A Genetic Algorithm for Simultaneous Determination of Thin Films Thermal Transport Properties and Contact Resistance

A genetic algorithm （GA） was studied to simultaneously determine the thermal transport properties and the contact resistance of thin films deposited on a thick substrate. A pulsed photothermal reflectance （PPR） system was employed for the measurements. The GA was used to extract the thermal properties. Measurements were performed on SiO2 thin films of different thicknesses on silicon substrate. The results show that the GA accompanied with the PPR system is useful for the simultaneous determination of thermal properties of thin films on a substrate.

Research on the Anti-corona Coating of the Power Transmission Line Conductor

An anti-corona method for the power transmission lines is proposed in this paper. The RTV coating is used as the anti-corona coating, which is spaying onto the surface of the wearing conductor. The corona characteristic of the conductor test was done, and the corona onset voltage increase after the spraying of the anti-corona layer, the corona loss in the same voltage decrease, which could prove the excellent effect of improving the corona characteristic of the conductor. This anti-corona method will have great prospect, based on the background of the construction of UHV power transmission lines.

Anomaly Detection and Pattern Differentiation in Monitoring Data from Power Transformers

Aiming at the problem of abnormal data generated by a power transformer on-line monitoring system due to the influences of transformer operation state change,external environmental interference,communication interruption,and other factors,a method of anomaly recognition and differentiation for monitoring data was proposed.Firstly,the empirical wavelet transform(EWT)and the autoregressive integrated moving average(ARIMA)model were used for time series modelling of monitoring data to obtain the residual sequence reflecting the anomaly monitoring data value,and then the isolation forest algorithm was used to identify the abnormal information,and the monitoring sequence was segmented according to the recognition results.Secondly,the segmented sequence was symbolised by the improved multi-dimensional SAX vector representation method,and the assessment of the anomaly pattern was made by calculating the similarity score of the adjacent symbol vectors,and the monitoring sequence correlation was further used to verify the assessment.Finally,the case study result shows that the proposed method can reliably recognise abnormal data and accurately distinguish between invalid and valid anomaly patterns.

任意边界条件下功能梯度阶梯圆柱壳的振动特性研究

对金属-陶瓷功能梯度材料阶梯圆柱壳在任意边界条件下的振动特性展开了研究.首先,采用Voigt模型和幂函数体积分数得到金属-陶瓷功能梯度材料属性.其次,引入人工弹簧技术,模拟各壳段间的连续耦合及壳体两端的边界条件,并基于一阶剪切变形理论推导出壳体的能量表达式.最后,选取Chebyshev多项式构造容许函数,基于Rayleigh-Ritz法对任意边界条件下壳体的动力学微分方程进行求解计算,通过与现有文献对比,验证了本文方法的有效性与收敛性.结果表明:体积分数指数增长,壳体固有频率也随之增长;而长径比和厚径比对壳体的振动特性影响均不同,随着长径比的增加壳体的固有频率减小,随着厚径比的增加壳体的固有频率增大;且相较于旋转弹簧,平动弹簧的刚度值对壳体振动特性的影响显著.

Improving the band alignment at PtSe_(2)grain boundaries with selective adsorption of TCNQ

Grain boundaries in two-dimensional(2D)semiconductors generally induce distorted band alignment and interfacial charge,which impair their electronic properties for device applications.Here,we report the improvement of band alignment at the grain boundaries of PtSe_(2),a 2D semiconductor,with selective adsorption of a presentative organic acceptor,tetracyanoquinodimethane(TCNQ).TCNQ molecules show selective adsorption at the PtSe_(2)grain boundary with strong interfacial charge.The adsorption of TCNQ distinctly improves the band alignment at the PtSe_(2)grain boundaries.With the charge transfer between the grain boundary and TCNQ,the local charge is inhibited,and the band bending at the grain boundary is suppressed,as revealed by the scanning tunneling microscopy and spectroscopy(STM/S)results.Our finding provides an effective method for the advancement of the band alignment at the grain boundary by functional molecules,improving the electronic properties of 2D semiconductors for their future applications.

Co-doping strategy enhanced the ionic conductivity and excellent lithium stability of garnet-type Li_(7)La_(3)Zr_(2)O_(12)electrolyte in all solidstate lithium batteries

Garnet-type Li_(7)La_(3)Zr_(2)O_(12)(LLZO)is one of the most promising solid-state electrolytes(SSEs).However,the application of LLZO is limited by structural instability,low ionic conductivity,and poor lithium stability.To obtain a garnet-type solid electrolyte with a stable structure and high ionic conductivity,a series of TaeCe co-doping cubic Li_(6.4)La_(3)Zr_(1.4-x)Ta_(0.6)Ce_(x)O_(12)(LLZTCO,x=,0.02,0.04,0.06,0.08,0.10,0.20,0.30)electrolytes were successfully synthesized through conventional solid-phase method.The Ta^(5+)doping can introduce more lithium vacancies and effectively maintain the stability of the cubic phase.The Ce^(4+)with a larger ionic radius is introduced into the lattice to widen the Lit migration bottleneck size,which significantly increased the ionic conductivity to 1.05×10^(-3)S/cm.It also shows excellent stability to lithium metal by the optimization of Lit transport channel.Li||LLZTCO||Li symmetric cells can cycle stably for more than 6000 h at a current density of 0.1 mA/cm^(2)without any surface modifications.The commercialization potential of LLZTCO samples in all solid-state lithium batteries(ASSLBs)is confirmed by the prepared LiFePO_(4)||LLZTCO||Li cells with a capacity retention rate of 98%after 100 cycles at 0.5C.This new co-doping method presents a practical solution for the realization of high-performance ASSLBs.

