轨道交通基于LTE-M的综合承载系统架构设计与实施

针对轨道交通基于LTE-M的综合承载系统建设需求,描述承载业务特点、无线覆盖方式、电源及同步时钟需求等一系列具体工程建设中需考量的因素。对数据与集群EPC核心合设与分设的2种不同的系统组网架构进行比较分析,为解决LTE-M工程应用中遇到的问题提供参考、建议。     

Malaysia’s electricity market structure in transition

The Malaysian electricity industry evolved from a vertically integrated utility into a single-buyer model, which considered a precursor to deregulation and a competitive market. This study considers electricity sector reform in Malaysia and proposes a market structure for the industry. We focus on the single-buyer model and the pool model for the analysis with the recommendation on reform stages required to ensure a smooth and successful market transition. A smooth transition from regulated market into deregulated market will ensure market stability and sustainability of the energy market. It will also provide enough time for the market participants to adapt and transit from regulated to deregulated energy market.     

掘进机电液双控系统的研究

 在掘进机智能化发展过程中，远程遥控和机载控制并存状态是必不可少的。掘进机一般采用电液双控系统来实现该功能，但实践中采用电液双控系统会出现液控动作缓慢的问题。当掘进机装载运输同时动作并采用液控操作时，装运马达转速缓慢甚至停转，严重影响正常工作。结合现场故障现象，分析掘进机电液双控系统的工作原理及各元件原理，排除故障并进行深入研究。基于现有技术条件，提出改造方案并选择可行方案试验，最终从根本上解决问题。     

Distribution-free double-sampling precedence monitoring scheme to detect unknown shifts in the location parameter

In most applications, parametric monitoring schemes are used to monitor the majority of industrial and nonindustrial processes in order to improve the quality of the outputs or services. However, parametric monitoring schemes are known to underperform when the normality assumption is not met or when there is not enough information about the symmetry or asymmetry nature of the process underlying distribution. Hence, in this paper, a new nonparametric Phase II Shewhart-type double-sampling (DS) monitoring scheme based on the precedence statistic is proposed in order to efficiently monitor quality processes when the underlying process distribution departs from normality. The performance is investigated using the average run length (ARL), standard deviation of the run length (SDRL), expected ARL (EARL) and expected average number of observations to signal (EANOS), and the average sample sizes (ASS) metrics. The latter metrics are computed using Monte Carlo simulation and exact formulae. In general, it is shown that the new DS precedence scheme outperforms the existing basic Shewhart precedence scheme with and without supplementary runs rules in many situations. A real-life illustrative example based on a filling process of milk bottles is provided to demonstrate the application and implementation of the new DS precedence monitoring scheme.     

Influence of ball milling duration on the morphology,features of the structural-phase state and microhardness of 3Ni-Al powder mixture

The features of changes in the morphology, structural-phase state and microhardness of 3Ni-Al powder mixture after different duration of high-energy ball-milling have been studied. Three main stages of the evolution of the structural-phase state were revealed, which, corresponding to different duration of treatment, differ in the morphology of the powder mixture, distribution of components, phase compositions and the nature of changes in microhardness. It was found that under high-energy ball-milling conditions, the synthesis of intermetallic Ni₃Al and NiAl phases begins at much lower temperatures compared to the phase diagram. It is shown that an increase in the duration of high-energy ball-milling is accompanied by a transformation of the phase composition, the features of which determine the level of strengthening of the powder mixture studied.     

Tailoring the hydrophilic and hydrophobic reaction fields of the electrode interface on single crystal Pt electrodes for hydrogen evolution/oxidation reactions

Interfacial hydrophobic/hydrophilic reaction fields significantly affect various reactions at the electrode surface. The hydrogen evolution reaction (HER) and the hydrogen oxidation reaction (HOR) have been investigated on single crystal Pt electrodes modified with hydrophobic/hydrophilic cations and anion-exchange copolymers in alkaline solutions. In alkali metal hydroxide solutions, Pt (110) exhibits the highest HER/HOR activity in the low-index planes of Pt. On the low-index planes of Pt, the hydrophilicity of the alkali metal cation in the supporting electrolyte activates the HER/HOR depending on its hydration energy. Hydrophilic cations at the interface facilitate the extraction of hydrogen from the hydrated water. The modification of anion-exchange copolymers with a hydrophobic skeleton on Pt (110) further enhanced the HER/HOR activity. The hydrogen bonding network formed around the hydrophobic species facilitated the mobility of water molecules and the OH⁻ as the reactant/product of the HER/HOR. Appropriately forming hydrophilic and hydrophobic reaction fields at the interface improved the HER/HOR activity.     

Effect of biohydrogen by overexpressing small RNA RyhB combined with ldh impairment in novel Klebsiella sp. FSoil 024

Biotechnological hydrogen production is considered as an environmentally sustainable alternative to petrochemical sources or electrolysis. Here, disruption of lactate dehydrogenase (LDH) and metabolic regulation via the small RNA RyhB were adopted to improve hydrogen production in the novel Klebsiella sp. strain FSoil 024. The hydrogen production of FSoil 024-L (Δldh) and FSoil 024-L/R (Δldh/RyhB) from glucose in a 5-L fermenter respectively increased by 40 and 50% compared to the wild type. When glycerol was adopted as a more favorable substrate, FSoil 024-L generated 3.3 L/L of hydrogen after 52 h of fermentation, implying its great potential for the utilization of crude glycerol to produce hydrogen. Overexpression of RyhB downregulated formate biosynthesis in FSoil 024, thereby redirecting NADH toward the hydrogen production pathway. This finding provides new insights into the role of cellular reducing power in hydrogen metabolism and establishes a rationale for improving hydrogen production.     

A new synthetic metamodel methodology for liquid‐propellant engine's cooling system optimization

The present paper strives for optimization of the cooling system of a liquid‐propellant engine (LPE). To this end, the new synthetic metamodel methodology utilizing the design of experiment method and the response surface method was developed and implemented as two effective means of designing, analyzing, and optimizing. The input variables, constraints, objective functions, and their surfaces were identified. Hence, the design and development strategy of combustion chamber and nozzle was clarified, and 64 different experiments were carried out on the RD‐161 propulsion system, of which 47 experiments were approved and compatible with the problem constraints. This engine used all three modes of cooling: the radiation cooling, the regenerative cooling, and the film cooling. The response surface curves were drawn and the related objective function equations were obtained. The analysis of variance results indicate that the developed synthetic model is capable to predict the responses adequately within the limits of input parameters. The three‐dimensional response surface curves and contour plots have been developed to find out the combined effects of input parameters on responses. In addition, the precision of the models was assessed and the output was interpreted and analyzed, which showed high accuracy. Therefore, the desirability function analysis has been applied to LPE's cooling system for multiobjective optimization to maximize the total heat transfer and minimize the cooling system pressure loss simultaneously. Finally, confirmatory tests have been conducted with the optimum parametric conditions to validate the optimization techniques. In conclusion, this methodology optimizes the LPE's cooling system, a 2% increase in the total heat transfer, and a 38% decrease in the pressure loss of the cooling system. These values are considerably large for the LPE design.     

基于知识蒸馏算法的电缆专业知识库应用

电缆全寿命周期内的标准、规程、法规是电缆从业人员开展工作的依据,而齐全、权威且方便查阅的标准和规程是指导电缆各项工作开展和城市电网安全稳定运行的重要保障。介绍了所开发的电缆专业知识库系统,基于小规模样本知识蒸馏算法,实现电缆专业知识库的关键词匹配搜索、笔记摘抄学习以及论坛的学习探讨等功能,提升了电缆从业人员查阅资料、员工学习的效率。