推拿法常见错误动作的动力学分析

目的 :分析推拿法常见错误动作的动力学特征。方法 :利用中医推拿手法测力分析仪 ,采集、分析法常见错误动作的三维压力曲线及合力作用点轨迹形态等参数。结果 :发现旋转、跳动、敲打、拖动、粘动等法常见错误动作的三维压力曲线及R值与正确法相比有明显差别。提示 :法的错误动作存在客观的动力学特征。     

翻身锻炼法为主治疗腰椎压缩性骨折50例

１９９７年起笔者采用翻身锻炼法为主治疗腰椎压缩性骨折５０例效果满意,报道如下。１　临床资料本组５０例中男３７例,女１３例;年龄最大者６９岁,最小者２８岁,平均４８－５岁,其中５０岁以上者１５例,占３２％．Ｌ１骨折２５例,Ｌ２骨折２０例,Ｌ３骨折４例,Ｌ１合并Ｌ２骨折１例。合并脑外伤５例,股骨骨折３例,科雷斯骨折５例,肋骨骨折并血气胸者３例。２　治疗方法单纯椎体压缩、无椎体脱位者入院后睡硬板床,腰部垫棉垫,外敷本院自制的活血消痛膏,内服行气、活血、止痛等中药,日１剂。翻身锻炼法：术者站立在患者病…     

一种从胸HRCT图像序列分割肺的自动化方法

提出了一种从胸部高分辨率CT图像序列中由粗到细分割肺组织的自动化方法.首先基于结构连续性的分割策略,采用阈值法和数学形态学分割出粗略的肺实质,再用区域生长法去掉气管,最后通过滚球法弥合肺边缘的裂缝及缺口.对6个数据集(共1720层图像)的分割结果成功率均在90%以上,每层分割时间小于6s,相似度分析表明自动与手工分割结果吻合良好,并能较好地保留细节.     

Discrimination of Surface Topographies Created by Two-Stage Process by Means of Multiscale Analysis

The fundamental issue in surface metrology is to provide methods that can allow the establishment of correlations between measured topographies and performance or processes, or that can discriminate confidently topographies that are processed or performed differently. This article presents a set of topographies from two-staged processed steel rings, measured with a 3D contact profilometer. Data were captured individually from four different regions, namely the top, bottom, inner, and outer surfaces. The rings were manufactured by drop forging and hot rolling. Final surface texture was achieved by mass finishing with spherical ceramic media or cut wire. In this study, we compared four different multiscale methods: sliding bandpass filtering, three geometric length- and area-scale analyses, and the multiscale curvature tensor approach. In the first method, ISO standard parameters were evaluated as a function of the central wavelength and bandwidth for measured textures. In the second and third method, complexity and relative length and area were utilized. In the last, multiscale curvature tensor statistics were calculated for a range of scales from the original sampling interval to its forty-five times multiplication. These characterization parameters were then utilized to determine how confident we can discriminate (through F-test) topographies between regions of the same specimen and between topographies resulting from processing with various technological parameters. Characterization methods that focus on the geometrical properties of topographic features allowed for discrimination at the finest scales only. Bandpass filtration and basic height parameters Sa and Sq proved to confidently discriminate against all factors at all three considered bandwidths.     

Cold Rolling Texture Prediction Using Finite Element Simulation with Zooming Analysis

Cold rolling is widely employed in the manufacturing industry for the production of metal plates. In the cold rolling process, the thickness reduction of the metal plate under the recrystallization temperature generates severe anisotropy; this influences the subsequent forming processes. Therefore, the generation and prediction of metal plate anisotropy during cold rolling is a highly interesting research topic involving upstream studies of sheet metal forming. In this study, using the finite element method with zooming analysis, we established an efficient elastic–plastic analysis method to predict the metal plate texture after cold rolling. This method for cold rolling texture prediction was confirmed by comparing the experimental and simulation results of cold rolling for an S45C plate with a body-centered cubic lattice. Further, the numerical analysis method proposed in this study can contribute to the study of anisotropy as an alternative to experimental approaches.     

A Comparative Analysis of the Physical Modelling of Two Methods of Balls Separation

The article presents the results of model tests with which a comparative analysis of two methods of ball separation during the skew rolling process was carried out. A verification of the results obtained in the physical modelling process with the results obtained in the real process of skew ball rolling was also carried out. During the physical modelling, the effect of changing the ball separation method on the quality of the products obtained, variations in maximum torque values and maximum radial forces were analyzed. In the case of real tests, the results were verified with the results of physical modelling, in which the surface quality and torque values for one of the tool sets were compared. Physical modelling was used to verify the differences between the two methods of ball separation. Commercial plasticine based on synthetic wax from the manufacturer PRIMO was used as a model material for physical analysis. The plasticine used for testing was cooled to 0 °C and the cooling process took 24 h. The tools used for the physical modelling were 3D printed and the material used was ABS. The method of physical modelling using plasticine as a model material allows for a correct analysis of hot metal forming processes.     

