Improved electrochemical performance of a cyclic ultracapacitor using slurry electrodes under various flow conditions

A cyclic ultracapacitor is a promising energy storage device that can be used for grid energy storage. The cyclic ultracapacitor combines the advantages of both ultracapacitors and flow batteries, enabling rapid charging and large‐scale energy use. To improve the electrochemical performance under the flow condition, it is necessary to find a more electrical active material and design a flow cell that minimizes the resistance. In this study, we investigate the effects of changing the ratio of the active material in a slurry electrode under various operating conditions. Slurry electrodes were prepared with different ratios of active material and conductive additive but with a fixed electrolyte amount. Voltage–time curves of both a single and a stack‐flow cell in the constant‐current mode were obtained to analyze the relationship between the active materials ratio and the cell performance. Having more adsorption sites according to the active material amount is more important than increasing the electric conductivity by the conductive additive amount with regard to cell performance capabilities in a low resistance condition such as a non‐flow mode. However, higher electrical conductivity on a slurry electrode is more beneficial to improve the electrochemical performance in the stack‐flow mode, which has harsh resistance levels. Copyright © 2017 John Wiley & Sons, Ltd.     

In vitro culture of Boletus badius as a source of indole compounds and zinc released in artificial digestive juices

Food Science and Biotechnology - The objective of this study was to obtain the in vitro cultures of Boletus badius under controlled conditions and investigate the release of indole compounds and...     

A survey on decision making for task migration in mobile cloud environments

The key idea of MCC is using powerful back-end computing nodes to enhance capabilities of small mobile devices and provide better user experiences. An effective and widely used approach to realize this is task migrations. Decision making is an important aspect of migrations which affects the feasibility and effectiveness of task migrations. There have been a number of research efforts to MCC which help make decisions for task migrations. In this paper, we present a comprehensive survey on decision making for task migrations in MCC, including decision factors and algorithms. We observe that there are still some challenges such as comprehensive context awareness, unified migration standards, large-scale experiments, more involvement of latest achievements from artificial intelligence, and flexible decision-making mechanisms. The paper highlights these issues and challenges to attract more efforts to work on MCC.     

Differential graphical games for H∞ control of linear heterogeneous multiagent systems

Differential graphical games have been introduced in the literature to solve state synchronization problem for linear homogeneous agents. When the agents are heterogeneous, the previous notion of graphical games cannot be used anymore and a new definition is required. In this paper, we define a novel concept of differential graphical games for linear heterogeneous agents subject to external unmodeled disturbances, which contain the previously introduced graphical game for homogeneous agents as a special case. Using our new formulation, we can solve both the output regulation and H_∞ output regulation problems. Our graphical game framework yields coupled Hamilton‐Jacobi‐Bellman equations, which are, in general, impossible to solve analytically. Therefore, we propose a new actor‐critic algorithm to solve these coupled equations numerically in real time. Moreover, we find an explicit upper bound for the overall ‐gain of the output synchronization error with respect to disturbance. We demonstrate our developments by a simulation example.     

Spring Maize Yield Estimation based on Radiation Use Efficiency and Multi-temporal Remotely Sensed Data

In order to develop highly accurate model for crop yield estimation,an approach of retrieving regional crop yield was studied by Radiation Use Efficiency (RUE) and remote sensing data,the Jifangzha irrigation is of Hetao irrigation district of Inner Mongolia Autonomous Region was selected as a research case.Based on this model,the difference of the Dry Matter Accumulation (DMA) between the maize’s different growing stages is made and a comparative analysis of the measured yields,and the predicted results based on this model.The results show that the DMA of the maize’s jointing stage is maximal,about 40% of total amount.The measured yield and the predicted ones based on the model has a greater correlation,the Correlation Coefficient was 0.853 and passed the reliability of 0.01.The difference of the DMA in different growing stages showed that the sensitive degree was displayed between main growing stages and yield,and that were some key aspects:the main limiting factor in growing stages and raising yield.These results indicate the model for spring maize yield estimation is feasible and effective based on the RUE and multi-temporal remotely sensing data.     

Intensify the application of ZnO-based nanodevices in humid environment: O2/H2 plasma suppressed the spontaneous reaction of amorphous ZnO nanowires

In this work, we have demonstrated that amorphous ZnO nanobranches (a-ZnO NBs) could spontaneously react from the crystalline ZnO NWs (c-ZnO NWs) at specific humid environment. The spontaneous reaction mechanism and result can be analyzed by humidity controlling and optical microscope (OM)/scanning electron microscope (SEM)/Kelvin probe force microscopy (KPFM)/transmission electron microscopy (TEM) system. We can make the c-ZnO NWs spontaneous reaction happen at different humid environments and suppress the a-ZnO NBs spontaneous reaction by oxygen/hydrogen plasma surface passivation. The hydrogen plasma surface treatment also can improve the UV sensing sensitivity more than twofold. This work provides the mechanism and methods of the a-ZnO NBs spontaneous growth and offers the passivation treatment for strengthening and enhancing ZnO-based nanodevice application in humid environment and UV light detection, respectively.     

EH40高强度船板Z向拉伸性能分析

利用扫描电镜及能谱仪对EH40的断口形貌、夹杂进行分析,结果表明：硫化物对钢板厚度方向抗层状撕裂性能的影响较大。为满足钢材Z向性能的要求,冶炼过程中应尽量控制硫的含量。     

Deformation-induced crystal–crystal transition of polybutene-1: an in situ FTIR imaging study

Crystal–crystal transition of polybutene-1 from forms II to I inside and outside a large hedrite or spherulite during deformation is investigated with in situ Fourier transform infrared sepectroscopic imaging technique and miniature tensile tester. Three stages have been observed for both of samples. In the first stage (strain ε < 0.2), form I crystal formed slowly under the effect of deformation. When entering the second stage II (0.2 < ε < 1.2), the crystal–crystal transition was accelerated significantly. In the third stage, form II translates into form I almost completely. It was also found that the transition rate inside large hedrite and spherulite is slightly faster than the surrounding initially, especially for the hedrite. However, the difference inside and outside becomes negligible when ε > 0.8. We proposed that the difference in crystal–crystal transformation between spherulite and hedrite is attributed to the different alignment of lamellar stacks in two samples. The results demonstrate the effect of different morphologies on the crystal–crystal transition during deformation.     

A simple method for preparing graphene nano-sheets at low temperature

Graphene nano-sheets (GNs) with high quality were successfully synthesized in a Teflon-lined container through a low temperature expansion process. The influence factors of expansion temperature, expansion mode and reduction time on the morphology and structure of products have been systematically investigated, and an optimum experimental condition for the synthesis of GNs has been obtained. The results showed that the Teflon-lined container is an effective apparatus for preparing GNs at relative low temperature (<300 °C). The low temperature synthetic process is simple, inexpensive and easy to scale up in comparison with the traditional method which often consume more energy, use more complicated instruments, or more costly. The electrochemical properties of the as-synthesized products were investigated as anode materials for lithium ion batteries.