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Molecular Dynamics-Based Simulation of Polyethylene Pipe Degradation in High Temperature and High Pressure Conditions

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Fluid Dynamics & Materials Processing 2024年第9期20卷 2139-2161页

作者： Guowei Feng Qing Li Yang Wang Nan Lin Sixi Zha Hang Dong Ping Chen Minjun Zheng School of mechanical Engineering Xinjiang UniversityUrumqi830046China xinjiang Yian Special Inspection Engineering Company Limited Urumqi830063China xinjiang Uygur Autonomous Region Inspection institute of Special equipment Urumqi830000China Pressure Pipe Department China Special Equipment Inspection and Research InstituteBeijing100013China Tarim Oilfield Branch Company Korla841000China Yimai Cai Oil and Gas Management Area Tarim Oilfield Branch OfficeKorla841000China

High-density polyethylene(HDPE)pipes have gradually become the first choice for gas networks because of their excellent *** the use of pipes increases,there will unavoidably be a significant amount of waste generated when the pipes cease their operation life,which,if improperly handled,might result in major environmental contamination *** this study,the thermal degradation of polyethylene materials is simulated for different pressures(10,50,100,and 150 MPa)and temperatures(2300,2500,2700,and 2900 K)in the framework of Reactive Force Field(ReaxFF)molecular dynamics *** main gas products,density,energy,and the mean square displacement with temperature and pressure are also *** findings indicate that raising the temperature leads to an increase in the production of gas products,while changing the pressure has an impact on the direction in which the products are generated;the faster the temperature drops,the less dense the air;both temperature and pressure increase impact the system’s energy conversion or distribution mechanism,changing the system’s potential energy as well as its total energy;the rate at which molecules diffuse increases with temperature,and decreases with *** results of this investigation provide a theoretical basis for the development of the pyrolytic treatment of polyethylene waste materials.

关键词： ReaxFF MD high-density polyethylene degradation temperature pressure

Impact of agricultural residual plastic film on the growth and yield of drip-irrigated cotton in arid region of xinjiang, China

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International Journal of agricultural and Biological Engineering 2020年第1期13卷 160-169页

作者： Can Hu Xufeng Wang Shiguo Wang Bing Lu Wensong Guo Chaoji Liu Xiuying Tang College of Engineering China Agricultural UniversityBeijing 100083China College of mechanical and Electrical Engineering Tarim UniversityAlar 843300XinjiangChina xinjiang academy of agricultural and reclamation science mechanical equipment research institute Shihezi 832000China

Long-term and widespread use of plastic mulching has led to the accumulation of residual plastic film(RPF)in farmland soils of xinjiang,***,there is no specific quantitative basis for RPF pollution or a clear understanding of the influence of residual film on crop *** aim of this study was to investigate the effect of RPF on the growth of cotton,an important cash crop of *** on the field conditions and previous reports,various amount of residual film was applied in 0-30 cm soil *** growth index including emergence rate,dry matter,and yield of cotton was examined at different growth stages under different soil residual film *** demonstrated a significant effect of RPF on soil moisture distribution and *** residues had a significant effect on cotton growth at levels above 200 kg/hm2,and the yield decreased as the RPF amount *** on these findings,200 kg/hm2 was suggested as a threshold level to determine the effects of RPF on *** study provided a basis to rate RPF pollution in farmland soils and help understand the impact of pollution on crop productivity.

关键词： residual plastic film plastic film pollution soil pollution pollution control cotton production management

Stability mechanism and control of the pumpable supports in longwall recovery room

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International Journal of Mining science and Technology 2024年第07期 957-974页

作者： Dong Zhang Jianbiao Bai Zhijun Tian Zizheng Zhang Yonghong Guo Rui Wang Ying Xu Hao Fu Shuai Yan Min Deng Shuaigang Liu State Key Laboratory of Coal Resources and Safe Mining China University of Mining and Technology Key Laboratory of xinjiang Coal Resources Green Mining Xinjiang Key Laboratory of Coal-bearing Resources Exploration and ExploitationXinjiang Engineering Research Center of Green Intelligent Coal MiningXinjiang Institute of Engineering Work Safety Key Laboratory on Prevention and Control of Gas and Roof Disasters for Southern Goal Mines Hunan Provincial Key Laboratory of Safe Mining Techniques of Coal MinesHunan University of Science and Technology School of Mines China University of Mining and Technology

