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Mg-Zn-based alloys have been widely used in computer, communication, and consumer (3C) products due to excellent thermal conductivity. However, it is still a challenge to balance their mechanical performance and thermal conductivity. Here, we investigate microstructure, mechanical performance, thermal conductivity and metal fluidity of Mg-5Zn (wt.%) alloy after Cu alloying by experimental and simulation methods. First, Mg-5Zn alloy consist of α-Mg matrix and interdendritic MgZn phases. As the Cu content increases, however, MgZn phases disappear but intragranular Mg2Cu and interdendritic MgZnCu phases appear in Mg-5Zn-Cu alloys. Besides, the grain size of α-Mg phase is refined and the volume fraction of MgZnCu phase increases as the Cu content increases. Second, Cu addition is found to improve thermal conductivity of Mg-5Zn alloy remarkably. Especially, Mg-5Zn-4Cu alloy exhibits the best thermal conductivity of 124 W/(m·K), which is mainly due to the significant reduction in both solid solubility of Zn in the α-Mg matrix and lattice distortion of α-Mg matrix. Moreover, a stable crystal structure of MgZnCu phase also contributes to an increased thermal conductivity based on first principles and molecular dynamics simulations. Third, Cu addition simultaneously enhances strength and ductility of Mg-5Zn alloy. Tensile yield strength and elongation of Mg-5Zn-6Cu alloy reach 117 MPa and 18.0 %, respectively, which is a combined result of refinement, solution, second phase, and dislocation strengthening. Finally, combined with a phase field simulation, we found that Cu addition enhances metal fluidity of Mg-5Zn alloy. On the one hand, Cu alloying not only delays dendrite growth but also prolongs solidification time. On the other hand, MgZnCu phase stabilizes the dendrite growth of the α-Mg phases by reducing energy consumption during solidification of liquid metal. This work demonstrates that Cu alloying is an ideal strategy for synergistically improving the thermal conductivity, mechanical performance and metal fluidity of Mg-based alloys.

Biochar is a carbon-rich product obtained by pyrolyzing biomass under oxygen-limited conditions and has a wide range of potential for environmental applications. In particular, dissolved organic matter (DOM) released from biochar has an important impact on the fate of pollutants. The study aimed to systematically assess how varying pyrolysis temperatures and biomass feedstocks influence the characteristics of biochar-derived DOM. DOM samples were comprehensively characterized utilizing UV-vis spectroscopy and excitation–emission matrix (EEM) fluorescence spectroscopy, coupled with parallel factor (PARAFAC) analysis. The study discovered that pyrolysis temperature significantly affects DOM characteristics more than feedstock type. An increase in pyrolysis temperature correlated with a notable decrease in dissolved organic carbon content, aromaticity, and fluorescence intensity, alongside a marked increase in pH and hydrophilicity. PARAFAC analysis identified three distinct DOM components: two humic-like substances (C1 and C2) and one protein-like substance (C3). The proportion of protein-like substances increased with higher pyrolysis temperatures, while the humic-like substances’ proportion declined. The compositional shifts in DOM with pyrolysis temperature may significantly influence its environmental behavior and functionality. Further research is necessary to explore the long-term environmental impact and potential applications of biochar-derived DOM.

Abstract Biological ion channels exhibit high selectivity and permeability of ions because of their asymmetrical pore structures and surface chemistries. Here, we demonstrate a biomimetic nanofluidic channel (BNC) with an asymmetrical structure and glycyl-L-proline (GLP) -functionalization for ultrafast, selective, and unidirectional Dy3+ extraction over other lanthanide (Ln3+) ions with very similar electronic configurations. The selective extraction mainly depends on the amplified chemical affinity differences between the Ln3+ ions and GLPs in nanoconfinement. In particular, the conductivities of Ln3+ ions across the BNC even reach up to two orders of magnitude higher than in a bulk solution, and a high Dy3+/Nd3+ selectivity of approximately 60 could be achieved. The designed BNC can effectively extract Dy3+ ions with ultralow concentrations and thereby purify Nd3+ ions to an ultimate content of 99.8 wt.%, which contribute to the recycling of rare earth resources and environmental protection. Theoretical simulations reveal that the BNC preferentially binds to Dy3+ ion due to its highest affinity among Ln3+ ions in nanoconfinement, which attributes to the coupling of ion radius and coordination matching. These findings suggest that BNC-based ion selectivity system provides alternative routes to achieving highly efficient lanthanide separation.

