The automobile industry has been searching for vehicles that use less energy and emit fewer pollutants, which has resulted in a high demand for fuel-efficient vehicles. Because of their higher strength-to-weight ratio...The automobile industry has been searching for vehicles that use less energy and emit fewer pollutants, which has resulted in a high demand for fuel-efficient vehicles. Because of their higher strength-to-weight ratio compared to traditional steel, using fiber-reinforcement composite materials in automobile bodies has emerged as the most effective strategy for improving fuel efficiency while maintaining safety standards. This research paper examined the utilization of fiber-reinforced composite materials in car bodies to meet the increasing consumer demand for fuel-efficient and eco-friendly vehicles. It particularly focused on a carbon-aramid fiber-reinforced composite impact beam for passenger car side door impact protection. Despite the encouraging prospects of the carbon-aramid fiber-reinforced beam, the research uncovered substantial defects in the fabrication process, resulting in diminished load-bearing capacity and energy absorption. As a result, the beam was un-successful in three-point bending tests. This was accomplished by using an I cross-section design with varying thickness because of the higher area moment of inertia. Vacuum-assisted resin transfer molding (VARTM) manufacturing process was used and the finished beam underwent to three-point bending tests.展开更多
目的:探讨颈后路术后早期(术后3个月)发生神经功能恶化患者长期随访的预后情况及相关危险因素。方法:回顾性分析17例在2006年1月~2012年12月间在我科接受保留一侧肌肉韧带复合体的颈后路椎管扩大成形术后早期神经功能恶化(术后3个月随访...目的:探讨颈后路术后早期(术后3个月)发生神经功能恶化患者长期随访的预后情况及相关危险因素。方法:回顾性分析17例在2006年1月~2012年12月间在我科接受保留一侧肌肉韧带复合体的颈后路椎管扩大成形术后早期神经功能恶化(术后3个月随访时mJOA评分较术前下降≥1分)的患者,以术后10年随访时m JOA评分是否恢复至术前水平将患者分为未恢复组(n=5)及恢复组(n=12),收集两组患者的基线信息、围术期资料及术后3个月、1年和10年时的改良日本骨科协会(modified Japanese Orthopaedic Association,mJOA)评分、颈椎功能障碍指数(neck disability index,NDI)、视觉模拟量表(visual analog scale,VAS)评分和影像学数据[包括Cobb角、颈椎活动度(range of motion,ROM)以及C2-C7矢状面轴向距离(sagittal vertical axis,SVA)]。比较两组患者历次随访时上述指标的差异并进行回归分析,并比较发生早期神经功能恶化时两组患者mJOA评分不同项目是否存在差异。结果:未恢复组患者合并颈椎后纵韧带骨化(ossification of longitudinal ligament,OPLL)比例明显高于恢复组,两组间在年龄、性别、体重指数、合并症、合并脊髓T2高信号、合并发育性颈椎管狭窄等基线信息以及围术期手术时间、出血量、住院时间等均无统计学差异(P>0.05)。未恢复组中1例患者发生脑脊液漏及C5神经根麻痹,恢复组中1例患者发生脑脊液漏,两组间差异无统计学意义。在术后3个月发生早期神经功能恶化后,所有患者完善影像学检查后未见减压不充分,均未行二期手术治疗。未恢复组与恢复组患者术前mJOA评分分别为13.30±2.46分及14.71±1.41分,差异无统计学意义。在发生早期神经功能恶化后,恢复组患者术后1年随访mJOA评分较术后3个月随访明显改善且与术前水平无显著性差异,术后10年随访时显著性高于术前及历次随访;未恢复组患者术后1年和10年随访时mJOA评分与术后3个月发生神经功能早期恶化时无统计学差异。两组间VAS评分及NDI评分在术前及历次随访无统计学差异;两组组内术前及历次随访时的VAS评分及NDI亦无统计学差异。恢复组历次随访时Cobb角较术前均有所增加,术后10年随访时SVA较术前增加明显;未恢复组历次随访时Cobb角及SVA与术前相比差异均无统计学意义。恢复组ROM在术后历次随访中均较术前显著性减小,未恢复组术后较术前无统计学差异。两组间术前及历次随访时Cobb角、ROM及SVA均无显著性差异。未恢复组患者发生早期神经功能恶化时更易累及下肢运动功能。对两组患者进行Logistic回归分析显示术前合并OPLL是发生术后早期神经功能恶化且术后10年难以恢复的危险因素。结论:术前合并OPLL的患者术后发生早期神经功能恶化后长期随访期更难以恢复。展开更多
矢量软件在绘制产品及工程视图时会出现数据不够准确,参数化控制偏弱等情况,另一方面专业的CAD制图软件又让普通设计师难以下手。基于Adobe Illustrator平台上的Hot Door CADtools插件在这些的问题中找到了平衡点,它能既能够像专业的CA...矢量软件在绘制产品及工程视图时会出现数据不够准确,参数化控制偏弱等情况,另一方面专业的CAD制图软件又让普通设计师难以下手。基于Adobe Illustrator平台上的Hot Door CADtools插件在这些的问题中找到了平衡点,它能既能够像专业的CAD软件一样为图形标注提供准确的尺寸,同时又让CAD制图变得亲切和富有人性化。展开更多
文摘The automobile industry has been searching for vehicles that use less energy and emit fewer pollutants, which has resulted in a high demand for fuel-efficient vehicles. Because of their higher strength-to-weight ratio compared to traditional steel, using fiber-reinforcement composite materials in automobile bodies has emerged as the most effective strategy for improving fuel efficiency while maintaining safety standards. This research paper examined the utilization of fiber-reinforced composite materials in car bodies to meet the increasing consumer demand for fuel-efficient and eco-friendly vehicles. It particularly focused on a carbon-aramid fiber-reinforced composite impact beam for passenger car side door impact protection. Despite the encouraging prospects of the carbon-aramid fiber-reinforced beam, the research uncovered substantial defects in the fabrication process, resulting in diminished load-bearing capacity and energy absorption. As a result, the beam was un-successful in three-point bending tests. This was accomplished by using an I cross-section design with varying thickness because of the higher area moment of inertia. Vacuum-assisted resin transfer molding (VARTM) manufacturing process was used and the finished beam underwent to three-point bending tests.