The load-bearing performance （LBP） of pumpable supports （PPS） is crucial for the stability of longwall pre-driven recovery room （PRR） surrounding ***,the unbalanced bearing coefficient （UBC）of the PPS （undertaking unequal load along the mining direction） has not been investigated.A mechanical model of the PRR was established,considering the main roof cantilever beam structure,to derive an assessment formula for the load,the failure criteria,and the UBC of the ***,the generation mechanisms,and influencing factors of the UBC were *** sensitivity analysis shows that the main roof hanging length （l2） and the spacing between the PPS （r） significantly impact the UBC.A novel design of the PPS and the coupling control technology were proposed and applied to reduce the UBC of the PPS in the adjacent longwall *** results showed no failure of the PPS at the test site,with the UBC （ζ） reduced to 1.1 consistent with the design value （1.15） basically,fully utilizing the collaborative LBP of the ***,the maximum roof-to-floor convergence of the PRR was 234 mm,effectively controlling the stability of the surrounding rock of the PRR and ensuring the mining equipment recovery.

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Parameter optimization and test of hydraulic soil insertion device of orchard gas explosion subsoiling and fertilizing machine

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International Journal of agricultural and Biological Engineering 2023年第2期16卷 132-141页

作者： Congju Shen Lixin Zhang Shouxing Jia Yan Zhou Fan Li Yameng Dai Jing Zhang Wenxiao Ma College of mechanical and Electrical Engineering Shihezi UniversityShihezi 832000XinjiangChina xinjiang academy of agricultural and reclamation science Shihezi 832000XinjiangChina Key Laboratory of Northwest agricultural equipment of Ministry of Agriculture and Rural Affairs Shihezi 832000XinjiangChina

Hydraulic soil insertion device is a key component of orchard gas explosion subsoiling and fertilizing machine to realize rod fixed point soil insertion and gas fertilizer injection into *** order to explore the influence of the main working parameters and structural parameters on the depth and cylinder pressure of the hydraulic insertion device during the insertion process,the working parameters were optimized to ensure the insertion quality and *** this paper,force analysis was performed on the rod insertion process,and key parameter equation of soil insertion resistance was ***-DYNA finite element simulation software was applied to analyze the force variation of the rod during the insertion ***-Behnken test optimization design method and Design-Expert V8.***.6.1 software were used to carry out parameter optimization test of hydraulic insertion device.A multivariate quadratic polynomial regression equation was established by setting the engine revolution,insertion rod diameter and insertion time as independent variables,and the operation parameters of the hydraulic insertion device were optimized based on the relationship between the independent variables and the response *** results showed that the regression equation model based on the response values of insertion depth and cylinder pressure had a good fitting *** engine revolution,rod diameter and insertion time all had significant effects on the increase of insertion depth and decrease of cylinder pressure,with interaction between the engine speed and insertion time with the insertion depth,and interaction between any two factors of engine revolution,rod diameter and insertion time with the cylinder *** influences of the test factors on the insertion depth showed a descending order as engine speed,insertion time,and rod *** influences of the test factors on the cylinder pressure showed a descending order as engine speed,rod diameter,and insertion t

关键词： orchard management machinery subsoiling gas explosion fertilization hydraulic insertion optimization

GhAP1-D3 positively regulates flowering time and early maturity with no yield and fiber quality penalties in upland cotton

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Journal of Integrative Plant Biology 2023年第4期65卷 985-1002页

