Based on the Gauss linear frequency modulated wavelet transform, a new characteristic index is presented, namely time frequency energy attenuation factor which can reflect the difference features of waveform in earthq...Based on the Gauss linear frequency modulated wavelet transform, a new characteristic index is presented, namely time frequency energy attenuation factor which can reflect the difference features of waveform in earthquake focus mechanism, wave traveling path and its attenuation characteristics in focal area or near field. In order to test its validity, we select the natural earthquakes and explosion or collapse events whose focus mechanisms vary obviously,and some natural earthquakes located at the same site or in a very small area. The study indicates that the time frequency energy attenuation factors of the natural earthquakes are obviously different with that of explosion or collapse events, and the change of the time frequency energy attenuation factors is relatively stable for the earthquakes under the normal seismicity background. Using the above mentioned method, it is expected to offer a useful criterion for strong earthquake prediction by continuous earthquake observation.展开更多
The evaluation of the relative stability of initial permeability has been made of the pre-an- nealed amorphous ferromagnetic alloys Fe_(76)Si_(10)B_(14),Fe_(40)Ni_(38)Mo_4B_(18) and (Fe_(0.1)Ni_(0.35)Co_(0.55))_78Si_8...The evaluation of the relative stability of initial permeability has been made of the pre-an- nealed amorphous ferromagnetic alloys Fe_(76)Si_(10)B_(14),Fe_(40)Ni_(38)Mo_4B_(18) and (Fe_(0.1)Ni_(0.35)Co_(0.55))_78Si_8B_(14) by the experimental values of average activation energy and fre- quency factors on the basis of the empirical expression deduced by experimental data of the kinetics of their permeability decay.Calculated results show that the relative stability of permeability is sufficient for practical uses in the temperature range within 100℃,although the permeability instability can not be substantially eliminated.In other words,the permeability decay is considerably small within a period of considerable length.展开更多
In this paper,the power law of particle size distributions (PSDs) in conventional water treatment processes is developed. After measuring the particle size distributions of raw-water,settled water and filtered water,a...In this paper,the power law of particle size distributions (PSDs) in conventional water treatment processes is developed. After measuring the particle size distributions of raw-water,settled water and filtered water,a mathematical model between particle diameter and the amount of particles was studied. The value of collision frequency factor β in the PSDs model can be used to represent the collision behavior of particles ,and can be used as foundation exponent to choose suitable coagulation to accelerate particles aggregation. At the same time,the relationship between the value of parameter K and the total particles volume V was deduced. K is defined as particle volume exponent,which can represent the total volume of particles. The degression degree of K shows the removal efficiency of potable water treatment units.展开更多
Existing methods of physiological signal analysis based on nonlinear dynamic theories only examine the complexity difference of the signals under a single sampling frequency.We developed a technique to measure the mul...Existing methods of physiological signal analysis based on nonlinear dynamic theories only examine the complexity difference of the signals under a single sampling frequency.We developed a technique to measure the multifractal characteristic parameter intimately associated with physiological activities through a frequency scale factor.This parameter is highly sensitive to physiological and pathological status.Mice received various drugs to imitate different physiological and pathological conditions,and the distributions of mass exponent spectrum curvature with scale factors from the electrocardiogram (ECG) signals of healthy and drug injected mice were determined.Next,we determined the characteristic frequency scope in which the signal was of the highest complexity and most sensitive to impaired cardiac function,and examined the relationships between heart rate,heartbeat dynamic complexity,and sensitive frequency scope of the ECG signal.We found that all animals exhibited a scale factor range in which the absolute magnitudes of ECG mass exponent spectrum curvature achieve the maximum,and this range (or frequency scope) is not changed with calculated data points or maximal coarse-grained scale factor.Further,the heart rate of mice was not necessarily associated with the nonlinear complexity of cardiac dynamics,but closely related to the most sensitive ECG frequency scope determined by characterization of this complex dynamic features for certain heartbeat conditions.Finally,we found that the health status of the hearts of mice was directly related to the heartbeat dynamic complexity,both of which were positively correlated within the scale factor around the extremum region of the multifractal parameter.With increasing heart rate,the sensitive frequency scope increased to a relatively high location.In conclusion,these data provide important theoretical and practical data for the early diagnosis of cardiac disorders.展开更多
