In summary, these contributions present the current interdisciplinary researches from different aspects. We would like to sincerely thank all the coauthors who have made important contributions to this Special Issue. We also thank the professional editorial office of Journal of Central South University for their hard-works to make this issue such a great success.

Gold nanoparticles (GNPs) have been extensively used in nanomedicine and neuroscience owing to their biological inertness, peculiar opto-electronic and physico-chemical features. However, the effect of GNPs shape on the neurophysiological properties of single neuron is still unclear. To tackle this issue, different shape GNPs (nanosphere, nanotriakisoctahedron and nanoflower) were synthesized to investigate the effect of GNPs on the voltage-dependent sodium channel and the action potential (AP) of hippocampal CA1 neurons in mice. The results indicated that GNPs inhibited the amplitudes of voltage-gated sodium current (I_Na) and led to a hyperpolarizing shift in the voltage-dependence curve of both activation and inactivation of I_Na. GNPs also increased neuronal excitability and altered some properties of AP. Moreover, most alterations in AP properties were observed in nanoflower GNPs treated CA1 neurons, suggesting that the neurotoxicity of gold nanoparticles is surface roughness-dependent. These results may provide a valuable direction in the clinical application of GNPs.

Excessive discharge of dye wastewater has brought serious harm to human health and the environment. In this paper, a magnetic absorbent, ferroferric oxide@β-cyclodextrin (Fe₃O₄@CD), was prepared for the efficient adsorption removal of basic fuchsin (BF) from dye wastewater, based on the special amphiphilicity of β-CD and the strong magnetism of Fe₃O₄. A series of influence factors including the initial dye concentration, adsorbent dosage, temperature and pH were investigated, as well as the adsorption mechanism. The results show that Fe₃O₄@CD has the best adsorption and removal effect on BF dye at room temperature and neutral pH, when the initial concentration of dye is 25 mg/L and the adsorbent dosage is 100 mg. The adsorption behavior conforms to the pseudo-second-order kinetics and the Langmuir adsorption isotherm, and the adsorption process is spontaneously endothermic. Fe₃O₄@CD adsorbed with BF dye can be rapidly separated under an external magnetic field and then easily regenerated by HCl treatment. After 5 times of recycling, the removal rate of the prepared magnetic composite on BF dye is kept above 75%. This work will provide an economic and eco-friendly technology for the treatment of the actual dye wastewater.

Lithium-sulfur (Li-S) batteries have attracted enormous interest due to their super-high theoretical energy density (2600 W · h/kg) in recent years. However, issues such as lithium dendrites and the shuttle effect severely hampered the large-scale application of Li-S batteries. Herein, a novel bifunctional gel polymer electrolyte, poly(N,N-diallyl-N, N-dimethylammonium bis(trifluoromethylsulfonylimide))-P(VDF-HFP) (PDDA-TFSI-P(VDF-HFP), PTP), was prepared by anion exchange reaction to tackle the above problems. Benefited from the interaction between TFSI⁻ and quaternary ammonium ion in PTP, a higher lithium-ion transference number was obtained, which could availably protect Li metal anodes. Meanwhile, due to the adsorption interactions between PDDA-TFSI and polysulfides (LiPSs), the shuttle effect of Li-S batteries could be alleviated effectively. Consequently, the Li symmetric batteries assembled with PTP cycled more than 1000 h and lithium metal anodes were protected effectively. Li-S batteries assembled with this polymer electrolyte show a discharge specific capacity of 813 mA·h/g after 200 cycles and 467 mA·h/g at 3C, exhibiting excellent cycling stability and C-rates performance.

