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Electrocatalysts with high cost-effectiveness for the oxygen reduction reaction (ORR) are essential for fuel cells (FC) and Zn-Air batteries (ZAB), which need highly active sites and suitable carbon substrates to accelerate the charge transfer kinetics. Herein, a simple and extensible method using ball milling and space-confinement pyrolysis is reported to prepare a series of transition metals and N-C catalysts (M-NLPC), which possess three-dimensional porous carbon substrates and dense active sites for efficient ORR. M-NLPC catalysts (especially Fe-NLPC) exhibit outstanding ORR activity with a half-wave potential (

As one of complications of diabetes mellitus, diabetic nephropathy is related to renal dysfunction. Membrane metalloendopeptidase (MME) is associated with the pathogenesis of diabetic nephropathy and exerts a protective function in high glucose (HG)-treated podocytes. Salviolone, one of important bioactive components from Salvia miltiorrhiza, possesses an anti-inflammatory activity. However, the roles of salviolone in renal mesangial cell dysfunction under HG condition remain unknown. The targets of salviolone in diabetic nephropathy were predicted by bioinformatics analysis. Relative mRNA level of MME was detected by qPCR in HG-treated human renal mesangial cells (HRMCs). Cell viability was analyzed using CCK-8 assay. Cell proliferation was investigated by EdU staining. Oxidative stress was evaluated by detection of ROS generation and levels of oxidative stress-related biomarkers. The inflammatory cytokines and fibrosis-related biomarkers were examined by ELISA. Our results showed that MME expression was decreased in diabetic nephropathy and HG-treated HRMCs. Salviolone increased MME level in HG-treated HRMCs. Salviolone mitigated HG-induced HRMC proliferation by increasing MME expression. Salviolone attenuated HG-induced ROS generation, MDA level increase, and SOD activity decrease through upregulating MME expression. Moreover, salviolone suppressed HG-induced increase of levels of TNF-α, IL-1β, IL-6, fibronectin, and collagen IV through upregulating MME expression. In conclusion, salviolone attenuates proliferation, oxidative stress, inflammation, and fibrosis in HG-treated HRMCs through upregulating MME expression.

Metal-free electrocatalysts for the oxygen reduction reaction (ORR) are the desired materials for metal–air batteries. Here, low-cost metal-free electrocatalysts of N-doped graphene supported on N-rGO nanosheets (N-graphene@N-rGO) using the composites of copper-based metal–organic frameworks (Cu-BTC) supported on GO (Cu-BTC@GO) for the efficient ORR are reported. The dispersant of GO was introduced into the structure to prevent the aggregation of Cu-BTC, and Cu-BTC could also provide steric hindrance to prevent the GO nanosheets from being stacked. The results indicate that N-graphene@N-rGO had more excellent ORR performance, better durability, and better methanol tolerance than 20 wt% Pt/C in alkaline solution. In addition, the peak power density of a two-electrode zinc–air (Zn–air) battery assembled with N-graphene@N-rGO as the cathode was 139 mW cm−2, which was higher than that of 20 wt% Pt/C (120 mW cm−2). Therefore, N-graphene@N-rGO using the synergy of N-graphene and N-rGO is a promising candidate compared to precious metal-based electrocatalysts for efficient Zn–air batteries.

This study investigates delay-dependent stability of a class of highly non-linear stochastic functional differential equations with Markovian switching. Some novel boundedness and stability criteria are first established, including stability in , asymptotic stability in and almost surely asymptotic stability, based on Lyapunov functions and generalised Ito formula. Concretely, the authors generalise and improve the existing results to the hybrid stochastic functional differential equations case. An example is presented to illustrate the effectiveness of the obtained results.