Based on Mindlin plate models and Kirchhoff plate models,this study was concerned with the wave propagation characteristics in thick conventional and auxetic cellular structures,with the objective to clarify the effec...Based on Mindlin plate models and Kirchhoff plate models,this study was concerned with the wave propagation characteristics in thick conventional and auxetic cellular structures,with the objective to clarify the effects of negative Poisson＇s ratio,shear factor and orthotropic mechanical properties on the dynamic behaviors of thick plates.Numerical results revealed that the predictions using variable shear factor in Mindlin plate models resulted in high wave frequencies,which were more significant for plates with negative values of Poisson＇s ratio.The present study can be useful for the design of critical applications by varying the values of Poisson＇s ratio.展开更多
Abstract Objectives To investigate the relationship between the β-fibrinogen gene -455A/G polymorphism and plasma fibrinogen level and to determine the influence of the mutation on ischemic stroke. Methods Ninety-o...Abstract Objectives To investigate the relationship between the β-fibrinogen gene -455A/G polymorphism and plasma fibrinogen level and to determine the influence of the mutation on ischemic stroke. Methods Ninety-one patients (63.5±10.1 years) with ischemic stroke and 74 elderly control subjects (60.6±10.8 years) without any thromboembolic events and 98 healthy blood donators as young control (37.5±13.3 years) were enrolled in this trial. The β-fibrinogen gene -455A/G polymorphism was analyzed for all subjects by PCR-RFLP with the restrictive enzyme Hae Ⅲ, while plasma fibrinogen levels were obtained from the prothrombin time (PT) assay. For statistical analysis, the parameters were compared between any two different groups by the unpaired Student’s t test and the Chi-square test. Before analysis, log transformations for concentrations of fibrinogen were carried out.Results H2 allele frequency was higher in male ischemic stroke patients than in the elderly control (22.7% vs 7.1%, χ 2=5.56, P【0.02). There was no significant difference between the female groups. In those patients without any thromboembolic events (both elderly and young control groups), the frequency of H2 decreased with age (≤40, 21.3%; 41-59, 15.4%; and ≥60, 10.2%). In the male elderly and young control groups, the level of plasma fibrinogen was lower in the H1H1 genotype (287±96*!mg/dl and 234±58*!mg/dl) than in H1H2 and H2H2 (331±44*!mg/dl and 307±55*!mg/dl; t=2.53 and 9.67, P【0.05). In the female elderly groups, this tendency was not found.Conclusion Plasma fibrinogen expression is affected by the β-fibrinogen gene -455A/G polymorphism, and the H2 allele may be a risk factor for ischemic stroke in Chinese males.展开更多
This paper presents a low power tunable active inductor and RF band pass filter suitable for multiband RF front end circuits. The active inductor circuit uses the PMOS cascode structure as the negative transconductor ...This paper presents a low power tunable active inductor and RF band pass filter suitable for multiband RF front end circuits. The active inductor circuit uses the PMOS cascode structure as the negative transconductor of a gyrator to reduce the noise voltage. Also, this structure provides possible negative resistance to reduce the inductor loss with wide inductive bandwidth and high resonance frequency. The RF band pass filter is realized using the proposed active inductor with suitable input and output buffer stages. The tuning of the center frequency for multiband operation is achieved through the controllable current source. The designed active inductor and RF band pass filter are simulated in 180 nm and 45 nm CMOS process using the Synopsys HSPICE simulation tool and their performances are compared. The parameters, such as resonance frequency, tuning capability, noise and power dissipation, are analyzed for these CMOS technologies and discussed. The design of a third order band pass filter using an active inductor is also presented.展开更多
文摘Based on the Gauss linear frequency modulated wavelet transform, a new characteristic index is presented, namely time frequency energy attenuation factor which can reflect the difference features of waveform in earthquake focus mechanism, wave traveling path and its attenuation characteristics in focal area or near field. In order to test its validity, we select the natural earthquakes and explosion or collapse events whose focus mechanisms vary obviously,and some natural earthquakes located at the same site or in a very small area. The study indicates that the time frequency energy attenuation factors of the natural earthquakes are obviously different with that of explosion or collapse events, and the change of the time frequency energy attenuation factors is relatively stable for the earthquakes under the normal seismicity background. Using the above mentioned method, it is expected to offer a useful criterion for strong earthquake prediction by continuous earthquake observation.
