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Characterization of bubble behaviors in a dense phase pulsed gas-solid fluidized bed for dry coal processing

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Particuology 2020年第6期18卷 83-91页

作者： Yanjiao Li Fenglong Zhu Yadong Zhang yuemin Zhao Gansu Zhang Qingqing Huang Liang Dong Key Laboratory of Coal Processing and Efficient Utilization Ministry of EducationChina University of Mining&TechnologyXuzhou 221116JiangsuChina School of Chemical Engineering&Technology China University of Mining&TechnologyXuzhou 221116China Department of Mining Engineering West Virginia University1374 Evansdale DriveMorgantown.WV 26506-6070USA

Pulsed gas-solid fluidized beds can effectively separate fine coal,and bubbles play an important role in creating suitable separation *** present study performed statistical and image analyses of the evolution of bubbles in a two-dimensional pulsed gas-solid fluidized bed using a high-speed dynamic *** effects of apparent gas velocity,pulsation frequency and particle size on bubble characteristics and bed expansi on were *** results indicate that,when a fluctuation freque ncy is added,the expa nsion height of the bed in creases,the effect of attachme nt to the bed wall decreases,the leading diameter and rising velocity of the bubbles both decrease and the degree of bubble deformation *** trends are also more obvious for fine *** findings dem on strate that a high density pulsed gas-solid fluidized bed can effectively combine gases and solids to produce a uniform,stable *** bubble diameter and rising velocity were also simulated in the present work,and the relationship between the two was established using a fitting model with an error within 5%.This model provides an effective means of predicting bubble velocity as well as studying the distribution of the bubble phase and improving the stability of the bed density.

关键词： Apparent gas velocity Pulsation frequency Bubble diameter Rising velocity Deformation degree Fluidized bed

Estimation of coal particle size distribution by image segmentation

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International Journal of Mining Science and Technology 2012年第5期22卷 739-744页

作者： Zhang Zelin Yang Jianguo Ding Lihua Zhao yuemin School of Chemical Engineering & Technology China University of Mining & Technology Xuzhou 221116 China

Several industrial coal processes are largely determined by the distribution of particle sizes in their *** these parameters are measured by manual sampling,which is time consuming and cannot provide real time feedback for automatic control *** this paper,an approach using image segmentation on images of overlapped coal particles is *** estimation of the particle size distribution by number is also *** particle overlap problem was solved using image enhancement algorithms that converted those image parts representing material in lower layers to *** high-pass filter(EHPF) algorithms were used to remove the texture from particles on the ***,the edges of the surface particles were identified by morphological edge *** algorithms are described in detail as is the method of extracting the coal particle *** indicate that using more coal images gives a higher accuracy *** positive absolute error of 50 random tests was consistently less than 2.5% and the errors were reduced as the size of the fraction increased.

关键词： Coal size distribution Overlap problem Estimation Feature extraction

△P index with different gas compositions for instantaneous outburst prediction in coal mines

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Mining Science and Technology 2010年第5期20卷 723-726页

作者： WU Dongmei ZHAO yuemin CHENG Yuanping AN Fenghua National Engineering Research Center of Coal Gas Control China University of Mining ＆ Technology Xuzhou 221008 China Key Laboratory of Gas and Fire Control for Coal Mines China University of Mining ＆ Technology Xuzhou 221008 China School of Chemical Engineering and Technology China University of Mining ＆ Technology Xuzhou 221116 China

In this study we measured the △P(initial speed of gas emission) index with different gas concentrations of carbon dioxide(pure CO2,90% CO2+10% CH4,67% CO2+33% CH4,50% CO2+50% CH4,30% CO2+10% CH4 and pure CH4) of coal samples from the No.2 coal seam in the Yaojie Coal Mine,Gansu province,*** effect of carbon dioxide concentration,gas composition,coal strength and particle size of coal samples on the △P index was *** experimental results show that with gas of various compositions,the △P value of three samples were clearly *** △P index of coal samples A,B and C(0.2～0.25 mm) were 4,6 and 7 with pure CH4 and 22,30 and 21 when pure CH4 was *** dioxide concentration affects the △P index *** △P index increases with an increase in carbon dioxide concentration,especially for coal ***,the △P index and K(another outburst index) values tested only with pure CH4 for prediction of the danger of outburst is not *** is important to determine the initial speed of gas emission given the gas composition of the coal seam to be tested for exact outburst prediction.

