Competitive Coordination of Sodium Ions for High-Voltage Sodium Metal Batteries with Fast Reaction Speed.

The unstable electrode-electrolyte interface and the narrow electrochemical window of normal electrolytes hinder the potential application of high-voltage sodium metal batteries. These problems are actually related to the solvation structure of the electrolyte, which is determined by the competition between cations coordinated with anions or solvent molecules. Herein, we design an electrolyte incorporating ethyl (2,2,2-trifluoroethyl) carbonate and fluoroethylene carbonate, which facilitates a pronounced level of cation-anion coordination within the solvation sheath by enthalpy changes to reduce the overall coordination of cation-solvents and increase sensitivity to salt concentration. Such an electrolyte regulated by competitive coordination leads to highly reversible sodium plating/stripping with extended cycle life and a high Coulombic efficiency of 98.0%, which is the highest reported so far in Na||Cu cells with ester-based electrolytes. Moreover, 4.5 V high-voltage Na||Na3V2(PO4)2F3 cells exhibit a high rate capability up to 20 C and an impressive cycling stability with an 87.1% capacity retention after 250 cycles with limited Na. The proposed strategy of solvation structure modification by regulating the competitive coordination of the cation provides a new direction to achieve stable sodium metal batteries with high energy density and can be further extended to other battery systems by controlling enthalpy changes of the solvation structure.

High-Performance Neuromorphic Computing and Logic Operation Based on a Self-Assembled Vertically Aligned Nanocomposite SrTiO3:MgO Film Memristor.

Neuromorphic computing based on memristors capable of in-memory computing is promising to break the energy and efficiency bottleneck of well-known von Neumann architectures. However, unstable and nonlinear conductance updates compromise the recognition accuracy and block the integration of neural network hardware. To this end, we present a highly stable memristor with self-assembled vertically aligned nanocomposite (VAN) SrTiO3:MgO films that achieve excellent resistive switching with low set/reset voltage variability (4.7%/-5.6%) and highly linear conductivity variation (nonlinearity = 0.34) by spatially limiting the conductive channels at the vertical interfaces. Various synaptic behaviors are simulated by continuously modulating the conductance. Especially, convolutional image processing using diverse crossbar kernels is demonstrated, and the artificial neural network achieves an overwhelming recognition accuracy of up to 97.50% for handwritten digits. Even under the perturbation of Poisson noise (λ = 10), 6% Salt and Pepper noise, and 5% Gaussian noise, the high recognition accuracies are retained at 95.43%, 94.56%, and 95.97%, respectively. Importantly, the logic memory function is proven experimentally based on the nonvolatile properties. This work provides a material system and design idea to achieve high-performance neuromorphic computing and logic operation.

Silicon based Bi0.9La0.1FeO3 ferroelectric tunnel junction memristor for convolutional neural network application.

Computing in memory (CIM) based on memristors is expected to completely solve the dilemma caused by von Neumann architecture. However, the performance of memristors based on traditional conductive filament mechanism is unstable. In this study, we report a nonvolatile high-performance memristor based on ferroelectric tunnel junction (FTJ) Pd/Bi0.9La0.1FeO3 (6.9 nm) (BLFO)/La0.67Sr0.33MnO3 (LSMO) on a silicon substrate. The conductance of this device was adjusted by different pulse stimulation parameter to achieve various synaptic functions because of ferroelectric polarization reversal. Based on the multiple conductance characteristics of the devices and the high linearity and symmetry of weight updating, image processing and VGG8 convolutional neural network (CNN) simulation based on the devices were realized. Excellent results of the image processing are demonstrated. The recognition accuracy of CNN offline learning reached an astonishing 92.07% based on Cifar-10 dataset. This provides a more feasible solution to break through the bottleneck of von Neumann architecture.

Cervical adenofibroma without clinical symptoms: report of a rare case.

Adenofibroma is an extremely rare benign biphasic tumour composed of glandular and fibrous tissues. It occurs more often in the endometrium but it can also occur in the cervix and extrauterine sites. This case report describes a 39-year-old asymptomatic woman with cervical adenofibroma. The patient was treated successfully with surgical removal of the tumour. As adenofibromas are very rare, the report is presented with a brief review of the literature.

[The Hydrothermal Synthesis, Structure and Spectroscopy Study on (H2dap)6H[V12B16O54(OH)4] · 12H2O (dap = 1, 2-diaminopropane)].

A polyoxovanadium borate (H2 dap)6H[V12B16O54(OH)4] · 12H2O (dap=1,2-diaminopropane) with novel structure was hydrothermally synthesized and characterized by the single crystal X-ray diffraction. It crystallizes in triclinic system with space group Piand unit cell parameters a=19.027(4), b=16.142(3) Å, c=26.679(5) Å, α=90°, ß=101.06(3)°, γ=90°, V=8042(3) Å3, Z=4, Dc=1.962 g · cm(-3), µ=1.456 mm(-1), F(000)=4776, the final R1=0.0626, wR2=0.1927, S=1.003,for 7635 observed reflections with I>2σ(I). It is showed that the compound 1 is composed of V12B16 clusters unit and dap which is as a counter ion, and a two-dimensional layered structure is obtained by the effect of hydrogen bonding between the cluster units and dap, and between the layers via strong hydrogen bonds to form a three-dimensional supramolecular structure. The compound 1 were also characterized by IR, two-dimensional infrared (2D IR) correlation spectroscopy with magnetic and thermal perturbation, UV/Vis DRS spectra. The relationship between the structure and spectroscopy properties was discussed. The IR spectrum showed that the antisymmetric stretching vibration absorption peak νas (V-Oµ) and symmetric stretching vibration absorption peaks νs (V-Oµ) appeared at 775 and 683 cm(-1) respectively, whereas the vibration absorption peak in ν(B-O) of BO3 and the vibration absorption peak in ν(B-O) of BO4 appeared at 1350 and 1050 cm(-1) respectively. The response of the stretching vibrations of B-O and V-O was detected in the 2D IR correlation spectra with magentic perturbation. In addition, the response of the stretching vibrations of B-OH, B-O and V-O-V was detected in the 2D IR correlation spectra with thermal perturbation.