Lithium metal as an ultimate anode material of future rechargeable batteries may furnish the highest energy density for its pairing cathode, although preventing the growth of lithium dendrites in ...liquid electrolytes is a major challenge. This work reports that stable lithium metal anodes can be achieved by charging with high‐frequency sinusoidal ripple current generated by rotating triboelectric nanogenerators (R‐TENGs). Compared with constant DC current charging, sinusoidal ripple current charging by R‐TENG improves the uniformity of lithium deposition during cycling test. Consequently, symmetric Li/Li cells exhibit lower overpotential and better cycling stability. In addition, full cells assembled with lithium metal anodes and LiFePO4 cathodes show considerably improved capacity retention when charged by R‐TENG's sinusoidal ripple current (99.5%) compared to constant current (78.7%) after 200 cycles. The charging strategy device in this work provides a promising direction toward improving the cycle life of Li metal batteries. In addition, the combination of R‐TENGs with Li metal batteries offers an encouraging solution for achieving stable energy supply in self‐powered systems.
Stable lithium metal anodes are attained when charged by a rotary triboelectric nanogenerator which generates a sinusoidal ripple current. Improved lithium deposition morphology and cycle life of lithium metal batteries are achieved via sinusoidal ripple current charging than square wave current and constant current charging due to suppressed lithium dendrite growth.
Harvesting biomechanical energy is an important route for providing electricity to sustainably drive wearable electronics, which currently still use batteries and therefore need to be charged or ...replaced/disposed frequently. Here we report an approach that can continuously power wearable electronics only by human motion, realized through a triboelectric nanogenerator (TENG) with optimized materials and structural design. Fabricated by elastomeric materials and a helix inner electrode sticking on a tube with the dielectric layer and outer electrode, the TENG has desirable features including flexibility, stretchability, isotropy, weavability, water-resistance and a high surface charge density of 250 μC m
. With only the energy extracted from walking or jogging by the TENG that is built in outsoles, wearable electronics such as an electronic watch and fitness tracker can be immediately and continuously powered.
The phenomenon of contact electrification (CE) has been known for thousands of years, but the nature of the charge carriers and their transfer mechanisms are still under debate. Here, the CE and ...triboelectric charging process are studied for a metal–dielectric case at different thermal conditions by using atomic force microscopy and Kelvin probe force microscopy. The charge transfer process at the nanoscale is found to follow the modified thermionic‐emission model. In particular, the focus here is on the effect of a temperature difference between two contacting materials on the CE. It is revealed that hotter solids tend to receive positive triboelectric charges, while cooler solids tend to be negatively charged, which suggests that the temperature‐difference‐induced charge transfer can be attributed to the thermionic‐emission effect, in which the electrons are thermally excited and transfer from a hotter surface to a cooler one. Further, a thermionic‐emission band‐structure model is proposed to describe the electron transfer between two solids at different temperatures. The findings also suggest that CE can occur between two identical materials owing to the existence of a local temperature difference arising from the nanoscale rubbing of surfaces with different curvatures/roughness.
The effect of temperature on contact electrification (CE) is investigated at the nanoscale. It is found that hotter materials tend to be positively charged while cooler materials tend to be negatively charged in CE. Based on the results, an electron thermal‐emission model is proposed. The temperature effect provides strong evidence for electron transfer in CE.
Quantum teleportation provides a 'disembodied' way to transfer quantum states from one object to another at a distant location, assisted by previously shared entangled states and a classical ...communication channel. As well as being of fundamental interest, teleportation has been recognized as an important element in long-distance quantum communication, distributed quantum networks and measurement-based quantum computation. There have been numerous demonstrations of teleportation in different physical systems such as photons, atoms, ions, electrons and superconducting circuits. All the previous experiments were limited to the teleportation of one degree of freedom only. However, a single quantum particle can naturally possess various degrees of freedom--internal and external--and with coherent coupling among them. A fundamental open challenge is to teleport multiple degrees of freedom simultaneously, which is necessary to describe a quantum particle fully and, therefore, to teleport it intact. Here we demonstrate quantum teleportation of the composite quantum states of a single photon encoded in both spin and orbital angular momentum. We use photon pairs entangled in both degrees of freedom (that is, hyper-entangled) as the quantum channel for teleportation, and develop a method to project and discriminate hyper-entangled Bell states by exploiting probabilistic quantum non-demolition measurement, which can be extended to more degrees of freedom. We verify the teleportation for both spin-orbit product states and hybrid entangled states, and achieve a teleportation fidelity ranging from 0.57 to 0.68, above the classical limit. Our work is a step towards the teleportation of more complex quantum systems, and demonstrates an increase in our technical control of scalable quantum technologies.
The binding mechanism of molecular interaction between diosmetin and human serum albumin (HSA) in a pH 7.4 phosphate buffer was studied using atomic force microscopy (AFM) and various spectroscopic ...techniques including fluorescence, resonance light scattering (RLS), UV-vis absorption, circular dichroism (CD), and Fourier transform infrared (FT-IR) spectroscopy. Fluorescence data revealed that the fluorescence quenching of HSA by diosmetin was a static quenching procedure. The binding constants and number of binding sites were evaluated at different temperatures. The RLS spectra and AFM images showed that the dimension of the individual HSA molecules were larger after interaction with diosmetin. The thermodynamic parameters, ΔH° and ΔS° were calculated to be -24.56 kJ mol-1 and 14.67 J mol-1 K-1, respectively, suggesting that the binding of diosmtin to HSA was driven mainly by hydrophobic interactions and hydrogen bonds. The displacement studies and denaturation experiments in the presence of urea indicated site I as the main binding site for diosmetin on HSA. The binding distance between diosmetin and HSA was determined to be 3.54 nm based on the Förster theory. Analysis of CD and FT-IR spectra demonstrated that HSA conformation was slightly altered in the presence of diosmetin.
