Slope stability analysis under seismic load by vector sum analysis method

AbstractThe vibration characteristics and dynamic responses of rock and soil under seismic load can be estimated with dynamic finite element method (DFEM). Combining with the DFEM, the vector sum analysis method (VSAM) is employed in seismic stability analysis of a slope in this paper. Different from other conventional methods, the VSAM is proposed based on the vector characteristic of force and current stress state of the slope. The dynamic stress state of the slope at any moment under seismic load can be obtained by the DFEM, thus the factor of safety of the slope at any moment during earthquake can be easily obtained with the VSAM in consideration of the DFEM. Then, the global stability of the slope can be estimated on the basis of time-history curve of factor of safety and reliability theory. The VSAM is applied to a homogeneous slope under seismic load. The factor of safety of the slope is 1.30 under gravity only and the dynamic factor of safety under seismic load is 1.21. The calculating results show that the dynamic characteristics and stability state of the slope with input ground motion can be actually analyzed. It is believed that the VSAM is a feasible and practical approach to estimate the dynamic stability of slopes under seismic load

China and the knowledge economy : challenges and opportunities

The rapid pace of economic growth in China has been unprecedented since the start of economic reforms in late 1970s. It has delivered higher incomes and made the largest single contribution to global poverty reduction. Measured by international poverty lines, from 1978-2004, the absolute poor population in rural areas has dropped from 250 million to 26.1 million. Such gains are impressive and have been driven largely by a set of market-oriented institutional reforms, strong investment, and effective adoption and application of various knowledge and technologies, especially foreign ones through trade and foreign direct investment. While enjoying tremendous success, China also faces many challenges that need to be addressed to sustain its long-term development. These include weak institutions, low overall educational attainment, weak indigenous innovation capacity, poor links between research and development and industries, and so on. This paper provides an analysis of some strengths, weaknesses, opportunities, and challenges to China's knowledge economy in the areas of economic incentives and institutional regime, human capital, innovation system, and information infrastructure.

Challenges to China’s Education and Training System and the New Global Context

To put the need for developing a system of lifelong learning for China in context, this chapter begins by summarizing some of the daunting challenges China is facing in education and training. It summarizes some of the key elements of what could be called a knowledge revolution that are making education and training critical elements of competitiveness. It then summarizes some of the key global trends in education and training. It concludes with a section of why investments in education and training are important in this new global context of rapid change and constant restructuring

Synthesis of natural porous minerals supported TiO2 nanoparticles and their photocatalytic performance towards Rhodamine B degradation

Natural porous mineral supported (TiO/diatomite) photocatalyst was prepared via a modified sol-gel method using titanium (IV) butoxide (TBOT) and diatomite. The effect of TBOT dosage on adsorption capacity and photocatalytic activity for Rhodamine B (RhB) solution was investigated. The morphology and elemental distribution were determined by scanning electron microscopy with attached energy-dispersive X-ray detector. The porous and crystalline structures were characterized using nitrogen adsorption-desorption and X-ray diffraction techniques, respectively. The prepared TiO/diatomite hybrid catalyst has shown relatively even porous structure and dispersion of TiO over the surface. This suggests that the diatomite matrix prevented the agglomeration of TiO particles. Initially, the surface area and pore volume of the hybrid catalyst were increased by adding TBOT then decreased for dosages higher than 1.0ml. The crystalline size of TiO immobilized on diatomite matrix by sol-gel method was around 20nm. When the experiments were carried out in the absence of diatomite, this value was increased to 33.73nm. The use of diatomite also promoted an increase of the transformation temperature of the crystalline phase anatase to rutile for the TiO. The as-prepared TiO/diatomite composite exhibited high photocatalytic activity (96.0% for 0.5h UV-light irradiation) for the degradation of RhB from wastewater as a result of its unique porous structure and optimum TiO loading. In addition, it can be easily separated from suspension and possess a good durability. This hybrid material holds great promise in the engineering field for the environmental remediation

