The phenomenological equations of motion for the international roughness index (IRI) have been reviewed and discussed in terms of Lagrangian method in physics. The current paper proposes a practical, two-dimensional m...The phenomenological equations of motion for the international roughness index (IRI) have been reviewed and discussed in terms of Lagrangian method in physics. The current paper proposes a practical, two-dimensional model for studying essentially three-dimensional, vibrating,?and?mechanical systems (vehicles). The purpose is to provide a new profiling method for IRI, which is practical in computations and compatible with traditional profiling for roughness of a road-surface. The modern technology employs elaborated sensors such as gyro sensor, Global Positioning System (GPS), magnetometer sensor,?and?accelerometer to measure high-speed longitudinal motions, resulting in time series of big-data expressed as compressed longitudinal spikes. The time series of longitudinal spikes obtained from high-speed longitudinal motions are traditionally considered as a background noise for constructing a profile. The conventional IRI is calculated from big-data of the road profile by employing statistical method, but the Lagrangian model dynamically determines the road profile. The useful concept and relation among the road-roughness function?, associated roughness index (ARI), acceleration and position are introduced and examined in the present paper. The associated roughness index (ARI) defined by the current dynamical approach is examined by applying virtual simulations which represent roughness of a road-surface. The current theoretical model supports and compensates information of interpreting a profile of IRI and elucidates physical meanings for the roughness index of a road-surface.展开更多
目的:比较不同底板设计金属托槽的抗剪切强度(Shear Bond Strength,SBS)及经过37℃人工唾液恒温水浴24h后对其抗剪切强度的影响。方法:选择4种不同底板设计的国产正畸金属托槽(A:传统网状底板;B:新型自锁网状底板;C:华夫样底板;D:燕尾...目的:比较不同底板设计金属托槽的抗剪切强度(Shear Bond Strength,SBS)及经过37℃人工唾液恒温水浴24h后对其抗剪切强度的影响。方法:选择4种不同底板设计的国产正畸金属托槽(A:传统网状底板;B:新型自锁网状底板;C:华夫样底板;D:燕尾状底板)。将A、B、C、D 4种托槽按是否经过37℃人工唾液恒温水浴,分为水浴组1:A1、B1、C1、D1和非水浴组2:A2、B2、C2、D2共8组,每组10个托槽。将托槽粘结于因正畸需要而拔除的上颌双尖牙上。使用I NSTRON电子万能材料试验机来检测抗剪切强度。粘结断裂的部位用粘结残留指数(Adhesi ve Remnant Index,ARI)来表示。结果:水浴组中C1、D1组的SBS均高于A1、B1,且差异具有显著性(P<0.01);非水浴组中B2、C2、D2组的SBS均显著高于A2组,且差异具有显著性差异(P≤0.001);水浴前后SBS,其中只有B、C两种托槽有差异(P<0.01),水浴组的SBS明显低于非水浴组。结论:托槽底板设计不同能够影响托槽的粘结强度,但所有的样本结果都能很好的满足正畸临床的需求。展开更多
目的:研究两种不同形状的底板(燕尾状、网状)对正畸金属托槽与瓷修复体粘接强度的影响。方法:根据瓷面处理方式及所粘接托槽的不同,将80个瓷修复体随机平均分为4组:金刚砂车针打磨+燕尾状底板托槽;金刚砂车针打磨+网状底板托槽;9.6%氢氟...目的:研究两种不同形状的底板(燕尾状、网状)对正畸金属托槽与瓷修复体粘接强度的影响。方法:根据瓷面处理方式及所粘接托槽的不同,将80个瓷修复体随机平均分为4组:金刚砂车针打磨+燕尾状底板托槽;金刚砂车针打磨+网状底板托槽;9.6%氢氟酸(hydrofl uori c aci d,HF)酸蚀+燕尾状底板托槽;9.6%HF酸蚀+网状底板托槽。将粘接后的每组瓷修复体随机平均分为2组:组1用37℃人工唾液水浴24h;组2不予处理。用硅烷偶联剂、杜拉菲勒光固化复合树脂充填材料进行粘接。检测抗剪切强度及粘结剂残留指数。结果:经人工唾液水浴后,抗剪切强度燕尾状底板托槽组较网状底板托槽组高,且差别有统计学意义(P<0.05);瓷面经打磨处理后,粘结剂残留指数网状底板组高于燕尾状底板组,且差别有统计学意义(P<0.05)。结论:燕尾状底板较网状底板提供更大的抗剪切强度;瓷面经金刚砂车针打磨较用HF酸蚀提供更大的抗剪切强度,且遗留较多粘接剂。展开更多
