Abstract The cutting force and temperature have a significant impact on the service life durability of gear skiving cutters. Due to unreasonable design, existing process parameters lead dramatically nonuniform temperature, which aggravates rapid wear To address this issue, paper first establishes finite element model internal circular arc tooth in pin wheel housing, simulation is simplified improve computation efficiency. Next, single parameter analyzed by controlling variable. Then, an...

Injection-production operation parameters, the minimum injection gas pressure (IGP: pressure), IGP interval, residence time, and injection-production cycle of underground salt rock storage under long-term operation, affect not only capacity working ability a cavern but also be crucial to safety stability surrounding rock. A 3D geo-mechanical model is established study in period. The deformation, expansion factor, volume shrinkage, plastic zone are comprehensively considered for predicting...

Unbalanced body pressure distribution caused by poor sitting posture is a significant factor causing lumbar disease. Research on the dynamic adjustment strategy for comfort of great significance to prevention and improvement In this study, based sensor array, in different postures are obtained, including: back bow, waist slip, right leaning, standard position, left leaning. The recognition human was achieved using support vector machine algorithm accuracy rate reach 83.33%. Furthermore,...

Abstract Variations in immune cell counts can trigger depressive symptoms, while physical activity effectively reduces the risk and severity of symptoms. This study, based on NHANES database, analyzes relationship between neutrophil count symptoms explores moderating effect this relationship. Cross-sectional data from database were extracted, including counts, PHQ-9 scores for self-assessment Global Physical Activity Questionnaire (GPAQ) (PA). The interrelations among activity, count,...

In the process of screw thread manufacturing, cooling liquid or lubricating oil will adhere to surface, which affects vision measurement results parameters. To simulate adhesion behavior on surface during actual measurement, four different attachment states were set in this experiment. An image measuring instrument was used collect images states. Then, distribution film analyzed with computer processing. The visual inspection method obtain relative influence rate result Finally, an...

Purpose The purpose of this paper is to obtain the single-tooth stiffness, time-varying meshing stiffness and comprehensive internal external face gears analyze influence modulus, pressure angle tooth width each gear on in nutation transmission. Design/methodology/approach From point view material mechanics, teeth are simplified as spacial variable cross-section beams. shear deformation teeth, bending root additional elastic caused by base gotten trapezoidal section method, thus can be...

Tool design is one of the key factors that restrict development gear skiving technology since principle does not correspond to cutting principle. The existing tool cannot achieve ideal machining accuracy and reasonable angles. In view this, some research has been done in this paper. Firstly, investigated essentially according motions. Then, analyzed based on theory conjugate surface, a new method proposed match For all patterns for various kinds workpieces are enumerated summarized abstract...

Rack-and-pinion gear sets with variable transmission ratios have gradually become a standard core component in steering systems, as the harmony between portability and sensitivity vehicle can be achieved such applications. When conventional meshing theory is adopted to calculate point clouds of variable-ratio tooth surfaces, drawbacks will occur respect unevenness cloud density, inaccessible surface boundaries, fusion at interface working fillet. Thus, generated ratio surfaces inapplicable...

Abstract Objective: To analyze the relationship between neutrophil count and depression based on NHANES database to explore moderating effect of physical activity neutrophils depression. Methods: Cross-sectional data from were extracted, including demographic information, count, scores PHQ-9 self-assessment scale, GPAQ (Global Physical Activity Questionnaire). Pearson correlation, binary logistic regression, restricted cubic spline models, linear regression equation models used association...

