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Thermoelectric properties of (GeTe)_(1-x)[(Ag_(2)Te)_(0.4)(Sb_(2)Te_(3))_(0.6)]_(x) alloys

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Rare Metals 2022年第3期41卷 921-930页

作者： Hong-Xia Liu Xin-Yue Zhang Zhong-Lin Bu Wen Li Yan-Zhong pei School of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan 030024China Laboratory of Magnetic and Electric Functional Materials and the Applications The Key Laboratory of Shanxi ProvinceTaiyuan 030024China Interdisciplinary Materials Research Center School of Materials Science and EngineeringTongji UniversityShanghai 201804China

The(GeTe)_(x)(AgSbTe_(2))_(100-x)alloys(TAGS-x)have been demonstrated as a promising p-type candidate for thermoelectric applications,attracting numerous atten-tions on the advancements of thermoelectric *** of carrier concentration for optimizing ther-moelectric performance in TAGS can be achieved by varying the ratio of Ag to Sb,and the Ag/Sb ratio of~2/3 has been proven as the optimal ***,this work focuses on the systematic investigation on ther-moelectric properties of(GeTe)_(1-x)[(Ag_(2)Te)_(0.4)(Sb_(2)Te_(3))_(0.6)]_(x) *** crystal structure for the alloys transfers from rhombohedral to cubic at room temperature as x≥*** evolution of band parameter is estimated using a single parabolic band(SPB)model with acoustic phonon *** density of states effective mass increases with x increasing,which leads to an enhancement of Seebeck coefficient along with a reduction in Hall mobility due to the additional carrier scattering by point ***-while,the lattice thermal conductivity of lower than~0.7 W·m^(-1)·K^(-1) in the entire temperature range and the lowest one of only 0.45 W·m^(-1)·K^(-1) is achieved due to additional phonon scattering by point *** a result,a peak thermoelectric figure of merit(zT)of~1.80 and an average one of~1.37 in 300–800 K are realized in non-stoichiometric TAGS alloys here.

关键词： Thermoelectric Tellurium-antimonygermanium-silver(TAGS) Crystal structure Lattice thermal conductivity

3D打印导板技术联合多次去旋转治疗重度僵硬性脊柱侧凸

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中国组织工程研究 2024年第6期28卷 922-926页

作者：张之栋祁家龙裴少保马力王善松刘艺明合肥市第一人民医院脊柱外科安徽省合肥市230061

背景:近年来,随着3D打印技术的发展,使得外科手术走向个性化、精准化。3D打印导板技术可实现术前规划、术中导航,使得外科手术更加精准。临床中重度僵硬性脊柱侧弯矫形术中仍面临置钉准确性不高导致螺钉松动甚至引起神经并发症的问题,... 详细信息

背景:近年来,随着3D打印技术的发展,使得外科手术走向个性化、精准化。3D打印导板技术可实现术前规划、术中导航,使得外科手术更加精准。临床中重度僵硬性脊柱侧弯矫形术中仍面临置钉准确性不高导致螺钉松动甚至引起神经并发症的问题,现有关于3D打印导板技术指导重度僵硬性脊柱侧弯术中置钉的研究不多。目的:评价3D打印导向模板技术联合后路多次去旋转治疗重度僵硬性脊柱侧凸的临床效果。方法:回顾性分析3D打印导向模板椎弓根螺钉置入后联合施行后路多次转棒去旋转技术治疗重度脊柱侧凸6例患者的临床资料,男3例,女3例,手术时年龄15-23岁,平均(18.17±3.49)岁。分析术后2周和术后18个月时脊柱侧弯相关参数的变化,进行统计学分析。结果与结论:(1)手术时间280-540 min,平均(340.83±102.20)min,术中出血量1000-4000 mL,平均(2000.00±1073.70)mL,固定节段9-14个椎体,平均(11.83±1.72)个椎体,矫形过程中未出现螺钉松动;(2)所有患者均获得随访,术后2周全脊柱正侧位片显示冠状位主弯的cobb角、冠状面C_(7)铅垂线和S1正中线的距离、矢状面C_(7)铅垂线和S1后缘的距离、顶椎偏移、胸椎后凸角、腰椎前凸角均获得明显矫正,主弯的cobb角平均矫正率62.22%,术后18个月随访各参数较术后2周无明显变化,矫形效果满意,无感染和内固定断裂;(3)围术期切口延迟愈合1例,经过换药处理瘢痕愈合,未出现神经并发症;(4)结果表明3D打印导向模板结合后路多次转棒去旋转技术治疗重度僵硬性脊柱侧凸畸形安全有效,矫形效果满意。

