABSTRACT FROM AUTHOR]