A kind of ceramic slurry was prepared and sprayed onto the surface of 9Ni steel at room temperature. The coating layer will not only reduce the depth of the formed Ni-enriched entanglement at high temperature but also...A kind of ceramic slurry was prepared and sprayed onto the surface of 9Ni steel at room temperature. The coating layer will not only reduce the depth of the formed Ni-enriched entanglement at high temperature but also have an excellent ability to resist oxidation of the 9Ni steel. Compared to bare specimen, the depths of the entanglement of the coated 9Ni specimen could be successfully reduced by 74.1% and the oxidation loss be decreased by 62.3% by heating at 1 250 ℃ for 60 min. In addition, the coated specimen indicates no trace of oxide pegs. It proves that the coating has outstanding improvement to internal oxidation resistance. Some characterization methods such as metalloscopy, XRD, XPS, SEM and EDX have been used to reveal a possible protective mechanism. The result shows that the coating layer reacts with the iron oxide to form Mg Fe2O4 on the surface of the coated specimen, which could provide a smaller diffusion coefficient rate of Fe ion. The coating with a low cost and easy implementation is promisingly applicable in the slab-reheating process of the 9Ni steel.展开更多
A set of soil collapse prediction and prevention swtem for railway slopes is builtis this paper. Based on the field investisation, Oreen-Ampt model, the quantitytheory and computeraided decision-making sgutem, convere...A set of soil collapse prediction and prevention swtem for railway slopes is builtis this paper. Based on the field investisation, Oreen-Ampt model, the quantitytheory and computeraided decision-making sgutem, convereion tables ofworking rainfall ,grading tables of resistant ability to rainfall, and the warningrairifall levels are made, forming the chief part of a practical computer-aideddecisionmaking system. Usins the system, the danser degree of railway slopescan be predicted, and the reinforcins ensineerins and the flood control workcan also be arranged ratiofially.展开更多
Aims: To screen for the predominant bacteria strains distributed in clean rooms and to analyze their phylogenetic relationships. Methods and Results: The bacteria distributed in air, surfaces and personnel in clean ro...Aims: To screen for the predominant bacteria strains distributed in clean rooms and to analyze their phylogenetic relationships. Methods and Results: The bacteria distributed in air, surfaces and personnel in clean rooms were routinely moni-tored using agar plates. Five isolates frequently isolated from the clean rooms of an aseptic pharmaceutical production workshop were selected based on their colony and cell morphology characteristics. Their physiological and biochemical properties, as well as partial 16S rDNA sequences, were analyzed. Results showed that all the five isolates belong to Gram positive bacteria, of which three were Staphylococcus, one Microbacterium and one Bacillus species. Sensitivity tests for these bacteria isolates to 3 disin-fectants showed that isolate F03 was obtuse, and had low susceptivity to UV irradiation, while isolates F02, F01 and F04 were not sensitive to phenol treatment. Isolates F04, F01 and F05 were resistant to chlorhexidine gluconate. Conclusion: Bacteria widely distributed in clean rooms are mainly a group of Gram positive strains, showing high resistance to selected disinfectants. Sig-nificance and impact of the study: Clean rooms are essential in aseptic pharmaceutical and food production. Screening bacteria isolates and identifying them is part of good manufacturing practices, and will aid in finding a more effective disinfection method.展开更多
基金Funded by the Key Projects in the National Science &Technology Pillar Program in the Twelfth Five-year Plan Period(No.2012BAB08B04)the National Natural Science Foundation of China(No.51202249)
文摘A kind of ceramic slurry was prepared and sprayed onto the surface of 9Ni steel at room temperature. The coating layer will not only reduce the depth of the formed Ni-enriched entanglement at high temperature but also have an excellent ability to resist oxidation of the 9Ni steel. Compared to bare specimen, the depths of the entanglement of the coated 9Ni specimen could be successfully reduced by 74.1% and the oxidation loss be decreased by 62.3% by heating at 1 250 ℃ for 60 min. In addition, the coated specimen indicates no trace of oxide pegs. It proves that the coating has outstanding improvement to internal oxidation resistance. Some characterization methods such as metalloscopy, XRD, XPS, SEM and EDX have been used to reveal a possible protective mechanism. The result shows that the coating layer reacts with the iron oxide to form Mg Fe2O4 on the surface of the coated specimen, which could provide a smaller diffusion coefficient rate of Fe ion. The coating with a low cost and easy implementation is promisingly applicable in the slab-reheating process of the 9Ni steel.
文摘A set of soil collapse prediction and prevention swtem for railway slopes is builtis this paper. Based on the field investisation, Oreen-Ampt model, the quantitytheory and computeraided decision-making sgutem, convereion tables ofworking rainfall ,grading tables of resistant ability to rainfall, and the warningrairifall levels are made, forming the chief part of a practical computer-aideddecisionmaking system. Usins the system, the danser degree of railway slopescan be predicted, and the reinforcins ensineerins and the flood control workcan also be arranged ratiofially.
基金Project (No. 30371703) supported by the National Natural ScienceFoundation of China
文摘Aims: To screen for the predominant bacteria strains distributed in clean rooms and to analyze their phylogenetic relationships. Methods and Results: The bacteria distributed in air, surfaces and personnel in clean rooms were routinely moni-tored using agar plates. Five isolates frequently isolated from the clean rooms of an aseptic pharmaceutical production workshop were selected based on their colony and cell morphology characteristics. Their physiological and biochemical properties, as well as partial 16S rDNA sequences, were analyzed. Results showed that all the five isolates belong to Gram positive bacteria, of which three were Staphylococcus, one Microbacterium and one Bacillus species. Sensitivity tests for these bacteria isolates to 3 disin-fectants showed that isolate F03 was obtuse, and had low susceptivity to UV irradiation, while isolates F02, F01 and F04 were not sensitive to phenol treatment. Isolates F04, F01 and F05 were resistant to chlorhexidine gluconate. Conclusion: Bacteria widely distributed in clean rooms are mainly a group of Gram positive strains, showing high resistance to selected disinfectants. Sig-nificance and impact of the study: Clean rooms are essential in aseptic pharmaceutical and food production. Screening bacteria isolates and identifying them is part of good manufacturing practices, and will aid in finding a more effective disinfection method.
