PDCA循环在预防动脉压迫止血器致皮肤损害中的应用效果

目的通过采用PDCA持续改进肝癌介入术后动脉压迫止血器使用方法,以期减少因动脉压迫止血器致皮肤损害的发生率,减轻患者痛苦。方法选取肝癌介入术后使用动脉压迫止血器患者305例,应用PDCA循环缩短压迫时间、建立皮肤损害高危评估机制,评估患者局部皮肤损害情况。结果通过PDCA持续改进,动脉压迫器所致患者皮肤损害的发生率降低(P0.01)。结论缩短动脉压迫止血器压迫时间、实施皮肤破损高危评估基本解决了介入术后动脉压迫止血器致皮肤损害的问题,在发现、解决护理问题中起到推动作用。     

Centrifugal Compressor Stall Control by the Application of Engineered Surface Roughness on Diffuser Shroud Using Numerical Simulations

Downsizing in engine size is pushing the automotive industry to operate compressors at low mass flow rate. However, the operation of turbocharger centrifugal compressor at low mass flow rate leads to fluid flow instabilities such as stall. To reduce flow instability, surface roughness is employed as a passive flow control method. This paper evaluates the effect of surface roughness on a turbocharger centrifugal compressor performance. A realistic validation of SRV2-O compressor stage designed and developed by German Aerospace Center (DLR) is achieved from comparison with the experimental data. In the first part, numerical simulations have been performed from stall to choke to study the overall performance variation at design conditions: 2.55 kg/s mass flow rate and rotational speed of 50,000 rpm. In second part, surface roughness of magnitude range 0–200 μm has been applied on the diffuser shroud to control flow instability. It was found that completely rough regime showed effective quantitative results in controlling stall phenomena, which results in increases of operating range from 16% to 18% and stall margin from 5.62% to 7.98%. Surface roughness as a passive flow control method to reduce flow instability in the diffuser section is the novelty of this research. Keeping in view the effects of surface roughness, it will help the turbocharger manufacturers to reduce the flow instabilities in the compressor with ease and improve the overall performance.     

呼吸机设备维修分析

呼吸机平时维护很重要,使用者要清楚掌握呼吸机的结构、工作原理都。呼吸机要按要求定期更换部件以确保正常工作,因此使用者要熟练掌握关键部位的装卸,并且要重视呼吸机的维护保障工作。     

超导型磁共振冷头的工作原理及维护保养

冷却系统是超导型磁共振正常运行的重要保障,而冷头是磁共振冷却系统的重要组件。本文着重介绍冷头的工作原理、运行方式及其在使用中的日常维护和定期保养。     

轻便加压舱（袋）专用空压机的研制

本文介绍了轻便加压舱（袋）专用空压机的研制过程、实验方法和性能指标。本空压机与轻便加压舱配套,可充分发挥加压舱救治急性高原病的效用,为高原部队提供了一种十分有效的装置     

医用分子筛制氧机能耗分析

目的：计算分子筛制氧机制取富氧气体的单位能耗,评价其实际运行成本。方法通过空气压缩机机组输入比功率和分子筛输入输出比,计算理论耗电量,然后根据对卸载、干燥等实际影响因素的分析,计算各因素对耗电量的影响因子,并通过实际测试进行验证。结果在理想状态下制取1 m3富氧气体,耗电量为1.54~1.87 kWh;在不考虑增压机耗电量的情况下,分子筛制氧机制取1 m3富氧气体的实际耗电量不低于2 kWh。结论分子筛制氧机单位能耗大,更适用于使用汇流排供氧的医院。     

Experimental Investigation and Optimization of the Semisolid Multicavity Squeeze Casting Process for Wrought Aluminum Alloy Scroll

Scroll compressors are popularly applied in air-conditioning systems. The conventional fabrication process causes gas and shrinkage porosity in the scroll. In this paper, the electromagnetic stirring (EMS)-based semisolid multicavity squeeze casting (SMSC) process is proposed for effectively manufacturing wrought aluminum alloy scrolls. Insulation temperature, squeeze pressure, and the treatment of the micromorphology and mechanical properties of the scroll were investigated experimentally. It was found that reducing the insulation temperature can decrease the grain size, increase the shape factor, and improve mechanical properties. The minimum grain size was found as 111 ± 3 μm at the insulation temperature of 595 °C. The maximum tensile strength, yield strength, and hardness were observed as 386 ± 8 MPa, 228 ± 5 MPa, and 117 ± 5 HV, respectively, at the squeeze pressure of 100 MPa. The tensile strength and hardness of the scroll could be improved, and the elongation was reduced by the T6 heat treatment. The optimal process parameters are recommended at an insulation temperature in the range of 595–600 °C and a squeeze pressure of 100 MPa. Under the optimal process parameters, scroll casting was completely filled, and there was no obvious shrinkage defect observed inside. Its microstructure is composed of fine and spherical grains.     

氨压缩机机械密封泄漏原因分析与维修实践

开启式氨制冷压缩机的机械密封（轴封）是压缩机的重要部件之一,它关系着整个机组的正常运行。经过对机械密封的磨损、泄漏、使用寿命短等事故原因分析,总结出一些方法,从而使机械密封达到了无泄漏工质、微磨损、可靠性高使用寿命长的良好状态,确保了机组正常运行,经济效益显著。     

基于压力监测医用中心压缩空气供应系统

目的：建立能够量化评价医用中心压缩空气供应系统工作状况的指标。方法：根据气体状态方程．以压力变化为监测对象进行参数计算。结果：气体用量的平均速率和瞬时速率、空气压缩机平均排气速率和启停点排气速率、空气压缩机压力-排气速率曲线等参数,可以对医用中心压缩空气供应系统进行客观评价。结论：此方法对加强设备质量管理和维护保养起到重要作用。     

呼吸机空气压缩机输出压力偏低的故障分析与维修

总结呼吸机空气压缩机输出压力偏低的常见故障原因，并介绍其故障分析方法和维修经验，为更好维修呼吸机空气压缩机提供借鉴。