Peroxodiphosphate anion （a powerful oxidant） can be formed in a special water-based cleaning agent through an electrochemical reaction on boron-doped diamond electrodes. This electrochemical reaction was applied dur...Peroxodiphosphate anion （a powerful oxidant） can be formed in a special water-based cleaning agent through an electrochemical reaction on boron-doped diamond electrodes. This electrochemical reaction was applied during the oxidation,decomposition, and removal of organic contaminations on a silicon wafer surface, and it was used as the first step in the diamond electrochemical cleaning technique （DECT）. The cleaning effects of DECT were compared with the RCA cleaning technique, including the silicon surface chemical composition that was observed with X-ray photoelectron spectroscopy and the morphology observed with atomic force microscopy. The measurement results show that the silicon surface cleaned by DECT has slightly less organic residue and lower micro-roughness,so the new technique is more effective than the RCA cleaning technique.展开更多
The effects of boride coating on the bioactivity, antibacterial activity, and electrochemical behavior of commercially pure titanium(CP-Ti) in phosphate buffer solution(PBS) with bovine serum albumin(BSA) were studied...The effects of boride coating on the bioactivity, antibacterial activity, and electrochemical behavior of commercially pure titanium(CP-Ti) in phosphate buffer solution(PBS) with bovine serum albumin(BSA) were studied. The grazing incidence X-ray diffraction(GIXRD) pattern confirmed the formation of a Ti B/Ti B2 coating via boriding process. Scanning electron microscopy(SEM) observation indicated that the Ti B2 cross-linked particles covered the Ti B whiskers. Water contact angle measurements revealed that boriding led to the formation of a surface with intermediate water affinity. Potentiodynamic polarization(PDP) assays demonstrated that the Ti B/Ti B2 coating had acceptable passivation behavior in BSA-containing PBS. Electrochemical impedance spectroscopy(EIS) measurements revealed that the passivation behavior of the CP-Ti and the borided samples was improved by increasing exposure time. Based on the Mott-Schottky(M-S) tests, it was realized that the charge carriers of passive films of both samples decreased with increasing exposure time in BSA-containing PBS. The bioactivity test results in a simulated body fluid showed that the Ti B/Ti B2 coating switched the CP-Ti from bioinert to bioactive material. Finally, the antibacterial activity test of the Ti B/Ti B2 coating against Escherichia coli and Staphylococcus aureus indicated 99% antibacterial activity.展开更多
Engineering education is an important issue in engineering practice, and engineering practice and characteristics can be seen through examining the history of early Chinese engineering education. During the period ran...Engineering education is an important issue in engineering practice, and engineering practice and characteristics can be seen through examining the history of early Chinese engineering education. During the period ranging from the 1860s to the middle of the 1890s, the westernization group set up a series of modern industrial and mining enterprises for military and civil use, making the implementation of modern engineering education become possible and necessary. Thanks to their efforts, many schools and old-style private schools for teaching knowledge about western science and technology and training senior engineering managements and talents were gradually founded in China. These modern education organizations are the source and beginning of Chinese engineering education, which is also the origin of modernization of Chinese engineering education. This article takes Fuzhou Shipping School for case studies, using a cultural anthropology approach to examine the overall status, basic characteristics, and impact evaluation of engineering education during the Westernization Movement in China. It reiterates the idea of that ＂engineering education should be returned to engineering practice,＂ and tries to explain the framework of the development of engineering education in China. Through conducting research, we find that the development of engineering education in modem China generally has the basic resources for realization of internationalization through ＂westernization＂ and localization through traditional culture and education and the general characteristics of diversification of social influence. During the development process, it has accumulated valuable experience for timely reform and gradual improvement of modernization： attaching importance to culture and cultivating qualified technical personnel; strictly requiring and building high-level schools and specialties; learning the advanced knowledge and bravely utilizing foreign educational resources; setting pragmatic and highly pertinent disciplines and specialties. It also left the society with thought-provoking lessons, namely, the lagging industrial production and social instability made the development severely restricted and obstructed; the unreasonable development layout resulted in the intensified imbalanced development in different regions; the bureaucracy nature imposed serious impact on efficiency and effectiveness of education; the negligence of innovation made the great-leap-forward development failed, etc.展开更多
Coal is still a major source of energy, also a major source of SO_2, NOx and CO_2 emission though. Removal of SO_2 and NOx doubled the cost of power generation, and capture of CO_2 is equivalent to double the market p...Coal is still a major source of energy, also a major source of SO_2, NOx and CO_2 emission though. Removal of SO_2 and NOx doubled the cost of power generation, and capture of CO_2 is equivalent to double the market price of power coal. The GCP （green coal power） is the power generated in coal-combustion with zero emission. The author indicates that it is possible to make coal-fired power plants emission free based on thermodynamic analysis and purposely designed experiments using SFG （simulated flue gases）. It is concluded in the study that all SO_2 and NOx in the post-combustion flue gas are reduced to inoffensive substances at temperature lower than 750 ℃ when contacting carbon and elemental sulfur is separated in succeeded cooling of flue gas at temperatures 200-400 ℃, and the ultrafine dusts are trapped in condensed water at temperature blow 100 ℃. Based on chemical engineering expertise the author is sure that the cost for removing acid gases is much lower than any clean coal technologies known to today. Instead of capture, the remained CO_2 is converted to CO in the second time contact with carbon at 900-950 ℃. CO is the raw material of chemical synthesis and, thus, CO_2 is stored in chemical products such as methanol, fertilizer, plastics, etc. The simple and low-cost processing allows GCP utilized in practice easily.展开更多
文摘Peroxodiphosphate anion （a powerful oxidant） can be formed in a special water-based cleaning agent through an electrochemical reaction on boron-doped diamond electrodes. This electrochemical reaction was applied during the oxidation,decomposition, and removal of organic contaminations on a silicon wafer surface, and it was used as the first step in the diamond electrochemical cleaning technique （DECT）. The cleaning effects of DECT were compared with the RCA cleaning technique, including the silicon surface chemical composition that was observed with X-ray photoelectron spectroscopy and the morphology observed with atomic force microscopy. The measurement results show that the silicon surface cleaned by DECT has slightly less organic residue and lower micro-roughness,so the new technique is more effective than the RCA cleaning technique.
