Xi'an Jiaotong University

About: Xi'an Jiaotong University is a education organization based out in Xi'an, China. It is known for research contribution in the topics: Heat transfer & Dielectric. The organization has 85440 authors who have published 99682 publications receiving 1579683 citations. The organization is also known as: '''Xi'an Jiaotong University''' & Xi'an Jiao Tong University.

Potassium-ion batteries: outlook on present and future technologies

Abstract: The limited resources and uneven distribution of lithium stimulate strong motivation to develop new rechargeable batteries that use alternative charge carriers. Potassium-ion batteries (PIBs) are at the top of the list of alternatives because of the abundant raw materials and relatively high energy density, fast ion transport kinetics in the electrolyte, and low cost. However, several challenges still hinder the development of PIBs, such as low reversible capacity, poor rate performance, and inferior cycling stability. Research on the cathode is currently focused on developing materials with high energy density and cycling stability, mainly including layered transition metal oxides, polyanion compounds, organic compounds, etc. Anodes based on intercalation reactions, conversion reactions, and alloying with potassium are currently under development, and promising results have been published. This review comprehensively summarizes the research effort to date on the electrode material optimization (e.g., crystals, morphology, reaction mechanisms, and interface control), the synthesis methods, and the full cell fabrication for PIBs to enhance the electrochemical potassium storage and provide a platform for further development in this battery system.

Texturation boosts the thermoelectric performance of BiCuSeO oxyselenides

Abstract: We present a high ZT ∼ 1.4 in textured Bi0.875Ba0.125CuSeO obtained by a hot-forging process. The carrier mobility along the direction perpendicular to the pressing direction was significantly increased, resulting in increase in the electrical conductivity and maximization of the power factor at 923 K from 6.3 μW cm−1 K−2 for the sample before hot-forging to 8.1 μW cm−1 K−2 after the hot-forging process. Therefore, the maximum ZT was significantly increased from ∼1.1 to 1.4 through texturing for Bi0.875Ba0.125CuSeO, which is the highest ZT ever reported among oxygen containing materials.

Gold Mesostructures with Tailored Surface Topography and Their Self-Assembly Arrays for Surface-Enhanced Raman Spectroscopy

Abstract: We report a facile particle mediated aggregation protocol to synthesize "sea urchin"-like gold mesoparticles with tailored surface topography via a secondary nucleation and growth process. Surprisingly, these multitip Au mesoparticles are capable of self-assembling into monolayer or multiple layer arrays on Si substrates with a convincing reproducibility and homogeneity over large areas. Raman measurements show that these individual sea urchin-like multitipped gold mesoparticles exhibit a high enhancement of surface-enhanced Raman scattering (SERS). In addition, the sea urchin-like mesoparticle arrays display a further enhancement of SERS by 1 or 2 orders of magnitude over the individual mesoparticle due to the formation of additional hot spots between the particles. The current protocol stands out as a potentially interesting approach for the fabrication of technologically important SERS-based sensors.

Circles reshaping the RNA world: from waste to treasure.

Abstract: A new type of RNAs was identified from genes traditionally thought to express messenger or linear ncRNA (noncoding RNA) only. They were subsequently named as circRNAs (circular RNAs) due to the covalently closed structure. Accumulating studies were performed to explore the expression profile of circRNAs in different cell types and diseases, the outcomes totally changed our view of ncRNAs, which was thought to be junk by-products in the process of gene transcription, and enriched our poor understanding of its underlying functions. The expression profile of circRNAs is tissue-specific and alters across various stages of cell differentiation. The biological function of circRNAs is multi-faceted, involving five main features (sponge effect, post-transcriptional regulation, rolling circle translation, circRNA-derived pseudogenes and splicing interference) and varying differently from the locations, binding sites and acting modes of circRNAs. The regulating role of circRNAs is not isolated but through an enormous complicated network involving mRNAs, miRNAs and proteins. Although most of the potential functions still remain unclear, circRNAs have been proved to be ubiquitous and critical in regulating cellular processes and diseases, especially in cancers, from the laboratory to the clinic. Herein, we review circRNAs’ classification, biogenesis and metabolism, their well-studied and anticipated functions, the current understanding of the potential implications of circRNAs in tumorigenesis and cancer targeted therapy.

Fabrication and Dielectric Characterization of Advanced BaTiO3/Polyimide Nanocomposite Films with High Thermal Stability

Abstract: Barium titanate/polyimide (BaTiO3/PI) nanocomposite films with high dielectric permittivity (20), high breakdown strength (67 MV m−1), and high thermal stability are prepared by an in-situ polymerization process. A very thin polymer layer (about 5 nm) is coated on the surface of nanosized BaTiO3 particles to form a core–shell-like structure, which can guarantee homogeneous dispersion of the BaTiO3 particles in the PI matrix. It is confirmed that the core–shell-like structure originates from both the electrostatic attraction between the precursor poly(amic acid) (PAA) and the BaTiO3 particles and the hydrogen bond interaction between PI and the BaTiO3 particles. Such a structure also has some influence on the dielectric properties and breakdown strength of films. After casting and degassing of the sticky film, the dielectric permittivity of the nanocomposite film is close to or even higher than that of submicrocomposite films, which is attributed to the advanced interfacial structure between the BaTiO3 and PI phases.