关键词：重度僵硬性脊柱侧凸去旋转 3D打印导板技术肋骨切除术 CT三维重建

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同轴空间相机铝蜂窝夹层主承力板设计

计算机仿真 2024年第6期41卷 71-76页

作者：袁健裴思宇霍占伟张雷长光卫星技术股份有限公司吉林长春130033 东北大学辽宁沈阳110819

为某型号同轴空间相机设计了具有铝蜂窝夹层结构的轻量化主承力板。从加固结构和预埋件两方面改良传统蜂窝夹层,上下碳纤维面板选用M40J,铺层方式为[0°/45°/90°/-45°]s,铝蜂窝芯子规格为3×0.05mm,主承力板设计重量为3.98kg。采用... 详细信息

为某型号同轴空间相机设计了具有铝蜂窝夹层结构的轻量化主承力板。从加固结构和预埋件两方面改良传统蜂窝夹层,上下碳纤维面板选用M40J,铺层方式为[0°/45°/90°/-45°]s,铝蜂窝芯子规格为3×0.05mm,主承力板设计重量为3.98kg。采用基于正交各向异性实体单元的蜂窝夹层结构等效建模方法,将铝蜂窝芯子等效为“中间层”,仿真分析结果表明,主要空间工况下主次镜间的相对位移不超过9.904μm,相对转角不超过4.708″,对应相机调制传递函数最小值为0.252,较设计值仅下降约2%,整机基频达到94.4Hz,相机动、静力学特性能够满足可见光波段遥感器设计要求。

关键词：空间光学蜂窝夹层结构主承力板等效建模方法空间环境适应能力

Optimization of submerged entry nozzle parameters for ultra-high casting speed continuous casting mold of billet

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Journal of Iron and Steel Research International 2022年第1期29卷 44-52页

作者： pei Xu Yong-zhi Zhou Deng-fu Chen Mu-jun Long Hua-mei Duan Laboratory of Metallurgy and Materials College of Materials Science and EngineeringChongqing UniversityChongqing 400044China Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and New Materials Chongqing UniversityChongqing 400044China

Controlling the flow behavior in the mold in an appropriate way is the basis for realizing the billet ultra-high speed continuous *** on the new proposed physical water modeling experiment considering the effects of solidified shell and hydrostatic pressure,the flow behavior in the mold with cross section of 160 mm 9160 mm during continuous casting of billet is regulated by optimizing the inner diameters and immersion depths of submerged entry nozzle at the ultra-high casting speeds of 5.0–6.5 m/*** results show that under the premise of no slag entrainment,as well as uniform coverage and keeping good fluidity of liquid slag layer on the top free surface of the fluid in the mold,the appropriate parameters of submerged entry nozzle under the ultra-high casting speed of billet are 50 mm in inner diameter,95 mm in outer diameter and 180 mm in immersion *** on the basis of the obtained parameters of submerged entry nozzle,it can be known that the reasonable ranges of level fluctuation and impacting depth of the stream in the mold are about 0.82-1.11 and 593-617 mm,respectively.

关键词： Ultra-high casting speed Billet continuous casting Submerged entry nozzle Physical water modeling Flow behavior

条件自动驾驶接管与高速公路出口小半径匝道平面线形匹配性研究

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中国公路学报 2024年第9期37卷 236-249页

作者：林子鉴陈丰马小翔潘晓东陈培焱袁华智同济大学道路与交通工程教育部重点实验室上海201804 西南交通大学交通运输与物流学院四川成都611756 上海市园林设计研究总院有限公司建筑环境院上海200030 兰州理工大学土木工程学院甘肃兰州730050

为了解自动驾驶接管后驾驶人行为与现有高速公路出口小半径匝道平面线形的匹配性,基于驾驶模拟仿真平台构建高速公路出口接管场景并进行驾驶模拟试验。以驾驶模式(手动驾驶,接管)、匝道圆曲线半径(50、70、90 m)与匝道交通流密度(每车道... 详细信息

