解体好氧颗粒污泥修复

考察了加入新的活性污泥使解体好氧颗粒污泥完成修复的可行性.解体好氧颗粒污泥对新加入的活性污泥进行吸附,在各种选择压力特别是水力剪切力作用下和原有颗粒污泥形成一个有机整体.大约3周时间,解体颗粒污泥被完全修复.扫描电镜观察发现,被修复后的颗粒污泥呈现非常规则的结构,微生物相十分致密.在解体颗粒污泥逐渐被修复的过程中,颗粒平均粒径仅从最初的2.8mm增至2.9mm,说明活性污泥在颗粒污泥上的附着主要发生在颗粒的空穴.而颗粒污泥的沉降性能和强度都得到了极大的改善,颗粒沉降速率和完整性系数分别由最初的72m/h和56.8%提高到110m/h和65.8%.新加入的活性污泥除了部分用于修复解体颗粒污泥,其余在选择压力等的作用下形成了新的好氧颗粒污泥.     

含有改性混凝土叠合层的T形梁抗裂性能研究

基于8根混凝土倒T形叠合梁受弯试验,研究了钢筋钢纤维自应力混凝土做加固材料层二次浇注到待加固混凝土T形梁,从而形成的叠合梁在负弯矩区的抗裂性能.试验结果表明,仅占叠合梁高13.9%的叠合层将梁的开裂弯矩提高44.9%.同时根据已有理论模型,推导了自应力混凝土叠合T梁后加自应力的求法和负弯矩区正截面抗裂计算公式,其计算结果与试验结果比较吻合.     

Structure of the gating domain of a Ca2+-activated K+ channel complexed with Ca2+/calmodulin

Small-conductance Ca2+-activated K+ channels (SK channels) are independent of voltage and gated solely by intracellular Ca2+. These membrane channels are heteromeric complexes that comprise pore-forming alpha-subunits and the Ca2+-binding protein calmodulin (CaM). CaM binds to the SK channel through the CaM-binding domain (CaMBD), which is located in an intracellular region of the alpha-subunit immediately carboxy-terminal to the pore. Channel opening is triggered when Ca2+ binds the EF hands in the N-lobe of CaM. Here we report the 1.60 A crystal structure of the SK channel CaMBD/Ca2+/CaM complex. The CaMBD forms an elongated dimer with a CaM molecule bound at each end; each CaM wraps around three alpha-helices, two from one CaMBD subunit and one from the other. As only the CaM N-lobe has bound Ca2+, the structure provides a view of both calcium-dependent and -independent CaM/protein interactions. Together with biochemical data, the structure suggests a possible gating mechanism for the SK channel.     

柔性衬底上铝背电极制备及相关特性研究

采用射频磁控溅射技术在聚酰亚胺柔性衬底上制备硅基薄膜太阳能电池用铝背电板,研究了不同溅射功率和工作气压条件对铝电极薄膜性能的影响.利用原子力显微镜分析表征了薄膜的表面形貌和粗糙度,薄膜的电学性能和光学性能分别采用四探针测量仪和紫外可见近红外分光光度计进行分析表征.测试结果表明:随着溅射功率的增加,薄膜表面均方根粗糙度迅...