Search Results (43)

Optimizing thermoelectric (TE) performance in two-dimensional materials has emerged as a pivotal strategy for sustainable energy conversion. This study systematically investigates the regulatory mechanisms of uniaxial strain (−2% to +2%), temperature (300–800 K), and out-of-plane electric fields (0–1.20 eV/Å) on the thermoelectric properties of monolayer MoS₂ via first-principles calculations combined with Boltzmann transport theory. Key findings reveal that uniaxial strain modulates the bandgap (1.56–1.86 eV) and carrier transport, balancing the trade-off between the Seebeck coefficient and electrical conductivity. Temperature elevation enhances carrier thermal excitation, boosting the power factor to 28 × 10¹⁰ W·m⁻¹·K⁻²·s⁻¹ for p-type behavior and 27 × 10¹⁰ W·m⁻¹·K⁻²·s⁻¹ for n-type behavior at 800 K. The breakthrough lies in the exceptional suppression of lattice thermal conductivity (κ₁) by out-of-plane electric fields—at 1.13 eV/Å, κ₁ is reduced to single-digit values (W·m⁻¹·K⁻¹), driving ZT to ~4 for n-type MoS₂ at 300 K. This work demonstrates that synergistic engineering of strain, temperature, and electric fields effectively decouples the traditional trade-off among the Seebeck coefficient, conductivity, and thermal conductivity, providing a core optimization pathway for 2D thermoelectric materials via electric field-mediated κ₁ regulation. Full article

Severe polysulfide shuttling and sluggish redox kinetics critically hinder lithium–sulfur (Li-S) battery commercialization. In this study, a multifunctional diatomite (DE)/TiO₂/MoS₂/N-doped carbon nanofiber (NCNF) composite separator was fabricated via hydrothermal synthesis, electrospinning, and carbonization. DE provides dual polysulfide suppression, encompassing microporous confinement and electrostatic repulsion. By integrating synergistic catalytic effects from TiO₂ and MoS₂ nanoparticles, which accelerate polysulfide conversion, and conductive NCNF networks, which facilitate rapid charge transfer, this hierarchical design achieves exceptional electrochemical performance: a 1245.6 mAh g⁻¹ initial capacity at 0.5 C and 65.94% retention after 200 cycles. This work presents a rational multi-component engineering strategy to suppress shuttle effects in high-energy-density Li-S batteries. Full article

The key to selectively cleaving C–O bonds in lignin to produce high-value aromatic chemicals lies in the development of efficient and stable catalysts. In this study, a heterostructured catalyst with N-doped carbon-supported Co and dual-phase Mo_xC nanoparticles was prepared via the in situ pyrolysis of a Co–Mo–N precursor. The dual-phase α-MoC/β-Mo₂C heterostructure is adjusted by varying the Co:Mo ratio to affect the structure and electronic properties of the catalyst. The heterostructures bring about enhanced electron transfer from Co to Mo, which promotes hydrogen dissociation over the Co sites, significantly improving the catalyst’s hydrogenolysis activity and stability. The optimal catalyst with Co₁Mo_xC@NC exhibits excellent hydrogenolysis activity; under the optimal reaction conditions (260 °C, 1 MPa H₂, 3 h), the yield of aromatic monomers reaches 28.5%. Such prominent performance not only benefits from the numerous α-MoC/β-Mo₂C hetero-interfaces that offer abundant active sites for hydrogen dissociation, but also should be ascribed to the strong synergistic effect between Co and Mo. Full article

In this paper, the natural waste pinecone as a carbon precursor for the generation of satisfactory sulfur host materials in lithium–sulfur batteries was realized by introducing molybdenum carbide nanoparticles into the derived carbon structure. The conductive pinecone-derived carbon doped with N, O reveals an expansive specific surface area, facilitating the accommodation of a higher sulfur load. Moreover, the integration of Mo₂C nanoparticles also significantly enhances its chemical affinity and catalytic capacity for polysulfides (LiPSs) to alleviate the shuttle effect and accelerate sulfur redox conversion. As a result, the WPC-Mo₂C/S electrode displays excellent electrochemical performance, including a low capacity decay rate of 0.074% per cycle during 600 cycles at 1 C and an outstanding rate capacity (631.2 mAh g⁻¹ at 3 C). Moreover, with a high sulfur loading of 5.5 mg cm⁻², the WPC-Mo₂C/S electrode shows a high area capacity of 5.1 mAh cm⁻² after 60 cycles at 0.2 C. Full article

