Abstract Aiming at the problem that TC4 titanium alloy panel parts after welding have large internal residual stress and obvious panel deformation, which can’t meet the requirements of the parts, the ...viscoelastic plastic model of titanium alloy panel parts is established by finite element analysis, and the welding deformation-thermal alignment collaborative simulation environment is established by ANSYS, and the welding deformation and thermal alignment process are analyzed by numerical simulation. The law of shape correction when the correction temperature is 600 °C, 650 °C, 700 °C and the holding time is 3600s, 5400s and 7200s, respectively, and the calculation formula of springback rate is established to evaluate the effect of thermal shape correction, so as to optimize the heat treatment correction process. The results show that the correction temperature and holding time have obvious influence on the correction effect. When the correction temperature is 700 °C and holding time is 7200s, the correction effect is the best, and the springback rate is controlled below 25%, which meets the requirements of machining accuracy.
Abstract
In order to solve the problem that the material utilization rate of soluble magnesium base alloy rod is less than 30%, the method of magnesium alloy rod casting is adopted to improve the ...material utilization rate. However, the cooling mode affects the dissolution rate of soluble magnesium alloy after casting. According to the different thermal conductivity of different materials, cylindrical graphite molds and copper molds with diameters of 5mm and 40mm are selected for casting magnesium alloys. In order to ensure the reliability of experimental results, polarization method and weight loss method were used to analyze the dissolution rate of soluble magnesium base alloy under different cooling modes. The test results show that: Magnesium alloy is cooled and solidified by copper mold with a diameter of 5mm, and the dissolution rate is the highest in 1.5% NaCl solution with a speed of 1.2856mm/h. The grain size of magnesium alloy can be refined by increasing cooling rate. After the grain boundary of magnesium-based alloy is refined, the grain boundary between the alloy increases, the number of corrosion galvanic cells increases, and the dissolution rate of magnesium-based alloy gradually increases.
Peri-menopausal women may experience a range of symptoms which affect quality of life and for which there may be no treatment. The aim of the study was to evaluate whether a mindfulness-based stress ...reduction (MBSR) intervention delivered to peri-menopausal women could alleviate preclinical symptoms of depressive moods.
Patients presenting in a gynaecology department were screened for peri-menopausal symptoms. Women with preclinical anxiety, depression and/or sleep disturbance who met the inclusion criteria were invited to participate in the study. Group training was held twice a week for eight weeks; self-practice was assigned and reported. Symptoms were assessed at baseline and upon completion. Participants’ reports on self-practice were collected besides the 16 -h class contact.
Of all 128 enrolled women, 7 (5.5 %) did not complete the program and were excluded. Baseline scores (N = 121) were 63.42 ± 5.54 (mean ± SD) for anxiety; 68.31 ± 4.72 for depression; and 18.37 ± 2.24 for sleep disturbance. Upon completion of the program, symptoms were improved, and symptom scores lower (p < 0.01): 48.26 ± 6.47 for anxiety, 50.27 ± 6.54 for depression, and 10.64 ± 4.38 for sleep disturbance. Besides group training, 59 participants (48.8 %) did self-practice at least 3 times/week; 39 participants (32.2 %) did 1–2 times/week; and 23 participants (19.0 %) did none. Frequency of self-practice was associated with magnitude of symptom relief (p < 0.01).
MBSR may be a useful self-care tool for peri-menopausal women experiencing depressive moods. Clinical trials and follow-up studies are needed to understand the pattern of incorporating MBSR in self-management, and any long-term health effects.
