82 research outputs found
Compositionally tuned NixSn alloys as anode materials for lithium-ion and sodium-ion batteries with a high pseudocapacitive contribution
Nickel tin alloy nanoparticles (NPs) with tuned composition NixSn (0.6 ≤ x ≤ 1.9) were synthesized by a solution-based procedure and used as anode materials for Li-ion batteries (LIBs) and Na-ion batteries (SIBs). Among the compositions tested, Ni₀₉Sn-based electrodes exhibited the best performance in both LIBs and SIBs. As LIB anodes, Ni₀₉Sn-based electrodes delivered charge-discharge capacities of 980 mAh g⁻¹ after 340 cycles at 0.2 A g⁻¹ rate, which surpassed their maximum theoretical capacity considering that only Sn is lithiated. A kinetic characterization of the charge-discharge process demonstrated the electrode performance to be aided by a significant pseudocapacitive contribution that compensated for the loss of energy storage capacity associated to the solid-electrolyte interphase formation. This significant pseudocapacitive contribution, which not only translated into higher capacities but also longer durability, was associated to the small size of the crystal domains and the proper electrode composition. The performance of NixSn-based electrodes toward Na-ion storage was also characterized, reaching significant capacities above 200 mAh g⁻¹ at 0.1 A g⁻¹ but with a relatively fast fade over 120 continuous cycles. A relatively larger pseudocapacitive contribution was obtained in Ni Sn-based electrodes for SIBs when compared with LIBs, consistently with the lower contribution of the Na ion diffusion associated to its larger size
Co–Sn nanocrystalline solid solutions as anode materials in lithium-ion batteries with high pseudocapacitive contribution
Co–Sn solid-solution nanoparticles with Sn crystal structure and tuned metal ratios were synthesized by a facile one pot solution-based procedure involving the initial reduction of a Sn precursor followed by incorporation of Co within the Sn lattice. These nanoparticles were used as anode materials for Li-ion batteries. Among the different compositions tested, Co0.7Sn and Co0.9Sn electrodes provided the highest capacities with values above 1500 mAh¿g-1 at a current density of 0.2 A¿g-1 after 220 cycles, and up to 800 mAh¿g-1 at 1.0 A¿g-1 after 400 cycles. Up to 81¿% pseudocapacitance contribution was measured for these electrodes at a sweep rate of 1.0 mV¿s-1, thereby indicating fast kinetics and long durability. The excellent performance of Co–Sn nanoparticle alloy-based electrodes was attributed to both the small size of the crystal domains and their suitable composition, which buffered volume changes of Sn and contributed to a suitable electrode restructuration.Postprint (author's final draft
Relationships between Physical, Mechanical and Acoustic Properties of Asphalt Mixtures Using Ultrasonic Testing
Ultrasonic testing can be used for a nondestructive and rapid determination of material properties. In this study, twelve asphalt mixture samples of four different types were fabricated and used in conventional material property tests and two ultrasonic wave tests. Physical properties such as bulk specific gravity and air void content, mechanical properties such as dynamic modulus and phase angle, and acoustic properties such as wave velocity were measured. Relationships between these properties were established and analyzed as a tool for the future material property determination. In addition, the dynamic modulus and phase angle, measured in a standard laboratory test, were used to construct two master curve models to predict their values at arbitrary temperatures and frequencies. Furthermore, a theoretical model for wave velocity in a linear isotropic viscoelastic material was utilized with measured density, Poisson’s ratio, phase angle and ultrasonic wave velocity to predict the dynamic modulus. Good agreement has been achieved between laboratory measurements and model predictions. It indicates that ultrasonic testing can serve as a rapid method for material property determination
Relationships between Physical, Mechanical and Acoustic Properties of Asphalt Mixtures Using Ultrasonic Testing
