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To build a digital twin model of intelligent longwall coal mining, this paper presents a new full-parameter position and attitude digital twin model of hydraulic supports. A full-parameter matrix describing the position and attitude of a support is established first. Then, the position and attitude digital twin model of a support based on this matrix is built. Afterward, a position and attitude digital twin model of the hydraulic support system in the workface is established using the Unity3D software and the Runge–Kutta algorithm as a motion calculation method. Finally, a simulation experiment is conducted based on the digital twin model of hydraulic supports, and results show its effectiveness. This digital twin model has the potential to control the hydraulic support system in future intelligent coal mining.

In Czechia, harvesters contributed 43% of the total annual timber production in 2022. It is assumed that harvester technology will continue to be used intensively in the future, even though there is a change in the tree species composition of forests after the recent bark beetle outbreak and an increase in the use of close-to-nature forest management. The aim of this study was to analyse the over- and under-bark volume estimates of European larch timber produced by a harvester in Czechia. This study used the M3s price category for volume estimation. This volume was compared with the M3toDE price category. The M3toDE price category underestimated the over-bark volume by 5.59% compared to the M3s price category. However, for use in forestry practice in Czechia it is currently necessary to use the M3toDE price category. Therefore, the M3toDE price category was used to compare under-bark volumes according to different bark deduction methods. Differences were found between all the five methods investigated. Understanding this sub-issue will help in training operators, acquiring comprehensive knowledge about the functioning of harvester software and maximising the economic effect of the sale of larch timber.

The transfer matrix method for multibody systems has been developed for 20 years and improved constantly. The new version of transfer matrix method for multibody system and the automatic deduction method of overall transfer equation presented in recent years make it more convenient of the method for engineering application. In this article, by first defining branch subsystem, any complex multibody system may be regarded as the assembling of branch subsystems and simple chain subsystems. If there are closed loops in the system, the loops should be “cut off,” thus a pair of “new boundaries” are generated at each “cutting-off” point. The relationship between the state vectors of the pair of “new boundaries” may be described by a supplement equation. Based on above work, the automatic deduction method of overall transfer equation for tree systems as well as closed-loop-and-branch-mixed systems is formed. The results of numerical examples obtained by the automatic deduction method and ADAMS software for tree system dynamics as well as mixed system dynamics have good agreements, which validate the features of proposed method such as high computational speed, more effective for complex systems, no need of the system global dynamics equation, highly programmable, as well as convenient popularization and application in engineering.

In geotechnical engineering, the support pattern regularly applied is continuous wall, whose high security, strong adaptability, good stability and other characteristics have been widely appraised in engineering circles. This paper use Midas to build the three-dimensional research model on varied construction stages of foundation pit, in which the foundation pit applies the scheme of combing continous wall and inner support. Further more, this paper makes estimation on the machenical stability in varied construction stages of foundation pit and use strength deduction method to analyze the stress and strain conditions of foundation pit in different working states, the results acquired from which researches have certain reference to the engineers.

At first sight, detective fiction and geography appear as two opposing fields of study. Geography relies on tangible scientific information while detective novels create mysteries around whodunnits, notably with Doyle’s Sherlock Holmes adventures. Detective Holmes reasons backwards, relying on his ‘theory of deduction’, a fictional method of using pertinent facts to unravel murder mysteries usually committed in dubious circumstances. Holmes’s method, however, stems from concrete geographical details. The purpose of looking at both ‘sciences’ in Doyle’s A Study in Scarlet is to facilitate the study of facts and fiction, from which emerges a juxtaposition in which character depiction and narration are dialectically intertwined. Reading together the art of fiction and the science of geography thus becomes a critical necessity. Looking at both indeed enables us to grasp more fully how character depiction and narrative structure operate in Doyle’s detective stories.

تحتل القرائن القضائية في العصر الحاضر مرتبة متميزة بين سائر وسائل الإثبات الجزائي، إذ أنها لا تدل على الأمر المستهدف من الإثبات فحسب، وإنما تصلح أن تكون دليلاً قائماً بذاته يغني عن سواها من الأدلة الأخرى، ذلك أن الإثبات في المجال الجزائي يتعلق بوقائع مادية يتعذر إعداد الدليل بشأنها مسبقاً، وقلما يتوفر الدليل المباشر عليها، خاصة حين يعمد مرتكبو الجرائم إلى طمس معالمها تضليلاً للعدالة، فلا يجد القاضي أمامه سوى الوقائع المرتبطة بالجريمة فيحاول استنطاقها، والاستدلال بها على ما قد يكون لازماً أو مرتبطاً بها، مما قد يغفل عنه الجاني أو يهمله جهلاً بتأثيره في الكشف عنه. وفضلاً عن ذلك فإن التقدم العلمي الهائل الذي عم مختلف المجالات قد زاد من أهمية القرائن بالنسبة للوقائع المادية، ذلك أن المجرمين قد استفادوا بشكل كبير من التطورات العلمية، مما صعب مهمة القضاة في الكشف عنهم بالاعتماد على وسائل الإثبات التقليدية، ومن هنا أصبح من الضروري الاستعانة بوسائل الإثبات الحديثة التي وفرها العلم الحديث، ولن يكون ذلك إلا عن طريق الاستعانة بالقرائن في الإثبات.

When producing an argumentative text, the writer adopts a definite position and advances arguments in support of it. The textual arrangement of these two cardinal components of argumentation varies across cultures, causing difficulties in learning to write persuasively in foreign languages. The present paper investigates the text organization of a sample of English argumentative essays written by a group of Arabic-speaking learners of English as a foreign language (EFL). The analysis aims at delineating the factors leading them to project texts non-conforming to English argumentative discourse conventions. The findings reveal that multiple factors underlie learners' textual preferences.