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关键词： Bridge network   Biquartic impedance   HMDV   Negative effects of vertical vibration  

摘要： In order to solve the vertical vibration negative effect problem caused by the increase of the unsprung mass in the hub motor driven vehicle (HMDV), a novel mechatronic suspension using the bridge electrical network is proposed. Firstly, the bridge electrical networks composed of two capacitors, two inductors, and one resistor are summarized and their impedance functions are analyzed forward through the structural method. Then a quarter HMDV model is constructed, and the optimal element parameters in the electrical networks are selected through the Pattern Search algorithm. The influence of element parameters perturbation of the optimal structure on the output response of HMDV suspension is further analyzed. Results show that the proposed bridge electrical network can be realized as a biquartic impedance. It can be equivalent to a mechanical impedance of the suspension through a linear motor. Compared with the conventional suspension, the root-mean-square values of the dynamic tire load and the suspension working space are reduced by 10.76% and 18.10%, respectively. The vibration at low and high frequencies of the unsprung mass is suppressed, effectively improving the grounding and handling stability of the vehicle.

关键词： Bi-material interface   Uniform stress   Eshelby conjecture   Half-plane   Inverse problem  

摘要： In the theory of two-dimensional linear elasticity, an elliptical inclusion is known to attain a constant stress field when perfectly buried in an infinite homogeneous matrix if a uniform eigenstrain is applied to it. The focus of this paper falls on the question: when the initially elliptical inclusion verges on a bi-material interface, what would happen to its configuration if it is required to retain the internal constant stress? Specifically, we explore the anti-plane shear version of this question (the version of plane deformations or three-dimensional deformations seems, however, insoluble at this stage), in which an inclusion undergoing a uniform (anti-plane shear) eigenstrain is embedded in a bi-material structure composed of two infinite elastic half-planes whose interface is straight and perfectly bonded, and the shape of the inclusion is to be determined such that the eigenstrain-induced stress inside the inclusion appears to be a constant. Unlike most optimization methods-driven solution procedures for finding the shape of the inclusion approximately in which huge computation is required, we derive by a rigorous theoretical analysis an exact integral equation with respect to the boundary curve of the inclusion that is sufficiently and necessarily related to the existence of a constant stress inside the inclusion. We solve this integral equation via the use of some analytic techniques and present in several illustrative examples a variety of shapes of the inclusion achieving constant stresses. We discover some interesting phenomena for the evolution of the shape of the uniformly stressed inclusion relative to the stiffness of the nearby interface. (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic). (sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(si

关键词： Discontinuous curved fiber reinforced composites (DCFRCs)   Representative volume element (RVE)   Modified RSA algorithm   Modified rule-of-mixture   Elastic properties   Fiber waviness  

摘要： The present study proposes a modified random sequential absorption (RSA) algorithm to generate a representative volume element (RVE) model for predicting the elastic properties of discontinuous curved fiber reinforced composites (DCFRCs) with varying fiber waviness functions and orientations. A small-move method was proposed to modify the traditional RSA algorithm. In comparison with the original RSA algorithm, the generation efficiency of the proposed modified RSA algorithm increased by over 40%, and the achievable maximum fiber volume fraction could reach up to 15% with a fiber aspect ratio of 15. The generated RVE model was utilized in conducting finite element analysis to investigate the effect of fiber waviness and wavy functions on the elastic properties of DCFRCs. Finally, a modified rule-of-mixture was proposed to predict the elastic properties of DCFRCs with various fiber orientations. The results indicated that the elastic properties predicted by the modified rule-of-mixture were in good agreement with those obtained from the RVE model, thereby demonstrating its effectiveness.

摘要： 由秦小强等编著,重庆大学电子音像出版社出版的《包装艺术设计》一书,介绍了包装设计的基础知识,探讨了产品包装设计的构思与方法,以及包装设计的构图与视觉流程.书中还对产品包装容器造型设计、视觉形象设计进行了详细讲解,对包装的印刷与制作流程进行了全面剖析,并对食品包装设计进行了深入探究.

摘要： 由刘军丽等编著的《美食旅游发展研究:理论与实践》一书,综合运用管理学、饮食文化学、人类学、统计学、经济学、旅游规划学等多个学科理论,对美食旅游实践问题进行了深入研究,可以为新时期美食旅游业态创新提供更加完善的学理依据和指导.

关键词： 桡骨远端骨折   夹板   3D打印   快速无网格分析   临床缺陷  

摘要： 背景:随着医疗技术的不断发展,桡骨远端骨折的治疗面临着更加精准化和个性化的需求。传统夹板固定方法在临床应用中存在一定的局限性,常出现固定不牢固、易于发生压疮等缺陷。采用快速无网格仿真技术验证改进的3D打印夹板的效能,有望为桡骨远端骨折带来更精准、更有效的治疗方案。目的:探索基于临床缺陷改进的桡骨远端骨折3D打印夹板的设计方法,并采用快速无网格分析验证其临床效能。方法:回顾性分析桡骨远端骨折夹板固定的临床缺陷,并针对性改进设计3D打印夹板,通过计算机辅助设计制图,制作出传统夹板和改进的新型3D打印夹板的数字模型。使用快速无网格分析工具进行仿真分析,计算总体、骨骼、软组织及夹板位移和应力分布情况。结果与结论:①与传统夹板相比,改进的新型3D打印夹板对皮肤的压力比较均衡,具有较好的体表贴合性,没有明显的应力集中;位移更小、移动范围更合理;②通过对临床缺陷进行分析可以设计改进桡骨远端骨折3D打印夹板,快速无网格分析结果验证了改进3D夹板的优势,可为其临床应用提供依据。

