Development of an austenitic chromium-manganese steel with high hydrogen resistance

We compare the results of studying the effect of hydrogen on the characteristics of short-time strength and low-cycle durability of austenitic stainless steels and age-hardening alloys. We show that austenitic stainless 06Kh20N16G6AF steel with solid-solution strengthening and the optimal content of nickel, manganese, and nitrogen possesses high mechanical characteristics and is least inclined to hydrogen degradation. __________ Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 41, No. 5, pp. 95–100, September–October, 2005.     

Stochastic stabilization of differential systems with general decay rate

Some sufficient conditions concerning stability of solutions of stochastic differential evolution equations with general decay rate are first proved. Then, these results are interpreted as suitable stabilization ones for deterministic and stochastic systems. Also, they permit us to construct appropriate linear stabilizers in some particular situations.     

Carbon nanotube field emitters for planar emission vacuum micro-and nanoelectronics

The design and manufacturing technology of carbon nanotube field emitters for novel devices of planar emission vacuum micro-and nanoelectronics are described. Prototypes of diode structures with such emitters are obtained in which the threshold field strength amounts to ～2 V/μm and the direct to reverse current ratio exceeds 10⁵. The obtained small scatter of characteristics points to the possibility of creating integrated circuits possessing high operation speed and a working temperature range expanded from ?60 to +30°C.     

Experimental Study of the Deformation of Instantaneous Neutron Spectra from the Fission of <Superscript>235</Superscript>U Nuclei in Fast-Reactor Core Materials

The results from studies of the deformation of the instantaneous neutron spectra resulting from the fission of ²³⁵U nuclei in the material of structural elements of a fast reactor core are presented. The neutron spectra at and near the center of the reactor core were measured using neutron activation and fission neutron detectors.__________Translated from Pribory i Tekhnika Eksperimenta, No. 4, 2005, pp. 15–25.Original Russian Text Copyright © 2005 by Sevast’yanov, Koshelev, Maslov.     

Problems of nondestructive testing of wheel-pair components of rolling stock

Improving the effectiveness of nondestructive testing of railway rolling stock’s wheel-pair components during their manufacturing and repair is considered. The results of metallographic studies of PY-1 and PY-1III solid-rolled wheels and axles, analysis of the operating specifications, and experimental studies of the optimal methods of nondestructive testing are included.     

Temperature Induces Self-assembly of Silicon Nano/Micro-structure based on Multi-physics Approach

A three-dimensional dynamic model for nano/micro-fabrications of silicon was presented. With the developed model, the fabrication process of silicon on nothing (SON) structure was quantitatively investigated. We employ a diffuse interface model that incorporates the mechanism of surface diffusion. The mechanism of the fabrication is systematically integrated for high reliability of computational analysis. A semi-implicit Fourier spectral scheme is applied for high efficiency and numerical stability. Moreover, the theoretical analysis provides the guidance that is ordered by the fundamental geometrical design parameters to guide different fabrications of SON structures. The performed simulations suggest a substantial potential of the presented model for a reliable design technology of nano/micro-fabrications.     

新型多苯并咪唑环芳识别氨基酸甲酯的分子动力学和密度泛函研究

采用Gaussian 03在B3LYP/6-31G(d)水平上分别优化新型多苯并咪唑环芳(MBICP)受体和氨基酸甲酯(AAME)配体,再用基于模拟退火的分子动力学方法 CDOCKER将配体与受体对接,对每一个复合物获得了一组最低能量的初始构象。最后用Turbomole在BLYP/def-TZVP水平对初始构象进一步优化,并对收敛后的复合物最低能量构象作NBO分析。以密度泛函理论计算获得的相互作用能作为核心参数,采用组合策略建立了表达MBICP-AAME复合物结合常数的定量关系模型,计算了该类复合物的结合常数。对MBICP受体和AAME配体间的作用模式以及影响MBICP受体识别AAME配体的主要因素,作了深入讨论。     

Elastic behaviour of polyvinyl chloride melts

A study has been made of the elastic behaviour of Polyvinylchloride commercial samples at high shear stresses, under similar conditions to those used in the processing industry, by means of an extrusion capillary rheometer.The influence in the die swell of variables as molecular weight, temperature and shear rate has been studied. Results are in agreement with general literature data.Smooth extrudates are obtained only in the zone of intermediate shear rates. In this zone it is observed that the die swell increases with shear rate.     

Forecasting with unequally spaced data by a functional principal component approach

The Principal Component Regression model of multiple responses is extended to forccast a continuous-time stochastic process. Orthogonal projection on a subspace of trigonometric functions is applied in order to estimate the principal components using discrete-time observations from a sample of regular curves. The forecasts provided by this approach are compared with classical principal component regression on simulated data.