AP1000核电汽轮机转子疲劳断裂分析

针对核电汽轮机转子疲劳断裂进行分析,分别对高周疲劳以及低周疲劳引起的转子断裂进行分析。分析表明：除了破坏性超速原因,无论是低周疲劳还是高周疲劳均不会导致低压整锻转子产生断裂。     

LNG储罐区防液堤的设计探讨

结合工程实例,探讨了LNG储罐区防液堤设计中有效容积和形状的确定、混凝土材料的选择和配置.针对提高防液堤的抗低温和耐高温性能,提出了建议.     

煤化工工艺技术发展趋势浅析

本文主要针对目前煤中低温干馏的工艺技术现状,从节能降耗、资源充分利用角度探讨洁净型煤化工工艺技术的发展趋势,对煤的中低温热解技术的选择具有重要意义。     

Exposure of workers to extremely low frequency magnetic fields during the temperature-rise test of electrotechnical equipment

In this paper, extremely low frequency (ELF) magnetic fields (MFs) were measured during the temperature-rise test of various electrotechnical equipment. The number of workers subjected to magnetic fields from the temperature-rise test is small; however, the exposure can be significant as the testing currents can be in the order of hundreds amperes. The resultant magnetic field during testing can exceed the ICNIRP limits for occupational exposure. The magnetic field exposure was recorded and statistical measures were extracted for three electrotechnical apparatus. It was found that the Time-Weighted Average exposure per unit current can reach 0.0598 μT/A. Additionally, in order to mitigate the exposure, a rule of thumb regarding safety distances has been proposed. It is shown that the use of this rule of thumb can reduce the magnetic field exposure.     

用五点井网生产数据计算相对渗透率的简易算法

当面对五点法井网布井不规则和强非均质性时,在没有取心数据或取心数据不全面的情况下,仅根据生产数据计算相对渗透率的难度很大,为此提出一种利用生产数据近似计算复杂地层条件下相对渗透率的简易算法,并通过五点法井网模型水驱实验及CMG模型拟合来验证相对渗透率计算方法的准确性。结果表明该方法计算的相对渗透率比较接近实际情况,用于数值模拟能提高历史拟合的速度。与其他方法进行对比,具有更加简单的优点。     

Tensile flow behavior of ultra low carbon,low carbon and micro alloyed steel sheets for auto application under low to intermediate strain rate

This paper is concerned with tensile characteristics of auto grade low carbon, ultra low carbon and micro alloyed steel sheets under low to intermediate strain rates ranging from 0.0007 to 250 s⁻¹. Experimental investigation reveals two important aspects of these steels under intermediate strain rate deformation. Firstly, the yield stress increases with strain rate in all these steels. Of course yield stress increment is higher for low carbon and ultra low carbon steel sheets. Secondly, the strain hardening rate drastically decreases with strain rate for low carbon and ultra low carbon steel sheets, whereas it remains steady for micro alloyed steel sheets. Based on these observations, a constitutive model has been proposed which predicts the strain rate sensitive flow behavior of all these grades within the strain rate range of automotive crash event.     

Design of 60GHz RF Transceiver in CMOS:Challenges and Recent Advances

With more than 40 years Moore scaling, the speed of CMOS transistors is around 100 GHz. Such fact makes it possible to realize mm-wave circuits in CMOS. However, with the target of achieving broadband and power-efficient operation, 60 GHz CMOS RF transceiver faces severe challenges. After reviewing the technology issues, regarding the 60 GHz applications, this paper discusses design challenges both from the system and the building block levels, and also presents some simulated or measured circuits results.     

Robust low bit‐rate transmission using multiple‐PBDBS (MPBDBS) approach

Abstract

Recently, Gao and Tu presented an efficient algorithm for robust low bit‐rate video transmission by using a partial backward decodable bit stream (PBDBS) approach. In this paper, we first present a multiple‐PBDBS (MPBDBS) approach to improve on the previous PBDBS approach. Next a mathematical theory is provided to minimize the error propagation length in each group of blocks (GOB). Further, a novel MPBDBS‐based algorithm is presented for robust video transmission. Experimental results demonstrate that our proposed MPBDBS‐based algorithm has better image quality when compared to the previous PBDBS‐based algorithm, but has some bit‐rate and execution‐time degradation. In our experiments, both single and two‐bit error models are investigated.     

低温敏化乳化炸药在低温天气下保持高性能的探讨

为了有效解决低温敏化乳化炸药在低温天气下产品质量不稳定的现状,分别从工艺参数的调整、工装条件的改善、贮存条件的改善三方面入手进行改进,使低温敏化乳化炸药在低温天气下的产品质量稳定性得到明显改善。结果表明,通过对生产线的一系列改进,在低温天气下产品质量得到明显提升,改进效果明显。