Search Results (376)

This work highlights the feasible fabrication of translucent ceramics from un-doped and Nd³⁺-doped BaLaLiWO₆ (BLLW) and BaLaNaWO₆ (BLNW) cubic tungstates using the Spark Plasma Sintering (SPS) method. Ceramics were sintered using pure-phase, homogeneous powders with submicron particle sizes, obtained via the solid-state reaction method. The present study investigated the microstructural, structural, and spectroscopic properties of both un-doped and Nd³⁺-doped sintered specimens. All the ceramic materials exhibited certain drawbacks that significantly contributed to their low transparency in both sample types. However, initial spectroscopic tests on sintered translucent ceramics doped with Nd³⁺ ions revealed promising properties, comparable to those of the powdered samples. Therefore, we believe that producing higher-quality ceramics would improve their spectroscopic properties. For that, further optimization of the manufacturing conditions is necessary. Full article

Rare-earth oxide (REO) nanoparticles (NPs)—such as cerium (CeO₂), samarium (Sm₂O₃), neodymium (Nd₂O₃), terbium (Tb₄O₇), and praseodymium (Pr₂O₃)—have demonstrated strong antimicrobial activity against multidrug-resistant bacteria. Their effectiveness is attributed to unique physicochemical properties, including oxygen vacancies and redox cycling, which facilitate the generation of reactive oxygen species (ROS) that damage microbial membranes and biomolecules. Additionally, electrostatic interactions with microbial surfaces and sustained ion release contribute to membrane disruption and long-term antimicrobial effects. REOs also inhibit bacterial enzymes, DNA, and protein synthesis, providing broad-spectrum activity against Gram-positive, Gram-negative, and fungal pathogens. However, dose-dependent cytotoxicity to mammalian cells—primarily due to excessive ROS generation—and nanoparticle aggregation in biological media remain challenges. Surface functionalization with polymers, peptides, or metal dopants (e.g., Ag, Zn, and Cu) can mitigate cytotoxicity and enhance selectivity. Scalable and sustainable synthesis remains a challenge due to high synthesis costs and scalability issues in industrial production. Green and biogenic routes using plant or microbial extracts can produce REOs at lower cost and with improved safety. Advanced continuous flow and microwave-assisted synthesis offer improved particle uniformity and production yields. Biomedical applications include antimicrobial coatings, wound dressings, and hybrid nanozyme systems for oxidative disinfection. However, comprehensive and intensive toxicological evaluations, along with regulatory frameworks, are required before clinical deployment. Full article

This study compared needle-plate electrohydrodynamic drying (EHD) at 20, 25, and 30 kV to natural drying (ND) of Astragalus membranaceus slices, analyzing drying characteristics, quality, and mechanisms. Discharge diagnostics revealed filamentous discharge, with reactive nitrogen/oxygen species concentration and ion wind speed increasing with voltage. Within the 20–30 kV range, drying rate and effective moisture diffusivity significantly increased with electric field strength. At 30 kV, drying rate was 1.73 times ND’s, and diffusivity was 5.1 times higher. Quality was optimal at 25 kV: rehydration rate was 1.18 times ND’s; calycosin and astragaloside IV contents were 1.38 and 1.14 times ND’s, respectively; shrinkage was reduced to 0.68 times ND’s; and browning was significantly inhibited (BI = 0.46 times ND’s), yielding the color closest to fresh samples. Polysaccharide content was slightly lower (0.97 times ND’s). In summary, EHD, particularly at 25 kV, markedly enhances drying efficiency and improves key quality attributes (rehydration, bioactive compound retention, color, reduced shrinkage), despite a minor negative effect on polysaccharides. This work clarifies the EHD mechanism and supports its application in drying traditional Chinese medicines. Full article

