新型玄武岩纤维复合材料(BFRP)锚杆力学性能研究

针对预应力锚杆的性能需求,开发了单筋型、平行索型和绞索型三种不同类型的预应力玄武岩纤维复合材料(BFRP)锚杆,研究了其拉伸、锚固和拉拔性能。结果表明,以环氧树脂作为黏结介质时,平行索的平均强度最高,达1 319 MPa。绞索由于本身捻度,受扭转作用,相较于平行索刚度和承载力有所下降,但是破坏时整体性更好,不会发生逐根破坏。采用平行-内锥式锚具时,锚杆的破坏模式为试件中间自由段纤维炸裂,锚固效率系数均大于97%。平行索的拉拔极限荷载最高,绞索的拉拔极限荷载最低,但拉拔刚度最高。

美学区连续多颗牙缺失植入位点的CBCT测量分析研究

目的:通过锥形束CT(cone beam computed tomography,CBCT)测量研究美学区连续多颗牙缺失的植入位点,为临床医师提供相应的参考依据。方法:从青岛市市立医院口腔医学中心就诊的患者中,筛选出50例患者的CBCT资料。应用CBCT配套软件对植入位点进行测量分析,并提取相关数据,采用SPSS24.0进行统计学分析。测量距离为两邻牙釉牙骨质界中点的连线至植体中心的距离。结果:CBCT测量数据显示如下,2颗中切牙缺失时,左上中切牙测量值(4.24±0.90)mm,右上中切牙测量值(4.10±0.86)mm;含侧切牙在内的2颗前牙缺失时,左上尖牙测量值(5.72±0.72)mm,左上中切牙测量值(5.10±0.73)mm,右上中切牙测量值(5.50±0.77)mm,右上尖牙测量值(4.91±0.97)mm。结论:运用CBCT测量分析美学区多颗牙连续缺失即刻植入位点所得数据,可为即刻种植理想植入位点提供理论依据。

Regulatory Expression of Peroxisome Proliferator Activated Receptors Genes During Fatty Liver Formation in Geese

In order to investigate the expression pattern of peroxisome proliferator activated receptor （PPAR） genes before and after overfeeding, and estimate the effect of expressed PPAR levels on weights of fatty liver and abdominal fat in geese, the RT-PCR products of PPAR genes in heart, liver, spleen, lung, kidney, stomach, small intestine, brain, breast muscle, leg muscle, and abdominal fat were determined before and after overfeeding. RT-PCR was used to determine the expression levels of PPAR genes. Quantity one software was used to analyze absorbency, and the expression level of GAPDH gene was used as contrast. Expression levels of PPAR-α were relatively high in most of detected tissues but undetectable in abdominal fat tissue before overfeeding, and the level was evidently increased in lung, appeared in abdominal fat tissue, and reduced in the other tissues after overfeeding. Expressed PPAR-γ levels were relatively high in liver, spleen, lung, small intestine, and abdominal fat, and relatively low in the other tissues before overfeeding. Expressed PPAR-γ levels were enhanced in liver, spleen, lung, stomach, and kidney but decreased in abdominal fat and without obvious changes in the other tissues. Expression patterns of PPAR genes show tissue-specific manner. In addition, expression patterns of PPAR-α are different from PPAR-γ after overfeeding. It might suggest that different functions of PPAR subtypes are responsive to overfeeding.

薄壁墩桥梁临时支护体系的施工监测及安全性分析——以高增大桥为例

为保障桥梁施工过程中的安全性和稳定性,需要对桥梁及其临时支护体系进行施工监测。桥梁合龙阶段涉及体系转换,需着重考虑悬臂施工过程中不平衡荷载对桥梁的影响。依托广州复建高增大桥,对薄壁墩桥梁施工过程中的临时支护体系进行监测,并建立薄壁墩桥梁的MIDAS模型,对连续梁悬臂施工过程进行了仿真分析,结合理论和仿真对薄壁墩施工过程进行安全性分析。结果表明,即使在最危险工况下,薄壁墩所承受的应力也在安全范围内,临时支护体系的施工监测保证了桥梁施工全过程的安全。