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Microstructures and Properties of NiCrBSi/WC Biomimetic Coatings Prepared by Plasma Spray Welding

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Journal of Bionic Engineering 2015年第4期12卷 592-603页

作者： Shiming Huang Daqian Sun Desheng xu wenquan Wang Hongyong xu Key Laboratory of Automobile Materials of Ministry of Education School of Materials Science and Engineering Jilin University Changchun 130022 China

The NiCrBSi/WC biomimetic coatings were prepared on the low carbon steel substrate by plasma spray welding with mixed powders （WC-Col2＋NiCrBSi） based on the bionic principles, and the coating characteristics were investigated. The results indicate that the coatings have a full metallurgical bond in coating/substrate interface, and consist mainly ofy-Ni, WC, Cr23C6, Cr7C3, Ni3Si, CrsB3, and FeNi3 phases. The powder composition influences the microstructures and properties of the coatings. The WC content and the hardness of coatings increase with the mass fraction of WC-Co 12 powder. The biomimetic coatings have much higher wear resistance compared with the low carbon steel, which is attributed to the combination of hard WC and chromium carbide particles （bionic units） and soft y-Ni matrix in the coatings. It is favorable to prepare the biomimetic coating by plasma spray welding with the mixed powders （20wt%WC-Col2＋80wt%NiCrBSi） for improving the wear resis- tance of the coating.

关键词： plasma spray welding biomimetic coatings mixed powders microstructures properties

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基于PFC的放顶煤放煤机理数值模拟

陕西煤炭 2024年第2期43卷 6-11页

作者：尹建辉徐文全耿耀强陕西煤业化工技术研究院有限责任公司陕西西安710065 渭南陕煤启辰科技有限公司陕西渭南714000 煤炭绿色安全高效开采国家地方联合工程研究中心陕西西安710065

基于PFC颗粒流数值模拟软件,分别模拟了0.6 m、1.2 m、1.8 m这3种放煤步距,结果显示这3种放煤步距放出率分别为86%、83%、74%,含矸率分别为12%、6%、2%。从顶煤的运动特征和接触力场变化规律论述了放煤动态多层位拱结构的发育过程及机理... 详细信息

基于PFC颗粒流数值模拟软件,分别模拟了0.6 m、1.2 m、1.8 m这3种放煤步距,结果显示这3种放煤步距放出率分别为86%、83%、74%,含矸率分别为12%、6%、2%。从顶煤的运动特征和接触力场变化规律论述了放煤动态多层位拱结构的发育过程及机理,发现顶煤的放出过程是一个多层位拱结构不断形成、破坏的动态过程,会形成一个动态多层位拱结构;而不同位置的顶煤运移空间受限程度不同,导致不同位置顶煤运动状态不同,当拱结构上方矿山压力大于拱结构内顶煤颗粒之间摩擦力时,拱结构遭到破坏;由于位于拱顶的顶煤运移速度远大于两侧拱脚,导致拱结构的拱顶层位不断向上发育,从而形成高层位的拱结构,涌向放煤口的顶煤可能在放煤口形成低层位的拱结构。研究认为,沿工作面走向顶煤放出体应是一个连续的放煤椭球体,合理的放煤步距应为一个椭球体的宽度,并通过模拟试验证明了通过支架尾梁摆动破拱能够有效提高放煤效率。

关键词：放顶煤放煤步距顶煤成拱放煤机理拱结构

高校工会助推高等教育高质量发展存在的问题与对策——基于对山东高校工会的调查

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北京市工会干部学院学报 2024年第2期39卷 1-8页

作者：宋国栋赵文钰徐文劝齐鲁工业大学/山东科学院济南250353

教育强国建设进程中,高校工会应强化教育职能担当,发挥自身资源优势,助推高等教育高质量发展。本文通过对山东高校工会助推本省高等教育高质量发展的基本现状进行客观调查,发现高校工会助推高等教育高质量发展中存在顶层设计不完善、思... 详细信息