In the modern society, there is a strong demand for semiconductor chips, and the 4H polytype silicon carbide (4H-SiC) power device is a promising candidate for the next generation semiconductor chip, which can be used in various power electronic systems. In order to improve the performance of the 4H-SiC power device, a novel ultrahigh-voltage (UHV) 4H-SiC merged p-type/intrinsic/n-type (PiN) Schottky (MPS) diode with three-dimensional (3D) p-type buried layers (PBL) (3D-PBL MPS) is proposed and investigated by numerical simulation. The static forward conduction characteristics of the 3D-PBL MPS are similar to those of the conventional 4H-SiC MPS diode without the PBL (PBL-free MPS). However, when the 3D-PBL MPS is in the reverse blocking state, the 3D PBL can transfer the peak electric field (E_peak) into a deeper position in the body of the epitaxial layer, and enhance the ability of the device to shield the high electric field at the Schottky contact interface (E_S), so that the reverse leakage current of the 3D-PBL MPS at 10 kV is only 0.002% of that of the PBL-free MPS. Meanwhile, the novel 3D-PBL MPS has overcome the disadvantage in the 4H-SiC MPS diode with the two-dimensional PBL (2D-PBL MPS), and the forward conduction characteristic of the 3D-PBL MPS will not get degenerated after the device converts from the reverse blocking state to the forward conduction state because of the special depletion layer variation mechanism depending on the 3D PBL. All the simulation results show that the novel UHV 3D-PBL MPS has excellent device performance.

Alumina ceramics are widely used in many fields such as cutting tools, laser shock materials, roadbed board and refractory. Herein, Al₂O₃ ceramics are prepared by a low-cost pressureless sintering technology, using the binary sintering aids of MgO and SiO₂. The effects of sintering temperature and the ratio of binary sintering aids on the mechanical properties and microstructure of Al₂O₃ ceramics are investigated. A spinel second phase (MgAl₂O₄) is found out by the analysis of the results of XRD and EDS when MgO and SiO₂ are introduced in the samples. The optimum properties are found when MgO content is 20 wt% based on the total sintering aids and the sintering temperature is 1550 °C. The bending strength and the bulk density reach a maximum value of 314 MPa and 3.73 g/cm³, respectively. The addition of appropriate amount of SiO₂ makes the formation of liquid phase sintering and the removal of large pores. Meanwhile, a small amount of magnesium oxide doping has an effect on the grain refinement from the microstructure of the sample. Therefore, it is believed that MgO and SiO₂ are the ideal sintering aids for promoting the densification and property of alumina ceramics.

A series of shape-persistent polyphenylene dendritic C₆₀ derivatives as the electron transport materials were designed and synthesized via a catalyst-free Diels-Alder [4+2] cycloaddition reaction. These increasing hyperbranched scaffolds could effectively enhance the solubility; notably, both first and second generation dendrimers, C₆₀-G1 and C₆₀-G2, demonstrated more than 5 times higher solubilities than pristine C₆₀. Furthermore, both simulated and experimental data proved their promising solution-processabilities as electron-transporting layers (ETLs) for perovskite solar cells. As a result, the planar p-i-n structural perovskite solar cell could achieve a maximum power conversion efficiency of 14.7 % with C₆₀-G2.

Transition metal dichalcogenides are interesting candidates as photocatalysts for hydrogen evolution reaction. The MnPSe₃/WS₂ heterostructure is hence studied here with first principles calculations by exploring its electronic properties under the application of an electric field. It is discovered that the band gap will decrease from the WS₂ monolayer to the MnPSe₃/WS₂ heterostructure with Perdew-Burke-Ernzerhof functional, while increase slightly when electron correlation is involved. The conduction band minimum of the heterostructure is determined by the MnPSe₃ layer, while the valence band maximum is contributed by the WS₂ layer. The band edges and band gap suggest that the heterostructure will have good photocatalytic properties for water splitting. Moreover, comparing to monolayer WS₂, the light absorption in both the ultraviolet and visible regions will be enhanced. When an electric field is present, a linear relation is observed between the electric field and the band gap within specific range, which can thus modulate the photocatalytic performance of this heterostructure.

