一类非线性分形插值曲面的构造与性质

讨论了二元连续函数振幅与变差的性质,并构造了一类非线性多参数迭代函数系;证明了在一定条件下吸引子的唯一性和分形插值曲面的存在性,利用连续函数变差的性质研究了所构造的分形插值曲面的维数,并给出了此类分形插值曲面计盒维数的计算公式.     

开槽预应力闸墩应力集中特性研究

为了较好地分析开槽预应力闸墩槽附近的应力集中问题,采用有限元结构分析软件模拟了某大型水电站在施工期和运行期不同荷载组合作用下的受力情况。通过改变预留槽的位置及大小,分析闸墩的应力分布状况。最后,从弹性力学的角度,应用复变函数法对孔口附近的应力分布情况进行计算,并将变化规律与开槽预应力闸墩的应力集中情况进行了分析对比。研究结果表明,预应力闸墩因开槽而引起应力集中可以被充分利用,不仅可以提高预应力锚索的预压效果,还可以通过改善预压应力的传力路径,使其传到更为有效的部位。     

区域自识别医用观片灯控制系统设计

基于嵌入式控制技术,提出一种具有区域自识别功能的新型医用观片灯系统结构。该系统以超高亮白光LED构成分布均匀的LED阵列,通过嵌入式控制器识别X光片的规格及覆盖区域,并控制该区域的LED灯阵列发光。本系统所采用的分区LED灯光控制技术不仅可以有效节约电能,大幅延长观片灯寿命,而且还能改善医务工作者观察的舒适度。     

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.     

基于预应力锚索设计和施工要点

近些年来建筑产业经济高速发展,一些新兴技术也逐渐被人们所关注与重视。其中,预应力锚索技术在当前岩体加固施工过程中基本已实现普及推广。这是因为预应力锚索技术具备应用便捷、施工占地空间小、以及加固性能良好等优良特性,进而能够保证加固质量。基于此,以预应力锚索作为研究视角,阐述了预应力锚索具备的特性、设计要点、以及锚索施工技术要点等,以期岩体加固工程作业成果与质量得以保障。     

不张拉锚索在橙子沟水电站调压井的应用

橙子沟调压井采用打入待开挖井壁的不张拉锚索,没有工程先例。文章介绍了这种布置和结构特殊的锚索,包括其设计、施工、监测、应用前景及存在问题,为如何提高薄壁结构调压井岩石完整性和开挖稳定性提供了一种新的锚固方法。     

Estimating extreme temperature differences in steel box girder using long-term measurement data

The extreme temperature differences in fiat steel box girder of a cable-stayed bridge were studied.Firstly,by using the long-term measurement data collected by the structural health monitoring system installed on the Runyang Cable-stayed Bridge,the daily variations as well as seasonal ones of measured temperature differences in the box girder cross-section area were summarized.The probability distribution models of temperature differences were further established and the extreme temperature differences were estimated with a return period of 100 years.Finally,the temperature difference models in cross-section area were proposed for bridge thermal design.The results show that horizontal temperature differences in top plate and vertical temperature differences between top plate and bottom plate are considerable.All the positive and negative temperature differences can be described by the weighted sum of two Weibull distributions.The maximum positive and negative horizontal temperature differences in top plate are 10.30 ℃ and -13.80 ℃,respectively.And the maximum positive and negative vertical temperature differences between top plate and bottom plate are 17.30 ℃ and-3.70 ℃,respectively.For bridge thermal design,there are two vertical temperature difference models between top plate and bottom plate,and six horizontal temperature difference models in top plate.     

预应力锚索张拉应力损失的探讨和解决方法

目前在边坡加固工程的预应力锚索张拉过程中张拉应力损失是极其常见的问题,常导致张拉质量低下等严重的工程质量问题．结合一高边坡治理工地的抗滑桩锚索张拉实例,做两组平行试验,探讨锚索张拉过程的应力损失问题,发现对锚索进行预张拉能有效的减少张拉应力的损失,在工程实际允许的情况下,预张拉应力越大,张拉应力损失越小．并总结出一些合理的锚索施工方法,同样能减少张拉应力的损失．     

某高速公路边坡稳定性分析及治理

某高速公路在路基开挖后,公路左边坡存在局部滑塌问题.对该边坡进行稳定性分析,发现非滑塌区边坡处于非稳定状态.针对滑塌区和非滑塌区提出了不同的治理措施.对于滑塌区采用的治理方式为锚杆(索)+格构,并在二级马道外边设置抗滑桩;非滑塌区采用锚杆+格构的方式.然后,对治理后的边坡稳定性进行分析,结果显示治理措施合理.