关键词： prediction △P index outbursts coal mining gas composition carbon dioxide

益母草碱调节RhoA/ROCK信号通路对冠心病大鼠主动脉内皮细胞损伤的影响

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河北医学 2024年第8期30卷 1272-1279页

作者：郭艳红谢月敏冯强郭少英王静河北省邯郸市中心医院河北邯郸056000

目的:研究益母草碱(Leo)通过调节Ras同源基因家族成员A(RhoA)/Rho相关的卷曲螺旋激酶(ROCK)信号通路对冠心病(CHD)大鼠主动脉内皮细胞损伤的影响及机制。方法:将造模成功的75只CHD大鼠随机分为模型组(CHD组)、Leo低、中、高剂量组(Leo-... 详细信息

目的:研究益母草碱(Leo)通过调节Ras同源基因家族成员A(RhoA)/Rho相关的卷曲螺旋激酶(ROCK)信号通路对冠心病(CHD)大鼠主动脉内皮细胞损伤的影响及机制。方法:将造模成功的75只CHD大鼠随机分为模型组(CHD组)、Leo低、中、高剂量组(Leo-L组、Leo-M组、Leo-H组)和Leo高剂量组+RhoA激活剂LPA组(Leo-H+LPA组),每组15只。Leo-L、Leo-M、Leo-H组分别灌胃15、30、60mg·kg^(-1)·d^(-1)的Leo,Leo-H+LPA组灌胃60mg·kg^(-1)·d^(-1)的Leo,另需腹腔注射1mg·kg^(-1)·d^(-1)的LPA,Control组和CHD组以相同方式给予等量生理盐水,均连续干预4周。超声心动图测定心功能指标;全自动生化分析仪测定总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)水平;酶联免疫吸附测定(ELISA)检测白细胞介素6(IL-6)、肿瘤坏死因子α(TNF-α)、一氧化氮(NO)、内皮素1(ET-1)、内皮细胞特异性分子-1(EMS1)、血管内皮细胞粘附分子1(VCAM-1)水平;苏木精-伊红(HE)染色观察主动脉内皮损伤;流式细胞仪检测主动脉内皮细胞凋亡;免疫印迹法(Western blot)检测RhoA/ROCK信号通路相关蛋白表达。结果:与Control组相比,CHD组主动脉壁增厚且染色不均匀,细胞膨大,排列紊乱,内皮粗糙;左室舒张末期内径(LVEDD)、左室收缩末期内径(LVESD)、TC、TG、LDL-C、IL-6、TNF-α、ET-1、VCAM-1和EMS1水平、细胞凋亡率及RhoA、ROCK1和ROCK2蛋白表达显著升高(P<0.05),左室射血分数(LVEF)、缩短分数(FS)、HDL-C、NO水平显著降低(P<0.05)。与CHD组相比,Leo-L组、Leo-M组、Leo-H组主动脉染色均匀,动脉壁结构清晰,细胞排列紧密且形态较正常,内膜较平滑;LVEDD、LVESD、TC、TG、LDL-C、IL-6、TNF-α、ET-1、VCAM-1和EMS1水平、细胞凋亡率及RhoA、ROCK1和ROCK2蛋白表达逐渐降低(P<0.05),LVEF、FS、HDL-C、NO水平逐渐升高(P<0.05)。Leo-H+LPA组逆转了Leo对CHD大鼠的保护作用(P<0.05)。结论:Leo可能通过抑制RhoA/ROCK信号通路改善CHD大鼠心功能,降低血脂,抑制炎症,进而减轻CHD大鼠主动脉内皮细胞损伤。

关键词：益母草碱 RhoA/ROCK信号通路冠心病内皮细胞损伤血脂炎症反应

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实验室样品委托管理要点

山东交通科技 2024年第2期 149-151页

作者：宋兰平侯跃敏钟世兴山东省交通科学研究院山东济南250031

样品管理是实验室开展检测任务和样品流转关键环节,样品接收人员一方面要了解实验室的资质认定范围,掌握实验室的质量管理体系,另一方面要对资质认定范围内的各产品性能、方法标准等有一定认识,能够根据委托方描述,判断其需求,并给予一... 详细信息

样品管理是实验室开展检测任务和样品流转关键环节,样品接收人员一方面要了解实验室的资质认定范围,掌握实验室的质量管理体系,另一方面要对资质认定范围内的各产品性能、方法标准等有一定认识,能够根据委托方描述,判断其需求,并给予一定指导,从而准确、高效地完成样品委托办理和流转工作。

关键词：委托管理唯一性标识样品流转

Separation performance of fine low-rank coal by vibrated gas-solid fluidized bed for dry coal beneficiation

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Particuology 2015年第6期13卷 100-108页

作者： Jingfeng He yuemin Zhao Jie Zhao Zhenfu Luo Chenlong Duan Yaqun He School of Chemical Engineering and Technology Chino University of Mining and Technology Xuzhou 221116 China

Vibrational energy was introduced to a dense medium gas-solid fluidized bed to improve the separation performance of 1-6 mm fine low-rank coal. The setup was termed a vibrated gas-solid fluidized bed and could provide a stable fluidization state and uniform density distribution for dry coal beneficiation by the transfer of vibrational energy and the interaction between vibrations and the gas phase. Favorable segregation of the ash content of the 1-6-ram-sized lignite samples is achieved under suitable operating conditions. Higher yields of cleaning coal were acquired when the ash content was reduced. The probable error values were 0.065 and 0.055 at separating densities of 1.68 and 1.75 g/clTl3 for the 1-3- and 3-6-mm- sized lignite samples, respectively. Effective beneficiation of 1-6-ram-sized fine lignite could be achieved using the vibrated gas-solid fluidized bed, which provides an alternative technique for the separation of fine low-rank coal in arid areas.