This study investigates the effectiveness of micron- and nano-sized molybdenum disulfide (MoS₂) particles as additives in lithium (Li) grease under electrified conditions. By systematically applying electric current and high temperatures as experimental parameters, we evaluated the frictional and wear performance of the grease formulations. Our results showed that micron MoS₂ (M-MoS₂) particles outperform their nano counterparts in reducing friction in the range of room temperature to 40 °C. Meanwhile, at 80 °C, nano-sized MoS₂ (N-MoS₂) particles provide better surface protection. The superior performance of M-MoS₂ is attributed to their particle size, which improves the ability to form a more stable and robust lubricating film under the given electrical conditions. In terms of wear, both MoS₂-added greases showed substantial improvements, with a 93% reduction in wear at 40 °C and an 85% at 80 °C under an applied 3 A current. Surface characterization revealed that M-MoS₂ resulted in a smoother surface with less severe pitting and melted pools compared to the base grease. EDX analysis showed the existence of oxygen, molybdenum, and sulfur in M-MoS₂, indicating the presence and stability of MoS₂ on the wear track. These findings suggest that MoS₂ additives have great potential for improving the efficiency and durability of lubricants in electrically and thermally demanding applications. Full article

In order to study the geochemical characteristics of coal in the Ningwu Coalfield of Shanxi Province and the coal-forming environments reflected by it, a detailed geochemical study was carried out on the No. 5 coal of the Zhaokai Mine. The results show that the content of major-element oxides SiO₂ and Al₂O₃ is high. The trace elements Ni, Nb, Mo, Cd, Sn, Hf, Ta, W, Th, and U are slightly enriched, while the elements Li and Zr are enriched, indicating an overall LREY enrichment type in the samples. Elemental parameters suggest that the sedimentary environment in the study area is continental sedimentary, and the whole environment is reductive. The macerals in the coal samples are mainly vitrinite, with an average vitrinite reflectance (R_o) of 0.744%. The distribution range of n-alkanes in the coal samples is from n-C₁₄~n-C₃₂, with the main peak carbons being n-C₂₄ and n-C₂₅, showing the post-single-peak type distribution pattern. The average odd–even predominance index (OEP) is 0.40, the average of the light and heavy hydrocarbons ratio (${\displaystyle \sum {\mathrm{C}}_{21}^{-}}/{\displaystyle \sum {\mathrm{C}}_{22}^{+}}$) is 0.42, and the average of Pr/n-C₁₇ and Ph/n-C₁₈ are 1.08 and 0.23, respectively. The coal samples also contain various aromatic hydrocarbons, mainly from the naphthalene- and phenanthrene-series compounds. Biomarker parameters indicate that the parent material of the coal samples in the study area is mainly continental higher plants. The maturity is low, and the coal-forming environment is a reduction environment. This study of the No. 5 coal’s geochemical characteristics has laid a foundation for the efficient, green, and comprehensive exploitation of coal resources in this region, and has also provided an important basis for the sustainable development of coal resources. Full article

