通过激光熔覆技术应用于燃气轮机空压机轮毂修复进行熔覆焊接试验,研究了熔覆材料和熔覆焊接后试样的断口特征和拉伸力学性能,并进行对比分析.采用DLF207作为焊接材料具有较好的熔覆性,激光熔覆技术修复的缺陷榫齿可大大缩短了检修时间,但存在修复后焊缝强度偏低风险,只能作为一种临时修复办法.

凝汽器真空系统对于电厂运行非常重要,直接影响电厂的经济性和系统运行的稳定性.夏季高温季节,循环冷却水系统运行压力较大,冷却能力受到一定制约,导致真空泵工作液温度长期超温运行,从而影响真空泵的抽吸能力和汽机真空.研究了真空泵工作液温度对汽轮机真空和发电负荷的影响,指导完成了冷却系统的优化改造,并对改造效果进行了试验评估,取得了较好的效果.

Damaged leaf spring in the spray type desuperheater of a 150t/h gas-fired boiler at Lianyuan Steel blocked the two steam exits, causing excessive pressure difference between the drum and superheater. The causes of the problem were analyzed, treatment mea-sures were provided and experience in solving such problems was also summarized.

Hole by hole blasting is a new technique,which developed in the near several years and used by a lot of large open-pit mine.In this paper,based on the introduce of the basic principle,design method and its good blasting results in Huangshan Limestone Mine about hole by hole blasting technique are introduced.

Calvatia geigantea polysaccharide CGP was extracted by hot water,precipitated by ethanol,and deproteinized by Sevag method.The CGPⅠ-1,a main constituent of CGP,was obtained by DEAE-sepharose and Sephacryl S-300HR gel-chromatography.The acid hydrolyzed product and GC-MS analysis of the CGPⅠ-1 showed that CGPⅠ-1 is composed of Gal,Glc,Man and so on.Gal,Glc and Man in a molar ratio of 3.9∶11.28∶1.22.IR analysis,partial hydrolysis with acid,periodate oxidation,Smith degradation,and 1H NMR,13C NMR analysis revealed that the main chain of CGPⅠ-1 is mainly made up of Man and Glc.The side chain or terminal residues is composed of β-Gal(1→4),β-Glc(1→6),α-Glc(1→4).There was amide group in CGPⅠ-1.The molecular structure of the CGPⅠ-1 at different concentrations was observed with atomic force microscopy(AFM).The CGPⅠ-1 molecule had a linear backbone with branches.The net work structure of CGPⅠ-1 was formed through entanglement between the molecules of the polysaccharide.

OBJECTIVE To explore the methods for purification of polysaccharides from Calvatia gigantea,and investigate the characteristics of the polysaccharides.METHODS Polysaccharides form Calvatia gigantea were separated and purified by hot water extraction,ethanol precipitation,and fractionation by ionexchange chromatography on DEAE-sepharose fast flow and Sephacryl S-300 HR chromatography.Sephacryl S-300 HR chromatography,agarose gel electrophoresis,SDS-PAGE,UV spectrum were used to identify the homogenicity of the polysaccharides.The apparent average molecular weight was identified by Sephacryl S-300 HR chromatography.The component of the polysaccharides were identified by GC-MS.The content of uronic acid was identified by carbazole-sulphuric acid analysis.The structural characterizations of the polysaccharides were confirmed by NaIO4 oxidation,Smith degradation and IR.RESULTS Three water-soluble polysaccharides CGP-I,CGP-II and CGP-III were obtained from Calvatia gigantea.Three fractions were shown to be homogeneous by Sephacryl S-300 HR chromatography,agarose gel electrophoresis,SDS-PAGE,and UV spectrum.The apparent average molecular weight of CGP-I,CGP-II and CGP-III were estimated to be 9.12×104 Da,18.6×104 Da and 15.6×104 Da,respectively.The component of polysaccharides:mannose,glucose and galactose were found to be in the molar radio of 1.22:11.28:3.92 in CGP-Ⅰ,1.74:26.45:0.36 in CGP-Ⅱ,1.06:9.9:3.29 in CGP-Ⅲ,and an unknown monosaccharide was found.The content of uronic acid in CGP-Ⅱ,CGP-Ⅲ was 17.2 % and 20.5%,respectively,and there was no uronic acid in CGP-Ⅰ.The results of structural characterization showed that they were all branching chain polysaccharide with more 1→4 linking,fewer 1→6 linking.CGP-Ⅰwas neutral polysaccharide which was mainly composed of pyranose and had both β-and α-epimer,CGP-Ⅱ,CGP-Ⅲ were acidic polysaccharides which were composed of pyranose and had β-epimer.CONCLUSION The preliminary property and structural characterization of the polysaccharides purified from calvatia gigantea were investigated.

It is no doubt that Policy circumstances have effect to strategy.But the effect didn't be validated in study before.The author analyzed existing theory and practice,and then exploited the framework of strategic adjustment based on the changing of policy circumstances and put forward four hypotheses.The author validated the effect system and extent between policy circumstances and corporation strategy utilizing the data collected from many corporations and found out that corporation resource had cushion effect in this effect system.