The composition of products formed from photooxidation of the aromatic hydrocarbon toluene was investigated. The OH-initiated photooxidation experiments were conducted by irradiating toluene/CH3ONO/NO/air mixtures in ...The composition of products formed from photooxidation of the aromatic hydrocarbon toluene was investigated. The OH-initiated photooxidation experiments were conducted by irradiating toluene/CH3ONO/NO/air mixtures in a smog chamber, the gaseous products were detected under the supersonic beam conditions by utilizing vacuum ultraviolet photoionization mass spectrometer using synchrotron radiation in real-time. And an aerosol time-of-flight mass spectrometer was used to provide on-line measurements of the individual secondary organic aerosol particle resulting from irradiating toluene. The experimental results demonstrated that there were some differences between the gaseous products and that of particle-phase, the products of glyoxal, 2-hydroxyl-3-oxo-butanal, nitrotoluene, and methyl-nitrophenol only existed in the particle-phase. However, furane, methylglyoxal, 2-methylfurane, benzaldehyde, cresol, and benzoic acid were the predominant photooxidation products in both the gas phase and particle phase.展开更多
As a matured technique used in many fields,the distributed computer system is still a new management method for the aeronautical electrical power distribution system in our country. In this paper, a novel aircraft ele...As a matured technique used in many fields,the distributed computer system is still a new management method for the aeronautical electrical power distribution system in our country. In this paper, a novel aircraft electrical power distribution system based on the distributed computer system is proposed. The principles, features and structure of the aircraft electrical power distribution system and the distributed computer system named electrical load management system (ELMS) are studied. The ELMS composed of four electrical load management centers (ELMCs) and two power source processors (PSPs) operates in the 1553B buses. Principles of the ELMCs and the PSPs are introduced. With the application of the distributed computer system, the aircraft electrical power distribution system is simple, adaptable and flexible.展开更多
In view of the unclear cause of perfluorocarbons(PFCs)emission in the anode effect stage of aluminum electrolysis,the microscopic formation mechanism of PFCs was studied by density functional theory calculation and X-...In view of the unclear cause of perfluorocarbons(PFCs)emission in the anode effect stage of aluminum electrolysis,the microscopic formation mechanism of PFCs was studied by density functional theory calculation and X-ray photoelectron spectroscopy(XPS).It is found that the discharge of fluorine containing anions([F]−)on carbon anode first causes the substitution of C—H by C—F and further results in the saturation of aromatic C—C bonds,leading to the appearance of—CF_(3)or—C_(2)F_(5)group through six-carbon-ring opening.Elimination of—CF_(3)and—C_(2)F_(5) with F atom could be a likely mechanism of CF_(4) and C_(2)F_(6) formation.XPS results confirm that different types of—CF_(x) group can be formed on anode surface during electrolysis,and the possibility that[F]−discharges continuously at the C edge and finally forms different C—F bonds in quantum mechanical calculation was verified.展开更多
The wastes and the by-products of food industrial technologies are suitable for bioenergy generating because of the high organic matter content. Anaerobic digestion is the eldest technology for waste stabilization and...The wastes and the by-products of food industrial technologies are suitable for bioenergy generating because of the high organic matter content. Anaerobic digestion is the eldest technology for waste stabilization and however by controlled decomposition a high value and marketable energy source can be produced. Whey is normally used as a component of dairy products or as an additive for food product. In our work we focused on another utilization method： biogas generating from membrane separated fractions i.e.： permeate and concentrate of whey. The effect of the pH, thermal, microwave pre-treatment and their combinations on the biogas yield were investigated. Our results showed that the applied pre-treatments had significant effect on biogas production. In consequence of the hydrolysis of large molecules the biodegradability of the pre-treated whey fractions was enhanced, therefore the biogas and methane production yield increased significantly.展开更多
基金This work was supported by the Open Research Fund of Key Laboratory of Atmospheric Composition and Optical Radiation, Chinese Academy of Sciences （No.J J-10-04）, Knowledge Innovation Foundation of Chinese Academy of Sciences （KJCX2-YW-N24）, and the National Natural Science Foundation of China （No.40975080 and No.10979061）.
文摘The composition of products formed from photooxidation of the aromatic hydrocarbon toluene was investigated. The OH-initiated photooxidation experiments were conducted by irradiating toluene/CH3ONO/NO/air mixtures in a smog chamber, the gaseous products were detected under the supersonic beam conditions by utilizing vacuum ultraviolet photoionization mass spectrometer using synchrotron radiation in real-time. And an aerosol time-of-flight mass spectrometer was used to provide on-line measurements of the individual secondary organic aerosol particle resulting from irradiating toluene. The experimental results demonstrated that there were some differences between the gaseous products and that of particle-phase, the products of glyoxal, 2-hydroxyl-3-oxo-butanal, nitrotoluene, and methyl-nitrophenol only existed in the particle-phase. However, furane, methylglyoxal, 2-methylfurane, benzaldehyde, cresol, and benzoic acid were the predominant photooxidation products in both the gas phase and particle phase.
文摘As a matured technique used in many fields,the distributed computer system is still a new management method for the aeronautical electrical power distribution system in our country. In this paper, a novel aircraft electrical power distribution system based on the distributed computer system is proposed. The principles, features and structure of the aircraft electrical power distribution system and the distributed computer system named electrical load management system (ELMS) are studied. The ELMS composed of four electrical load management centers (ELMCs) and two power source processors (PSPs) operates in the 1553B buses. Principles of the ELMCs and the PSPs are introduced. With the application of the distributed computer system, the aircraft electrical power distribution system is simple, adaptable and flexible.
基金the financial supports from the National Natural Science Foundation of China(Nos.51974373,51874365,62133016)the Major Scientific and Technological Innovation Projects of Shandong Province,China(No.2019JZZY020123)the Fundamental Research Funds for the Central Universities of Central South University,China(No.2019zzts242)。
文摘In view of the unclear cause of perfluorocarbons(PFCs)emission in the anode effect stage of aluminum electrolysis,the microscopic formation mechanism of PFCs was studied by density functional theory calculation and X-ray photoelectron spectroscopy(XPS).It is found that the discharge of fluorine containing anions([F]−)on carbon anode first causes the substitution of C—H by C—F and further results in the saturation of aromatic C—C bonds,leading to the appearance of—CF_(3)or—C_(2)F_(5)group through six-carbon-ring opening.Elimination of—CF_(3)and—C_(2)F_(5) with F atom could be a likely mechanism of CF_(4) and C_(2)F_(6) formation.XPS results confirm that different types of—CF_(x) group can be formed on anode surface during electrolysis,and the possibility that[F]−discharges continuously at the C edge and finally forms different C—F bonds in quantum mechanical calculation was verified.
文摘The wastes and the by-products of food industrial technologies are suitable for bioenergy generating because of the high organic matter content. Anaerobic digestion is the eldest technology for waste stabilization and however by controlled decomposition a high value and marketable energy source can be produced. Whey is normally used as a component of dairy products or as an additive for food product. In our work we focused on another utilization method： biogas generating from membrane separated fractions i.e.： permeate and concentrate of whey. The effect of the pH, thermal, microwave pre-treatment and their combinations on the biogas yield were investigated. Our results showed that the applied pre-treatments had significant effect on biogas production. In consequence of the hydrolysis of large molecules the biodegradability of the pre-treated whey fractions was enhanced, therefore the biogas and methane production yield increased significantly.
