Interactive Iconized Grammar-Based Pailou Modelling

Pailous are representative Chinese architectural works used for commemoration. However, their geometric structure and semantic construction rules are too complex for quick and intuitive modelling using traditional modelling tools. We propose an intuitive modelling system for the stylized creation of pailous for novices. Our system encapsulates structural components as icons and semantic layouts as topological graphs, using which users create and manipulate icons with topological recommendations. The interpreter automatically and immediately transforms a graph to its corresponding model using built-in components with the proposed parametric L-system grammars derived from architectural rules. Using this system to re-create existing representative pailous and design imaginary ones yields results with the desired visual complexities. In comparison to Maya, a 3D modelling tool, when modelling a pailou and toukung, our system is effective and simple, and eliminates the need to remember and understand complex rules.     

纸箱印刷机参数化设计系统的研究与开发

为提高纸箱印刷机的设计效率,研究了基于SolidWorks的二次开发技术,并用Visual Basic作为编程工具开发了基于SolidWorks的“纸箱印刷机参数化设计系统”。该系统具有零件三维建模、结构分析、装配及工程图输出等功能,实践证明其能高效、正确地实现纸箱印刷机的参数化设计,能大大提高纸箱印刷机的设计效率。本系统的开发研究揭示了参数化设计系统开发的一般规律,这对参数化设计系统的开发具有一定的参考意义。     

约克冷冻机组高压电动机控制系统改进

平煤神马20万t/aPVC工程冷冻站约克冷冻机组控制与高压开关柜二次控制不一致,通过添加继电器并反复试验改进形成可行的方案,满足了工程使用要求,此方法可为同类问题的解决提供可行的方案。     

Deposition and characterization of IrOx nanofoils on carbon nanotube templates by reactive magnetron sputtering

Large surface area IrO_x nanofoils (IrO_xNF) were deposited on multi-wall carbon nanotube (MWCNT) templates, forming IrO_x/MWCNT nanocomposites, by reactive radio frequency magnetron sputtering using Ir metal target. The structural and spectroscopic properties of IrO_xNF were characterized. The micrographs of field emission scanning electron microscopy showed the formation of foil-like structure for the as-deposited samples. Transmission electron microscopy analysis revealed the contiguous presence of glassy iridium oxide, iridium metal, and iridium dioxide nanocrystals in the foil. X-ray photoelectron spectroscopy analysis provided the information of the oxidation states and the stoichiometry of IrO_xNF. Raman spectra revealed the amorphous-like phase of the as-deposited IrO_xNF. The nanofoil structure provided ultra-high surface area for electrical charge storage which made the IrO_x/MWCNT nanocomposites as an attractive candidate for the supercapacitor applications.     

NXOR- or XOR-based robust template decomposition for cellular neural networks implementing an arbitrary Boolean function via support vector classifiers

Robust template design for cellular neural networks (CNNs) implementing an arbitrary Boolean function is currently an active research area. If the given Boolean function is linearly separable, a single robust uncoupled CNN can be designed preferably as a maximal margin classifier to implement the Boolean function. On the other hand, if the linearly separable Boolean function has a small geometric margin or the Boolean function is not linearly separable, a popular approach is to find a sequence of robust uncoupled CNNs implementing the given Boolean function. In the past research works using this approach, the control template parameters and thresholds are usually restricted to assume only a given finite set of integers. In this study, we try to remove this unnecessary restriction. NXOR- or XOR-based decomposition algorithm utilizing the soft margin and maximal margin support vector classifiers is proposed to design a sequence of robust templates implementing an arbitrary Boolean function. Several illustrative examples are simulated to demonstrate the efficiency of the proposed method by comparing our results with those produced by other decomposition methods with restricted weights.

     

Cobalt selenide electrocatalyst supported by nitrogen-doped carbon and its stable activity toward oxygen reduction reaction

We have prepared durable catalysts of CoSe₂/N-carbon using low-cost raw materials, measured their activities, peroxide yields, stabilities in reducing molecular oxygen, and characterized their crystalline phases and morphology. CoSe₂/N-carbon is featured with an active support, N-carbon, which by itself shows high stability as evidenced in its small activity decay. After 1000 CV cycles, the half-wave potential (E_1/2) of N-carbon decreases from 0.667 V to 0.636 V in 0.5 M H₂SO₄. Loading of CoSe₂ enhances the activity of N-carbon, when the samples were synthesized above 385 °C and formulated with the Se/Co ratio higher than 10. The higher activity is attributed to the pyrite phase of CoSe₂. But the stability of pyrite CoSe₂ is less than that of N-carbon. Corrosion during the stability test exposes the active sites of underlying N-carbon, which sustains the catalyst activity. Consequently the E_1/2 value of the active CoSe₂/N-carbon decreases moderately, from 0.711 V to 0.644 V after 1000 CV cycles. In contrast, the E_1/2 value of CoSe₂/C descends much more, from 0.681 V to 0.475 V.     

