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有限元法分析不同固定方式在胫骨远端粉碎性骨折骨愈合中的生物力学差异

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中国组织工程研究 2024年第24期28卷 3814-3821页

作者：颜华东张中赵刚李杰宋华孙建华刘志王明明济宁医学院附属滕州市中心人民医院骨科山东省滕州市277599 山东大学山东省济南市250100 济南市中心医院骨科山东省济南市250013

背景:胫骨远端粉碎性骨折伴软组织损伤的治疗具有挑战性,新型逆行胫骨髓内钉、外置接骨板是重要的治疗手段,但其在骨折愈合不同时期、不同负重情况时的骨折端应变、应力遮挡情况未见报道。目的:通过有限元分析法探讨骨折愈合不同时期逆... 详细信息

背景:胫骨远端粉碎性骨折伴软组织损伤的治疗具有挑战性,新型逆行胫骨髓内钉、外置接骨板是重要的治疗手段,但其在骨折愈合不同时期、不同负重情况时的骨折端应变、应力遮挡情况未见报道。目的:通过有限元分析法探讨骨折愈合不同时期逆行髓内钉及外置接骨板的生物力学差异,为临床应用及康复锻炼提供科学参考。方法:利用1名40岁健康男性的胫骨CT数据,建立胫骨远端粉碎骨折的有限元模型,构建胫骨逆行髓内钉、外置接骨板固定模型及骨痂模型并根据骨折的固定原则进行装配。使用ANSYS软件进行有限元分析,比较骨折愈合不同时期时逆行髓内钉及外置接骨板2种固定方式的骨折端位移、胫骨应力遮挡、骨痂应力、胫骨及固定装置应力分布情况。结果与结论:①胫骨骨折端相对位移随着骨折愈合的进行逐渐减小,在术后3个月后位移明显减少;术后0,1个月,外置接骨板组的垂直位移及总位移均大于逆行髓内钉组,2种固定方式的Z轴位移(水平内外侧位移)均较X、Y轴位移明显,且接骨板模型的Z轴位移差异最明显;2种固定方式的Z轴位移最大位置均位于胫骨外侧,位移最小位置均位于胫骨内侧;②骨折愈合的应力遮挡率随骨折时间延长而逐渐降低;逆行髓内钉的应力遮挡率在骨折愈合不同时期均高于外置接骨板;术后3个月后外置接骨板的应力遮挡率降低到4%左右,逆行髓内钉的应力遮挡率降低到40%左右;③2种固定方式骨痂应力集中部位的应力随着载荷的增大而增加,外置接骨板组骨痂的应力始终大于逆行髓内钉组;2种固定方式中,骨痂最大应力大致分布一致,均位于胫骨外侧部分;④随着骨折愈合2种固定方式的胫骨最大应力逐渐降低,外置接骨板组的应力始终大于逆行髓内钉组;1500 N载荷下外置接骨板组胫骨最大应力区域平均应力为285 MPa,而逆行髓内钉组为26 MPa;⑤随着骨折愈合2种固定模型中固定装置的应力逐渐降低,外置接骨板组的应力均明显高于逆行髓内钉组;术后3个月以后,2种固定装置的应力下降幅度明显变缓;⑥提示在骨折愈合早期,胫骨逆行髓内钉组中骨折端应变小、胫骨最大应力适中,允许早期负重;外置接骨板组骨折端存在应变过大、胫骨最大应力过大,需在保护下部分负重、不能完全负重;在骨折愈合中后期,胫骨逆行髓内钉及外置接骨板组均可完全负重,接骨板的应力遮挡率明显低于胫骨逆行髓内钉。

关键词：胫骨远端骨折骨痂骨折愈合逆行髓内钉外置接骨板有限元分析生物力学应力遮挡

Numerical Analysis of Labyrinth Seal Performance for the Impeller Backface Cavity of a Supercritical CO_(2) Radial Inflow Turbine

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Computer Modeling in Engineering & Sciences 2021年第3期126卷 935-953页

作者： Jinguang yang Feng zhao Min Zhang yan Liu Xiaofang Wang School of Energy and Power Dalian University of TechnologyDalianChina

For a radial inflow turbine(RIT),leakage flow in impeller backface cavity has critical impacts on aerodynamic performance of the RIT and axial force acting on the RIT *** order to control this leakage flow,different types of labyrinth seals are numerically studied in this paper based on a supercritical carbon dioxide(S-CO_(2))*** effects of seal clearance and cavity outlet pressure are first analyzed,and the impacts of seal design parameters,including height,number and shape of seal teeth,are *** indicate that adding labyrinth seal can improve cavity pressure and hence adequately inhibits leakage *** the seal clearance and increasing the height of seal teeth are beneficial to improve sealing performance,and the same effect can be obtained by increasing the number of seal ***,employing seals can reduce leakage loss and improve RIT efficiency under a specific range of cavity outlet ***,the influences of seal types on the flow field in seal cavity are numerically analyzed,and results demonstrate that isosceles trapezoidal type of seal cavity has better sealing performance than triangular,rectangular and right-angled trapezoidal seal cavities.