基金Iran National Science Foundation(INSF)for supporting the research under project No.95841122.
文摘The effects of boride coating on the bioactivity, antibacterial activity, and electrochemical behavior of commercially pure titanium(CP-Ti) in phosphate buffer solution(PBS) with bovine serum albumin(BSA) were studied. The grazing incidence X-ray diffraction(GIXRD) pattern confirmed the formation of a Ti B/Ti B2 coating via boriding process. Scanning electron microscopy(SEM) observation indicated that the Ti B2 cross-linked particles covered the Ti B whiskers. Water contact angle measurements revealed that boriding led to the formation of a surface with intermediate water affinity. Potentiodynamic polarization(PDP) assays demonstrated that the Ti B/Ti B2 coating had acceptable passivation behavior in BSA-containing PBS. Electrochemical impedance spectroscopy(EIS) measurements revealed that the passivation behavior of the CP-Ti and the borided samples was improved by increasing exposure time. Based on the Mott-Schottky(M-S) tests, it was realized that the charge carriers of passive films of both samples decreased with increasing exposure time in BSA-containing PBS. The bioactivity test results in a simulated body fluid showed that the Ti B/Ti B2 coating switched the CP-Ti from bioinert to bioactive material. Finally, the antibacterial activity test of the Ti B/Ti B2 coating against Escherichia coli and Staphylococcus aureus indicated 99% antibacterial activity.
文摘Engineering education is an important issue in engineering practice, and engineering practice and characteristics can be seen through examining the history of early Chinese engineering education. During the period ranging from the 1860s to the middle of the 1890s, the westernization group set up a series of modern industrial and mining enterprises for military and civil use, making the implementation of modern engineering education become possible and necessary. Thanks to their efforts, many schools and old-style private schools for teaching knowledge about western science and technology and training senior engineering managements and talents were gradually founded in China. These modern education organizations are the source and beginning of Chinese engineering education, which is also the origin of modernization of Chinese engineering education. This article takes Fuzhou Shipping School for case studies, using a cultural anthropology approach to examine the overall status, basic characteristics, and impact evaluation of engineering education during the Westernization Movement in China. It reiterates the idea of that ＂engineering education should be returned to engineering practice,＂ and tries to explain the framework of the development of engineering education in China. Through conducting research, we find that the development of engineering education in modem China generally has the basic resources for realization of internationalization through ＂westernization＂ and localization through traditional culture and education and the general characteristics of diversification of social influence. During the development process, it has accumulated valuable experience for timely reform and gradual improvement of modernization： attaching importance to culture and cultivating qualified technical personnel; strictly requiring and building high-level schools and specialties; learning the advanced knowledge and bravely utilizing foreign educational resources; setting pragmatic and highly pertinent disciplines and specialties. It also left the society with thought-provoking lessons, namely, the lagging industrial production and social instability made the development severely restricted and obstructed; the unreasonable development layout resulted in the intensified imbalanced development in different regions; the bureaucracy nature imposed serious impact on efficiency and effectiveness of education; the negligence of innovation made the great-leap-forward development failed, etc.
文摘Coal is still a major source of energy, also a major source of SO_2, NOx and CO_2 emission though. Removal of SO_2 and NOx doubled the cost of power generation, and capture of CO_2 is equivalent to double the market price of power coal. The GCP （green coal power） is the power generated in coal-combustion with zero emission. The author indicates that it is possible to make coal-fired power plants emission free based on thermodynamic analysis and purposely designed experiments using SFG （simulated flue gases）. It is concluded in the study that all SO_2 and NOx in the post-combustion flue gas are reduced to inoffensive substances at temperature lower than 750 ℃ when contacting carbon and elemental sulfur is separated in succeeded cooling of flue gas at temperatures 200-400 ℃, and the ultrafine dusts are trapped in condensed water at temperature blow 100 ℃. Based on chemical engineering expertise the author is sure that the cost for removing acid gases is much lower than any clean coal technologies known to today. Instead of capture, the remained CO_2 is converted to CO in the second time contact with carbon at 900-950 ℃. CO is the raw material of chemical synthesis and, thus, CO_2 is stored in chemical products such as methanol, fertilizer, plastics, etc. The simple and low-cost processing allows GCP utilized in practice easily.
