Mechanism of the slow-moving landslides in Jurassic red-strata in the Three Gorges Reservoir, China

Landslides in Jurassic red-strata make up a great part of geohazards in the Three Gorges Reservoir (TGR) in China. Most of them begin to move slowly with the accumulated displacement increasing stepwise, which corresponds to seasonal rainfall and 30 m of reservoir water level fluctuation (145 m to 175 m on elevation). We analyzed the movement of 21 slow moving landslides in the Jurassic red-strata in TGR, and found that all these landslides involved two differing processes; one is the sliding process with different shear speeds of soils within the sliding zone (landslide activity), and the other one is in steady state with different durations (dormant state). This means that the soil within the sliding surface may experience shearing at different shear rates and recovery in shear strength during the dormant period. To clarify the mechanism of this kind of movement, we took soil samples from the sliding surface of Xiangshanlu landslide, which occurred on August 30, 2008 in the Jurassic red-strata in TGR, and examined the shear rate dependency and recovery of shear resistance by means of ring shear tests. The results of tests at different shear rates show that the shear strength is positively dependent on the shear rate, and can be recovered within a short consolidation duration after the shearing ceased. By increasing the pore-water pressure (PWP) from the upper layer of the sample, we also examined the initiation of shearing which can simulate the restart of landsliding due to the fluctuation of groundwater level caused by rainfall or changes in reservoir water level. The monitored PWP near the sliding surface revealed that there was a delayed response of PWP near the sliding surface to the applied one. This kind of delayed response in pore-water pressure may provide help for the prediction of landslide occurrence due to rainfall or fluctuation of reservoir water level

Self-consistent field theory of polarized BEC: dispersion of collective excitation

We suggest the construction of a set of the quantum hydrodynamics equations for the Bose-Einstein condensate (BEC), where atoms have the electric dipole moment. The contribution of the dipole-dipole interactions (DDI) to the Euler equation is obtained. Quantum equations for the evolution of medium polarization are derived. Developing mathematical method allows to study effect of interactions on the evolution of polarization. The developing method can be applied to various physical systems in which dynamics is affected by the DDI. Derivation of Gross-Pitaevskii equation for polarized particles from the quantum hydrodynamics is described. We showed that the Gross-Pitaevskii equation appears at condition when all dipoles have the same direction which does not change in time. Comparison of the equation of the electric dipole evolution with the equation of the magnetization evolution is described. Dispersion of the collective excitations in the dipolar BEC, either affected or not affected by the uniform external electric field, is considered using our method. We show that the evolution of polarization in the BEC leads to the formation of a novel type of the collective excitations. Detailed description of the dispersion of collective excitations is presented. We also consider the process of wave generation in the polarized BEC by means of a monoenergetic beam of neutral polarized particles. We compute the possibilities of the generation of Bogoliubov and polarization modes by the dipole beam.Comment: 16 pages, 15 figures. arXiv admin note: substantial text overlap with arXiv:1106.082

Automatic Lip-Reading System Based on Deep Convolutional Neural Network and Attention-Based Long Short-Term Memory

With the improvement of computer performance, virtual reality (VR) as a new way of visual operation and interaction method gives the automatic lip-reading technology based on visual features broad development prospects. In an immersive VR environment, the user’s state can be successfully captured through lip movements, thereby analyzing the user’s real-time thinking. Due to complex image processing, hard-to-train classifiers and long-term recognition processes, the traditional lip-reading recognition system is difficult to meet the requirements of practical applications. In this paper, the convolutional neural network (CNN) used to image feature extraction is combined with a recurrent neural network (RNN) based on attention mechanism for automatic lip-reading recognition. Our proposed method for automatic lip-reading recognition can be divided into three steps. Firstly, we extract keyframes from our own established independent database (English pronunciation of numbers from zero to nine by three males and three females). Then, we use the Visual Geometry Group (VGG) network to extract the lip image features. It is found that the image feature extraction results are fault-tolerant and effective. Finally, we compare two lip-reading models: (1) a fusion model with an attention mechanism and (2) a fusion model of two networks. The results show that the accuracy of the proposed model is 88.2% in the test dataset and 84.9% for the contrastive model. Therefore, our proposed method is superior to the traditional lip-reading recognition methods and the general neural networks

Innovation, Mark-Up and Firm Growth: Evidence from China’s New Generation IT Industry

In this paper, we provide empirical evidence for understanding the growth behavior of China’s new generation of information technology (IT) industrial firms and the impact of innovation and market power on them. Based on the data of China’s new generation IT industrial firms covering the period 2000–2007, we use ordinary least square (OLS) and two-stage least squares (IV-2SLS) methods to study the effects of innovation and markup on the growth of China’s new generation IT industrial firms in the framework of Gibrat’s law. IV-2SLS estimations show that: (1) Innovation and markup have positive and significant effects on the firm’s total revenue growth rate, but have no significant or negative effects on the growth rate of the firm’s total assets and employment. (2) Innovation has a positive and significant effect on the firm’s mark-up. The results indicate that for China’s new generation IT industrial firms which are technology-intensive, improving the technological innovation and market power will reduce the firm’s input and increase the firm’s output. Innovation can significantly increase the firm’s mark-up. (3) From the perspective of the dynamic evolution of a firm’s growth, firm size has a negative and significant impact on the firm growth while firm age has a positive and significant impact on the firm’s growth. In addition, we also examine the different effects of capital intensity and export demand on the firm’s growth