Compared to conventional quantum dot light-emitting diodes, tandem quantum dot light-emitting diodes (TQLEDs) possess higher device efficiency and more applications in the field of flat panel display and solid-state lighting in the future. The TQLED is a multilayer structure device which connects two or more light-emitting units by using an interconnection layer (ICL), which plays an extremely important role in the TQLED. Therefore, realizing an effective ICL is the key to obtain high-efficiency TQLEDs. In this work, the p-type materials polys (3, 4-ethylenedioxythiophene), poly (styrenesulfonate) (PEDOT: PSS) and the n-type material zinc magnesium oxide (ZnMgO), were used, and an effective hybrid ICL, the PEDOT: PSS-GO/ZnMgO, was obtained by doping graphene oxide (GO) into PEDOT:PSS. The effect of GO additive on the ICL was systematically investigated. It exhibits that the GO additive brought the fine charge carrier generation and injection capacity simultaneously. Thus, the all solution-processed red TQLEDs were prepared and characterized for the first time. The maximum luminance of 40877 cd/m² and the highest current efficiency of 19.6 cd/A were achieved, respectively, showing a 21% growth and a 51% increase when compared with those of the reference device without GO. The encouraging results suggest that our investigation paves the way for efficient all solution-processed TQLEDs.

Piezoelectric ceramic based high-temperature acoustic emission (AE) sensor is required urgently in the structural health monitoring of high-temperature fields. In this research, a series of 0.45(BiSc_xO₃-BiFe_1−xO₃)-0.48PbTiO₃-0.07BaTiO₃ (BSc_xFe_1−x-PT-BT, n(Sc)/n(Fe) =0.4/0.6 − 0.6/0.4) ceramics with both high Curie temperature and large piezoelectric constant were presented. The structure and electrical properties of BSc_xFe_1−x-PT-BT ceramics as a function of n(Sc)/n(Fe) have been systematically investigated. All the ceramics possess a perovskite structure, and the phase approaches from the rhombohedral toward the tetragonal phase with the decrease of n(Sc)/n(Fe). The BSc_0.5Fe_0.5-PT-BT and BSc_0.55Fe_0.45-PT-BT piezoelectric ceramics exhibit good piezoelectricity (d₃₃=250−281 pC/N), high Curie temperature (T_C=430−450 °C) and excellent temperature stability. These improvements are greatly attributed to the balance between rhombohedral and tetragonal phase near morphotropic phase boundary with dense microstructure of ceramics. AE sensor based BSc_0.5Fe_0.5-PT-BT piezoelectric ceramic was designed, prepared and tested. The high-temperature stability of AE sensor was characterized through pencil-lead breaking with in situ high-temperature test. The noise of AE sensor is less than 40 dB, and the acoustic signal is up to 90 dB at 200 °C. As a result, AE sensors based on BSc_xFe_1−x-PT-BT piezoelectric ceramics are expected to be applied into the structural health monitoring of high temperature fields.

Variable stiffness composite laminates (VSCLs) are promising in aerospace engineering due to their designable material properties through changing fiber angles and stacking sequences. Aiming to control the thermal postbuckling and nonlinear panel flutter motions of VSCLs, a full-order numerical model is developed based on the linear quadratic regulator (LQR) algorithm in control theory, the classical laminate plate theory (CLPT) considering von Kármán geometrical nonlinearity, and the first-order Piston theory. The critical buckling temperature and the critical aerodynamic pressure of VSCLs are parametrically investigated. The location and shape of piezoelectric actuators for optimal control of the dynamic responses of VSCLs are determined through comparing the norms of feedback control gain (NFCG). Numerical simulations show that the temperature field has a great effect on aeroelastic tailoring of VSCLs; the curvilinear fiber path of VSCLs can significantly affect the optimal location and shape of piezoelectric actuator for flutter suppression; the unstable panel flutter and the thermal postbuckling deflection can be suppressed effectively through optimal design of piezoelectric patches.

