[en] Graphical abstract: The composites prepared with the thermal treatment process of stabilization at 280 °C for 4 h with a heating rate of 2 °C min"−"1 in air followed by carbonization at 800 °C for 14 h with a heating rate of 2 °C min"−"1 in argon exhibit the optimal electrochemical properties. - Highlights: • Binder-free LiFePO_4–CNF composite cathode materials are prepared. • The conductive carbon and LiFePO_4 formation take place simultaneously during thermal treatment. • The reaction behavior of the LiFePO_4 precursors during thermal treatment are investigated. • Different thermal treatment processes would generate different electrochemical performance. • Cycling performance and rate capability are improved with a suitable thermal treatment condition. - Abstract: Binder-free LiFePO_4–carbon nanofiber (LiFePO_4–CNF) composites as lithium-ion battery cathode materials are fabricated by electrospinning and subsequent thermal treatments. The thermal decomposition behavior of the electrospun LiFePO_4 precursor–polyacrylonitrile (LiFePO_4 precursor–PAN) nanofiber composites and the reaction of the LiFePO_4 precursors during thermal treatment are investigated. The effects of thermal treatment parameters such as heating rate, temperature, and duration for stabilization and carbonization on the microstructure, morphology, carbon content, crystal structure of the composites, and electrochemical performance of the resultant half-cell are also studied. When the electrospun LiFePO_4 precursor–PAN nanofiber composites are first stabilized in air at 280 °C for 4 h with a heating rate of 2 °C min"−"1 and then carbonized in argon at 800 °C for 14 h with a heating rate of 2 °C min"−"1, the obtained LiFePO_4–CNF composites exhibit optimal electrochemical properties in terms of a higher initial discharge capacity, more stable charge–discharge cycle behavior, and better rate performance. The initial discharge capacity of the composites is 146.3 mA h g"−"1 at a rate of 0.5 C, while exhibiting a stable cycle performance up to 100 cycles. The results demonstrated that the LiFePO_4–CNF composite cathode materials could be a promising candidate for next-generation lithium-ion batteries and the thermal treatment process is a critical step to prepare LiFePO_4–CNF composites with optimal performances

[en] Uniform hollow superparamagnetic poly(lactic-co-glycolic acid) (PLGA)/Fe_3O_4 composite microspheres composed of an inner cavity, PLGA inner shell and Fe_3O_4 outer shell have been synthesized by a modified oil-in-water (O/W) emulsion-solvent evaporation method using Fe_3O_4 nanoparticles as a particulate emulsifier. The obtained composite microspheres with an average diameter of 2.5 μm showed excellent monodispersity and stability in aqueous medium, strong magnetic responsiveness, high magnetite content (>68%), high saturation magnetization (58 emu g"−"1) and high efficiency in lysozyme adsorption. (paper)

[en] A fiber-optic solution concentration sensor based on a pressure-induced long-period grating (LPG) in a composite optical waveguide is proposed. The composite waveguide consists of a standard single-mode fiber with its coating stripped away, a teflon-cannula and the medium to be measured. An experiment has been carried out to measure the concentration of the sodium chloride (NaCl) solution. The results show that the central resonant wavelengths of the LPG shift towards shorter wavelengths when the concentration of the NaCl solution increases. The central resonant wavelength of the LP₁₄ cladding mode exhibits a total blue shift of 4.13 nm in the NaCl solution concentration range of 0–25%, which corresponds to a sensing sensitivity of 0.17 nm/%

[en] A conformal load-bearing antenna structure (CLAS) combines the antenna into a composite structure such that it can carry the designed load while functioning as an antenna. In this paper, two types of new 3D integrated microstrip antennas (3DIMAs) with different feeding methods are designed to work at the radar L-band. Different from the conventional CLAS, the radiating patch and the ground plane of the 3DIMA are both composed of woven conductive wires and are bonded into the 3D composite physically by Z-yarns, greatly improving the damage tolerance of the antenna. The return loss of the coaxial-fed antenna is −13.15 dB with a resonant frequency of 1.872 GHz, while that of the microstrip-fed antenna is −31.50 dB with a resonant frequency of 1.33 GHz. Both of the 3DIMAs have similar radiation patterns to that of the traditionally designed microstrip antenna. In addition, an experimental investigation of the impact response of the coaxial-fed 3DIMA was carried out and the results showed the radiation pattern had almost no change even when the antenna received an impact energy of 15 J, exhibiting superior impact resistance to that of a conventional microstrip antenna