Seepage-deformation mechanism of colluvial landslides under the action of reservoir water level decline and rainfall

Objective With the construction of reservoir projects, the problem of deformation and instability of colluvial landslides in reservoir areas has become increasingly prominent. These landslides often experience deformation during the period of reservoir water level decline particularly exacerbated by rainfall. Therefore, the seepage-deformation mechanism of landslides under the joint action of reservoir water level decline and rainfall is one of the key scientific issues. Methods In this paper, a typical colluvial landslide in the Three Gorges Reservoir Area, the Shilongmen landslide, is used as a prototype. Physical model tests were designed to observe the macroscopic phenomena of the slope body and the pressure changes in the slope during combined scenarios of reservoir level drops and rainfall of different intensities, revealing the seepage-deformation mechanism of the colluvial landslide under complex hydrological conditions. Results The test results indicated that the decrease in reservoir level has a more obvious effect on the control of seepage at the front of the slope, while rainfall significantly raises the water head at the middle and rear of the slope, and the combination of the two will increase the hydraulic gradient in the slope, thus inducing slope deformation. Conclusion The seepage-deformation mechanism of the colluvial landslide when the reservoir level drops is as follows: In the absence of rainfall, only shallow surface scouring action occurs due to the difference between the internal and external heads of the slope. Under the condition of the worst rain in a 100-year rainstorm, cracks appear near the high water level, and then overall deformation occurs, with a maximum displacement of 58.3 mm. This study can provide a theoretical basis for the prevention and control of colluvial landslides under complex hydrological conditions

Improved slope unit method for fine evaluation of regional landslide susceptibility

Susceptibility evaluation is the basis of regional landslide risk early warning and stability analysis. Scientific and reasonable division of evaluation unit is the key to landslide susceptibility evaluation. For large-scale fine landslide susceptibility evaluation, the traditional slope unit division method based on hydrology and geomorphology generally results in low accuracy of the evaluation. In this paper, an improved slope unit method based on the slope geological environment is proposed. Dazhou Town was selected as an example and the obtained results from the proposed model were compared with the results from hydrological analysis method and curvature watershed method. The results show that the size uniformity of the evaluation units divided by the proposed method is better, and no fine units or deformed long strip units were generated. The overall morphological characteristics of the evaluation unit are more reasonable, and the morphological index is between 1 and 2, which generally presents circular-like or square-like shape. At the same time, the superposition degree between the results of the improved slope unit division and the range of the existing disaster boundary is the highest, which can better reflect the physical significance of landslide risk assessment. The proposed model has significant potential for improving the accuracy of regional landslide susceptibility evaluation

Study on the effect of tower foundation landslide protection measures based on a physical model test

A large number of high voltage transmission tower foundations crossing mountainous and hilly areas are often located in high-prone slope areas of landslide disasters. Applying appropriate protective measures to improve their stability is the key to ensuring the continuous and safe operation of transmission lines. To study the protection effect of different protection measures on the tower foundation landslide, this paper takes the Yanzi landslide in Badong County, Hubei Province as a geological prototype, designs and produces a physical test model, and carries out physical model tests of the landslide under extreme rainfall conditions(50, 100 mm/h) without protection, applying anti-slide piles and lattice protection. The deformation and failure characteristics of the landslide and the protective effect of different protective measures are revealed from the experimental point of view. The results show that under two extreme conditions, the unprotected landslide experienced the evolution process of slope surface erosion, crack propagation, local collapse and deformation, and overall sliding. The anti-slide pile measures have a significant effect on the overall protection of the landslide. The landslide is in a stable state, the deformation of the tower foundation is small, and the inclination rate of the tower meets the specification, but the slope surface will be scoured and collapsed. Lattice slope protection measures can effectively reduce the risk of slope erosion and slope toe collapse, but the overall stabilization of the tower foundation under continuous heavy rainfall is slightly weaker. The model test results are consistent with the historical deformation of the landslide and the actual treatment effect. The test conclusions can provide a reference for the failure mechanism research and protection engineering design of similar tower foundation landslides

A Study on Hydrochemical Characteristics and Evolution Processes of Groundwater in the Coastal Area of the Dagujia River Basin, China

Groundwater resource is vital for industrial, drinking and irrigation purposes in the Dagujia river basin, China. The objective of this work was to comprehensively assess the hydrochemical characteristics and evolution processes of the Quaternary aquifer (QA) and the bedrock aquifer (BA) of the basin using statistical methods and hydrochemical plots. In total, 56 groundwater samples were collected from the QA (34 samples) and BA (22 samples). In addition, statistical methods combined with the geographic information system were used to identify the hydrochemical parameters of groundwater, as well as its spatial distribution in the Dagujia river basin. The Piper diagram showed that Ca-Na-HCO3 was the dominant groundwater facies type, while nine QA samples collected near the coastal line showed the Na-Cl facies type. On the other hand, the Gibbs diagram showed that most samples fell in the rock dominance zone. The principal component analysis results showed that the water–rock interaction and anthropogenic activities are the controlling factors, which is consistent with the results obtained using other methods. The results of this study indicated that rock weathering controls the hydrochemical characteristics of groundwater, while anthropogenic contamination and sea water intrusion are becoming increasingly serious issues for both QA and BA in the Dagujia river basin. Therefore, both Quaternary and bedrock aquifers require more attention