Detection and recognition of latent fingerprints play crucial roles in identification and security. However, the separation of sensor, memory, and processor in conventional ex-situ fingerprint ...recognition system seriously deteriorates the latency of decision-making and inevitably increases the overall computing power. In this work, a photoelectronic reservoir computing (RC) system, consisting of DUV photo-synapses and nonvolatile memristor array, is developed to detect and recognize the latent fingerprint with in-sensor and parallel in-memory computing. Through the Ga-rich design, we achieve amorphous GaO
(a-GaO
) photo-synapses with an enhanced persistent photoconductivity (PPC) effect. The PPC effect, which induces nonlinearly tunable conductivity, renders the a-GaO
photo-synapses an ideal deep ultraviolet (DUV) photoelectronic reservoir, thus mapping the complex input vector into a dimensionality-reduced output vector. Connecting the reservoirs and a memristor array, we further construct an in-sensor RC system for latent fingerprint identification. The system maintains over 90% recognition accuracy for latent fingerprint within 15% stochastic noise level via the proposed dual-feature strategy. This work provides a subversive prototype system of DUV in-sensor RC for highly efficient recognition of latent fingerprints.
In this letter, effects of top electrodes (TEs) on ferroelectric properties of Hf 0.5 Zr 0.5 O 2 (HZO) thin films are examined systematically. The remnant polarization (P r ) of HZO thin films ...increases by altering TEs with lower thermal expansions coefficient (<inline-formula> <tex-math notation="LaTeX">\alpha </tex-math></inline-formula>). The largest 2P r value of 38.72 <inline-formula> <tex-math notation="LaTeX">\mu \text{C} </tex-math></inline-formula>/cm 2 is observed for W TE with <inline-formula> <tex-math notation="LaTeX">\alpha = 4.5\times 10^{\mathsf {-6}} </tex-math></inline-formula>/K, while the 2P r value is only <inline-formula> <tex-math notation="LaTeX">22.83~\mu \text{C} </tex-math></inline-formula>/cm 2 for Au TE with <inline-formula> <tex-math notation="LaTeX">\alpha = 14.2\times 10^{\mathsf {-6}} </tex-math></inline-formula>/K. Meanwhile, coercive field (E c ) shifts along the electric field axis and the offset is found to be dependent on the difference of workfunctions (WFs) between TE and TiN bottom electrode (BE). E c shifts toward negative/positive direction, when the WF of TE is larger/smaller (Pt, Pd, Au/W, Al, Ta) than TiN BE. This letter provides an effective way to modulate HfO 2 -based device performance for different requirements in actual application.
Negative‐SET behavior is observed in various cation‐based memories, which degrades the device reliability. Transmission electron microscopy results demonstrate the behavior is caused by the ...overgrowth of the conductive filament (CF) into the Pt electrode. The CF overgrowth phenomenon is suppressed and the negative‐SET behavior is eliminated by inserting an impermeable graphene layer. The graphene‐based devices show high reliability and satisfying performance.
In order to achieve safe and high-efficient photodynamic therapy (PDT), it was a powerful strategy of constructing O2-generated nanozyme with intelligent “off/on” modulation and enhancement. Herein, ...a kind of H2O2-responsive nanozyme was developed for off/on modulation and enhancement of magnetic resonance (MR) imaging and PDT, in which great amounts of gold nanoclusters (AuNCs) were loaded into mesoporous silica to form nanoassembly, and manganese dioxide (MnO2) nanosheets were wrapped as switching shield shell (AuNCs@mSiO2@MnO2). In a neutral physiological environment, stable MnO2 shells eliminated singlet oxygen (1O2) generation to switch off PDT and MR imaging. However, in an acidic tumor microenvironment, the MnO2 shell reacted with H2O2, in which MnO2 degradation switched on MR imaging and PDT, and the generated O2 further enhanced PDT. H2O2-responsive MnO2 degradation brought about excellent MR imaging with a longitudinal relaxation rate of 25.31 mM–1 s–1, and simultaneously sufficient O2 generation guaranteed a 74% high 1O2 yield. Under the irradiation of a 635 nm laser, the viability of MDA-MB-435 cells was reduced to 4%, and the tumors completely disappeared, demonstrating strong PDT performance. Therefore, H2O2-responsive AuNCs@mSiO2@MnO2 nanozyme showed excellent off/on modulation and enhancement of MR imaging and PDT and was a promising intelligent nanoprobe for safe and high-efficiency theranostics.
