Deformation and failure of stratified weak roof strata of longwall roadway

A comprehensive underground monitoring was conducted in a coal mine. The purpose of this research was to clarify the deformation and failure behavior of stratified weak roof strata of longwall roadway in adverse ground conditions. The field investigation incorporating a range of geotechnical instrumentation was conducted over a period of time ever since the formation of opening the site was buried into the goaf of a retreating longwall panel. The roof layer deformation and failure characteristics associated with the three stages of heading development, after development and before extraction, as well as after longwall extraction were identified on the basis of field investigation and analytical study, the results clearly demonstrated that how the roof deformation and failure progress were strongly related to these three stages of the mining activities mentioned.     

Analysis of CVC roll contour and determination of roll crown

Mathematical analysis of continuous variable crown (CVC) roll contour used in CSP production line was conducted and the roll contour function of CVC roll was obtained. The validation with actual CVC roll contour shows that the calculation values of the roll contour function and the actual roll contour parameters given by equipment provider are the same, which proves that the roll contour function of CVC rolls given in this article is correct. The nonlinear relationship between the roll crown of CVC rolls and roll shift amounts was deduced. The concept of crown extremum was given.     

Abrasive wear behaviors of high velocity arc sprayed iron aluminum composite coatings

The High Velocity Arc Spraying (HVAS) technology was used to prepare Fe-Al composite coatings by the adding of different elements into cored wires to obtain different Fe-Al coatings. The added compounds do great effect on the properties of the composite coatings. The microstructures and abrasive wear performances of the coatings were assessed by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and THT07-135 high temperature wear equipment. It was found that the adding of Cr₃C₂ can greatly increase the room temperature wear behavior, and Fe-Al/WC coatings have adapting periods at the beginning of wear experiment. With the rise of temperature, the wear resistance of Fe-Al/Cr₃C₂ coatings becomes bad from room temperature to 250°C, and then stable from 250°C to 550°C; the wear resistance of Fe-Al/WC becomes well with the rise of temperature. The adding of Cr and Ni can also improve wear performances of Fe-Al composite coatings.     

Underground Pipeline Surveillance with an Algorithm Based on Statistical Time-Frequency Acoustic Features

Underground pipeline networks suffer from severe damage by earth-moving devices due to rapid urbanization. Thus, designing a round-the-clock intelligent surveillance system has become crucial and urgent. In this study, we develop an acoustic signal-based excavation device recognition system for underground pipeline protection.The front-end hardware system is equipped with an acoustic sensor array, an Analog-to-Digital Converter(ADC)module(ADS1274), and an industrial processor Advanced RISC Machi...     

Advanced Process and Electron Device Technology

This article reviews advanced process and electron device technology of integrated circuits, including recent featuring progress and potential solutions for future development. In 5 years, for pushing the performance of fin field-effect transistors(FinFET) to its limitations, several processes and device boosters are provided. Then, the three-dimensional(3 D) integration schemes with alternative materials and device architectures will pave paths for future technology evolution. Finally, it could...     

CDCAT: A Multi-Language Cross-Document Entity and Event Coreference Annotation Tool

A tool for the manual annotation of cross-document entity and event coreferences that helps annotators to label mention coreference relations in text is essential for the annotation of coreference corpora. To the best of our knowledge, CROss-document Main Events and entities Recognition(CROMER) is the only open-source manual annotation tool available for cross-document entity and event coreferences. However, CROMER lacks multi-language support and extensibility. Moreover, to label cross-document...     

Design and implementation of near-memory computing array architecture based on shared buffer

Deep learning algorithms have been widely used in computer vision, natural language processing and other fields. However, due to the ever-increasing scale of the deep learning model, the requirements for storage and computing performance are getting higher and higher, and the processors based on the von Neumann architecture have gradually exposed significant shortcomings such as consumption and long latency. In order to alleviate this problem, large-scale processing systems are shifting from a t...     

Single-factor analysis and interaction terms on the mechanical and microscopic properties of cemented aeolian sand backfill

The use of aeolian sand (AS) as an aggregate to prepare coal mine cemented filling materials can resolve the problems of gangue shortage and excessive AS deposits.Owing to the lack of research on the mechanism of cemented AS backfill (CASB),the response surface method (RSM) was adopted in this study to analyze the influence of ordinary Portland cement (PO) content (x₁),fly ash (FA)–AS (FA–AS) ratio (x₂),and concentration (x₃) on the mechanical and microscopic pro...     

Effects of vanadate on the activities of mice glucokinase and hexokinase

This study aimed at acquiring knowledge on the hypoglycemic mechanisms of sodium metavanadate (SMV) showed that the liver glucokinase and muscle hexokinase activities increased rapidly after oral SMV was given, and that the blood glucose level was correlated closely with the activities of the two enzymes but not with the insulin level; which indicated that SMV could improve the altered glucose phosphorylation in diabetic mice independently of stimulating insulin secretion. This was probably one of the mechanisms of hypoglycemic effects of SMV.