为了改善和优化眼镜镜片的加工流程,避免镜片尖边加工过程中刀轴矢量变化剧烈、影响工件表面的加工质量,提出了一种基于UG NX的五轴数控加工路径。利用智能镜框扫描仪对镜框边缘进行扫描,获得镜框凹槽点云数据文件,编写相应程序对符合眼镜片加工标准的OMA文件中的球坐标数据进行坐标及格式转换等处理。基于NURBS曲线拟合算法,实现刀路轨迹的连续性并保证拟合曲线的精度。设计和建立一种控制刀轴矢量平滑变化的刀轴驱动约束方法,依靠曲线驱动刀轴及镜片曲面法向量约束刀轴使刀头平滑进给,并将刀轨文件经过后处理转换为NC文件。最后,对加工后的镜片进行误差测量,结果表明,通过点云数据拟合刀路曲线的方法提高了加工面的精确度和光滑性,有效缩减了加工流程,提高了加工效率。

With the speeding up of industrialisation process, lightweight products are more and favoured by people, so engineering plastic is born at right moment. Engineering plastics often used for structural materials in engineering. They have high mechanical strength, such as temperature resistance, wear-resisting. development plastics, their advantages been gradually accepted people. In recent years, statistics shows that about 35% to produce auto spare parts. Using instead tempered a trend energy...

<title>Abstract</title> In order to find out the main causes of coal mine safety accidents and improve pertinence risk management control, identification analysis risks hidden dangers are carried based on accident reports. And combing complex network theory A model for evolution is constructed. The key elements that affect obtained through quantitative research characteristic indicators risks. nodes spread interference overall efficiency. results show illustrate characteristics a small-world...

Abstract This paper designs a multifunctional mobility aid based on the STM32 microcontroller, which mainly provides security for daily life of elderly. The analyzes basic working principle aid, and mechanized structure; thereby realizing mechanization, intelligence multi-functional technical characteristics can effectively avoid troubles caused by leg failure in function elderly, provide convenience elderly to go out.

摘要: 羞怯与社会认知密切相关, 而面孔识别是人们社会生活中的一项重要的社会认知功能。目前关于羞怯的电生理学研究大多关注表情的效价效应和面孔的新旧效应对羞怯个体面孔加工的影响, 却忽视了羞怯个体在基本的面孔识别能力—— 面孔-物体识别中可能存在的认知神经差异。因此, 本研究采用ERP技术,使用GO/Nogo范式的面孔-物体识别任务, 对17名羞怯大学生和17名非羞怯大学生在面孔结构编码中的N170成分进行考察, 以期发现不同羞怯水平大学生在早期面孔加工中的认知神经差异。本研究发现, 非羞怯大学生对面孔结构具有加工优势, 识别面孔时, 非羞怯大学生的N170波幅显著大于羞怯大学生的N170波幅, 识别物体时则不存在组间差异; N170是面孔识别的特异性成分, 面孔诱发的N170波幅显著大于物体诱发的N170波幅; N170表现出大脑右半球的加工优势。

Background: Nutation drive is being extensively investigated due to its ability achieve a high reduction ratio with compact structure and the potential for low vibration, efficiency design flexibility. However, many problems including difficulty process inner bevel gear, less number of teeth in engagement not suitable high-power transmission have restricted development. Objective: The purpose this paper analyze contact strength patent about new nutation developed based on meshing between two...

The manufacturing process of key parts in RV reducer is one the technologies affecting mass production reducer. In order to improve accuracy and efficiency pre-grinding circular arc teeth pin gear housing reducer, slicing technology applied internal tooth processing for first time. Firstly, cutting principle analyzed, then motion model established. Based on kinematic slicing, geometric design edge faces cutter carried out according surface conjugation. Finally, test new out, which proves...

Characteristics of gas emission in face 40108 were analyzed. The results show that the high-position tunnel system and grouting are effective control systems, 83% rates come from gob. When monitoring points away coal about 33-38m 78-93m strike direction, gob concentrations reach to 5% 10%, respectively. relative decrease with a negative exponential function when daily outputs or advancing increase. With increased air flow rate 40108, absolute return airway increase coinstantaneous, while it...

The signals of convoluted mixtures have a stated non-stationary identity, and the change their spectrum with time-varying usually could not be observed from frequency domain, but they can by time-frequency method. Therefore, blind separation based on analysis is proposed in this paper. For space-albinism mixed matrices joint diagonalization are simulated to separate mixtures. Two kinds methods, Wigner-Ville distribution improved distribution, introduced, which calculated MATLAB 7.0 software....