文摘The phenomenological equations of motion for the international roughness index (IRI) have been reviewed and discussed in terms of Lagrangian method in physics. The current paper proposes a practical, two-dimensional model for studying essentially three-dimensional, vibrating,?and?mechanical systems (vehicles). The purpose is to provide a new profiling method for IRI, which is practical in computations and compatible with traditional profiling for roughness of a road-surface. The modern technology employs elaborated sensors such as gyro sensor, Global Positioning System (GPS), magnetometer sensor,?and?accelerometer to measure high-speed longitudinal motions, resulting in time series of big-data expressed as compressed longitudinal spikes. The time series of longitudinal spikes obtained from high-speed longitudinal motions are traditionally considered as a background noise for constructing a profile. The conventional IRI is calculated from big-data of the road profile by employing statistical method, but the Lagrangian model dynamically determines the road profile. The useful concept and relation among the road-roughness function?, associated roughness index (ARI), acceleration and position are introduced and examined in the present paper. The associated roughness index (ARI) defined by the current dynamical approach is examined by applying virtual simulations which represent roughness of a road-surface. The current theoretical model supports and compensates information of interpreting a profile of IRI and elucidates physical meanings for the roughness index of a road-surface.
文摘目的:比较不同底板设计金属托槽的抗剪切强度(Shear Bond Strength,SBS)及经过37℃人工唾液恒温水浴24h后对其抗剪切强度的影响。方法:选择4种不同底板设计的国产正畸金属托槽(A:传统网状底板;B:新型自锁网状底板;C:华夫样底板;D:燕尾状底板)。将A、B、C、D 4种托槽按是否经过37℃人工唾液恒温水浴,分为水浴组1:A1、B1、C1、D1和非水浴组2:A2、B2、C2、D2共8组,每组10个托槽。将托槽粘结于因正畸需要而拔除的上颌双尖牙上。使用I NSTRON电子万能材料试验机来检测抗剪切强度。粘结断裂的部位用粘结残留指数(Adhesi ve Remnant Index,ARI)来表示。结果:水浴组中C1、D1组的SBS均高于A1、B1,且差异具有显著性(P<0.01);非水浴组中B2、C2、D2组的SBS均显著高于A2组,且差异具有显著性差异(P≤0.001);水浴前后SBS,其中只有B、C两种托槽有差异(P<0.01),水浴组的SBS明显低于非水浴组。结论:托槽底板设计不同能够影响托槽的粘结强度,但所有的样本结果都能很好的满足正畸临床的需求。
文摘目的:研究两种不同形状的底板(燕尾状、网状)对正畸金属托槽与瓷修复体粘接强度的影响。方法:根据瓷面处理方式及所粘接托槽的不同,将80个瓷修复体随机平均分为4组:金刚砂车针打磨+燕尾状底板托槽;金刚砂车针打磨+网状底板托槽;9.6%氢氟酸(hydrofl uori c aci d,HF)酸蚀+燕尾状底板托槽;9.6%HF酸蚀+网状底板托槽。将粘接后的每组瓷修复体随机平均分为2组:组1用37℃人工唾液水浴24h;组2不予处理。用硅烷偶联剂、杜拉菲勒光固化复合树脂充填材料进行粘接。检测抗剪切强度及粘结剂残留指数。结果:经人工唾液水浴后,抗剪切强度燕尾状底板托槽组较网状底板托槽组高,且差别有统计学意义(P<0.05);瓷面经打磨处理后,粘结剂残留指数网状底板组高于燕尾状底板组,且差别有统计学意义(P<0.05)。结论:燕尾状底板较网状底板提供更大的抗剪切强度;瓷面经金刚砂车针打磨较用HF酸蚀提供更大的抗剪切强度,且遗留较多粘接剂。
