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基于EDEM的驱动耙旋耕装置的分析与试验

农机化研究 2025年第3期47卷 16-21页

作者：董成李想尚书旗王东伟何晓宁李绪李墨贤王如正青岛农业大学机电工程学院山东青岛266109

为提高动力驱动耙碎土过程中的效率和碎土率,在现有结构基础上,分析了动力耙耙刀碎土原理,构建了碎土耙刀-土壤动力学模型,并对动力驱动耙刀具长度和角度进行设计。同时,利用EDEM软件以动力驱动耙耙刀转动速度、耙刀外倾角度、耙刀长度... 详细信息

为提高动力驱动耙碎土过程中的效率和碎土率,在现有结构基础上,分析了动力耙耙刀碎土原理,构建了碎土耙刀-土壤动力学模型,并对动力驱动耙刀具长度和角度进行设计。同时,利用EDEM软件以动力驱动耙耙刀转动速度、耙刀外倾角度、耙刀长度为影响因素,以碎土率为检测指标,进行响应面仿真分析试验。试验结果表明:耙刀转动速度对碎土率影响极显著,耙刀外倾角和长度对碎土率影响比较显著;耙刀倾角为34.7°、耙刀转速为320 r/min、耙刀长度为28 cm时,耙刀装置处于最优工作状态。研究结果可为动力驱动耙的开发研究提供参考。

关键词：动力驱动耙 EDEM 耙刀-土壤动力学模型碎土率

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Petrophysical parameters inversion for heavy oil reservoir based on a laboratory-calibrated frequency-variant rock-physics model

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Petroleum Science 2023年第6期20卷 3400-3410页

作者： Xu Han shang-Xu Wang Zheng-Yu-cheng Zhang Hao-Jie Liu Guo-Hua Wei Gen-Yang Tang CNPC Key Laboratory of Geophysical Prospecting China University of Petroleum(Beijing)Beijing102249China Engineering Research Center of the Ministry of Education for Exploration and Development of Complex Oil and Gas Reservoirs China University of Petroleum(Beijing)Beijing102249China Shengli Oilfield Geophysical Exploration Research Institute SinopecDongying257000ShandongChina

Heavy oil has high density and viscosity, and exhibits viscoelasticity. Gassmann's theory is not suitable for materials saturated with viscoelastic fluids. Directly applying such model leads to unreliable results for seismic inversion of heavy oil reservoir. To describe the viscoelastic behavior of heavy oil, we modeled the elastic properties of heavy oil with varying viscosity and frequency using the Cole-Cole-Maxwell (CCM) model. Then, we used a CCoherent Potential Approximation (CPA) instead of the Gassmann equations to account for the fluid effect, by extending the single-phase fluid condition to two-phase fluid (heavy oil and water) condition, so that partial saturation of heavy oil can be considered. This rock physics model establishes the relationship between the elastic modulus of reservoir rock and viscosity, frequency and saturation. The viscosity of the heavy oil and the elastic moduli and porosity of typical reservoir rock samples were measured in laboratory, which were used for calibration of the rock physics model. The well-calibrated frequency-variant CPA model was applied to the prediction of the P- and S-wave velocities in the seismic frequency range (1–100 Hz) and the inversion of petrophysical parameters for a heavy oil reservoir. The pre-stack inversion results of elastic parameters are improved compared with those results using the CPA model in the sonic logging frequency (∼10 kHz), or conventional rock physics model such as the Xu-Payne model. In addition, the inversion of the porosity of the reservoir was conducted with the simulated annealing method, and the result fits reasonably well with the logging curve and depicts the location of the heavy oil reservoir on the time slice. The application of the laboratory-calibrated CPA model provides better results with the velocity dispersion correction, suggesting the important role of accurate frequency dependent rock physics models in the seismic prediction of heavy oil reservoirs.

