B2O3对CaO基渣精炼的助熔作用和脱硫的影响

使用RTW-08熔体物性测定仪通过旋转粘度计法测定了熔渣的粘度.试验结果表明,B2O3和CaF2在46%CaO-10%BaO-11.2%SiO2-11.6%Al2O3基础渣系中的助熔效果相当;在CaO-SiO2-10%BaO-11.6%Al2O3-10%CaF2基渣的碱度(CaO+BaO)/(SiO2+B2O3)为2.5和2.8时,用B2O3替代1/4 SiO2后精炼渣高温熔化性能稳定,粘度值降低至0.3～0.5 Pa·s;碱度2.8时,含20.6%SiO2渣剂的脱硫率为85%(S含量由0.008%降至0.001 6%),而含10.3%SiO2-10.3%B2O3渣剂的脱硫率为91.3%(S含量由0.008%降至0.000 7%).     

SBS改性效果对基质沥青的依赖关系

SBS加入沥青后可以改善沥青的使用性能,SBS对基质沥青的改性效果与基质沥青的组成和性质有直接关系。首先以沙中减渣调合得到的沥青为基质沥青,加入不同量的SBS,考察了SBS对改性后沥青各个指标的影响,发现SBS可以使沥青针入度降低,软化点升高,低温延度(5℃)增加,抗老化性能增强,并从机理上对其进行了阐述。同时又以4种不同减渣经调和制得符合GB/T15180-94标准的AH-110的沥青为基质沥青,以胶体不稳定指数Ic为参数讨论了加入相同量SBS对不同基质沥青的改性效果,发现Ic越小,针入度、软化点、低温延度(5℃)、粘度(60℃)的变化程度越大。同时发现基质沥青的老化指数越高,SBS对其抗老化性能改善越显著。     

异步起动钕铁硼永磁同步电动机的设计研究

在讨论了异步起动钕铁硼永磁同步电动机设计特点基础上，编制了该种电机设计软件，设计与试制了Nd-FeB永磁同步电动机，同时也提出了该种电机的合理应用场合。     

增强现实中基于位置安全性的LBS位置隐私保护方法

为了解决基于位置的服务(LBS)和增强现实(AR)技术快速发展带来的用户位置隐私泄露的隐患,分析了现有的位置隐私保护方法的优缺点,提出基于位置安全性的位置隐私保护方法。将区域安全度和伪装区域引入该方法中,将提示某区域是否需要保护这一度量标准定义为区域安全度,非安全区域(即需要给予保护的区域)的区域安全度设置为1,安全区域(即不需要保护的区域)设置为0,通过扩大区域安全度和识别等级来计算位置安全度。实验结果表明,该方法与未引入位置安全性的方法相比降低了平均定位误差,提高了平均安全性,从而有效地保护了用户的位置隐私,提高了LBS的服务质量。     

Effect of hybridizing Biogeography-Based Optimization (BBO) technique with Artificial Immune Algorithm (AIA) and Ant Colony Optimization (ACO)

Hybridization in optimization methods plays a very vital role to make it effective and efficient. Different optimization methods have different search tendency and it is always required to experiment the effect of hybridizing different search tendency of the optimization algorithm with each other. This paper presents the effect of hybridizing Biogeography-Based Optimization (BBO) technique with Artificial Immune Algorithm (AIA) and Ant Colony Optimization (ACO) in two different ways. So, four different variants of hybrid BBO, viz. two variants of hybrid BBO with AIA and two with ACO, are developed and experimented in this paper. All the considered optimization techniques have altogether a different search tendency. The proposed hybrid method is tested on many benchmark problems and real life problems. Friedman test and Holm–Sidak test are performed to have the statistical validity of the results. Results show that proposed hybridization of BBO with ACO and AIA is effective over a wide range of problems. Moreover, the proposed hybridization is also effective over other proposed hybridization of BBO and different variants of BBO available in the literature.     

