bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diffractive optical elements for multiplexing structured laser beams
Authors: Kazanskiy N.L. , Khonina S.N. , Karpeev S.V. , Porfirev A.P. 
Published: July 2020

Abstract
We consider methods for obtaining a multitude of structured laser beams (multiplexing) from an illuminating beam (both structured and unstructured) with the help of diffractive optical elements (DOEs). An approach of ‘intelligent multiplexing’ is proposed to describe and develop the methods. A DOE is calculated that forms a set of five diffraction orders located in a line. An example of focusing a set of doughnut-shaped azimuthally polarised laser beams using a diffraction beam splitter is presented. Efficient multiplexing of first-order vortex beams in a two-dimensional region is implemented by a two-dimensional diffraction grating. An approach is proposed and realised in which the transmission functions of a two-dimensional diffraction beam splitter and the elements forming structured laser beams with specified parameters are combined into the transmission function of one element. Such DOEs can be used in optical communication systems for encoding and decoding data. The possibility of using binary curved fork-shaped gratings for the formation of doughnut-shaped three-dimensional vortex beams, which are detected outside the focal plane, is demonstrated. This approach provides additional advantages for safe data transmission; it can be used in laser processing of materials and in laser manipulation applications.
Guiding towards register awarenessin an undergraduate EFL curriculumin Italy
Authors: Miller Donna R. , Luporini Antonella 
Published: July 2020

AbstractThis contribution adds to ever-growing research on ‘pedagogical stylistics’, (e.g.,Burke et al. 2012). We present a case study describing a register approach to teaching literature, or verbal art (Hasan 1985/1989), to undergraduate EFL students in a Systemic Functional Grammar (FG)-based perspective (Halliday & Matthiessen 2004). Our research is guided by two main goals: enhancing the students’ sensitivity to the peculiar functions of language in literature, as part of a wider curriculum on teaching register awareness, and setting up good practices to monitor and assess the effectiveness of our approach. Thus, we present a set of activities based on Hasan’s (1985/1989,2007) framework for the analysis of verbal art as a ‘special’ register, which is rooted in FG. We then discuss quantitative and qualitative data related to student perceptions of our pedagogical approach, gathered through specifically designed questionnaires, which were followed by semi-structured interviews when possible. The data illustrate the largely positive impact of the approach on students’ engagement, though not unequivocally: problematic issues and implications for future research are also discussed.
Elaboration, compression and explicitness across sub-registers of popular and academic writing in Hong Kong English
Authors: Seoane Elena , Suárez-Gómez Cristina 
Published: July 2020

AbstractIn this study we examine elaboration, compression and explicitness in academic and popular writing in an Outer Circle variety of English, that of Hong-Kong, as represented in the International Corpus of English corpus. AsBiber and Gray (2016)show, contemporary academic discourse is structurally compressed at NP level (rather than elaborated) and inexplicit in the expression of meaning. The linguistic features selected for analysis are short passives, which are compressed and inexplicit, and adnominal relative clauses, which represent the opposite tendency, that towards elaboration and explicitness. We focus on register variation through analyzing, first, differences between academic and popular writing, and second, interdisciplinary variation in four sub-registers: humanities, social sciences, natural sciences and technology.
Tourism development in Mexico.
Authors: Osorio-García Maribel , Novo Gerardo 
Published: July 2020

Abstract

This chapter analyses tourism development and impacts in Mexico from a sociological perspective. By arguing that tourism development in the country is structurally articulated by the condition of being a developing country, the chapter critically reviews the evolution of tourism development through four major tourism strategies implemented by the Mexican federal government: State Planned Destinations, 'Magic Towns' programme, Ecotourism Projects and Heritage Cities. In so doing, this chapter reveals tourism's economic contribution to the national income, but also documents some of its major socio-economic and cultural drawbacks for local populations. It is concluded that tourism models in Mexico have provided very uneven benefits for their economic agents, though it is relevant that some produce low-quality employment and insufficient income, which stresses poverty and contravenes inclusive development. Practical recommendations are presented to reduce tourism's negative impacts in the country.
The impacts of tourism in economic growth and development in Uruguay.
Authors: Brida Juan Gabriel , Lanzilotta Bibiana , Pizzolon Fiorella , Rodríguez Brindis Martín 
Published: July 2020

Abstract

This chapter takes an economic perspective to study the contribution of tourism to economic growth and development in Uruguay. Reporting that Uruguay is the Latin American country that receives the highest proportion of tourists in terms of its population, the chapter quantifies the contribution of tourism to economic growth in the past three decades and analyses whether international tourism can be strategically used as a factor for long-run economic growth and development for the country. By describing the different periods through which tourism development in Uruguay has gone, it is revealed that the increase in the contribution of the Uruguayan tourism sector in recent years has been associated and concomitant with the implementation of a set of public policies and programmes.
Research on the monitoring early warning system for the foundation pit construction passing through the original subway elevated pile foundation on the basis of information exchange
Authors: Su Huifeng , Li Renzhuang , Lv Yujie 
Published: July 2020

