Abstract.Hydraulic fracturing is one of the most effective methods to improve the permeability of coal seams at present. In order to promote the development of hydraulic fracturing technology in coal mines, the current development of hydraulic fracturing technology in coal mines is summarized from three aspects of hydraulic fracturing influencing factors, hydraulic fracturing methods and processes, and hydraulic fracturing effect evaluation. It is believed that the mechanism of hydraulic fracturing influencing factors, intelligent fracturing equipment, and systematic fracturing effect evaluation … Read more →

Abstract.The Riserless Well Intervention (RLWI) system that performs complex offshore oil well Plugging and Abandonment (P&A) operations is a typical Multi-Mission Phased-Mission System (MM-PMS), which requires multiple missions to be completed within a phase. P&A processes involve complex operations and equipment that can contaminate local marine ecosystems if they fail. Therefore, it is necessary to evaluate the reliability of the RLWI system. This paper proposes a dynamic reliability evaluation model for analyzing the RLWI MM-PMS. The GO model of the phase operation process and the Fault Tree (FT) … Read more →

Abstract.Based on the DEM-CFD method, the solid-liquid two-phase flow in an axial flow pump was simulated, and the velocity and trajectory of particles passing through the impeller and deflector were investigated. It was found that the particles accelerated about 150% after passing through the impeller. Five solid concentration schemes were set up to explore the influence of solid concentration on particle velocity and average residence time. The maximum velocity of particles at different concentrations tended to 10 m/s; The average residence time of particles in low concentration scheme (2%) is 120% … Read more →

Abstract.Since the planning of China's urban logistics system does not include end-of-line distribution in the unified planning, and less consideration is given to the cooperative distribution of multiple subjects, resulting in the overall low efficiency of the transportation link; at the same time, considering the impact of the epidemic on logistics distribution, "electric unmanned vehicles" with high efficiency, low cost and no contact characteristics become an important tool for end-of-line distribution. In summary, this paper takes the urban end distribution scenario as the research object, builds … Read more →

Abstract.In order to solve the separation efficiency problem of the vertical centrifuge. First, understand the working principle and dynamic theory of the centrifuge, preliminarily design the technical parameters from the experience and experimental data of the prototype, solid works model, specify the overall structure scheme, and complete the virtual assembly. Secondly, the work performance is verified. The production capacity is calculated with power to meet the design requirements. Then, to verify the design strength and deformation meet the design requirements. Then, the finite element numerical … Read more →

Abstract.Critical thinking is an important symbol of intelligent talents, which is conducive to cognitive ability. It is also called the cornerstone and promoter of rational society. Basic education should be to cultivate critical thinking ability as the primary goal. Through the exploration of English reading teaching in high schools, this research explores how to strengthen students’ critical thinking in reading. That is, to propose effective practice strategies from the teacher level, curriculum level, etc. Read more →

Abstract.The research on the optimization of T-beam under the condition that both T-beam and rectangular section beam meet the section bearing capacity. Through theoretical calculation, component fabrication, experiment, and data collection and analysis, fully explore the advantages of a T-beam, optimize the experimental beam transport process, and apply it to practical teaching to improve the safety and convenience of the experimental process. Read more →

Abstract.Geothermal energy is a kind of renewable energy with rich content, relatively low cost and wide distribution. China is rich in geothermal reserves and urgently needs efficient heat extraction technology. Closed cycle heat extraction technology is a new geothermal development model that is suitable for medium-deep geothermal reservoir and has high heat exchange efficiency without taking water. In this system, the circulating working fluid is pumped into the annulus from the ground, and the heat is extracted from the formation through heat conduction, and then returned to the ground through the … Read more →

Abstract.The riser is the only channel connecting the submarine pipeline oil gas and offshore platform structures, offshore oil and gas development and utilization of lifelines, offshore pipeline system is the weakest vulnerable link. Due to its long and thin structure, the marine riser is easy to failure and failure in the complex working conditions. Marine vibration pipe safety or not directly affects the marine engineering and the surrounding environment and marine biology, in the event of damage, can cause the economic loss and environmental pollution, will result in a casualties, and even cause … Read more →

Abstract.Glass is a valuable material evidence of our early trade exchanges, and our glass is mainly divided into high potassium glass and lead-barium glass. The specific types can be distinguished by examining the content of their internal compounds. This paper delineates the broad types of each unknown artefact and then predicts the composition before weathering. Combining the results of existing predicted subclasses as known data, 80% of the data is selected as the training set and 20% as the test set. Suitable node splitting evaluation criteria and feature division point selection criteria were … Read more →

Abstract.This paper classifies 19 human actions based on a dataset of 1.2 million human actions acquired from sensors. The Xgboost classification model is established, and the MIV algorithm is used as an index to evaluate the importance of each variable to the dependent variable. The MIV values of all features are sorted according to the absolute value of each variable, and finally the top 10 groups of features are selected as the features of the reduced data set, and fine-tuned by grid search. Select the simplified data set, get the maximum roc_auc through continuous testing, and get the optimal … Read more →