A highly active CNG1.0-Ni foam electrode was fabricated by electrophoretic deposition method for photoelectrocatalytic pollutants remove and H2 evolution. It exhibited high activity in synergetic ...organic pollutants degradation rate and H2 evolution rate in PEC reaction under visible light (λ > 420 nm) irradiation by using Pt foil as cathode, owing to its excellent visible light respond, high photogenerated electron-hole pairs separation efficiency and robust skeleton.
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•Strong visible light absorption.•Abundant active sites and short migration path of charge carriers.•Fast charge transfer from g-C3N4 to nickel foam through rGO bridge.•High charge carrier separation.•Synergistic H2 evolution and pollutant degradation.
Photoelectrocatalytic (PEC) technique for hydrogen evolution from water splitting and pollutant degradation is one of the most sustainable and environmental approaches for wastewater treatment and energy regeneration. Herein, a porous graphitic carbon nitride (g-C3N4)/reduction graphene oxide (rGO) structure (CNG) is constructed via a solvothermal approach. By using a facile electrophoretic deposition method, CNG is deposited on nickel (Ni) foam with the formation of highly active CNG-Ni foam photoanode. rGO were utilized to load g-C3N4, and also acts as the bridge for accelerating the rate of electron transfer from g-C3N4 to Ni foam. The resulted photoanode exhibits an excellent photoelectrochemical performance for synergistic pollutant degradation and H2 evolution under visible light irradiation (λ > 420 nm). Such excellent PEC activity is attributed to the strong visible-light absorption and fast electron transmission of the as-obtained photoanode. The visible light-driven photocurrent value of the optimal photoanode can be well maintained up to 24 h, indicating its high stability during the PEC process. This work also shows significance for paving a facile route to fabricating highly active photoelectrodes for environmental and energy applications.
Purpose
This study was conducted to evaluate the status of depression and anxiety of healthcare workers and to explore the risk factors during the outbreak of COVID-19 in China.
Methods
A ...cross-sectional study was designed using convenience sampling to obtain a sample of healthcare workers. A structured questionnaire was designed to collect the information of the basic characteristics, workload, and the health condition. Burnout, coping style, anxiety, and depression were measured by specific scales. Multiple logistic regression model was performed to explore the risk factors of anxiety or depression.
Results
There were 902 questionnaires received between February 9, 2020 and February 11, 2020. The proportion of healthcare workers with symptoms of moderate/severe anxiety and moderate/severe depression were 16.63% and 18.29%, respectively. There were 24.50% healthcare workers experiencing moderate/severe anxiety and depression at the same time. The increased workload, respiratory symptoms, digestive symptoms, having done specific test(s) related to COVID-19, having family member needs to be taken care of, negative coping style, and job burnout were the independent risk factors of anxiety. Furthermore, the increased workload, respiratory symptoms, digestive symptoms, having done specific test(s) related to COVID-19, negative coping style, and job burnout were the independent risk factors of depression.
Conclusion
More attention should be paid to the mental health of frontline healthcare workers at the outbreak of COVID-19 in China. Taking steps to reduce the intensity of the work and burnout will be effective to stabilize the mental state of them.
Age-related hearing loss, or presbycusis, is a common cause of hearing loss in elderly people worldwide. It typically presents as progressive, irreversible, and usually affects the high frequencies ...of hearing, with a tremendous impact on the quality of life. Presbycusis is a complex multidimensional disorder, in addition to aging, multiple factors including exposure to noise, or ototoxic agents, genetic susceptibility, metabolic diseases and lifestyle can influence the onset and severity of presbycusis. With the aging of the body, its ability to clean up deleterious substances produced in the metabolic process is weakened, and the self-protection and repair function of the body is reduced, which in turn leads to irreversible damage to the cochlear tissue, resulting in the occurrence of presbycusis. Presently, oxidative stress (OS), mitochondrial DNA damage, low-grade inflammation, decreased immune function and stem cell depletion have been demonstrated to play a critical role in developing presbycusis. The purpose of this review is to illuminate the various mechanisms underlying this age-related hearing loss, with the goal of advancing our understanding, prevention, and treatment of presbycusis.
