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In this work, toppling failure of a jointed rock slope is studied by using the distinct lattice spring model (DLSM). The gravity increase method (GIM) with a sub-step loading scheme is implemented in the DLSM to mimic the loading conditions of a centrifuge test. A classical centrifuge test for a jointed rock slope, previously simulated by the finite element method and the discrete element model, is simulated by using the GIM-DLSM. Reasonable boundary conditions are obtained through detailed comparisons among existing numerical solutions with experimental records. With calibrated boundary conditions, the influences of the tensional strength of the rock block, cohesion and friction angles of the joints, as well as the spacing and inclination angles of the joints, on the flexural toppling failure of the jointed rock slope are investigated by using the GIM-DLSM, leading to some insight into evaluating the state of flexural toppling failure for a jointed slope and effectively preventing the flexural toppling failure of jointed rock slopes.

Several researchers have extensively investigated the flow-induced vibrations caused by flood release because numerous structures have been destroyed by such release. Nevertheless, none of the previous research has considered vibration safety during flood control operation. In this study, a hedging scheduling model considering the near-field vibrations induced by flood release and hydrological uncertainty is proposed to optimize the discharge process. The dispatch model was applied to the Xiangjiaba reservoir due to the reservoir’s classic problem of near-field vibrations induced by flood release. The measured root-mean square (RMS) data for the acceleration in the vertical direction of near-field vibrations were used to summarize safety constraints. The vibration safety discharge ceiling was determined according to field test records and was regarded as an operational safety constraint for the dispatch model. Based on this innovative safety constraint, this paper demonstrates the development of an optimal dispatch model for reservoirs by considering forecast uncertainty. The proposed strategy utilizes storage capacity to optimally allocate the gap between the expected flood volume and vibration safety discharge capacity (GBEV) in the discharge process. Optimal flood control operation considering the near-field vibrations induced by flood release falls into four categories, with each category corresponding to one optimal operation strategy. The solution set to this model can provide decision support for reservoirs with similar flood-induced vibration problems and optimize the power output of hydropower stations.

A two-phase flow model accelerated by graphical processing unit (GPU) is developed to solve fluid-solid interaction (FSI) using the sharp-interface immersed boundary method (IBM). This model solves the incompressible Navier-Stokes equations using the projection-based fractional step method in a fixed staggered Cartesian grid system. A volume of fluid (VOF) method with second-order accuracy is employed to trace the free surface. To represent the intricate surface geometry, the structure is discretized using the unstructured triangle mesh. Additionally, a ray tracing method is employed to classify fluid and solid points. A high-order stable scheme has been introduced to reconstruct the local velocity at interface points. Three FSI problems, including wave evolution around a breakwater, interaction between a periodic wave train and a moving float, and a 3-D moving object interacting with the free surface, were investigated to validate the accuracy and stability of the proposed model. The numerical results are in good agreement with the experimental data. Additionally, we evaluated the computational performance of the proposed GPU-based model. The GPU-based model achieved a 42.29 times speedup compared with the single-core CPU-based model in the three-dimension test. Additionally, the results regarding the time cost of each code section indicate that achieving more significant acceleration is associated with solving the turbulence, advection, and diffusion terms, while solving the pressure Poisson equation (PPE) saves the most time. Furthermore, the impact of grid number on computational efficiency indicates that as the number of grids increases, the GPU-based model outperforms the multi-core CPU-based model.

The cause of longitudinal cracks on the top of the large locks built on soft foundations can’t be explained by general design methods. Based on the analysis of influence of foundation elastic rebound and concrete hardening on the response of elastic foundation beam, the paper thinks it is an important cause that designers ignore the above factors of the construction process, and considering the worst case, and suggests designers should ignore the affection of the lock floor’s deadweight when computing the negative moment.

Dam safety monitoring data can be viewed as a digital signal sequence which consists of different frequency components. Identifying outliers to ensure the reliability of observational data becomes a foundation work of dam monitoring data analysis. Outliers of time signal series can be detected by wavelet transform. Lipschitz index can be used to measure the local singularity of a function, and the original abnormal signal can be found in the position of wavelet transform modulus maxima. Take horizontal displacement values observed by Lijiaxia concrete dam as example, an assumed error are added to the time series signal deliberately. A 4-level decomposition of the observation data was done by using wavelet db1, the results show that the modulus maxima occur at the given time. Therefore, outliers can be detected and located accurately by wavelet transform, which is important to analyze the safety monitoring data of dam.