The rapid solidification speed and significant temperature gradient observed in the wire and arc additive manufacturing (WAAM) process result in a deviation of the solid-liquid interface from the equilibrium state assumed by the conventional directional solidification phase field (PF) model. This, in turn, limits the ability of the traditional directional solidification PF model to accurately depict the microstructure evolution in additive manufacturing, where non-equilibrium effects dominate. In this work, we employed a 3D finite element (FE) model to simulate the temperature distribution during the wire and arc additive manufacturing (WAAM) process. Additionally, a modified PF model that applies to additive manufacturing is also used to simulate the dendrite morphology and solute segregation behavior in the WAAM process at different scanning speeds. Experimental validation of the simulation results was also conducted. We observed a significant reduction in dendrite growth velocity and solute segregation with increasing scanning speed, attributable to the combined effects of the temperature gradient G(t) and solidification speed Vp. Furthermore, higher scanning speeds were found to increase the primary dendrite arm spacing (PDAS) and average dendrite width. Importantly, our results demonstrated a quantitative agreement between the simulation results using the modified directional solidification PF model and the experimental observations. This approach provides a foundation for selecting and predicting processing parameters and microstructural characteristics under additive manufacturing conditions, facilitating a comprehensive analysis of dendrite growth and solute segregation at different scanning speeds in the WAAM process.

The anisotropy interfacial energy changes the growth tendency of dendrites in different directions during solidification, when the growth tendency in a specific direction appears or disappears, the transition of dendrite orientation will happen. In this study, three-dimensional simulations of anisotropic α‐Mg dendrite were conducted by changing the anisotropic interface energy in the phase field model. The variation in the preferred growth direction of equiaxed dendrite in α‐Mg was analyzed by controlling the anisotropic function of the interfaces. The changes in the growth direction of dendrites on different dendrite planes and the distribution of solute were investigated. The dendrites of α‐Mg equiaxed crystals mainly grow in ⟨112‾0⟩ and ⟨112‾3⟩ directions, and the transition of dendrite orientation depends on ⟨112‾0⟩ direction. When ⟨112‾0⟩ direction branching disappears, α‐Mg dendrite is transformed from 18 branches to 12 branches. The solute distribution at the front of the dendrite boundary changes significantly with the growth trend. Differences in the degree of solute distribution affect the solid-liquid interface and change the microstructure of the material.

In this article, a mid-infrared all-fiber light-induced thermoelastic spectroscopy (LITES) sensor based on a hollow-core anti-resonant fiber (HC-ARF) was reported for the first time. The HC-ARF was applied as a light transmission medium and gas chamber. The constructed all-fiber structure has merits of low loss, easy optical alignment, good system stability, reduced sensor size and cost. The mid-infrared transmission structure can be utilized to target the strongest gas absorption lines. The reversely-tapered SM1950 fiber and the HC-ARF were spatially butt-coupled with a V-shaped groove between the two fibers to facilitate gas entry. Carbon monoxide (CO) with an absorption line at 4291.50 cm−1 (2.33 µm) was chosen as the target gas to verify the sensing performance. The experimental results showed that the all-fiber LITES sensor based on HC-ARF had an excellent linear response to CO concentration. Allan deviation analysis indicated that the system had excellent long-term stability. A minimum detection limit (MDL) of 3.85 ppm can be obtained when the average time was 100 s

Although A356 aluminum alloy has poor ductility and strength, the refinement of the initial α-Al phase has shown promise in improving these properties. The impact of grain refinement mechanisms on the organization and morphology of A356 aluminum alloys has not been thoroughly investigated. In this paper, we constructed a phase field lattice-Boltzmann model to explore the influence of the refinement mechanism on the growth of α-Al dendrites during the non-isothermal solidification process of A356 aluminum alloy. The results demonstrated that the approach of alloying by adding elements, introducing forced convection, and increasing the degree of subcooling has proven to be effective in refining the dendrites of A356 aluminum alloy. The presence of Fe element further promotes the thinning of α-Al dendrites, and this effect is also found after melting ultrasonic treatment at a lower initial casting temperature. These findings are expected to provide theoretical support for effectively improving the hardness, ductility, and overall performance of Al-based alloys.

