作者机构：
[杨海君] College of Plant Protection, Hunan Agricultural University, Changsha, 410128, China;[邓蓉蓉] College of Science, Hunan Agricultural University, Changsha, 410128, China;[谭菊; 易勇] Changsha Environmental Monitoring Center Station, Changsha, 410001, China
通讯机构：
[Tan, J.] C;Changsha Environmental Monitoring Center StationChina
期刊：
JOURNAL OF THE ELECTROCHEMICAL SOCIETY,2021年168(1):017514 ISSN：0013-4651
通讯作者：
Zhao, Peng;Wu, Zhiyong;Peng, Chang
作者机构：
[Liu, Yanyan; Zhao, Peng; Zou, Xun; Liu, Jiamin; Xie, Ruirui] Southern Med Univ, Sch Pharmaceut Sci, Guangdong Prov Key Lab New Drug Screening, Guangzhou 510515, Guangdong, Peoples R China.;[Wu, Zhiyong] Southern Med Univ, Coll Tradit Chinese Med, Guangzhou 510515, Guangdong, Peoples R China.;[Peng, Chang] Hunan Agr Univ, Coll Sci, Changsha 410128, Peoples R China.
通讯机构：
[Zhao, Peng; Wu, Zhiyong] S;[Peng, Chang] H;Southern Med Univ, Sch Pharmaceut Sci, Guangdong Prov Key Lab New Drug Screening, Guangzhou 510515, Guangdong, Peoples R China.;Southern Med Univ, Coll Tradit Chinese Med, Guangzhou 510515, Guangdong, Peoples R China.;Hunan Agr Univ, Coll Sci, Changsha 410128, Peoples R China.
关键词：
N, P-rGO;electrochemical sensor;hydroquinone;catechol
摘要：
In this paper, the N and P co-doped reduce graphene oxide (N, P-rGO) was prepared with one-pot solution method and characterized by using SEM and electrochemical technology. It was found that the N, P-rGO has an outstanding conductivity, large surface area and excellent electrocatalytic activity to hydroquinone (HQ) and catechol (CC), which usually coexist in aqueous environment. Under the optimal conditions, compared with bare glassy carbon electrode (GCE) and N doped reduce graphene oxide (N-rGO) modified GCE (N-rGO/GCE), the N, P-rGO/GCE displayed an excellent simultaneous determination towards HQ and CC. And the oxidation peak potential difference of HQ and CC obtained from N, P-rGO/GCE was 106 mV, indicating N, P-rGO/GCE has excellent resolution. The obtained detection limit was 62.1 nM and 99.7 nM for HQ and CC in a concentration range of 1 mu M to 100 mu M, respectively. At the same time, N, P-rGO/GCE also displayed satisfied selectivity, decent stability and desirable reproducibility. Furthermore, the fabricated sensor was successfully applied to detect two isomers in tap water and the recoveries of 99.52% to 106.36% and 95.5% to 103.97% for HQ and CC were obtained, which verified the practical application potential of N, P-rGO/GCE.
关键词：
Multivariate Multifractal Detrended Fluctuation Analysis;Filter;Hurst Surface;Generalized Mean Distance
摘要：
We investigate how various linear and nonlinear filters affect the scaling properties of long-range power-law multivariate synthetic series quantified by multivariate multifractal detrended fluctuation analysis (MV-MFDFA). We consider four types of transforms which are often encountered in physical and physiological processes: linear, nonlinear polynomial, logarithmic and power-law filters. The effect of filters is analyzed by numerical simulation of synthetic series generated by ARFIMA process and binomial multifractal model. The representation of auto-correlation properties of synthetic series before and after the transforms is illustrated by 3D Hurst surface, and the difference of effect is quantified by the proposed generalized mean distance. We find that the linear filters do not change the scaling properties of both synthetic series, while the effect of nonlinear polynomial is correlated with the power of the polynomial filter. For logarithmic and exponential filter, the scaling behavior is not affected for some values of the parameters.
