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锚杆加固作用下椭圆形深埋隧洞承载力分析

山东大学学报（工学版） 2024年第1期54卷 131-140页

作者：郝艳广徐建升明道贵雷霆邱明喜陈迪杨中交二航局建筑科技有限公司湖北武汉430050 山东科技大学土木工程与建筑学院山东青岛266590 山东大学(齐河)新材料与智能装备研究院山东德州251100

考虑施工过程中大跨度开挖、锚杆的影响等现场实际情况,分别研究椭圆形隧洞承载能力锚杆长度、锚杆数量、锚杆预应力、侧压力系数以及塑性区范围的变化规律。基于平面弹性复变函数的方法,得到围岩任意一点的应力分量表达式,结合摩尔-库... 详细信息

考虑施工过程中大跨度开挖、锚杆的影响等现场实际情况,分别研究椭圆形隧洞承载能力锚杆长度、锚杆数量、锚杆预应力、侧压力系数以及塑性区范围的变化规律。基于平面弹性复变函数的方法,得到围岩任意一点的应力分量表达式,结合摩尔-库伦(Mohr-Coulomb,MC)准则,分别得到剪判据和拉判据下的拱部承载力,讨论开挖半径以及锚杆各参数对于承载力的影响,分析不同参数对孔边应力的影响,孔边应力对形状参数更敏感,会直接影响承载力。利用3DEC软件验证了理论模型的正确性。

关键词：隧道工程椭圆形隧洞复变理论承载力分析预应力锚杆

Quantum Chemistry Study on Local Structure and Properties of Amorphous Fe80P20 Alloy

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Chinese Journal of Chemical Physics 2006年第1期19卷 59-64页

作者： Zhi-gang Fang Hong-zhi Hu Jing-xue Guo qiu-ju Li School of Chemical Engineering Anshan University ot： Science and Technology Anshan 114044 China

According to the structure features of Fe80P20, A series of clusters Fe4P were designed and focused on studying the stability of local structure, charge distribution and chemical bond, Using the DFT method, energy and structure of Fe4P clusters were optimized and analyzed. The computational results showed that the energy of cluster 1（2） has the lowest energy, and the possibility of its existence in the Fe80P20 is high. Analyzing the transition states among the clusters, it was found that the clusters in the doublet state are more stable than those in the quartet state. The numbers of the Fe-P bond in the clusters play important roles in the cluster stability and electrons transfer properties, The more numbers of Fe-P bonds in the clusters, the higher the cluster stability, and the weaker the ability of P atom to get electron, The number of Fe atoms, which has bonding interactions with the P atom, is direct proportional to the average 3d orbit population of Fe atom. Basing on the orbital population, average magnetic moments of each Fe atom in the Fe4P clusters were calculated, and they are all smaller than that of single metal Fe atom. This suggests that all Fe4P clusters have soft magnetic property and they are expected to be perfect material for preparing soft magnetic apparatus.

关键词： Amorphous Fe80P20 alloy Local structure DFT Cluster

Effect of Al content on the reaction between Fe-10Mn-xAl(x=0.035wt%,0.5wt%,1wt%,and 2wt%)steel and CaO-SiO_(2)-Al_(2)O_(3)-MgO slag

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International Journal of Minerals,Metallurgy and Materials 2022年第2期29卷 256-262页

作者： Huixiang Yu Dexin Yang Jiaming Zhang Guangyuan qiu Ni Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

The effect of Al content(0.035 wt%,0.5 wt%,1 wt%,and 2 wt%)on the composition change of steel and slag as well as inclusion transformation of high manganese steel after it has equilibrated with Ca O-Si O_(2)-Al_(2)O_(3)-Mg O slag was studied using the method of slag/steel *** experimental results showed that as the initial content of Al increased from 0.035 wt%to 2 wt%,Al gradually replaced Mn to react with Si O_(2)in slag to avoid the loss of Mn due to the reaction;this process caused both Al_(2)O_(3)in slag and Si in steel to increase while Si O_(2)and Mn O in slag to *** addition,the type of inclusions also evolved as the initial Al content *** evolution route of inclusions was Mn O→Mn O-Al_(2)O_(3)-Mg O→Mg O→Mn O-Ca O-Al_(2)O_(3)-Mg O and Mn O-Ca O-Mg *** shape of inclusions evolved from spherical to irregular,became faceted,and finally transformed to *** average size of inclusions presented a trend that was increasing first and then *** transformation mechanism of inclusions was *** the initial content of Al increased,Mg and Ca were reduced from top slag into molten steel in sequence,which consequently caused the transformation of inclusions.