Abstract
The research background is the foundation pit excavation of the new metro station which passes through the existing metro elevated pile foundation. By using the finite element analysis method, the numerical simulation of the excavation of the foundation pit is carried out. The supporting structure in the excavation of the foundation pit and the safety of the original subway Viaduct Pile close to the foundation pit are studied. Through the research, the calculation results of the force and displacement deformation of the supporting structure and the original Metro Viaduct Pile in the process of foundation pit excavation are obtained. After comparing the above calculation results with the monitoring values, the reasonable optimization scheme for the support structure is obtained. In addition, through the method of building database, the information of structure attribute between the finite element model and BIM model is exchanged. On this basis, the visual programming method dynamo is introduced, the command flow and some custom nodes are compiled, and the mutual flow of monitoring information and early warning information between the finite element model and BIM model is completed. This realizes the safety control method of subway construction based on BIM Technology, which integrates engineering information, monitoring and early warning.
The Influence of Pressurization Device under PASCAL Principle on the Efficiency of Setting Load of Hydraulic Support
Authors: Liu Qihang 
Published: July 2020

Abstract
In order to avoid safety accidents caused by poor protection of hydraulic support in coal mine operation, in this research, a supercharging device based on PASCAL principle is designed. First of all, the cause of insufficient setting load of hydraulic support is analysed. Then, the hydraulic system circuit and the supercharging device structure are designed. Finally, the effect of the supercharging device based on PASCAL principle designed in this research on the setting load of the hydraulic support is simulated and verified by field tests. The results show that the supercharging device based on PASCAL principle proposed in this research has a very obvious enhancement effect on the setting load of the hydraulic support. The results of field experiments further verify that the supercharging device designed in this research can increase the setting load of the hydraulic support. This research provides a good idea for improving the protection performance of hydraulic support.
Automatic Interpretation for Telemetry Parameters Based on prediction method
Authors: Dong Suhui , Cui Changwen , He Pengju , He Changan , Kang Weiwei 
Published: July 2020

Abstract
Based on prediction method, a novel method of automatic interpretation for problem of the slow-varying telemetry parameters changing suddenly is proposed. Firstly, extract the envelope of the flight data and then filter the envelop. Secondly forecast the filtered envelop using linear prediction method and prediction method based on GM (1,1) model. Finally, according to the estimated value and standard deviation of the parameters, the statistical analysis of the target data is carried out, where the parameters are determined to be abnormal or not according to the analysis result, so as to realize the automatic interpretation function of the parameters. The test results show that the prediction method based on GM (1,1) model can effectively identify the mutation or pulsed parameters in the slow-varying telemetry parameters Compared with the traditional method of the artificial interpretation, this method can effectively improve the efficiency and accuracy of the telemetry parameter interpretation.
Research on Coal and Rock Image Recognition Based on 2DPCA Algorithm
Authors: Xu Yao 
Published: July 2020

Abstract
The PCA algorithm in coal and rock recognition had some fundamental flaws such as large computation and low efficiency. In this paper, a coal and rock image recognition method based on 2DPCA algorithm was proposed. The experimental results showed that this method could not only reduce the dimension of the original feature, but also reduce the complicated calculation and improve the recognition accuracy effectively.
Development status and application prospect of semi-active vibration reduction technology for down-hole drilling tools
Authors: Zhao Jianjun 
Published: July 2020

Abstract
Domestic and foreign oil companies have been constantly increasing the research and development investment in underground shock absorber, to reduce the vibration and shock of drilling tool under hard rock drilling environments, enhance the rate of penetration and decrease drilling cost under the premise of ensuring the normal life of drill string components and stable bit weight. Based on this, this paper has focused on the working principal of magneto-rheological fluid (MRF) semi-active damper, the composition of MRF and its internal parameters’ impact on the damping characteristics, combining with the status quo at home and abroad of down-hole vibration technology. Meanwhile, the test analysis of semi-active damping technology was conducted. And the results showed that semi-active vibration technology had greatly weakened the vibration level while improved the rate of penetration, guaranteed the service life of bit and other drill-string components, reduced additional tripping times and effectively solved the problems of bit weight instability and low penetration rate etc., caused by drill vibration. Therefore, in the current situation of worldwide oil price downturn, it has become increasingly prominent to reduce cost and increase efficiency, and it’s particularly necessary to research on the shock absorbers of down-hole drilling tools in China.
Experimental study on the peeling characteristics of wax on the surface of plastic alloy pipe and glass steel pipe
Authors: Liu Wei , Ding Haopeng , Wu Yan , Miao Kun , Deng Zhian , Wen Ziyan 
Published: July 2020

