We report on the current-voltage (I-V) and capacitance-voltage (C-V) characteristics of the Pd/Ti/n-InP Schottky barrier diodes (SBDs) in the temperature range 160-400 K in steps of 40 K. The barrier heights and ideal...We report on the current-voltage (I-V) and capacitance-voltage (C-V) characteristics of the Pd/Ti/n-InP Schottky barrier diodes (SBDs) in the temperature range 160-400 K in steps of 40 K. The barrier heights and ideality factors of Schottky contact are found in the range 0.35 eV (I-V), 0.73 eV (C-V) at 160 K and 0.63 eV (I-V), 0.61 eV (C-V) at 400 K, respectively. It is observed that the zero-bias barrier height decreases and ideality factor n increase with a decrease in temperature, this behaviour is attributed to barrier inhomogeneities by assuming Gaussian distribution at the interface. The calculated value of series resistance (Rs) from the forward I-V characteristics is decreased with an increase in temperature. The homogeneous barrier height value of approximately 0.71 eV for the Pd/Ti Schottky diode has been obtained from the linear relationship between the temperature-dependent experimentally effective barrier heights and ideality factors. The zero-bias barrier height ( ) versus 1/2kT plot has been drawn to obtain evidence of a Gaussian distribution of the barrier heights and values of = 0.80 eV and = 114 mV for the mean barrier height and standard deviation have been obtained from the plot, respectively. The modified Richardson ln(I0/T2)- ( ) versus 1000/T plot has a good linearity over the investigated temperature range and gives the mean barrier height ( ) and Richardson constant (A*) values as 0.796 eV and 6.16 Acm-2K-2 respectively. The discrepancy between Schottky barrier heights obtained from I-V and C-V measurements is also interpreted.展开更多
Background N-terminal pro-B-type natriuretic peptide （NT-proBNP） and high-sensitivity cardiac troponin T （hs-cTnT） are excellent biomarkers for detecting heart failure and subclinical myocardial injury.However,it ...Background N-terminal pro-B-type natriuretic peptide （NT-proBNP） and high-sensitivity cardiac troponin T （hs-cTnT） are excellent biomarkers for detecting heart failure and subclinical myocardial injury.However,it remains unclear whether subclinical myocardial injury is associated with NT-proBNP elevation in a community based population.Methods In a community based study,levels of hs-cTnT and of NT-proBNP were determined in 1 497 participants older than 45 years.The lower detection limit of the hs-cTnT assay used in the present study was 0.003 ng/ml.The association of hs-cTnT levels and NT-proBNP levels was analyzed.Results When the subjects with undetectable （〈0.003 ng/ml）,intermediate （0.003-0.014 ng/ml）,and elevated （≥0.014 ng/ml） levels of hs-cTnT were compared （r=0.175,P 〈0.001）,a strong association between the hs-cTnT levels and NT-proBNP levels was observed （β=-0.206,P 〈0.001; β=-0.118,P 〈0.001,respectively）.In multivariable analyses,older age and hs-cTnT were positively and independently associated with NT-proBNP levels （β=0.341,P 〈0.001; β=0.143,P 〈0.001,respectively）,and male gender and the levels of eGFR were inversely and independently associated with NT-proBNP levels.When the subjects with normal or elevated NT-proBNP were analyzed separately,the hs-cTnT level was not an independent predictor for the NT-proBNP level in the normal NT-proBNP group,whereas the hs-cTnT level was the only independent predictor for NT-proBNP level in the elevated NT-proBNP group （β=0.399,P 〈0.01）.Conclusions In this community based population,NT-proBNP elevation was common.In addition to female gender and older age,subclinical myocardial injury indicated by the hs-cTnT level was another important factor in NT-proBNP elevation.展开更多
The recently developed SCCDS composite tube,a novel variant of the pipe-in-pipe(PIP)structure,demonstrates strong potential for subsea pipeline applications.However,theoretical research regarding its structural behavi...The recently developed SCCDS composite tube,a novel variant of the pipe-in-pipe(PIP)structure,demonstrates strong potential for subsea pipeline applications.However,theoretical research regarding its structural behavior under compression-torsion loading and bearing capacity calculations remains limited,particularly concerning the influence of dual hydraulic pressures during operation.This study examines the impact of dual hydraulic pressures on the compressive-torsional behavior of SCCDS composite tubes.A finite element(FE)model was developed and validated against experimental results,comparing failure modes,full-range loading curves,and bearing capacity to elucidate the working mechanism under dual pressures.A parametric study was then conducted to examine the effects of geometric-physical parameters.Results demonstrate that dual pressures substantially enhance the bearing capacity of sandwich concrete by increasing the normal contact stress at the interface.Increasing concrete strength(f_(c))provides minimal enhancement to torsional resistance compared to the yielding strengths of outer tube(f_(yo))and inner tube(f_(yi)).Higher diameter-to-thickness ratios of outer tube(D_(o)/t_(o))and inner tube(D_(i)/t_(i))significantly reduce torsional capacity.At 1000 m water depth,increasing the D_(o)/t_(o)ratio from 27.5 to 36.67,55,and 110 reduces bearing capacity by 11.17%,23.08%,and 36.14%respectively.Strict measures should be implemented to prevent substantial reductions in strength and ductility for SCCDS composite tubes with large hollow ratios(e.g.,χ=0.849)or high axial compression ratios(e.g.,n=0.8).The study proposes a modified calculation method for determining N-T curves that incorporates dual hydraulic pressure effects,providing guidance for performance evaluation of novel SCCDS composite tubes in deep-sea engineering.展开更多