Although Pt-based oxygen reduction reaction (ORR) catalysts have excellent performance, they are expensive and suffer from poor durability. It is necessary to explore carbon-based ORR electrocatalysts with low cost, high specific surface area, large porosity, and strong chemical stability. Herein, we have synthesized a zinc-based metal–organic framework precursor (Zn-BTC) using a simple solvothermal method. Then, carbonization and N doping have been carried out by means of high-temperature pyrolysis, ultimately affording metal-free 3D hollow spherical O and N dual-doped graphene framework composites (O,N-graphene) with an average diameter of about 4 μm and specific surface area as high as 1801.4 m2 g−1. O,N-Graphene has superior ORR electrocatalytic activity with an onset potential Eonset = 1.01 V vs. RHE and a half-wave potential E1/2 = 0.842 V vs. RHE, which are comparable with commercial 20 wt% Pt/C with a 4-electron reduction process. The O,N-graphene catalyst shows better durability and methanol tolerance at a lower cost than commercial 20 wt% Pt/C. The peak power density of O,N-graphene as the cathode of a traditional Zn-air battery is 152.8 mW cm−2, which is higher than that of a commercial 20 wt% Pt/C battery (119.8 mW cm−2). Our findings indicate that synergy among the 3D hollow structure, large specific surface area, highly conductive graphene framework, and pyridine N and graphite N defects left in O,N-graphene accelerated O2 diffusion and increased catalytically active sites, thereby affording superior ORR and improved Zn-air battery performance under alkaline conditions.

This paper presents the work a development of data cleaning and analysis for on-board diagnostic system (OBD II) data. The OBD device can collect speed and mass air flow via ECU, from which the instantaneous fuel consumptions are also calculated, along with the vehicle trajectories collected by an integrated GNSS module. Therefore, a large vehicle trips survey collects trajectories and instantaneous fuel consumption of over 8000 vehicles. The large trajectory database consists a number of trips whose positioning failures are significantly higher than the average. The datasets are proceeded with quantitative analysis to identify the faulty trip data by fitting with the power law distribution. After the cleanup, the analysis results demonstrate that the datasets can deliver a reliable estimation of the average daily passenger car fuel consumption across Beijing.

This study investigates the stability of a class of neutral stochastic functional differential equations with Markovian switching. Some novel stability criteria are first established, including boundedness, pth moment exponential stability and almost sure exponential stability, based on multiple Lyapunov functions, generalised Ito formula and non-negative semi-martingale convergence theorem. Concretely, the authors generalise the existing results under the essential neutral term and improve the diffusion operators from being controlled by two auxiliary functions to other multiple auxiliary functions with not only constant coefficients but also time-varying coefficients. Some numerical examples are presented to illustrate the effectiveness of the obtained results.

We consider a hybrid SDE (stochastic differential equation) with variable delays, which is unstable and its coefficients satisfy some polynomial growth conditions. We want to find a variable-delays feedback control such that the controlled hybrid SDE with variable delay becomes stable. We establish some novel stability criteria of the controlled SDE with variable delays. Our results improve the existing results from hybrid SDEs with constant-delays to hybrid SDEs with variable-delays. Finally, an example is given to confirm our results.

Summary This paper investigates the stability of linear stochastic delay differential equations with infinite Markovian switchings. Some novel exponential stability criteria are first established based on the generalized It o formula and linear matrix inequalities. Then, a new sufficient condition is proposed for the equivalence of 4 stability definitions, namely, asymptotic mean square stability, stochastic stability, exponential mean square stability with conditioning, and exponential mean square stability. In particular, our results generalize and improve some of the previous results. Finally, two examples are given to illustrate the effectiveness of the proposed results.

This paper studies the stability of hybrid neutral stochastic differential equations with unbounded delay. Some novel exponential stability criteria and boundedness conditions are established based on the generalized Itô formula and Lyapunov functions. The factor e-εδ(t) is used to overcome the difficulties caused by the unbounded delay δ(t) effectively. In particular, our results generalize and improve some previous stability results from bounded delay to unbounded delay conditions. Finally, an example is presented to demonstrate the effectiveness of the proposed results.

The author investigates the relationships of some potential objects for a right Markov process and the same objects for the Girsanov transformed process induced by α-excessive function including Revuz measures, energy functionals, capacities and Levy systems in this paper.

