The attempt to obtain long-term observed data around some sea areas we concern is usually very hard or even impossible in practical offshore and ocean engineering situations. In this paper, by means of linear mean-squ...The attempt to obtain long-term observed data around some sea areas we concern is usually very hard or even impossible in practical offshore and ocean engineering situations. In this paper, by means of linear mean-square estimation method, a new way to extend short-term data to long-term ones is developed. The long-term data about concerning sea areas can be constructed via a series of long-term data obtained from neighbor oceanographic stations, through relevance analysis of different data series. It is effective to cover the insufficiency of time series prediction method＇s overdependence upon the length of data series, as well as the limitation of variable numbers adopted in multiple linear regression model. The storm surge data collected from three oceanographic stations located in Shandong Peninsula are taken as examples to analyze the number-selection effect of reference oceanographic stations（adjacent to the concerning sea area） and the correlation coefficients between sea sites which are selected for reference and for engineering projects construction respectively. By comparing the N-year return-period values which are calculated from observed raw data and processed data which are extended from finite data series by means of the linear mean-square estimation method, one can draw a conclusion that this method can give considerably good estimation in practical ocean engineering, in spite of different extreme value distributions about raw and processed data.展开更多
Spinal cord injury（SCI）frequently results in the permanent loss of function below the level of injury due to the failure of axonal regeneration in the adult mammalian central nervous system（CNS）.The limited intrin...Spinal cord injury（SCI）frequently results in the permanent loss of function below the level of injury due to the failure of axonal regeneration in the adult mammalian central nervous system（CNS）.The limited intrinsic growth capacity of adult neurons,a lack of growth-promoting factors and the multifactorial inhibitory microenvironment around the lesion site contribute to the lack of axonalregeneration. Strategies such as transplantation of cells,展开更多
Transverse-flux with high efficiency has been applied in Stirling engine and permanent magnet synchronous linear generator system,however it is restricted for large application because of low and complex process.A nov...Transverse-flux with high efficiency has been applied in Stirling engine and permanent magnet synchronous linear generator system,however it is restricted for large application because of low and complex process.A novel type of cylindrical,non-overlapping,transverse-flux,and permanent-magnet linear motor（TFPLM） is investigated,furthermore,a high power factor and less process complexity structure research is developed.The impact of magnetic leakage factor on power factor is discussed,by using the Finite Element Analysis（FEA） model of stirling engine and TFPLM,an optimization method for electro-magnetic design of TFPLM is proposed based on magnetic leakage factor.The relation between power factor and structure parameter is investigated,and a structure parameter optimization method is proposed taking power factor maximum as a goal.At last,the test bench is founded,starting experimental and generating experimental are performed,and a good agreement of simulation and experimental is achieved.The power factor is improved and the process complexity is decreased.This research provides the instruction to design high-power factor permanent-magnet linear generator.展开更多
Methanol is a very promising clean alternative fuel with low carbon content and high octane number,and this makes it well suited to the free-piston engine generator(FPEG)with variable compression ratio characteristics...Methanol is a very promising clean alternative fuel with low carbon content and high octane number,and this makes it well suited to the free-piston engine generator(FPEG)with variable compression ratio characteristics.To the authors’knowledge there are no relevant studies on the application of methanol for FPEG in recent literatures.In this paper,the effects of methanol substitution ratios(MSR)and load ratios on the performances and combustion characteristics of a methane/methanol dual-fuel FPEG have been investigated experimentally and numerically.The results show that the under the gas-liquid two-phase combustion startup strategy,the methane/methanol dual-fuel FPEG can be successfully started and achieve steady operation.Due to higher laminar flame speed(LFS)and the oxygen content of methanol resulting in a faster burning rate,the peak pressure increases by 43.9%from 1.344 MPa for pure methane to 1.934 MPa for 15%of MSR and the corresponding cycle-to-cycle variation decreases from 3.36 to 1.62.The FPEG operating frequency and indicated power gradually increase with the increase of the MSR.Both of them reach maximum values of 34.6 Hz and 193 W at 15%of MSR,which are increased by 19.3%and 49.6%in comparison with the pure methane.However,under specific MSR,both of them decrease with the load ratio increasing because of the large electromagnetic resistance force from the linear generator.CO and CH emissions decrease with the increase of MSR because methanol addition promotes complete combustion of mixture.NOx emissions gradually decrease with MSR increasing owing to the low combustion temperature resulting from the high latent heat of methanol evaporation.The numerical results show that with the increase of MSR,the methane/methanol mixture presents faster flame propagation speed and higher combustion efficiency;while the ignition delay as well as CA10,CA50 and CA90 is significantly shortened due to the increase of active radicals such as H,OH,O and H_(2)O_(2).展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51379195 and 41476078)the Natural Science Foundation of Shandong Province(Grant No.ZR2013EEM034)+2 种基金the Scientific Research Foundation of Science Technology Department of Zhejiang Province(Grant No.2015C34013)the Science Research Program of Zhoushan(Grant No.2014C41003)the Innovation Fund for Graduate Student of Shandong Province(Grant No.SDYY12152)
文摘The attempt to obtain long-term observed data around some sea areas we concern is usually very hard or even impossible in practical offshore and ocean engineering situations. In this paper, by means of linear mean-square estimation method, a new way to extend short-term data to long-term ones is developed. The long-term data about concerning sea areas can be constructed via a series of long-term data obtained from neighbor oceanographic stations, through relevance analysis of different data series. It is effective to cover the insufficiency of time series prediction method＇s overdependence upon the length of data series, as well as the limitation of variable numbers adopted in multiple linear regression model. The storm surge data collected from three oceanographic stations located in Shandong Peninsula are taken as examples to analyze the number-selection effect of reference oceanographic stations（adjacent to the concerning sea area） and the correlation coefficients between sea sites which are selected for reference and for engineering projects construction respectively. By comparing the N-year return-period values which are calculated from observed raw data and processed data which are extended from finite data series by means of the linear mean-square estimation method, one can draw a conclusion that this method can give considerably good estimation in practical ocean engineering, in spite of different extreme value distributions about raw and processed data.