作者： Caixiang Wang Juanjuan Liu Xiaoyu Xie Ji Wang Qi Ma Pengyun Chen Delong Yang Xiongfeng Ma Fushun Hao Junji Su State Key Laboratory of Aridland Crop science College of Life Science and TechnologyGansu Agricultural UniversityLanzhou 730070China State Key Laboratory of Cotton Biology College of Life ScienceHenan UniversityKaifeng 475004China Cotton research institute Xinjiang Academy of Agricultural and Reclamation ScienceShihezi 832000China State Key Laboratory of Cotton Biology Institute of Cotton Research of Chinese Academy of Agricultural SciencesAnyang 455000China

Flowering time(FTi)is a major factor determining how quickly cotton plants reach *** maturity greatly affects lint yield and fiber quality and is crucial for mechanical harvesting of cotton in northwestern ***,few quantitative trait loci(QTLs)or genes regulating early maturity have been reported in cotton,and the underlying regulatory mechanisms are largely *** this study,we characterized 152,68,and 101 loci that were significantly associated with the three key early maturity traits—FTi,flower and boll period(FBP)and whole growth period(WGP),respectively,via four genome-wide association study methods in upland cotton(Gossypium hirsutum).We focused on one major early maturity-related genomic region containing three single nucleotide polymorphisms on chromosome D03,and determined that GhAP1-D3,a gene homologous to Arabidopsis thaliana APETALA1(AP1),is the causal locus in this *** plants overexpressing GhAP1-D3 showed significantly early flowering and early maturity without penalties for yield and fiber quality compared to wild-type(WT)*** contrast,the mutant lines of GhAP1-D3 generated by genome editing displayed markedly later flowering than the ***1-D3 interacted with GhSOC1(SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1),a pivotal regulator of FTi,both in vitro and in *** in GhAP1-D3 transcript levels clearly affected the expression of multiple key flowering regulatory ***,DNA hypomethylation and high levels of H3K9ac affected strong expression of GhAP1-D3 in early-maturing cotton *** propose that epigenetic modifications modulate GhAP1-D3 expression to positively regulate FTi in cotton through interaction of the encoded GhAP1 with GhSOC1 and affecting the transcription of multiple flowering-related *** findings may also lay a foundation for breeding early-maturing cotton varieties in the future.

关键词： upland cotton early maturity genome‐wide association studies QTL AP1 flowering time

Experiment and optimal design of a collection device for a residual plastic film baler

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Frontiers of agricultural science and Engineering 2015年第4期2卷 347-354页

作者： Qi NIU Xuegeng CHEN Chao JI Jie WU College of Engineering China Agricultural UniversityBeijing 100083China Machinery and equipment research institute Xinjiang Academy of Agriculture and Reclamation SciencesShihezi 832000China College of mechanical and Electrical Engineering Shihezi UniversityShihezi 832002China

It is imperative to carry out research on residual plastic film collection technology to solve the serious problem of farmland *** residual plastic film baler was designed as a package for film strip collection,cleaning and *** collection device is a core component of the *** surface analysis was used in this study to optimize the structure and working parameters for improving the collection efficiency of residual film and the impurity of film *** results show that the factors affecting the collection rate of residual film and the impurity of the film package are the speed ratio(k)between the trash removal roller and eccentric collection mechanism,the number(z)and the mounting angle(θ)of spring teeth in the same revolution *** the collection rate,the importance of the three factors are in the order,k>z>θ.Meanwhile,for the impurity,the importance of three factors are in the order,z>k>θ.When the speed ratio,the mounting angle and the number of spring teeth was set at 1.6°,45°,and 8°,respectively,the collection rate of residual film was 88.9%and the impurity of residual film package was 14.2%for the baler.