Abstract
The resistive switching effect in memristors typically stems from the formation and rupture of localized conductive filament paths, and HfO
2
has been accepted as one of the most promising ...resistive switching materials. However, the dynamic changes in the resistive switching process, including the composition and structure of conductive filaments, and especially the evolution of conductive filament surroundings, remain controversial in HfO
2
-based memristors. Here, the conductive filament system in the amorphous HfO
2
-based memristors with various top electrodes is revealed to be with a quasi-core-shell structure consisting of metallic hexagonal-Hf
6
O and its crystalline surroundings (monoclinic or tetragonal HfO
x
). The phase of the HfO
x
shell varies with the oxygen reservation capability of the top electrode. According to extensive high-resolution transmission electron microscopy observations and ab initio calculations, the phase transition of the conductive filament shell between monoclinic and tetragonal HfO
2
is proposed to depend on the comprehensive effects of Joule heat from the conductive filament current and the concentration of oxygen vacancies. The quasi-core-shell conductive filament system with an intrinsic barrier, which prohibits conductive filament oxidation, ensures the extreme scalability of resistive switching memristors. This study renovates the understanding of the conductive filament evolution in HfO
2
-based memristors and provides potential inspirations to improve oxide memristors for nonvolatile storage-class memory applications.
Short-term plasticity and long-term plasticity of bio-synapse are thought to underpin critical physiological functions in neural circuits. In this letter, we vividly emulated the short-term and ...long-term synaptic functions in a single Cu/a-Si/Pt memristor. By controlling the injection quantity of Cu cations into the a-Si layer, the device showed volatile and non-volatile resistive switching behaviors. Owing to the unique characteristics of Cu/a-Si/Pt device, the short-term synaptic functions, i.e., short-term potentiation, pair-pulse facilitation, and long-term functions, i.e., long-term potentiation/depression, spike-timing-dependent plasticity, were mimicked in the memristor successfully. Furthermore, the transition from short-term memory to long-term memory of the device was also observed under repeated stimuli. The experimental results confirm that the Cu/a-Si/Pt memristor with various synaptic behaviors has a potential application in the brain-inspired computing systems.
Active suspension control strategies are a top priority in active suspension system. The current research on active suspension control strategies is mostly focused on two-axle vehicles, and there is ...less research investigating multi-axle vehicles. Additionally, their effective implementation is dependent on accurate mathematical models, and most of them adopt force feedback control, which is vulnerable to external interference. To solve these problems, this paper proposes an active suspension control strategy based on Inertial Measurement Unit. The multi-axle emergency rescue vehicle is made to be equivalent to a 3-degrees-of-freedom parallel mechanism by using the method of grouping and interconnecting the suspension units of the whole vehicle. The attitude change of the vehicle body was transformed into the servo actuator’s displacement by solving the inverse solution of the parallel mechanism position and the action of the servo actuator was driven in reverse according to the displacement obtained. In this way, the vehicle body attitude can be compensated, and the ride comfort and the handling stability of the vehicle can be improved. To verify the effectiveness of the control strategy proposed, the three-axle six vehicle was taken as the research object, the position inverse solution of its equivalent 3-degrees-of-freedom parallel mechanism was deduced, and a high-pass filter was designed. The three-axle vehicle experiment platform integrating active suspension and hydro-pneumatic suspension was built, and the gravel road and slope road experiments were carried out and the results compared with those obtained with hydro-pneumatic suspension. The experiment results showed that, compared with hydro-pneumatic suspension, the active suspension control strategy based on Inertial Measurement Unit proposed in this paper can not only stabilize the body attitude, but also effectively suppress body vibration, improving the ride comfort and handling stability of the vehicle significantly.
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