关键词： Heavy oil Rock physics Velocity dispersion Pre-stack inversion Reservoir prediction

Eradication of Helicobacter pylori increases childhood growth and serum acylated ghrelin levels

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World Journal of Gastroenterology 2012年第21期18卷 2674-2681页

作者： Yao-Jong Yang Bor-Shyang Sheu Hsiao-Bai Yang cheng-Chan Lu ching-Chun Chuang Departments of Pediatrics and Institute ofClinical Medicine Medical College National Cheng Kung Uni-versity Tainan 70428 Taiwan China Departments of Internal Medicine and In-stitute of Clinical Medicine Medical College National ChengKung University Tainan 70428 Taiwan China Ton-Yen General Hospital Hsinchu County70428 Taiwan China Department of Pathology Medical College National Cheng Kung University Tainan70428 Taiwan China Institute of Clinical Medicine MedicalCollege National Cheng Kung University Tainan 70428 Tai-wan China

AIM: To determine whether Helicobacter pylori (H. pylori)infected children have reduced body weight (BW) and height (BH) growth, and if H. pylori eradication may restore growth while improving serum acylated ghrelin. METHODS: This longitudinal cohort study with oneyear follow-up enrolled 1222 children aged 4 to 12 years old into an observation cohort (18 with and 318 without H. pylori ) and intervention cohort (75 with and 811 without). The 7-d triple therapy was used for eradication in the intervention cohort. The net increases of BW and BH as well serum acylated ghrelin after oneyear follow-up were compared between successful eradicated H. pylori-infected children and controls. RESULTS: In the observation cohort, the H. pylori - infected children had lower z score of BW (-1.11 ± 0.47 vs 0.35 ± 0.69, P = 0.01) and body mass index (BMI) (0.06 ± 0.45 vs 0.44 ± 0.73, P = 0.02) at enrollment and lower net BW gain after one-year follow-up (3.3 ± 2.1 kg vs 4.5 ± 2.4 kg, P = 0.04) than the non-infected controls. In the intervention cohort, the H. pylori - infected children had lower z score of BMI (0.25 ± 1.09 vs 0.68 ± 0.87, P = 0.009) and serum acylated ghrelin levels (41.8 ± 35.6 pg/mL vs 83.6 ± 24.2 pg/mL, P < 0.001) than the non-infected controls. In addition to restoring decreased serum ghrelin levels (87.7 ± 38.0 pg/mL vs 44.2 ± 39.0 pg/mL, P < 0.001), the H. pylori - infected children with successful eradication had higher net gains (P < 0.05) and increase of z scores (P < 0.05) of both BW and BH as compared with non-infected controls after one-year follow-up. CONCLUSION:H. pylori-infected children are associated with low serum acylated ghrelin and growth retardation. Successful eradication of H. pylori restores ghrelin levels and increases growth in children.

关键词： Child Clinical trial Ghrelin Growth retardation Helicobacter pylori

Effect of Carbon Content on Mechanical Properties and Weather Resistance of High Performance Bridge Steels

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Journal of Iron and Steel Research International 2009年第6期16卷 63-69页

作者： GUO Jia shang cheng-jia YANG Shan-wu WANG Ying WANG Lian-wei HE Xin-lai Material Science and Engineering School University of Science and Technology Beijing Beijing 100083 China Metallurgical and Ecological Engineering School University of Science and Technology Beijing Beijing 100083 China

The influence of carbon content on the mechanical properties of high yield strength bridge steel has been in- vestigated. The results show that the excellent mechanical properties and corrosion resistance are obtained for the steel with carbon content of 0.03% -0. 05% （mass percent）. According to the results, a new weathering bridge steel plate with carbon content of 0. 045% （mass percent） has been developed. The appropriate controlled cooling process should be taken due to the results of CCT （continuous cooling transformation） and TTT （time-temperature-transformation） to ensure both microstructure and mechanical properties. CCT curve of the newly developed steel shows that when accelerated cooling speed is higher than 5 ℃/s, the intermediate transformation products can be formed. The TTT curve displays that the intermediate transformation temperature ranges from 600 to 530 ℃. Yield strength of the newly developed steels reaches 500 MPa, and their elongation and toughness are excellent.