为了解自动驾驶接管后驾驶人行为与现有高速公路出口小半径匝道平面线形的匹配性,基于驾驶模拟仿真平台构建高速公路出口接管场景并进行驾驶模拟试验。以驾驶模式(手动驾驶,接管)、匝道圆曲线半径(50、70、90 m)与匝道交通流密度(每车道5、45 pcu·km^(-1))作为自变量,构建12种驾驶模拟场景。招募30名被试进行驾驶模拟试验,记录试验过程中驾驶人的眼动特征及车辆运动状态。选取瞳孔直径、水平视角分布标准差、垂向视角分布标准差、平均纵向速度变化率、横向偏移量标准差、最小碰撞时间(TTC)共6项指标,分析检验不同因素对各指标影响的显著性。依据检验结果选取指标构建匹配性模糊综合评价模型,对不同匝道半径与交通流密度组合下的接管匹配性进行评估。研究结果表明:相比手动驾驶场景,接管场景中驾驶人瞳孔直径变大,视点水平方向离散程度增加,车辆纵、横向行驶稳定性降低;随匝道半径增加、交通流密度减小,驾驶人瞳孔直径减小,车辆纵向行驶稳定性增加,匝道半径的变化对车辆运动状态的影响比对驾驶人视觉行为的影响更大。在交通流密度为每车道45 pcu·km^(-1)的场景中,增加匝道半径对接管匹配性的提升存在边际递减效应,且较小匝道半径与较高交通流密度的组合会放大各自对接管匹配性的不利影响。当交通流密度较低(每车道5 pcu·km^(-1))时,即使匝道半径取设计极限值,接管匹配性也可达到“高”;而当交通流密度较高(每车道45 pcu·km^(-1))时,匝道半径需接近目前实际工程应用中的最高标准,方可使接管匹配性达到“高”。基于接管匹配性分级,从人、车、路多角度进行考虑提出接管策略优化建议,以提升驾驶人的接管绩效。研究结果对于提升高速公路出口段自动驾驶车辆接管过程的安全性具有指导作用。

关键词：交通工程接管绩效驾驶模拟试验自动驾驶道路线形

Influences of rock fragments on the hydraulics and erosion of concentrated runoff in steep spoil heaps on the Loess Plateau of China

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International Journal of Sediment Research 2022年第5期37卷 553-562页

作者： Wenzhao Guo Hongliang Kang Xiao Yu Wenlong Wang pei Tian State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Water and Soil Conservation Northwest Agriculture & Forestry University Key Laboratory for Geographical Process Analysis & Simulation of Hubei Province Central China Normal University

The soil-rock mixed spoil heaps are prone to severe soil erosion during heavy rain, causing severe land degradation and ecological and environmental damage. Nevertheless, past research on the erosion on spoil heaps has focused on soil particles that were readily eroded and disregarded the rock fragments(RF) that were not readily eroded. To explore the effect of the RF embedded in spoil heaps on the hydraulics of and erosion caused by concentrated runoff, scour-erosion experiments were implemented on three types of spoil heaps: RF = 7%, RF = 45%, and RF = 69%. The RF clearly reduced runoff and erosion on steep spoil heaps. As the RF increased from 7% to 69%, the runoff intensity and runoff coefficient decreased by 72.9%-79.1% and 83.2%-84.1% respectively, and the sediment concentration, soil denudation rate, and total soil loss decreased by 36.0%-47.8%, 83.7%-87.1%, and 87.0%-92.3%, *** rills were generated during the experiments, and the RF distinctly influenced the rill characteristics. High contents of RF restrained rill retreating and undercutting, and promoted rill widening. With an increase in RF, the flow shear stress and stream power gradually decreased, and the Darcy-Weisbach roughness coefficient increased. These findings imply that the RF dissipated the flow energy and reduced soil detachment capacity and sediment transport capacity. Soil detachment is strongly related to the Darcy-Weisbach roughness coefficient, Reynolds number, and runoff intensity,which may be the preferred descriptors of soil detachment. The current findings indicate that embedded rock fragments could effectively reduce soil loss on steep spoil heaps.

