预应力碳纤维布加固损伤混凝土梁非线性有限元分析

采用ANSYS有限元分析软件,对不卸载时预应力碳纤维布加固钢筋混凝土梁的受力变形性能进行了计算分析。计算中采用升温法来施加预应力,利用单位的生与死来实现不卸载时的加固。通过与试验结果进行对比可知,数值计算结果与试验分析结果吻合较好。在此基础上,对不同初始损伤量及CFRP加固量进行了扩展计算可知,初始损伤梁对混凝土梁承载能力几乎无影响,通过增加CFRP加固层数能有效提高混凝土梁的承载能力。     

1 株广谱抗菌活性菌株的筛选鉴定及其抗菌蛋白的分离纯化

从湖南传统腊肉中分离筛选得到1 株具有广谱抑菌活性的菌株HLR13,该菌株发酵液对蜡样芽孢杆菌、荧光假单胞菌、藤黄微球菌和肠炎沙门菌等食品中常见的致病菌具有较强的抑制活性。通过形态学特征、生理生化特征及16S rRNA序列分析,该菌株被鉴定为枯草芽孢杆菌斯皮兹仁亚种（Bacillus subtilis subsp. spizienii）。采用硫酸铵分级沉淀、离子交换层析（Q Sepharose FF）和凝胶过滤层析（Sephadex G-75）等方法对该菌株所产抗菌蛋白进行分离纯化,经十二烷基硫酸钠-聚丙烯酰胺凝胶电泳检测显示纯化后的蛋白为单一条带,通过基质辅助激光解吸电离飞行时间质谱分析和NCBI/nr蛋白数据库比对初步确定该抗菌蛋白分子质量为31?494?Da,是枯草芽孢杆菌产生的一种假定蛋白。本实验可为新型天然防腐剂的开发提供一定理论依据。     

基于概率神经网络的智能火灾报警系统

针对目前火灾报警系统灵敏度低、可靠性差等不足,提出和设计了基于概率神经网络(PNN)的分布智能型火灾报警系统.概率神经网络具有训练速度快,结构简单,非线性处理和抗干扰能力强等特点,可以提高火灾报警的灵敏度和可靠性.     

城域管道及光缆建设的趋势——浅谈光缆传输微型化

本文介绍了在城域光缆建设方面即将成为主流的一种全新的建设方式。     

一种构造GC常重量DNA码的方法

GC重量是DNA码的一个重要参数,如何构造满足GC常重量约束的DNA码是一个有趣的问题。该文通过在DNA码与四元码之间建立一个双射,将构造满足GC常重量约束的DNA码转化为构造GC常重量四元码。通过代数的方法,构造了3类满足GC常重量约束的DNA码。     

Antioxidase-Like Nanobiocatalysts with Ultrafast and Reversible Redox-Centers to Secure Stem Cells and Periodontal Tissues

Exploration of efficient antioxidase-like reactive oxygen nanobiocatalysts (ROBCs) is a major challenge in combating oxidative stress-related diseases. Herein, the molecularly well-defined Ru-porphyrin-networks (Ru-Por-Net)-based ROBCs with ultrafast and reversible redox-centers for catalytic elimination of reactive oxygen species (ROS) are reported. Owing to the large π-conjugated networks, Ru–N coordination structures, and unique electronic and redox properties of atomic Ru sites, the Ru-Por-Net-based ROBCs exhibit exceptional catalytic ROS-scavenging activities. It is considerably more efficient than recently reported state-of-the-art anti-ROS biocatalysts. Notably, a new nucleophilic attack pathway to eliminate H₂O₂ and produce O₂ is proposed via theoretical calculations, and the desorption of the OO* process is identified as the rate-determining step of atomic Ru centers. Cellular studies reveal that the new ROBCs can efficiently secure the survival, adhesion, spreading, and differentiation of the stem cells in high-ROS-level microenvironments. In vivo rat periodontitis treatments further demonstrate their superior anti-ROS therapeutic effects. This study provides significant insights into the crucial functions of Ru–N coordinated porphyrin-networks in catalytic ROS-scavenging and offers a new strategy to engineer high-performance antioxidase-like nanobiocatalysts for stem cell-based therapies and inflammatory diseases.     

Tunable Structured Metal Oxides for Biocatalytic Therapeutics

The past few decades have witnessed the flourish of creating metal oxides for biocatalytic therapeutics due to their structural diversities, feasible modifications, tunable catalytic sites, and low cost when compared to their natural enzyme counterparts. Here, in this timely review, the most recent progress and future trends in engineering tunable structured metal oxides and decoding their structure-reactivity relationships for biocatalytic therapeutics is comprehensively summarized. At first, the fundamental activities, evaluations, and mechanisms of metal oxide-based biocatalysts are carefully disclosed. Subsequently, the merits, design methods, and state-of-art achievements of different types of nanostructured and biofunctionalized metal oxides are thoroughly discussed. Thereafter, it provides detailed comments on the catalytic center modulation strategies to engineer metal oxides for efficient reactive oxygen species (ROS)-catalysis, including atomic catalytic site engineering, heterostructures, and support effects. Furthermore, the representative applications of these ROS-catalytic metal oxides have been systematically summarized, such as catalytic disinfections, cancer therapies, ROS scavenging and anti-inflammations, biocatalytic sensors, as well as corresponding toxicities. Finally, current challenges and future perspectives are also highlighted. It is believed that this review can provide cutting-edge and multidisciplinary instruction for the future design of ROS-catalytic metal oxides and stimulate their widespread utilization in broad therapeutic applications.