关键词： residual film collection device collection rate of residual film impurity of film package optimization baler

Stability mechanism and control of the pumpable supports in longwall recovery room

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International Journal of Mining science and Technology 2024年第7期34卷 957-974页

作者： Zhang, Dong Bai, Jianbiao Zhang, Zizheng Wang, Rui Xu, Ying Fu, Hao Yan, Shuai Deng, Min Liu, Shuaigang State Key Laboratory of Coal Resources and Safe Mining China University of Mining and Technology Xuzhou 221116 China Key Laboratory of xinjiang Coal Resources Green Mining Xinjiang Key Laboratory of Coal-bearing Resources Exploration and Exploitation Xinjiang Engineering Research Center of Green Intelligent Coal Mining Xinjiang Institute of Engineering Urumqi 830023 China Work Safety Key Laboratory on Prevention and Control of Gas and Roof Disasters for Southern Goal Mines Hunan Provincial Key Laboratory of Safe Mining Techniques of Coal Mines Hunan University of Science and Technology Xiangtan 411201 China School of Mines China University of Mining and Technology Xuzhou 221116 China

The load-bearing performance (LBP) of pumpable supports (PPS) is crucial for the stability of longwall pre-driven recovery room (PRR) surrounding rock. However, the unbalanced bearing coefficient (UBC)of the PPS (undertaking unequal load along the mining direction) has not been investigated. A mechanical model of the PRR was established, considering the main roof cantilever beam structure, to derive an assessment formula for the load, the failure criteria, and the UBC of the PPS. Subsequently, the generation mechanisms, and influencing factors of the UBC were revealed. Global sensitivity analysis shows that the main roof hanging length (l2) and the spacing between the PPS (r) significantly impact the UBC. A novel design of the PPS and the coupling control technology were proposed and applied to reduce the UBC of the PPS in the adjacent longwall PRR. Monitor results showed no failure of the PPS at the test site, with the UBC (ζ) reduced to 1.1 consistent with the design value (1.15) basically, fully utilizing the collaborative LBP of the PPS. Finally, the maximum roof-to-floor convergence of the PRR was 234 mm, effectively controlling the stability of the surrounding rock of the PRR and ensuring the mining equipment recovery. © 2024

关键词： Sensitivity analysis

Design and Experiment of 1LFQ-325 Pneumatic Reversible Plough

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Asian agricultural research 2013年第1期5卷 76-78,82页

作者： Xuan ZHENG Xuefeng CHEN Chaomin QIN Li JIAbo JIA Machinery and equipment institute of xinjiang academy of agricultural reclamation sciences xinjiang Tianzhen Farm and Pasture Machinery Manufacturer

A pneumatic reversible plough is developed, which complements to the tractor of 25.7-36.8 *** plough adopts the cylinder as reversing mechanism between the right and left plough bodies, and the cylinder can substitute the mechanical reversing mechanism. The pneumatic turnover allows the plough to be operated easily and turned over flexibly. Field experiment results show that indicators of plough performance meet the requirements of the relevant national standards.

关键词： Pneumatic Reversible plough Design Experiment

Natural aging mechanism of buried polyethylene pipelines during long-term service

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Petroleum science 2023年第5期20卷 3143-3156页

作者： Ying-Chun Chen Yan-Feng Li Yan Xi Qiang Li Qi Lu Jie Yang Beijing University of Technology Beijing100124China xinjiang Inspection institute of Special equipment Urumqi830011XinjiangChina

Currently,accelerated aging tests are widely used to study the aging process of polyethylene ***,this approach can only simulate one or several main influencing factors in the natural environment,which are often quite different from the actual environment of the buried *** this study,five types of PE80 buried pipelines in service for 9e18 years were taken as the research object,while new PE80 pipelines were taken as the reference *** aging process and mechanism of polyethylene buried pipelines were studied through mechanical and chemical property tests and microstructural *** results showed that the pipeline exhibited cross-linking as the main aging mechanism after being in service for 0e18 *** aging degree and law of the inner and outer surface of the pipeline were compared,and the observed mechanism of both surfaces was *** 18 years in service,the elongation at the break of the pipe decreased by 16.2%,and the toughness of the matrix in the main collapse area of the tensile sample was the fundamental reason responsible for changes in the mechanical ***,after 18 years in service,the oxidation induction time of the pipeline was 25.7 min,which was 28.5% higher than the national standard *** were no potential safety hazards during continuous long-term *** results of this paper provide reference data and theoretical guidance for the aging process study of buried polyethylene pipelines.

关键词： Polyethylene Buried pipelines Long-term service Natural aging