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1.
M. M. Gadenin 《Inorganic Materials》2013,49(15):1352-1356
It is shown that conditions of attainment of marginal states in the material of structural components are formulated on the basis of analysis of force and deformation criteria of formation and development of destruction. The parameters of these criteria are data on types of structural materials, standard and special characteristics of their mechanical properties, structural forms of considered elements of the equipment, and their operating stress loading. In this case, the construction of a system of state equations for describing interrelation of current damage, external actions, and responses to them is based on the concept of calculating variations in properties of materials at all stages of the design life cycle. 相似文献
2.
O'Brien RS 《Radiation protection dosimetry》2003,105(1-4):95-100
Australia has several uranium mines and a large number of mineral sand mines, with associated processing facilities. Exposures resulting from these mining and processing operations usually involve intakes of mixtures of radionuclides. This work describes the development of a suite of first order, linear compartment models, based on the ICRP Publication 66 respiratory tract model, and an analytical solution to the decay equations, for assessing the consequences of such intakes. The computer programs based on these models directly compute excretion, organ retention and organ and whole-body doses for intakes of either single radionuclides or any mixture of radionuclides belonging to the same radioactive decay chain. The intake can be via inhalation, ingestion or injection, and can be acute, chronic or of limited duration. The starting concentration and degree of secular (dis)equilibrium can be specified for each radionuclide. No assumptions need to be made about the relative magnitudes of the radioactive half-lives of the different nuclides. 相似文献
3.
介绍了用众数法评价方波幅度时的不确定度分析和评价过程;讨论了主要的不确定度来源,包括众数判别区间的影响、波形测量系统幅度测量误差的影响等等;给出了减小不确定度的主要措施,并结合一个实例,给出了方波幅度的不确定度评价结果。 相似文献
4.
M. V. Velasco A. Munoz-Ruiz M. C. Monedero M. R. Jim nez-Castellanos 《Drug development and industrial pharmacy》1995,21(20):2385-2391
In early paper we have studied the flow parameters of powders using a ring shear. Also, we have evaluated an adequate method to estimating flowability according to powder characteristics. The goal of this article is the study of the action of three lubricants, magnesium stearate, PRUV® and PRECIROL®, on the flowability of an excipient for direct compression, Maltrin® M510. Flow characteristics are evaluated with flowrate, repose angle and compressibility. The influence of concentration and mixing time is also evaluated. Compressibility did not discriminate the lubricant effect. The maximum correlation coefficient flowrate and the repose angle showed the best flowability for magnesium stearate mixtures. 相似文献
5.
Liebert A Wabnitz H Grosenick D Möller M Macdonald R Rinneberg H 《Applied optics》2003,42(28):5785-5792
A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue. 相似文献
6.
On the basis of an analysis of the principle underlying the construction of standards and systems designed for reproduction
of the unit of mean power and energy of laser radiation, it is shown that these standards consist of unified subsystems that
carry the principal metrological load. By means of such a division, it is possible to realize a systems-engineering synthesis
of standards with preassigned error.
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Translated from Izmeritel'naya Tekhnika, No. 11, pp. 20–23, November, 2005. 相似文献
7.
Conclusions The analysis results show that in the presence of hydrogen the nonstationary nature of the thermal effects (heat changes, thermal cycles) in the presence of heterogeneities may on its own be a factor causing a high risk of hydrogen degradation and may be of the implicit type (hidden). The degree of risk depends, in particular, on the kinetics of thermal processes. These defects must be taken into account by estimating the properties of materials after the effect of hydrogen and solving the problems of ensuring safety of structures both in the design stage and controlling efficiency and in determining the optimum (permissible) operating conditions, and also in determining the residual service life. In certain cases the conditions of transition of thermal processes may be of controlling importance for the efficiency of materials in structures.Translated from Fiziko-Khimicheskaya Mekhanika Materialov, No. 6, pp. 7–20, November–December, 1992. 相似文献
8.
M. M. Khasanov É. U. Mamadzhanov 《Journal of Engineering Physics and Thermophysics》1994,66(5):508-514
Theoretical and experimental investigations of localized structures appearing in filtration of nonlinear viscoplastic drilling fluids are reported. The depth of penetration of mud into a porous medium is shown to be dependent on the rate of change of the pressure on the boundary. This fact has been suggested for use in creation of colmatage barriers that prevent penetration of drilling mud into strata.Central Asia State Scientific-Research and Design Institute of the Gas Industry, Tashkent, Uzbekistan. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 66, No. 5, pp. 573–579, May, 1994. 相似文献
9.