高效液相色谱法测定酱腌菜中脱氢乙酸含量的不确定度评定

目的 对酱腌菜中的脱氢乙酸含量进行测定并进行不确定度评定。方法 根据GB 5009.121-2016《食品安全国家标准 食品中脱氢乙酸的测定》中第二法液相色谱法,通过通过建立数学模型,识别测量过程中的各个不确定度来源,并对其进行分析和评定。结果 当添加水平为50 μg/mL时,酱腌菜中脱氢乙酸含量的测定结果为0.523 g/kg,在95%的置信区间下,其扩展不确定度为0.098 g/kg（k=2）。结论 对于高效液相色谱法测定酱腌菜中脱氢乙酸含量,其不确定度主要由配制标准溶液与拟合标准曲线构成。     

Dissolution of D2EHPA in liquid-liquid extraction process: implication on metal removal and organic content of the treated water

Effects of pH, extractant/diluent ratios, and metal concentrations on the extent of extractant dissolution during liquid-liquid extraction were investigated. Experimental result shows that D₂EHPA dissolution increases dramatically at pH above 4, leveling off at pH 6-7. The phenomenon is consistent with deprotonation of D₂EHPA and the domination of negatively charged D₂EHPA species at pH of higher than 4. Concentration of D₂EHPA in the aqueous phase, i.e., the extent of extractant dissolution, drops after addition of metal and decreases with increasing metal concentration. The amount of D₂EHPA ‘re-entering’ the organic phase is calculated to be 2.04 mol per mol of Cd added, which is quite closed to the stoichiometric molar ratio of 2 between D₂EHPA and Cd via ion exchange reaction. The effect of metal species on the extent of extractant/metal complexes re-entering is in the order of Cd≈Zn ＞ Ag, which might be coincident to the complexation stability of these metals with D₂EHPA. The extent of extractant dissolution in liquid-liquid extraction process depends on the type and concentration of metal to be removed, pH of aqueous phase, and extractant/diluent ratios.     

Field emission properties of RuO2 thin film coated on carbon nanotubes

Carbon nanotubes (CNTs) have been widely applied in field emission (FE) due to their high geometric aspect ratio and low work function. More recently, researchers have introduced ruthenium dioxide (RuO₂) as a field emitter because of its excellent chemical and thermal stability due to its oxide nature. This study used the surface morphology of CNTs and the field emission (FE) stability of RuO₂ to improve FE characteristics. Since the work functions of CNTs and RuO₂ are very close, this study combined these two elements by applying a thin film of RuO₂ on the CNT surface. In the process of covering the tips of CNTs with a thin film of RuO₂ eventually obtained the best matching of these two elements. The study not only enhanced the FE performance of CNTs but also extended FE lifetime by applying a thin film of RuO₂ on the CNT tips.     

EMBEDDING AN EXPONENTIAL FUNCTION IN A TWO-BOUNDARY GRID GENERATION TECHNIQUE FOR THE TURBULENT HEAT TRANSFER IN A PISTON-CYLINDER SYSTEM

An algorithm for a multidimensional numerical solution is developed to calculate the turbulent flow field and heat flux in a piston-cylinder system. The two-boundary grid generation technique is used to transfer a rectangular computational plane into the physical domain of a piston-cylinder system for each simulation time step with a connecting function, which may be a linear function or a cubic polynomial with/without an exponential function embedded. Hence, the Jacobian matrix can be obtained by direct analytic differentiation, and less computation time is required for the solution. It is found that the technique of embedding an exponential function in a cubic polynomial function is the most efficient of the four generation techniques mentioned above. Comparison is made between the present results and other earlier results. The computational algorithm in the present study can successfully calculate the turbulent flow field and wall heat flux in a piston-cylinder system on a commercial personal computer.