文摘We report on the current-voltage (I-V) and capacitance-voltage (C-V) characteristics of the Pd/Ti/n-InP Schottky barrier diodes (SBDs) in the temperature range 160-400 K in steps of 40 K. The barrier heights and ideality factors of Schottky contact are found in the range 0.35 eV (I-V), 0.73 eV (C-V) at 160 K and 0.63 eV (I-V), 0.61 eV (C-V) at 400 K, respectively. It is observed that the zero-bias barrier height decreases and ideality factor n increase with a decrease in temperature, this behaviour is attributed to barrier inhomogeneities by assuming Gaussian distribution at the interface. The calculated value of series resistance (Rs) from the forward I-V characteristics is decreased with an increase in temperature. The homogeneous barrier height value of approximately 0.71 eV for the Pd/Ti Schottky diode has been obtained from the linear relationship between the temperature-dependent experimentally effective barrier heights and ideality factors. The zero-bias barrier height ( ) versus 1/2kT plot has been drawn to obtain evidence of a Gaussian distribution of the barrier heights and values of = 0.80 eV and = 114 mV for the mean barrier height and standard deviation have been obtained from the plot, respectively. The modified Richardson ln(I0/T2)- ( ) versus 1000/T plot has a good linearity over the investigated temperature range and gives the mean barrier height ( ) and Richardson constant (A*) values as 0.796 eV and 6.16 Acm-2K-2 respectively. The discrepancy between Schottky barrier heights obtained from I-V and C-V measurements is also interpreted.
基金This study was supported by grants from the National Basic Research Program of China，Nature Science Foundation of China
文摘Background N-terminal pro-B-type natriuretic peptide （NT-proBNP） and high-sensitivity cardiac troponin T （hs-cTnT） are excellent biomarkers for detecting heart failure and subclinical myocardial injury.However,it remains unclear whether subclinical myocardial injury is associated with NT-proBNP elevation in a community based population.Methods In a community based study,levels of hs-cTnT and of NT-proBNP were determined in 1 497 participants older than 45 years.The lower detection limit of the hs-cTnT assay used in the present study was 0.003 ng/ml.The association of hs-cTnT levels and NT-proBNP levels was analyzed.Results When the subjects with undetectable （〈0.003 ng/ml）,intermediate （0.003-0.014 ng/ml）,and elevated （≥0.014 ng/ml） levels of hs-cTnT were compared （r=0.175,P 〈0.001）,a strong association between the hs-cTnT levels and NT-proBNP levels was observed （β=-0.206,P 〈0.001; β=-0.118,P 〈0.001,respectively）.In multivariable analyses,older age and hs-cTnT were positively and independently associated with NT-proBNP levels （β=0.341,P 〈0.001; β=0.143,P 〈0.001,respectively）,and male gender and the levels of eGFR were inversely and independently associated with NT-proBNP levels.When the subjects with normal or elevated NT-proBNP were analyzed separately,the hs-cTnT level was not an independent predictor for the NT-proBNP level in the normal NT-proBNP group,whereas the hs-cTnT level was the only independent predictor for NT-proBNP level in the elevated NT-proBNP group （β=0.399,P 〈0.01）.Conclusions In this community based population,NT-proBNP elevation was common.In addition to female gender and older age,subclinical myocardial injury indicated by the hs-cTnT level was another important factor in NT-proBNP elevation.
基金supported by the High-level Talent Research Startup Fund(Grant No.1608722024)of Xi’an University of Archit-ectureTechnology and the Shaanxi Province High-level Youth Talents Program(Grant No.Z20240589).
文摘The recently developed SCCDS composite tube,a novel variant of the pipe-in-pipe(PIP)structure,demonstrates strong potential for subsea pipeline applications.However,theoretical research regarding its structural behavior under compression-torsion loading and bearing capacity calculations remains limited,particularly concerning the influence of dual hydraulic pressures during operation.This study examines the impact of dual hydraulic pressures on the compressive-torsional behavior of SCCDS composite tubes.A finite element(FE)model was developed and validated against experimental results,comparing failure modes,full-range loading curves,and bearing capacity to elucidate the working mechanism under dual pressures.A parametric study was then conducted to examine the effects of geometric-physical parameters.Results demonstrate that dual pressures substantially enhance the bearing capacity of sandwich concrete by increasing the normal contact stress at the interface.Increasing concrete strength(f_(c))provides minimal enhancement to torsional resistance compared to the yielding strengths of outer tube(f_(yo))and inner tube(f_(yi)).Higher diameter-to-thickness ratios of outer tube(D_(o)/t_(o))and inner tube(D_(i)/t_(i))significantly reduce torsional capacity.At 1000 m water depth,increasing the D_(o)/t_(o)ratio from 27.5 to 36.67,55,and 110 reduces bearing capacity by 11.17%,23.08%,and 36.14%respectively.Strict measures should be implemented to prevent substantial reductions in strength and ductility for SCCDS composite tubes with large hollow ratios(e.g.,χ=0.849)or high axial compression ratios(e.g.,n=0.8).The study proposes a modified calculation method for determining N-T curves that incorporates dual hydraulic pressure effects,providing guidance for performance evaluation of novel SCCDS composite tubes in deep-sea engineering.
