56 research outputs found

    Consumer Confidence, News and Consumption Stimulation

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    In the Chinese urban data, there is a stronger relationship between consumer behavior (measured by consumption income ratio or cy ratio) and consumer confidence (measured by Consumer Confidence Index or CCI), which implies expectation about the future plays an important role in domestic demand. In our paper, a structural VAR method (based on Beaudry&Portier 2006 AER) is employed to identify the news shock about three markets including housing, education and medical care. We also extract the components in CCI about news shocks for those three sectors. After that, we conduct regression on cy ratio against those components extracted from CCI, and find that the expectation on housing accounts more importance in consumption, education takes a second place and medical care has little effect.News Driven Expectation; Chinese Consumption Behavior; Structural VAR

    Analysis of Red-Light Violation Behavior of Pedestrian Two-Stage Crossing at a Signalized Intersection

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    Studying pedestrians’ twice-crossing behavior is of great significance to enhance safety and efficiency for pedestrians at signalized intersections. However, researchers have paid little attention to analyze and model pedestrians’ red-light running behavior on a two-stage crossing at signalized intersections. This paper focuses on analyzing the characteristics of pedestrian red-light violation behavior at the two stages, including the time distribution of violation behavior, the consistency of violation behavior, and the violation behavior in group.  A goal-oriented and time-driven red-light violation behavior model was proposed for pedestrian two-stage crossing. A video-recording method was used to collect field data, and the results show that pedestrians in the two directions present different red-light violation behaviors in time selection and violation count, as well as, pedestrians in the two stages of a direction present different red-light violation behaviors in time selection. The main reasons leading to the phenomena were analyzed, regarding from people’s cognitive psychology and visual perception. The results also show that the proposed model is effective in simulating pedestrian red-light violation behavior of twice crossing. This research provides a theoretical basis for optimizing signal timing, improving pedestrian safety and developing user-friendly transportation system

    Analysis of Route Choice for Pedestrian Two-Stage Crossing at a Signalized Intersection

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    Studying pedestrians’ twice-crossing behavior is of great significance to enhance safety and efficiency for pedestrians at signalized intersections. However, limited attention has been paid to analyze and model pedestrians’ behavior patterns of twice crossing. The purpose of this paper is to determine pedestrians' route choices for twice crossing at a signalized intersection, focusing on the waiting position (to cross the street) and walking route. A goal-oriented and time-driven model was proposed to analyze pedestrians’ twice-crossing behavior at signalized intersections, where the two directions have different pedestrian signal timing. A video-recording method was used to collect field data in order to obtain pedestrian preferences in choosing a walking route. It was found that pedestrians in the two directions present different preferences toward walking route, in waiting position, directional change and route type. The results showed that the proposed model is effective in simulating pedestrian route-choice behavior of twice crossing. This research provides a theoretical basis for identifying pedestrian movement intention, optimizing signal timing, and improving pedestrian infrastructure at signalized intersections.

    Metal-bonded perovskite lead hydride with phonon-mediated superconductivity up to 46 K under atmospheric pressure

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    In the search for high-temperature superconductivity in hydrides, a plethora of multi-hydrogen superconductors have been theoretically predicted, and some have been synthesized experimentally under ultrahigh pressures of several hundred GPa. However, the impracticality of these high-pressure methods has been a persistent issue. In response, we propose a new approach to achieve high-temperature superconductivity under atmospheric pressure by implanting hydrogen into lead to create a stable few-hydrogen metal-bonded perovskite, Pb4_4H. This approach diverges from the popular design methodology of multi-hydrogen covalent high critical temperature (TcT_c) superconductors under ultrahigh pressure. By solving the anisotropic Migdal-Eliashberg (ME) equations, we demonstrate that perovskite Pb4_4H is a typical phonon-mediated superconductor with a TcT_c of 46 K, which is six times higher than that of bulk Pb (7.22 K) and higher than that of MgB2_2 (39 K). The high TcT_c can be attributed to the strong electron-phonon coupling (EPC) strength of 2.45, which arises from hydrogen implantation in lead that induces several high-frequency optical phonon modes with a relatively large phonon linewidth resulting from H atom vibration. The metallic-bonding in perovskite Pb4_4H not only improves the structural stability but also guarantees better ductility than the widely investigated multi-hydrogen, iron-based, and cuprate superconductors. These results suggest that there is potential for the exploration of new high-temperature superconductors under atmospheric pressure and may reignite interest in their experimental synthesis soon.Comment: 6 pages, 4 figure

    Approximate Multi-Degree Reduction of SG-BĂ©zier Curves Using the Grey Wolf Optimizer Algorithm

