Electrostatic Field Enhanced Photocatalytic CO_(2) Conversion on BiVO_(4) Nanowires

The recombination loss of photo-carriers in photocatalytic systems fatally determines the energy conversion efficiency of photocatalysts.In this work,an electrostatic field was used to inhibit the recombination of photo-carriers in photocatalysts by separating photo-holes and photo-electrons in space.As a model structure,(010)facet-exposed BiVO_(4)nanowires were grown on PDMS-insulated piezo-substrate of piezoelectric transducer(PZT).The PZT substrate will generate an electrostatic field under a certain stress,and the photocatalytic behavior of BiVO_(4) nanowires is influenced by the electrostatic field.Our results showed that the photocatalytic performance of the BiVO_(4) nanowires in CO_(2)reduction in the negative electrostatic field is enhanced to 5.5-fold of that without electrostatic field.Moreover,the concentration of methane in the products was raised from 29% to 64%.The enhanced CO_(2) reduction efficiency is mainly attributed to the inhibited recombination loss of photo-carriers in the BiVO_(4) nanowires.The increased energy of photo-carriers and the enhanced surface absorption to polar molecules,which are CO in this case,were also play important roles in improving the photocatalytic activity of the photocatalyst and product selectivity.This work proposed an effective strategy to improve photo-carriers separation/transfer dynamics in the photocatalytic systems,which will also be a favorable reference for photovoltaic and photodetecting devices.

Recent progress in flexible Zn-ion hybrid supercapacitors: Fundamentals, fabrication designs, and applications

One of the most exciting new developments in energy storage technology is flexible Zn-ion hybrid supercapacitors(f-ZIHSCs),which combine the high energy of Zn-ion batteries with high-power supercapacitors to satisfy the needs of portable flexible electronics.However,the development of f-ZHSCs is still in its infancy,and there are numerous barriers to overcome before they can be widely implemented for practical applications.This review gives an up-to-date description of recent achievements and underlying concepts in energy storage mechanisms of f-ZIHSCs and emphasizes the critical role of cathode,anode,and electrolyte materials systems in speeding the prosperity of f-ZIHSCs.The innovative nanostructured-based cathode materials for f-ZIHSCs include carbon(e.g.,porous carbon,heteroatom-doped carbon,biomass-derived porous carbon,graphene,etc.),metal-oxides,MXenes,and metal/covalentorganic frameworks,and other materials(e.g.,activated carbon,phosphorene,etc.)are mainly focused.Afterward,the latest developments in flexible anode and electrolyte frameworks and impacts of electrolyte compositions on the electrochemical properties of f-ZIHSC are elaborated.Subsequently,the advancements based on fabrication designs,including quasi-solid-state,micro,fiber-shaped,and all climate-changed f-ZIHSCs,are discussed in detail.Lastly,a summary of current challenges and recommendations for the future progress of advanced f-ZIHSC are addressed.This review article is anticipated to further understand the viable strategies and achievable approaches for assembling high-performance f-ZIHSCs and boost the technical revolutions on cathode,anode,and electrolytes for f-ZIHSC devices.

高血压、脑梗死患者的心率变异及心律失常研究

目的探究高血压以及脑梗死患者心率变异性与心律失常之间的关系。方法选取2017年1月-2018年1月入院的高血压、脑梗死患者各31例分别作为研究1组与研究2组,另选31例正常患者作为对照组,检测三组患者心率变异性的各项指标的变化,探究高血压、脑梗死患者心率变异性与发生心律失常之间的关系。结果研究1组与研究2组在SDNN、SDANN、p NN50、RMSSD等各指标与对照组相比均明显下降(P<0.05)。研究1组与研究2组的HF、LF、VLF三项指标与对照组相比均明显下降(P<0.05),但是LF/HF数值有升高趋势(P<0.05)。对照组未见心律失常发生;研究1组18例出现心律失常(58.06%);研究2组有16例出现心律失常(51.61%),与对照组相比差异显著(P<0.05)。结论高血压以及脑梗死患者心率变异性指标与患者心律失常之间呈负相关,可以作为临床检测心律失常的一个可靠指标。

Gate-regulated transition temperatures for electron hopping behaviours in silicon junctionless nanowire transistors

We investigate gate-regulated transition temperatures for electron hopping behaviours through discrete ionized dopant atoms in silicon junctionless nanowire transistors.We demonstrate that the localization length of the wave function in the spatial distribution is able to be manipulated by the gate electric field.The transition temperatures regulated as the function of the localization length and the density of states near the Fermi energy level allow us to understand the electron hopping behaviours under the influence of thermal activation energy and Coulomb interaction energy.This is useful for future quantum information processing by single dopant atoms in silicon.