Realization of active power filter based on indirect current control algorithm using Xilinx system generator for harmonic elimination

Realization of active power filter with Model Based Design approach is presented in this paper. The approach adopts different modeling platforms as well as selection of proper hardware for step wise verification and testing. The active power filter model is developed using the Matlab/Simulink platform for single phase. The efficiency of the control algorithms such as synchronous detection method and indirect current control for active power filter is analyzed. Efficient control algorithm is developed by Xilinx system generator which is incorporated into Simulink as Xilinx tool box. Xilinx system generator provides a virtual platform for easy and effective design of the required system models in FPGA (field programmable gate array) design environments. Optimized automatic VHDL code is generated for the control algorithm which is simulated using ISE 13.2 for the generation of switching signals for the control of IGBTs of the active power filter. Suitable compensation signal is generated from the active power filter for the better elimination harmonics to improve the power quality. THD is reduced to a considered value which is able to satisfy the limits of the IEEE standard.     

Ti对Nb-20Si-5Al超高温合金性能的影响

采用放电等离子烧结法(SPS)制备了Nb-20Si-5Al-xTi(x=0,18,20,22,摩尔分数)超高温合金,研究了Ti加入量对Nb-20Si-5Al合金的室温断裂韧度和高温抗氧化性的影响。结果表明,随着Ti加入量的增加,超高温合金的相组成由Nbss、Nb₅Si₃和Al3Nb相转变成为Nbss、(Nb,Ti)5Si3和Ti相。Ti能明显改善Nb-20Si-5Al超高温合金的断裂韧度和高温抗氧化性能,随着Ti加入量的增加均先提高然后降低,在Ti加入量为20%时,合金断裂韧度最大,为7.41 MPa·m^1/2,相比未加Ti时提高了约56.9%,其高温氧化速率最低,为0.72×10^-4g²/(cm⁴·h)。添加Ti元素后,其氧化产物中出现Ti₂Nb₁₀O₂₉、TiNb₂O₇、TiO₂等,可以提高其氧化膜的致密性,从而提高高温抗氧化性能。     

实用主义代码70后中国建筑师之建筑数字观

文章指出,70后中国建筑师站在计算机带来的新技术变迁的时代前沿从电脑普及化到电脑计算化,首当其冲受到技术革命带来的设计方法和过程改变的洗礼,从而对数字设计具有敏锐触觉。70后受到的教育延续布扎体系,深悉建筑本质：几何形态、空间、质感,光线和建构。＂建房子＂的迫切需求让70后的数字时代的建筑观具有强烈实用主义的特征,这样的特征给在中国建筑实践和教育中崛起的70后带来了产生新建筑形态语言和思潮可能的机会。     

煤基均聚聚丙烯1100N与市场同类石油基产品链结构组成与性能对比分析研究

采用核磁共振仪、傅里叶红外光谱仪、热重分析仪、差示扫描量热仪和力学测试等手段,研究了煤基均聚聚丙烯1100N及对比牌号链结构等微观结构、结晶行为、热性能及力学性能等。结果表明,与市场石油基同类产品相比,煤基均聚聚丙烯1100N具有链结构缺陷低、等规度高、易结晶、耐热性能和刚性好的优势,但抗冲击性能略低于同类产品。     

粗糙集与决策树在城轨头型意象设计的应用

目的 为挖掘大众对产品造型意象认知的机理,提出了一种将粗糙集理论和决策树技术相结合的产品造型意象设计方法。方法 首先,在感性工学理论的基础上,获取产品造型设计要素和感性评价数据,并运用粗糙集理论来构建知识表达系统;其次,对决策表属性进行约减,保留贡献值较大的属性,删除冗余属性;最后,通过AAID算法计算得到各个设计要素的重要度排序,在此基础上构建决策树,并通过读树提取相关设计规则。结果 以地铁列车头型设计为例进行研究,得到了影响感性意象“前卫的-过时的”核心设计要素,通过决策树提取到9条设计规则,结果验证了该方法的适用性和有效性。结论 通过对粗糙集理论和决策树技术的探究和应用,提出了地铁列车头型设计思路。研究结论可为其他城市轨道交通工具的产品造型意象设计提供参考依据,丰富轨道交通工具领域的产品创新设计方法。