Abstract.With the rapid development of modern industry and agriculture, metal ion wastewater is being discharged unchecked, resulting in serious pollution of water and soil resources systems. At the same time, the unrestrained exploitation and waste in recent decades have led to the gradual depletion of metal ion mineral resources. Among them, rare earth metal ions, as national strategic resources, have application value in many high-tech fields. Therefore, how to effectively separate and recycle metal ions in wastewater is one of the research hotspots. Adsorption separation technology has the … Read more →

Abstract.Based on the important role of reclamation and ecological restoration of industrial and mining wasteland in improving the ecological environment quality, expanding the land use space and improving and ensuring people's livelihood in China, this paper analyzes the current situation of reclamation of industrial and mining wasteland in China according to the current standards of reclamation and ecological restoration of industrial and mining wasteland in China, and summarizes the problems in the current reclamation and ecological restoration of industrial and mining wasteland in China, The … Read more →

Abstract.With the development of economy and social progress, the development of China's industrial sector is booming, and the construction of oil and gas pipelines is speeding up. The inspection and maintenance of pipelines has become the current research focus. Through the analysis of the working environment and characteristics of the existing six categories of pipeline robots, the current research status of pipeline robots is systematically expounded, and the current research difficulties of pipeline robots are summarized. The summary and analysis contents have certain reference value for the future … Read more →

Abstract.The farmland soil is combined pollution by multi-heavy metals in China, which seriously threatens the food security and the human health. This paper makes a review of the characteristics of the heavy metal contaminated farmland soil and the types and characteristics of common remedial materials. In addition, this paper analyzed and forecasted the problems that need to be solved in the future for remedial materials for heavy metal contaminated soil. Common remediation materials include biochar, clay minerals, organic matter, phosphates, metal oxides and composite remediation materials, etc. The … Read more →

Abstract.Affected by factors such as repeated delays in the epidemic, climate change and frequent natural disasters, food security risks are prominent, and it is imperative to ensure food security. The construction of high-standard farmland is a realistic need to improve comprehensive agricultural production capacity and ensure food security, but in the construction process, there is a phenomenon of attaching importance to construction and neglecting management and protection, resulting in the failure of the completed high-standard farmland to play a sustained and efficient role, resulting in damage to … Read more →

Abstract.ZTA ceramic materials are widely used in the field of orthodontics, however, the existing material preparation and its properties do not meet the requirements of orthodontic instruments. In this paper, SiC whiskers with high purity, high aspect ratio and stable properties were prepared by adding high hydrogen-containing silicone oil to ZTA ceramics to improve their fracture toughness and densities, and the ceramic matrix was prepared by gelation, curing and sintering with cellulose acrylic acid graft co-polymer as binder. In particular, the synergistic toughening effect with zirconia in the … Read more →

Abstract.The purpose of this study is to study the state of gas-solid two-phase transportation process in different types of pipelines, so as to find out the cause of pipeline blockage. The horizontal pipe is the most common arrangement in the pneumatic conveying pipeline, and the gravity direction of particles in the horizontal pipe pneumatic conveying is perpendicular to the flow direction, which makes the flow of oil well cement particles in the horizontal pipe more complex, so it is very necessary to study the pneumatic conveying process of the horizontal pipe. Read more →

Abstract.Lack of understanding of the text structure is the major problem in English reading teaching in junior high school and senior high school at present. High school English teaching is not only for the college entrance examination, but also to cultivate students' ability of listening, speaking, reading and writing. Because traditional teaching focuses on the interpretation and grammar of words. Teachers help students understand the text by explaining the text word for word, combing the language points and grammatical phenomena of the text, and practicing the words and phrases repeatedly, … Read more →

Abstract.This paper from the management science, economics, organization behavior science, philosophy, science of culture, psychology, sociology and systems theory and other aspects of the relevant theory of enterprise culture and its construction theory support. From the principle and characteristics of the corporate culture, the structure and function of enterprise culture, operation platform, enterprise culture evolution mechanism, operation path and so constructed theory analysis framework of enterprise culture. Based on the evaluation of elements from the spirit of enterprise culture, enterprise … Read more →

Abstract.In order to explore the crushing effect of roof teeth on granite in Qinghai Oilfield, the rock breaking efficiency of roof teeth was studied. Through the indoor single tooth rock breaking experiment, rock mechanics parameter experiment and numerical simulation of the rock breaking process of roof teeth, the influence of cutting parameters (depth and rake angle) of roof teeth and tooth arrangement mode on the rock breaking efficiency of roof teeth is judged. Through analysis, the best cutting parameters of plane teeth are 5 °, 3mm; The best cutting parameter of ridge teeth is 5 °, 2mm deep, and … Read more →