This paper addresses the issue of modeling of the hydraulic long transmission line. In its base, such model is nonlinear with distributed parameters. Since general solution in closed-form for such model in time-domain...This paper addresses the issue of modeling of the hydraulic long transmission line. In its base, such model is nonlinear with distributed parameters. Since general solution in closed-form for such model in time-domain is not available, certain simplifications have to be introduced. The pipeline in the paper has been divided to a cascaded network of n segments so that a model with lumped parameters could be reached. For segment modeling, a standard library of bond graphs element has been used. On the basis of models with lumped parameters, the effect of the number of segments, pipeline length and effective bulk modulus on the dynamics of long transmission line have been analyzed.展开更多
Objective: To study the prevalence and pathogenesis of transfusion-transmitted virus (TTV) in hemodialysis patients. Methods: Serum TTV DNA was tested in 69 hemodialysis patients from our hospital by nested-PCR using ...Objective: To study the prevalence and pathogenesis of transfusion-transmitted virus (TTV) in hemodialysis patients. Methods: Serum TTV DNA was tested in 69 hemodialysis patients from our hospital by nested-PCR using primers from a conservative region of TTV genenome, gene sequence analysis and detection of hepatitis C virus antibody (anti-HCV) and the levels of alanine transaminase (ALT) were determined simultaneously. Results: The overall prevalence of TTV viremia was 27.5%. The PCR-amplified gene fragment from one patient was sequenced, and its Sequence homologies with TTV-UHI, TTV-TA278, TTVCHN1 and TTVCHN2 ranged from 89% to 100%, and its deduced amino acid sequence homologies with these 4 isolates ranged from 87% to 100%. There was no significant difference in 1TV prevalence between anti-UCV positive and negative patients (P＞0.05). No significant elevation of ALT is found in all patients. Conclusion: High prevalence of TTV infection is found among hemodialysis patients, and TTV infection has no significant association with HCV infection or elevation of ALT.展开更多
This paper presents the results of experiments and numerical simulation of the turbulent swirling flow and heat transfer in a duct.The calculated results are in good agreement with data obtained by measurements.It is ...This paper presents the results of experiments and numerical simulation of the turbulent swirling flow and heat transfer in a duct.The calculated results are in good agreement with data obtained by measurements.It is found that the swirling flow promotes heat transfer to the wall of the duct;the swirl numbers are dependent upon the vane exit angles of the swirler,distance from the swirler and the duct Reynolds number.But the decay of swirling flow in streamwise direction is related to local Reynolds numbers and is independent of the swirler exit angle.The swirl flow characteristics presented in this paper may be used for engineering purposes.展开更多
The mechanism of heat transfer enhancement by liquid film on the channel walls has been investigated in laminar mixed convective flows. The temperature distribution, velocity and mass fraction distributions, and the e...The mechanism of heat transfer enhancement by liquid film on the channel walls has been investigated in laminar mixed convective flows. The temperature distribution, velocity and mass fraction distributions, and the effects of the wetted wall temperatures and the Reynolds number on the momentum,heat and mass transfer were examined in details. Results show that the liquid film can enhance heat transfer along the wetted walls by 5-10 times.展开更多
For the development of ultra-sensitive electrical bio/chemical sensors based on nanowire field effect transistors （FETs）, the influence of the ions in the solution on the electron transport has to be understood. For...For the development of ultra-sensitive electrical bio/chemical sensors based on nanowire field effect transistors （FETs）, the influence of the ions in the solution on the electron transport has to be understood. For this purpose we establish a simulation platform for nanowire FETs in the liquid environment by implementing the modified Poisson-Boltzmann model into Landauer transport theory. We investigate the changes of the electric potential and the transport characteristics due to the ions. The reduction of sensitivity of the sensors due to the screening effect from the electrolyte could be successfully reproduced. We also fabricated silicon nanowire Schottky-barrier FETs and our model could capture the observed reduction of the current with increasing ionic concentration. This shows that our simulation platform can be used to interpret ongoing experiments, to design nanowire FETs, and it also gives insight into controversial issues such as whether ions in the buffer solution affect the transport characteristics or not.展开更多
