The numerical calculation method is widely used in the evaluation of slope stability,but it cannot take the randomness and fuzziness into account that exist in rock and soil engineering objectively.The fuzzy optimizat...The numerical calculation method is widely used in the evaluation of slope stability,but it cannot take the randomness and fuzziness into account that exist in rock and soil engineering objectively.The fuzzy optimization theory is thus introduced to the evaluation of slope stability by this paper and a method of fuzzy optimal selection of similar slopes is put forward to analyze slope stability.By comparing the relative membership degrees that the evaluated object sample of slope is similar to the source samples of which the stabilities are detected clearly,the source sample with the maximal relative membership degree will be chosen as the best similar one to the object sample,and the stability of the object sample can be evaluated by that of the best similar source sample.In the process many uncertain influential factors are considered and characteristics and knowledge of the source samples are obtained.The practical calculation indicates that it can achieve good results to evaluate slope stability by using this method.展开更多
A 20 Gsample/s photonic analog-to-digital converter is constructed using a 4-switching-wavelength repetitive sampling pulse source. The signal-to-noise and distortion ratio (SINAD) is measured to be 44.5 dB and corres...A 20 Gsample/s photonic analog-to-digital converter is constructed using a 4-switching-wavelength repetitive sampling pulse source. The signal-to-noise and distortion ratio (SINAD) is measured to be 44.5 dB and corresponds to 7 effective number of bits.展开更多
Thermochemical biomass gasification,followedby conversion of the produced syngas to fuels andelectrical power,is a promising energy alternative.Realworldcharacterization of particulate matter(PM)and othercontaminants ...Thermochemical biomass gasification,followedby conversion of the produced syngas to fuels andelectrical power,is a promising energy alternative.Realworldcharacterization of particulate matter(PM)and othercontaminants in the syngas is important to minimizedamage and ensure efficient operation of the engines itpowers and the fuels created from it.A dilution samplingsystem is demonstrated to quantify PM in syngas generatedfrom two gasification plants utilizing different biomassfeedstocks:a BioMax®15 Biopower System that uses rawand torrefied woodchips as feedstocks,and an integratedbiorefinery(IBR)that uses rice hulls and woodchips asfeedstocks.PM_(2.5)mass concentrations in syngas from theIBR downstream of the purification system were 12.8-13.7μg·m^(-3),which were significantly lower than themaximum level for catalyst protection(500μg·m^(-3))andwere 2-3 orders of magnitude lower than those inBioMax®15 syngas(2247-4835μg·m^(-3)).Ultrafine particlenumber concentration and PM_(2.5)chemical constituentswere also much lower in the IBR syngas than in theBioMax®15.The dilution sampling system enabledreliable measurements over a wide range of concentrations:the use of high sensitivity instruments allowed measurementat very low concentrations(~1μg·m^(-3)),while theflexibility of dilution minimized sampling problems thatare commonly encountered due to high levels of tars in rawsyngas(~1 g·m^(-3)).展开更多
基金Sponsored by the Natural Science Foundation of Liaoning Province in China(Grant No.20022106).
文摘The numerical calculation method is widely used in the evaluation of slope stability,but it cannot take the randomness and fuzziness into account that exist in rock and soil engineering objectively.The fuzzy optimization theory is thus introduced to the evaluation of slope stability by this paper and a method of fuzzy optimal selection of similar slopes is put forward to analyze slope stability.By comparing the relative membership degrees that the evaluated object sample of slope is similar to the source samples of which the stabilities are detected clearly,the source sample with the maximal relative membership degree will be chosen as the best similar one to the object sample,and the stability of the object sample can be evaluated by that of the best similar source sample.In the process many uncertain influential factors are considered and characteristics and knowledge of the source samples are obtained.The practical calculation indicates that it can achieve good results to evaluate slope stability by using this method.
文摘A 20 Gsample/s photonic analog-to-digital converter is constructed using a 4-switching-wavelength repetitive sampling pulse source. The signal-to-noise and distortion ratio (SINAD) is measured to be 44.5 dB and corresponds to 7 effective number of bits.
基金Financial support was provided by the US DOE under awards DE-EE0000272 and DE-FG30-08CC00057.
文摘Thermochemical biomass gasification,followedby conversion of the produced syngas to fuels andelectrical power,is a promising energy alternative.Realworldcharacterization of particulate matter(PM)and othercontaminants in the syngas is important to minimizedamage and ensure efficient operation of the engines itpowers and the fuels created from it.A dilution samplingsystem is demonstrated to quantify PM in syngas generatedfrom two gasification plants utilizing different biomassfeedstocks:a BioMax®15 Biopower System that uses rawand torrefied woodchips as feedstocks,and an integratedbiorefinery(IBR)that uses rice hulls and woodchips asfeedstocks.PM_(2.5)mass concentrations in syngas from theIBR downstream of the purification system were 12.8-13.7μg·m^(-3),which were significantly lower than themaximum level for catalyst protection(500μg·m^(-3))andwere 2-3 orders of magnitude lower than those inBioMax®15 syngas(2247-4835μg·m^(-3)).Ultrafine particlenumber concentration and PM_(2.5)chemical constituentswere also much lower in the IBR syngas than in theBioMax®15.The dilution sampling system enabledreliable measurements over a wide range of concentrations:the use of high sensitivity instruments allowed measurementat very low concentrations(~1μg·m^(-3)),while theflexibility of dilution minimized sampling problems thatare commonly encountered due to high levels of tars in rawsyngas(~1 g·m^(-3)).
