A new hybrid state estimation based on pseudo‐voltage measurements

This paper presents a new hybrid state estimation method based on the concept of pseudo‐voltage measurements for a power system containing both conventional and synchronizing phasor measurements. Actual measurement data is employed to calculate the magnitude and phase of the pseudo‐voltage. In the proposed formulation, the measurement matrix describing the relations between the measured data and the state variables contains only 0 or 1. Then the state estimation problem is formulated based on the weighted least‐squares criterion, and its solution can be obtained without using iterative procedures. Comparisons with previous hybrid state estimation methods have been performed on IEEE 14‐bus, 57‐bus, and 118‐bus systems. Numerical experimental results indicate that the proposed approach yields solutions of comparable accuracy with other methods but with shorter computation times. Moreover, the proposed method also provides superior results in the presence of bad data. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

包钢高炉长寿风口的研制

文章论述了包钢高炉长寿风口的的设计、研制及工业试验。该风口在高炉上使用后,对炉缸初始煤气流合理分布起到了较好的作用,共使用了250个长寿风口,最高使用寿命达618天。     

影响热轧板带精轧机工作辊寿命的因素分析

介绍了鞍钢热轧板带精轧机工作辊工作状况,对影响轧辊使用寿命的主要因素进行了分析,提出了具体改进措施,如在轧制过程中确保充足的冷却水量、投入热轧油、选择适宜的轧辊存放温度等。实施后减少了轧辊磨损量和轧辊剥落,降低了轧辊断裂出现几率,提高了工作辊使用寿命。     

干熄焦炉耐材的损坏与修复

分析武钢集团鄂城钢铁公司焦化厂干熄焦炉耐材损坏的原因,通过采取相应的防护修复措施,有效地延长了干熄焦炉的使用寿命。     

新型钢包浇注料的研制与应用

以特级高铝矾土、电熔镁砂、棕刚玉、电熔镁铝尖晶石为主要原料,研究了Secar-71水泥、硅灰、SM高效减水剂对新型钢包浇注料性能的影响。结果表明,Secar-71水泥、硅灰、SM高效减水剂外加量分别为3％、4％、0．25％时浇注料的强度高,硬化适中,流动性好。通过工业试验,钢包使用寿命最高达到118炉,平均寿命105炉,比原来的钢包浇注料（平均83炉）提高了22炉,增幅达到26．5％。现已批量投入使用,替代了原来的浇注料。     

随机载荷作用下的疲劳寿命计算

In two-dimensional fatigue load spectrum,the range and mean of random load are regarded as two random variables which could be obtained by rainflow method.Joint probability density function of the two variables is built up on the statistical analysis of load history.Applying constant amplitude median Sa-Sm-N surface function,a fatigue life prediction method of two-dimensional load spectrum is presented based on Miner’s rule.In the last part,an example is presented to demonstrate the application of the prediction method,and it shows that the two-dimensional fatigue life prediction method is practicable in fatigue life analysis for engineering structures.     

自蔓延高温合成Ti3AlC2陶瓷材料

以Ti、Al、C、TiC粉末为原料,研究掺杂Si及Al含量对自蔓延高温合成Ti3AlC2的影响,合成材料的X射线衍射仪(XRD)及扫描电子显微镜(SEM)分析结果表明:物质的量比n(Ti)∶n(Al)∶n(C)∶n(TiC)∶n(Si)=2∶1.2∶1∶0.9∶0.1的原始混合粉末,经50 MPa压力压制的压坯在空气中...     

Forensic applications of C at CIRCE

The decreasing trend of the radiocarbon pulse produced during the atmospheric tests of nuclear weapons (bomb-carbon) coupled with high sensitivity accelerator mass spectrometry (AMS) measurements, drastically increased the precision of radiocarbon age determinations since the second part of the sixties, allowing the application of radiocarbon AMS to a wide range of studies previously not directly involving conventional radiocarbon dating (i.e. food authenticity, forensic, biochemistry). In the framework of authenticity evaluation of artworks, high precision radiocarbon (¹⁴C) AMS measurements (ΔR/R < 0.3%) reduce the conventional uncertainty of the dating to few decades, allowing precise age estimation of materials containing carbon (C). The Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE) during its activity on AMS ¹⁴C dating achieved high precision measurements opening the opportunity to these kinds of applications. This paper presents the main results obtained from radiocarbon measurements on a set of bone samples analyzed for the determination of the post-mortem interval in the framework of an unsolved case investigated by the Rome prosecutor office. The chronological characterization of the wooden support of the “Acerenza portrait” is also presented with the aim to evaluate its age and to further investigate the possibility to attribute this artwork to Leonardo da Vinci.Bomb-¹⁴C dating on the lipid and collagen fractions of bones allows the evaluation of the year of the death of the individuals by means of ad hoc calibration data sheet with the typical few years precision and difference between collagen apparent age and the year of death appeared in agreement with the age of one individual estimated by dating of tooth collagen. Conventional radiocarbon dating on both wood and wood extracted cellulose leads to an estimation of the portrait wood board age (2σ) of 1459-1524 AD (57% relative probability), 1571-1631 AD interval (42% relative probability).and 1559-1563 AD (1% relative probability). These results attribute with the highest relative probability an age comprised within the life span of Leonardo (1452-1519) to the support.     

轧机机架辊损坏原因分析及改造

针对邯钢中板轧机机架辊存在的辊径断裂、辊面粘钢等问题,通过辊子载荷计算及辊面粘钢机理的研究,确定了机架辊损坏的原因。提出机架辊改造方案,辊径由~190mm增加到p220mm,提高了承载能力;改用滚动轴承;改进辊面材料提高辊面的耐磨性和强度。经过多次运行证明,改造后其使用寿命及其它综合性能得到大幅度提升,满足中板线生产的需要。