The design of gating systems for large and complex thin-wall castings requires the application of empirical equations and a substantial number of iterative experiments. In this study, a novel machine learning-based design strategy is proposed for the gating system of large and complex thin-walled castings. The gating system of castings was estimated using a multi-input multi-output neural network model, which incorporated visual, textual, and numerical multimodal features. The R2 value of the model accuracy reached 0.981, and the predicted parameters for the gating system were a slot runner width of 27 mm, a slot runner length of 48 mm, a riser runner diameter of 60 mm, and the number of riser runners of 8. The EasyCast and Procast simulation software were utilized for comparison and verification, resulting in a smooth filling and the achievement of sequential solidification. Finally, the mechanism of casting defects is discussed using the solidification phase-field model of EasyPhase system, elucidating how the alloy system can serve as a distinguishing feature in machine learning models that impact gating system parameters. This strategy is anticipated to enhance the efficiency of low pressure die casting process design, thereby serving as a valuable reference for intelligent process design in low pressure die casting.

Abstract Shellfish with rigid shells prevent damage to their delicate internal cores, and their soft bonding muscles drive the opening and closing of the shells. This synergism of rigid and soft materials provides shellfish with unique environmental adaptation. Inspired by the structural characteristics of mussels, a riveting layer was introduced into hydrogel-plastic hybrids for bonding hydrogel networks and plastic substrates. The bonding strength of the hydrogel on the polypropylene (PP) substrate was approximately 1.52 MPa, and the interface toughness reached 1450 J m−2. Furthermore, the integration of plastics and microscale hydrogels, as well as abscised or prefabricated hydrogels, could also be fabricated through the same process. By using this strategy, a hydrogel-plastic hybrid-based device with temperature responsiveness and scratch resistance was fabricated and could mimic the basic activities of mussels. This work improves the functional materials used in programmable engineering systems and could facilitate the construction of intelligent robots.

Thermal and solute diffusion plays an important role in α-Mg dendrite growth, the diffusion mechanism of which is still unclear. Here, thermal and solute diffusion in α-Mg dendrite growth of Mg-5wt.%Zn alloy under non-isothermal solidification were studied using the phase-field method. Results show that solidification latent heat will be concentrated at the dendrite intersection, which makes thermal field distribution non-uniform, and it is similar to the profile formed by connecting primary dendrite tips. The increase in temperature will shorten primary dendrite arms, reduce side-branching development, increase dendrite tip temperature, and decrease dendrite tip concentration stability. Moreover, solidification latent heat will first diffuse to undercooled melt, then diffuse to other areas, finally, system temperature tends to be unified. The variation range of concentration difference is very small in the solidification process, and solute field distribution is uniform all the time. The local high-concentration areas will be formed after the superposition of the solute enrichment layer, and solute atoms will first diffuse to undercooled melt through the solid-liquid interface, and then concentrate between side-branching and dendrites.

The convenient serpentine channel pouring (SCP) process is advantageous in broad industrial application. The key technique is the fast and stable production of semi-solid metal (SSM) slurry with non-dendritic microstructure. It is critical to take the whole technological process into consideration so as to achieve the optimal performance of SSM slurry rapidly and steadily. The present study makes an attempt to analyze and evaluate SCP process by comprehensive considering of the microstructure, mechanical property and yields. The established SCP process prediction models adequately approximated the actual values. The dimensional response surface accurately evaluated the interaction effects between process parameters on the characters of SSM slurry. Two kinds of numerical multiple-response optimization criteria were applied to achieve high-quality SSM slurry. The microstructure analysis and phase-field modeling clearly revealed the grain growth and microstructure evolution mechanism for SCP process. The comprehensive assessment concept and multiple-response optimization method in this work may bring positive and directive significance for the mass-scale production and application of SCP process.

