考虑弹性变形的不同综合曲率下的滑动副油膜计算

本文介绍了考虑滑动副中较软元件弹性变形及贫油状态的滑动副承载能力计算,其中变形计算采用了半无限体法,并参照联邦德国Bernd Schaude著作采用了简化的处理方法,大大简化了计算过程,且便于利用油压分布计算中的差分格式。为了保证计算精度,减少计算时间,采用了合理划分网格,合理选定计算顺序和设法加速收敛等措施。     

尺寸链的列表计算法

本文提出了一种尺寸链的列表计算法,它通用于线性尺寸链的各种计算中,由于避免了在计算中使用各种繁杂的公式,使尺寸链的计算简便了。     

油田自喷井井底流压计算方法研究及应用

在矿场上,井底流压的测试是一种常见的方法,但由于多方面的原因,使得许多井缺乏井底流压数据。因此借用一些计算方法进行井底压力的计算是十分必要的。本文在前人的工作基础上,分析不同流动形态时的空隙率与压降梯度的关系,建立了利用生产数据计算自喷井井底流压的方法,并用实例进行了验证。计算结果与实测值较为接近,能满足工程计算要求。     

液晶嵌段共聚物的微相分离

用分子结构参数计算了一类含有液晶聚酯和聚乙二醇的嵌段共聚物的无扰尺寸和扩展因子 ,进而应用Meier的微相分离理论对该类液晶嵌段共聚物的微区尺寸进行了理论计算 ,并用透射电镜测试了该液晶嵌段共聚物的微区尺寸 ,实验结果与理论计算值相符 .     

滚刀齿形计算的新方法——兼论奥利弗(Oliver)定理的局限性

本文在总结滚刀齿形各种计算方法的基础上,提出了一种新的既简单实用,又精度高的滚刀齿形计算法;阐明了工件节圆半径变动计算的新概念,推导了计算滚刀齿形的各参数之间的相互关系,论述了奥利弗定理在滚刀设计中应用的局限性。     

U型科里奥利质量流量计的力学分析与灵敏度计算

建立了Ｕ型科氏质量流量计的力学模型，研究了其灵敏度系数的计算方法，讨论了约束的影响。所得计算公式得到有限元计算结果的验证。     

对SPSS统计软件中Mcnemar检验结果的讨论

目的：比较手工计算与SPSS软件计算Mcnemar检验的结果,分析结果不一样的原因。方法选取相关书籍上配对设计资料的应用实例,用两种方法计算：一是利用Mcnemar检验公式进行手工计算,二是用SPSS统计软件计算,比较两种计算方法的结果有何不同。结果手工计算的结果为P=0.001,SPSS软件计算的结果为P=0.002,两种方法的结果有出入。结论SPSS统计软件对配对设计四格表资料进行计算时采用的是一种精确检验,运用的是二项分布原理,虽然与手工计算的结果有些出入,但无论用哪种方法都不会影响到最终的统计推断。     

盘形凸轮机构几何尺寸的计算及计算机辅助设计

本文从简单的几何图形出发,对移动和摆动滚轮从动件盘形凸轮机构几何尺寸的计算提出了一套简便而行之有效的方法,尤其是凸轮廓线曲率半径的精确计算,并为这类机构的机辅设计提供了一套程序流程图。     

几种醇类物的荧光效率及荧光寿命研究

以硫酸奎宁稀溶液为参比,计算了7种醇类物的荧光量子效率。结果发现这几种醇类物的荧光量子效率较低,属于弱荧光物质;作者对不同体积比的甲醇-乙醇混合溶液的荧光量子效率进行了计算,发现存在着最佳体积比使荧光量子效率达到最大;同时,通过Forster公式对这7种醇类物的荧光寿命进行了计算,其数值均处在荧光寿命允许的范围内,进一步证明了紫外激励下这几种醇类物质发射的光是荧光,为醇类物质的进一步深入研究提供了依据。     

活塞环自由型线计算方法的比较

论述活塞环径向压力分布函数的一般形式，归纳、总结由径向压力分布求解自由状态型线的方法，对各种计算方法进行了分析比较.实际计算结果表明，各种计算方法之间误差较大，实际应用中采用能量法较宜.     

A short-time-delay urinary flowmeter

A urinary flowmeter has been designed, using a quickly rotating disc and a balance principle. The flowmeter has a fast and accurate response to changing flows. The time delay of the flowmeter is less than about 0.25 s. The improved accuracy in recording urinary flow using the presented flowmeter should make it possible to extract more information from the detrusor pressure and urinary flow relations, relevant for assessing lower urinary tract function.     

