A Method of Reproducing the Triple Point of Mercury in the Working Standards of the Unit of Temperature

A method of replacing the triple point of mercury by the melting point of gallium when reproducing the ITS-90 International Temperature Scale is considered. A method of estimating the systematic error and of determining the conditions under which the method can be used is proposed.     

Isolation of the singularity in the solution of a heat conduction problem

A finite-difference method is used to solve a problem with a singularity in the solution. A scheme suitable for describing the behavior of the solution near the singularity is constructed.     

Measurement of the vibrations of the wires of electric transmission lines by a heterodyne method

A heterodyne instrument for the measurement of the vibration of wires is considered. A measurement circuit is presented and its precision estimated.     

Generalization of the problem of indirectly measuring the distance to a reflecting surface

A general approach is considered to solving the problem of indirectly measuring the distance from an object to a reflecting surface in a given direction. A mathematical formulation of the problem is presented with its general and partial solutions under different conditions. A scheme for applying the method of distance measurement is considered, based on the solution obtained. The accuracy of the method is estimated.Translated from Izmeritel'naya Tekhnika, No. 6, pp. 6–9, June, 1994.     

Quantifying the influence of safety management on the reliability of safety barriers

A methodology is described that enables to use safety management audit assessments and safety culture questionnaire results for estimating the reductions in the reliability of safety barriers in major hazard plants. The critical issue is the establishment of weight factors in combination with the anchoring of “good” safety management. A method is proposed to derive weight factors from statistical accident analysis in combination with a statistical analysis of safety management assessments at a representative sample of major hazard industries. A preliminary set of weight factors is presented with some examples of resulting reductions in reliability—this demonstration confirms that the set of weight factors needs further development.     

Identification of the parameters of the materials of the carrier structures of radio-electronic systems using a computer-aided measuring bench

A method of identifying the physical and mechanical parameters of the materials of the carrying structures of radio-electronic systems is described. A computer-aided measuring bench for solving the identification problem is proposed. Translated from Izmeritel'naya Tekhnika, No. 12, pp. 52–55, December, 1996.     

重力供液系统中过热度对传热面积影响的研究

本文主要对重力供液系统中蒸发器出口制冷剂的过热度进行分析,通过visual basic软件仿真计算出全部用气化潜热制冷需要的蒸发器面积A1,和有过热度后多出来的面积A2。将A1＋A2与蒸发器现有面积进行对比,发现A1＋A2比蒸发器现有面积小,说明现有蒸发器的面积比实际需要的面积要大,因此我们可以减小蒸发器的面积来达到优化蒸发器的目的。     

Evaluation of the accuracy of measuring leads for mapping the electric field of the heart

A lead system is described for measuring the electric field of the heart on the surface of the thorax. It is sufficiently accurate and convenient for electrocardiographic mapping under clinical conditions. A method of quasimultipole approximation of the potential is presented. This is based on the expansion of the latter in a series of spatial spherical functions, and provides accurate interpolation, with simultaneous filtering and removing the uninformative highfrequency spatial components of the measured signals.Translated from Izmeritel'naya Tekhnika, No. 10, pp. 58–62, October, 1964.     

The sedimentation velocity of a particle in a wide range of Reynolds numbers in the application to the analysis of the separation curve

A simple interpolation formula for the sedimentation velocity of a particle, including the limiting cases of small and large Reynolds numbers is proposed. A comparison with other known similar formulas is given.It is shown that the adjustment of sedimentation law is important to describe the hydrocyclones separation curve for large particles.A way of representing the separation curve, which allows justify the assumptions underlying the model of Schubert–Neesse is shown. It is shown that the correction of formula for the sedimentation velocity significantly affects the estimate of the effective coefficient of turbulent diffusion in the apparatus.     

Examination of the effect of the fibrous structure of a lens on the optical characteristics of the human eye: a computer-simulated model

We introduce a model of the human eye for which we take into consideration the laminated nature of lens fibers. The thickness of each lamina is 5.6 μm; thus the lens comprises 300 eccentric lenses of minute dimensions. The index gradient of the lens is such that the index of refraction increases exponentially from the lens core to its peripheral zone. A vector ray-tracing technique is employed to study the optical haracteristics of the system. Both paraxial and marginal rays are simulated, and the angles of incidence vary from 0° to ±20°. Special attention is given to the meridional caustic surfaces as well as the wave-front distortion of the refracted rays. A quasi-Newton optimization technique is employed to obtain the best parameters for the system. A computer modeling program, written in FORTRAN 77, is used to simulate a ray's refraction through the multisurfaces of the eye. The results show full agreement with previous data and that the cornea is responsible for eliminating possible spherical aberration of the system.     

石油渣油制备针状焦研究--中间馏分热反应研究

石油渣油的组成复杂,分子量分布宽,直接焦化不能生产针状焦。采用一定的预处理技术将渣油中适宜制备针状焦的组分保留,可获得理想的焦化原料。通过以辽河减压渣油为原料,经溶剂萃取对渣油进行"掐头去尾"处理,获得了分子量分布窄、杂质含量少的中间馏分A及馏分B。对馏分A、B分别进行热反应研究,结果表明:渣油的预处理效果明显,中间馏分热反应产物具有光学各向异性物含量高、取向性好等特点,是制备针状焦的理想原料。     

Application of the mixed approximation to the solution of two-dimensional problems of the theory of small elastoplastic strains using the finite element method

A triangular finite element that provides the stability and convergence of the mixed approximation is used for the solution of two-dimensional boundary-value problems of the theory of small elastoplastic strains. A system of resolving matrix equations of a mixed type is presented for the solution of which a three-layer iteration algorithm with a preconditioning matrix is used. Numerical results for the solution of model problems obtained by the classical and combined finite element methods are compared. __________ Translated from Problemy Prochnosti, No. 2, pp. 124–136, March–April, 2006.     

An investigation of the metrological characteristics of a virtual instrument for measuring the operating efficiency of hydroelectric equipment

A virtual instrument has been designed to measure the operating efficiency of hydroelectric equipment. A mathematical model of the dynamic systematic error of a measurement is obtained, which is used to optimize the mode of operation of the instrument. A test bench is developed for checking similar virtual instruments. Translated from Izmeritel’naya Tekhnika, No. 10, pp. 43–46, October, 2008.     

Method of Reducing the Error of Transferring the Size of a Unit of Laser Radiation Energy

A method is considered of reducing the error of transferring the size of a unit of laser radiation energy for a secondary standard of the units of average power and energy of laser radiation by using the readings of a relative-level sensor. A procedure is developed for processing the readings of this sensor.     

Experimental Determination of Random Errors of Measuring Systems Utilizing the Concept of the Local Inhomogeneity of Their Characteristics

A study is made of the relative analysis of schemes which make it possible to estimate the random errors of measuring instruments caused by low-frequency fluctuations without using standard instruments and gauges. A choice is made of measurement procedures which possess higher reliability.     

任意矩阵的谱的Euclid距离的估计

设A=A E是A的任意扰动矩阵。本文给出了当A分别是任意Hermite矩阵和可对角化矩阵时。它们谱的Euclid距离的估计。     

On the Performance of the Linear Discriminant Function

Consider the case of a single test unit which must be tested at some level of test stress. Suppose that the test stress level is free to be determined, and that only the survival or nonsurvival of the unit is observed. It is assumed that the unit is designed to withstand a known and specified design stress level. A Bayesian model is developed for determining the required level of test stress which maximizes the expected probability of survival at the design stress level. Engineering experience from similar past tests on similar units is used to fit the model. A practical application illustrates the method. The sensitivity of the procedure to changes in the parameters used in fitting the model is also examined.