关键词： Lignite Vibrational energyGas-solid fluidized bedSegregationSeparation performance

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空间运动康复训练设备设计及运动仿真

机械设计与制造工程 2024年第9期53卷 1-6页

作者：张文靖张孟新侯悦民北京信息科技大学机电工程学院北京100192

针对脑卒中患者提出了一种依照人机工程学设计的空间运动康复训练设备。首先对康复训练设备进行了正运动学分析,并在MATLAB中描绘出空间运动云图。然后根据患者在日常生活中的基本动作,分别对上肢和下肢进行了各运动关节轨迹规划,绘制... 详细信息

针对脑卒中患者提出了一种依照人机工程学设计的空间运动康复训练设备。首先对康复训练设备进行了正运动学分析,并在MATLAB中描绘出空间运动云图。然后根据患者在日常生活中的基本动作,分别对上肢和下肢进行了各运动关节轨迹规划,绘制了各个关节在不同运动轨迹中的角速度、角加速度变化曲线和相应的轨迹曲线。该康复设备的创新点在于结合上下肢运动特性,与针对单一上肢或下肢进行训练的设备相比,扩大了运动范围,增加了运动自由度,结构更加简单易安装。

关键词：康复设备人机工程运动学运动规划结构设计运动仿真

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Effects of substituting chemical fertilizers with manure on rice yield and soil labile nitrogen in paddy fields of China: A meta-analysis

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Pedosphere 2023年第1期33卷 172-184页

作者： Qiong HOU yuemin NI Shan HUANG Ting ZUO Jian WANG Wuzhong NI College of Environmental and Resource Sciences Zhejiang UniversityZhejiang Provincial Key Laboratory of Agricultural Resources and EnvironmentHangzhou 310058China Agricultural Experimental Station Zhejiang UniversityHangzhou 310058China

Substituting chemical fertilizers with manure is an important method for efficient nutrient management in rice cropping systems of *** nitrogen(N)is the most active component of the soil N pool and plays an essential role in soil ***,the effects of manure substitution on soil labile N in rice cropping systems and their relationships with soil properties,fertilization practices,and climatic conditions remain unclear and should be systematically ***,we investigated rice grain yield and four types of soil labile N that have been widely reported,including available nitrogen(AN),ammonium nitrogen(NH_(4)^(+)-N),nitrate nitrogen(NO_(3)^(−)-N),and microbial biomass nitrogen(MBN).We reviewed 187 published articles and performed a meta-analysis to quantify the effects of manure substitution on yield and soil labile *** results showed that manure substitution increased AN,MBN,NH+4-N,and NO−3-N by 11.3%,38.5%,5.9%,and 8.1%,*** substitution significantly increased the yield by 1.4%–5.9%,but full substitution significantly decreased the yield by 2.9%.The positive effects of manure substitution on yield and AN were stronger with long-term *** differences in responses varied across specific manure types,N application rates,soil properties,and climatic *** conclusion,manure substitution can increase soil labile N and is regarded as an efficient strategy for improving soil N fertility and a recommended measure for applying both chemical and organic fertilizers in rice *** study provides evidence of the effects of manure substitution on yield enhancement by increasing soil labile N.

关键词： available nitrogen climatic factors fertilization practices manure substitution microbial biomass nitrogen soil properties

CFD-DEM simulation of fluid-solid flow of a tapered column separation bed

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International Journal of Mining Science and Technology 2015年第5期25卷 855-859页

作者： Duan Chenlong Sheng Cheng Wu Lingling Zhao yuemin He Jinfeng School of Chemical Engineering and Technology China University of Mining & Technology

Research on recycling waste Printed Circuit Boards(PCB) is at the forefront of preventing environmental pollution and finding ways to recycle *** Tapered Column Separation Bed(TCSB) is invented aiming at disposing the problem that fine particles of waste printed circuit boards cannot be separated efficiently so as to obtain further insight about the underlying mechanisms and demonstrate the separation feasibility in the tapered column separation *** this work,a Computational Fluid Dynamics(CFD) coupled with Discrete Element Method(DEM) model for two-phase flow has been extended to simulate the fluid-solid flow in the tapered column separation *** validity is demonstrated by its successful capturing the key features of particles' flow pattern,velocity,the pressure distribution,the axial position with time and axial force for particles with different *** results show that the plastic particles and resin particles become overflow,while copper particles,iron particles and aluminum particles successively become underflow,with a discharge water flow rate of 1 m^3/h,an obliquity of 30°.The simulated results agree reasonably well with the experimental *** this equipment to separate waste PCBs is feasible,theoretically.

关键词： Tapered column separation bed Waste printed circuit boards Computational fluid dynamics Discrete element method Fluid-solid flow