面向关键信息基础设施的网络安全评价体系研究

随着互联网和云计算的广泛应用,关键信息基础设施安全问题日益突出。当前关键信息基础设施安全保障评价指标体系的三层分级结构存在缺乏量化指标以及管理指标与技术指标缺乏关联等问题,这些问题导致安全风险评估过程信息化程度低、周期长。针对上述问题,文章引入知识图谱建立管理指标和技术指标之间的关联,同时通过实际态势数据分类细化技术指标,形成基于知识图谱技术的网络安全四级量化评价体系。通过监管部门实际应用,该体系可以实时地对关键信息基础设施的互联网资产进行网络安全风险评估,显著提升监管效率。

Effects of Spherical Light-weight Aggregates Additions on Workability and Mechanical Properties of Al_2O_3-SiO_2 System Castables

In order to clarify the effect of spherical light-weight aggregates addition on properties of A12 07 - Si02 system castables, adopting ATO mullite traditional light-weight aggregates and ATO mullite spherical light-weight aggre- gates, bauxite homogenization powder, microsilica , cal- cium aluminate cement as main raw materials, light- weight Al2 03 - SiO2 system castables were prepared by replacing conventional light-weight aggregate with spherical light-weight aggregates. The effects of spheri- cal light-weight aggregates addition on workability, me- chanical properties of castables after heated at different temperatures were researched; the microstructure of the aggregates was analyzed by SEM. The result shows that the introduction of spherical light-weight aggregates can significantly improve the flowability and reduce the water addition of the castables. Water demand of the castable is reduced from 18% with the conventional light-weight aggregates to 14% with spherical light-weight aggre- gates. In addition, light-weight castables prepared by spherical aggregates can keep the same workability with- in a wider range of water addition. Therefore, spherical aggregates are user-friendly. The introduction of spheri- cal light-weight aggregates is favorable to packing densi- ty and mechanical properties of castables, such as cold crushing strength, cold modulus of rupture, hot modulus of rupture at 1 200℃.

微笑佛首背后的文明回响

2021年2月11日农历春节除夕,流失海外近百年的太原天龙山石窟第8窟北壁主尊佛首,作为2020年回归祖国的第100件流失文物,亮相中央广播电视总台春节联欢晚会。开凿于隋朝,距今已有1400余年的佛首见证了天龙山石窟千年前的繁荣,也承受了百年前毁于一旦的浩劫,21世纪新时代又将见证中华民族的伟大复兴。