A theory for multi-pump and multi-motor hydraulic systems is presented in this paper based on the analysis of the advantages and disadvantages of the popular hydraulic transmission and the double-stator motor(pump).By...A theory for multi-pump and multi-motor hydraulic systems is presented in this paper based on the analysis of the advantages and disadvantages of the popular hydraulic transmission and the double-stator motor(pump).By taking the single-acting fixed displacement multi-pump and multi-motor driving system as an example,the output speeds in a variety of connections of this novel hydraulic transmission are analyzed theoretically.This research work lays a theoretical foundation for the study of the multi-pump and multi-motor driving system and for the design of the system principle diagram.展开更多
Ethanol-water binary mixtures with 7 different mole fractions of ethanol ranging from 0 to 1 were adopted as testing liquids in the experiment. The vertical heating tube was inserted in porous matrix composed of five ...Ethanol-water binary mixtures with 7 different mole fractions of ethanol ranging from 0 to 1 were adopted as testing liquids in the experiment. The vertical heating tube was inserted in porous matrix composed of five well sorted glass beads whose diameters range from 0.5 to 4.3 mm. Due to the effect of composition, the trend of combination of vapor bubbles was reduced, resulting in the increase of peak heat flux of binary mixture. With the increase of ethanol mole fraction, 0.5 mm diameter bead had lower value of peak heat flux, while for pure liquid the critical state is difficult to appear. With given diameter of glass bead, there existed an optimum value of mole fraction of ethanol, which was decreased with the increase of bead diameter. A dimensionless heat transfer coefficient was predicted through the introduction of a dimensionless parameter of porous matrix, which agreed with the experimental results satisfactorily.展开更多
A room temperature ionic liquid crystal, 1-dodecyl-3-ethylimidazolium iodide （C12EImI）, and an ionic liquid, 1-decyl-3- ethylimidazolium iodide （Cl0EImI）, have been synthesized, characterized and employed as the e...A room temperature ionic liquid crystal, 1-dodecyl-3-ethylimidazolium iodide （C12EImI）, and an ionic liquid, 1-decyl-3- ethylimidazolium iodide （Cl0EImI）, have been synthesized, characterized and employed as the electrolyte for dye-sensitized solar cells （DSSC）. The physicochemical properties show that a smectic A （SmA） phase with a lamellar structure is formed in CIzEImI. Both C^2EImI and Cl0EImI have good electrochemical and thermal stability facilitating their use in DSSC. The steady-state voltammograms reveal that the diffusion coefficient of I3- in C^2EImI is larger than that in CmEImI, which is at- tributed to the existence of the SmA phase in Ca2EImI. Because the iodide species are located between the layers of imidazo- lium cations in CjzEImI, exchange reaction-based diffusion is increased with a consequent increase in, the overall diffusion. The electrochemical impedance spectrum reveals that charge recombination at the dyed TiOJelectrolyte interface of a C12EImI-based DSSC is reduced due to the increase in I3- diffusion, resulting in higher open-circuit voltage. Moreover, both short-circuit current density and fill factor of the Cl2EImI based DSSC increase, as a result of the increasing transport of I3 in C^2EImI. Consequently, the photoelectric conversion efficiency of C^2EImI-based DSSC is higher than that of the Cl0EImI-based DSSC.展开更多
文摘This paper addresses the issue of modeling of the hydraulic long transmission line. In its base, such model is nonlinear with distributed parameters. Since general solution in closed-form for such model in time-domain is not available, certain simplifications have to be introduced. The pipeline in the paper has been divided to a cascaded network of n segments so that a model with lumped parameters could be reached. For segment modeling, a standard library of bond graphs element has been used. On the basis of models with lumped parameters, the effect of the number of segments, pipeline length and effective bulk modulus on the dynamics of long transmission line have been analyzed.
文摘Objective: To study the prevalence and pathogenesis of transfusion-transmitted virus (TTV) in hemodialysis patients. Methods: Serum TTV DNA was tested in 69 hemodialysis patients from our hospital by nested-PCR using primers from a conservative region of TTV genenome, gene sequence analysis and detection of hepatitis C virus antibody (anti-HCV) and the levels of alanine transaminase (ALT) were determined simultaneously. Results: The overall prevalence of TTV viremia was 27.5%. The PCR-amplified gene fragment from one patient was sequenced, and its Sequence homologies with TTV-UHI, TTV-TA278, TTVCHN1 and TTVCHN2 ranged from 89% to 100%, and its deduced amino acid sequence homologies with these 4 isolates ranged from 87% to 100%. There was no significant difference in 1TV prevalence between anti-UCV positive and negative patients (P＞0.05). No significant elevation of ALT is found in all patients. Conclusion: High prevalence of TTV infection is found among hemodialysis patients, and TTV infection has no significant association with HCV infection or elevation of ALT.
