白水峪电站闸门控制系统改造

根据白水峪电站原闸门控制系统存在的问题 ,提出闸门控制系统改造思路 ,介绍了改造后的闸门控制系统的硬件配置和功能     

How to carry out assembly line–cell conversion? A discussion based on factor analysis of system performance improvements

The line–cell (or line–seru) conversion is an innovation of assembly systems that has received less attention. Its essence is dismantling an assembly conveyor line and adopting a mini-assembly unit, called seru (or cell). In this paper, we discuss how to do such line–cell conversions, especially focusing on assembly cell formation (ACF) and assembly cell loading (ACL). We perform 64 arrays of full factorial experiment analysis that incorporate three factors: work stations, product types, and product lot sizes. We construct a two-objective line–cell conversion model that minimises the total throughput time (TTPT) and the total labour hours (TLH). Three non-dominated solutions obtained from the two-objective model are used to evaluate the performance of the line–cell conversion. By investigating the experimental results of the ACF and the ACL, we summarise several managerial insights that could be used to help successful line–cell conversions.     

Porous sheet-like and sphere-like nano-architectures of SnO2 nanoparticles via a solvent-thermal approach and their gas-sensing performances

Porous sheet-like and sphere-like nano-architectures of SnO₂ nanoparticles have been prepared via a solvent-thermal approach in the absence of any surfactant or polymer templates by simply changing the volume ratio of DMF to water. The nano-materials have been characterized by FESEM, XRD, IR, TEM and BET. A mechanism for the formation of nano-architectures is also proposed based on the assembly behaviors of DMF in water. The gas sensors constructed with porous sphere-like SnO₂ nano-architectures exhibit much higher sensitivity to the reduce vapors tested, compared to those from porous sheet-like SnO₂ materials, while the sheet-like materials show better selectivity to ethanol. The nano-architectures fabricated with the facile method are promising candidates for building chemical sensors with tunable performances.     

平晶表面形状加压分析判断法的原理与应用探讨

平晶表面形状的判断对于平晶平面度的计算非常重要，错误的判断将会直接导致计算错误。该文通过对加压分析判断法原理的介绍，讨论在实际检定工作中的注意事项。灵活掌握该方法不仅对于平晶检定工作，而且在使用平晶测量量具或工件表面平面度时都非常重要。     

Polyoxometalate-based catalysts for photocatalytic,chemical catalytic and electrocatalytic water oxidation

Complex [Fe₁₁ (H₂O)₁₄(OH)₂(W₃O₁₀)₂(α-SbW₉O₃₃)₆]^27?(2) has been studied independently under photocatalytic or chemical catalytic or electrocatalytic conditions by our group. (1) Under the optimal photocatalytic conditions (photoirradiation at λ = 420 nm, [Ru(bpy)₃](ClO₄)₂ as the photosensor, Na₂S₂O₈ as the oxidant in borate buffer (pH = 10.0)], the turnover number (TON) can reach as high as 1815, the initial quantum yield and the initial turnover frequency (TOF) for the first 60 s was 47% and 6.3 s^?1, respectively. (2) We report herein that 2 are highly active homogeneous water oxidation catalysts when [Ru(bpy)₃]³⁺ is used as the terminal oxidant, with a turnover number (TON) of higher than 78. (3) The current densities achieved during cyclic voltammetry (CV) show that 2 exhibit no electrocatalytic activity at pH 10.0. This study discusses the catalytic behaviors and mechanism of 2 in different experimental conditions (driving forces) for water oxidation.     

Physical modeling of deep ground excavation in geologically horizontal strata based on infrared thermography

This study was committed to the simulation of a roadway excavation in the geologically horizontal strata at great depth based on physical modeling test. A new approach of Physically Finite Elemental Slab Assemblage (PFESA) was employed for construction of the large-scale physical model simulating roadway excavation in stratified rocks. The roadway excavation without support in our test was designed as two phases, i.e. phase 1: full-face excavation and phase 2: staged excavation. The experimental test was carried out under the deep ground stress condition of unbalanced confinement. Rock response to the excavation was monitored and captured in real-time and over the entire field by using infrared (IR) thermography, incorporated with such image processing procedures as data statistics, noise removal and two-dimensional DFT (Discrete Fourier Transformation) for extracting features from the resulting thermographies. IRT, defined as the statistical mean value of the IR image matrix, was used as a measure of rock response, characterizing the full-face excavation, the staged excavation as a linear process and a non-linear process respectively by its time-Marching scheme within the IR radiation domain. The denoised IR images and the two-dimension Fourier spectra provide an enhanced understanding of the excavation response in terms of initiation, propagation and coalescence of rock damage in the spatial and frequency regimes respectively.     

厚薄承台界定的新方法和梁式模型法的修正

大量的试验与研究结果均表明,梁式模型法适用于多桩薄承台设计,对于厚承台并不适用。通过对国内外桩基承台试验数据统计,确定空间桁架方法和梁式模型方法应用于承台的界限,也即如何定义"薄"承台和"厚"承台;并且通过对试验数据的数学统计,考虑承台底层纵筋对抗剪和抗冲切的有利作用,对梁式模型法的冲切和剪切公式进行了修正。     

湿地与南方高校校园功能一体化探索——华侨大学厦门校区生态规划

总结华侨大学厦门校区校园的生态规划实践与探索,提出湿地与校园功能一体化模式,包括融合市政功能、替代环境功能、兼容景观功能3部分,贯穿规划、建设与运行全过程,以扭转城市化过程对生态的"建设性破坏"。     

Synthesis and conductivity of heptadecatungstovanadodiphosphoric heteropoly acid with Dawson structure

A new solid high-proton conductor, heptadecatungstovanadodiphosphoric heteropoly acid H₇P₂W₁₇VO₆₂·28H₂O with Dawson structure was synthesized by the stepwise acidification and the stepwise addition of element solutions. The optimal proportion of component compounds in the synthesis reaction was given. The product was characterized by chemical analysis, potentiometric titration, IR, UV, XRD, ³¹P NMR, TG-DTA and electrochemical impedance spectroscopy (EIS). The results indicate that H₇P₂W₁₇VO₆₂·28H₂O possesses the Dawson structure. EIS measurements show a high conductivity (3.10 × 10⁻² S cm⁻¹ at 26 °C and 75% relative humidity), with an activation energy of 32.23 kJ mol⁻¹ for proton conduction. The mechanism of proton conduction for this heteropoly acid is Vehicle mechanism.