A catalyst of ferroelectric-BaTiO₃@photoelectric-TiO₂ nanohybrids (BaTiO₃@TiO₂) with enhanced photocatalytic activity was synthesized via a hydrolysis precipitation combined with a hydrothermal approach. Compared to pure TiO₂, pure BaTiO₃ and BaTiO₃/TiO₂ physical mixture, the heterostructured BaTiO₃@TiO₂ exhibits significantly improved photocatalytic activity and cycling stability in decomposing Rhodamine B (RhB) and the degradation efficiency is 1.7 times higher than pure TiO₂ and 7.2 times higher than pure BaTiO₃. These results are mainly attributed to the synergy effect of photoelectric TiO₂, ferroelectric-BaTiO₃ and the rationally designed interfacial structure. The mesoporous microstructure of TiO₂ is of a high specific area and enables excellent photocatalytic activity. The ferroelectric polarization induced built-in electric field in BaTiO₃ nanoparticles, and the intimate interfacial interactions at the interface of BaTiO₃ and TiO₂ are effective in driving the separation and transport of photogenerated charge carriers. This strategy will stimulate the design of heterostructured photocatalysts with outstanding photocatalytic performance via interface engineering.

To meet the requirements of high performance, low cost, and easy operation of the robot, a brushless motor drive and control system for the robot joint is designed, including CAN bus, WPF upper host computer development, and magnetic encoders, and other sensors, in which the STM32F103 chip is used as the main control chip, and the DRV8323 is a brushless motor drive chip. The principle of field-oriented control (FOC) brushless motor drive is elaborated. Meanwhile, the drive and control system design is completed from both hardware and software aspects. Finally, the PID algorithm is used for the closed-loop speed test of the robot joint. The experimental result shows that the designed robot joints and control system run smoothly and reliably, have the characteristics of modularization and miniaturization, and are suitable for the control of micro-service robots and manipulators.

As one of the most common medical diagnosis methods, urinalysis is a highly demanded technique for screening tests or daily monitoring of various diseases. With the rapid development of POC (point-of-care) systems, a convenient house-using urinalysis device is widely needed. However, considering the difference of onboard systems and multiple test indicators in urinalysis, the design of such an intelligent device is still challenging. In this paper, a smartphone-based portable urinalysis system has been developed and applied for the colorimetric analysis of routine urine examination indices using an Android app. By integrating the test paper sensor in the portable device for urinalysis, our system significantly improves the instability of conventional dipstick-based manual colorimetry, and the smartphone application used for color discrimination enhances the accuracy of the visual assessment of sample strips. Using a simple operation approach that takes ∼ 2 min per test, our system can be applied as rapid urinalysis for routine check-ups.

Fault degradation prognostic, which estimates the time before a failure occurs and process breakdowns, has been recognized as a key component in maintenance strategies nowadays. Fault degradation processes are, in general, slowly varying and can be modeled by autoregressive models. However, industrial processes always show typical nonstationary nature, which may bring two challenges: how to capture fault degradation information and how to model nonstationary processes. To address the critical issues, a novel fault degradation modeling and online fault prognostic strategy is developed in this paper. First, a fault degradation-oriented slow feature analysis (FDSFA) algorithm is proposed to extract fault degradation directions along which candidate fault degradation features are extracted. The trend ability assessment is then applied to select major fault degradation features. Second, a key fault degradation factor (KFDF) is calculated to characterize the fault degradation tendency by combining major fault degradation features and their stability weighting factors. After that, a time-varying regression model with temporal smoothness regularization is established considering nonstationary characteristics. On the basis of updating strategy, an online fault prognostic model is further developed by analyzing and modeling the prediction errors. The performance of the proposed method is illustrated with a real industrial process.

Phosphorus is an essential element in agricultural production and chemical industry. However, since the risk of casualties and economic loss by mining accidents, the application of clean and safe production in phosphorus mines encounters great challenges. For this purpose, a man-machine-environment system composed of evaluation indexes was established, and the grading standards of indexes were defined. Firstly, the measurements of 39 qualitative indexes were obtained through the survey data. According to the measured values of 31 quantitative indexes, the measurements of quantitative indexes were calculated by linear measurement function (LM) and other three functions. Then the singleindex measurement evaluation matrixes were established. Secondly, the entropy weight method was used to determine the weights of each index directly. The analytic hierarchy process (AHP) was also applied to calculate the weights of index and index factor hierarchies after the established hierarchical model. The weights of system hierarchies were given by the grid-based fuzzy Borda method (GFB). The comprehensive weights were determined by the combination method of AHP and GFB (CAG). Furthermore, the multi-index comprehensive measurement evaluation vectors were obtained. Thirdly, the vectors were evaluated by the credible degree recognition (CDR) and the maximum membership (TMM) criteria. Based on the above functions, methods, and criteria, 16 combination evaluation methods were recommended. Finally, the clean and safe production grade of Kaiyang phosphate mine in China was evaluated. The results show that the LM-CAG-CDR is the most reasonable method, which can not only determine the clean and safe production grade of phosphorus mines, but also improve the development level of clean and safe mining of phosphorus mines for guidance. In addition, some beneficial suggestions and measures were also proposed to advance the clean and safe production grade of Kaiyang phosphorus mine.