关键词： Soil erosion Runoff Rock fragments (RF) Rills Chinese loess plateau

经额入路神经内镜手术在慢性硬膜下血肿治疗中的应用

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中国内镜杂志 2024年第1期30卷 1-6页

作者：龚益杨文魁陈沛翟冬煜云南省第三人民医院神经外科云南昆明650011

目的评价经额入路神经内镜手术治疗慢性硬膜下血肿(CSDH)的疗效。方法分析80例CSDH病例的临床资料,依据手术方式,分为传统顶结节钻孔外引流术组(钻孔引流组,n=40),以及经额入路神经内镜下小骨窗血肿清除术组(神经内镜组,n=40),比较两组... 详细信息

目的评价经额入路神经内镜手术治疗慢性硬膜下血肿(CSDH)的疗效。方法分析80例CSDH病例的临床资料,依据手术方式,分为传统顶结节钻孔外引流术组(钻孔引流组,n=40),以及经额入路神经内镜下小骨窗血肿清除术组(神经内镜组,n=40),比较两组患者治疗有效率、术后1个月血肿复发率、手术时间和术中出血量。结果神经内镜组治疗有效率为95.0%,明显高于钻孔引流组的75.0%,神经内镜组术后1个月血肿复发率为5.0%,明显低于钻孔引流组的25.0%,神经内镜组手术时间为(54.1±7.5)min,较钻孔引流组的(40.7±9.4)min长,差异均有统计学意义(P0.05)。结论采用经额入路神经内镜手术治疗CSDH,能明显提高手术疗效,且术后血肿复发率极低。值得应用于临床。

关键词：慢性硬膜下血肿神经内镜经额入路钻孔引流术手术

城市轨道交通全自动运行车辆移动值乘辅助系统研究与应用

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铁道通信信号 2024年第2期60卷 19-24页

作者：裴加富包亮强林立张炳锋卡斯柯信号有限公司上海200070

针对全自动运行车辆值乘岗位责任重大,但配套设备智能化、数字化水平不高的现状,基于全自动运行车辆、列控等专业系统关键设备运行状态数据,研究全自动运行车辆移动值乘辅助系统构建方案,以提升全自动运行车辆值乘水平和应急故障排除效... 详细信息

针对全自动运行车辆值乘岗位责任重大,但配套设备智能化、数字化水平不高的现状,基于全自动运行车辆、列控等专业系统关键设备运行状态数据,研究全自动运行车辆移动值乘辅助系统构建方案,以提升全自动运行车辆值乘水平和应急故障排除效率。通过分析全自动运行线路车辆值乘人员的核心需求,研究实时数据库、故障智能诊断等关键技术,最终依托LTE综合承载网,实现全自动运行车辆移动化实时监督、故障智能分析和故障排查指导等功能。实际应用表明:该方案可有效提高车辆值乘人员应急故障排查效率,进一步保障和提升全自动运行线路的运营安全,为城市轨道交通数字化、智能化运营提供参考。

关键词：全自动运行移动值乘多岗位协同智能分析故障排查智能化运营

Design and modeling of continuum robot based on virtual-center of motion mechanism

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机械工程前沿:英文版 2023年第2期18卷 143-159页

作者： Guoxin LI Jingjun YU Yichao TANG Jie PAN Shengge CAO Xu pei School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China Beijing Special Engineering Design and Research Institute Beijing 100143China

Continuum robot has attracted extensive attention since its *** has multi-degree of freedom and high compliance,which give it significant advantages when traveling and operating in narrow *** flexural virtual-center of motion(VCM)mechanism can be machined integrally,and this way eliminates the assembly between ***,it is well suited for use as a continuum robot ***,a design method for continuum robots based on the VCM mechanism is proposed in this ***,a novel VCM mechanism is formed using a double leaf-type isosceles-trapezoidal flexural pivot(D-LITFP),which is composed of a series of superimposed LITFPs,to enlarge its ***,the pseudo-rigid body(PRB)model of the leaf is extended to the VCM mechanism,and the stiffness and stroke of the D-LITFP are ***,the VCM mechanism is combined to form a flexural joint suitable for the continuum ***,experiments and simulations are used to validate the accuracy and validity of the PRB model by analyzing the performance(stiffness and stroke)of the VCM ***,the motion performance of the designed continuum robot is *** show that the maximum stroke of the VCM mechanism is approximately 14.2°,the axial compressive strength is approximately 1915 N/mm,and the repeatable positioning accuracies of the continuum robot is approximately±1.47°(bending angle)and±2.46°(bending direction).

关键词： VCM mechanism continuum robot flexural joint pseudo-rigid body model cable-driven