The main objective of this study was to compare the effectiveness of an innovative multi-nutrient fertiliser (PRO complete) applied foliarly with a standard fertiliser (TRA complete) in triticale crops. PRO complete contained macronutrients (N, P, K), micronutrients (B, Cu, Fe, Mn, Mo, Zn, with Fe and Zn complexed with amino acids), and trace elements (Cr, I, Li, Se—combined with plant extracts). TRA complete had the same quantitative composition, but the micronutrients and trace elements were in mineral form or in complex with EDTA. The experiment was conducted on triticale grown in a soil culture in a growing hall. The triticale yield and quality were determined. The fertilisers had no significant effect on straw yield and macronutrient (N, P, K, Mg, Ca) content in straw and grain. They caused a significant increase in grain yield, but PRO complete was more effective, also in terms of increasing the content of some micronutrients, particularly in straw. Both fertilisers increased the content of Cr, Li, and Se in straw. The application of the fertilisers contributed to some extent to triticale biofortification. In conclusion, the use of foliar multi-compound fertilisers is a beneficial choice for optimising crop yield and quality. However, their chemical composition and dosage should be further developed. Full article

Polyanionic structures, (MO₄)ⁿ⁻_, can be beneficial to the transport of lithium ions by virtue of the open three-dimensional frame structure. However, an unstable interface suppresses the life of the (MO₄)ⁿ⁻-based anode. In this study, MnWO₄@C nanorods with dense nanocavities have been synthesized through a hydrothermal route, followed by a chemical deposition method. As a result, the MnWO₄@C anode exhibits better cycle and rate performance than MnWO₄ as a Li-ion battery; the capacity is maintained at 718 mAh g⁻¹ at 1000 mA g⁻¹ after 400 cycles because the transport of lithium ions and the contribution of pseudo-capacitance are increased. Generally, benefiting from the carbon shell and electrolyte additive (e.g., FEC), the cycle performance of the MnWO₄@C electrode is also effectively improved for lithium storage. Full article

Two mixed peri-substituted phosphine-chlorostibines, Acenap(PiPr₂)(SbPhCl) and Acenap(PiPr₂)(SbCl₂) (Acenap = acenaphthene-5,6-diyl) reacted cleanly with Grignard reagents or nBuLi to give the corresponding tertiary phosphine-stibines Acenap(PiPr₂)(SbRR’) (R, R’ = Me, iPr, nBu, Ph). In addition, the Pt(II) complex of the tertiary phosphine-stibine Acenap(PiPr₂)(SbPh₂) as well as the Mo(0) complex of Acenap(PiPr₂)(SbMePh) were synthesised and characterised. Two of the phosphine-stibines and the two metal complexes were characterised by single-crystal X-ray diffraction. The peri-substituted species act as bidentate ligands through both P and Sb atoms, forming rather short Sb-metal bonds. The tertiary phosphine-stibines display through-space J(CP) couplings between the phosphorus atom and carbon atoms bonded directly to the Sb atom of up to 40 Hz. The sequestration of the P and Sb lone pairs results in much smaller corresponding J(CP) being observed in the metal complexes. QTAIM (Quantum Theory of Atoms in Molecules) and EDA-NOCV (Energy Decomposition Analysis employing Naturalised Orbitals for Chemical Valence) computational techniques were used to provide additional insight into a weak n(P)→σ*(Sb-C) intramolecular bonding interaction (pnictogen bond) in the phosphine-stibines. Full article