Microstructure Evolution of Graphene and the Corresponding Effect on the Mechanical/Electrical Properties of Graphene/Cu Composite during Rolling Treatment

Rolling enables the directional alignment of the reinforcements in graphene/Cu composites while achieving uniform graphene dispersion and matrix grain refinement. This is expected to achieve a breakthrough in composite performance. In this paper, the process parameters of rolling are investigated, and the defects, thickness variations of graphene and property changes of the composite under different parameters are analyzed. High-temperature rolling is beneficial to avoid the damage of graphene during rolling, and the prepared composites have higher electrical conductivity. The properties of graphene were investigated. Low-temperature rolling is more favorable to the thinning and dispersion of graphene; meanwhile, the relative density of the composites is higher in the low-temperature rolling process. With the increase of rolling deformation, the graphene defects slightly increased and the number of layers decreased. In this paper, the defect states of graphene and the electrical conductivity with different rolling parameters is comprehensively investigated to provide a reference for the rolling process of graphene/copper composites with different demands.     

Microstructural and Texture Evolution in Pure Niobium during Severe Plastic Deformation by Differential Speed Rolling

The evolution of the microstructure and texture in body-centered cubic (BCC) niobium (Nb) during conventional rolling and high-ratio differential rolling (HRDSR) at room temperature were compared. More effective grain refinement of the initial microstructure through continuous dynamic recrystallization (CDRX) occurred in the samples processed by HRDSR, but the overall degree of grain refinement was small, despite having undergone severe plastic deformation due to the low rate of CDRX. CDRX more preferentially proceeded on {111}<uvw> γ-fiber grains than on {001}<110> α-fiber grains. The HRDSR-processed samples exhibited weaker α-fiber and stronger γ-fiber than the conventionally processed samples, which indicates that the high shear deformation induced by HRDSR discourages the development of α-fiber while promoting the development of γ-fiber. The HRDSR processed Nb showed a high tensile strength of 450 MPa, and the major strengthening mechanism for the HRDSR-processed Nb was dislocation-density strengthening at large thickness reductions.     

Comparison of Microstructure,Texture, and Mechanical Properties of TZ61 and AZ61 Mg Alloys Processed by Differential Speed Rolling

In this work, the comparison of microstructure, texture, and mechanical properties of the newly developed TZ61 (Mg-6Sn-1Zn) alloy with the commercially available AZ61 (Mg-6Al-1Zn) has been presented. Both analyzed Mg alloys were processed by conventional symmetric and asymmetric rolling (i.e., Differential Speed Rolling—DSR). The microstructure and texture were examined by EBSD and XRD, whereas the mechanical behavior was investigated by uniaxial tensile tests. DSR processing led to more effective grain refinement of both TZ61 and AZ61 sheets. However, a high fraction of Mg₂Sn phase precipitates in the TZ61 sheets hindered grain growth what resulted in their smaller grain size as compared to AZ61 sheets. DSR processing lowered also the basal texture intensity in the TZ61 and AZ61 sheets. A unique basal poles splitting was observed for the as-rolled TZ61 alloy, while AZ61 alloy exhibited a typical single-peak basal texture. Finally, the reduced grain size and weakened basal texture by DSR processing caused increase of plasticity of the annealed TZ61 and AZ61 sheets. Nevertheless, the annealed AZ61 sheets showed higher uniform elongation and strength (as compared to TZ61 ones), which has been attributed to their significantly lower texture intensity and greater ability to strain hardening.     

Microstructural Evolution and Mechanical Properties of Pure Aluminum upon Multi-Pass Caliber Rolling

The paper presents the microstructure and mechanical property of pure aluminum (Al) fabricated by multi-pass caliber rolling at room temperature. The finite element modeling (FEM) simulation was performed to explore the changes in rolling force, effective stress and strain, and temperature under various rolling passes. As the number of rolling passes increased, the overall temperature, effective stress, and strain gradually increased, while the maximum rolling force decreased. In addition, due to the dynamic recrystallization (DRX), the average grain size reduced from 1 mm to 14 µm with the increase in rolling passes. The dislocation density increased and it gradually evolved into the high-angle grain boundaries (HAGBs). Moreover, the initial cubic texture rotated to the brass component and finally changed to a mixture of Cube and Brass types. The highest tensile yield strength (TYS), ultimate tensile strength (UTS) and elongation (El.) of caliber rolled pure Al (116 MPa, 135 MPa, and 17%, respectively) can be achieved after 13 rolling passes, which mainly attributed to grain refinement.