Photodynamic therapy (PDT) is a highly selective, clinically approved, minimally invasive technique that effectively eliminates cancer cells. Its effectiveness is limited by poor light penetration into tissue and the hydrophobic nature of photosensitizers, highlighting the need for new approaches to treatment. Here, a theranostic upconversion nanoplatform, consisting of a NaYF₄:Yb,Er,Tm,Fe core and a NaHoF₄ shell codoped with Yb, Nd, Gd and Tb ions, was designed to enhance PDT outcomes by integrating multi-wavelength upconversion luminescence, T₂-weighted magnetic resonance imaging (MRI) and PDT. The synthesized core–shell upconversion nanoparticles (CS-UCNPs) were coated with new verteporfin (VP)-conjugated alendronate-terminated poly(N,N-dimethylacrylamide-co-2-aminoethyl acrylate) [Ale-P(DMA-AEA)] grafted with poly(ethylene glycol) (PEG). Under 980 nm NIR irradiation, CS-UCNP@Ale-P(DMA-AEA)-PEG-VP nanoparticles generated reactive oxygen species (ROS) due to the efficient energy transfer between CS-UCNPs and VP. In a pilot preclinical study, intratumoral administration of nanoparticle conjugates to mice, followed by exposure to NIR light, induced necrosis of pancreatic tumor and suppressed its growth. Full article

The Zhilingtou Au-Mo-Pb-Zn polymetallic deposit is located in the southwestern Zhejiang Province, NE China, and is tectonically situated in the Shaoxing-Longquan uplift belt. Although previous studies have indicated that Au mineralization in this area occurred between 135 Ma and 145 Ma, evidence for coeval intrusive rocks has been lacking. Furthermore, it remains controversial whether the Au mineralization and (~113 Ma) Mo-Pb-Zn mineralization belong to the same magmatic-hydrothermal system. This study conducted comprehensive high-precision geochronological, petrochemical, and Sr-Nd isotopic analyses on the newly discovered granite porphyry intrusion in the mining area. The aim is to constrain the emplacement age of the intrusion, reveal the petrogenesis and source of ore-forming materials, and further discuss the mineralization mechanism. LA-ICP-MS zircon U-Pb dating results indicate that the granite porphyry was formed at 137.8 ± 0.95 Ma, which is broadly consistent with previously reported ages of Au mineralization. It is inferred that this intrusion may be related to a Au mineralization event at around 138 Ma. Geochemical characteristics show that the rock is peraluminous I-type granite, enriched in light rare earth elements (LREEs) and large ion lithophile elements (LILEs) and depleted in high field strength elements (HFSEs) such as Nb, Ta, and Ti, indicating an “island arc-type” geochemical signatures. Sr-Nd isotopic compositions (initial ⁸⁷Sr/⁸⁶Sr = 0.712364–0.712711; ε_Nd(t) = −13.9 to −13.4; two-stage Nd model ages T_DM2 = 1877–1908 Ma) suggest that the magma was derived from ancient crustal materials with the addition of mantle-derived components. Integrating existing geochronological, isotopic, and fluid inclusion evidence, it is proposed that the Zhilingtou deposit may have experienced two mineralization events: an early event (~138 Ma) involving Au-Ag mineralization related to the granite porphyry and a later event (~113 Ma) comprising Mo-Pb-Zn mineralization associated with a porphyry–epithermal system. Together, these events form a composite mineralization system. This study has important implications for refining regional metallogenic theories and guiding future ore exploration. Full article

Rare-earth oxides possess distinctive electronic configurations, tunable oxidation states, and inherent structural robustness, making them highly attractive for advanced energy storage applications. Among these, neodymium oxide (Nd₂O₃) stands out due to its high surface redox activity, structural stability, and favorable band alignment, enabling efficient charge storage in electrochemical devices. In this study, Nd₂O₃ electrodes were synthesized via a sol–gel method with systematically varied precursor concentrations (1 mM, 3 mM, and 5 mM) to elucidate the impact of synthesis on crystallinity, morphology, and electrochemical performance. X-ray diffraction (XRD) confirmed the formation of the hexagonal Nd₂O₃ phase, with the 3 mM sample (Nd-2) exhibiting the sharpest reflections, indicative of enhanced crystallinity and reduced lattice defects. X-ray photoelectron spectroscopy (XPS) revealed trivalent Nd species and both lattice and surface oxygen, providing abundant redox-active sites. Field Emission Scanning Electron Microscope (FE-SEM) showed Nd-2 possessed a hierarchically interconnected fibrous network decorated with fine granules, maximizing active surface area and facilitating rapid ion diffusion. Electrochemical testing demonstrated that Nd-2 achieved an areal capacitance of 20 F cm⁻², a diffusion-controlled pseudocapacitive contribution of ~84.9%, and retained 86.3% capacitance over 12,000 cycles. An asymmetric supercapacitor with Nd-2 and activated carbon delivered an energy density of 0.132 mWh cm⁻², power density of 1.8 mW/cm², and 81.1% capacitance retention over 7000 cycles. These results highlight the critical role of precursor concentration in tailoring structure and electrochemical performance, establishing Nd₂O₃ as a promising electrode for high-performance energy storage devices. Full article