Abstract
Plastic alloy pipes and glass steel pipes are two widely used non-metallic pipes. In this paper, sliced paraffin was used to perform waxing and peeling experiments on the lining surfaces of two types of pipes, investigating the effects of temperature and wax thickness on the surface peeling force of two types of pipe line. This experimental study has certain guiding effect on the selection of non-metallic pipes and the design of the wax removal device.
Influence of FSI on the Natural Frequencies and Mode Shapes of Tubing
Authors: Liu Hongtao , Zhang Wei , Cao Yinping , Dou Yihua 
Published: July 2020

Abstract
Numerical simulation method was adopted to analyze the influence of fluid-solid interaction (FSI) on the vibration characteristics of tubing. The natural frequencies and mode shapes of tubing were analyzed for the cases of no FSI, gas-solid interaction, and liquid-solid interaction in the modal module of ANSYS Workbench software. It shows that natural frequencies of tubing decreased when considering FSI. The decrease is greatest for the case of liquid-solid interaction, which is more than 13% compared with gas-solid interaction. The mode shapes are almost unchanged even considering FSI. The results show that the effect of FSI can not be ignored, especially when the internal fluid density is large.
The study of elastic properties of fractured porous rock based on digital rock
Authors: Zhao Jianpeng , Chen Hui , Li Ning 
Published: July 2020

Abstract
Knowledge of the elastic properties of fractured rock plays a significant role in accurate and rigorous reservoir description. In this paper, we carry out a systematic study about the effect of fracture width, fluid properties on elastic properties of reservoir rocks based on digital rock technology. Digital rock models with different fracture width are reconstructed via a superposition reconstruction procedure which impose a fracture on an isotropic host rock. A modified Finite Element Method (FEM) is adopted to investigate rock elastic properties. The results show that the presence of fracture leads to a strong anisotropy of rock. The five elastic constants of the resultant TI medium are derived as a function of the properties of the fracture width and fluid bulk modulus. The aspect ratio of P-wave velocity and S-wave velocity (V
p/V
s) is a function of fluid bulk modulus and can be used to identify fractured gas reservoir. The results allow one to have a better understanding about the correlations of fracture, fluid and elastic properties of reservoir rocks.
A system-level analysis model for lunar calibration of multispectral payload on remote sensing satellites
Authors: Xu Chi , He Tao , Huang Jin , Ren Fang 
Published: July 2020

Abstract
Remote sensing satellites are playing an increasingly important role in earth resource exploration, and the radiometric calibration on orbit of satellite has an important impact for retrieving information of earth resources from remote sensing images of a satellite. This paper presents an system-level analysis model for lunar calibration suitable for multispectral payload of remote sensing satellites. Through simulation and calculation analysis, the results show that this method can obtain the payload imaging parameters which are required for lunar calibration missions, ensure the quality of remote sensing images and the accuracy of radiation calibration, and provide reliable data for retrieving information of earth resources.
Research on the Phenomenon of Shear Force Over Limit in the Upper Shear Wall of Frame Supported Beam
Authors: He Ye , Zhang Kui 
Published: July 2020

Abstract
With the development of high-rise buildings, part of the frame structure is usually used to support the upper reinforced concrete shear wall, in order to form a large space. Thus a framed shear wall structure is formed. The shear force design value of the shear wall which is on top of the frame supported beam often exceeds limit value that a shear wall can bear during the construction design process. This does not meet the requirements of the current national code. A high-rise building with transfer story in 7 degree earthquake area is taken as an example to analyze the reason of shear wall over limit by using structural design software PKPM in this paper. Through numerical simulation analysis, it is concluded that the main reason for the shear force over limit is that the increase of constant load, which results in the increase of relative deformation of the frame supported beam and the shear wall, as well as the axial force of the coupling beam. Specific measures to reduce the shear force over limit are proposed by using a finite element analysis software MIDAS, which provides references for a structural engineer to carry out the design.
The overall seimic performance analysis of the web light-gauge steel joist structure
Authors: Qin Liyun 
Published: July 2020

Abstract
The WEB Light-Gauge Steel has the advantages of superior seismic performance, low cost, efficient construction speed and so on, and can better deal with the emergency under the rapid construction and put into use. In this paper, ABAQUS finite element program is used to analyse the time history of two-story buildings with extremely light steel structure. The displacement time history curve, acceleration time history curve is successively compared with the opening and depth as the reference variables. It is concluded that the depth of the room has a significant effect on the overall seismic stiffness of the structure, and the selection of the length-width ratio of the plane form of the structure should be considered in the seismic analysis.
Analysis and Research on Microseismic Signal Characteristics and Energy Change of Working Face in Liyazhuang Mine
Authors: Lu Zhanjin 
Published: July 2020