关键词： low-carbon bridge steel weathering steel intermediate transformation

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实时Web图形应用中的选择性场景传输

计算机集成制造系统 2006年第4期12卷 636-640页

作者：唐敏英正明 CHOU shang-ching 董金祥浙江大学CAD&CG国家重点实验室浙江杭州310027 Wichita州立大学计算机系勘萨斯州威奇托67220

为了解决实时Web图形应用中大型场景数据传输所需时间长的问题,提出一种选择性场景传输算法。通过对需要传输的模型和纹理信息的最终显示贡献进行定量分析,给出了每个对象或每个面片的视觉重要性的度量,并在此基础上设计了选择性传输场... 详细信息

为了解决实时Web图形应用中大型场景数据传输所需时间长的问题,提出一种选择性场景传输算法。通过对需要传输的模型和纹理信息的最终显示贡献进行定量分析,给出了每个对象或每个面片的视觉重要性的度量,并在此基础上设计了选择性传输场景中模型和纹理的算法,给出了基于图形硬件绘制方法的实现。原型系统的实验结果表明,该方法可以在保持用户图形质量的同时减少等待时间,并作为一个有力的工具来提升实时Web图形应用的性能。

关键词：实时Web图形应用场景传输层次细节渐进网格

Design of B/N Co-doped micro/meso porous carbon electrodes from CNF/BNNS/ZIF-8 nanocomposites for advanced supercapacitors

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Journal of Bioresources and Bioproducts 2023年第3期8卷 292-305页

作者： Zhen shang Xingye An Shuangxi Nie Na Li Haibing Cao Zhengbai cheng Hongbin Liu Yonghao Ni Liqin Liu Tianjin Key Laboratory of Pulp and Paper Tianjin University of Science and TechnologyTianjin 300457China Guangxi Key Laboratory of Clean Pulp&Papermaking and Pollution Control College of Light Industry and Food EngineeringGuangxi UniversityNanning 530004China Department of Chemical Engineering University of New BrunswickFredericton NB E3B 5A3Canada Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China Zhejiang Jingxing Paper Co. Ltd.Pinghu 314214China

Boron(B)and nitrogen(N)co-doped 3D hierarchical micro/meso porous carbon(BNPC)were successfully fabricated from cellulose nanofiber(CNF)/boron nitride nanosheets(BNNS)/zinc-methylimidazolate framework-8(ZIF-8)nanocomposites prepared by 2D BNNS,ZIF-8 nanoparticles,and wheat straw based ***,CNF/ZIF-8 acts as versatile skeleton and imparts partial N dopant into porous carbon structure,while the introduced BNNS can help strengthen the hierarchical porous superstructure and endow abundant B/N co-dopants within BNPC *** obtained BNPC electrode possesses a high specific surface area of 505.4 m2/g,high B/N co-doping content,and desirable *** assembled with BNPC-2(B/N co-doped porous carbon with a CNF/BNNS mass ratio of 1꞉2)electrodes exhibited exceptional electrochemical performance,demonstrating high capacitance stability even after 5000 charge-discharge *** devices exhibited outstanding energy density and power density,as well as the highest specific capacitance of 433.4 F/g at 1.0 A/g,when compared with other similar *** study proposes a facile and sustainable strategy for efficiently fabrication of rich B/N co-doped hierarchical micro/meso porous carbon electrodes from agricultural waste biomass for advanced supercapacitor performance.

关键词： Cellulose nanofiber Zeolitic imidazolate framework Hexagonal boron nitride nanosheets B/N co-dopants Hierarchical structure Supercapacitor

Physical Simulation and Experimental Examination of ε-Cu Particles Dissolution Evolution During Welding of Copper Precipitation Strengthening Steel

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Journal of Iron and Steel Research International 2007年第6期14卷 58-62页

作者： WANG Qing-feng shang cheng-jia CHEN Da-wei CAI Jian-wei CHEN Wei-chang State Key Laboratory of Metastable Materials Science and Technology Yanshan University Qinhuangdao 066004 Hebei China Department of Materials Physics University of Science and Technology Beijing Beijing 100083 China Dynamic Systems Inc Poestenkill NY12140 USA DSI-YSU Joint Laboratory of Physical Simulation on Materials Processing Yanshan University Qinhuangdao 066004 Hebei China

The kinetics of ε-Cu particles dissolution in the matrix during welding of a copper-precipitation strengthening steel was determined by a combination of GleebleTM physical simulation, TEM examination and hardness meas urement. The ε-Cu particles underwent a coarsening and part dissolution and then complete dissolution reaction as the peak temperature increased from 750 to 1 000℃, which resulted in the decrease in the number density of ε-Cu particles and hardness in the heat affected zone （HAZ）. The results can be used to understand the evolution of this transformation and a softening behavior of the HAZ during welding of this type of steel.