Ultrasonic testing can be used for a nondestructive and rapid determination of material properties. In this study, twelve asphalt mixture samples of four different types were fabricated and used in conventional material property tests and two ultrasonic wave tests. Physical properties such as bulk specific gravity and air void content, mechanical properties such as dynamic modulus and phase angle, and acoustic properties such as wave velocity were measured. Relationships between these properties were established and analyzed as a tool for the future material property determination. In addition, the dynamic modulus and phase angle, measured in a standard laboratory test, were used to construct two master curve models to predict their values at arbitrary temperatures and frequencies. Furthermore, a theoretical model for wave velocity in a linear isotropic viscoelastic material was utilized with measured density, Poisson’s ratio, phase angle and ultrasonic wave velocity to predict the dynamic modulus. Good agreement has been achieved between laboratory measurements and model predictions. It indicates that ultrasonic testing can serve as a rapid method for material property determination
Downregulated miRNA-491-3p accelerates colorectal cancer growth by increasing uMtCK expression
Colorectal carcinoma (CRC) is the second most frequent cancer worldwide. MiR-491-3p, a tumor-suppressive microRNA (miRNA, miR), has been revealed to be abnormally expressed in CRC tissues. Meanwhile, up-regulated ubiquitous mitochondrial creatine kinase (uMtCK) contributes to CRC cell proliferation. Here we aim to explore whether aberrant miR-491-3p expression promotes CRC progression through regulating uMtCK. To this end, miR-491-3p and uMtCK levels were assessed in CRC tissues using quantitative real-time PCR (qRT-PCR). The biological roles of miR-491-3p and uMtCK in regulating CRC growth were evaluated using colony formation assay and mouse Xenograft tumour model. We found that miR-491-3p expression was decreased in CRC tissues compared with matched para-cancerous tissues, whereas uMtCK expression was increased. Functionally, miR-491-3p overexpression repressed SW480 cell growth, whereas miR-491-3p depletion accelerated SW620 cell proliferation and growth. Inversely, uMtCK positively regulated CRC cell proliferation. Mechanistically, miR-491-3p post-transcriptionally downregulated uMtCK expression by binding to 3’-UTR of uMtCK. Consequently, restoring uMtCK expression markedly eliminated the role of miR-491-3p in suppressing CRC growth. Collectively, miR-491-3p functions as a tumour suppressor gene by repressing uMtCK, and may be a potential target for CRC treatment
The effect of 8-OH-DPAT and dapoxetine on gene expression in the brain of male rats during ejaculation
The 5-HT1A receptor agonist 8-hydroxy-2-[di-n-propylamino] tetralin (8-OH-DPAT) promotes ejaculation of male rats, whereas dapoxetine delays this process. However, the gene expression profile of the brain at ejaculation following administrationof these two compounds has not been fully elucidated. In the present study, a transcriptomic BodyMap was generated by conducting mRNA-Seq on brain samples of male Sprague–Dawley rats. The study included four groups: pre-copulatory control (CK) group, ejaculation (EJ) group, 0.5 mg/kg 8-OH-DPAT-ejaculation group (DPAT), and 60 mg/kg dapoxetine-ejaculation (DAP) group. The resulting analysis generated an average of approximately 47 million sequence reads. Significant differences in the gene expression profiles of the aforementioned groups were observed in the EJ (257 genes), DPAT (349 genes) and the DAP (207 genes) compared with the control rats. The results indicate that the expression of Drd1 and Slc6a3 was significantly different after treatment with 8-OH-DPAT, whereas the expression of Drd4 was significantly different after treatment with dapoxetine. Other genes, such as Wnt9b, Cdkn1a and Fosb, exhibited significant differences in expression after the two treatments and are related to bladder cancer, renal cell carcinoma and sexual addiction. The present study reveals the basic pattern of gene expression that was activated at ejaculation in the presence of 8-OH-DPAT or dapoxetine, providing preliminary gene expression information during rat ejaculation
Design of material regulatory mechanism for electrocatalytic converting NO/NO3− to NH3 progress
