Key Technology of Real-Time Road Navigation Method Based on Intelligent Data Research

The effect of traffic flow prediction plays an important role in routing selection. Traditional traffic flow forecasting methods mainly include linear, nonlinear, neural network, and Time Series Analysis method. However, all of them have some shortcomings. This paper analyzes the existing algorithms on traffic flow prediction and characteristics of city traffic flow and proposes a road traffic flow prediction method based on transfer probability. This method first analyzes the transfer probability of upstream of the target road and then makes the prediction of the traffic flow at the next time by using the traffic flow equation. Newton Interior-Point Method is used to obtain the optimal value of parameters. Finally, it uses the proposed model to predict the traffic flow at the next time. By comparing the existing prediction methods, the proposed model has proven to have good performance. It can fast get the optimal value of parameters faster and has higher prediction accuracy, which can be used to make real-time traffic flow prediction

Towards Accurate Predictions and Mechanistic Understanding of the Catalytic Activity of Transition Metal Oxides

<p>The development of active and inexpensive catalysts is vital for progress in technologies related to efficient energy generation, storage, and utilization. Transition metal oxides (TMOs) make up a significant fraction of current state-of-the-art catalysts for these technologies. Density functional theory (DFT), the workhorse for computational chemistry and catalysis, can calculate the activity of catalysts, provide synthesis targets, and accelerate the discovery of active and cheap TMO catalysts. This dissertation develops DFT methods for accurately calculating and understanding the catalytic activity of TMOs. Known electron self-interaction errors in TMO bulk oxidation energies implies reactions energies on TMO surfaces should contain similar errors. The linear response U, proposed to correct self-interaction error, was evaluated as a method for obtaining more accurate TMO reaction energies. Application of the linear response U gave unprecedented improvement in TMO oxidation energies, mixed improvement in TMO formation energies, and improved trends in TMO surface reactivity. These results motivate the continued development of linear response U for bulk and surface calculations. The calculated electronic structure of a catalyst can be used to relate its structure and composition to its activity. Physical and chemical complexities of TMOs hinder development of useful and elucidative electronic structure models. Using the understanding of adsorption on metals as a foundation, a number of correlations between the calculated electronic structure and adsorption energy were found on TMO surfaces. These correlations led to structure-function relationships of binary, ternary, and polymorph TMOs. Methods and results used provides research directions on the continued search for new transition metal compound catalysts.</p

A Linear Response DFT+<i>U</i> Study of Trends in the Oxygen Evolution Activity of Transition Metal Rutile Dioxides

There are known errors in oxidation energies of transition metal oxides caused by an improper treatment of their d-electrons. The Hubbard <i>U</i> is the computationally cheapest addition one can use to capture correct reaction energies, but the specific Hubbard <i>U</i> oftentimes must be empirically determined only when suitable experimental data exist. We evaluated the effect of adding a calculated, linear response <i>U</i> on the predicted adsorption energies, scaling relationships, and activity trends with respect to the oxygen evolution reaction for a set of transition metal dioxides. We find that applying a <i>U</i> greater than zero always causes adsorption energies to be more endothermic. Furthermore, the addition of the Hubbard <i>U</i> greater than zero does not break scaling relationships established without the Hubbard <i>U</i>. The addition of the calculated linear response <i>U</i> value produces shifts of different systems along the activity volcano that results in improved activity trends when compared with experimental results

Correction: Identification of soil P fractions that are associated with P loss from surface runoff under various cropping systems and fertilizer rates on sloped farmland.

[This corrects the article DOI: 10.1371/journal.pone.0179275.]

Supporting data for: A linear response, DFT+U study of trends in the oxygen evolution activity of transition metal rutile dioxides

<p>This directory contains all of the finished calculations required for fully analysis of the paper "A linear response, DFT+U study of trends in the oxygen evolution activity of transition metal rutile dioxides" by Zhongnan Xu, Jan Rossmeisl, and John R Kitchin. To use this repository, download the supporting information file and run the scripts present in either 'supporting-information.pdf' or 'supporting-information.org'.</p> <p>The is the release of the supporting data before the first submission to the first journal.</p

Identification of soil P fractions that are associated with P loss from surface runoff under various cropping systems and fertilizer rates on sloped farmland.

Soil phosphorus (P) fractions and runoff P concentration were measured to understand the fate of soil P entering surface runoff water during summer cropping season of different double cropping systems under two fertilizer regimes. The dominant form of runoff P was particulate P (PP). Runoff total P (TP) was higher at the vegetative growth stage and lower at the crop reproductive stage. TP and PP were derived mainly from soil Olsen-P, Al-P and Fe-P and amounts increased with sediment content in runoff water. Runoff P discharge was closely related to the changes in soil P forms. Soil Olsen-P, mainly consisting of some Ca2-P and Al-P, was increased by elevating fertilizer rate. Along with crop growth, there were active interconversions among Olsen-P, Org-P, Fe-P and O-Al-P in the soil, and some available P converted into Ca10-P, with O-Fe-P possibly being a transitional form for this conversion. The oilseed rape/corn system had less runoff TP at the early stage, and wheat/sweet potato system had a lower runoff P at the late stage. Intercropping corn with sweet potato in the field with oilseed rape as a previous crop may be helpful for alleviating runoff P load during the summer in this region

First-Principles Investigation of the Epitaxial Stabilization of Oxide Polymorphs: TiO₂ on (Sr,Ba)TiO₃

Metastable polymorphs, many of which have never been fabricated, have been predicted to exhibit interesting and technologically relevant properties. Epitaxial synthesis is a powerful structure-directing method that can produce metastable polymorphs but is typically done in a trial and error fashion. Unfortunately, the relevant thermodynamic terms governing epitaxial synthesis of new materials are unknown. Accurate calculation of the relevant thermodynamic terms and their incorporation into predictive models would accelerate the synthesis of metastable polymorphs by identifying thermodynamically favorable paths. Using density functional theory with three different functionals, we computed several relevant terms for TiO₂ anatase (A) and rutile (R) film growth on low-index surfaces of SrTiO₃ (STO) and BaTiO₃ (BTO) cubic perovskites. After identifying potential coherent epitaxial interfaces based on experimental observations, the volumetric formation, volumetric strain, and areal substrate–film interface energies were calculated for (001)_A∥(001)_(S/B)TO, (102)_A∥(011)_(S/B)TO, (100)_R∥(111)_(S/B)TO, and (112)_A∥(111)_(S/B)TO coherent interfaces. These terms were integrated into a standard model of epitaxial nucleation, and the results yielded reasonable agreement between experimental observations and DFT predictions of the preferred epitaxial polymorph. Predicted trends in epitaxial stability were essentially independent of the three functionals used in the calculations. These results are discussed in light of their promise that DFT-informed epitaxial film growth can accelerate fabrication of new polymorphs. These results also validate the recently proposed 20 kJ/mol stability window for predicting which polymorphs could be epitaxially stabilized