文摘目的:探讨颈后路术后早期(术后3个月)发生神经功能恶化患者长期随访的预后情况及相关危险因素。方法:回顾性分析17例在2006年1月~2012年12月间在我科接受保留一侧肌肉韧带复合体的颈后路椎管扩大成形术后早期神经功能恶化(术后3个月随访时mJOA评分较术前下降≥1分)的患者,以术后10年随访时m JOA评分是否恢复至术前水平将患者分为未恢复组(n=5)及恢复组(n=12),收集两组患者的基线信息、围术期资料及术后3个月、1年和10年时的改良日本骨科协会(modified Japanese Orthopaedic Association,mJOA)评分、颈椎功能障碍指数(neck disability index,NDI)、视觉模拟量表(visual analog scale,VAS)评分和影像学数据[包括Cobb角、颈椎活动度(range of motion,ROM)以及C2-C7矢状面轴向距离(sagittal vertical axis,SVA)]。比较两组患者历次随访时上述指标的差异并进行回归分析,并比较发生早期神经功能恶化时两组患者mJOA评分不同项目是否存在差异。结果:未恢复组患者合并颈椎后纵韧带骨化(ossification of longitudinal ligament,OPLL)比例明显高于恢复组,两组间在年龄、性别、体重指数、合并症、合并脊髓T2高信号、合并发育性颈椎管狭窄等基线信息以及围术期手术时间、出血量、住院时间等均无统计学差异(P>0.05)。未恢复组中1例患者发生脑脊液漏及C5神经根麻痹,恢复组中1例患者发生脑脊液漏,两组间差异无统计学意义。在术后3个月发生早期神经功能恶化后,所有患者完善影像学检查后未见减压不充分,均未行二期手术治疗。未恢复组与恢复组患者术前mJOA评分分别为13.30±2.46分及14.71±1.41分,差异无统计学意义。在发生早期神经功能恶化后,恢复组患者术后1年随访mJOA评分较术后3个月随访明显改善且与术前水平无显著性差异,术后10年随访时显著性高于术前及历次随访;未恢复组患者术后1年和10年随访时mJOA评分与术后3个月发生神经功能早期恶化时无统计学差异。两组间VAS评分及NDI评分在术前及历次随访无统计学差异;两组组内术前及历次随访时的VAS评分及NDI亦无统计学差异。恢复组历次随访时Cobb角较术前均有所增加,术后10年随访时SVA较术前增加明显;未恢复组历次随访时Cobb角及SVA与术前相比差异均无统计学意义。恢复组ROM在术后历次随访中均较术前显著性减小,未恢复组术后较术前无统计学差异。两组间术前及历次随访时Cobb角、ROM及SVA均无显著性差异。未恢复组患者发生早期神经功能恶化时更易累及下肢运动功能。对两组患者进行Logistic回归分析显示术前合并OPLL是发生术后早期神经功能恶化且术后10年难以恢复的危险因素。结论:术前合并OPLL的患者术后发生早期神经功能恶化后长期随访期更难以恢复。
文摘矢量软件在绘制产品及工程视图时会出现数据不够准确,参数化控制偏弱等情况,另一方面专业的CAD制图软件又让普通设计师难以下手。基于Adobe Illustrator平台上的Hot Door CADtools插件在这些的问题中找到了平衡点,它能既能够像专业的CAD软件一样为图形标注提供准确的尺寸,同时又让CAD制图变得亲切和富有人性化。