Predicting Disease-Related Genes Using Integrated Biomedical Networks

Background: Identifying the genes associated to human diseases is crucial for disease diagnosis and drug design. Computational approaches, esp. the network-based approaches, have been recently developed to identify disease-related genes effectively from the existing biomedical networks. Meanwhile, the advance in biotechnology enables researchers to produce multi-omics data, enriching our understanding on human diseases, and revealing the complex relationships between genes and diseases. However, none of the existing computational approaches is able to integrate the huge amount of omics data into a weighted integrated network and utilize it to enhance disease related gene discovery. Results: We propose a new network-based disease gene prediction method called SLN-SRW (Simplified Laplacian Normalization-Supervised Random Walk) to generate and model the edge weights of a new biomedical network that integrates biomedical data from heterogeneous sources, thus far enhancing the disease related gene discovery. Conclusions: The experiment results show that SLN-SRW significantly improves the performance of disease gene prediction on both the real and the synthetic data sets

Relationship Between Alzheimer’s Disease and the Immune System: A Meta-Analysis of Differentially Expressed Genes

Alzheimer’s disease (AD), a neurodegenerative diseases (neuro-diseases) which is prevalent in the elderly and seriously affects the lives of individuals. Many studies have discussed the relationship between immune system and AD pathogenesis. Here, the meta-analysis of differentially expressed (DE) genes based on microarray data was conducted to study the association between AD and immune system. 9519 target genes of hippocampus in 146 subjects (73 AD cases and 73 controls) from 4 microarray data sets were compiled and DE genes with p < 1.00E - 04 were selected to conduct the pathway-analysis. The results indicated that the DE genes were significantly enriched in the neuro-diseases as well as the immune system pathways

Characterization and improved solar light activity of vanadium doped diatomite hybrid catalysts

V-doped TiO/diatomite composite photocatalysts with different vanadium concentrations were synthesized by a modified sol-gel method. The diatomite was responsible for the well dispersion of TiO nanoparticles on the matrix and consequently inhibited the agglomeration. V-TiO/diatomite hybrids showed red shift in TiO absorption edge with enhanced absorption intensity. Most importantly, the dopant energy levels were formed in the TiO bandgap due to V ions substituted to Ti sites. The 0.5% V-TiO/diatomite photocatalyst displayed narrower bandgap (2.95eV) compared to undoped sample (3.13eV) and other doped samples (3.05eV) with higher doping concentration. The photocatalytic activities of V doped TiO/diatomite samples for the degradation of Rhodamine B under stimulated solar light illumination were significantly improved compared with the undoped sample. In our case, V ions incorporated in TiO lattice were responsible for increased visible-light absorption and electron transfer to oxygen molecules adsorbed on the surface of TiO to produce superoxide radicals O, while V species presented on the surface of TiO particles in the form of VO contributed to e-h separation. In addition, due to the combination of diatomite as support, this hybrid photocatalyst could be separated from solution quickly by natural settlement and exhibited good reusability

Enhanced photocatalytic properties of reusable TiO2-loaded natural porous minerals in dye wastewater purification

Diatomite-based recyclable photocatalysts containing single lanthanide doped TiO nanoparticles (NPs) were synthesized by using simple sol–gel method. Photocatalytic activities of the prepared Ce- or La- single doped TiO/diatomite catalysts were estimated by the degradation of Rhodamine B (RhB) under simulated sunlight irradiation. The XRD and Raman spectra shown only anatase phase of TiO for the un-doped and Ce-doped samples. The TEM images revealed uniform distribution of TiO NPs on the matrix, indicating that diatomite played an important role to prevent the agglomeration of TiO NPs. Ce-TiO/diatomite showed a red shift in UV–visible light absorption edge with enhanced absorption intensity than un-doped sample, whereas La-TiO/diatomite showed a blue shift. The bandgap energy of 1.5%-Ce doped sample is as low as 2.75 eV. The XPS spectra showed the presence of both Ce and Ce oxidation states for Ce dopant. The photoluminescence spectra of the Ce-doped samples showed first decrease in the recombination centers with the maximum decrease for 1.5%-Ce doped sample and then started increase with the increasing Ce in the samples. As compared to the La-doped samples, a desired behavior was observed for the Ce-doped hybrid due to the redox Ce/Ce pairs acting as electron scavengers and localized unoccupied Ce 4f level narrowing the band gap. The incorporation with diatomite as support of TiO nanoparticles is contributed for the improved reusability and also gives a promising strategy to enable the application of nano-photocatalysts in a real wastewater remediation treatment