摘要：
The demand for clean and renewable energy has promoted the rapid development of state-of-the-art energy storage electrochemical systems. Vanadium redox flow batteries attract much more attentions due to low cost and high security, unfortunately the low catalytic activity of electrodes for vanadium ion redox process is the main barrier to achieve a high efficiency. This work proposes a novel composite electrode derived from Bacillus mycoides to overcome the dilemma between high degree of graphitization and uniform heteroatom doping. Consequently, this composite electrode simultaneously achieves rapid charge migration and high electrocatalytic activity and enhances the vanadium ion redox reaction on porous lamellar carbon (PLC) materials. Compared with the pristine electrode, the potential polarization for V(IV)//(V) and V(II)/V(III) redox couples on PLC electrode decrease by 254 mV and 278 mV, respectively. Moreover, a high stability for cycling continuously for over 1000 cycles at a high current density of 200 mA cm(-2) and a high energy efficiency can be realized based on PLC electrode. This work not only paves the way to achieve high energy efficiency of vanadium redox flow batteries, but also provides a feasible and novel way to design carbon materials with high catalytic activity and high electronic conductivity.
摘要：
A porous thiolated polymer nanocomposite for sensitive and selective amperometric immunoassay of phyto-hormone (with indole-3-acetic acid (IAA) as the model) was reported, with a detection limit down to 0.13 pg/mL for IAA. Briefly, porous thiolated polymer nanocomposite was prepared via electro-assisted thiol-ene reaction of 2,5-dimercapto-1,3,4-thiadiazole (DMcT) with oxidized polypyrrole (PPy) which was electrosynthesized on a porous graphene (PG) modified glassy carbon electrode, yielding thiolated PPy (TPPy)-PG, then gold nanoparticles (AuNPs) was deposited on the TPPy-PG by electrochemical method to obtain AuNPs/TPPy-PG nanocomposite. Finally, the AuNPs-antibody (Ab)/AuNPs/TPPy-PG nanocomposite film was constructed via the specific chemical reaction between boronic acid functionalized AuNPs/TPPy-PG and the vicinal diol functionalized AuNPs labeled immunoglobulins G (AuNPs-IgG). Scanning electron microscopy (SEM), cyclic voltammetry (CV), ultraviolet visible spectroscopy (UV-vis) and differential pulse voltammetry (DPV) were used to characterize the nanocomposite film and the stepwise modification of the immunosensor. The prepared AuNPs-Ab/AuNPs/TPPy-PG nanocomposite material has uniform dispersion of the AuNPs on porous thiolated polymer nanocomposite as verified by SEM, and high activity of the immobilized Ab proved via DPV. The electrochemical immunosensor show good sensitivity, acceptable selectivity, reproducibility and stability.
摘要：
In the recent years, Mn4+-doped phosphors for indoor plant cultivation have received extensive concern owing to the far-red emission that can match well with the absorption spectra of plant pigments. Whereas, many Mn4+-doped phosphors still face some challenges such as poor light efficiency and low thermal stability. It is an effective way to resolve these problems via cation vacancies engineering. Herein, the Ca14-xAl10Zn6-yO35: Mn4+ phosphors are successfully synthesized by combustion method. The luminescence intensity of Ca14-xAl10Zn6-yO35: Mn4+ phosphor is enhanced through engineering Ca2+ and Zn2+ vacancies according to the charge compensation mechanism. The optimal content of each Ca2+ and Zn2+ vacancy is equal to be 0.3. Furthermore, the defect formation is accompanied with lattice distortion, which plays a vital role in driving the excited phonon traps to reduce the energy loss by non-radiation transitions. Therefore, the thermal stability of Ca14-xAl10Zn6-yO35: Mn4+ phosphor is also improved via engineering cation vacancies. In addition, the Ca14-xAl10Zn6-yO35: Mn4+ phosphors can be effectively excited by blue light and it exhibits far-red emission due to the Mn4+ spin-forbidden E-2 -> (4)A(2) transition. The results suggest that the Ca14-xAl10Zn6-yO35: Mn4+ phosphors can have a tremendous potential in indoor plant cultivation.
摘要：
Double elastic shock waves are rarely observed in two-dimensional (2D) materials and normally unexpected for elastically isotropic 2D crystals such as graphene. With large-scale molecular dynamics simulations, we show that in single-crystal graphene shock-loaded along nonzigzag and nonarmchair directions, double elastic shock waves (quasilongitudinal and quasitransverse) can emerge. Quantitative acoustic wave equation analysis reveals that shock-induced symmetry reduction in lattice, as well as in elastic stiffness tensor, gives rise to the normally unexpected quasitransverse wave following the quasilongitudinal wave.
