航空发动机装配标准工时及工位能力优化研究

制定了航空发动机装配现场标准工时数据库,能够有效改善装配科室生产效率,为生产标准化提供了基本依据;并建立了装配技能矩阵,能够准确评估发动机各装配工位的作业水平,预判产出能力,为生产计划的下达及技能人才的培养方向提供了支撑依据。经对比,按技能矩阵优化后的工位能力模型进行生产计划的下达更为科学准确,解决了航空发动机装配现场生产工时的标准化问题,并依托装配技能矩阵的建立对生产计划进行了优化迭代,提高了航空发动机装配现场的生产管理水平。

关于船厂工位能力配置与造船周期的关系

缩短造船周期是提高现代造船生产效率的永恒的话题。如何达到缩短造船周期的目的，本文从造船工位能力配置的视角，简明分析了两者之间的依存关系，以寻求一种最佳的生产组织方式。

Exploring the employment readiness and return to work status of breast cancer patients and related factors

Objective:To investigate the employment status,employment readiness,and other factors affecting the ease or difficulty with which breast cancer patients effect their return to work(RTW).Methods:This study adopted a mixed-method design,recruiting participants from among breast cancer patients in a cancer hospital in Hunan from December 2018 to June 2019.We approached 300 individuals,192 of whom ultimately participated in this study.The quantitative part of the study involved several scales:the Patient Health Questionnaire-9(PHQ-9),the Brief Fatigue Inventory(BFI),the Work Ability Index(WAI),and the Lam Assessment of Employment Readiness(LASER).The qualitative part involved a set of open-ended questions and written responses collected from 41 participants who had already returned to work at the time of data collection.Their written responses mainly concerned factors influencing RTW.Results:Forty-one breast cancer patients had returned to work.The results reported a median total Cognitive Symptom Checklist score of 9.00(6.00,15.25),a median WAI score of 5.00(3.50,9.75),a median BFI score of 26.00(14.75,42.00),a median total PHQ-9 score of 8.00(5.25,17.00),and a LASER score of 50.35±11.90.Multiple regression analysis showed that the participants’cancer stage,cognitive limitations,depression,fatigue,and work ability were significant predictors of employment readiness(P<0.05).Exploring the qualitative data,we found that higher skill levels,better social support,and a flexible work schedule facilitated RTW;stress,lack of confidence in one’s work skills,depression,and fatigue are all possible barriers to RTW.Conclusion:The findings indicate that breast cancer patients have a low level of employment readiness.Nurses and other healthcare providers can develop relevant interventions to promote employment readiness and ultimately achieve RTW in this study population.

Mechanical properties and microstructure evolution of an Al-Cu-Li alloy subjected to rolling and aging

The mechanical properties and microstructure of Al-Cu-Li alloy sheets subjected to cryorolling(-100 ° C,-190 ℃) or hot rolling(400 ℃) and subsequent aging at 160 ℃ for different times were investigated. The dynamic precipitation and dislocation characterizations were examined via transmission electron microscopy and X-ray diffraction. The grain morphologies and the fracture-surface morphologies were studied via optical microscopy and scanning electron microscopy. Samples subjected to cryorolling followed by aging exhibited relatively high dislocation densities and a large number of precipitates compared with hot-rolled samples. The samples cryorolled at-190 ℃ and then aged for 15 h presented the highest ultimate tensile strength(586 MPa), while the alloy processed via hot rolling followed by 10 h aging exhibited the highest uniform elongation rate(11.5%). The size of precipitates increased with the aging time, which has significant effects on the interaction mechanism between dislocations and precipitates. Bowing is the main interaction method between the deformation-induced dislocations and coarsened precipitates during tensile tests, leading to the decline of the mechanical properties of the alloy during overaging. These interesting findings can provide significant insights into the development of materials possessing both excellent strength and high ductility.

Testing Thermal Properties of Cooling Device with Heat Pipes to Improve His Heat Transfer Ability

This paper deals about testing thermal properties of the cooling device with heat pipes at inclination position, in consequence of using the natural convection to improve heat transfer properties. Head point testing of cooling device is monitoring temperature on the aluminium block of energy converter, heat pipes and ribs under temperature condition 30 ℃ in thermostatic chamber. Testing of the device was performed at tilt angles positions 0, 10 and 20° from the vertical level. The heat flux loaded to energy converter was 450 W. The next goal of the paper is to research on influence working position of the wick heat pipe on their thermal performance. In this research heat pipes were made with capillary structure sintered from copper powder granularity 100, 63 and 50 μm filled with water and ethanol. Next heat pipe thermal performance was performed by measuring heat source and working positions. Knowledge of these two research goals can bring potential improvements in purpose of cooling device for effective heat sink from high power electronic components.