Background: Multiple organ dysfunction syndrome (MODS) is common in intensive care units (ICUs) and is associated with high mortality. Although there have been multiple investigations into a multitude of organ dysfunctions, little is known about the role of liver dysfunction. In addition, clinical and laboratory findings of liver dysfunction may occur with a significant delay. Therefore, the aim of this study was to investigate whether a liver function test, based on indocyanine green (ICG)-clearance, contains prognostic information for patients in the early phase of MODS. Methods: The data of this analysis were based on the MODIFY study, which included 70 critically ill patients of a tertiary medical ICU in the early phase of MODS (≤24 h after diagnosis by an APACHE II score ≥ 20 and a sinus rhythm ≥ 90 beats per minute, with the following subgroups: cardiogenic (cMODS) and septic MODS (sMODS)) over a period of 18 months. ICG clearance was characterized by plasma disappearance rate = PDR (%/min); it was measured non-invasively by using the LiMON system (PULSION Medical Systems, Feldkirchen, Germany). The PDR was determined on the day of study inclusion (baseline) and after 96 h. The primary endpoint of this analysis was 28-day mortality. Results: ICG clearance was measured in 44 patients of the MODIFY trial cohort, of which 9 patients had cMODS (20%) and 35 patients had sMODS (80%). Mean age: 59.7 ± 16.5 years; 31 patients were men; mean APACHE II score: 33.6 ± 6.3; 28-day mortality was 47.7%. Liver function was reduced in the total cohort as measured by a PDR of 13.4 ± 6.3%/min At baseline, there were no relevant differences between survivors and non-survivors regarding ICG clearance (PDR: 14.6 ± 6.1%/min vs. 12.1 ± 6.5%/min; p = 0.21). However, survivors showed better liver function than non-survivors after 96 h (PDR: 21.9 ± 6.3%/min vs. 9.2 ± 6.3%/min, p < 0.05). Consistent with these findings, survivors but not non-survivors show a significant improvement in the PDR (7.3 ± 6.3%/min vs. −2.9 ± 2.6%/min; p < 0.01) within 96 h. In accordance, receiver-operating characteristic curves (ROCs) at 96 h but not at baseline show a link between the PDR and 28-day mortality (PDR at 96 h: AUC: 0.87, 95% CI: 0.76–0.98; p < 0.01. Conclusions: In our study, we found that ICG clearance at baseline did not provide prognostic information in patients in the early stages of MODS despite being reduced in the total cohort. However, improvement of ICG clearance 96 h after ICU admission is associated with reduced 28-day mortality. Full article

This paper presents a detailed design of an inexpensive, simple, and scalable Distributed Sensor Network (DSN). Each sensor’s hardware consists of a Raspberry Pi 3 Model B microprocessor, a specifically designed and factory-made Printed Circuit Board (PCB), an Uninterruptible Power Supply (UPS) Hat based on a High-Capacity Lithium Polymer battery (LiPo), a Power over Ethernet Splitter, a GPS receiver, and a LoRaWAN module. Each sensor is built to capture GPS, Wi-Fi, and Bluetooth signals and sends this information to a network controller implementing a LoRaWAN gateway. Each sensor’s software is developed so that all applications run on top of a Linux operating system. The layer above it includes system daemon applications, such as Air-mon, HCI tools, GPSd, and networking support. An SQLite database sits on top of the daemon applications and records the captured information. After the DSN was successfully tested, it was deployed in a research study. The novelty of this study is that this was the first time that a DSN was used in high schools to detect leakage from IoT devices to educate students about cyber safety. Full article

In this study, the use of anionic polymerization for the synthesis of living poly(dimethylsiloxane) or PDMS-Li⁺, as well as poly(2-vinylpyridine) or P2VP-Li⁺ homopolymers, and the subsequent use of chlorosilane chemistry in order for the two blocks to be covalently joined leading to PDMS-b-P2VP copolymers is proposed. High vacuum manipulations enabled the synthesis of well-defined materials with different molecular weights (${\overline{\mathsf{{\rm M}}}}_{\mathrm{n}}$, from 9.8 to 36.0 kg/mol) and volume fraction ratios (φ, from 0.15 to 0.67). The ${\overline{\mathsf{{\rm M}}}}_{\mathrm{n}}$ values, dispersity indices, and composition were determined through membrane/vapor pressure osmometry (MO/VPO), size exclusion chromatography (SEC), and proton nuclear magnetic resonance spectroscopy (¹H NMR), respectively, while the thermal transitions were determined via differential scanning calorimetry (DSC). The morphological characterization results suggested that for common composition ratios, lamellar, cylindrical, and spherical phases with domain periodicities ranging from approximately 15 to 39 nm are formed. A post-polymerization chemical modification reaction to quaternize the nitrogen atom in some of the P2VP monomeric units in the copolymer with the highest P2VP content, and the additional characterizations through ¹H NMR, infrared spectroscopy, DSC, and contact angle are reported. The synthesis, characterization, and quaternization of the copolymer structure are important findings toward the preparation of functional materials with enhanced properties suitable for various nanotechnology applications. Full article

