一种快速自助听力检查方法设计及实现

为解决当前听力缺陷人群不断增加,而专业听力检查设备昂贵、检查过程繁琐、需要专业操作人员协助完成等问题,设计并实现.种基于计算机的快速自助听力检查方法.通过该方法用户可以快速、独立完成纯音听力检查并了解自己的纯音听阈和听力损失情况.该听力检查方法具有操作简便、检查快速、硬件实现成本低等特点,适用于城乡社区,对于普及听力检查、提高人民生活质量具有重要意义.     

聚合物反应挤出技术

叙述了聚合物反应挤出的定义、优缺点、反应挤出设备及反应挤出的原理等;阐述了反应挤出的应用,并展望了反应挤出的发展趋势。     

磁通门传感器探头温度特性研究

磁通门传感器主要由磁探头与电路部分组成,其输出不仅随磁场变化,而且易受温度的影响。为了确定磁通门传感器磁探头在宽温度范围下的温度漂移情况,通过试验将探头置于-40℃~150℃的温度环境下,记录得到探头在宽温度范围下,其温度特性曲线近似为正比线性关系。分析认为,磁芯磁滞回线受热偏移与线圈漆包线随温度热胀冷缩是磁探头温漂的主要原因。本文提出选用低磁导率磁芯和高温漆包线绕制探头,并优选一致性较好的探头,采用最小二乘法对温度漂移结果进行拟合补偿,有效地消除了温度对磁探头的影响,提高了磁通门传感器的温度稳定性与应用的广泛性。     

NO<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> emission from incineration of organic liquid waste in a circulating fluidized bed

An incineration test of a toxic chemical organic waste liquid was conducted on a circulating fluidized bed (CFB) incinerator. The flue gas was measured online with the advanced SAE-19 flue gas analyzer. The effects of several factors, in terms of flow rate of waste liquid, ratio of waste liquid injected into dense bed of the CFB, excess air coefficient, the secondary air fraction and bed temperature on NO _x emissions, were verified. The experimental results show that NO emissions in flue gas increase with increase in the flow rate of the waste liquid injected into the bed or the excess air coefficient or the bed temperature and those decrease with increase in the ratio of waste liquid injected into the dense bed of the CFB or the secondary air fraction. During the test runs, NO _x concentration in flue gas met the national regulation on NO _x emissions due to suppressive effect of low temperature and staged combustion in CFB on NO _x formation. This paper was presented at the 6 ^th Korea-China Workshop on Clean Energy Technology held at Busan, Korea, July 4–7, 2006.     

CPE和ACR对PVC-U型材加工性能的影响

从抗冲改性机理、微观形态、加工性能、冲击性能及老化性能等方面对PVC-U冲击改性剂氯化聚乙烯(CPE)和丙烯酸酯类(ACR)进行比较,客观地分析了各自性能的优劣。     

Mathematical model for the pultrusion of blocked PU–UP matrix composites

The thermokinetic behavior of blocked polyurethane (PU)–unsaturated polyester (UP)–based composites during the pultrusion of glass‐fiber‐reinforced composites was investigated utilizing a mathematical model that accounted for the heat transfer and heat generation during curing. The equations of continuity and energy balance, coupled with a kinetic expression for the curing system, were solved using a finite difference method to calculate the temperature profiles and conversion profiles in the thickness direction in a rectangular pultrusion die. A kinetic model, dP/dt = A exp(?E/RT)P^m(1 ? P)ⁿ, was proposed to describe the curing behavior of a blocked PU–UP resin. Kinetic parameters for the model were obtained from dynamic differential scanning calorimetry scans using a multiple regression technique, which was able to predict the effects of processing parameters on the pultrusion. The effects of processing parameters including pulling speed, die wall temperature, and die thickness on the performance of the pultrusion also were evaluated. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1996–2002, 2003     

Characteristic modes and flow structure of non-premixed flame in humid-air combustion

An experimental study has been performed in order to determine the effect of humidity on the flow field and the flame stability limit in turbulent non-premixed flame. Two-dimensional Particle Image Velocimetry (PIV) measurements were made to quantify the velocity field, with and without steam injected. The results indicate the addition of steam decreases the recirculation flow and reduces the distance between the forward and aft stagnation points. The detailed stabilization regimes show that the critical fuel-to-air velocity ratios of the central fuel penetration in the humid air case are 16% to 22% lower, and the partially quenching limits are at least 25% lower. The decreased penetration limit is due to a reduction in momentum of the humid air. An analysis of flamelet concepts reveals that increased chemical reaction time leads to lower partially quenching limits in the humid air combustion.     

振动筛板槽中液滴分散动力学的研究——(Ⅱ)实验结果及Monte-Carlo模拟技术的应用

本文根据前文(I)报的理论分析,采用Monte-Carlo方法对实验数据进行模拟.液滴直径的测量采用照相法及透光法.所测得的液滴直径分布数据及平均液滴直径的数据,在微机上进行拟合归纳,得到了振动筛板槽中液滴直径分布模型及液滴平均直径的关联式.模型计算结果与实测值拟合较好.应用Monte-Carlo模拟技术对液滴破碎和凝聚这一随机过程进行了模拟及参数估计,得到了液滴破碎速率及凝聚速率参数.     

聚氯乙烯／蒙脱土复合材料的结构与性能研究

采用熔融共混法制备得到PVC／蒙脱土复合材料。通过X射线衍射和透射电镜对复合材料的结构进行了表征。研究了钠基蒙脱土和烷基季铵盐改性的有机蒙脱土对聚氯乙烯／蒙脱土复合材料的结构、加工热稳定性、光学性能、力学性能和结构流变性能的影响。     

一种基于聚类加权的文本特征生成算法

目前的文本特征生成算法一般采用加权的文本向量空间模型,该模型使用TF-IDF评价函数来计算单个特征的权值,这种算法生成的文本特征冗余度往往都比较高。针对这一问题,采用了一种基于聚类加权的文本特征生成算法,首先对特征候选集进行初始加权处理;然后通过语义和信息熵对特征进行进一步加权处理;最后使用特征聚类对冗余特征进行剔除。实验表明该算法比传统的TF-IDF算法的平均分类准确率高出5%左右。