Micro-media is a new media form under the new technical system. The research work of this study is mainly to: (1) Summarize the research results of scholars and redefine the concept of micro-media; (2) Conclude the characteristics of the micromedia and list currently active smartphone software about micro-media; (3) Discuss current situation and influences of micro-media in the aspects of traditional media, public opinion and education. In addition, these can provide reference for relevant studies.

Nannochloropsis sp., one kind of green microalgae cultivated autotrophically and axenically in laboratory, is used as raw material to produce biodiesel by one-step method in an amended reactor. The effects of several reaction parameters on transesterification over Mg–Zr solid base catalyst were investigated through both conventional method and one-step method. One-step method could give a higher yield of methyl ester than conventional two-step method, which demonstrates that the present one-step method is suitable for biodiesel production from the microalgae Nannochloropsis sp. Moreover, the present one-step method realizes the convenient in situ separation of catalyst from microalgae residue which can be easily used consequently, reducing the procedure units as well as the overall costs.

SO 4 2− /ZrO 2 –MoO 3 (SZM), SO 4 2− /ZrO 2 –Nd 2 O 3 (SZN) and SO 4 2− /ZrO 2 –MoO 3 –Nd 2 O 3 (SZMN) solid acids catalysts were prepared and characterized by XRD, NH 3 -FTIR, NH 3 -TPD and TG–DTG. The activities and stabilities of the catalysts for the esterification of fatty acids were investigated. Experimental and characterization results show that the excellent activity and stability of SZMN are attributed to the firm combination of sulfur species with t -ZrO 2 . The co-addition of Mo and Nd increases the dispersion of t -ZrO 2 and stabilizes the structure of small-crystallite t -ZrO 2 , which is favorable to increasing the acid sites amount, strengthening the acidity, and then enhancing the activity and stability of the catalyst.

The existence and uniqueness of the local generalized solution to the initial boundary value problem for the three-dimensional damped nonlinear hyperbolic equation u t t + k 1 ∇ 4 u + k 2 ∇ 4 u t + ∇ 2 g ( ∇ 2 u ) = 0 , ( x , t ) ∈ Ω × ( 0 , T ) , u = 0 , ∇ 2 u = 0 , ( x , t ) ∈ ∂ Ω × ( 0 , T ) , u ( x , 0 ) = u 0 ( x ) , u t ( x , 0 ) = u 1 ( x ) , x ∈ Ω ⊂ R 3 are proved. The paper arrives at some sufficient conditions for blow up of the solutions in finite time by two methods. An example is given.

We consider a more general wealth process with a drift coefficient which is Lipschitz continuous and the portfolio process with convex constraint. We convert the problem of hedging American contingent claims into the problem of minimal solution of backward stochastic differential equation with stopping time. We adopt the penalization method for constructing the minimal solution of stochastic differential equations and obtain the upper hedging price of American contingent claims.

Electroluminescence performances are improved by inserting a semiconductor zinc oxide (ZnO) buffer layer into the emissive tris-(8-hydroxyquinoline)aluminum (Alq 3 ) layer and the semitransparent Al/Ag cathode in top-emitting organic light-emitting diodes (TEOLEDs) with structures of Si/SiO 2 /Ag/Ag 2 O/4,4′, 4″-tris(3- methylphenylphenylamino)triphenylamine/ 4,4′-bis[ N -(1-naphthyl-1-)- N -phenyl- amino]-biphenyl/Alq 3 /ZnO/Al/Ag. The thermal deposition of ZnO layer onto Alq 3 results in Alq 3 anion formation, which is beneficial to electron injection by generating some new energy levels in the forbidden band of Alq 3 . In addition, a large hole-injection barrier of ∼2 eV at the interface of Alq 3 /ZnO effectively blocks hole injection into Al/Ag cathode, leading to more carrier recombination in the emissive region.

Let {X(t), t ⩾ 0} be a recurrent right process with state space ( E , E ) where E is a Polish space and E is the Borel σ-algebra of E. The purpose of the present paper is to study some problems about the invariant measure and the ergodic property of the process.