基金Supported by grants from the Deutsche Forschungsgemeinschaft(BL414/3-1)International Foundation for Research in Paraplegia+2 种基金the Indiana University Health-Indiana University School of Medicine Strategic Research InitiativeIndiana Spinal Cord and Brain Injury Research FundMorton Cure Paralysis Fund to AB and a Heinz Gotze Memorial Fellowship to SL
文摘Spinal cord injury（SCI）frequently results in the permanent loss of function below the level of injury due to the failure of axonal regeneration in the adult mammalian central nervous system（CNS）.The limited intrinsic growth capacity of adult neurons,a lack of growth-promoting factors and the multifactorial inhibitory microenvironment around the lesion site contribute to the lack of axonalregeneration. Strategies such as transplantation of cells,
基金Supported by National Natural Science Foundation of China(Grant No.50877013)
文摘Transverse-flux with high efficiency has been applied in Stirling engine and permanent magnet synchronous linear generator system,however it is restricted for large application because of low and complex process.A novel type of cylindrical,non-overlapping,transverse-flux,and permanent-magnet linear motor（TFPLM） is investigated,furthermore,a high power factor and less process complexity structure research is developed.The impact of magnetic leakage factor on power factor is discussed,by using the Finite Element Analysis（FEA） model of stirling engine and TFPLM,an optimization method for electro-magnetic design of TFPLM is proposed based on magnetic leakage factor.The relation between power factor and structure parameter is investigated,and a structure parameter optimization method is proposed taking power factor maximum as a goal.At last,the test bench is founded,starting experimental and generating experimental are performed,and a good agreement of simulation and experimental is achieved.The power factor is improved and the process complexity is decreased.This research provides the instruction to design high-power factor permanent-magnet linear generator.
基金supported by the Space Application System of China Manned Space Program.
文摘Methanol is a very promising clean alternative fuel with low carbon content and high octane number,and this makes it well suited to the free-piston engine generator(FPEG)with variable compression ratio characteristics.To the authors’knowledge there are no relevant studies on the application of methanol for FPEG in recent literatures.In this paper,the effects of methanol substitution ratios(MSR)and load ratios on the performances and combustion characteristics of a methane/methanol dual-fuel FPEG have been investigated experimentally and numerically.The results show that the under the gas-liquid two-phase combustion startup strategy,the methane/methanol dual-fuel FPEG can be successfully started and achieve steady operation.Due to higher laminar flame speed(LFS)and the oxygen content of methanol resulting in a faster burning rate,the peak pressure increases by 43.9%from 1.344 MPa for pure methane to 1.934 MPa for 15%of MSR and the corresponding cycle-to-cycle variation decreases from 3.36 to 1.62.The FPEG operating frequency and indicated power gradually increase with the increase of the MSR.Both of them reach maximum values of 34.6 Hz and 193 W at 15%of MSR,which are increased by 19.3%and 49.6%in comparison with the pure methane.However,under specific MSR,both of them decrease with the load ratio increasing because of the large electromagnetic resistance force from the linear generator.CO and CH emissions decrease with the increase of MSR because methanol addition promotes complete combustion of mixture.NOx emissions gradually decrease with MSR increasing owing to the low combustion temperature resulting from the high latent heat of methanol evaporation.The numerical results show that with the increase of MSR,the methane/methanol mixture presents faster flame propagation speed and higher combustion efficiency;while the ignition delay as well as CA10,CA50 and CA90 is significantly shortened due to the increase of active radicals such as H,OH,O and H_(2)O_(2).
