简述动力中心主厂房和输煤系统的建筑设计

笔者通过工程实践介绍了锅炉及发电装置主厂房和输煤系统的建筑设计特点,主要涉及平面设计、安全疏散、采取的防火以及建筑外观设计,力图为相关工程设计提供有益参考。     

Optimization of the technological properties of porcelain tile bodies containing rice straw ash using the design of experiments methodology

This study examines the effects of replacing fluxing and filler materials with rice straw ash (RSA) in manufacturing porcelain stoneware tile, using the design of experiments (DOE) methodology. The results of the characterization were used to obtain statistically significant, valid regression equations, relating the technological properties of the dried and fired test pieces to the raw materials content in the unfired mixtures. The regression models were analysed in relation to the X-ray diffraction and scanning electron microscopy results and used to determine the most appropriate combinations of traditional raw materials and RSA to produce porcelain stoneware tiles with specific technological properties. The studied range of tile body compositions: clay (40 wt%), feldspar (20–50 wt%), feldspathic sand (5–20 wt%), and RSA (0–25 wt%) was shown to be appropriate for porcelain stoneware tile manufacture.     

余热回用在轮胎制造行业的具体实践Reuse of waste heat in the concrete practice of tire production 李鹏,赵兰春,李靖

科学合理、充分高效的回收利用轮胎制造过程中所附生的高品位余热资源,不仅是降低轮胎制造过程能源成本的重要途径和方法,也是有效减少大气污染物排放量的可靠保障,对于实现企业自身经济效益的提高并最终实现资源、环境、经济、社会的协调发展具有重要战略意义。     

一种完全基于圆弧与直线的液力变矩器三维流线设计法

为降低流线曲率所造成的能量损失、提高液力变矩器的效率,提出了一种全新的设计方法——完全基于圆弧与直线的液力变矩器三维流线设计法.推导了三维流线方程和数值计算公式,开发了相关程序,验证了该设计方法的可行性.研究结果表明完全基于圆弧与直线的液力变矩器三维流线设计法具有下列优点:第一,三维流线的曲率半径达到最大且保持不变,这就大大降低了流线曲率所造成的能量损失;第二,由于内环侧的流线曲率半径较小,出口段设计成一段直线,有利于降低出流偏离角,可以降低出流偏离造成的能量损失.因此,在其它条件不变的情况下采用该方法设计的液力变矩器效率可以达到最大值.此外,按照该方法设计的叶片弯扭程度比较小,且叶片仅有二维曲率,便于制造.     

YB32-200型压力机液压系统节能设计

环境恶化和能源危机使得在工程技术领域内,以"节能"、"环保"为特征的绿色液压技术得到推广和应用。材料成型设备YB32-200型压力机应用广泛,从节能角度对原有液压系统进行节能改造,利用蓄能器回收主液压缸无杠腔的高压能量,并应用西门子200PLC代替原有继电器控制,使压力机更加节能、工艺动作更准确、可控性更高。     

Analyzing the surface layer after WEDM depending on the parameters of a machine for the 16MnCr5 steel

The efficient wire electric discharge machining (WEDM) technology is a trade-off between the cutting speed and the resulting surface quality. A typical morphology of a surface machined using WEDM contains a large number of craters caused by the electric sparks generated in the cutting process. The paper analyzes the influence of the cutting speed on the quantitative and qualitative evaluation of the craters formed on the surface of a workpiece made of the 16MnCr5 steel. Applying metallography to cross-section microscopic slides, diffusion subsurface damages were studied caused by the cutting. The diffusion processes taking place between the electrode and the material machined were studied using a local point EDX microanalysis applied both to the machined surfaces and to the cross sections. A detailed study was also carried out of the brass electrode to measure its wear rate caused by the cutting process as well as its degradation in terms of the quality of its morphology and the chemical composition of surface.     

Building urban resilience with nature-based solutions: How can urban planning contribute?

Cities face increasing environmental, social and economic challenges that together threaten the resilience of urban areas and the residents who live and work there. These challenges include chronic stresses and acute shocks, amplified by climate change impacts. Nature-based solutions have emerged as a concept for integrating ecosystem-based approaches to address a range of societal challenges. Nature-based solutions directly address and contribute to increased urban resilience. However, implementing nature-based solutions is inherently complex, given the range of ecosystem services, their multi-functionality and the trade-offs between functions, and across temporal and spatial scales. Urban planning can play a substantial role to support the implementation of nature-based solutions and to manage trade-offs and conflicts, as well as how social equity dimensions are considered. This paper presents a framework that guides the application of urban planning to nature-based solutions’ implementation, by addressing key trade-offs across temporal, spatial, functional and social equity aspects. The framework highlights the key questions, and the supporting information required to address these questions, to underpin the inclusion of nature-based solutions for urban resilience. We find that while urban planning can contribute substantially, there are continuing gaps in how the inherently anthropocentric urban planning processes can give voice to non-human nature.     

A novel paradigm for managing the product development process utilising blockchain technology principles

The product conceptualisation, design and manufacturing phases are becoming increasingly complex, since more available resources, stakeholders and sophisticated technologies are involved during product development. The exchange and management of product-related information is often a challenging task, affecting significantly the intellectual property protection process as well as the distinction of roles among stakeholders. This paper proposes a conceptual framework that utilises blockchain technology principles for managing product development information and processes with the goal of providing new approaches to extending the functionality of product data management systems. A test case focusing on products developed with additive manufacturing technologies is presented.     

Allocation of assembly tolerances to minimize costs

The cost and quality of an assembly depend on the processes used to manufacture its components. The specific processes and process settings are often dictated by the tolerances on the components. One long-standing challenge is allocating the assembly tolerance to components. Many methods have been proposed, most of which endeavor to minimize cost. We propose a tolerance allocation method that minimizes cost by jointly considering process variation and tolerance specifications. A cost model including processing cost, scrap cost, and quality loss is employed. The cost is minimized by a heuristic strategy. An overrunning clutch assembly case study is used to evaluate the method.     

北岳职业技术学院校园网建立及应用状况

论述了校园网设计与建设过程中确立建设校园网的目标，校园网的技术方案设计，信息资源建设，应用软件的开发，网络管理与安全等5个方面的问题。