BackgroundPelvic floor muscle strength is well-known to be associated with female sexual function. However, there were a few studies that reported on the relationship between pelvic floor muscle strength and female sexual function in pregnant women, and the presented results were inconsistent. Nulliparae represent a specific cohort with simplicity to exclude confounding factors that are caused by parity. The present study aimed to explore the association of pelvic floor muscle strength and sexual function based on the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ-12) of nulliparae during pregnancy.MethodsThis is the second analysis of the baseline data from a randomized controlled trial (RCT), which aimed to study the protective efficacy of pelvic floor muscle training on stress urinary incontinence at 6th week postpartum (registration number: ChiCTR2000029618). Nulliparae aged 20–40 years with singleton pregnancy before 16 weeks of gestation were enrolled in this study, and data, including participants' demographic information, the Modified Oxford Scale (MOS), and PISQ-12, were collected. Eligible nulliparae were divided into two groups: Group MOS > 3 and Group MOS ≤ 3. Demographic information of the two groups was compared. Sexual function based on the PISQ-12 scores of the two groups was compared. A comparison of the PISQ-12 scores between the two groups was calculated by the Mann–Whitney U-test using SPSS version 23.0.ResultsA total of 735 eligible nulliparae were enrolled in this study. Along with MOS grading up, PISQ-12 scores tended to get lower. Of the 735 nulliparae, there were 378 and 357 participants included in Group MOS > 3 and Group MOS ≤ 3, respectively. The PISQ-12 scores of Group MOS > 3 were significantly lower than those of Group MOS ≤ 3 (11 vs. 12, p < 0.001). The scores of the frequency of feeling sexual desire, orgasm achievement, sexual excitement, sexual activity satisfaction, sexual intercourse pain, fear of urinary incontinence, and negative emotion reactions with the sexual intercourse of Group MOS > 3 were lower than those of Group MOS ≤ 3 (p < 0.05).ConclusionPelvic floor muscle strength was positively associated with sexual function based on the questionnaire of young nulliparae during their first trimester. Up to half of the nulliparae during the first trimester were suffering from weak pelvic floor muscle strength and nearly a quarter of the nulliparae were facing this weakness combined with sexual dysfunction.Trial registrationThis study has been registered at http://www.chictr.org.cn (registration number: ChiCTR2000029618).

Membrane-based reverse electrodialysis is a promising technology for harvesting the osmotic energy to solve the increasingly severe energy problems. However, the osmotic power generation generally suffers from low power output for the poor performance of the ion-exchange membranes. Recently, bioinspired nanochannel membranes are emerging as an appealing materials platform for high-performance osmotic energy conversion owing to their tailorable physiochemical properties. In this review, we discuss tailored ion transmembrane transport and highlight the tunable synthesis of various polymeric materials with nanochannels for osmotic energy conversion, involving homopolymer membrane, blend membrane and Janus membrane. We then present a discussion of the structure−property relationships of polymeric nanochannel membrane based on ion transport dynamics, ultimately targeting properties such as enhanced ionic conductivities, ion selectivity, ion rectification, and desirable mechanical strength. Finally, we give an outlook to future research directions and applications. Advances in bioinspired nanochannel membranes based on polymeric materials will usher opportunities toward osmotic energy conversion, potentially transforming the power output from concept to applications.

Metal–phenolic networks (MPNs) are a new type of nanomaterial self-assembled by metal ions and polyphenols that have been developed rapidly in recent decades. They have been widely investigated, in the biomedical field, for their environmental friendliness, high quality, good bio-adhesiveness, and bio-compatibility, playing a crucial role in tumor treatment. As the most common subclass of the MPNs family, Fe-based MPNs are most frequently used in chemodynamic therapy (CDT) and phototherapy (PTT), where they are often used as nanocoatings to encapsulate drugs, as well as good Fenton reagents and photosensitizers to improve tumor therapeutic efficiency substantially. In this review, strategies for preparing various types of Fe-based MPNs are first summarized. We highlight the advantages of Fe-based MPNs under the different species of polyphenol ligands for their application in tumor treatments. Finally, some current problems and challenges of Fe-based MPNs, along with a future perspective on biomedical applications, are discussed.

BackgroundHepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide, with unclear pathogenesis. Sphingomyelin phodiesterase acid-like 3A (SMPDL3A) affects cell differentiation and participates in immune regulation. However, its molecular biological function in HCC has not yet been elucidated.MethodsData from 180 HCC patients were analyzed the relationship between the expression of SMPDL3A in liver cancer tissues and the prognosis of liver cancer patients. Crispr-Cas9 dual vector lentivirus was used to knock out SMPDL3A in HCC cell lines. The effects of SMPDL3A on cell viability were determined by CCK8 assay, clone formation experiment, cell cycle assay, cell scratch, TUNEL experiment and flow cytometry. Xenograft tumor assays in BALB/c nude mice confirmed that SMPDL3A promoted tumor growth and in vivo. Preliminary exploration of SMPDL3A interacting protein by mass spectrometry analysis and co-immunoprecipitation.ResultsThis study showed that the expression of SMPDL3A in HCC tissue differed from that in tumor-adjacent tissues. Moreover, the overall survival rate and tumor-free survival rate of patients with high-SMPDL3A expression were significantly lower than those with low-SMPDL3A expression. SMPDL3A expression was closely related to the level of protein induced by PIVKA-II, liver cirrhosis, tumor diameter, microvascular invasion, and Barcelona clinic liver cancer staging. Thus, SMPDL3A is an independent risk factor that affects the tumor-free survival rate and overall survival rate of HCC patients. In vitro study using Crispr-Cas9 genome editing technology revealed the knockout effect of SMPDL3A on cell proliferation, apoptosis, and migration. Cell counting kit-8 assay and clone formation experiment showed that sgSMPDL3A inhibited tumor cell proliferation and migration. Flow cytometry and TUNEL assay showed that sgSMPDL3A promoted apoptosis in tumors. Moreover, sgSMPDL3A inhibited tumor growth during subcutaneous tumor formation in nude mice. Immunohistochemistry of Ki67 and PNCA also indicated that sgSMPDL3A inhibited subcutaneous tumor proliferation in tumor-bearing nude mice. Further experiments showed that SMPDL3A interacts with the enhancer of rudimentary homolog (ERH).ConclusionsHigh-SMPDL3A expression was related to poor prognosis of patients with HCC. Knockout of SMPDL3A inhibited the proliferation and migration and accelerated the migration of HCC cells. SMPDL3A interacted with ERH to affect the tumorigenesis and progression of HCC.

Bloch electrons in multiorbital systems carry nontrivial quantum geometric information characteristic of their orbital composition as a function of their wave vector. When such electrons form Cooper pairs, the resultant superconducting state naturally inherits aspects of the quantum geometry. In this paper, we study how this geometric character is revealed in the intrinsic optical response of the superconducting state. In particular, due to the superconducting gap opening, interband optical transitions involving states around the Fermi level are forbidden. This generally leads to an anomalous suppression of the optical conductivity at frequencies matching the band separation—which could be significantly higher than the superconducting gap energy. We discuss how the predicted anomaly may have already emerged in two earlier measurements on an iron-based superconductor. When interband Cooper pairing is present, intraband optical transitions may be allowed and finite conductivity emerges at low frequencies right above the gap edge. These conductivities depend crucially on the off-diagonal elements of the velocity matrix in the band representation, i.e., the interband velocity—which is related to the non-Abelian Berry connection of the Bloch states.

Based on long-term lidar (light detection and ranging) observations at Yanqing (40.5°N, 116°E) and Pingquan (41°N, 118.7°E), cloud events occurred in the vicinity of the stratopause above Beijing were reported for the first time. These events occurred with tenuous and sparse layers within the altitude range of 33–65 km, and the maximum VBSC value ranged from 1×10−10m−1sr−1 to 5.5×10−9m−1sr−1. Considering temperature and water vapor measurements from SABER/TIMED, the occurrence mechanism of these lidar-observed cloud events was examined. It was found that some cloud layers resulted from the nucleation of water vapor due to the local meteorological changes in the middle atmosphere, while other lidar-observed clouds could comprise floating clusters of cosmic dust, hydrate droplets, volcanic ash, space traffic exhaust, etc. These cloud events are rare cloud-like phenomena in the middle atmosphere observed by lidars at midlatitudes in China; they differ from NLCs and PSCs in terms of altitude distribution and seasonal variation, and the relevant microphysics processes behind their occurrence are likely meaningful to meteorology at midlatitudes.

