As a promising high-capacity anode material for Li-ion batteries, NiMn2O4 always suffers from the poor intrinsic conductivity and the architectural collapse originating from the volume expansion ...during cycle. Herein, a combined structure and architecture modulation is proposed to tackle concurrently the two handicaps, via a facile and well-controlled solvothermal approach to synthesize NiMn2O4/NiCo2O4 mesocrystals with superlattice structure and hollow multi-porous architecture. It is demonstrated that the obtained NiCo1.5Mn0.5O4 sample is made up of a new mixed-phase NiMn2O4/NiCo2O4 compound system, with a high charge capacity of 532.2 mAh g-1 with 90.4% capacity retention after 100 cycles at a current density of 1 A g-1. The enhanced electrochemical performance can be attributed to the synergistic effects of the superlattice structure and the hollow multi-porous architecture of the NiMn2O4/NiCo2O4 compound. The superlattice structure can improve ionic conductivity to enhance charge transport kinetics of the bulk material, while the hollow multi-porous architecture can provide enough void spaces to alleviate the architectural change during cycling, and shorten the lithium ions diffusion and electron-transportation distances.
As a promising high-capacity anode material for Li-ion batteries, NiMn
O
always suffers from the poor intrinsic conductivity and the architectural collapse originating from the volume expansion ...during cycle. Herein, a combined structure and architecture modulation is proposed to tackle concurrently the two handicaps, via a facile and well-controlled solvothermal approach to synthesize NiMn
O
/NiCo
O
mesocrystals with superlattice structure and hollow multi-porous architecture. It is demonstrated that the obtained NiCo
Mn
O
sample is made up of a new mixed-phase NiMn
O
/NiCo
O
compound system, with a high charge capacity of 532.2 mAh g
with 90.4% capacity retention after 100 cycles at a current density of 1 A g
. The enhanced electrochemical performance can be attributed to the synergistic effects of the superlattice structure and the hollow multi-porous architecture of the NiMn
O
/NiCo
O
compound. The superlattice structure can improve ionic conductivity to enhance charge transport kinetics of the bulk material, while the hollow multi-porous architecture can provide enough void spaces to alleviate the architectural change during cycling, and shorten the lithium ions diffusion and electron-transportation distances.
With the rapid advancement of in-process measurements and sensor technology driven by zero-defect manufacturing applications, high-dimensional heterogeneous processes that continuously collect ...distinct physical characteristics frequently appear in modern industries. Such large-volume high-dimensional data place a heavy demand on data collection, transmission, and analysis in practice. Thus, practitioners often need to decide which informative data streams to observe given the resource constraints at each data acquisition time, which poses significant challenges for multivariate statistical process control and quality improvement. In this article, we propose a generic online nonparametric monitoring and sampling scheme to quickly detect mean shifts occurring in heterogeneous processes when only partial observations are available at each acquisition time. Our innovative idea is to seamlessly integrate the Thompson sampling (TS) algorithm with a quantile-based nonparametric cumulative sum (CUSUM) procedure to construct local statistics of all data streams based on the partially observed data. Furthermore, we develop a global monitoring scheme of using the sum of top-r local statistics, which can quickly detect a wide range of possible mean shifts. Tailored to monitoring the heterogeneous data streams, the proposed method balances between exploration that searches unobserved data streams for possible mean shifts and exploitation that focuses on highly suspicious data streams for quick shift detection. Both simulations and a case study are comprehensively conducted to evaluate the performance and demonstrate the superiority of the proposed method.
Sliding Mode Control and Adaptive Control are widely studied in the area of Rotor UAV in recent years. Although the performance of Rotor UAV with these controllers show high command tracking ability ...and good robustness, they are limited by model accuracy so that they cannot take place PID. In this paper, a novel method named State damping control is proposed to be a candidate for the traditional PID method. Our proposed State Damping Control is inspired by the format of air resistance. The method is based on the general idea that resistance will make a system easy to stabilize. State damping control is independent of model accuracy and just uses three parameters to control attitude, so it is easy to realize. Krasovskii Theorem is used to give the evidence that State damping control is asymptotic stable in our considered state space. Finally, simulations are implemented in C++ on VS2017, it demonstrates that State damping control is easy to be tuned and robust to wind attack and inertial parameters. Compared with PID, our proposed method is robust to wind disturbances obviously.
Improvisational behavior is an individual’s spontaneous and creative behavior in the face of emergencies, using existing material and emotional resources to respond quickly and effectively to ...uncertain situations. Despite increasing interest in this behavior, its antecedents remain unclear, with particular ambiguity regarding the relationship between empowering leadership and employee improvisational behavior. The present article addresses this ambiguity with the theory of reasoned action to examine whether the impact of empowering leadership on employees’ improvisational behavior is determined by employees’ attitudes toward such behavior. In this study, a multi-source design was adopted, and data (339 valid samples) were collected from five Internet companies in China’s Jiangsu and Zhejiang provinces. Hierarchical regression and bootstrapping methods were used to test the hypotheses. The results reveal that (1) employees’ promotion focus moderates the relationship between empowering leadership and improvisational behavior and (2) employees’ willingness to take risks mediates the moderating effect of promotion focus. Our findings demonstrate employees’ attitudinal utility in explaining when improvisational behavior is most likely to occur under empowering leadership.