Effect of charge trapping on electrical characteristics of silicon junctionless nanowire transistor

We investigated the effect of charge trapping on electrical characteristics of silicon junctionless nanowire transistors which are fabricated on heavily n-type doped silicon-on-insulator substrate. The obvious random telegraph noise and current hysteresis observed at the temperature of 10 K indicate the existence of acceptor-like traps. The position depth of the traps in the oxide from Si/SiO_(2) interface is 0.35 nm, calculated by utilizing the dependence of the capture and emission time on the gate voltage. Moreover, by constructing a three-dimensional model of tri-gate device structure in COMSOL Multiphysics simulation software, we achieved the trap density of 1.9 × 10^(12) cm^(–2) and the energy level position of traps at 0.18 eV below the intrinsic Fermi level.

Effects of the fertilizer and water management on amino acids and volatile components in Cabernet Sauvignon grapes and wines

The amino acids and the volatile substances in grapes and wines play important roles in their quality,and the concentrations of these substances can be changed by how a vineyard is managed,e.g.,irrigation and fertigation regimes.This study aimed to evaluate the effect of fertilizer and water management on the distribution of amino acids,the volatile component profiles,and the sensory characteristics of Cabernet Sauvignon grapes and wines.The results showed that the amino acid concentration in grape berries was the highest under the 100%local fertilizer rate(HF)and 100%water irrigation quota(HW)treatment,and the volatile component concentration in wine was the highest under HF and 80%water irrigation quota(MW)treatment.The effect of irrigation on the amino acid content in grapes was greater than that of fertigation.The synergistic effect of fertilizer and water on arginine,serine,and glutamine in grape berries was significant.The interactive effect of fertigation and irrigation on the volatile substance in grapes was greater than that of fertigation and irrigation alone.The influence of irrigation on volatile substances in wines was greater than that of fertigation.In addition,there was also a correlation between the concentrations of multiple amino acids in grapes and volatile components in wines.Principal component analysis showed that the wine from the HFMW treatment had the best quality among all treatments.

Bio-Inspired Electromagnetic Protection Based on Neural Information Processing

Electronic systems are vulnerable in electromagnetic interference environment. Although many solutions are adopted to solve this problem, for example shielding, filtering and grounding, noise is still introduced into the circuit inevitably. What impresses us is the biological nervous system with a vital property of robustness in noisy environment. Some mechanisms, such as neuron population coding, degeneracy and parallel distributed processing, are believed to partly explain how the nervous system counters the noise and component failure. This paper proposes a novel concept of bio-inspired electromagnetic protec- tion making reference to the characteristic of neural information processing. A bionic model is presented here to mimic neuron populations to transform the input signal into neural pulse signal. In the proposed model, neuron provides a dynamic feedback to the adjacent one according to the concept of synaptic plasticity. A simple neural circuitry is designed to verify the rationality of the bio-inspired model for electromagnetic protection. The experiment results display that bio-inspired electromagnetic pro- tection model has more power to counter the interference and component failure.

Toward photocatalytic hydrogen generation over BiVO_(4) by controlling particle size

Owing to excellent light absorption and high activity fo r oxygen evolution,monoclinic bismuth vanadate(BiVO_(4)) is regarded as an ideal candidate for photocatalytic water splitting.However,its application is limited by the large particle size in micrometer scale,as well as the slightly positive conduction band.In this work,we successfully synthesized nano-BiVO_(4) with particle size ranged from 27 nm to 57 nm by wet chemical method based on electrostatic spinning method.Unlike bulk BiVO_(4),the nano-sized BiVO_(4) possesses the ability to generate hydrogen by water splitting,and the activity could reach up to1.66 μmol h^(-1) g^(-1) with the assistance of Pt.The enhanced activity is mainly attributed to the improvements resulted from reduced particle size,which includes elevated conduction band,enlarged specific surface area and promoted charge separation.This work provides a simple method for synthesizing photocatalyst with small particle size and high yield.

Dopant atoms as quantum components in silicon nanoscale devices

Recent progress in nanoscale fabrication allows many fundamental studies of the few dopant atoms in various semiconductor nanostructures. Since the size of nanoscale devices has touched the limit of the nature, a single dopant atom may dominate the performance of the device. Besides, the quantum computing considered as a future choice beyond Moore＇s law also utilizes dopant atoms as functional units. Therefore, the dopant atoms will play a significant role in the future novel nanoscale devices. This review focuses on the study of few dopant atoms as quantum components in silicon nanoscale device. The control of the number of dopant atoms and unique quantum transport characteristics induced by dopant atoms are presented. It can be predicted that the development of nanoelectronics based on dopant atoms will pave the way for new possibilities in quantum electronics.

From parabolic approximation to evanescent mode analysis on SOI MOSFET

Subthreshold conduction is governed by the potential distribution. We focus on full two-dimensional（2D） analytical modeling in order to evaluate the 2D potential profile within the active area of Fin FET structure.Surfaces and interfaces, which are key nanowire elements, are carefully studied. Different structures have different boundary conditions, and therefore different effects on the potential distributions. A range of models in Fin FET are reviewed in this paper. Parabolic approximation and evanescent mode are two different basic math methods to simplify the Poisson＇s equation. Both superposition method and parabolic approximation are widely used in heavily doped devices. It is helpful to learn performances of MOSFETs with different structures. These two methods achieved improvement to face different structures from heavily doped devices or lightly doped devices to junctionless transistors.