教育强国建设进程中,高校工会应强化教育职能担当,发挥自身资源优势,助推高等教育高质量发展。本文通过对山东高校工会助推本省高等教育高质量发展的基本现状进行客观调查,发现高校工会助推高等教育高质量发展中存在顶层设计不完善、思想认识不到位、工作举措不得力、干部素质不过硬、会员参与不积极的问题,针对以上问题提出了应深化教育体制改革、提升教育工作认识、创新教育工作方式、打造教育共同体、牵手优质教育机构的对策。

关键词：高校工会高等教育高质量发展

Energy dissipation of coal and rock during damage and failure process based on EMR

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International Journal of Mining Science and Technology 2015年第5期25卷 787-795页

作者： Song Dazhao Wang Enyuan Li Zhonghui Liu Jie xu wenquan School of Safety Engineering China University of Mining & Technology Postdoctoral Research Station Yongcheng Coal & Electricity Holding Group Co.Ltd. State Key Laboratory of Coal Resources & Safe Mining Shaanxi Coal and Chemical Technology Institute Co. Ltd.

The physical and mechanical change processes of coal and rock are closely related to energy transformation,and the destruction and failure of coal and rock is an instability phenomena driven by energy ***,the energy change of large-scale coal rock in the mine site is hardly calculated accurately,making it difficult to monitor coal-rock systematic failure and collapse from the perspective of *** the energy dissipation EMR monitoring system,we studied the damage and failure of coal and rock with bursting liability from the energy dissipation point using the geophysical method-EMR,and explored the energy dissipation characteristics during uniaxial compression and their main influencing *** results show that under displacement-control loading mode,there are 2 types of energy dissipation trends for both coal and rock with bursting *** type Ⅰ trend is a steady increase one during the whole process,therein,the energy dissipation of rock samples is accelerated at the peak *** type Ⅱ trend energy is a W-shaped fluctuating one containing 6 *** load-control loading mode,there is one energy dissipation trend of shock downward-steady *** that,rock samples also present a trend of 4 *** energy dissipation characteristics of coal and rockduring loading failure process can be used as effective criteria to assess whether they are in a stable or destructive *** factors influencing energy dissipation in the loading failure process of coal and rock mainly include strength,homogeneity,and energy input efficiency.

关键词： Energy dissipation Electromagnetic radiation Coal and rock Damage and failure Rock burst

不同年龄不同性别儿童足底压力分布特征对比研究

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体育科学研究 2024年第4期28卷 49-54页

作者：徐文泉冯玲崔广泽胡宗祥北京航空航天大学体育部北京100191 北京市海淀区实验小学北京100037 首都体育学院体育教育训练学院北京100191 集美大学体育学院福建厦门361021

取XX小学100名7岁和10岁男女学生儿童为研究对象,通过Footscan平板系统对儿童进行站立和步行的足底压力数据采集,使用单因素方差分析对数据进行统计,深入了解儿童足底压力分布特征,对比其左右脚差异、年龄差异以及性别差异。结果表明:... 详细信息

取XX小学100名7岁和10岁男女学生儿童为研究对象,通过Footscan平板系统对儿童进行站立和步行的足底压力数据采集,使用单因素方差分析对数据进行统计,深入了解儿童足底压力分布特征,对比其左右脚差异、年龄差异以及性别差异。结果表明:静态站立时儿童重心落在足后区,一般在右后区,且10岁较7岁儿童静态中重心控制更好;儿童动态足底压力中,前足所受冲量最大,足跟次之,中足最小;前足中跖骨区所受冲量较大;从最大压强来看,足跟区受力最大,跖骨区受力大小大致表现为M3>M2>M5>M1>M4;且年龄增大,足跟区和第三跖骨区受力增大,女生比男生表现更为明显;儿童步态不均衡,中足区和足跟区的左右差异大,主要表现为左脚中足区各特征值大于右脚,而在足跟区各值小于右脚,且女生表现更为明显。结论:7岁较10岁儿童足跟过渡更快,步频快,同年龄段女生较男生更接近于成人动态足底压力情况。

关键词：儿童足底压力步态

Distribution pattern of front abutment pressure of fully-mechanized working face of soft coal isolated island

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International Journal of Mining Science and Technology 2012年第2期22卷 279-284页