The Behavior of Carbonized Polymer Dots at the Nano-Bio Interface and Their Luminescent Mechanism:A Physical Chemistry Perspective

Carbonized polymer dots(CPDs)have been widely applied in biomedical fields,such as imaging,diagnosis and drug delivery.Since the complex,non-equilibrated and dynamic nature of biological systems inevitably affect the predesigned properties of CPDs,then efficiency and ultimate outcome of CPDs in biological identity will be transformed by the ubiquitous nano-bio interactions.Herein,our recent progress about elucidating the behavior of CPDs at nano-bio interface from the perspective of physical chemistry has been summarized in the review,mainly at the bio-macromolecular,cellular membrane and cellular levels,which is crucial for characterize their relative cytotoxicity and clinical transformation.Moreover,we mainly focused on the quantitative relationship of nano-bio interactions between CPDs with biological identity and related thermodynamics parameters during this process is also obtained from advanced isothermal titration calorimetry technique.Finally,our recent study about the photoluminescence origin is also included in this review,which favors modulating the photoluminescence of CPDs.

Dual-stimuli responsive near-infrared emissive carbon dots/hollow mesoporous silica-based integrated theranostics platform for real-time visualized drug delivery

Due to better penetrating abilities of near-infrared (NIR) light and lower autofluorescence of biological tissue at NIR region, the combination of NIR fluorescent imaging with therapeutic abilities has gradually emerged as a promising strategy for cancer therapy. Herein, tumor microenvironment (TME) sensitive nanocarriers based on doxorubicin hydrochloride (DOX), NIR emitting carbon dots (C-dots), hollow mesoporous silica nanoparticles (HMSN) and anionic polymer citraconic anhydride-modified polylysine (PLL(cit)) are fabricated for imaging guided drug delivery. The NIR emitting C-dots were conjugated onto the surface of HMSN via disulfide bonds which can be reduced by intracellular glutathione (GSH) and result in the release of DOX into cells. And then the PLL(cit) was grafted on the surface of the nanocarriers to endow the nanocarriers with charge convertible property in mildly acidic TME (pH = 6.50) which results in prolonged blood circulation time and enhanced cellular internalization. The in vitro and in vivo experiments confirmed that the dual pH/GSH responsive features of nanocarriers can eliminate the tumor tissues effectively and elicit much slighter side effects. Moreover, since the fluorescence of C-dots can be recovered after the reduction of disulfide bonds and selectively accumulation of nanocarriers around tumor tissue, the DOX@HMSN-SS-C-dots-PLL(cit) can be served as a promising NIR fluorescence probe for targeted imaging of tumor tissue. As a kind of multifunctional nanocarrier with NIR fluorescent imaging and therapeutic functions, the theranostic nanocarriers hold great potential for tumor therapy and in vivo imaging of tumor tissue.

Line defects in monolayer TiSe_(2) with adsorption of Pt atoms potentially enable excellent catalytic activity

Two-dimensional(2D)materials with defects are desired for catalysis after the adsorption of monodispersed noble metal atoms.High-performance catalysts with the absolute value of Gibbs free energy(|△GH|)close to zero,is one of the ultimate goals in the catalytic field.Here,we report the formation of monolayer titanium selenide(TiSe2)with line defects.The low-temperature scanning tunneling microscopy/spectroscopy(STM/S)measurements revealed the structure and electronic states of the line defect.Density functional theory(DFT)calculation results confirmed that the line defects were induced by selenium vacancies and the STM simulation was in good agreement with the experimental results.Further,DFT calculations show that monolayer TiSe_(2) with line defects have good catalytic activity for hydrogen evolution reaction(HER).If the defects are decorated with single Pt atom,the HER catalytic activity will be enhanced dramatically(|△GH|=0.006 eV),which is much better than Pt metal(|△GH|=0.09 eV).Line defects in monolayer TiSe_(2)/Au(111)provide a wonderful platform for the design of high-performance catalysts.

Na-K liquid alloy:A review on wettability enhancement and ionic carrier selection mechanism

The intrinsic liquid interface of Na-K alloy allays concerns about dendrite growth on metal anodes that are thermodynamically within the room temperature(20-22℃).Nevertheless,it hinders the formation of a stable electrode structure due to the inferior wettability induced by considerable liquid tension.In addition,the dominant ionic carrier in the Na-K alloy is subject to multiple factors,which is not conducive to customized battery design.This review,based on recently reported frontier achievements on Na-K liquid anodes,summarizes practical strategies for promoting the wettability by hightemperature induction,capillary effect,vacuum infiltration,and solid interface protection.Furthermo re,four selection mechanisms of the dominant ionic carrier are presented:(1)ion property dominated,(2)cathode dominated,(3)separator dominated,and(4)solid electrolyte interface dominated.Notably,initial electrolytes in energy storage systems have been unable to play a decisive role in ionic selection.Utilizing a superior wettability strategy and simultaneously identifying the dominant ionic carrier can facilitate the tailored application of dendrite-free Na-K liquid anodes.

Erratum to: Dual-stimuli responsive near-infrared emissive carbon dots/hollow mesoporous silica-based integrated theranostics platform for real-time visualized drug delivery

Erratum to Nano Research 2021,14(11):4264-4273 https://doi.org/10.1007/s12274-021-3624-4 The first two authors part of this article was unfortunately misrepresented on the first page and in the ESM.