关键词： 股骨转子间骨折   股骨近端抗旋髓内钉   随访   髋关节功能   骨质疏松   危险因素   骨科植入物  

摘要： 背景:目前国内外研究主要集中在不同术式治疗股骨转子间骨折的比较及股骨近端防旋髓内钉手术失败的风险,对股骨近端防旋髓内钉术后患肢髋关节功能预后研究较少。目的:分析老年转子间骨折患者行股骨近端防旋髓内钉置入后髋关节功能恢复不良的影响因素,构建术后髋关节功能预测评分系统并探讨其价值。方法:选择2021年6月至2023年6月在徐州医科大学附属医院接受股骨近端防旋髓内钉内固定治疗的股骨转子间骨折患者150例,根据术后随访Harris髋关节功能评分分组,评分≥80分为优良组,评分<80分为不良组,采用单因素及二元回归分析探讨导致术后髋关节功能不良的危险因素,根据危险因素建立评分表。采用受试者工作曲线探讨该评分系统预测股骨近端防旋髓内钉置入术后髋关节功能的价值。结果与结论:①150例患者根据术后1年随访时患侧髋关节Harris评分标准分组,功能恢复不良组52例,恢复优良组98例,不良率为34.7%;②两组患者单因素比较结果显示:术后髋关节功能不良组与优良组在年龄、骨密度、术前基础合并症数量、外侧壁的分型、螺旋刀片位置、复位质量及术后初次下床锻炼时间方面存在显著差异(P<0.05);③二元Logistic回归分析结果显示:年龄≥75岁(OR=2.834)、骨质疏松(OR=3.002)、术前基础合并症数量>2个(OR=4.024)、外侧壁破裂(OR=2.999)、螺旋刀片位置差(OR=4.025)、术后初次下床锻炼时间>4周(OR=3.153)是转子间骨折行股骨近端防旋髓内钉置入术后髋关节功能不良的独立危险因素(P<0.05),复位质量差(OR=1.026)是非独立危险因素(P>0.05);④依据二元回归分析结果构建术后髋关节功能优良预测评分系统,经受试者工作特征曲线分析,此评分系统预测术后髋关节功能不良的界值为4.5分,曲线下面积为0.797,灵敏度为83.7%,特异性为65.4%;⑤提示年龄≥75岁、骨质疏松、术前基础合并症数量>2个、外侧壁破裂、螺旋刀片位置差、术后初次下床锻炼时间>4周是转子间骨折行股骨近端防旋髓内钉术后发生髋关节功能不良的危险因素,构建评分预测系统可以为临床早期识别术后髋关节功能不良的高风险患者提供参考价值,有利于指导临床早期干预、采用更加个性化的治疗及康复方案,促进患者术后髋关节功能恢复。

关键词： 腰椎间盘突出症   经皮椎间孔镜椎间盘切除   整体功能性体育锻炼   传统康复   腰椎生物力学  

摘要： 背景:经皮椎间孔镜椎间盘切除术患者预后较差,预后较差的原因与缺少功能锻炼有关,常规的康复方法疗效有限,主要原因是康复方法较单一且缺少针对性,因此需要改进整体功能性体育锻炼方法。目的:探讨整体功能性体育锻炼对行经皮椎间孔镜椎间盘切除的腰椎间盘突出症患者术后腰椎生物力学的影响。方法:选择2021年4月至2022年9月在河南省人民医院行经皮椎间孔镜椎间盘切除术的腰椎间盘突出症患者120例作为研究对象,根据随机数法随机分为传统康复组和整体功能性体育锻炼组,两组患者分别进行8周的传统康复和整体功能性体育锻炼。在干预前和干预8周后,使用IsoMed2000等速肌力测试系统进行等速肌力测试;应用Oswestry功能障碍指数评估腰椎功能;以目测类比评分法评价疼痛程度;以焦虑自评量表和抑郁自评量表评估焦虑和抑郁症状。在锻炼干预8周后,采用改良Macnab疗效评定标准评定疗效。结果与结论:①干预8周后,与传统康复组比较,整体功能性体育锻炼组患者的腰背肌群屈肌和伸肌峰力矩、平均功率均升高,屈伸峰力矩比降低,Oswestry功能障碍指数、目测类比评分、焦虑自评量表和抑郁自评量表评分均降低,改良Macnab疗效优良率升高(P<0.001);②提示与传统康复方案相比,腰椎间盘突出症患者经皮椎间孔镜椎间盘切除术后进行整体功能性体育锻炼可有效改善腰椎生物力学和功能、缓解疼痛、减少术后不良情绪、改善预后,具有较高的临床价值。