《Drug development and industrial pharmacy》2013,39(20):2385-2391
AbstractIn early paper we have studied the flow parameters of powders using a ring shear. Also, we have evaluated an adequate method to estimating flowability according to powder characteristics. The goal of this article is the study of the action of three lubricants, magnesium stearate, PRUV® and PRECIROL®, on the flowability of an excipient for direct compression, Maltrin® M510. Flow characteristics are evaluated with flowrate, repose angle and compressibility. The influence of concentration and mixing time is also evaluated. Compressibility did not discriminate the lubricant effect. The maximum correlation coefficient flowrate and the repose angle showed the best flowability for magnesium stearate mixtures. 相似文献
10.
空调冷源的环境性能比较 总被引:8,自引:0,他引:8
根据国际标准化组织的生命周期评价标准,建立了空调冷源的能量生命周期清单模型,提出了环境影响评价方法.对常见的空调冷源(离心机组、螺杆机组、风冷热泵、天然气直燃机、柴油直燃机、蒸汽双效嗅化锂机组)进行了生命周期清单分析和环境影响评价,并利用权重三角形解释了权重对综合评价结果的影响.综合评价结果表明:电力结构对离心机组的环境性能影响较大,但对天然气直燃机影响较小.因此天然气直燃机和离心机组的环境性能比较应考虑电力结构的影响,在我国1999年的电力结构下,天然气直燃机的环境性能优于离心机组,在我国2010年的电力结构下,两者的环境性能相当,在美国1999年的电力结构下,天然气直燃机的环境性能比离心机组差. 相似文献
11.
12.
在KDON-6000/3500型空分设备调试过程中,由于经验不足、操作不当,造成主换热器发生过冷故障。停运一台膨胀机,采用液氧返充操作使空分设备恢复正常工况。介绍故障发生经过和原因分析过程,以及防止同类故障再次发生的预防措施。 相似文献
13.
A criterion is proposed which enables breakdown of the parabolic model of heat conduction for isotropic materials, in which
there are no phase transitions, to be revealed, and which defines the conventional boundary between the linear and nonlinear
regimes of nonequilibrium thermodynamics in heat problems.
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Translated from Izmeritel’naya Tekhnika, No. 6, pp. 38–42, June, 2008. 相似文献
14.
V. V. Krivenyuk 《Strength of Materials》1990,22(5):658-663
The article analyzes the problem of the necessity of systematizing the known data on the mechanical properties of heat-resistant steels and alloys with the object of improving the effectiveness of checking the possibilities of the constructed equations of state. It substantiates one of the variants of describing the regularities of instantaneous and short-term strain, creeps, stress relaxation, and creep limit from the same positions. 相似文献
15.
通过对影响多武器同时射击安全的重要因素——射面交叉的研究,分析了产生射面交叉的原因,建立了射面交叉的判断模型,研究了控制武器的方法,建立了禁止射击信号的产生模型。研究结果对舰艇的总体设计、武器控制以及作战使用有一定的指导意义。 相似文献
16.
F. A. Makarenko 《Measurement Techniques》1993,36(6):658-661
A new formulation and solution of the problem of calculation of orbits of best approach is discussed. A qualitatively analytical approach to the organization of observations of the motion of artificial Earth satellites is used that makes it possible to calculate and to allow for optimal celestial-mechanics conditions, and to eliminate the effect of systematic observation errors, the effect of the Earth's gravitational field, and other regular perturbations on the solution accuracy.Translated from Izmeritel'naya Tekhnika, No. 6, pp. 28–29, June, 1993. 相似文献
17.
We develop a new approach to the investigation of the effect of inhibitors of hydrogenation of the base in the process of
electrodeposition of metals. We established the relationship between the structure of molecules of the inhibitor, their ability
to interact with atomic hydrogen, their adsorption properties, the contents of various forms of hydrogen in steel, and physicomechanical
parameters of the latter. On the basis of the results of quantum-chemical computations of electron parameters of molecules,
we demonstrate the possibility of prediction of the efficiency of inhibitors of hydrogenation and regularities of changes
in the strength and plastic properties of steel.
Dnepropetrovsk State University, Dnepropetrovsk. Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 32, No. 6, pp.
7–17, November–December, 1996. 相似文献
18.
G. A. Frolov 《Journal of Engineering Physics and Thermophysics》1986,50(4):448-452
An experimental determination is made of the dependence of the gasification parameter and effective enthalpy on stagnation enthalpy and the fraction of the radiant component of a heat flow.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 50, No. 4, pp. 629–635, April, 1986. 相似文献
19.
V. A. Sandovskii 《Measurement Techniques》2010,53(4):426-430
It is shown that the velocity of propagation of an electromagnetic field in samples of extended shape with a constant cross
section depends on the structure of the sample material, its magnetic properties and, in particular, the viscosity, shape
and dimensions of the cross section and the excitation frequency. 相似文献