In this article, we focus on a joint scheduling problem that considers the corrective maintenance (CM) due to unexpected breakdowns and the scheduled preventive maintenance (PM) in a generic ...<inline-formula> <tex-math notation="LaTeX">M </tex-math></inline-formula>-machine flow shop. The objective is to find the optimal job sequence and PM schedule such that the total of the tardiness cost, PM cost, and CM cost is minimized. Currently, most existing studies on the PM schedules are based on a fixed PM interval, which is rigid and may lead to poor performance, as the fixed strategy fails to effectively balance the trade-offs between the production scheduling and maintenance. To address this critical research issue, our novel idea is to dynamically update the PM interval based on the real-time machine age, such that the maintenance activity coordinates with the job scheduling to the maximum extent, which results in an overall cost saving. Specifically, a correction factor is introduced to dynamically update the PM interval and to help evaluate whether it is worthwhile to process the job first at the risk of the CM before performing the PM action. To demonstrate the effectiveness of the adaptive strategy, simulations and a case study on mining operations are conducted to show that the adaptive strategy outperforms the existing methods with a less total cost. Note to Practitioners -This article is motivated by the critical problem of balancing the trade-offs between production scheduling and maintenance in a flow shop production line, where jobs are processed on the machines in the same route. On the one hand, production scheduling aims to meet the customer demands on time. On the other hand, the maintenance actions help restore the machines' reliability by reducing the machine failure rate. Most existing approaches to scheduling the PM are based on the fixed PM interval, which is rigid and may lead to poor performance. Although the nonperiodic PM interval strategy has been proposed in the literature for production scheduling, it still does not consider the adaptive PM strategy in the context of flow shop scheduling with multiple machines. To fill this literature gap, in this article, we first model a generic <inline-formula> <tex-math notation="LaTeX">M </tex-math></inline-formula>-machine flow shop considering both the CM and PM. Then, we suggest a new adaptive and easy-to-implement approach to dynamically update the PM interval and improve the decision-making on the PM schedules. Compared with the conventional maintenance policy, the adaptive one greatly reduces the total cost in real-time scheduling.
In this paper, an absorptive coding metasurface (ACM) is proposed for ultra-wideband radar cross section (RCS) reduction, the design process is presented in detail, in which a lossy polarization ...conversion metasurface (PCM) is proposed at first. The lossy PCM is an anisotropic resistive structure with both polarization conversion and absorption performances, so that its co-polarization reflection coefficients under u- and v-polarized incidences can be kept at less than - 10 dB in magnitude in the frequency range from 7.5 to 45.2 GHz. Though the magnitude of the cross-polarization reflection coefficient cannot be very small only due to the absorption, its phase will be changed by nearly 180° when the unit-cell structure of the lossy PCM is rotated by 90°. Thus, the lossy PCM can be used as one of the two types of lossy coding elements for an ACM when its unit-cell structure is rotated by 90° or not. Based on the lossy PCM, an ACM is proposed. The simulation and experimental results show that the ACM has an excellent RCS reduction performance under arbitrary polarized incidence, it can achieve effective RCS reduction under normal incidence in the ultra-wide frequency band from 7.4 to 45.5 GHz with a ratio bandwidth (f
/f
) of 6.15:1; moreover, an ultra-wideband RCS reduction can still be achieved when the incident angle is increased to 45°, which indicates that the ACM has good stealth performance under the detection of various radars working in X, Ku, K and Ka bands, it is very practical.
The aim of this work is to explore the possibility of using the phenolic monoterpenes (PMs) as leading compounds with antifungal activity against plant disease. The in vitro antifungal activities of ...carvacrol and thymol against seven kinds of plant pathogenic fungi were evaluated on mycelium growth rate method, and the results showed that carvacrol and thymol exhibited broad spectrum antifungal activity. Structure requirement for the antifungal activity of PMs was also investigated. The preliminary conclusion was that phenolic hydroxyl and monoterpene were basic structures for the antifungal activity of PMs, and the position of phenolic hydroxyl showed less effect. Ester derivatives of carvacrol and thymol were more effective than carvacrol and thymol against plant pathogenic fungi. We suggested that carvacrol, thymol and their ester derivatives could potentially be used as new fungicide leading compounds.
Objective: Observational studies have shown the association between iron status and osteoarthritis (OA). However, due to difficulties of determining sequential temporality, their causal association ...is still elusive. Based on the summary data of genome-wide association studies (GWASs) of a large-scale population, this study explored the genetic causal association between iron status and OA. Methods: First, we took a series of quality control steps to select eligible instrumental SNPs which were strongly associated with exposure. The genetic causal association between iron status and OA was analyzed using the two-sample Mendelian randomization (MR). Inverse-variance weighted (IVW), MR-Egger, weighted median, simple mode, and weighted mode methods were used for analysis. The results were mainly based on IVW (random effects), followed by sensitivity analysis. IVW and MR-Egger were used for heterogeneity testing. MR-Egger was also used for pleiotropy testing. Leave-one-SNP-out analysis was used to identify single nucleotide polymorphisms (SNPs) with potential impact. Maximum likelihood, penalized weighted median, and IVW (fixed effects) were performed to further validate the reliability of results. Results: IVW results showed that transferrin saturation had a positive causal association with knee osteoarthritis (KOA), hip osteoarthritis (HOA) and KOA or HOA (p < 0.05, OR > 1), and there was a negative causal association between transferrin and HOA and KOA or HOA (p < 0.05, OR < 1). The results of heterogeneity test showed that our IVW analysis results were basically free of heterogeneity (p > 0.05). The results of the pleiotropy test showed that there was no pleiotropy in our IVW analysis (p > 0.05). The analysis results of maximum likelihood, penalized weighted median and IVW (fixed effects) were consistent with our IVW results. No genetic causal association was found between serum iron and ferritin and OA. Conclusions: This study provides evidence of the causal association between iron status and OA, which provides novel insights to the genetic research of OA.
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