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    SG-Bézier curves have become a useful tool for shape design and geometric representation in computer aided design (CAD), owed to their good geometric properties, e.g., symmetry and convex hull property. Aiming at the problem of approximate degree reduction of SG-Bézier curves, a method is proposed to reduce the n-th SG-Bézier curves to m-th (m < n) SG-Bézier curves. Starting from the idea of grey wolf optimizer (GWO) and combining the geometric properties of SG-Bézier curves, this method converts the problem of multi-degree reduction of SG-Bézier curves into solving an optimization problem. By choosing the fitness function, the approximate multi-degree reduction of SG-Bézier curves with adjustable shape parameters is realized under unrestricted and corner interpolation constraints. At the same time, some concrete examples of degree reduction and its errors are given. The results show that this method not only achieves good degree reduction effect, but is also easy to implement and has high accuracy

    Exploration and Practice of Customized Agricultural Meteorological Service Based on Short Message Service

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    On the basis of the analysis of main problems existing in current agricultural meteorological service in China, for the purpose of exploring a solution to the “last kilometer” problem in rural meteorological service, this article designed four short message service products with the business brand name “meteorology for agricultural condition”, including “weather prediction for farming season”, “weather forecast for farming”, “weather alert”, and ”meteorological hazards of agriculture”. By taking advantage of telecom operators’ market, these products have been spread to more than 100 million rural mobile phone users and widely welcomed. They also contributed enormously to disaster prevention and peasants' income growth, and achieved good social and economic benefits

    Mechanical characteristics of a tunnel boring machine cutterhead during rock breaking: Physical model tests and transient dynamic analysis

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    During tunnel excavation using a tunnel boring machine (TBM), the interaction between the cutter and the rock causes the cutterhead to generate abrupt vibrations, which could lead to engineering problems, such as bearing seal failure and even cutterhead cracking. In this study, large-scale physical model tests with various cutter spacings were performed to study the vibration and load characteristics of the cutterhead during the rock-breaking process. Through a TBM modal comprehensive test bench, the real-time acceleration of the cutterhead was obtained using a monitoring system. The test results showed that the complete time-domain curves were stepped and periodic. When the cutterhead was stuck or rock peeled off during the excavation, the monitoring curves showed abrupt vibrations, which were mainly concentrated at 0–3 Hz and were typical low-frequency vibrations. Taking measured data as the driving parameter, the real-time mechanical characteristics of the cutterhead were determined through transient dynamic analysis. Numerical simulation results showed that the vibration trend during excavation was the superposition of random vibrations generated by rock breaking and tunneling without rock cutting. During the tunneling process, the wear of the edge cutters should be highlighted in actual construction. The related methods and results can provide an essential reference for the selection of cutterheads

    Influence Factors and Elimination on Iron Content Using ICP-AES Method in Oilfield Produced Water

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    ICP-AES method can be used to determine multiple metallic elements simultaneously, and has the advantages of high sensitivity, good repeatability and high accuracy. In the paper, the detection limit of iron content was determined by stepwise dilution method. The influence of the cationic concentration on the determination of iron element was studied, and the matrix matching method was proposed to eliminate the influence. The results show that, the determination limit of Iron element is 0.01 mg·L-1. Because the other cationic content is several times or even tens of times as much as iron ions, it has a great influence on the determination results of Iron element. The effects of cationic concentration can be effectively eliminated by establishing a standard curve using matrix matching. After digestion pretreatment on the oil and gas field produce water, The standard adding recovery rate was between 95% and 105%, and the RSD is less than 4%. Compare this method with o-phenanthroline spectrophotometry, its relative error is within 5%. Therefore, ICP-AES method can fully meet the requirements of determination of iron content in oil field produce water, and greatly improves the efficiency and accuracy of the laboratory analysis of oil and as field wastewater

    Full-Length Transcriptome of <i>Camellia japonica</i> (Naidong) Reveals Molecular Characteristics in Drought Stress

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    Camellia japonica (Naidong), a rare temperate arbor in the genus Camellia, is an ornamental plant with high economic value. To understand transcriptional changes of the drought response in C. japonica, a comparative transcriptome analysis of C. japonica (Naidong) was conducted at two drought stages (0 and 20 DAF) based on the PacBio platform. The results showed significant differences in 265 genes and 3383 lncRNAs. Of these, 150 were upregulated and 115 were downregulated. Functional analysis revealed the involvement of distinct genes in 43 pathways. The biosynthesis of amino acids and the circadian rhythm of the plant were significantly enriched, with a significant change in CjGST potentially playing an important role under drought stress. In addition, three differential protein interaction network modules composed of 45 differentially expressed genes were predicted, which involved E3 ubiquitin ligases and threonine synthetic proteins. Moreover, a transient expression experiment demonstrated that overexpression of CjGST1 in camellia leaves significantly increased leaf area compared to wild variants under drought stress, resulting in higher drought resistance. These findings provide a valuable resource for studying the genus Camellia while shedding new light on the molecular mechanisms of drought stress
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