Free flap monitoring using a microcomputer linked to a laser Doppler flowmeter

The problems of free flap monitoring using the Periflux PF108D laser Doppler flowmeter (PLDF) are discussed, as are the indices of flap perfusion that the laser Doppler flowmeter can provide. The use of a microcomputer linked to a laser Doppler flowmeter by a suitable interface and using an appropriate monitoring program is described together with details of the system and program. It is suggested that linkage with a microcomputer offers a relatively simple, low cost method of improving the ease and reliability of free flap monitoring with the laser Doppler flowmeter.     

The Ejector Flowmeter and Its Clinical Application

The ejector flowmeter is designed for the quantitative removal of excess anaesthetic gases.
By passing compressed air or gas at 2.0-3.5 kg/cm² pressure through a narrow injector nozzle across the upper end of an ordinary flowmeter tube, a sufficient vacuum is created in the flowmeter to obtain an adjustable removal of gas through the flowmeter; for instance, an anaesthetic gas mixture. The driving gas conveys the anaesthetic gas mixture through a narrow antistatic rubber tube to the nearest ventilation channel or along the floor or ceiling into fresh air through an opening in an outer wall.
The ejector flowmeter may be mounted on any anaesthetic machine, being independent of national standard dimensions. It can be attached to all current anaesthetic circuits, including those with an anaesthesia ventilator. The float secures visual control of proper flowmeter function. The evacuation capacity is adjustable up to 15 1/min, and the full capacity is 20-25 1/min. The consumption of driving gas is about 6 1/min. This elimination of gas involves no explosion risk.     

A Transportable Ejector Flowmeter

A transportable ejector flowmeter for the complete removal of anaesthetic gases from operating theatres and anaesthetic rooms is described. The ejector flowmeter can also be employed as a suction unit driven by compressed air.     

INACCURACY OF ANAESTHETIC FLOWMETERS CAUSED BY STATIC ELECTRICITY

An account is given of types of anaesthetic flowmeters, andit is shown that sticking of the flowmeter bobbin due to accumulationof static electricity may cause a flowmeter inaccuracy of 35per cent as an average. Possible precautions against this causeof error are discussed.     

Measurement of volume and flow in gases

The measurement of volume and flow of the gases which are used during anaesthesia and in the intensive care environment is standard in modern anaesthesia practice. This is done using both electronic and non-electronic equipment. It is essential to have a thorough understanding of the basic principles of the measurement techniques used in these pieces of equipment. This is necessary for proper interpretation of the clinical data; thus, helping directly and indirectly to improve patient care. This article deals with the flow and volume characteristics of gases and the factors affecting them that lead to different types of flows. The article then discusses the core principles of different measurement techniques that are commonly used in routine clinical practice. These measurement techniques include the spirometer, vitalograph, Wright’s respirometer, Drager volumeter, gas meter, pneumotachograph, peak flowmeter, hot wire anemometer, ultrasonic flowmeter, Venturi tube flowmeter, Pitot tube flowmeter, rotameter and mechanical flow transducer. The advantages, disadvantages and common problems associated with these measurement techniques are discussed briefly.     

Hypoxic gas mixtures delivered by anaesthetic machines equipped with a downstream oxygen flowmeter

The oxygen concentration of fresh gas mixtures delivered to a Bain circuit by a Boyle's anaesthetic machine equipped with leaking oxygen flowmeters was measured at the common gas outlet during free flow and during controlled ventilation of a model lung. The results demonstrate that, despite satisfactory oxygen and nitrous oxide rotameter settings, such a machine can deliver hypoxic fresh gas mixtures irrespective of whether the leaking flowmeter is mounted downstream or upstream. This selective loss of oxygen increases with the size of the leak and increases with the back pressure on the flowmeter assembly during controlled ventilation. A downstream position of the oxygen flowmeter should not be regarded as foolproof. Continuous monitoring of the oxygen concentration of fresh gas mixtures with an in-line oxygen analyzer is recommended.     

The hot-film anemometer--a method for blood velocity determination. II. In vivo comparison with the electromagnetic blood flowmeter

Using a constant temperature hot-film anemometer and an electromagnetic blood flowmeter, volumetric flows and velocity profiles were registered in the pulmonary artery, ascending aorta, abdominal aorta and superior vena cava of mongrel dogs. The anemometer registered in 3 out of 4 dogs in the ascending aorta and in 4 out of 5 dogs in the pulmonary artery. The flow profile in these two vessels was flat with a slight deviation with the highest velocity nearer to the posterior wall. In the abdominal aorta the flow profile was sinusoid and in the superior vena cava irregular. In 22 simultaneous measurements anemometer mean results were 97 +/- 23% (+/- SD) of flowmeter results and peak results correspondingly 113 +/- 23%. None of these differences were significant. It is stressed that both qualitatively and quantitatively hot-film anemometer results are comparable to electromagnetic flowmeter results. However, certain differences have been demonstrated.