Experimental investigation on coal pore-fracture variation and fractal characteristics synergistically affected by solvents for improving clean gas extraction

Chemical solvents instead of pure water being as hydraulic fracturing fluid could effectively increase permeability and improve clean methane extraction efficiency.However,pore-fracture variation features of lean coal synergistically affected by solvents have not been fully understood.Ultrasonic testing,nuclear magnetic resonance analysis,liquid phase mass spectrometry was adopted to comprehensively analyze pore-fracture change characteristics of lean coal treated by combined solvent(NMP and CS_(2)).Meanwhile,quantitative characterization of above changing properties was conducted using geometric fractal theory.Relationship model between permeability,fractal dimension and porosity were established.Results indicate that the end face fractures of coal are well developed after CS2and combined solvent treatments,of which,end face box-counting fractal dimensions range from 1.1227 to 1.4767.Maximum decreases in ultrasonic longitudinal wave velocity of coal affected by NMP,CS_(2)and combined solvent are 2.700%,20.521%,22.454%,respectively.Solvent treatments could lead to increasing amount of both mesopores and macropores.Decrease ratio of fractal dimension Dsis 0.259%–2.159%,while permeability increases ratio of NMR ranges from 0.1904 to 6.4486.Meanwhile,combined solvent could dissolve coal polar and non-polar small molecules and expand flow space.Results could provide reference for solvent selection and parameter optimization of permeability-enhancement technology.

Dance2MIDI:Dance-driven multi-instrument music generation

Dance-driven music generation aims to generate musical pieces conditioned on dance videos.Previous works focus on monophonic or raw audio generation,while the multi-instrument scenario is under-explored.The challenges associated with dancedriven multi-instrument music(MIDI)generation are twofold:(i)lack of a publicly available multi-instrument MIDI and video paired dataset and(ii)the weak correlation between music and video.To tackle these challenges,we have built the first multi-instrument MIDI and dance paired dataset(D2MIDI).Based on this dataset,we introduce a multi-instrument MIDI generation framework(Dance2MIDI)conditioned on dance video.Firstly,to capture the relationship between dance and music,we employ a graph convolutional network to encode the dance motion.This allows us to extract features related to dance movement and dance style.Secondly,to generate a harmonious rhythm,we utilize a transformer model to decode the drum track sequence,leveraging a cross-attention mechanism.Thirdly,we model the task of generating the remaining tracks based on the drum track as a sequence understanding and completion task.A BERTlike model is employed to comprehend the context of the entire music piece through self-supervised learning.We evaluate the music generated by our framework trained on the D2MIDI dataset and demonstrate that our method achieves state-of-the-art performance.

基于数据分析应用平台的中小企业商业信用政策动态调整案例研究

数字化转型背景下,数据要素成为企业重要资产。长期以来,商业信用政策一直是中小企业生存与发展过程中的痛点和难点,会计数字化转型的出现为中小企业商业信用政策动态调整提供了有力支撑。本文从梳理数字化转型与商业信用政策的相关文献出发,重点分析与评价S公司数据分析应用平台如何支撑其商业信用政策的动态调整,并给出进一步优化的建议。