Influence of bedrock depth on the seismic response of a nuclear reactor building foundation considering soil structure interaction

Earthquakes events can impact on safety of nuclear power plants. With the increasing number of nuclear power plants, the necessity of seismic safety of nuclear power plants becomes higher than ever before. Nuclear reactor building is an important part of nuclear power plant, so the importance to understand its seismic response is critical.Adopting the direct method, this paper utilized FLAC3D to model the soil-nuclear reactor building three-dimensionally on three different site conditions(medium hard soil, soft rock and hard rock).To capture the separation and sliding between the superstructure and the rock/soil deposit, Interface elements were set between the foundation of the nuclear reactor building and the rock/soil surface. The superstructure was simulated by lumped mass model, and the influence of bedrock depth on the seismic response of nuclear reactor building was investigated considering soil structure interaction. Finally, the acceleration response spectrum, shear force, foundation rocking, foundation differential settlement and lateral displacement of the structural members of the nuclear reactor building were obtained. The results show that the displacement and shear force decreased with the increasein bedrock depth in medium hard soil; In the hard rock site, the trends tended to be opposite; However, under the condition of soft rock site, the response of superstructure is more complex. For the foundation rocking and differential settlement, in the medium hard soil site, the reactions decreased with the increase in bedrock depth; In soft and hard rock sites, there is no obvious trend. The differential settlement of foundation can directly reflect the damage of structure. The results show that the differential settlement of foundation in medium hard soil site exceeded the allowable value, so the influence of differential settlement of foundation on nuclear reactor building can not be ignored, which is important for the safety design of nuclear power plant

Role of Zhiqiao Chuanlian decoction in the treatment of food accumulation fever: Network pharmacology and animal experiments

Objective: Food accumulation fever (FAF), a common clinical disease in children, is generally induced by the excessive intake of high-calorie or high-fat foods. Zhiqiao Chuanlian decoction (ZQCLD) is a classical traditional Chinese medicine (TCM) that may have therapeutic effects on FAF. Methods: Network pharmacological analyses of ZQCLD and FAF were conducted. Animal experiments lasted for 14 days. Rats in the model, positive control, and low-, medium-, and high-dose groups were fed a high-calorie diet. On days 11–14, the positive group was given a domperidone solution. The low-, medium-, and high-dose groups were administered different concentrations of ZQCLD. The body temperature, gastric emptying rate, and intestinal propulsion rate were measured. Relevant indicators were determined by ELISA. Results: The main target proteins included IL-1β, C–C motif chemokine 2 (CCL2), prostaglandin G/H synthase 2 (PTGS2), transcription factor AP-1 (JUN), haem oxygenase 1 (HMOX1), interferon-gamma (IFN-γ), peroxisome proliferator-activated receptor-gamma (PPAR-γ), and inducible nitric oxide synthase (NOS2/iNOS). Compared with those in the control group, body weight, gastric emptying rate, intestinal propulsion rate, and neuronal nitric oxide synthase (NOS1/nNOS) levels were significantly lower in the model group, whereas body temperature and endotoxin, interleukin-1β (IL-1β), PGE2, and iNOS levels were increased. In each treatment group, body temperature and PGE2 levels returned to normal levels. Compared with those in the model group, the gastric emptying rates in the positive group and the low- and medium-dose groups increased; the intestinal propulsion rates were higher in the medium- and high-dose groups, whereas the endotoxin and IL-1β levels were lower; and the nNOS level was higher in the high-dose group, whereas the iNOS level was lower. Conclusions: ZQCLD may treat FAF by regulating jejunal IL-1β and nNOS, serum endotoxin, and hypothalamic PGE2 and iNOS levels