关键词： medium/high manganese steel Al content steel composition slag composition non-metallic inclusion slag/steel reaction

稻壳填充聚苯乙烯复合包装材料重复回收再加工过程性能研究

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包装工程 2024年第15期45卷 52-58页

作者：许霞张彦粉邱赞业李小东江太君东莞职业技术学院广东东莞523808 广东省包装印刷防伪工程技术研究中心广东东莞523817 湖南铁道职业技术学院湖南株洲412001

目的随着全球“双碳”目标的持续推进,塑料回收再利用越来越深入,研究塑料在回收过程中性能的衰减规律,对提升塑料回收效果具有重要的实践指导作用。方法采用多次反复混炼挤出加工方法对聚苯乙烯及其稻壳填充复合材料进行处理,重点研究... 详细信息

目的随着全球“双碳”目标的持续推进,塑料回收再利用越来越深入,研究塑料在回收过程中性能的衰减规律,对提升塑料回收效果具有重要的实践指导作用。方法采用多次反复混炼挤出加工方法对聚苯乙烯及其稻壳填充复合材料进行处理,重点研究热加工次数对复合材料力学性能及加工性能的影响,并对复合材料性能衰减的机理进行分析探讨。结果回收过程中重复热加工会显著降低聚苯乙烯及稻壳填充聚苯乙烯复合材料的拉伸强度、冲击强度、维卡软化温度与模塑收缩率,其中纯聚苯乙烯的性能保持率与热加工次数呈显著线性关系。经历4次热加工后聚苯乙烯的拉伸强度与冲击强度分别下降了14.35%与14.55%,复合材料的拉伸强度与冲击强度的下降幅度最大,分别达到14.55%与20.01%。稻壳的加入可以减缓热加工次数对复合材料性能衰减速率的影响,多次热加工会提升复合材料的熔融指数。结论多次重复热加工对聚苯乙烯及其稻壳填充复合材料力学性能保持率的影响较大,呈近线性关系。抗氧剂的使用可以显著降低复合材料力学性能的衰减速率,本研究可以为该类复合材料的配方与加工工艺优化提供理论指导。

关键词：稻壳聚苯乙烯成型热加工性能衰减

平均听阈正常的听神经瘤患者临床及听力学特征分析

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中国听力语言康复科学杂志 2024年第3期22卷 259-263,274页

作者：郑秋晨张秋静范佳琳吴谢东张阳兰兰王国建王秋菊韩东一解放军总医院第六医学中心耳鼻咽喉头颈外科医学部国家耳鼻咽喉疾病临床医学研究中心北京100853

目的分析平均听阈正常(PTA≤25 dB HL)的单侧听神经瘤患者的临床特征及听力学特征,为听神经瘤早期筛查及诊断提供参考。方法选取平均听阈正常的单侧听神经瘤患者32例(32耳)作为试验组,选取与年龄、性别相匹配的平均听阈正常的耳鸣患... 详细信息

目的分析平均听阈正常(PTA≤25 dB HL)的单侧听神经瘤患者的临床特征及听力学特征,为听神经瘤早期筛查及诊断提供参考。方法选取平均听阈正常的单侧听神经瘤患者32例(32耳)作为试验组,选取与年龄、性别相匹配的平均听阈正常的耳鸣患者20例(32耳)作为对照组,试验组和对照组均在符合国家标准的隔声室行纯音测听、声导抗、听性脑干反应、畸变产物耳声发射检查,回顾性分析两组临床及听力学特征。结果单纯耳鸣、耳鸣伴反复发作且可治愈的突发性听力下降为平均听阈正常听神经瘤患者常见的首发症状,占50.00%,多见于30~40岁人群。试验组听性脑干反应异常率为75.00%(24/32),畸变产物耳声反射异常率为78.12%(25/32),患耳的同侧镫骨肌声反射和健耳的交叉声反射异常率分别为28.13%、56.25%,健耳的同侧镫骨肌声反射和患耳的交叉声反射异常率分别为6.25%、62.50%。通过对比分析试验组和对照组听力学特征,两组听性脑干反应的波Ⅲ、波Ⅴ潜伏期、波Ⅰ-波Ⅲ波间期、波Ⅰ-波Ⅴ波间期,患耳的交叉声反射和健耳的交叉声反射(0.5、1、2、4 kHz)、患耳的同侧声反射(2 kHz),均存在统计学差异(P0.05)。结论听性脑干反应及镫骨肌声反射检测有助于听神经瘤早期诊断,DPOAE是敏感性高但特异性差的检测指标。对门诊平均听阈正常的单侧耳鸣,或伴有反复发作的、可治愈的突发性听力下降患者,建议联合应用听性脑干反应、镫骨肌声反射、畸变产物耳声发射综合评估,为听神经瘤的早期诊断提供依据。

