宝鸡热电公司50MW汽轮机调门裂纹的分析处理

详细介绍宝鸡热电公司50MW汽轮机进汽调门与阀座角焊缝裂纹的原因分析,处理过程以及工艺,对长时间运行,老化材质的补焊做以初步总结。

高钒高速钢中MC碳化物的定量分析方法

采用扫描电子显微镜+金相分析软件相结合的试验方法,对高钒高速钢中的MC碳化物进行了定量分析。结果表明,通过黑白反转、彩色灰度化及图像分割操作,可准确测量任一类型碳化物的百分含量,且所有碳化物体积之和与未进行图像提取操作的碳化物体积一致。该实验方法可以准确检测高钒高速钢中MC碳化物的面积分数,以及其颗粒大小、个数等,能够满足定量分析的需求。

基于全相FFT的电力变压器噪声衰减模型

分析变压器噪声信号的频域特性和衰减模型,有利于变电站有源噪声控制技术的研究。对某变压器噪声信号进行全相FFT频谱分析,得到其频域特性曲线。由频谱图可以看出,该变压器噪声以100 Hz为基频,并在基频处噪声声压级达到峰值。首先利用全相FFT谱分析法处理各参考点噪声信号,得到倍频带声压级。再结合变电站各参数,建立声衰减模型,即可计算预测点声衰减量并合成其A声级,进而绘制出变电站噪声A声级及100 Hz声压级分布图。结合全相FFT的噪声衰减模型可以准确地计算出变电站的噪声分布,直观地评价变压器噪声对周边环境的影响。

Spatio-temporal Analysis of Urban Spatial Interaction in Globalizing China—A Case Study of Beijing-Shanghai Corridor

This paper aims to explore urban geography with a new perspective. Endowed with the urban geography connotations, an improved data field model is employed to integrate temporal dimension into spatial process of cities in a typical region in this article. Taking the Beijing-Shanghai Corridor including 18 cities as an example, the authors chose the city centricity index (CCI) and the spatial data field model to analyze the evolution process and features of sub-region and urban spatial interaction in this corridor based on the data of 1991, 1996 and 2002. Through the analy- sis, we found that: 1) with the improvement of the urbanization level and the development of urban economy, the cit- ies’ CCI grew, the urban spatial radiative potential enhanced and the radiative range expanded gradually, which reflects the urban spatial interaction’s intensity has been increasing greatly; 2) although the spatial interaction intensity among the cities and sub-regions in the Beijing-Shanghai Corridor was growing constantly, the gap of the spatial interaction strength among different cities and sub-regions was widening, and the spatial division between the developed areas and the less developed areas was obvious; and 3) the intensity of the spatial interaction of Beijing, Shanghai and their urban agglomerations was far greater than that in small cities of other parts of the corridor, and it may have a strong drive force on the choice of spatial location of the economic activities.

Analysis on China＇s Economic Transformation and Its Relevance to Global Economy

China＇s current economic transformation has its historical reasons and its urgent need of change. With over 30 years of reform and opening-up, China＇s economy experienced high-speed growth for a sustained period, but China is still confronted with many obstacles which call for immediate attention, such as shortage of resources, deterioration of the environment, structural imbalance, and intensified social conflict. If these problems persist, an ominous future would not be avoided unless an economic transformation was in effect. As China＇s economic power and international influence increase, its economic transformation will significantly impact not only its domestic economy, but also the world economy. This article analyzes the transformation of China＇s economy from an international perspective, particularly focuses on the relationship between China＇s transformation and the economies of most developed countries （e.g., United States and EU） by comparing data and analyzing impacts caused by each other. At the end, the article will provide some suggestions for further research.

Isolation of Immune-Relating 185/333-1 Gene from Sea Urchin(Strongylocentrotus intermedius) and Its Expression Analysis

The 185/333 gene family involved in the immune response of sea urchin.One 185/333 c DNA was isolated from Strongylocentrotus intermedius,and named as Si185/333-1.Its full-length c DNA was 1246 bp in length with a 906 bp open reading frame encoding a protein of 301 aa.The molecular weight of the deduced protein was approximately 33.1 k D with an estimated PI of p H 6.26.Si185/333-1 had high identities(70%–86%) to most of Sp185/333.An extraordinary identity of 92% was found between Si185/333-1 and Sp185/333 C5 alpha(ABR22474).Moderate identities(63%–64%) were displayed between Si185/333-1 and He185/333.Si185/333-1 had similar structure to Sp185/333.A signal-peptide,a gly-rich region and a his-rich region were found in its secondary structure.RGD motif was found in gly-rich region at position 116–118aa.There was no transmembrane region in Si185/333-1.The element pattern of Si185/333-1 is different from any available pattern that identified in Sp185/333.Si185/333-1 clustered together with pattern C Sp185/333 in phylogenetic tree.The Si185/333-1 m RNA could be detected in tissues including peristomial membrane,coelomocytes,muscle of Aristotles lantern,gut and tube feet,with the highest expression level detected in peristomial membrane and a relatively low expression in ovary and testis.The temporal expression of Si185/333-1 in peristomial membrane and coelomocytes were up-regulated after bacterial,β-D-glucan and ds RNA challenges,reaching the maximum at 12 h post-stimulation.The up-regulation was more obvious in coelomocytes,and bacterial challenge triggered the highest response.These results proved that 185/333-1 gene was involved in the immune defense of S.intermedius,while more studies were necessary for its function in S.intermedius immunity.

Preserving privacy information flow security in composite service evolution

After a composite service is deployed, user privacy requirements and trust levels of component services are subject to variation. When the changes occur, it is critical to preserve privacy information flow security. We propose an approach to preserve privacy information flow security in composite service evolution. First, a privacy data item dependency analysis method based on a Petri net model is presented. Then the set of privacy data items collected by each component service is derived through a privacy data item dependency graph, and the security scope of each component service is calculated. Finally, the evolution operations that preserve privacy information flow security are defined. By applying these evolution operations, the re-verification process is avoided and the evolution efficiency is improved. To illustrate the effectiveness of our approach, a case study is presented. The experimental results indicate that our approach has high evolution efficiency and can greatly reduce the cost of evolution compared with re-verifying the entire composite service.

Spatial Linear Combination Forecasting Model and Its Application

The accuracy of spatial forecasting is close relation to the selection of spatial forecasting model. Each model from special aspects using special spatial data has its own advantage or disadvantage. A more accurate spatial forecasting model can be obtained by a linear combination of some models. In this study, first-order spatial autoregressive （SAR（1）） model, Kriging algorithm interpolation （KAI） model and back-propagation neural network （BPNN） model are established by using cross-section data or time series data. A spatial linear combination forecasting （SLCF） model is obtained by the combination models mentioned above. An empirical research by these models is carried out with forecasting some areas＇ GDP per capita in Fujian, 2003. It is found that the best one is the SLCF model.