Long-time driving and monotonous visual environment increase the safety risk of driving in an extra-long tunnel. Driving fatigue can be effectively relieved by setting the visual fatigue relief zone in the tunnel. However, the setting form of visual fatigue relief zone, such as its length and location, is difficult to be designed and quantified. By integrating virtual reality (VR) apparatus with wearable electroencephalogram (EEG) -based devices, a hybrid method was proposed in this study to assist analyzers to formulate the layout of visual fatigue relief zone in the extra-long tunnel. The virtual environment of this study was based on an 11.5 km extra-long tunnel located in Yunnan Province in China. The results indicated that the use of natural landscape decoration inside the tunnel could improve driving fatigue with the growth rate of attention of the driver increased by more than 20%. The accumulation of driving fatigue had a negative effect on the fatigue relief. The results demonstrated that the optimal location of the fatigue relief zone was at the place where driving fatigue had just occurred rather than at the place where a certain amount of driving fatigue had accumulated.

The preparation of superhydrophobic or underwater superoleophobic interface materials has become a research hotspot because of their wide application in self-cleaning, drag reduction, oil-water separation, anti-oil pollution and so on. The unique wettability of organisms gives inspiration to design and create new interface materials. This review focuses on the recent research progress of femtosecond laser micro/nano fabrication for bioinspired superhydrophobic or underwater superoleophobic surfaces. This review starts with a presentation of the related background including the advantages of femtosecond laser and wettability theoretical basis. Then, organisms with unique wettability in nature, the preparation of superhydrophobic or underwater superoleophobic surfaces by femtosecond lasers on different materials, and their related important applications are introduced. Finally, the current challenges and future prospects with regard to this field are provided.

Triboluminescence, also as known as mechanoluminescence, is an attractive optical behavior that means the light emitted from specific organic and inorganic materials when they are subjected to external forces, such as crushing, deformation, cleaving, vibration. Inorganic triboluminescent materials show great potential for applications in sensing, such as stress sensing, damage detection. However, the triboluminescent mechanism of organic materials should be pushed further as well as their application. In this review, we summarized the history of development and possible mechanism of organic triboluminescent materials, and discussed various applications in sensing field. At the same time, inspired by the existing research progress in inorganic triboluminescent materials, we proposed the flourishing development prospects of organic triboluminescent materials in stress sensors, movement monitoring, imaging stress distribution, visualization of crack propagation, structural diagnosis, and other fields.

MXenes are emerging two-dimensional (2D) nanomaterials composed of transition metal carbides and/or nitrides and possess unique layered structures with abundant surface functional groups, which enable them with excellent and tunable properties. MXenes films can be solution-processed in polar solvents and are very suitable for optoelectronic device applications. Especially, Ti₃C₂T_x MXene with the clear advantages of facile synthesis, flexible surface controlling, easily tunable work function, high optical transmittance and excellent conductivity shows great potential for applications in organic/perovskite optoelectronic devices. Therefore, this review briefly introduces the mainstream synthesis methods, optical and electrical properties of MXenes, and comprehensively summarizes the versatile applications of Ti₃C₂T_x MXene in different functional layers (electrode, interface layer and active layer) of organic/perovskite optoelectronic devices including solar cells and light-emitting diodes. Finally, the current application characteristics and the future possibilities of MXenes in organic/perovskite optoelectronic devices are concluded and discussed.