关键词： Supercritical carbon dioxide radial inflow turbine impeller backface cavity labyrinth seal CFD simulation

Long-Term Loading Test of Reinforced Glulam Beam

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Journal of Renewable Materials 2022年第1期10卷 183-201页

作者： Nan Guo Jing Ren Ling Li yan zhao Mingtao Wu College of Civil Engineering Northeast Forestry UniversityHarbin150040China School of Civil Engineering and Architecture Wuyi UniversityWuyishan354300China

Due to creep characteristics of wood,long-term loading can cause a significant stress loss of steel bars in rein-forced glulam beams and high long-term deflection of the beam *** this study,15 glulam beams were subjected to a 90-day long-term loading test,and the effects of long-term loading value,reinforcement ratio and prestress level on the stress of steel bars,midspan long-term deflection,and other parameters were compared and *** main conclusions drawn from this study were that the long-term deflection of the reinforced glulam beams accounted for 22.5%,20.6%,and 18.2%of the total deflection respectively when the loading value was 20%,30%,and 40%of the estimated ultimate load under the long-term *** higher the loading level was,the smaller the proportion of the long-term deflection in the total deflection *** with ordinary glulam beams,the long-term deflection of the reinforced glulam beam was even *** the condition of the constant loading level,the total stress value of the steel bars decreased by 17.5%,13.6%,and 9.1%,and the proportion of the long-term deflection of the beam midspan in the total deflection was 26.9%,24.2%,and 20.6%respectively when the reinforcement ratio was 2.05%,2.68%,and 3.39%.With the increase of the reinfor-cement ratio,the stress loss of the steel bars decreased,and the proportion of the long-term deflection decreased as *** other conditions remained constant and the prestress level of the steel bars was 0 MPa,30 MPa,and 60 MPa,the total stress value of the steel bars decreased by 9.1%,9.4%,and 10.2%,respectively,and the propor-tion of the long-term deflection in the total deflection was 20.6%,26.1%,and 64.9%,*** the increase of the prestress value,the stress loss of the steel bars increased,and the proportion of the long-term deflection increased as well.

关键词： Reinforced glulam beams long-term loading tests creep characteristics prestress total stress of steel bars

基于RFID的总装车间车身冗余识别系统设计

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机电工程技术 2024年第6期53卷 122-125页

作者：王志远牛焱赵俊涛北京奔驰汽车有限公司北京100176

柔性化是当前汽车主机厂所普遍采取的生产策略,条形码技术作为车身识别的手段在该策略中起着举足轻重的作用。然而由于条形码质量问题导致的识别系统可靠性较低的问题给生产活动带来了困扰和挑战。为了提高车身识别成功率从而提高汽车... 详细信息

柔性化是当前汽车主机厂所普遍采取的生产策略,条形码技术作为车身识别的手段在该策略中起着举足轻重的作用。然而由于条形码质量问题导致的识别系统可靠性较低的问题给生产活动带来了困扰和挑战。为了提高车身识别成功率从而提高汽车装配线的生产效率,研究了提高数字化控制系统可靠性的问题,创新性地提出了基于RFID识别系统冗余设计的解决方案。对导致控制系统可靠性降低的条形码识别失效进行了分析,对RFID系统设计进行了阐述,最终给出优化后的冗余系统程序流程。该系统的应用有效地提高了控制系统可靠性及汽车装配线的生产效率,取得了良好的经济效果,具备一定的示范效应。

关键词：条形码 RFID 冗余自动化系统集成现场总线汽车制造

Preparation and electrochemical performance of double perovskite La_2CoMnO_6 nanofibers

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International Journal of Minerals,Metallurgy and Materials 2018年第8期25卷 950-956页

作者： Jie Fu Heng-yan zhao Jie-run Wang Yu Shen Ming Liu College of Environmental and Chemical Engineering Dalian Jiaotong University

Through electrospinning,La_2Co Mn O_6 nanofibers were prepared from a polyvinylpyrrolidone/lanthanum nitrate–cobalt acetate–manganese acetate(PVP/LCM)precursor and were used as electrode *** morphologies and structures of the samples were characterized by field-emission scanning electron microscopy(FE-SEM),transmission electron microscopy(TEM),X-ray diffraction(XRD),and Brunauer-Emmett-Teller(BET)specific surface area *** results show that the prepared La_2Co Mn O_6 nanofibers are stable,one-dimensional structures formed from interconnected La_2Co Mn O_(6 )nanoparticles with a diamond-like crystal *** specific surface area of the fibers is 79.407 m^2·g^(-1).Electrochemical performance tests with a three-electrode system reveal the specific capacitance of the La_2Co Mn O_6 nanofibers as 109.7 F·g^(-1) at a current density of 0.5 A·g^(-1).After 1000 charge-discharge cycles at a current density of 1 A·g^(-1),the specific capacitance maintains 90.9%of its initial value,demonstrating a promising performance of the constraint capacitance and good cyclic stability.