关键词： ε-Cu particle dissolution hardness kinetics steel welding physical simulation

Study on antibacterial mechanism of electron beam radiation on Aspergillus flavus

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Food Bioscience 2023年第1期51卷 288-296页

作者： Linlin Fan Lili Li Feifei shang Yuhua Xie Zhenhua Duan Qianwei cheng Yuqiao Zhang College of Biological and Chemical Engineering Guangxi University of Science and TechnologyLiuzhou545006China School of Food and Bioengineering/Institute of Food Science and Engineering Technology Hezhou UniversityHezhouGuangxi548299China

Contamination with Aspergillus flavus,which produces carcinogenic metabolites,during the post-harvest storage of agricultural products seriously endangers human health and *** this study,the efficacy of short-term electron beam irradiation processing with high sterilization efficiency,no contamination and no additives was evaluated for the prevention and control of *** effects of irradiation on Aspergillus growth were determined based on analyses of physical and chemical indexes,morphology,mycelial growth,spore germination rates,mycelial dry weights,and toxin-producing *** effects of irradiation on the cell membrane and cell wall of *** were investigated based on assays of the chitin content,chitinase activity,protein concentration,and malondialdehyde *** to the antioxidant system was determined by the hydrogen peroxide content,catalase activity,superoxide dismutase activity,superoxide anion radical scavenging activity and rates of 1,1-diphenyl-2-trinitrophenylhydrazine *** inhibitory effect of irradiation on peanut invasion by *** was *** irradiation,the thallus morphology was destroyed,mycelial growth was inhibited,and the spore germination rate,mycelial dry weight,and toxin-producing ability of *** were *** activity and the malondialdehyde content increased,while the chitin and total protein contents *** activity,superoxide dismutase activity,superoxide anion radical scavenging activity,and the rate of 1,1-diphenyl-2-trinitrophenylhydrazine inhibition decreased,while the hydrogen peroxide content increased after *** findings suggested that electron beam irradiation can effectively inhibit the normal growth and toxin production of *** increased cell membrane permeability and decreased the integrity of the cell *** antioxidant system was damaged to some *** with that in unirradiated ***,high-dose electron beam irra

关键词： Aspergillus flavus Electron beam irradiation Antibacterial mechanism Aflatoxin B1

The effect of applied voltages on the structure,apatite-inducing ability and antibacterial ability of micro arc oxidation coating formed on titanium surface

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Bioactive Materials 2018年第4期3卷 426-433页

作者： Qing Du Daqing Wei Yaming Wang Su cheng shang Liu Yu Zhou Dechang Jia Institute for Advanced Ceramics Department of Materials Science and EngineeringHarbin Institute of TechnologyHarbin150001China Key Laboratory of Advanced Structural-Functional Integration Materials&Green Manufacturing Technology Harbin Institute of TechnologyHarbin150001China Center of Analysis and Measurement Harbin Institute of TechnologyHarbin150001China Department of Mechanical Engineering School of Architecture and Civil EngineeringHarbin University of Science and TechnologyHarbin150001China

The micro arc oxidation(MAO)coatings with different concentrations of Ca,P and Zn elements are successfully formed on the titanium substrate at the different applied *** MAO treatment,the MAO coating exhibits the porous surface structure and composed of anatase and rutile TiO2 ***,the average size and density of micro-pores on the MAO coatings have been modified via the adjusting the applied *** addition,the contents of the incorporated elements such as Zn,Ca and P elements in the MAO coatings have been *** bonding strength test results reveal that the MAO coating shows higher bonding strength,which is up to 45±5 *** to the pure Ti plate,the MAO coating formed at 350 and 400 V show good apatite-inducing ***,the MAO coating containing Zn,Ca and P elements have better antibacterial ability for *** and ***,the incorporation of Zn,Ca and P elements was an effective method to improve the antibacterial ***,the concentrations of Zn,Ca and P elements could be adjusted with the changing of the applied *** a result,the enhancement of the antibacterial ability on the MAO coating surfaces was depended on the comprehensive effect of the incorporated elements and the surface property of MAO coatings.

关键词： Micro arc oxidation Zn element Applied voltage Apatite-inducing ability Antibacterial ability