LS3DF, namely linear scaling three-dimensional fragment method, is an efficient linear scaling ab initio total energy electronic structure calculation code based on a divide-and-conquer strategy. In ...this paper, we present our GPU implementation of the LS3DF code. Our test results show that the GPU code can calculate systems with about ten thousand atoms fully self-consistently in the order of 10 min using thousands of computing nodes. This makes the electronic structure calculations of 10,000-atom nanosystems routine work. This speed is 4.5–6 times faster than the CPU calculations using the same number of nodes on the Titan machine in the Oak Ridge leadership computing facility (OLCF). Such speedup is achieved by (a) carefully re-designing of the computationally heavy kernels; (b) redesign of the communication pattern for heterogeneous supercomputers.
Background and Aim
Chinese herbal medicine (CHM), as well as Western medicine (WM), is an important cause of drug‐induced liver injury (DILI). However, the differences between CHM and WM as agents ...implicated in liver injury have rarely been reported.
Methods
Overall, 1985 (2.05%) DILI cases were retrospectively collected from the 96 857 patients hospitalized because of liver dysfunction in the 302 Military Hospital between January 2009 and January 2014.
Results
In all the enrolled patients with DILI, CHM was implicated in 563 cases (28.4%), while 870 cases (43.8%) were caused by WM and the remaining patients (27.8%) by the combination of WM and CHM. Polygonum multiflorum was the major implicated CHM. Compared with WM, the cases caused by CHM showed more female (51 vs 71%, P < 0.001) and positive rechallenge (6.1 vs 8.9%, P = 0.046), a much greater proportion of hepatocellular injury (62.2 vs 88.5%, P < 0.001), and a higher mortality (2.8 vs 4.8%, P = 0.042); however, no differences in the rates of chronic DILI and ALF were found (12.9 vs 12.4%, P = 0.807; 7.6 vs 7.6%, P = 0.971). Based on Roussel Uclaf Causality Assessment Method, 75.6% of cases caused by CHM were classified as probable and only 16.6% as highly probable, significantly different from WM (38.4 and 60.3%, all P < 0.001).
Conclusions
The causal relationship between CHM and liver injury is much complex, and the clinical characteristics of DILI caused by CHM differ from those caused by WM.
Powder spreading process is to use a spreader such as blade or roller to spread powder layers for subsequent fusion in powder bed fusion additive manufacturing. In this work, the effects of various ...spreader geometries on powder spreading are examined by discrete element method (DEM). The results show that a compact region in the powder pile exists. Round and inclined surfaces of blade spreaders allow more particles in the compact region to be deposited compared with vertical blades, thus the powder layer formed is denser. However, they exert larger forces on the underlying part. Inhomogeneity of powder layers is caused by particle burst phenomenon, which is due to particle motion conflict in the compact region rather than large forces. Roller system has largest particle motion conflict thus powder layers formed are sparse and inhomogeneous with small layer gaps. Size segregation in blade systems is not as severe as roller systems.
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•Powder spreading process with different spreaders is simulated by DEM.•Round and inclined blades deposit more powders than vertical blades.•Round and inclined blades exert larger forces on the underlying part.•Large layer gap has better homogeneity and smaller force fluctuation.•Round blade system has the least size segregation.
The preparation of high‐quality perovskite films is important for achieving high‐performance perovskite solar cells (PSCs). The effective balance between solvent and antisolvent is an essential ...factor for regulating high‐quality perovskite film during the spin‐coating and thermal‐annealing steps. In this work, a greener, nonhalogenated, nontoxic bifunctional (anti)solvent, methyl benzoate (MB), is developed not only as an antisolvent to rapidly generate crystal seeds at the perovskite spin‐coating step, but also as a digestive‐ripening solvent for the perovskite precursors, which can prevent the loss of organic components during the thermal‐annealing stage and effectively suppress the formation of miscellaneous lead halide phases. As a result, this novel bifunctional (anti)solvent is employed in planar n–i–p PSCs for engineering high‐quality perovskite layers and thus achieving a power conversion efficiency up to 22.37% with negligible hysteresis and >1300 h stability. Moreover, due to the high boiling point and low‐volatility characteristic of MB, high‐performance PSCs are achieved reproducibly at different operating temperatures (22–34 °C). Therefore, this developed bifunctional solvent system can provide a promising platform toward globally upscaling and commercializing PSCs in all seasons and regions.
A novel bifunctional (anti)solvent system is developed for regulating the perovskite crystallization procedure. It can perform not only as an antisolvent at the spin‐coating step to rapidly generate crystal seeds, but also as a solvent for ripening the precursors to large crystal grains during the thermal‐annealing process. Therefore, it can significantly enhance the efficiency, stability, and reproducibility of perovskite solar cells.
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