作者： xu wenquan Wang Enyua Shen Rongxi Song Dazhao Zhang Jingmin School of Safety Engineering China University of Mining&TechnologyXuzhou 221116China State Key Laboratory of Coal Resources and Mine Safety xuzhou 221-008.China

The front abutment pressure of a fully-mechanized workface of 11061 soft coal isolated island of Liangbei Coal Mine was measured and studied using a self-developed mining-induced stress monitoring system associated with electromagnetic radiation technology, and the effects of abutment pressure distribution on strata behavior we discussed. The results indicate that the miningdnduced influencing distance advanced at the fully-mechanized working face of soft coal isolated island is larger than that at the gen- eral working face at the isolated island, besides the fracture zone in front of working face was widened to some extent, and the influencing range caused by relaxations on both roadways became bigger with the advancing working face. Moreover, it can be indicated that mining has significant effect on strata behav- ior of fully-mechanized working face of soft coal isolated island, which is mostly distributed in the area of stress concentration. The research results have an important reference value for revealing the distribution pattern of the front abutment pressure of a fully-mechanized working face of soft coal isolated island, and controlling the coal-rock dynamic disaster occurrence under similar mining conditions.

关键词： Soft coalIsolated islandFully-mechanized working faceAbutment pressureCoal-rock dynamic disaster

中长跑运动员穿不同鞋垫跑步时的足底压力探究

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体育科研 2024年第5期45卷 63-71页

作者：徐文泉冯玲崔广泽孙雨苗北京航空航天大学体育部北京100191 北京市海淀区实验小学北京100037 首都体育学院北京100191

目的:选取参与训练与教学课程的27名中长跑运动员,通过在相同速度下穿着不同类型鞋垫跑步时的实验测试,揭示跑步时足底压力、压强生物力学参数指标特征,为中长跑运动员提供生物力学的理论依据。方法:采用实验法、文献资料法、专家访谈... 详细信息

目的:选取参与训练与教学课程的27名中长跑运动员,通过在相同速度下穿着不同类型鞋垫跑步时的实验测试,揭示跑步时足底压力、压强生物力学参数指标特征,为中长跑运动员提供生物力学的理论依据。方法:采用实验法、文献资料法、专家访谈法、数理统计法,利用足底压力测试系统与处理软件进行数据整理分析。结果:中长跑运动员穿着不同类型测试鞋垫跑步时左脚和右脚足底平均压力、最大压强在8个分布区域情况不一,两两对比重复测量方差分析存在不同差异,表现为足跟区是跑步时落地缓冲阶段足部主要的受力区域。结论:①无鞋垫时,左、右脚的M2、M4、M5、M6区足底压力均大于其他3种鞋垫;而无鞋垫时足底除M3区外,其他区域内的足底压强均大于其他3种鞋垫。②M5(第2~4跖骨区)、M6(第1跖骨区)是跑步蹬地发力阶段主要受力区域。M1(足跟区)是跑步时落地缓冲阶段足部主要的受力区域。③无鞋垫时,左、右脚的M2、M5、M6区的足底压力值以及左、右脚的M2、M4、M5、M6区的最大压强值均与其他3种鞋垫存在显著性差异。④足底压力值和足底压强值显示A型鞋垫在减压、抗震方面的功能较好。

关键词：中长跑运动员足底压力鞋垫

Laparoscopic versus open surgery in treating patients with gallbladder cancer: a systematic review and meta-analysis

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Hepatobiliary Surgery and Nutrition 2024年第3期13卷 444-459,I0012-I0014页

作者： Duo Li Li xu Xiangling Deng Yongliang Sun Zihuan Zhang Tianxiao Wang Ruili Wei Yingjixing Luo wenquan Niu Zhiying Yang Graduate School Peking Union Medical College and Chinese Academy of Medical SciencesBeijingChina Department of General Surgery China-Japan Friendship HospitalBeijingChina Graduate School Beijing University of Chinese MedicineBeijingChina Department of Pediatrics China-Japan Friendship HospitalBeijingChina Graduate School Peking University Health Science CenterBeijingChina Graduate School Capital Medical UniversityBeijingChina Center for Evidence-Based Medicine Capital Institute of PediatricsBeijingChina

