子模型方法在白车身强度计算中的研究

介绍了子模型技术在白车身强度分析中的应用。以白车身手刹底座上板的强度分析及优化设计为例,讨论了子模型技术的基本原理及使用方法。子模型技术在有限元分析中具有准确性、便捷性、快速性等优势。     

Building as Interface: or,What Architects Can Learn from Interaction Designers

Walter Aprile and Stefano Mirti have been engaged as designers, researchers and teachers at Interaction-Ivrea, a technological research institute in northern Italy, since it was established by Telecom Italia and Olivetti in 2001. Here, the two reflect on the series of experiments they have undertaken at the intersection of interactive technology and architecture, analysing their own working systems and the means by which they have chosen to pursue interdisciplinary dialogue. Copyright © 2005 John Wiley & Sons, Ltd.     

测定回收灰质量的煅烧仪工作原理及其应用

在苛化沉降物白泥（主要成分ＣａＣＯ３）转化为生石灰（主要成份ＣａＯ）的过程中,ＣａＣＯ３的含量在不断地减少。当碳酸钙含量在１５％～３０％时,说明石灰炉燃烧正常,且回收灰质量合格。利用煅烧仪可以测定回收灰中碳酸钙的含量。该文介绍了煅烧仪的工作原理及其应用。     

基于白盒化技术的配电站监控系统的应用

针对配电站监控系统对厂站设备适配和监控系统迭代升级的需求,提出了一种应用白盒化嵌入式系统技术的方案。该方案采用白盒化开放接口设计,制定统一规范接口,并在程序软件设计上采用协议库动态管理的方法,从而实现了监控系统的灵活管理,同时显著降低了建网和后期维护成本,有效提高了配电站监管平台开发和运行的可靠性。     

Effects of sodium and potassium fertilisers on the composition of herbage and its acceptability to dairy cows

Fertilisation of herbage with Na can increase acceptability to cows, but the influence of fertiliser rate and fertilisation by K is unknown. In experiment 1, ten cows were grazed on pasture plots that had just been fertilised with 0–132 kg-Na ha⁻¹ (current Na) and had received 0–64 kg-Na ha⁻¹ in the previous grazing season (residual Na). Herbage Na concentration increased in proportion to current Na from 2·7 to 4·9 g-Na kg⁻¹ dry matter (DM) and also increased with increasing residual Na from 2·2 to 4·5 g-Na kg⁻¹ DM. Herbage K concentrations were low (10 g kg⁻¹ DM at 0 kg-Na ha⁻¹) and were only slightly reduced by Na fertiliser. Herbage Mg and Ca concentrations and DM digestibility were maximum at 66–99 kg-current-Na ha⁻¹. Cows grazed current-Na-fertilised plots to a lower height and spent more time grazing them. In experiment 2, pasture plots received no fertiliser, low and high isomolar and independent applications of Na and K or a combination of the two. The herbage was more mature than in experiment 1 and Na concentration of the herbage without Na fertilizer was high (5 g kg⁻¹ DM). Na fertiliser, therefore, only slightly increased Na concentration, more in clover than in grass, and had little effect on K concentration. K fertiliser increased K concentration from 16 to 20 g kg⁻¹ DM and reduced Na concentration to 3·5 g kg⁻¹ DM. Sodium fertiliser, therefore, only increased the acceptability of herbage to cattle when herbage Na concentrations were initially low (less than 5 g kg⁻¹ DM) and were increased substantially by the application of the fertiliser. © 1998 SCI.     

Delay-independent stability of moments of a linear oscillator with delayed state feedback and parametric white noise

The stability of a linear oscillator with delayed state feedback driven by parametric Gaussian white noise is studied in this paper. The first and second order moment equations of the system response are derived by using moment method and Itô differential rule. Based on the moment equations, the delay-independent stable conditions of both moments are proposed: For the first order moment, the sufficient and necessary condition that guarantee delay-independent stability is identified to that of the deterministic system; for the second order moment, the sufficient condition that ensure delay-independent stability depends on noise intensity. The theoretical results are also illustrated with numerical simulations.     

某核电厂反应堆换料水池不锈钢覆面钢板白斑分析

对国内某核电厂反应堆换料水池不锈钢覆面的白斑现象进行了分析和模拟试验,结果表明不锈钢覆面钢板白斑的产生原因为局部酸洗钝化时间过长,表面形成了不同程度的钝化膜。通过分析白斑对钢板组织和耐腐蚀性能的影响,对电厂后续相关工作提出了建议。     

Maximum temperature of smoke beneath ceiling in tunnel fire with vertical shafts

To assess the impact of heat smoke in tunnel with vertical shafts, the maximum temperature of smoke beneath ceiling is researched theoretically and experimentally in this paper. A theoretical prediction model for maximum temperature of smoke beneath ceiling is built using dimensional analysis. A numerical model is built and calibrated with the full-scale experiment data. The calibrated numerical model is used to simulate the maximum temperature of smoke under different conditions with different shaft geometry. At last, the proposed theoretical model was formulated and compared with Kurioka model, experimental data and simulation data. The results show that the proposed theoretical model can give a better prediction for the tendency. It can be used to predict the maximum temperature of smoke beneath ceiling of tunnel with vertical shafts by taking the shaft geometry and arrangements effect into account.     

稀土白口铸铁衬板类零件的生产工艺

共晶碳化物呈连续网状分布是白口铁脆性的根源。运用稀土变质处理和热处理相结合的方法可以使共晶体碳化物断网、团聚化的原因在于变质处理后形成的有利的铸态组织更能籍助热力学与动力学规律,实现“小粒溶解,大粒团聚”。再加上充分奥氏体化后的二次碳化物弥散析出分布,白口铁性能得到了根本的改善。用它来制造衬板类零件,材料特性符合工况使用条件,其耐磨性约达高锰钢的２倍以上。