重大疫情防控中的网络舆情及其信息治理策略——基于“弹簧”动力模型分析

[目的/意义]遵循网络舆情演化规律开展高质量的信息治理,是有效化解重大疫情防控中网络舆情事件的必然选择,也是对重大疫情防控精准化、科学化水平的重要检验。[方法/过程]基于弹簧运动的受力原理,借助系统动力学及营力系统理论建构一种“弹簧”动力模型,用以描述信息压力、信息支持力、信息驱动力、信息阻滞力等内外营力的相互作用,以及这些作用力在网络舆情蓄力生成、反弹加速、异化驱动、减速终结等四个动态演进阶段的各自表征。[结果/结论]重大疫情防控中网络舆情的信息治理策略应从前置端口环节守住信息传播“关口”,从中间过程环节打造数字治理格局,从后置反馈环节强化网络舆情监管。

土体震致剪切变形条件下斜坡桩的受力特性

为了研究斜坡土体震致剪切变形条件下桩基的受力特性,结合土体多屈服面模型和桩土动力弹簧模型,建立了斜坡—桩基体系整体数值模型。通过输入幅值为0.4809 g的EI-centro地震波,考虑不同的坡角和桩径条件,进行了非线性动力时程计算。结果表明:在地震荷载作用下,不同深度处斜坡土体剪切变形存在差异,斜坡群桩基础受力不均衡。斜坡坡角对斜坡土体剪切变形发展和桩身残余弯矩起控制作用,而桩径对其的影响相对较小。本研究工作对斜坡桩基抗震设计具有一定的参考意义。

Static-deformation based fault diagnosis for damping spring of large vibrating screen

Based on the statics theory, a novel and feasible twice-suspended-mass method(TSMM) was proposed to deal with the seldom-studied issue of fault diagnosis for damping springs of large vibrating screen(LVS). With the static balance characteristic of the screen body/surface as well as the deformation compatibility relation of springs considered, static model of the screen surface under a certain load was established to calculate compression deformation of each spring. Accuracy of the model was validated by both an experiment based on the suspended mass method and the properties of the 3D deformation space in a numerical simulation. Furthermore, by adopting the Taylor formula and the control variate method, quantitative relationship between the change of damping spring deformation and the change of spring stiffness, defined as the deformation sensitive coefficient(DSC), was derived mathematically, from which principle of the TSMM for spring fault diagnosis is clarified. In the end, an experiment was carried out and results show that the TSMM is applicable for diagnosing the fault of single spring in a LVS.