Background The number of patients diagnosed with early stage disease (T1a or T1b) has been increasing. This study was conducted to investigate the effect of esophagectomy (ES), endoscopic therapy (ET), and radiotherapy (RT) on long‐term survival in elderly patients with cT1N0M0 esophageal cancer. Methods We searched the Surveillance, Epidemiology, and End Results (SEER) database to identify the records of elderly patients (≥ 75 years) with cT1N0M0 esophageal cancer between 2004 and 2014. Patient demographics and esophageal cancer parameters were compared among ES, ET, and RT groups. The Kaplan–Meier method and Cox proportional hazard modeling were used to compare long‐term survival. Results Data from 954 esophageal cancer patients (ES: n = 196; ET: n = 224; RT: n = 534) were identified. Multivariate Cox regression analysis showed that five‐year survival in the ET and ES groups was significantly higher than in the RT group. After propensity score matching, we found no difference in five‐year survival between ES and ET. Conclusion Using SEER data, we identified a significant survival advantage with the use of ES and ET compared to RT in patients with cT1N0M0 esophageal cancer aged > 75 years, while the long‐term survival of patients after ET and ES was not significantly different.

Ti-Al alloys have excellent high-temperature performance and are often used in the manufacture of high-pressure compressors and low-pressure turbine blades for military aircraft engines. However, solute segregation is easy to occur in the solidification process of Ti-Al alloys, which will affect their properties. In this study, we used the quantitative phase-field model developed by Karma to study the equiaxed dendrite growth of Ti-4.5% Al alloy. The effects of supersaturation, undercooling and thermal disturbance on the dendrite morphology and solute segregation were studied. The results showed that the increase of supersaturation and undercooling will promote the growth of secondary dendrite arms and aggravate the solute segregation. When the undercooling is large, the solute in the root of the primary dendrite arms is seriously enriched, and when the supersaturation is large, the time for the dendrite tips to reach a steady-state will be shortened. The thermal disturbance mainly affects the morphology and distribution of the secondary dendrite arms but has almost no effect on the steady-state of the primary dendrite tips. This is helpful to understand the cause of solute segregation in Ti-Al alloy theoretically.

Fiber-reinforced polymer (FRP) jacketing/wrapping has become an attractive strengthening technique for concrete columns. Wrapping an existing concrete column with continuous FRP jackets with the fiber in the jacket being oriented in the hoop direction is referred to as FRP full wrapping strengthening technique. In practice, however, strengthening concrete columns with vertically discontinuous FRP strips is also favored and this technique is referred to as FRP partial wrapping strengthening technique. Existing research has demonstrated that FRP partial wrapping strengthening technique is a promising and economical alternative to the FRP full wrapping strengthening technique. Although extensive experimental investigations have hitherto been conducted on partially FRP-confined concrete columns, the confinement mechanics of confined concrete in partially FRP-confined circular columns remains unclear. In this paper, an experimental program consisting of fifteen column specimens was conducted and the test results were presented. A reliable three-dimensional (3D) finite element (FE) approach for modeling of partially FRP-confined circular columns was established. In the proposed FE approach, an accurate plastic-damage model for concrete under multiaxial compression is employed. The accuracy of the proposed FE approach was verified by comparisons between the numerical results and the test results. Numerical results from the verified FE approach were then presented to gain an improved understanding of the behavior of confined concrete in partially FRP-confined concrete columns.

Hydrothermal carbonization has been proven to improve the fuel properties of lowash straw biomass. To explore the effect of hydrothermal carbonization on high-ash straw biomass, the fuel properties and combustion behavior of hydrochar prepared by high-ash rice straw and corn straw at different temperature were studied. The results showed that increased reaction temperature could improve the C content, fixed carbon, heating value, and fuel ratios (FC/VM) in high-ash straw hydrochars, which is similar to the change trend of low-ash biomass. The hydrochar prepared at 260 °C has similar H/C and O/C atomic ratios and FC/VM to lignite. In addition, the highest energetic recovery efficiency is obtained at 200 °C. While at 180 °C, the comprehensive combustion characteristic index of the hydrochar is the best, which is 5.04 · 10-11 [min-2K-3] and 6.42 · 10-11 [min-2K-3]. In addition, the C content in the hydrochars at 180 °C was lower than the raw material, and the ash content increases with the reaction temperature, which is quite different from the low-ash biomass. In conclusion, the hydrothermal carbonization could improve the fuel quality of high-ash straw, while its ash content remains at a high level. [ABSTRACT FROM AUTHOR]