Hetero‐Nanonet Rechargeable Paper Batteries: Toward Ultrahigh Energy Density and Origami Foldability

Forthcoming smart energy era is in strong pursuit of full‐fledged rechargeable power sources with reliable electrochemical performances and shape versatility. Here, as a naturally abundant/environmentally friendly cellulose‐mediated cell architecture strategy to address this challenging issue, a new class of hetero‐nanonet (HN) paper batteries based on 1D building blocks of cellulose nanofibrils (CNFs)/multiwall carbon nanotubes (MWNTs) is demonstrated. The HN paper batteries consist of CNF/MWNT‐intermingled heteronets embracing electrode active powders (CM electrodes) and microporous CNF separator membranes. The CNF/MWNT heteronet‐mediated material/structural uniqueness enables the construction of 3D bicontinuous electron/ion transport pathways in the CM electrodes, thus facilitating electrochemical reaction kinetics. Furthermore, the metallic current collectors‐free, CNF/MWNT heteronet architecture allows multiple stacking of CM electrodes in series, eventually leading to user‐tailored, ultrathick (i.e., high‐mass loading) electrodes far beyond those accessible with conventional battery technologies. Notably, the HN battery (multistacked LiNi_0.5Mn_1.5O₄ (cathode)/multistacked graphite (anode)) provides exceptionally high‐energy density (=226 Wh kg^?1 per cell at 400 W kg^?1 per cell), which surpasses the target value (=200 Wh kg^?1 at 400 W kg^?1) of long‐range (=300 miles) electric vehicle batteries. In addition, the heteronet‐enabled mechanical compliance of CM electrodes, in combination with readily deformable CNF separators, allows the fabrication of paper crane batteries via origami folding technique.     

Modified RHKF Filter for Improved DR/GPS Navigation against Uncertain Model Dynamics

In this paper, an error compensation technique for a dead reckoning (DR) system using a magnetic compass module is proposed. The magnetic compass‐based azimuth may include a bias that varies with location due to the surrounding magnetic sources. In this paper, the DR system is integrated with a Global Positioning System (GPS) receiver using a finite impulse response (FIR) filter to reduce errors. This filter can estimate the varying bias more effectively than the conventional Kalman filter, which has an infinite impulse response structure. Moreover, the conventional receding horizon Kalman FIR (RHKF) filter is modified for application in nonlinear systems and to compensate the drawbacks of the RHKF filter. The modified RHKF filter is a novel RHKF filter scheme for nonlinear dynamics. The inverse covariance form of the linearized Kalman filter is combined with a receding horizon FIR strategy. This filter is then combined with an extended Kalman filter to enhance the convergence characteristics of the FIR filter. Also, the receding interval is extended to reduce the computational burden. The performance of the proposed DR/GPS integrated system using the modified RHKF filter is evaluated through simulation.     

基于支持向量机的中文模糊本体映射

Taking into account that fuzzy ontology mapping has wide application and cannot be dealt with in many fields at present, a Chinese fuzzy ontology model and a method for Chinese fuzzy ontology mapping are proposed. The mapping discovery between two ontologies is achieved by computing the similarity between the concepts of two ontologies. Every concept consists of four features of concept name, property, instance and structure. First, the algorithms of calculating four individual similarities corresponding to the four features are given. Secondly, the similarity vectors consisting of four weighted individual similarities are built, and the weights are the linear function of harmony and reliability. The similarity vector is used to represent the similarity relation between two concepts which belong to different fuzzy ontolgoies. Lastly, Support Vector Machine (SVM) is used to get the mapping concept pairs by the similarity vectors. Experiment results are satisfactory.     

全空域电扫共形天线阵设计

探讨了全空域电扫共形天线阵的系统组成,分析了电扫天线阵的设计方式,计算了电扫天线阵的辐射特性。 通过计算表明,该全空域电扫天线阵能有效覆盖方位面00~3600 和俯仰面00~900,可广泛应用于全球宽带电信、导航、 多目标测控、遥感、以及空间监视等领域。     

Continuous Control of Charge Transport in Bi‐Deficient BiFeO3 Films Through Local Ferroelectric Switching

It is demonstrated that electric transport in Bi‐deficient Bi_1‐δFeO₃ ferroelectric thin films, which act as a p‐type semiconductor, can be continuously and reversibly controlled by manipulating ferroelectric domains. Ferroelectric domain configuration is modified by applying a weak voltage stress to Pt/Bi_1‐δFeO₃/SrRuO₃ thin‐film capacitors. This results in diode behavior in macroscopic charge‐transport properties as well as shrinkage of polarization‐voltage hysteresis loops. The forward current density depends on the voltage stress time controlling the domain configuration in the Bi_1‐δFeO₃ film. Piezoresponse force microscopy shows that the density of head‐to‐head/tail‐to‐tail unpenetrating local domains created by the voltage stress is directly related to the continuous modification of the charge transport and the diode effect. The control of charge transport is discussed in conjunction with polarization‐dependent interfacial barriers and charge trapping at the non‐neutral domain walls of unpenetrating tail‐to‐tail domains. Because domain walls in Bi_1‐δFeO₃ act as local conducting paths for charge transport, the domain‐wall‐mediated charge transport can be extended to ferroelectric resistive nonvolatile memories and nanochannel field‐effect transistors with high performances conceptually.     

Ferromagnetic Properties of Five-Period InGaMnAs/GaAs Quantum Well Structure

The effect of Mn was investigated in a synthesized multilayer system made up of five layers of InMnGaAs/GaAs quantum well (QW) grown on semi-insulating (100)-oriented substrates prepared by low-temperature molecular beam epitaxy. Magnetic moment measurements on a superconducting quantum interference device magnetometer revealed the presence of ferromagnetism with a Curie temperature above room temperature in a five-layer InGaMnAs/GaAs QW structure in a GaAs matrix. X-ray diffraction and secondary ion mass spectroscopy measurements powerfully confirmed the second phase founding of ferromagnetic GaMn and MnAs clusters. The ferromagnetism existing in five layers of InMnGaAs/GaAs QW is not intrinsic, but extrinsic due to the presence of Mn dopant clusters such as GaMn and MnAs clusters.     

Highly Efficient Green ZnAgInS/ZnInS/ZnS QDs by a Strong Exothermic Reaction for Down‐Converted Green and Tripackage White LEDs

Highly efficient bright green‐emitting Zn?Ag?In?S (ZAIS)/Zn?In?S (ZIS)/ZnS alloy core/inner‐shell/shell quantum dots (QDs) are synthesized using a multistep hot injection method with a highly concentrated zinc acetate dihydrate precursor. ZAIS/ZIS/ZnS QD growth is realized via five sequential steps: a core growth process, a two‐step alloying–shelling process, and a two‐step shelling process. To enhance the photoluminescence quantum yield (PLQY), a ZIS inner‐shell is synthesized and added with a band gap located between the ZAIS alloy‐core and ZnS shell using a strong exothermic reaction. The synthesized ZAIS/ZIS/ZnS QDs shows a high PLQY of 87% with peak wavelength of 501 nm. Tripackage white down‐converted light‐emitting diodes (DC‐LEDs) are realized using an InGaN blue (B) LED, a green (G) ZAIS/ZIS/ZS QD‐based DC‐LED, and a red (R) Zn?Cu?In?S/ZnS QD‐based DC‐LED with correlated color temperature from 2700 to 10 000 K. The red, green, and blue tripackage white DC‐LEDs exhibit high luminous efficacy of 72 lm W^?1 and excellent color qualities (color rendering index (CRI, R_a) = 95 and the special CRI for red (R₉) = 93) at 2700 K.