Stringent regulations and environmental concerns make the production of clean fuels with low sulfur content compulsory for the petroleum refining industry.Because of ease of operation without high energy consumption,t...Stringent regulations and environmental concerns make the production of clean fuels with low sulfur content compulsory for the petroleum refining industry.Because of ease of operation without high energy consumption,the adsorption of sulfur compounds seems the most promising process.Central composite design was used to optimize parameters influencing the synthesis of dispersed carbon nanoparticles（CNPs）,a new class of sorbents,in order to obtain an excellent adsorbent for desulfurization of liquid fuel.The optimized dispersed CNPs,which are immiscible in liquid fuel,can effectively adsorb different benzothiophenic compounds.Equilibrium adsorption was achieved within 2 min for benzothiophene,dibenzothiophene,and 4,6-dimethyldibenzothiophene with removal efficiency values of 75 %,83 %,and 52 %,respectively.The rate of desulfurization by the prepared CNPs in the present work is seven times higher than the previously reported CNPs.Optimized CNPs were characterized by different techniques.Finally,the effect of the mass of CNPs on the removal efficiency was studied as well.展开更多
Selecting a cost optimum subset of discrete-value dispersion compensation modules (DV-DCMs) subject to maximum module count from an available set of DV-DCMs is a NP-hard problem. We derive a novel dynamic programming ...Selecting a cost optimum subset of discrete-value dispersion compensation modules (DV-DCMs) subject to maximum module count from an available set of DV-DCMs is a NP-hard problem. We derive a novel dynamic programming algorithm with pseudo-polynomial time bound and show that DV-DCM cost re-scaling can improve the running time.展开更多
A finite impulse-response microwave photonic filter is typically achieved based on spectrum-shaped optical frequency combs and a dispersive element. We propose an analytical model to describe the amplitude responses o...A finite impulse-response microwave photonic filter is typically achieved based on spectrum-shaped optical frequency combs and a dispersive element. We propose an analytical model to describe the amplitude responses of the sidelobes. The model shows that the sidelobe suppression ratio is limited by the spectrum structure of the optical combs. By taking Gaussian-profiled combs as an example, it is both theoretically and experimentally proved that the suppression ratio can be improved by optimizing the spectral power range, which is defined as the ratio of the maximum tap weight to the minimum tap weight.展开更多
基金financial support from Bu-Ali Sina University was gratefully acknowledged
文摘Stringent regulations and environmental concerns make the production of clean fuels with low sulfur content compulsory for the petroleum refining industry.Because of ease of operation without high energy consumption,the adsorption of sulfur compounds seems the most promising process.Central composite design was used to optimize parameters influencing the synthesis of dispersed carbon nanoparticles（CNPs）,a new class of sorbents,in order to obtain an excellent adsorbent for desulfurization of liquid fuel.The optimized dispersed CNPs,which are immiscible in liquid fuel,can effectively adsorb different benzothiophenic compounds.Equilibrium adsorption was achieved within 2 min for benzothiophene,dibenzothiophene,and 4,6-dimethyldibenzothiophene with removal efficiency values of 75 %,83 %,and 52 %,respectively.The rate of desulfurization by the prepared CNPs in the present work is seven times higher than the previously reported CNPs.Optimized CNPs were characterized by different techniques.Finally,the effect of the mass of CNPs on the removal efficiency was studied as well.
文摘Selecting a cost optimum subset of discrete-value dispersion compensation modules (DV-DCMs) subject to maximum module count from an available set of DV-DCMs is a NP-hard problem. We derive a novel dynamic programming algorithm with pseudo-polynomial time bound and show that DV-DCM cost re-scaling can improve the running time.
基金supported by National"973"Program of China(Nos.2012CB315603 and 2012CB315604)the National Natural Science Foundation of China(Nos.61321004,61420106003,and 61427813)
文摘A finite impulse-response microwave photonic filter is typically achieved based on spectrum-shaped optical frequency combs and a dispersive element. We propose an analytical model to describe the amplitude responses of the sidelobes. The model shows that the sidelobe suppression ratio is limited by the spectrum structure of the optical combs. By taking Gaussian-profiled combs as an example, it is both theoretically and experimentally proved that the suppression ratio can be improved by optimizing the spectral power range, which is defined as the ratio of the maximum tap weight to the minimum tap weight.