关键词：听神经瘤纯音听阈正常听性脑干反应镫骨肌声反射

Effect of Zn Addition on the Microstructure and Mechanical Properties of Cast Mg-10Gd-3.5Er-xZn-0.5Zr Alloys

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Acta Metallurgica Sinica(English Letters) 2020年第11期33卷 1505-1517页

作者： qiu Zhang Wencai Liu Guohua Wu Liang Zhang Wenjiang Ding National Engineering Research Center of Light Alloy Net Forming and Key State Laboratory of Metal Matrix Composites School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China

In this work,the effects of Zn content(0-2 wt%)on microstructural evolution and mechanical properties of cast Mg-10Gd-3.5Er-0.5Zr alloys are *** results show that the as-cast Mg-10Gd-3.5Er-xZn-0.5Zr alloys are mainly composed of Mg matrix and secondary(Mg,Zn)3(Gd,Er)phases distributed along grain *** the increase in Zn content,the volume fraction of secondary(Mg,Zn)3(Gd,Er)phases increases and the grains get *** the process of solid solution treatment,Zn addition can lead to the formation of long-period stacking ordered(LPSO)structures and the volume fraction of LPSO structures increases with Zn *** addition,the Zn addition can reduce the vacancy formation energy and accelerate the diffusion rate of RE elements in Mg *** of the comprehensive effect of secondary phases and the accelerated diffusion rate,the base alloy and 2Zn alloy have less grain growth after solid solution treatment than that of the 0.5Zn alloy and 1 Zn *** precipitation process is also accelerated by enhanced diffusion *** room temperature(RT),the strengthening effect of β’+β1 precipitates is more effective than that of LPSO structures,so the peak-aged 0.5Zn alloy exhibits the most excellent mechanical performance at RT,with yield strength of 219 MPa,ultimate tensile strength 296 MPa and elongation of 6.4%.While LPSO structures have stronger strengthening effect at elevated temperature than that of β’+β1 precipitates,so the 1Zn alloy and 2Zn alloy have more stable mechanical performance than that of the base alloy and 0.5Zn alloy with the increase in tensile temperature.

关键词： Mg alloy Mg-Gd-Er-Zn Microstructure Mechanical properties Strengthening mechanism

Poisson's ratios and S-wave velocities of the Xishancun landslide,Sichuan,China,inferred from high-frequency receiver functions of local earthquakes

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Science China Earth Sciences 2021年第7期64卷 1195-1206页

作者： Zigen WEI Risheng CHU Zhiwei LI Minhan SHENG qiu ZENG Slate Key Laboratory of Geodesy and Earth's Dynamics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430077China Science and Technology on Reliability and Environmental Engineering Laboratory Beijing Institute of Spacecraft Environment EngineeringBeijing 100094China

Landslides are recurrent geological phenomena on Earth that cause heavy casualties and property losses *** this study,we use the V_(p)-k stacking and nonlinear waveform inversion methods of high-frequency receiver functions extracted from local earthquakes,to sequentially invert Poisson’s ratios and S-wave velocities of the Quaternary Xishancun landslide,which is composed of three segments,i.e.,h1,h2,and h3 from bottom to *** results show that Poisson’s ratio values are generally higher than 0.33 and that the S-wave velocities vary from 0.1 to 0.9 km s^(-1).High Poisson’s ratios(>0.44)are mainly distributed in the juncture regions between different segments,as well as the western edge of *** zones show significant variation in landslide thickness and are potentially hazardous *** velocities of 0.05–0.2 km s^(-1)with thicknesses of 10–30m are widely observed in the lower layer of the *** high Poisson’s ratios and low-velocity layer may be related to water-rich materials in these *** study suggests that the high-frequency receiver functions from local earthquakes can be used to delineate geotechnical structures,which is valuable for landslide stability analysis and hazard mitigation.

