螺内酯治疗慢性充血性心力衰竭的临床观察

目的观察小剂量醛固酮拮抗剂螺内酯治疗慢性充血性心力衰竭(CHF)的有效性和安全性。方法选择各种心血管疾病所致的CHF患者64例,随机分为治疗组(A组32例)和对照组(B组32例),二组均给予常规综合疗法抗CHF治疗,A组联用螺内酯(20mg/d)治疗前和治疗后6个月分别进行心功能(NYHA)分组评估、超声心动图及生化检查,同时观察6min步行试验,并进行对照。结果治疗6个月A、B组心功能分级LVEF、SV、CI)和6min步行距离较治疗前均显著改善(P<0.05)与B组比较,A组改善最显著(P<0.05)。未发现严重高血钾及其他严重不良反应。结论应用螺内脂治疗CHF疗效肯定,安全性高。     

±800kV特高压换流阀运行试验系统研发

根据特高压直流输电工程发展的需要,研发了6500A/50kV特高压换流阀运行试验系统。参照云广±800kV直流输电工程的系统设计,介绍特高压工程运行试验的预期参数和论述试验系统原理;依据IEC60700-1和GB/T20990.1高压直流输电换流阀电气试验标准,在新研发的运行试验系统上实现了能够满足特高压换流阀要求的全套运行试验项目。     

6106型柴油机排气阀失效分析

6106型柴油机在载重车上运行4万公里和8万公里后发生排气阀"掉头"和"掉块"事故,本文对失效排气阀的金相组织和断口进行了观察分析,分析结果表明,金相组织正常,可以排除冶金质量和热处理的问题,发生在颈部的"掉头"事故,是由于机加工精度不高,表面存在"沟槽"引起.发生在盘部的"掉块"事故,是由于21-4N钢高温强度不足引起的.     

New rotary valves for pulse-tube refrigerators

In most used rotary valves in GM-type pulse-tube refrigerators the rotor makes heavy mechanical contact with the stator, so the valve is liable to wear, and large torques are needed. In this paper we will describe two types of valves, which have balanced forces on the rotor. In the first valve the rotor and the stator make no mechanical contact. The second type is a contact valve, like the classical valves, but the forces on the rotor are balanced in a different way. Therefore, these valves are less liable to wear, and the torques needed to rotate the valves are small.     

3种材料及不同硬度下对超高压卸压阀阀芯寿命的影响

通过对超高压容器加压、保压、卸压的实验,研究了影响超高压卸压阀寿命的2个因素:材料种类和硬度。实验结果表明:材料的种类对阀芯寿命影响很大,45钢的寿命明显低于其余2种合金钢阀芯的寿命,GCr15的寿命次之,高速钢W18Cr4V阀芯的寿命最长;材料的硬度对阀芯寿命也有较大的影响,随着材料硬度的提高,阀芯寿命也随之提高。     

基于心形孔的Hy-Vo齿形链的啮合分析及其设计方法

基于Hy-Vo齿形链与链轮刚柔传动的啮合原理及其链轮滚刀与链轮的滚切原理,以Hy-Vo齿形链工作链板齿形视作滚刀法向齿形的设计理念,建立基于心形孔的Hy-Vo齿形链—链轮—刀具齿条的啮合设计体系;根据Hy-Vo齿形链链轮与刀具齿条的共轭啮合条件,提出当工作链板齿形角不等于渐开线齿形链轮压力角时的参数变换的啮合设计方法,并进行实例设计计算。通过171 h台架磨损试验,研究该新型Hy-Vo齿形链的耐磨特性,由于该新型Hy-Vo齿形链链板孔形状类似心形,组成异型销轴截面的各段圆弧均为外凸曲线,因而异型销轴与链板心形孔外侧曲线定位时,比圆形基准孔和长腰形基准孔更稳定,接触面积更大,该新型Hy-Vo齿形链具有较高的耐磨性,试验研究表明,这种新的啮合设计体系和设计方法是科学的,是切实可行的。     

(31)P-MR Spectroscopy for the evaluation of energy metabolism in intact residual myocardium after acute myocardial infarction in humans

Objective experimental studies have demonstrated that acute myocardial infarction (MI) alters energy metabolism even in non-infarcted adjacent tissue. In patients with subacute MI, the influence of the regional ischemie insult on energy metabolism of intact septal myocardium was analyzed using³¹P-Magnetic resonance spectroscopy (MRS). Patients and Methods in eight patients with wall motion abnormalities in the anterior wall³¹P-spectra were obtained from non-infarcted adjacent scptal myocardium, as well as infarcted anterior myocardium (voxel size 25 ccm each) 29 ±8 days after MI using a 3D-CSI technique. Additionally, cardiac function was analyzed using breath-hold cine MRI. MR1 was repeated 6 months after revascularization to assess viability of infarcted segments. Eight age-matched healthy volunteers served as control group. Results according to follow-up MRI 4/8 patients showed regional wall motion recovery. Here, PCr/ATP-ratios were not significantly reduced in intact septal myocardium as well as infarcted anterior myocardium compared to healthy volunteers (1.28 ±0.10 and 1.14 ±0.09 vs. 1.45 ±0.29). No recovery of regional function was detected in 4/8 patients with —therefore—non-viable anterior myocardium. PCr/ATP-ratios were significantly reduced in intact and infarcted myocardium compared with healthy volunteers as well as to patients with wall motion recovery (0.77 ±0.17 and 0.49 ±0.23;P < 0.05). Discussion these preliminary results indicate that energy metabolism is reduced in patients with persisting wall motion abnormalities after myocardial infarction and revascularization in ischemically injured as well as in adjacent non-injured myocardium.     

抗磨损密封自补偿渣浆闸阀研究

以目前国内外火力发电厂普遍使用的渣浆闸阀为研究对象，对其工作环境、运行条件和方式、内部结构、密封性能、磨损情况以及其他失效形式进行了调查研究．分析了该类阀门在使用过程中表现的不足之处（如漏流、磨损、腐蚀都比较严重），以及其产生的原因．研制出一种新兴的渣浆闸阀，克服了常规阀门抗磨损耐腐蚀能力差、密封不严、无补偿密封、使用寿命短等问题     

双机热备方案探讨

目前自动化程度高,各单位对服务的安全性、可用性、依赖性变大。24小时不允许停机,在这种情况下,服务器的双机热备就显的非常必要及迫切。双机热备是近年来服务器端的安全性,可用性的一次重大的革命。从以前加大的硬件可用性,到现在的双机要备用,来保证服务器的不停机运行,是可用性的一次重大进步。     

减温减压调节阀在蒸汽系统应用探讨

分析乌鲁木齐石化公司二化肥蒸汽系统HV-112、PV-172A两阀泄漏及事故原因,提出调节阀选型的重要性,生产实践证明瑞典BTG减温减压调节阀在蒸汽系统的应用是成功的。