Abstract
To provide a certain support for the prediction of the rockburst and setting of the threshold, the SOS microseismic monitoring system is used to remotely, real-time, dynamic and automatic monitoring of the seismic signal of the 2-228 working face of Liyazhuang coal mine. And the original signal of the microseismic is processed by the window Fourier transform, and the characteristics of the microseismic waveform and spectrum of different energy levels are analyzed. The results show that there are different characteristics of waveform and spectrum corresponding to signals at different energy levels. The high amplitude, low and centralized main frequency, long duration of signal, coda waves developing obviously than head wave and slow attenuation are the typical characteristics of strong mine earthquake. With the decrease of mine earthquake energy, the vibration attenuation rate gradually becomes faster, and the duration of the signal being shorter, the development of the head wave being obvious, the amplitude of velocity decreasing correspondingly, but the rate of amplitude decreasing gradually slows down, and the main frequency is gradually spread from concentration to diffusion, while the frequency distribution range is affected rarely. The research results can provide a scientific basis for setting the threshold of shock pressure prediction index and its risk prediction.
Design and field test of drilling composite impactor
Authors: Zhao Jianjun , Cui Xiaojie , Cao Haitao , Yin Huibo 
Published: July 2020

Abstract
When the PDC drill bit encounters the heterogeneous and highly abrasive formation, it comes up with problems such as serious stick-slip phenomenon, shallow depth of penetration and short service life, and meanwhile, the rapid drilling tool with a single impact function cannot meet the drilling acceleration demand of exploration and development in deeper and more complex formation. Therefore, as a complementary implement of the traditional percussion drilling tools, a efficient drilling composite impactor has been designed, which is capable of applying both the reciprocating torsional impact and the reciprocating axial impact. The impact characteristic parameters of the tool have been obtained through the ground performance test, which also verifying the reliability of the composite impact timing, in addition, the field application has been carried out in Tian17-Xie12 well. And the results show that the key drilling parameters, such as well inclination and azimuth, change stably, thus shortening the sliding drilling time, and compared with adjacent wells, the tool above-mentioned has improved the mechanical drilling rate by 38%.
Simulation and Filed Test on Dynamic Formation Mechanism of the Rotary Percussion Drilling Tool
Authors: Ma Mingxin , Tian Zongzheng 
Published: July 2020

Abstract
Rotary percussion drilling tool can effectively improve the drilling speed in the hard formation. However, due to the impact of drilling fluid, the erosion of the dynamic and static valve disc is serious, which can reduce the impact effect. In this paper, the flow field characteristics and erosion characteristics of the dynamic forming mechanism are analyzed by numerical simulation and test, while the dynamic and static valve disc of dynamic formation mechanism is improved, which is verified by field test. The results show that the pressure from the entrance to the surrounding walls is higher and higher. The maximum velocity of drilling fluid is distributed near the edge of the outlet. The study will provides theoretical and technical guidance for increasing tool life and rate of penetration in hard formations.
Research on Working Viscosity and Influencing Factors of Polymer Solution in Seepage Process
Authors: Li Dan , Fei Chunguang , Wang Lihui , Xia Huifen 
Published: July 2020

Abstract
Using seepage experiments and theoretical methods, the pseudo-residual resistance factor is introduced, the working viscosity calculation method is modified, and the influence of the viscosity and injection speed of the polymer solution on the change of working viscosity in porous media with different permeability is studied. The pseudo-residual resistance factor calculation is more reasonable to describe the dynamic change of working viscosity during the displacement process; as the permeability and viscosity of the injection fluid increase, the working viscosity of the polymer in the porous medium increases; as the injection speed increases, the polymer shows Viscoelasticity, working viscosity shows a trend of decreasing first and then increasing.
Main controlling factors and remaining oil distribution in ancient buried hill reservoir
Authors: Liu Yang 
Published: July 2020

Abstract
The paleo buried hill in the study area belongs to the metamorphic rock buried hill reservoir, and the reservoir conditions are controlled by the dual factors of structure and dissolution; the comprehensive structural relative difference, the network fracture network characteristics of the reservoir space and the development scale of the secondary dissolution holes are divided into three types of buried hill reservoir; through the comprehensive study of the reservoir characteristics and the reservoir forming conditions of the buried hill reservoir, the source rock fault transport and the fracture and cave development of the buried hill reservoir The main controlling factors for the formation of buried hill reservoir in the study area are the degree of development and sealing conditions. Based on the comparative analysis of a large number of field data such as drilling, oil testing, logging, logging interpretation, oil-water identification and production performance, the trap characteristics, original oil-water interface, rising speed of oil-water interface and water flooded surface condition of buried hill reservoir are clarified, thus guiding the distribution of remaining oil.