A Study on Regional E-commerce Development in China and Its Influencing Factors

This paper defines the concept of regional e-commerce by analyzing the literature. According to the definition, this paper extracted the core indicators of regional e-commerce development, and used the principal component analysis to evaluate the development level of regional e-commerce. Finally, this paper analyzes the impact factors of regional e-commerce development from qualitative and quantitative perspective and puts forward relevant hypotheses. Regression analysis is used in this paper to validate the hypothesis in the analysis of the influencing factors of regional E-commerce. The empirical results has showed that the industrial structure, network coverage, logistics infrastructure are key factors of regional e-commerce development

Screening Arabidopsis accessions for alkaline stress tolerance

RESEARCH QUESTIONS 1. Will there be differences between Arabidopsis accessions for alkaline stress tolerance in potting mix growth conditions? 2. Will there be differences for fluorescent concentration between inside and outside roots in hydroponic system? 3. Will there be differences for fluorescent concentration between different Arabidopsis accessions in hydroponic system

Screening Arabidopsis accessions for alkaline stress tolerance

RESEARCH QUESTIONS 1. Will there be differences between Arabidopsis accessions for alkaline stress tolerance in potting mix growth conditions? 2. Will there be differences for fluorescent concentration between inside and outside roots in hydroponic system? 3. Will there be differences for fluorescent concentration between different Arabidopsis accessions in hydroponic system

Amyloid precursor protein modulates β-catenin degradation

<p>Abstract</p> <p>Background</p> <p>The amyloid precursor protein (APP) is genetically associated with Alzheimer's disease (AD). Elucidating the function of APP should help understand AD pathogenesis and provide insights into therapeutic designs against this devastating neurodegenerative disease.</p> <p>Results</p> <p>We demonstrate that APP expression in primary neurons induces β-catenin phosphorylation at Ser₃₃, Ser₃₇, and Thr₄₁(S33/37/T41) residues, which is a prerequisite for β-catenin ubiquitinylation and proteasomal degradation. APP-induced phosphorylation of β-catenin resulted in the reduction of total β-catenin levels, suggesting that APP expression promotes β-catenin degradation. In contrast, treatment of neurons with APP siRNAs increased total β-catenin levels and decreased β-catenin phosphorylation at residues S33/37/T41. Further, β-catenin was dramatically increased in hippocampal CA1 pyramidal cells from APP knockout animals. Acute expression of wild type APP or of familial AD APP mutants in primary neurons downregulated β-catenin in membrane and cytosolic fractions, and did not appear to affect nuclear β-catenin or β-catenin-dependent transcription. Conversely, in APP knockout CA1 pyramidal cells, accumulation of β-catenin was associated with the upregulation of cyclin D1, a downstream target of β-catenin signaling. Together, these data establish that APP downregulates β-catenin and suggest a role for APP in sustaining neuronal function by preventing cell cycle reactivation and maintaining synaptic integrity.</p> <p>Conclusion</p> <p>We have provided strong evidence that APP modulates β-catenin degradation <it>in vitro </it>and <it>in vivo</it>. Future studies may investigate whether APP processing is necessary for β-catenin downregulation, and determine if excessive APP expression contributes to AD pathogenesis through abnormal β-catenin downregulation.</p

Operation optimisation study for CCGT power plant.

A major concern for the power generation industry is to obtain a maximum economic benefit without over-consuming the remaining life of the gas turbine hot section. This study explored a methodology to support decision making for operational optimisation of a combined cycle gas turbine (CCGT) power plant. There is no published algorithm for modelling a parallel dual pressure, once-through steam generator (OTSG), nor any proposed method for OTSG degradation diagnosis and how the degradation affects OTSG performance. What is more, few publications were found for optimisation existing power plant operation considering gas turbine creep life. This study presents a new thermodynamic algorithm to simulate the thermodynamic performance of parallel dual pressure OTSG. In this study, a novel gas path diagnostic method for an OTSG based on the Newton-Raphson method was developed to predict the OTSG degradation caused by fouling. A daily operation decision support platform for this existing power plant is proposed that models CCGT performance, creep life, emissions, economics, and provides a basis for decision-making based optimised results. The OTSG performance model is applied to an OTSG operating in a CCGT power plant at Manx Utilities on the Isle of Man, United Kingdom to demonstrate the effectiveness of the simulation method. A comparison between predicted OTSG performance and OTSG field data showed that the proposed model offers good prediction accuracy when simulating OTSG performance for both design and off-design points. The OTSG diagnostic system was applied to a model OTSG to test its effectiveness. The impact of measurement noise on the diagnostic accuracy was also analysed and discussed. A comparison between predicted and implanted degradation of a model OTSG demonstrated that the results were satisfactory, and the method is promising. Moreover, the diagnostic analysis of an OTSG based on real measurement has further proved that the proposed diagnostic method works well. This simulation will recommend to the plant operator optimal operation schedules taking into consideration thermo-economics and lifing, under conditions of variation of power demand, electricity price, ambient conditions and gas turbine engine health states. It will suggest the more severely degraded engine should run at a relatively lower power setting to decrease creep life consumption. The established power plant optimisation framework will assist power plant operators to decide the total power output and power split between generators based on an optimisation system that considers both immediate economic benefit and life considerations. It will help existing power plant to adjust daily operation to achieve better thermoeconomic and lifing benefits. The outcome of this research will be useful for industrial CCGT power generation.PhD in Aerospac

Assessment of SAPRC07 with Updated Isoprene Oxidation Chemistry against Outdoor Chamber Experiments

Isoprene, the most emitted non-methane hydrocarbon, is known to influence ozone (O3) formation in urban areas rich with biogenic emissions. To keep up with the recent advance on isoprene oxidation chemistry including the identification of isoprene epoxydiols (IEPOX) as a precursor to secondary organic aerosol (SOA), Xie et al. (2013) updated the SAPRC (Statewide Air Pollution Research Center)-07 chemical mechanism. It is currently unknown how the Xie modification of SAPRC07T impacts the ability of the model to predict O3. In this project we will evaluate the Xie mechanism with simulations of 24 isoprene experiments from the UNC gas-phase chamber. Our results suggest that the new mechanism increases NOX (nitrogen oxides) inter-conversion and produces more O3 than SAPRC07 for all experiments. In lower NOX experiments, the new mechanism worsens O3 performance towards the wrong direction, increasing bias from 8.9% to 15.8%. We found increased NOX recycling from NOZ (oxidized NO2) accounts for that. These results underline the importance of further studies on characterizing the NOX recycling rate from isoprene nitrates.Master of Science in Environmental Engineerin