Research on the Mesozoic–Cenozoic magmatism and the tectonic framework within the Lhasa Terrane is voluminous. However, the sparse documentation of Early Cretaceous magmatism in this region fuels ongoing debate over the prevailing tectonic regime during this time period (i.e., normal subduction vs. flat subduction). The present study investigates the Luerma pyroxenite and Boyun granitoid in the Western Lhasa Terrane through zircon U-Pb dating, whole-rock geochemistry, mineral chemistry, and Sr-Nd-Hf isotopes. The findings date the formation of Luerma pyroxenite at 115 Ma and Boyun granites at 113 Ma to the Early Cretaceous period (115–113 Ma). SiO₂ content of pyroxenite is relatively low (34.27–44.16 wt.%), characterized by an enrichment in large ion lithophile elements (LILEs), light rare earth elements (LREEs), and a depletion in heavy field strength elements (HSFEs), indicative of a metasomatic origin. The εNd (t) and εHf (t) values of the Early Cretaceous ultrabasic rocks range from +2.1 to +2.7 and −0.8 to +10.1, respectively, suggesting their derivation from an enriched mantle source with asthenospheric material incorporation. The Early Cretaceous granodiorites and their mafic enclaves belong to the high-K calc-alkaline series, and show enrichment in LILEs (e.g., Rb, Ba, U, and Th) and depletion in HFSEs (e.g., Nb, Ta, Ti, and Zr). The acidic rocks and their developed mafic enclaves exhibit the geochemical characteristics of trace elements found in island arc magmas. Their εNd (t) values are (−6.0–−5.0), while their εHf (t) values are (−11.7–−1.8); the MMEs εHf (t) values are (−4.1–+0.9). In summary, the Early Cretaceous pyroxenite in the Gangdese Belt originated from a combination of asthenospheric and enriched lithospheric mantle melts, while the granitoids were generated by partial melting of the mantle wedge, a process driven by metasomatism resulting from the slab-derived fluids. At the same time, heat from upwelling mantle-derived melts induced the partial melting of lower crustal materials, leading to the formation of acidic magmas through varying degrees of mixing with basic magmas. This study suggests that Early Cretaceous magmatic activity occurred within a northward subduction setting, characterized by the rotation and fragmentation of the Neo-Tethys oceanic crust. Full article

