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In wide-angle X-ray scattering (WAXS) experiments, the use of a one-dimensional arc detector can effectively expand the angle range of collected diffraction or scattering signals. In practice, the relative positions between the centers of arc detector, sample and beam spot may overlap or misalign. Therefore, it is necessary to calibrate the instrument parameters and detection angle of the arc detector. The calibration is routinely performed by standard samples. In this contribution, the equations for angle calibration and error evaluation are constructed based on three standard diffraction peaks, and the corresponding simulation and experiment are performed to verify the feasibility of the calibration. The results indicate that the larger the coverage and the more uniform the dispersion of the three standard diffraction peaks distributed on the detector, the smaller the calibration error. [ABSTRACT FROM AUTHOR]

This paper is based on the reconstruction project of south section of National Highway No.310 (Xingyang Qiaolou-Cuimiao section) in Zhengzhou of National Highway No.234, which involves the construction of an overpass for National Highway No.234 to cross over Zhengzhou- Xi'an High-speed Railway. The main focus of this paper is to analyze the key and difficult points in the design of the foreign object intrusion monitoring system for the project and propose solutions. This project is the first foreign object intrusion monitoring system design for the operating high-speed railway overpass within the jurisdiction of Zhengzhou Bureau, providing reference and experience for the design and construction of similar projects in Henan and even throughout the whole country of China in the future. [ABSTRACT FROM AUTHOR]

Interaction is critical for successful teaching and learning in a virtual learning environment (VLE). This paper presents a web-based interaction-aware VLE--WebIntera-classroom--which aims to augment learning interactions by increasing the learner-to-content and learner-to-instructor interactions. We design a ubiquitous interactive interface that integrates a pen-and-paper interface with a web-based whiteboard to promote effective learner-to-content interactions. We develop a learning analytics tool that instantly shows learners' learning interactions, with which instructors can supervise learner-to-instructor interactions. We implement a high-granularity Learning Analytics Engine (hgLAE) to broadcast, record and play a lecture recording. The hgLAE identifies hotspots in a lecture recording and raises students' awareness of the hotspots when they watch the recording. WebIntera-classroom has been deployed in 11 universities in China. The system obtained high satisfaction in the questionnaires (N = 464) and face-to-face interviews (N = 60) conducted with the users from China Jiliang University. We compared the students' performance, respectively, achieved in traditional classroom and in WebIntera-classroom at China Jiliang University during 2012-2013. The result demonstrates that the students could gain performance improvement by using WebIntera-classroom.

Based on the 5G renovation project for public network coverage in tunnels of the Shandong section of Beijing-Shanghai High-speed Railway, this paper studies the scheme for such issues as leakage cable selection, link budget, power supply, and transmission. After analyzing the existing situation of the public network equipment, it proposes the integrated renovation of the existing public network equipment and its supporting power supply and transmission optical cables, which provides design experience for similar projects in the future. [ABSTRACT FROM AUTHOR]

In small angle X-ray scattering (SAXS) experiments, there exists an optimal sample thickness to obtain measurements with the maximum signal-to-noise ratio and best statistics. In practice, the sample thickness may deviate from the optimal value due to certain conditions. For thick samples, smearing may appear for the scattering data and an equivalent sample position to compute the scattering vector. Calculations show that the sample thickness has a similar effect on SAXS for monodisperse and polydisperse systems. Qualitative and quantitative analysis has been performed to determine the deviation of equivalent sample position from the irradiated sample center. [ABSTRACT FROM AUTHOR]

Polyacrylonitrile (PAN) based carbon fibers possess high performance and wide applications. Preoxidation, as one of the crucial steps in the preparation of carbon fibers, refers to the process in which the polyacrylonitrile fibers are oxidized to form the embryo of carbon lamellar structure below 300 °C in air. Synchrotron radiation wide angle X-ray scattering (WAXS) is an ideal method for the in-situ study of the preoxidation of fibers. However, an appropriate heating furnace is required to obtain anisotropic two-dimensional scattering/diffraction images. This paper reports the development of a small, simple furnace (300 °C) with flared mouth/outlet (90°) and a fiber sample bracket. The preoxidation of polyacrylonitrile fibers in the furnace was monitored in situ by synchrotron radiation wide angle X-ray scattering and the serviceability of the furnace was verified. [ABSTRACT FROM AUTHOR]

Wide-angle X-ray scattering (WAXS) is routinely used to characterize the ordered structure in materials. The measured angles are generally calibrated by using standard samples with several diffraction peaks. When a WAXS instrument uses a one-dimensional linear detector, which is tilted to the direct beam, the angle calibrations need three standard diffraction peaks. This contribution presents the corresponding analytical solution of the calibration equations and error estimation matrix and performs error simulation and experimental verification. The results show that the selected three standard diffraction peaks should uniformly span and widely cover the detector to reduce the error of angle calibration. [ABSTRACT FROM AUTHOR]

Interaction is critical for successful teaching and learning in a virtual learning environment (VLE). This paper presents a web-based interaction-aware VLE – WebIntera-classroom – which aims to augment learning interactions by increasing the learner-to-content and learner-to-instructor interactions. We design a ubiquitous interactive interface that integrates a pen-and-paper interface with a web-based whiteboard to promote effective learner-to-content interactions. We develop a learning analytics tool that instantly shows learners’ learning interactions, with which instructors can supervise learner-to-instructor interactions. We implement a high-granularity Learning Analytics Engine (hgLAE) to broadcast, record and play a lecture recording. The hgLAE identifies hotspots in a lecture recording and raises students’ awareness of the hotspots when they watch the recording. WebIntera-classroom has been deployed in 11 universities in China. The system obtained high satisfaction in the questionnaires (N = 464) and face-to-face interviews (N = 60) conducted with the users from China Jiliang University. We compared the students’ performance, respectively, achieved in traditional classroom and in WebIntera-classroom at China Jiliang University during 2012–2013. The result demonstrates that the students could gain performance improvement by using WebIntera-classroom. [ABSTRACT FROM AUTHOR]