Efficient phosphorescent white organic light-emitting diodes (WOLEDs) were realized by using a bright blue-emitting layer, iridium (III) bis-[(4,6- di-fluoropheny)-pyridinato-N, C2'] picolinate doped 4.4'-bis-(9-carbazolyl)-2, 2'-dimethyl–biphenyl doped, together with tris-(2-phenylpyridine) iridium and bis-(1-phenyl–isoquinoline) acetylacetonate iridium (III) are codoped into a 4,4'-N,N'-dicarbazole- biphenyl layer to provide blue, green and red emission for colour mixing. The device emission colour is controlled by varying dopant concentrations and the thicknesses of blue and green–red layers as well as tuning the thickness of an exciton-blocking layer. The maximum luminance and power efficiency of the WOLED are 42700 cd m−2 at 17 V and 8.48 lm W−1 at 5 V, respectively. The Commission Internationale de 1'Eclairage (CIE) chromaticity coordinate changes from (0.41, 0.42) to (0.37, 0.39) when the luminance ranges from 1000 cd m−2 to 30000 cd m−2.

In this paper, we shall establish a representation formula for transition density function of a certain type of right processes under Girsanov transform and give the infinitesimal generator of the transformed process.

A top-emitting organic light-emitting device (TOLED) with an architecture of Si/SiO2/Ag/Ag2O/4, 4', 4''-tris(3-methylphenylphenylamino) triphenylamine/4, 4'-bis[N-(1-naphthyl-1-)-N-phenyl-amino]-biphenyl/ tris-(8-hydroxyquinoline) aluminium (Alq3)/LiF/Al/semitransparent Ag is designed with the resonance wavelength in the TOLED corresponding to the emission peak of Alq3. With this optimized cavity structure, light magnification with a coefficient of ~16 (in the forward direction) is observed, leading to significantly improved performances such as a brightness of 100529 cd m−2 (12.5 V), a large luminous efficiency of 10.4 cd A−1 (7 V) and an external quantum efficiency of 2.94% (5 V).

This paper expatiates on two image segmentation methods based on the improved fuzzy c-means (FCM) clustering algorithms. In the first method named as the method based on the two-dimensional histogram, each clustering sample is a two-dimensional vector structured the gray-level value of each pixel and mean value of each pixel neighborhood. In the second method named as the method considering pixel spatial information, clustering objective function, clustering center and membership function are modified by means of pixel spatial information. Both the first method and the second method take into account pixel spatial information by means of different techniques. The application to segmentation of a sonar image of a small underwater target shows that the first method is as effective as the second method.

This paper expatiates on the improved fuzzy c-means (FCM) clustering algorithm. In the algorithm, the membership values are determined via the improved method, and the number of the centers of FCM clustering are determined via the number of the peaks of the two-dimensional histogram on the gray-level values of pixels and gradient values of pixel neighborhoods. The application to segmentation of a sonar image of a small underwater target shows that the improved FCM clustering algorithm can segment the image into the shadow and echo regions of the target, and that the improved algorithm is more intelligent and timesaving than the traditionary FCM clustering algorithm.

We consider a general wealth process with a drift coefficient which is a function of the wealth process and the portfolio process with convex constraint. Existence and uniqueness of a minimal solution are established. We convert the problem of hedging American contingent claims into the problem of minimal solution of backward stochastic differential equation, and obtain the upper hedging price of American contingent claims.

This paper expatiates on the principle, process and key technique of the enhancement algorithm based on fuzzy set theory. In the algorithm, the critical point g c is determined via the Otsu algorithm based on the two-dimensional histogram, and then the fuzzy set of an image is determined via the exponential function, and then the fuzzy set is transformed for enhancement via a recursive operator, and eventually the enhanced image is attained via an inverse transformation from the transformed fuzzy set. Acting as an application to the image of high-voltage transmission lines, the experimental results of not only the transformation of histogram equalization but also the expatiated algorithm are given. The experimental results show the latter is more efficient than the former. One of main characteristics in the expatiated algorithm is that g c is determined via the Otsu algorithm based on the two-dimensional histogram instead of the others.