Background:Concerns over the security of laparoscopic radical operation for gallbladder cancer(GBC)*** systematic review and meta-analysis attempted to compare the safety and efficacy of laparoscopic surgery(LS)versus open surgery(OS)in the treatment of ***:The PubMed,EMBASE,and Web of Science were searched from inception to July 18,*** search,quality assessment,and data extraction were completed independently and in ***-size estimates expressed as weighted mean difference(WMD)or odds ratio(OR)with 95%confidence interval(CI)were derived under the random-effects ***:A total of 27 independent studies including 2,868 participants were *** was noted for intraoperative blood loss(WMD:−117.194,95%CI:−170.188 to 64.201,P<0.001),harvested lymph nodes(WMD:−1.023,95%CI:−1.776 to−0.269,P=0.008),postoperative hospital stay(WMD:−3.555,95%CI:−4.509 to−2.601,P<0.001),postoperative morbidity(OR:0.596,95%CI:0.407 to 0.871,P=0.008),overall survival rate at 2-year(OR:1.524,95%CI:1.143 to 2.031,P=0.004),T2 survival at 1-year(OR:1.799,95%CI:1.777 to 2.749,P<0.01)and 2-year(OR:2.026,95%CI:1.392 to 2.949,P<0.001),as well as T3 survival at 1-year(OR:2.669,95%CI:1.564 to 4.555,P<0.001)and 2-year(OR:2.300,95%CI:1.308 to 4.046,P=0.004).Subgroup analyses revealed that ethnicity,incidental GBC,sample size,and follow-up period were possible sources of *** was a low probability of publication bias for all outcomes except postoperative ***:Our findings indicated that LS statistically had better 2-year survival rates,less intraoperative bleeding,shorter hospitalization times,and lower rates of complications than ***,the superiority and even the safety of LS still remain an open question due to the impact of incidental GBC,unaccounted heterogeneity,publication bias,lymph node dissection,and port-site metastasis.

关键词： Systematic review and meta-analysis gallbladder cancer(GBC) laparoscopic surgery(LS) open surgery survival

等离子喷焊原位生成TiC硬质增强镍基耐磨层组织与性能

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金属学报 2016年第11期52卷 1423-1431页

作者：徐红勇王文权黄诗铭程祥霞任美璇吉林大学材料科学与工程学院汽车材料教育部重点实验室长春130022 大连交通大学材料科学与工程学院大连116028 同济大学材料科学与工程学院上海200092 东北电力大学电力工程学院吉林132012

通过等离子喷焊NiCrBSi+Ti混合粉末制备TiC硬质增强镍基复合耐磨层,利用OM,SEM,XRD及EDS研究了喷焊层微观组织、物相及元素组成特征,并利用显微硬度仪及磨料磨损试验机对喷焊层显微硬度及耐磨料磨损性能进行测试.结果表明,NiCrBSi+Ti混... 详细信息

通过等离子喷焊NiCrBSi+Ti混合粉末制备TiC硬质增强镍基复合耐磨层,利用OM,SEM,XRD及EDS研究了喷焊层微观组织、物相及元素组成特征,并利用显微硬度仪及磨料磨损试验机对喷焊层显微硬度及耐磨料磨损性能进行测试.结果表明,NiCrBSi+Ti混合粉末喷焊层主要包括由保留有共晶组织形态的(γ-Ni+β_1-Ni_3Si)与过共析组织(α-Fe+FeNi_3)组成的基体相,以及镶嵌于基体中的M_7C_3和M_(23)C_6等硬质相;CrB弥散分布于喷焊层中;原位生成的TiC一部分作为M_7C_3和M_(23)C_6等后析出相的形核核心,一部分以细小颗粒(1μm)块体.Ti的加入,显著细化了喷焊层组织,Ti添加量为6%时,喷焊层性能最好,显微硬度可达800 HV_(0.5),磨损质量约为14.5 mg,耐磨性为纯NiCrBSi喷焊层的2倍以上.

关键词： TiC 等离子喷焊原位生成组织与性能