The rational design of transition metal oxides with tailored electronic structures and defect chemistries is critical for advancing high-performance supercapacitors. Herein, we report the engineering of cobalt oxide (Co₃O₄) gels through controlled sol–gel synthesis and rare earth (RE) incorporation using neodymium (Nd), gadolinium (Gd), and dual neodymium/gadolinium (Nd/Gd) doping. X-ray diffraction (XRD) confirmed the preservation of the cubic spinel structure with systematic peak shifts and broadening, evidencing lattice strain, oxygen vacancy generation, and defect enrichment. Field-emission scanning electron microscopy (FE-SEM) analyses revealed distinct morphological evolution from compact nanoparticle assemblies in pristine Co₃O₄ to highly porous, interconnected frameworks in Nd/Gd–Co₃O₄ (Nd/Gd-Co). X-ray photoelectron spectroscopy (XPS) verified the stable incorporation of RE ions, accompanied by electronic interaction with the Co–O matrix and enhanced oxygen defect states. Electrochemical measurements demonstrated that the Nd/Gd–Co electrode achieved a remarkable areal capacitance of 25 F/cm² at 8 mA/cm², superior ionic diffusion coefficients, and the lowest equivalent series resistance (0.26 Ω) among all samples. Long-term cycling confirmed 84.35% capacitance retention with 94.46% coulombic efficiency after 12,000 cycles. Furthermore, the asymmetric pouch-type supercapacitor (APSD) constructed with Nd/Gd–Co as the positive electrode and activated carbon as the negative electrode delivered a wide operational window of 1.5 V, an areal capacitance of 140 mF/cm², an energy density of 0.044 mWh/cm², and 89.44% retention after 7000 cycles. These findings establish Nd/Gd-Co gels as robust and scalable electrode materials and demonstrate that RE co-doping is an effective strategy for bridging high energy density with long-term electrochemical stability in asymmetric supercapacitors. Full article

The Altyn Tagh Fault plays a critical role in understanding the tectonic evolution of the northern margin of the Tibetan Plateau. However, considerable debate persists regarding its activity and deformation history. This study investigates volcanic rocks from the Beidayao-Jianquanzi-Hanxia-Hongliuxia area in the eastern segment of the fault. By employing zircon U-Pb dating, whole-rock geochemistry, and Sr-Nd isotope analysis, we aim to elucidate their petrogenesis and tectonic setting, thereby providing new insights into the crustal evolution of the eastern Altyn Tagh Fault. Zircon U-Pb dating of the Hongliuxia rhyolite yields a weighted mean ²⁰⁶Pb/²³⁸U age of 106.6 ± 0.6 Ma, indicating an Early Cretaceous eruption. Geochemically, the western part of the study area (Beidayao and Jianquanzi) is dominated by basalts that exhibit significant enrichment in large ion lithophile elements and light rare earth elements, together with high Nb concentrations (>20 ppm), as well as high Nb/La (0.64–1.12) and Nb/U (29.8–35.42) ratios, consistent with the characteristics of high-Nb basalt. In contrast, the eastern area (Hanxia and Hongliuxia) is characterized by andesitic rocks that display typical continental arc affinities, marked by enrichment in Th, U, and Pb and depletion in Nb, Ta, and Ti. Isotopically, the basalts show initial ⁸⁷Sr/⁸⁶Sr ratios of 0.706–0.707 and ε_Nd (t) values ranging from −3.2 to 0.8, whereas the andesites possess more radiogenic Sr isotopic compositions, with (⁸⁷Sr/⁸⁶Sr)_i ratios of 0.710–0.717, and more negative ε_Nd (t) values from −11.4 to −1.5, suggesting derivation from an enriched mantle source. Integrating geochemical data with regional geological records, we propose that the eastern part of the Altyn Fault experienced a significant intracontinental extensional setting during the Early Cretaceous, where asthenospheric mantle upwelling played a key role in the generation of the volcanic rocks. This study provides key petrological and geochemical constraints on Early Cretaceous deformation and activity along the Altyn Tagh Fault, and also offers a valuable reference for understanding the evolution of similar fault systems. Full article

