城市设计实践中的生态学方法初探

本文试图探讨将区域性生态规划理论及其方法应用于城市尺度的课题,初步探索了生态学在城市设计过程中实际应用的可能性。在简要介绍生态理念及生态科学在规划中被应用的发展历史之后,简述“千层饼法”、AHP权重计算法和因子组合法等在“垂直生态过程”的量化分析中的作用。此后通过景观生态学的“斑块-廊道-基底”模式和相关的经验性规则试图解决“水平生态过程”中的相关问题,提出了在城市尺度上建立“生态优先”的“生态安全格局”的构想。     

Cr含量对2Cr13轴套的组织与力学性能的影响

介绍了 Cr含量不同的两件 2 Cr13轴套经同样热处理后力学性能与组织的差异。结果表明 :Cr含量是影响 2 Cr13轴套组织与力学性能的关键因素。     

8m×6m风洞动力系统运行20年

本文主要介绍了 ８ ｍ×６ ｍ风洞动力系统的组成,２０年来的运行情况以及对系统的评价等。     

基于RBF神经网络的转炉炼钢终点预报

转炉炼钢终点温度和成分是转炉炼钢的控制目标, 它与吹氧量、铁水加入量等多个变量之间存在着严重的非线性关系, 且无法在线连续测量。作者提出了基于ＲＢＦ 神经网络的转炉炼钢终点温度及碳含量预报模型, 并结合某钢铁企业一座１８０ｔ 转炉的实际数据进行模型验证研究。结果表明, 该方法收敛速度快, 预报精度高。     

煤沥青热聚合改质研究

在热聚合反应釜中 ,研究了煤沥青中甲苯不溶物、喹啉不溶物、β树脂、软化点及结焦值等质量指标在热聚合改质过程中的变化规律 .实验结果表明 ,在热聚合过程中 ,煤沥青中甲苯不溶物、喹啉不溶物、软化点及结焦值等指标均随聚合温度升高和聚合时间延长都有变化性增加 ,而β树脂在实验条件下 ,开始随聚合温度升高和聚合时间延长 ,到一定值后 ,再提高温度 ,或延长时间则下降 ,存在一极大值区间 ,该结果得到重复性实验的确认 .结果显示 ,改质沥青的主要质量指标波动范围很小 ,可为今后的放大实验或工业生产提供重要依据 .     

膜本身性质对MBR膜污染影响研究进展

膜生物反应器出水水质稳定、占地小,是目前水处理的研究热点之一。但膜污染问题是阻碍该工艺发展的重要致因。其中膜本身性质是其关键影响因素。本文总结了膜本身性质对膜污染的影响研究进展,以期为推广该工艺的发展创造条件。     

Prediction‐based MAC‐layer sensing in cognitive radio networks

We consider a cognitive radio network which coexists with multiple primary users (PUs) and secondary users (SUs) transmit over time‐varying channels. In this scenario, one problem of the existing work is the poor performances of throughput and fairness due to variances of SUs' channel conditions and PUs' traffic patterns. To solve this problem, we propose a novel prediction‐based MAC‐layer sensing algorithm. In the proposed algorithm, the SUs' channel quality information and the probability of the licensed channel being idle are predicted. Through the earlier predicted information, we schedule the SUs to sense and transmit on different licensed channels. Specifically, multiple significant factors, including network throughput and fairness, are jointly considered in the proposed algorithm. Then, we formulate the prediction‐based sensing scheduling problem as an optimization problem and solve it with the Hungarian algorithm in polynomial time. Simulation results show that the proposed prediction‐based sensing scheduling algorithm could achieve a good tradeoff between network throughput and fairness among SUs. Copyright © 2014 John Wiley & Sons, Ltd.     

厌氧氨氧化研究进展及其应用

该文综述了厌氧氨氧化的机理、微生物基础和反应的影响因素,并介绍了厌氧氨氧化在废水生物脱氮方面的应用前景。着重提出了厌氧氨氧化在污泥颗粒化技术中的实现的可能机理。     

呼唤开放式建筑教育体制

改革开放２０多年 ,我国的建筑教育事业有了很大的发展 ,基本上适应了我国经济发展的需要。新世纪即将来临 ,我国的经济和科技发展将跃上新的台阶 ,并融入世界经济体系之中。未来经济和科技的竞争实际上是人才之争 ,它对我们的建筑教育提出了更新更高的要求。科教兴国的战略决策要求我们必须争创国际一流。为此 ,创立开放式的建筑教育体制就显得十分迫切。我想到了这么几条 :开放的办学思想最重要的是从国情出发、实事求是、解放思想、转变观念。在国际上我们要办出中国特色 ,用特色去接轨。在国内我们要办出地方特色 ,用特色去占有一席之地…     

Viscosity variations of coal-oil slurry under high temperature and high pressure during heating process

Heating coal-oil slurry (COSL) is an important step in direct coal liquefaction. Some physical and chemical properties of COSL including its viscosity will change during heating. A rotary viscometer was self-designed to measure the viscosity of COSL under high pressure and temperature. Three kinds of coal, which are Yanzhou coal (middle rank and caking), Shenhua coal (low rank and non-caking) and Shengli coal (brown coal), were mixed with anthracene oil to prepare the COSL. The COSL from Yanzhou, Shenhua and Shengli at the same experimental conditions showed different viscosity variations under high hydrogen pressure during heating. Yanzhou COSL had a higher viscosity peak, while Shenhua COSL had two small viscosity peaks and in the case of Shengli COSL, no viscosity peak was present under a high hydrogen pressure during the whole heating process. The coal nature is the important factor of viscosity variations of COSL. The higher the coal rank, the more caking coal is present, and the more obvious the viscosity variations of the COSL are.