Effects of positive psychological control intervention on sleep and psychology of officers and soldiers working at sea

BACKGROUND The working environment of submarine crews is also very special.They are in a closed,high-temperature,high-noise,high-vibration and narrow working and living space for a long time,and they suffer from physical discomfort caused by seasickness,which will affect the mental health of officers and soldiers.American psychologists have achieved positive results in psychological resilience training for officers and soldiers from the perspective of positive psychology.At present,there are few reports on the correlation between psychological resilience in the field of domestic research on submarine crew psychology,and it is necessary to conduct further research.METHODS A total of 121 soldiers working in a confined space of a large ship were randomly divided into an experimental group and a control group.The 50 soldiers in the experimental group were given a training course intervention,while the 71 soldiers in the control group did not receive any intervention measures.The Pittsburgh Sleep Quality Index,Psychological Resilience Scale,military Psycho-logical Stress Self-Assessment Questionnaire,and General Self-Efficacy Scale scores were compared before and 6 months after the intervention.RESULTS Under the positive psychological control intervention,except for sleep efficiency(P=0.05),the difference between the remaining dimensions of the Pittsburgh Sleep Quality Index scores and the total scores of the experimental group compared with the control group was statistically significant(P<0.05);the assessment of the psychological condition showed that,in addition to the Psychological Stress Self-assessment Questionnaire for Military Personnel scores(P=0.05),the scores of the Mental Toughness Scale(Dispositional Resilience Scale Resilience II)in the experimental group,General Self-Efficacy Scale scores were statistically significant(P<0.05)compared to pre-intervention.CONCLUSION Positive psychological intervention and control can improve the sleep state and psychological state of officers and soldiers working in confined space at sea.

Twin pregnancy with triple parathyroid adenoma:A case report and review of literature

Primary hyperparathyroidism(PHPT) is rare during pregnancy. A case of twin pregnancy with three simultaneous parathyroid adenomas at the same time has not been reported. Multiple parathyroid lesions are difficult to diagnose, as pregnant women who insist upon continuing a pregnancy are not able to undergo 99mTc-sestamibi scintigraphy, so cases of PHPT are easily unobserved and often can have serious consequences for the patient and the fetus. Therefore, we reported a case of a 28-year-old woman mid-pregnancy with twins, who had hypercalcemia and was eventually diagnosed with twin pregnancy with PHPT due to a triple parathyroid adenoma, had good pregnancy outcomes after undergoing surgery in mid-pregnancy. Twin pregnancy with PHPT due to a triple parathyroid adenoma, as presented in this case, is very rare and surgery in mid-pregnancy is demonstrated here as safe. Intraoperative parathormone monitoring was and remains key to a successful operation.

Slab Analysis of Large Cylindrical Shell Rolling

Considering the characteristics of large cylindrical shell rolling, such as double driving rolls, asymmetrical rolling and huge workpiece, a slab method was developed to establish the rolling force model. In this model, the non- uniform normal and shear stresses and the upper and lower surface temperatures of the workpiece were taken into ac- count. Moreover, the flow stress model, considering the dynamic recovery and dynamic recrystallization behaviors of the material, was established. The rolling pressure distribution, the rolling force, the rolling torque and the neutral points could be calculated quickly and easily by the roiling force model. The predicted results were shown to be in good agreement with the measured values, which indicated that the model can satisfy the requirement of industrial application.

Dynamics of rolling mill drive system considering arc tooth gear dynamic characteristics

The arc tooth gear spindle (ATGS) is the key structure of the drive system of hot finishing rolling mills. To investigate the dynamic characteristics of ATGS of the drive system of hot finishing rolling mills, a dynamic mechanical model of ATGS was established. The influences of dynamic displacement and dynamic torque on dynamic load (meshing force, additional torque and friction torque) were studied during the non-steady-state operation of ATGS. On this basis, a dynamic model of rolling mill drive system was established considering the arc tooth gear dynamic characteristics. The dynamic response of the drive system was simulated and analyzed. The results showed that the nonlinear characteristics of ATGS were obvious;the meshing force (PX and PZ) could restrain the increase in dynamic displacement, which reflected the positive stiffness of ATGS;there was a coupling among the vertical, horizontal and torsional directions in the drive system model considering the dynamic characteristics of the arc tooth gear;the vibration intensity of ATGS in the horizontal direction is greater than that in the vertical direction when the self-excited torsional vibration happens;the greater the axial inclination angle was, the more complex the vibration mode was, and the lower the stability of the drive system was.

Longitudinally profiled plate leveling theory based on linear decreasing leveling scheme

An an alytical model based on linear decreasi ng leveli ng scheme was proposed to inv estigate the longitu din ally profiled plate leveling process.Considering the variable cross-sectional thickness of longitudinally profiled plate and the dynamic reductions in leveling rolls,the reduction models of upper and lower rolls,the leveling force model and the leveling moment model were established,respectively,based on linear decreasing leveling scheme.Moreover,the finite element model of longitudinally profiled plate leveling process was established based on ABAQUS.Then,the total displacements of upper and lower rolls,the leveling force and the stress distribution of longifudinally profiled plate in the leveling process were calculated.To verify the validity of the proposed models,calculated leveling forces were compared with the measured values,and very good agreements are found.Calculated results show that linear decreasing leveling scheme is suitable for leveling longitudinally profiled plate.

Longitudinal profiled plate straightening process based on curvature integral method

Considering the variable cross section thickness of longitudinal profiled plate and the dynamic reductions of straightening rolls,an analytical model combining curvature integral method with linear decreasing straightening scheme was proposed to investigate the longitudinal profiled plate straightening process.Moreover,the calculation flow and solution algorithm of longitudinal profiled plate straightening process were presented.To verify the proposed model,calculated straightening forces were compared with the measured values,and very good agreements were achieved.Then,the reduction,contact angle,reverse bending curvature,residual curvature,straightening force and straightening moment of longitudinal profiled plate in the straightening process were calculated and analyzed,and the calculated results show that the curvature integral method can be used to reveal the mechanism of longitudinal profiled plate straightening.