Several recently developed analytical techniques, based on high-end mass spectrometry and chromatography, for dealing with challenges in petroleum characterization are reported. Folded flight path time-of-flight mass ...Several recently developed analytical techniques, based on high-end mass spectrometry and chromatography, for dealing with challenges in petroleum characterization are reported. Folded flight path time-of-flight mass spectrometry provides resolving power up to 100000, enabling accurate mass measurement for molecular formula determination with high confidence. Atmos- pheric pressure chemical ionization （APCI） can be used in both gas chromatography （GC, as APGC） and liquid chromatog- raphy （LC） for analyzing non-polar hydrocarbons as well as polar compounds. The improvement in chromatography facilitates the mass spectrometric analysis through online coupling. Comprehensive two-dimensional gas chromatography （GCxGC） re- solves overlapping components, rendering accurate identification and quantitation. Supercritical fluid extraction has been de- veloped as an alternative method to replace traditional solvent extraction methods and eliminate the use of large volumes of solvents that can be harmful to health and environment. Supercritical fluid chromatography （SFC） has been developed as a convergence of GC and LC chromatographic techniques. The use of SFC for heavy oils and residua has been demonstrated. Prospective developments in the use of mass spectrometric and chromatographic methods for petroleum characterization are also described.展开更多
By using our computational fluid dynamic models, a new type of single engine capable of operating over a wide range of Mach numbers from subsonic to hypersonic regimes is proposed for airplanes, whereas traditional pi...By using our computational fluid dynamic models, a new type of single engine capable of operating over a wide range of Mach numbers from subsonic to hypersonic regimes is proposed for airplanes, whereas traditional piston engines, turbojet engines, and scram engines work only under a narrower range of operating conditions. The new engine has no compressors or turbines such as those used in conventional turbojet engines. An important point is its system of super multijets that collide to compress gas for the transonic regime. Computational fluid dynamics is applied to clarify the potential of this engine. The peak pressure at the combustion center is over 2.5 MPa, while that just before ignition is over 1.0 MPa. The maximum power of this engine will be sufficient for actual use. Under the conditions of higher Mach numbers, the main intake passage located in front of the super multijet nozzles, takes in air more. That results in a ram or scramjet engine for supersonic and hypersonic conditions.展开更多
文摘Several recently developed analytical techniques, based on high-end mass spectrometry and chromatography, for dealing with challenges in petroleum characterization are reported. Folded flight path time-of-flight mass spectrometry provides resolving power up to 100000, enabling accurate mass measurement for molecular formula determination with high confidence. Atmos- pheric pressure chemical ionization （APCI） can be used in both gas chromatography （GC, as APGC） and liquid chromatog- raphy （LC） for analyzing non-polar hydrocarbons as well as polar compounds. The improvement in chromatography facilitates the mass spectrometric analysis through online coupling. Comprehensive two-dimensional gas chromatography （GCxGC） re- solves overlapping components, rendering accurate identification and quantitation. Supercritical fluid extraction has been de- veloped as an alternative method to replace traditional solvent extraction methods and eliminate the use of large volumes of solvents that can be harmful to health and environment. Supercritical fluid chromatography （SFC） has been developed as a convergence of GC and LC chromatographic techniques. The use of SFC for heavy oils and residua has been demonstrated. Prospective developments in the use of mass spectrometric and chromatographic methods for petroleum characterization are also described.
文摘By using our computational fluid dynamic models, a new type of single engine capable of operating over a wide range of Mach numbers from subsonic to hypersonic regimes is proposed for airplanes, whereas traditional piston engines, turbojet engines, and scram engines work only under a narrower range of operating conditions. The new engine has no compressors or turbines such as those used in conventional turbojet engines. An important point is its system of super multijets that collide to compress gas for the transonic regime. Computational fluid dynamics is applied to clarify the potential of this engine. The peak pressure at the combustion center is over 2.5 MPa, while that just before ignition is over 1.0 MPa. The maximum power of this engine will be sufficient for actual use. Under the conditions of higher Mach numbers, the main intake passage located in front of the super multijet nozzles, takes in air more. That results in a ram or scramjet engine for supersonic and hypersonic conditions.