文摘This paper presents the results of experiments and numerical simulation of the turbulent swirling flow and heat transfer in a duct.The calculated results are in good agreement with data obtained by measurements.It is found that the swirling flow promotes heat transfer to the wall of the duct;the swirl numbers are dependent upon the vane exit angles of the swirler,distance from the swirler and the duct Reynolds number.But the decay of swirling flow in streamwise direction is related to local Reynolds numbers and is independent of the swirler exit angle.The swirl flow characteristics presented in this paper may be used for engineering purposes.
文摘The mechanism of heat transfer enhancement by liquid film on the channel walls has been investigated in laminar mixed convective flows. The temperature distribution, velocity and mass fraction distributions, and the effects of the wetted wall temperatures and the Reynolds number on the momentum,heat and mass transfer were examined in details. Results show that the liquid film can enhance heat transfer along the wetted walls by 5-10 times.
文摘For the development of ultra-sensitive electrical bio/chemical sensors based on nanowire field effect transistors （FETs）, the influence of the ions in the solution on the electron transport has to be understood. For this purpose we establish a simulation platform for nanowire FETs in the liquid environment by implementing the modified Poisson-Boltzmann model into Landauer transport theory. We investigate the changes of the electric potential and the transport characteristics due to the ions. The reduction of sensitivity of the sensors due to the screening effect from the electrolyte could be successfully reproduced. We also fabricated silicon nanowire Schottky-barrier FETs and our model could capture the observed reduction of the current with increasing ionic concentration. This shows that our simulation platform can be used to interpret ongoing experiments, to design nanowire FETs, and it also gives insight into controversial issues such as whether ions in the buffer solution affect the transport characteristics or not.
基金supported by the National Natural Science Foundation of China (Grant No. 50975246)
文摘A theory for multi-pump and multi-motor hydraulic systems is presented in this paper based on the analysis of the advantages and disadvantages of the popular hydraulic transmission and the double-stator motor(pump).By taking the single-acting fixed displacement multi-pump and multi-motor driving system as an example,the output speeds in a variety of connections of this novel hydraulic transmission are analyzed theoretically.This research work lays a theoretical foundation for the study of the multi-pump and multi-motor driving system and for the design of the system principle diagram.
文摘Ethanol-water binary mixtures with 7 different mole fractions of ethanol ranging from 0 to 1 were adopted as testing liquids in the experiment. The vertical heating tube was inserted in porous matrix composed of five well sorted glass beads whose diameters range from 0.5 to 4.3 mm. Due to the effect of composition, the trend of combination of vapor bubbles was reduced, resulting in the increase of peak heat flux of binary mixture. With the increase of ethanol mole fraction, 0.5 mm diameter bead had lower value of peak heat flux, while for pure liquid the critical state is difficult to appear. With given diameter of glass bead, there existed an optimum value of mole fraction of ethanol, which was decreased with the increase of bead diameter. A dimensionless heat transfer coefficient was predicted through the introduction of a dimensionless parameter of porous matrix, which agreed with the experimental results satisfactorily.
基金supported by the National Basic Research Program of China(2011CBA00700)the National High Technology Research and Development Program of China(2011AA050510)the National Natural Science Foundation of China(21273242,21003130,21173227)
文摘A room temperature ionic liquid crystal, 1-dodecyl-3-ethylimidazolium iodide （C12EImI）, and an ionic liquid, 1-decyl-3- ethylimidazolium iodide （Cl0EImI）, have been synthesized, characterized and employed as the electrolyte for dye-sensitized solar cells （DSSC）. The physicochemical properties show that a smectic A （SmA） phase with a lamellar structure is formed in CIzEImI. Both C^2EImI and Cl0EImI have good electrochemical and thermal stability facilitating their use in DSSC. The steady-state voltammograms reveal that the diffusion coefficient of I3- in C^2EImI is larger than that in CmEImI, which is at- tributed to the existence of the SmA phase in Ca2EImI. Because the iodide species are located between the layers of imidazo- lium cations in CjzEImI, exchange reaction-based diffusion is increased with a consequent increase in, the overall diffusion. The electrochemical impedance spectrum reveals that charge recombination at the dyed TiOJelectrolyte interface of a C12EImI-based DSSC is reduced due to the increase in I3- diffusion, resulting in higher open-circuit voltage. Moreover, both short-circuit current density and fill factor of the Cl2EImI based DSSC increase, as a result of the increasing transport of I3 in C^2EImI. Consequently, the photoelectric conversion efficiency of C^2EImI-based DSSC is higher than that of the Cl0EImI-based DSSC.
