The tube failures took place frequently in the superheater of 2x600MW units in a power plant. According to the condition of tube failures, the mechanical property and microstructure on running and failed tubes were te...The tube failures took place frequently in the superheater of 2x600MW units in a power plant. According to the condition of tube failures, the mechanical property and microstructure on running and failed tubes were tested and evaluated. The chemical composition and structure phase of inner oxide scale and deposit inside of the tubes were examined.The fractured surfaces of failed tube samples were observed. And the material examination was performed for original tube steels SA213-T91 and SA213-T22. The results show that raw materials of SA213-T91 and SA213-T22 tube in superheater are qualified. Besides, the characteristics of the SA213-T91 and SA213-T22 tube failure are typical short-term overheated rupture. The rupture temperature is located between two phase Ac1 ～ Ac3 of the two steels. It is recognized that putting SA213-T22 tubes in operation under the condition of long-term over heating causes the rupture of SA213-T91 and SA213-T22.展开更多
The concentrations of Fe, Mn, Al, Zn, Pb, Ni, Cr, and As were measured in soils and leaves from 21 plant species growing on hills near the Beijing Steel Factory(BSF) and 17 plant species in the Beijing Botanical Garde...The concentrations of Fe, Mn, Al, Zn, Pb, Ni, Cr, and As were measured in soils and leaves from 21 plant species growing on hills near the Beijing Steel Factory(BSF) and 17 plant species in the Beijing Botanical Garden(BBG). The results showed that soils from BSF were Zn contaminated according to the threshold of natural background of China. There was a metal contamination of the soils by Ni, and Cr in BSF comparing with those in BBG. The comparison between concentrations of metals in leaves from both sites indicated that, in general, accumulation of metals in the leaves of the same species was significantly different between the two sites. Even within the same locality each species accumulation of metals was significantly variable. The study aimed to screen landscape plants for the capacity to clean-up toxic metals in soils, and developed an overall metal accumulation index(MAI) for leaves and then categorized the MAI that can be applied broadly in the selection of species in polluted areas. To do this, the spectrum of MAI values were divided into four classes: strongly accumulated(SA or grade I), moderately accumulated(MA or grade II), intermediately accumulated(IA or grade III), and weakly accumulated(WA or grade IV). The results showed that elemental association between Fe, Al, Ni, and As was generally highly correlated with each other in the sampling sites. This may suggest their common biochemical characteristics. Generally, those species containing strong and moderate accumulation in both sites are considered including Vitex negundo, Broussonetia papyrifera, Ulmus pumila, and Rubia cordifolia. At BSF and other industrial sites with a similar ecosystem, strong and moderate accumulation species include Sophora japonica, Ampelopsis aconitifolia var. glabra, Platycladus orientalis, Wikstroemia chamaedaphne, Cleistogenes squarrosa, Grewia biloba, and in BBG, in addition Setaria viridis, Cotinus coggygria, Lespedeza floribunda, Rhamnus parvifolia, Lespedeza tomentosa.展开更多
Invited by Mr. Bao Tianren — President of IATEFL China,President and Editor-in-chief of English Coaching Paper, President of Tonghua Teachers College, Mr. Evan Frendo, Secretary of IATEFL(International Association of...Invited by Mr. Bao Tianren — President of IATEFL China,President and Editor-in-chief of English Coaching Paper, President of Tonghua Teachers College, Mr. Evan Frendo, Secretary of IATEFL(International Association of Teaching English as a Foreign Language ) .which is located in England, paid a friendly visit to the ECP headquarters and the ECP Beijing Research & Development Centre from December 19 to December 22, 2004.展开更多
This was .Mr. Evan Frendo's first visit to China. He showed great interest in China, not only in the new buildings in Beijing and the fantastic Chinese cuisine, but the ECP Beijing Research & Development Centr...This was .Mr. Evan Frendo's first visit to China. He showed great interest in China, not only in the new buildings in Beijing and the fantastic Chinese cuisine, but the ECP Beijing Research & Development Centre in Xiyuan Hotel in Beijing. He had a detailed discussion about the International English Olympics (IEO) with Mr. Bao Tianren in Beijing.展开更多