[en] Accurate three dimensional reconstructions of atomic positions and full quantification of the information contained in atom probe microscopy data rely on understanding the physical processes taking place during field evaporation of atoms from needle-shaped specimens. However, the modeling framework for atom probe microscopy has only limited quantitative justification. Building on the continuum field models previously developed, we introduce a more physical approach with the selection of evaporation events based on density functional theory calculations. This model reproduces key features observed experimentally in terms of sequence of evaporation, evaporation maps, and depth resolution, and provides insights into the physical limit for spatial resolution

[en] This paper provides a comprehensive description of the power generation development in recent years in China, including the increasing trend of installed capacity and generated electricity, the current situation of technology mix and primary energy consumption, and the enlargement of power grid scale. This paper analyses the possible reasons to the nationwide power shortage since 2002, including the accelerating growth of electricity-intensive industries, the increasing of residential electricity consumption due to the rising income level, and the fuel supply shortage. Using of a regressive model, this paper analyses the significant impact of electricity-intensive industries on the electricity demand. Assuming the scenarios of economy development and electricity demand, this paper prospects the power generation development in the future, and describes the development roadmap to achieve the goal proposed by the China's central government

[en] Understanding the relationship between atomic-scale structure and properties is becoming increasingly critical as microstructures are now tailored at the nanometre length scale. Here we demonstrate 3-D mapping of grain orientations through atom probe tomography by utilizing Hough transforms to extract the orientation of crystallographic directions. The disorientation across boundaries is also determined. We are now able to combine the powerful capability of atom probe for measuring the 3-D distribution of atoms with the new ability to provide accurate crystallographic information.

[en] This study is designed to systematically investigate how various factors, such as treatment duration, output power, oxygen gas flux, jet to substrate distance, and moisture regain, influence atmospheric pressure plasma etching rate of polyamide 6 (PA 6) films. The etching rate increased as the output power, oxygen gas flux, and moisture regain increased. As the treatment time increased, the etching rate increased first and then decreased. When the substrate was too close or too far from the nozzle, the etching rate was almost not measurable. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) show an increased surface roughness after the plasma treatment. X-ray photoelectron spectroscopy (XPS) shows a decreased carbon content and an increased oxygen content after the plasma treatment. T-peel strength shows an improved bonding strength between the PA 6 films and an adhesive tape after the plasma treatment.

[en] The microstructural and chemical changes in a Fe–6 at.%Cr binary model alloy neutron irradiated to 1.82 dpa at 290 °C were investigated using atom probe tomography. After irradiation, Si and Cr are found segregated to dislocation loops, which were analyzed in terms of number density, size, and habit plane. Grain boundary chemistry was quantitatively compared between the as-received and the neutron irradiated alloys. The results are discussed in the context of equilibrium segregation, radiation-enhanced diffusion, and/or radiation induced segregation

[en] Highlights: • MXene is firstly added into PDMS to improve the electronegativity and conductivity. • A facile and effective method for porous PDMS/MXene film was developed. • Laser-induced technology is firstly introduced into electrode fabrication for TENG. • The TENG realizes an effective harvesting of leaf swing and human writing energy. • The TENG is used as a self-driven sensor array to recognize a real-time trajectory. -- Abstract: The ambient dissipated energy such as the vast scale of mechanical energy in the agricultural system (e.g., leaf swing energy) and the writing motion existing extensively in our daily life are underutilized. Herein, to address these issues and overcome the limitations of conventional batteries, we fabricated a highly flexible and effective triboelectric nanogenerator (TENG) based on MXene and polydimethylsiloxane (PDMS) composite (PDMS/MXene) film and laser-induced graphene (LIG) electrode. The introduction of conductive and electronegative MXene into PDMS to fabricate porous film, not only enhances the electrical conductivity but also increases the triboelectronegativity. As a result, the output performance is significantly improved, 7-fold greater than the pure flat PDMS-based TENG. The developed TENG with excellent performance, considerable adhesion, and outstanding flexibility was successfully applied for harvesting leaf swing energy and being used as a writing board to collect writing energy. Furthermore, we developed a MXene-based TENG array acting as a self-powered sensor for handwriting recognition. In this regard, MXene-enabled TENG possesses a great promising in harvesting mechanical energy from the agricultural field (e.g., leaf swing energy) and human activities (e.g., writing), moreover, it can further be applied in writing or tactile sensing for pad, robotics, and man-machine interaction field.