天然气站场埋地管道检测评价技术优化

作为管道输气系统的重要环节——天然气站场,在保障管道系统安全平稳地集输天然气运行过程中,发挥着至关重要的作用。腐蚀问题极易造成气田生产过程中集输管道的腐蚀穿孔、断裂,严重影响气田的正常生产,同时造成环境污染和威胁人身安全。站场管道输送介质比较恶劣及投产时间较长,且埋地管道的监测和检测一直是难点。为判断其是否存在安全隐患,降低运行风险,需对站场埋地管道检测技术进行优化,提出系统的检测评价流程,采取针对性的检测技术以及明确检测部位,同时选择所发现缺陷的评价标准,从而控制油气站场的风险水平,使其在合理的、可接受的范围内。     

Modernization of the MAS-1 microscope for use in measurements of the spectra of internal conversion electrons

Efforts to increase the speed with which microscopic objects are measured are described. These efforts include the modernization of the MAS-1 automatic scanning microscope and the development of programs to reach an initial point and for carrying out automatic point-to-point linear transitions with a specified step. The error in realizing a transition to a given point with specified coordinates is shown to amount to 1 μm. Translated from Izmeritel’naya Tekhnika, No. 1, pp. 22–24, January, 2009.     

建筑工程项目成本管理内控机制探讨

针对建筑工程成本管理在建筑企业管理中的重要性,介绍了工程项目成本管理内控机制的基本内容,具体对项目成本内控机制的实施作了探讨,从而更好的提高企业效益,增强企业市场竞争力。     

Direct Interband Light Absorption in Strongly Prolated Ellipsoidal Quantum Dots’ Ensemble

Within the framework of adiabatic approximation, the energy levels and direct interband light absorption in a strongly prolated ellipsoidal quantum dot are studied. Analytical expressions for the particle energy spectrum and absorption threshold frequencies in three regimes of quantization are obtained. Selection rules for quantum transitions are revealed. Absorption edge and absorption coefficient for three regimes of size quantization (SQ) are also considered. To facilitate the comparison of obtained results with the probable experimental data, size dispersion distribution of growing quantum dots by the small semiaxe in the regimes of strong and weak SQ by two experimentally realizing distribution functions have been taken into account. Distribution functions of Lifshits–Slezov and Gaussian have been considered.     

Temperature and gas composition dependence of internal oxidation kinetics of an Fe?10%Cr alloy in water vapour containing environments

Recently it was proposed, that the hampered formation of external protective chromia scales on FeCr‐alloys in water vapour containing, low‐pO₂ gases is correlated with enhanced internal oxidation of chromium. In the present study the internal oxidation kinetics of Fe? 10Cr (in mass%) during isothermal oxidation in Ar? H₂? H₂O mixtures at temperatures in the range 800–1050 °C has been investigated. It was found that the tendency for Cr to become internally oxidized decreased with decreasing temperature. At the higher test temperatures the internal oxide precipitates consisted of Fe/Cr‐spinel. With decreasing temperature the precipitates near the oxidation front gradually exhibited increasing amounts of chromia. At 900 °C the oxidation morphology in the Ar? H₂ base gas mixture changed from exclusive internal oxidation of Cr at a water vapour content of 2% towards a combined internal Cr oxidation and external Fe‐oxide formation at higher water vapour partial pressures.     

两个自旋为1/2粒子在纠缠量子系统中的Berry几何相位

研究了两个自旋为1/2的粒子在自旋相互作用情况下的Berry几何相位纠缠依赖，分别计算了两个自旋为1/2的纠缠粒子之间在存在自旋相互作用和无相互作用下的Berry几何相位，并得到在纠缠消失时几何相位的计算表达式.而且我们还讨论了两个粒子中只有一个粒子受到外磁场作用时的几何相位.结果发现其几何相位并不等于单个粒子在受到外磁场作用时的几何相位，而是与影响自旋纠缠强度作用的 有关,同时还得到了几何相位依赖于纠缠的的普遍公式.