Invited by Mr. Bao Tianren——President of IATEFL China,President and Editor-in-chief of English Coaching Paper, President of Tonghua Teachers College, Mr. Evan Frendo, Secretary of IATEFL International Association of...Invited by Mr. Bao Tianren——President of IATEFL China,President and Editor-in-chief of English Coaching Paper, President of Tonghua Teachers College, Mr. Evan Frendo, Secretary of IATEFL International Association of Teaching English as a Foreign Language) ,which is located in England, paid a friendly visit to the ECP headquarters and the ECP Beijing Research & Development Centre from December 19 to December 22, 2004.展开更多
文摘The tube failures took place frequently in the superheater of 2x600MW units in a power plant. According to the condition of tube failures, the mechanical property and microstructure on running and failed tubes were tested and evaluated. The chemical composition and structure phase of inner oxide scale and deposit inside of the tubes were examined.The fractured surfaces of failed tube samples were observed. And the material examination was performed for original tube steels SA213-T91 and SA213-T22. The results show that raw materials of SA213-T91 and SA213-T22 tube in superheater are qualified. Besides, the characteristics of the SA213-T91 and SA213-T22 tube failure are typical short-term overheated rupture. The rupture temperature is located between two phase Ac1 ～ Ac3 of the two steels. It is recognized that putting SA213-T22 tubes in operation under the condition of long-term over heating causes the rupture of SA213-T91 and SA213-T22.
文摘The concentrations of Fe, Mn, Al, Zn, Pb, Ni, Cr, and As were measured in soils and leaves from 21 plant species growing on hills near the Beijing Steel Factory(BSF) and 17 plant species in the Beijing Botanical Garden(BBG). The results showed that soils from BSF were Zn contaminated according to the threshold of natural background of China. There was a metal contamination of the soils by Ni, and Cr in BSF comparing with those in BBG. The comparison between concentrations of metals in leaves from both sites indicated that, in general, accumulation of metals in the leaves of the same species was significantly different between the two sites. Even within the same locality each species accumulation of metals was significantly variable. The study aimed to screen landscape plants for the capacity to clean-up toxic metals in soils, and developed an overall metal accumulation index(MAI) for leaves and then categorized the MAI that can be applied broadly in the selection of species in polluted areas. To do this, the spectrum of MAI values were divided into four classes: strongly accumulated(SA or grade I), moderately accumulated(MA or grade II), intermediately accumulated(IA or grade III), and weakly accumulated(WA or grade IV). The results showed that elemental association between Fe, Al, Ni, and As was generally highly correlated with each other in the sampling sites. This may suggest their common biochemical characteristics. Generally, those species containing strong and moderate accumulation in both sites are considered including Vitex negundo, Broussonetia papyrifera, Ulmus pumila, and Rubia cordifolia. At BSF and other industrial sites with a similar ecosystem, strong and moderate accumulation species include Sophora japonica, Ampelopsis aconitifolia var. glabra, Platycladus orientalis, Wikstroemia chamaedaphne, Cleistogenes squarrosa, Grewia biloba, and in BBG, in addition Setaria viridis, Cotinus coggygria, Lespedeza floribunda, Rhamnus parvifolia, Lespedeza tomentosa.
文摘Invited by Mr. Bao Tianren — President of IATEFL China,President and Editor-in-chief of English Coaching Paper, President of Tonghua Teachers College, Mr. Evan Frendo, Secretary of IATEFL(International Association of Teaching English as a Foreign Language ) .which is located in England, paid a friendly visit to the ECP headquarters and the ECP Beijing Research & Development Centre from December 19 to December 22, 2004.
文摘This was .Mr. Evan Frendo's first visit to China. He showed great interest in China, not only in the new buildings in Beijing and the fantastic Chinese cuisine, but the ECP Beijing Research & Development Centre in Xiyuan Hotel in Beijing. He had a detailed discussion about the International English Olympics (IEO) with Mr. Bao Tianren in Beijing.
文摘Invited by Mr. Bao Tianren——President of IATEFL China,President and Editor-in-chief of English Coaching Paper, President of Tonghua Teachers College, Mr. Evan Frendo, Secretary of IATEFL International Association of Teaching English as a Foreign Language) ,which is located in England, paid a friendly visit to the ECP headquarters and the ECP Beijing Research & Development Centre from December 19 to December 22, 2004.