Abstract Nitric oxide (NO)/nitrate (NO3−) exists as the most hazardous pollutions in the air/water that severely impacts human health. Conventional disposing methods are energy‐consuming and uneconomic. Moreover, ammonia (NH3) fertilizer resources acquire urgent, eco‐friendly, and economical strategies that can remove NO/NO3− pollution and simultaneously convert nitrate species, maintaining nitrogen balance. Electrochemical nitrogen (N) reduction is attracting more attention, particularly electrocatalytic NO/NO3− reduction (ENR) to ammonia supply an approach to fixed nitrogen and generate ammonia. ENR is capable of achieving high NH3 yield and Faradaic efficiency (FE), avoiding competitive hydrogen evolution reactions and easily overcoming strong N≡N triple bond (941 kJ mol−1). There are abundant research studies related to ENR for decreasing hazardous NO/NO3− and supplying profitable NH3. In this review, we discuss different electrocatalytic regulations for crystalline facet engineering, heteroatom doping, heterostructure, surface vacancy engineering, and single‐atom structure, which bring various metal/nonmetal and their combined catalysts to the preferable performance, such as reactivity, selectivity, FE, and stability. Finally, we summarize the challenges and provide the perspectives to promote the industrial application of ENR. Key Points This review focusing on systematically introduce the different modification strategies and regulatory mechanism to enhance the electrochemical performance for NORR/NO3RR, including crystalline facet engineering, heteroatom doping, heterostructure, surface vacancy engineering, and single atom structure
Asymmetric Coordination Environment Engineering of Atomic Catalysts for CO<sub>2</sub> Reduction
Single-atom catalysts (SACs) have emerged as well-known catalysts in renewable energy storage and conversion systems. Several supports have been developed for stabilizing single-atom catalytic sites, e.g., organic-, metal-, and carbonaceous matrices. Noticeably, the metal species and their local atomic coordination environments have a strong influence on the electrocatalytic capabilities of metal atom active centers. In particular, asymmetric atom electrocatalysts exhibit unique properties and an unexpected carbon dioxide reduction reaction (CO2RR) performance different from those of traditional metal-N4 sites. This review summarizes the recent development of asymmetric atom sites for the CO2RR with emphasis on the coordination structure regulation strategies and their effects on CO2RR performance. Ultimately, several scientific possibilities are proffered with the aim of further expanding and deepening the advancement of asymmetric atom electrocatalysts for the CO2RR
Advanced strategies for solid electrolyte interface design with MOF materials
Emerging energy technologies, aimed at addressing the challenges of energy scarcity and environmental pollution, have become a focal point for society. However, these actualities present significant challenges for modern energy storage devices. Lithium metal batteries (LMBs) have gained considerable attention due to their high energy density. Nonetheless, their use of liquid electrolytes raises safety concerns, including dendritic growth, electrode corrosion, and electrolyte decomposition. In light of these challenges, solid-state batteries (SSBs) have emerged as a highly promising next-generation energy storage solution by leveraging lithium metal as the anode to achieve improved safety and energy density. Metal organic frameworks (MOFs), characterized by their porous structure, ordered crystal frame, and customizable configuration, have garnered interest as potential materials for enhancing solid-state electrolytes (SSEs) in SSBs. The integration of MOFs into SSEs offers opportunities to enhance the electrochemical performance and optimize the interface between SSEs and electrodes. This is made possible by leveraging the high porosity, functionalized structures, and abundant open metal sites of MOFs. However, the rational design of high-performance MOF-based SSEs for high-energy Li metal SSBs (LMSSBs) remains a significant challenge. In this comprehensive review, we present an overview of recent advancements in MOF-based SSEs for LMSSBs, focusing on strategies for interface optimization and property enhancement. We categorize these SSEs into two main types: MOF-based quasi-solid-state electrolytes and MOF-based all solid-state electrolytes. Within these categories, various subtypes are identified based on the combination mode, additional materials, formation state, preparation method, and interface optimization measures employed. The review also highlights the existing challenges associated with MOF materials in SSBs applications and proposes potential solutions and future development prospects to guide the advancement of MOFs-based SSEs. By providing a comprehensive assessment of the applications of MOFs in LMSSBs, this review aims to offer valuable insights and guidance for the development of MOF-based SSEs, addressing the key issues faced by these materials in SSBs technology
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