基于R型聚类-因子分析的指标体系简化方法

评价指标体系过于复杂,容易产生冗余信息,增加计算与分析的难度.本文针对评价指标体系的简化方法展开研究,提出了基于R型聚类-因子分析的代表元提取方法.该方法具有定量控制代表元的信息丢失率、代表元实际含义易于解释等优点,同时避免了因子分析难以处理独立指标的问题.实验结果表明本文所提出的R型聚类–因子分析指标体系简化方法可以在没有先验知识可用的情况下,有效提高指标体系的简明性与有效性,同时保持指标信息的完备性.     

基于RS、GIS集成的水深探测研究

利用陆地卫星TM影像反射率和实测水深值之间的相关性,建立了遥感信息与水深之间的非线性回归模型.给出了遥感图像去噪算法.在此基础上设计了一个基于GIS组件MapX,采用C/S架构,使用VB和Microsoft SQLServer 数据库相结合的集成系统,实现了水深探测的可视化以及水深信息的查询和管理功能.实验结果表明,改进模型预测精度高,系统具有可视化、集成化和可扩展性强等特点,能够满足水深探测研究的需要.     

Texture analysis of poly-adenylated mRNA staining following global brain ischemia and reperfusion

Texture analysis provides a means to quantify complex changes in microscope images. We previously showed that cytoplasmic poly-adenylated mRNAs form mRNA granules in post-ischemic neurons and that these granules correlated with protein synthesis inhibition and hence cell death. Here we utilized the texture analysis software MaZda to quantify mRNA granules in photomicrographs of the pyramidal cell layer of rat hippocampal region CA3 around 1 h of reperfusion after 10 min of normothermic global cerebral ischemia. At 1 h reperfusion, we observed variations in the texture of mRNA granules amongst samples that were readily quantified by texture analysis. Individual sample variation was consistent with the interpretation that animal-to-animal variations in mRNA granules reflected the time-course of mRNA granule formation. We also used texture analysis to quantify the effect of cycloheximide, given either before or after brain ischemia, on mRNA granules. If administered before ischemia, cycloheximide inhibited mRNA granule formation, but if administered after ischemia did not prevent mRNA granulation, indicating mRNA granule formation is dependent on dissociation of polysomes. We conclude that texture analysis is an effective means for quantifying the complex morphological changes induced in neurons by brain ischemia and reperfusion.     

R/S分析法在大坝安全监测中的应用

R/S分析法可以描述自然界非线性系统的某种复杂性。以某水电站大坝坝顶水平位移为研究对象,采用R/S分析法得到其测点水平位移序列的Hurst指数,并根据Hurst指数在不同区间表现出的不同特性,分析坝顶未来的变化趋势。结果表明:该测点未来位移有较明显的增加趋势,应加强监测,以确保未来大坝的安全运营。     

直方图的脑图像分割策略

为了提高核磁共振分割精度和效率,提出了一种基于直方图核磁共振脑图像分割算法.利用脑提取工具剔除脑核磁共振图像中非脑组织.根据灰度变化的特点,将脑图像直方图的区域峰值组成新的直方图,通过基于直方图阈值选取规则将脑组织分割成白质、灰质、脑脊液.实验结果表明:该算法相对于常见的分割算法,获得了较高的分割精度,同时运算效率高,运算时间降低了1~2个数量级.     

The "hidden observer" phenomenon in hypnosis: Some additional findings.

23 highly hypnotizable undergraduates (Harvard Group Scale of Hypnotic Susceptibility) underwent 2 specially constructed 7-item hypnotic inductions. Over the 14 items, the main finding was of a relationship between E. R. Hilgard's (1973, 1977, 1979) "hidden observer" effect and 2 aspects of hypnotic age regression. Ss reporting a hidden observer experienced duality during regression to age 5, in which they were aware of being both adult and child. When asked to write a complex sentence, most did so, usually without spelling errors. The Ss not reporting this effect experienced quasi-lateral age regression in which they had the exclusive feeling of being 5 yrs old, with no sense of an adult identity. Most of these Ss were unable to write the same complex sentence when requested to during age regression. The study replicated Hilgard's finding of the hidden observer phenomenon in terms of its incidence and obtained similar verbal reports from Ss experiencing it. At the same time, the results suggest that a neodissociation account of hypnosis may need some modifications to accommodate these additional findings. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Determination of J–R curves of thermoplastic starch composites containing crossed quasi-unidirectional flax fiber reinforcement

Thermoplastic starch (MaterBi) composites reinforced with quasi-unidirectional flax fiber in cross-ply (CP) arrangement were produced by film stacking followed by hot pressing. These composites, containing various amount of flax, failed ductilely with pronounced crack growth. Therefore, to determine their fracture mechanical behaviour the J-integral resistance curve concept (J–R) was applied. As the crack growth could not be traced, attempt was made to use the located acoustic emission (AE) events for that purpose. It was established that weighting and smoothing the located cumulative AE amplitudes the crack path can be correctly reconstructed. This was proved by collating the AE results with those derived from infrared thermographic (IT) inspection. Knowing the crack propagation at each point of the force–displacement curves the J–R curves could be determined. Both critical or initiation J-integral and tearing modulus went through a minimum with increase of flax content in the composites.     

Viscosity of Alternative Refrigerants R407C and R407E in the Vapor Phase from 298.15 to 423.15 K

This paper presents new measurements of the viscosity of gaseous R407C (23 mass% HFC-32, 25 mass% HFC-125, 52 mass% HFC-143a) and R407E (25 mass% HFC-32, 15 mass% HFC-125, 60 mass% HFC-143a). The measurements were carried out with an oscillating-disk viscometer of the Maxwell type at temperatures from 298.15 to 423.15 K. The densities of these two fluid mixtures were calculated with the equation-of-state model in REFPROP. The viscosity at normal pressures was analyzed with the extended law of corresponding states developed by Kestin et al., and the scaling parameters needed in the analysis were obtained from our previous studies for the viscosity of the binary mixtures consisting of HFC-32, HFC-125, and HFC-134a. The modified Enskog theory developed by Vesovic and Wakeham (V-W method) was applied to predict the viscosity for the ternary gaseous HFC mixtures under pressure. As for the calculation of pseudo-radial distribution functions in mixtures, a method based on the equation of state for hard-sphere fluid mixtures proposed by Carnahan-Starling was applied. It was found that the V-W method can predict the viscosity of R407C and R407E without any additional parameters for the ternary mixture.     

高压开关柜隔离触头温度监测研究

针对高压开关柜的高压、强磁场工作环境，提出了基于光纤光栅传感器的隔离触头温度测量方案，实现了高压开关柜的触头温度监测。在方案中提出了空分和波分复用的光路系统，同时采用合理的安装技术解决了应变交叉敏感的影响，通过实验建立了隔离触头温度测量模型。在突然掉电的方式下对系统的抗电磁干扰能力进行了定性分析，测量显示温度曲线是渐变而不是突变的，说明系统具有很强的抗电磁干扰能力。通过对全天温度数据监测，系统能够正常工作，说明方案是可行的。     

1000 MW机组高压厂用电电压等级优化

针对1 000 MW机组高压厂用电系统短路电流增大和大电动机启动困难等诸多问题,分析了选择高压厂用电电压须考虑的几个因素。经过对各方案选择、论述及比较,选择10 kV 1个电压等级方案。10 kV小容量电机与其他两个方案的电机相比除损耗及体积略大外,在总投资方面基本与选择第2个方案持平,此外,电厂的运行管理均优于其他两个方案,因此,推荐采用10 kV 1个电压等级。