关键词： electrospinning double perovskite super capacitor electrode materials

Droplet Motion and Phase Change Model with Two-Way Coupling

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Journal of Thermal Science 2019年第4期28卷 826-833页

作者： zhao Fulong LIU Qianfeng yan Xiao BO Hanliang ZENG Chen TAN Sichao College of Nuclear Science and Technology Harbin Engineering UniversityHarbin 150001China Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China

The droplet interacts intensively with surrounding gas when moving and evaporating in the gas,of which the mutual effects of the gas and the evaporating droplet need to be taken into *** the typical droplet model,the gas parameters are usually considered as that at infinity and the local parameter variation surrounding the droplet is neglected,consequently leading to some *** research tries to develop a new moving droplet phase change model with two-phase coupling which characterizes the local parameter variation of gas phase surrounding the evaporating ***,the interaction mechanism of two phases is presented based on the droplet evaporation ***,the droplet motion and phase change model is developed through the theoretical ***,the analysis of the evaporation characteristics of the injected droplets in the hot air is conducted to simulate the operation process of the containment spray system in the nuclear power *** numerical simulation indicates the refined droplet model is more capable for precise prediction of the situations with large quantities of evaporating droplets and with intensive interactions between two phases.

关键词： droplet evaporate heat and mass transfer two-way coupling local parameter

基于边缘计算的森林防火视频低功耗终端设计与探索

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森林防火 2024年第3期42卷 20-24页

作者：赵艳香王明初李杰北京市园林绿化大数据中心北京100118

针对北京林区供电供网困难、森林防火视频监控数据存储占用空间大、人工识别率低等问题,运用深度卷积模型,设计了具备实时监测、自动识别、按需回传、低功耗的森林防火视频终端盒子,可在森林防火视频终端自动监测、识别、报警、回传疑... 详细信息

针对北京林区供电供网困难、森林防火视频监控数据存储占用空间大、人工识别率低等问题,运用深度卷积模型,设计了具备实时监测、自动识别、按需回传、低功耗的森林防火视频终端盒子,可在森林防火视频终端自动监测、识别、报警、回传疑似火情等图像,自动过滤掉90%以上重复、无效视频图像,节约存储资源,减少人工成本。

关键词：低功耗边缘计算深度卷积神经网络分时运行机制事件驱动机制

Effects of nicotinamide and riboflavin on the biodesulfurization activity of dibenzothiophene by Rhodococcus erythropolis USTB-03

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Journal of Environmental Sciences 2008年第5期20卷 613-618页

作者： yan Hai SUN Xudong XU Qianqian MA zhao XIAO Chengbin Ning Jun Department of Biological Science and Technology School of Applied Science University of Science and Technology Beijing Beijing 100083 China Research Center for Eco-environmental Science Chinese Academy of Sciences Beijing 100085 China

Rhodococcus erythropolis USTB-03 is a promising bacterial strain for the biodesulfurization of dibenzothiophene （DBT） via a sulfurspecific pathway in which DBT is converted to 2-hydroxybiphenyl （2HBP） as an end product. The effects of nicotinamide and riboflavin on the sulfur specific activity （SA） of DBT biodesulfurization by R. erythropolis USTB-03 were investigated. Both nicotinamide and riboflavin were found to enhance the expression of SA, which was not previously reported. When R. erythropolis USTB-03 was grown on a medium containing nicotinamide of 10.0 mmol or riboflavin of 50.0 μmol, SA was raised from 68.0 or so to more than 130 mmol 2HBP/（kg dry cells.h）. When R. erythropolis USTB-03 was grown in the presence of both nicotinamide of 5.0 mmol and riboflavin of 25.0 μmol, SA was further increased to 159.0 mmol 2HBP/（kg dry cells.h）. It is suggested that the biological synthesis of reduced form of flavin mononucleotide （FMNH2）, an essential coenzyme for the activities of biodesulfurization enzyme Dsz C and A, might be enhanced by nicotinamide and riboflavin, which was responsible for the increased SA of R. erythropolis USTB-03.

关键词： biodesulfurization dibenzothiophene nicotinamide Rhodococcus erythropolis USTB-03 riboflavin

热轧2250mm加热炉炉顶壁面传热-应力耦合模型模拟研究

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宝钢技术 2024年第2期 26-29页

作者：张俊张雪荣赵雁王琳宝山钢铁股份有限公司武汉钢铁有限公司湖北武汉430083 宝山钢铁股份有限公司中央研究院湖北武汉430080

为减少热轧加热炉表面的热损失,采用纳米材料能够降低加热炉炉顶温度,起到节能降耗的效果,但纳米材料如何铺设是个难题。通过建立加热炉的几何模型,确定加热炉有限元计算的热力学边界和力学边界;通过加热炉有限元分析,确定加热炉的分层... 详细信息

为减少热轧加热炉表面的热损失,采用纳米材料能够降低加热炉炉顶温度,起到节能降耗的效果,但纳米材料如何铺设是个难题。通过建立加热炉的几何模型,确定加热炉有限元计算的热力学边界和力学边界;通过加热炉有限元分析,确定加热炉的分层温度变化情况和应力变化情况,为纳米材料的应用提供数值依据。

关键词：加热炉模型纳米材料