Ammonia (NH₃), which has a 17.7 wt% gravimetric hydrogen density, has been considered as a potential hydrogen storage material. This study looked at the thermocatalytic decomposition of NH₃ using a bulk Mo₂N catalyst that was boosted by alkali metals (AM: 5 wt% Li, K, Cs). The K-Mo₂N catalyst outperformed all other catalysts in this experiment in terms of catalytic performance. At 6000 h⁻¹ GHSV, 100% conversion of NH₃ was accomplished using the K-Mo₂N, Cs-Mo₂N, and Mo₂N catalysts. However, when compared to other catalysts, K-Mo₂N had the highest activity, or 80% NH₃ conversion, at a lower temperature, or 550 °C. The catalytic activity exhibited the following trend for the rate of hydrogen production per unit surface area: K-Mo₂N > Cs-Mo₂N > Li-Mo₂N > Mo₂N. Up to 20 h of testing the K-Mo₂N catalyst at 600 °C revealed no considerable deactivation. Full article

The photosynthetic pigments, protein, macro and microelements concentrations, and fatty acids composition of Salvinia natans, a free-floating aquatic plant, were analyzed after exposure to Hoagland nutrient solution containing 1, 3, and 5 mg/L Li. The Li content of Salvinia natans grew exponentially with the Li concentration in the Hoagland nutrient solution. The exposure to Li did not induce significant changes in Na, Mg, K, Cu, and Zn content but enhanced the Ba, Cr, Mn, Ni and Mo absorption in Salvinia natans. The most abundant fatty acids determined in oils extracted from Salvinia natans were C16:0, C18:3(n6), C18:2(n6), and C18:3(n3). The photosynthetic pigments did not change significantly after exposure to Li. In contrast, chlorophyll and protein content decreased, whilst monounsaturated and polyunsaturated fatty acids content increased after the exposure to 1 mg/L Li. The results indicated that Salvinia natans exposed to low Li concentrations may be a good source of minerals, omega 6 and omega 3. Full article

At present, it is still a challenge to prepare multifunctional composite nanomaterials with simple composition and favorable structure. Here, multifunctional Fe₃O₄@nitrogen-doped carbon (N-C) nanocomposites with hollow porous core-shell structure and significant electrochemical, adsorption and sensing performances were successfully synthesized through the hydrothermal method, polymer coating, then thermal annealing process in nitrogen (N₂) and lastly etching in hydrochloric acid (HCl). The morphologies and properties of the as-obtained Fe₃O₄@N-C nanocomposites were markedly affected by the etching time of HCl. When the Fe₃O₄@N-C nanocomposites after etching for 30 min (Fe₃O₄@N-C-3) were applied as the anodes for lithium-ion batteries (LIBs), the invertible capacity could reach 1772 mA h g⁻¹ after 100 cycles at the current density of 0.2 A g⁻¹, which is much better than that of Fe₃O₄@N-C nanocomposites etched, respectively, for 15 min and 45 min (948 mA h g⁻¹ and 1127 mA h g⁻¹). Additionally, the hollow porous Fe₃O₄@N-C-3 nanocomposites also exhibited superior rate capacity (950 mA h g⁻¹ at 0.6 A g⁻¹). The excellent electrochemical properties of Fe₃O₄@N-C nanocomposites are attributed to their distinctive hollow porous core-shell structure and appropriate N-doped carbon coating, which could provide high-efficiency transmission channels for ions/electrons, improve the structural stability and accommodate the volume variation in the repeated Li insertion/extraction procedure. In addition, the Fe₃O₄@N-C nanocomposites etched by HCl for different lengths of time, especially Fe₃O₄@N-C-3 nanocomposites, also show good performance as adsorbents for the removal of the organic dye (methyl orange, MO) and surface-enhanced Raman scattering (SERS) substrates for the determination of a pesticide (thiram). This work provides reference for the design and preparation of multifunctional materials with peculiar pore structure and uncomplicated composition. Full article