Confronted with increasing global food demands, diminishing arable land, and climate volatility, controlled-environment agriculture with advanced red and far-red LED lighting can enhance photosynthesis and optimize plant growth. This investigation reports the generation of a Mn⁴⁺/Nd³⁺ co-doped Y₂SiO₅ phosphor with a Nd³⁺ concentration ranging from 0.1 to 2.5 mol% via a solid-state synthesis method, aiming to enhance red and far-red emission for plant cultivation LEDs. For the Y₂SiO₅:Mn⁴⁺ (1 mol%), Nd³⁺ (2 mol%) phosphor, the phase integrity, nanostructured morphology, elemental mapping, and vibrational characteristics were examined using XRD, Rietveld analysis, FTIR, SEM, and EDX. Nd³⁺ ions act as near-infrared excitation mediators, ensuring efficient Nd³⁺ → Mn⁴⁺ energy transfer upon 808 nm excitation, and this leads to pronounced red photoluminescence from Mn⁴⁺ ions that covers the range of 640–710 nm, exhibiting strong emission peaks centered at 650nm, 663nm, and 685nm, coinciding with the absorption band of phytochromes and chlorophyll. The optimal emission intensity was accomplished for a Nd³⁺ doping concentration of 2 mol%, beyond which concentration quenching occurred. The material produced a strong, concentrated deep red emission with CIE coordinates near (0.73, 0.27) and a high color purity of 98.96%, making it well-suited for photosynthetic activation. A phosphor-integrated red pc-LED was fabricated, and Tulsi plants were grown under this LED during the winter in Meghalaya, a period critical for plant growth due to the low ambient light. Over a 30-day period, the plants exhibited enhanced height and leaf development, demonstrating the practical potential of Mn⁴⁺/Nd³⁺ co-doped Y₂SiO₅ for energy-efficient, wavelength-optimized horticultural lighting. Full article

The Permian Xiashihezi Formation in the Ordos Basin is a typical tight sandstone gas reservoir, which is characterized by low porosity and strong heterogeneity. Diagenesis plays a crucial role in controlling reservoir quality. However, the multiple phases and types of diagenetic processes throughout geological history make the compaction mechanisms highly complex. This study employed a high-temperature and high-pressure diagenesis simulation system to conduct geological simulation experiments. Typical reservoir samples from the 2nd Member of the Permian Xiashihezi Formation were selected for these simulations. The experiments replicated the diagenetic evolution of the reservoirs under various temperature, pressure, and fluid conditions, successfully reproducing the diagenetic sequences. The diagenetic sequence included early-stage porosity reduction through compaction, early carbonate cementation, quartz overgrowth, chlorite rim formation, feldspar dissolution, and late-stage illite and quartz cementation. Mechanical compaction is the primary factor reducing reservoir porosity, exhibiting a distinct four-stage porosity reduction pattern: (1) continuous burial stage (>4000 m); (2) stagnation stage of burial (3900 m–4100 m); (3) the secondary continuous burial stage (>5000 m); (4) tectonic uplift stage (3600 m). The experiments confirmed that the formation of various authigenic minerals is strictly controlled by temperature, pressure, and fluid chemistry. Chlorite rims formed in an alkaline environment enriched with Fe²⁺ and Mg²⁺ (simulated temperatures of 280–295 °C), effectively inhibiting quartz overgrowth. Illite appeared at higher temperatures (>300 °C) in platy or fibrous forms. Feldspar dissolution was noticeable upon injection of acidic fluids (simulated organic acids), providing material for authigenic quartz and kaolinite. The key mineral composition significantly impacts reservoir diagenesis. The dissolution released Mg²⁺ and Fe²⁺ ions, crucial for forming early chlorite rims in the overlying sandstones, confirming the importance of inter-strata interactions in “source-facies coupling.” Through physical simulation methods, this study deepened the understanding of the diagenetic evolution and compaction mechanisms of tight sandstones. This provides significant experimental evidence and theoretical support for predicting “sweet spot” reservoirs in the area. Full article

