浅谈液压系统的负载感应控制技术

负载感应控制有利于提高液压系统的效率和节能,在液压系统中得到了广泛应用。文章介绍了简单的液压系统中的负载感应控制及其原理。     

CCV井下钻井工具及其新工艺、新技术在苏丹油田的使用

在油气勘探开发中,研究先进的钻井工具、新工艺、新技术对降低钻井成本、降低事故发生率、提高钻井效率有着重要意义。钻井过程中发生的轻微的漏失会使钻井工作中断,如井漏得不到及时处理,还会引起井喷和卡钻等事故,CCV(Centurioncirculate valve(可多次开关式循环分水接头))接头的出现,对处理井漏事故复杂提供了工具保证和技术支持。     

倒流防止器装置过流件结构与能量损耗分析

文章在论述止回阀构成的倒流防止器装置结构及工作原理基础上,分析各类止回阀流态与流阻关系,并根据各止回阀过流结构的流阻系数,进行能量损失分析与计算,提出单蝶板型倒流防止器装置具有显著的节能效果,是一种很好的止回阀倒流防止器装置过流部件。     

莆田2#燃机试运缺陷分析处理与总结

莆田燃气电厂在2#机分部试运和总启动过程中,出现了天然气关断阀卡涩、燃机末级叶片温度过高跳机、燃机BPT温差过大造成跳机、IGV阀位偏差大等事故,严重影响了机组的正常调试和安全运行。本文将重点分析2#燃机在启动调试过程中发生问题的原因、处理方法及从中得到的经验教训与总结,希望能对以后同类型机组的安装起到一定得指导性作用。     

热水采暖系统的水力平衡改造

以中航自控所住宅小区热水采暖系统的水力平衡改造为例,论述了由于设计、施工等原因造成的热力管网水力失调问题,介绍了静态平衡阀在解决管网水力失调时的操作方式、理论依据和效果。     

柴油发动机排气门材料浅析

机械零部件的材料对机械零部件的性能有很大的影响,因此在日常的工作中必须加强对机械零部件的材料分析。本文就对柴油发动机排气门材料进行了简要的分析。     

城镇给水一户一表工程探讨

“一户一表”改造工程作为供水行业的重点和难点工程，关系着千家万户的切身利益。通过对河池市金城江给水一户一表工程的探讨，为实施城镇给水一户一表工程提供一些参考，进一步推动给水一户一表工作。     

Cost effectiveness of transcatheter aortic valve replacement compared to medical management in inoperable patients with severe aortic stenosis: Canadian analysis based on the PARTNER Trial Cohort B findings

Abstract

Objective:

The only effective treatment for severe aortic stenosis (AS) is valve replacement. However, many patients with co-existing conditions are ineligible for surgical valve replacement, historically leaving medical management (MM) as the only option which has a poor prognosis. Transcatheter Aortic Valve Replacement (TAVR) is a less invasive replacement method. The objective was to estimate cost-effectiveness of TAVR via transfemoral access vs MM in surgically inoperable patients with severe AS from the Canadian public healthcare system perspective.

Methods:

A cost-effectiveness analysis of TAVR vs MM was conducted using a deterministic decision analytic model over a 3-year time horizon. The PARTNER randomized controlled trial results were used to estimate survival, utilities, and some resource utilization. Costs included the valve replacement procedure, complications, hospitalization, outpatient visits/tests, and home/nursing care. Resources were valued (2009 Canadian dollars) using costs from the Ontario Case Costing Initiative (OCCI), Ontario Ministry of Health and Long-Term Care and Ontario Drug Benefits Formulary, or were estimated using relative costs from a French economic evaluation or clinical experts. Costs and outcomes were discounted 5% annually. The effect of uncertainty in model parameters was explored in deterministic and probabilistic sensitivity analysis.

Results:

The incremental cost-effectiveness ratio (ICER) was $32,170 per quality-adjusted life year (QALY) gained for TAVR vs MM. When the time horizon was shortened to 24 and 12 months, the ICER increased to $52,848 and $157,429, respectively. All other sensitivity analysis returned an ICER of less than $50,000/QALY gained.

Limitations:

A limitation was lack of availability of Canadian-specific resource and cost data for all resources, leaving one to rely on clinical experts and data from France to inform certain parameters.

Conclusions:

Based on the results of this analysis, it can be concluded that TAVR is cost-effective compared to MM for the treatment of severe AS in surgically inoperable patients.     

关于气举井检阀周期统计方法的讨论

分析了气举井检阀周期统计中存在的问题,讨论了影响气举并检阀周期统计的主要因素,推荐了气举井检阀周期的统计方法,对油田现场气举井检阀周期的统计及量化气举井的技术管理水平具有一定指导意义.     

广西左江山秀水电站船闸下沉式工作门液压系统改造分析

施工单位按厂家原图在对广西左江山秀水电站船闸下沉式工作门及液压启闭机进行安装调试过程中发现,当工作门在由静止状态变为启门状态时,液压启闭机左右两侧油缸工作同步偏差过大,造成液压系统故障停机。为解决此故障,对原液压系统设计进行了局部修改,解决了液压启闭机左右两侧油缸工作同步偏差过大的问题,顺利完成了下沉式工作门及液压启闭机的安装调试工作。