关键词： Xishancun landslide High-frequency receiver functions High Poisson's ratio Low S-wave velocity Landslide stability and hazard mitigation

2001—2020年福建省县域单元农业碳排放核算和时空演变特征分析

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水土保持通报 2024年第3期44卷 430-440,451页

作者：郑瑞姜春谢臻邱龙霞江晓忠史聪敏福建农林大学公共管理与法学院福建福州350002 自然资源部东南生态脆弱区监测修复工程技术创新中心福建福州350001

[目的]分析福建省县域尺度农业净碳排放量时空特征,为福建省及其他各省市区制定碳减排对策提供参考依据。[方法]基于种植业和畜牧业的12种碳源构建农业碳排放核算清单,采用碳排放因子法测算出农业碳排放总量;结合福建省农业特征选取7种... 详细信息

[目的]分析福建省县域尺度农业净碳排放量时空特征,为福建省及其他各省市区制定碳减排对策提供参考依据。[方法]基于种植业和畜牧业的12种碳源构建农业碳排放核算清单,采用碳排放因子法测算出农业碳排放总量;结合福建省农业特征选取7种主要农作物计算碳吸收量;并利用探索性空间分析方法分析了2001—2020年福建省农业净碳排放的时空演变特征。[结果](1)研究期内净碳排放量呈现出先上升后下降的倒“V”型变化趋势。碳源方面,农地利用碳排放占据较大比例;碳汇方面,水稻、蔬菜和甘蔗对碳吸收的贡献较大。大部分县(市)农业碳排放强度呈下降趋势,但年均下降幅度较小。(2)福建省县域碳排放量存在显著的全局空间正相关,呈现出空间集聚特征,聚集态势以高高集聚和低低集聚为主。农业碳排放强度空间分布格局变化较大,整体呈现下降趋势,其中约有一半的县(市)处于较低强度区。(3)2001—2020年福建省各县(市)的空间等级分布格局有一定程度的变动,中等排放区和中低排放区数量增多,高等排放区、中高排放区和低排放区数量减少,两极分化情况有所缓解。[结论]2001—2020年福建省大部分县域农业碳排放量和碳排放强度都呈下降趋势,碳减排取得了一定成效,但下降幅度不够大,未来还应从政策激励、产业结构优化等方面采取措施强化减排效果,促进农业低碳转型。

关键词：农业碳排放碳汇县域单元探索性空间分析福建省

考虑动态时变载荷的滚动轴承可靠性寿命评估方法

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工程设计学报 2024年第4期31卷 420-427页

作者：李军星高锐邱明李燕科刘静涛刘志卫河南科技大学机电工程学院河南洛阳471003 机械装备先进制造河南省协同创新中心河南洛阳471003 高端轴承河南省协同创新中心河南洛阳471003

载荷是滚动轴承运转过程中不可忽视的因素,不同特征的载荷会对轴承的可靠性产生差异影响。针对滚动轴承实际当量动载荷具有随机时变的特点,提出了一种考虑动态时变载荷的滚动轴承可靠性寿命评估方法,以解决传统方法忽略轴承载荷时变性... 详细信息

载荷是滚动轴承运转过程中不可忽视的因素,不同特征的载荷会对轴承的可靠性产生差异影响。针对滚动轴承实际当量动载荷具有随机时变的特点,提出了一种考虑动态时变载荷的滚动轴承可靠性寿命评估方法,以解决传统方法忽略轴承载荷时变性导致的评估精度较低的问题。利用灰色预测模型,构建了轴承当量动载荷随机时变过程的分析模型,对小样本载荷数据进行预测补充;在此基础之上,提出了基于动态应力—强度干涉模型的轴承可靠性寿命评估方法,得到了动载荷的工作区间,从而获得轴承可靠性寿命区间;进行了圆柱滚子轴承NU206E的可靠性寿命测试,对该方法进行验证。结果表明:与传统方法相比,采用所提出的方法得到的轴承寿命评估值与测试值较接近,精度较高,评估时间较短,且能获得覆盖大部分测试值的寿命区间。结合灰色预测模型和动态应力—强度干涉模型的滚动轴承可靠性寿命评估方法具有良好的工程应用价值,为变载工况下的滚动轴承可靠性评估提供了新的思路。

关键词：滚动轴承可靠性评估灰色预测模型时变应力应力—强度干涉模型