The rare earth (RE) aqua 4-nitrophenylacetate (4npa) complexes {[RE(4npa)₃(H₂O)₂]·2H₂O}_n (RE = La (1La), Nd (2Nd)), [Ce(4npa)₃(H₂O)₂]_n (3Ce), and {[RE₂(4npa)₆(H₂O)]·2H₂O}_n (RE = Gd (4Gd), Dy (5Dy), Y (6Y), Er (7Er), Yb (8Yb)) were synthesised by salt metathesis reactions of RE^III chlorides or nitrates with sodium 4-nitrophenylacetate Na(4npa) in aqueous ethanol. The structures of all the complexes were determined by single-crystal X-ray diffraction (SCXRD) except for RE = 4Gd, which was determined to be isomorphous with the 5Dy and 7Er complexes by X-ray powder diffraction (XRPD). All the complexes crystallise as one-dimensional polymers linked by bridging carboxylates. Complexes (1La–3Ce) have mononuclear repeating units with two coordinated waters and ten coordinate RE ions, 1La and 2Nd also have two waters of crystallization, but 3Ce has none. By contrast, complexes (4Gd–8Yb) have binuclear repeating units with a single coordinated water. Isomorphous 5Dy and 7Er have one nine coordinate and one eight coordinate metal ion, whilst isomorphous 6Y and 8Yb have two eight coordinate RE ions. In some cases, bulk powders have structures different from the corresponding single crystals. For example, bulk 1La is isomorphous with 3Ce owing to the loss of water of crystallization, and 8Yb exhibits coordination isomerism between single crystals and microcrystalline powder. Weight loss corrosion tests revealed that {[Dy₂(4npa)₆(H₂O)]·2H₂O}_n (5Dy) has the greatest inhibition efficiency (89%) of the complexes (1La–8Yb). The activities are comparable to those of the corresponding 4-hydroxyphenylacetates (4hpa) and far superior to those of 2-hydroxyphenylacetates (2hpa) and the unsubstituted phenylacetates. Whilst the coordination numbers generally decline with the lanthanoid contraction, there are deviations around 5Dy, 6Y, 7Er, and 8Yb, and the corrosion inhibition is optimised with a midrange size. Full article

Sodium metal batteries (SMBs) with ceramic solid electrolytes offer a promising route to improve the energy density of conventional Na-ion batteries (SIBs). Silicate-based ceramics have recently gained attention for their favourable properties, including better ionic conduction and wider stability windows. In this study, 10% Pr³⁺ and Nd³⁺ were doped into sodium gadolinium silicate ceramics to examine the effects on phase purity, ionic conductivity, and interfacial compatibility with sodium metal anodes. The materials were synthesized via solid-state methods and sintered at 950–1075 °C to study the impact of sintering temperature on densification and microstructure. Na₅Gd_0.9Pr_0.1Si₄O₁₂ (NGPS) and Na₅Gd_0.9Nd_0.1Si₄O₁₂ (NGNS) sintered at 1075 °C showed the highest room temperature total ionic conductivities of 1.64 and 1.74 mS cm⁻¹, respectively. The highest critical current density of 0.5 mA cm⁻² is achieved with a low interfacial area-specific resistance of 29.47 Ω cm² for NGPS and 22.88 Ω cm² for NGNS after Na plating/stripping experiments. These results highlight how doping enhances phase purity, ionic conductivity, and interfacial stability of silicates with Na metal anodes. Full article

Rare earth elements (REEs) are critical for advanced technologies, with neodymium and praseodymium being essential to high-performance permanent magnets. The separation of these adjacent lanthanides represents a significant challenge due to their nearly identical chemical properties, with traditional chitosan surfaces exhibiting limited discrimination between chemically similar elements. Current separation methods require multiple processing steps and cannot maintain predetermined compositional ratios. Engineered polymer interfaces with controlled binding site distribution represents a critical advancement for selective separation, but achieving ratio-controlled extraction of adjacent elements remains challenging. Here, we demonstrate a novel interface engineering approach using alkali/urea dissolution to restructure chitosan networks, creating dual-template alkali/urea chitosan hydrogels (NdPr-AUCH) for simultaneous selective co-extraction of Nd(III) and Pr(III). We show that the dissolution–reformation process enables templated Nd:Pr selectivity ratios (1:1, 2:1, and 4:1) that directly correspond to synthesis compositions. NdPr-AUCH-11 achieved maximum uptake capacities of 19.85 mg/g for Nd(III) and 16.89 mg/g for Pr(III), while NdPr-AUCH-41 maintained 3.07:1 Nd:Pr selectivity in competitive environments. Thermodynamic analyses reveal consistently lower energy requirements for Nd(III) binding compared to Pr(III), demonstrating how interface engineering amplifies coordination differences between adjacent lanthanides. This work represents the first demonstration of ratio-controlled extraction of adjacent lanthanides within a single polymer matrix, advancing interface-engineered materials for selective rare earth recovery. Full article