Modular steel construction (MSC) has exhibited widespread applications in civil engineering. The inter-module connection is a key issue for the seismic performance of MSC. A detailed finite element model (FEM) of a new type of bolted connection was firstly developed. Its accuracy was validated by comparing numerical results with previous experimental results in terms of hysteretic curve and failure mode. A theoretical mechanical model was developed and its capabilities on predictions of initial rotational stiffness and ultimate moment resistance of the connection were checked through validations against test results. Further, a parametric study on several specimens with different axial load ratios, boundary conditions and section of the beams was conducted. The prediction capability of the theoretical model on seismic behavior of the connection with different beam sections was checked by comparing the skeleton curves of FEA results with theoretical ones. Subsequently, a simplified FEM was established and validated to accelerate the numerical simulation of the seismic performance of the connection.

Salvianolic acid A （SAA）, a water-soluble phenolic acid isolated from the root of Dan Shen, displays distinct antioxidant activity and effectiveness in protection against cerebral ischemia/reperfusion （I/R） damage. However, whether SAA can enter the central nervous SYstem and exert its protective effects by directly targeting brain tissue remains unclear. In this study, we evaluated the cerebral protection of SAA in rats subjected to transient middle cerebral artery occlusion （tMCAO） followed by reperfusion. The rats were treated With SAA （5, 10 mg/kg, iv） when the reperfusion was performed. SAA administration significantly decreased cerebral infarct area and the brain water content, attenuated the neurological deficit and pathology, and enhanced the anti-inflammatory and antioxidant capacity in tMCAO rats. The concentration of SAA in the plasma and brain was detected using LC-MS/MS. A pharmacokinetic study revealed that the circulatory system exposure to SAA was equivalent in the sham controls and I/R rats, but the brain exposure to SAA was significantly higher in the I/R rats than in the sham controls （fold change of 9.17）, suggesting that the enhanced exposure to SAA contributed to its cerebral protective effect. Using a GC/MS-based metabolomic platform, metabolites in the serum and brain tissue were extracted and profiled. According to the metabolomic pattern of the tissue data, SAA administration significantly modulated the I/R-caused perturbation of metabolism in the brain to a greater extent than that in the serum, demonstrating that SAA worked at the brain tissue level rather than the whole circulation system. In conclusion, a larger amount of SAA enters the central nervous system in -ISchemia/reperfusion rats to facilitate its protective and regulatory effects on the perturbed metabolism.

Based on inequality techniques and matrix theory, linear feedback control both with one input and one state or two states and with multi-inputs is proposed to realize the globally exponential synchronization of two Chu chaotic systems. Some new sufficient algebraic criteria for the globally exponential synchronization of two chaotic systems are obtained analytically. The controllers here designed have simple structure. Numerical simulations are presented to show the effectiveness of the proposed chaos synchronization scheme.

This article reports the effects of phosphorus addition on the melting behavior, microstructure, and mechanical properties of Sn3.0Ag0.SCu solder. The melting behavior of the solder alloys was determined by differential scanning calorimetry. The interracial micro- structure and phase composition of solder/Cu joints were studied by scanning electron microscopy and energy dispersive spectrometry. Thermodynamics of Cu-P phase formation at the interface between Sn3.0Ag0.5Cu0.5P solder and the Cu substrate was characterized. The results indicate that P addition into Sn3.0Ag0.5Cu solder can change the microstructure and cause the appearance of rod-like CuaP phase which is distributed randomly in the solder bulk. The Sn3.0Ag0.5Cu0.5P joint shows a mixture of ductile and brittle fracture after shear test- ing. Meanwhile, the solidus temperature of Sn3.0Ag0.5Cu solder is slightly enhanced with P addition.

Aim： To study the effect of pSilencerl.0-U6-siRNA-stat3 on the growth of human laryngeal tumors in nude mice. Methods： Hep2 cells were transplanted into nude mice, then at the time of tumor formation, growth rates were observed. After the tumor formed, pSilencerl.0-U6-siRNA-stat3 was injected. Tumor volumes were calculated, and growth curves were plotted. Representative histological sections were taken from mice bearing transplantation tumors in both treated and control groups, and stat3, pTyr-stat3, Bcl-2, cyclin D1, and survivin expression were detected by Western blotting, survivin mRNA levels were detected by Northern blotting, hematoxylin and eosin staining and terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labeling （TUNEL） assay to confirm the apoptosis of tumors. Results： In nude mice, pSilencerl.0-U6-siRNA-stat3 significantly suppressed the growth of tumors compared with controls （P〈0.01）. It suppressed stat3 expression, and downregulated BcL2, cyclin D1, and survivin expression within the tumor. This significantly induced apoptosis of the tumors. Conclusion： pSilencerl.0-U6-siRNA-stat3 was able to inhibit the growth of transplanted human laryngeal tumors in nude mice and induce apoptosis.