Properties and Application of Double Alkali Earth Doped Ce0.9Ca0. 1 - xSrxO1.90

A series of solid solution material based on ceria, Ceo.9Cao.l-xSrsOi.90(x = 0, 0.04, 0.05, 0.06), were synthesized by a solid reaction method. Ceria doped with two alkali earth dements has cubic fluorite structure. The ionic conductivity of these materials at high temperature was studied by impedance spectra, and an increasing effect of ionic conductivity was found. A maximum conductivity is achievedwhen the effective ionic radius is near to the critical radius (0. 1106 nm). Some fuel cells were made using these materials as electrolyte. The output power and current of the SOFC with the electrolyte of double doped ceria are better than those of YSZ and single doped ceria, and the open-circuit-voltage of the double doped ceria is also higher than that of the single doped ones.     

煤矿人员定位系统拓扑优化模型

对煤矿巷道网络进行建模,提出一种基于无线传感器网络的层次式煤矿人员定位系统,并对人员定位系统成本进行分析,设计出包括测点代价和测点之间线缆代价的优化目标函数。推理结果表明,该成本优化问题与煤矿传感器节点间路径优化问题相一致。最后应用Prim算法对人员定位系统拓扑结构进行优化,结果验证了优化模型和算法的有效性。     

同轴馈电耦合微带天线的MPSTD-FDTD分析

将多区域时域伪谱(MPSTD)与时域有限差分(FDTD)相结合的混合算法应用于同轴馈电耦合微带天线的分析,该混合算法充分发挥两种时域算法的优越性,对同轴馈电耦合微带天线进行了准确建模与快速分析,数值仿真验证了该算法的有效性和准确性。     

自吸背景校正石墨炉原子吸收法测定全血中的铅

铅是一种蓄积性的有毒物质,过量铅的摄入严重影响人的身心健康。血铅是作为职业性铅中毒和职业性健康检查的必检项目。文章用专用试剂直接稀释样品,无需在标准溶液中加入健康人血做基体匹配,自吸背景校正石墨炉原子吸收法直接测定全血中的铅,方法的精密度为2.34%～5.45%,回收率为107%,检出限为0.98μg/L,获得了满意的...     

浙江省遂昌县玉兰资源现状与保护对策研究

以浙江遂昌县为调查对象,分析其野生玉兰分布状况、生长现状及生境特征。结果表明,该地区野生玉兰植物资源较少,但玉兰古树有39株,说明遂昌具有悠久的玉兰种植历史;由于森林抚育、人为破坏等原因,森林范围内未见野生玉兰幼年树,且接近人居的玉兰古树未得到更好的保护。分析了遂昌县玉兰资源的保护现状,并针对现状问题,提出了建议性保护措施,为玉兰资源保护与利用奠定基础。     

露天矿采装环节粉尘运移规律与降尘技术研究

以国内某大型露天煤矿岩石采装环节为研究对象,根据欧拉-拉格朗日研究方法,利用FLUENT模拟分析软件对采场工作面P&H4100XPC重型矿用电铲铲装物料并落料于矿用自卸卡车箱斗时产生的粉尘运移规律进行数值模拟,与现场监测结果对比,验证模型正确性。结果表明：电铲落料产生81.4%粉尘积聚在电铲附近,下风向1 m处粉尘质量浓度最高为42.87 mg/m³;在高度13 m处粉尘浓度最高为4.51 mg/m³,高度方向38 s时粉尘浓度低于环境空气质量二级标准;进一步模拟雾炮车等降尘技术极其效果比较,认为雾炮车喷雾器装置布设在下风向20 m处、垂直角度控制在45°～55°,可以有效地降低采装作业粉尘的扩散。     

Optimizing light delivery in scanning photoacoustic imaging for prostate

The purpose of this study was to optimize the light delivery method in a prostate photoacoustic imaging system. A three dimensional(3D) optical model of the human prostate was developed, and the optical energy distribution in the prostate was estimated via three-dimensional Monte Carlo simulation. Then, the feasibility of prostate photoacoustic imaging(PAI) using two endoscopic light delivery methods was studied. Photoacoustic pressure generation and the corresponding photoacoustic images had been obtained and the comparisons were made between each other. Also, the results of cylinder diffusing light source with different lengths were compared. After that, phantom experiment was carried out to validate the simulation results. Our results would be significant in the optimizing photoacoustic imaging system for an accurate diagnosis of prostate cancer.     

300MW汽轮发电机组振动故障分析与处理

某厂4号汽轮发电机组(300MW)在调试期间先后出现了主汽门严密性试验时的突发性非稳定高幅振动及带负荷后的稳定性偏高振动。根据对振动测试的分析结果、相关设备检查以及现场解体检修,发现发电机密封瓦突发性的碰磨及轴颈处钢字码是造成2种截然不同的振动现象的根本原因,通过解决机组振动问题,使机组振动达到优良标准。     

自吸效应背景校正原子吸收技术的发展及应用

利用空心阴极灯的自吸效应校正背景吸收的技术在1980年前后被提出,这一技术不需要附加的任何设备,仅通过在空心阴极灯上施加强、弱电流即可实现背景校正。经过近30年的发展,国内外都能生产商品化的自吸扣背景原子吸收光谱仪器,同时,已有一些关于自吸背景校正方法的具体应用实例。本文对自吸效应背景校正原子吸收技术与仪器的发展及应用作一综述。     

废弃ACQ防腐木苯酚液化物合成酚醛树脂的研究

利用废弃ACQ防腐杉木苯酚液化物与甲醛在碱性环境中反应,进行热固型酚醛树脂合成实验;通过正交试验方法研究了单因素变量对树脂化反应的影响。得出最优化的树脂化合成工艺为:合成温度80℃,合成时间120min,氢氧化钠/液化物摩尔比(mrNaOH/P)=0.6,甲醛/液化物摩尔比(mrF/P)=2.0。在此工艺条件下制备的酚醛树脂压制的胶合板胶合强度达到1.33MPa,符合GB/T17657-1999中Ⅰ类胶合板的强度要求。