文摘The evaluation of the relative stability of initial permeability has been made of the pre-an- nealed amorphous ferromagnetic alloys Fe_(76)Si_(10)B_(14),Fe_(40)Ni_(38)Mo_4B_(18) and (Fe_(0.1)Ni_(0.35)Co_(0.55))_78Si_8B_(14) by the experimental values of average activation energy and fre- quency factors on the basis of the empirical expression deduced by experimental data of the kinetics of their permeability decay.Calculated results show that the relative stability of permeability is sufficient for practical uses in the temperature range within 100℃,although the permeability instability can not be substantially eliminated.In other words,the permeability decay is considerably small within a period of considerable length.
基金Sponsored by the National Basic Research Program of China(973)(Grant No.2004CB41850)the Natural Science Foundation of Heilongjiang Prov-ince(Grant No.E200609)
文摘In this paper,the power law of particle size distributions (PSDs) in conventional water treatment processes is developed. After measuring the particle size distributions of raw-water,settled water and filtered water,a mathematical model between particle diameter and the amount of particles was studied. The value of collision frequency factor β in the PSDs model can be used to represent the collision behavior of particles ,and can be used as foundation exponent to choose suitable coagulation to accelerate particles aggregation. At the same time,the relationship between the value of parameter K and the total particles volume V was deduced. K is defined as particle volume exponent,which can represent the total volume of particles. The degression degree of K shows the removal efficiency of potable water treatment units.
基金supported by the National Natural Science Foundation of China (Grant No. 61003169)the Ph.D. Programs Foundation of Ministry of Education of China (Grant No. 20090095120013)the Technology Funding Project of China University of Mining and Technology (Grant No. 2008C004)
文摘Existing methods of physiological signal analysis based on nonlinear dynamic theories only examine the complexity difference of the signals under a single sampling frequency.We developed a technique to measure the multifractal characteristic parameter intimately associated with physiological activities through a frequency scale factor.This parameter is highly sensitive to physiological and pathological status.Mice received various drugs to imitate different physiological and pathological conditions,and the distributions of mass exponent spectrum curvature with scale factors from the electrocardiogram (ECG) signals of healthy and drug injected mice were determined.Next,we determined the characteristic frequency scope in which the signal was of the highest complexity and most sensitive to impaired cardiac function,and examined the relationships between heart rate,heartbeat dynamic complexity,and sensitive frequency scope of the ECG signal.We found that all animals exhibited a scale factor range in which the absolute magnitudes of ECG mass exponent spectrum curvature achieve the maximum,and this range (or frequency scope) is not changed with calculated data points or maximal coarse-grained scale factor.Further,the heart rate of mice was not necessarily associated with the nonlinear complexity of cardiac dynamics,but closely related to the most sensitive ECG frequency scope determined by characterization of this complex dynamic features for certain heartbeat conditions.Finally,we found that the health status of the hearts of mice was directly related to the heartbeat dynamic complexity,both of which were positively correlated within the scale factor around the extremum region of the multifractal parameter.With increasing heart rate,the sensitive frequency scope increased to a relatively high location.In conclusion,these data provide important theoretical and practical data for the early diagnosis of cardiac disorders.
基金Project supported by the National Natural Science Foundation of China(No.11172239)the 111 project(No.B07050)the Doctoral Program Foundation of Education Ministry of China(20126102110023)
文摘Based on Mindlin plate models and Kirchhoff plate models,this study was concerned with the wave propagation characteristics in thick conventional and auxetic cellular structures,with the objective to clarify the effects of negative Poisson＇s ratio,shear factor and orthotropic mechanical properties on the dynamic behaviors of thick plates.Numerical results revealed that the predictions using variable shear factor in Mindlin plate models resulted in high wave frequencies,which were more significant for plates with negative values of Poisson＇s ratio.The present study can be useful for the design of critical applications by varying the values of Poisson＇s ratio.
文摘Abstract Objectives To investigate the relationship between the β-fibrinogen gene -455A/G polymorphism and plasma fibrinogen level and to determine the influence of the mutation on ischemic stroke. Methods Ninety-one patients (63.5±10.1 years) with ischemic stroke and 74 elderly control subjects (60.6±10.8 years) without any thromboembolic events and 98 healthy blood donators as young control (37.5±13.3 years) were enrolled in this trial. The β-fibrinogen gene -455A/G polymorphism was analyzed for all subjects by PCR-RFLP with the restrictive enzyme Hae Ⅲ, while plasma fibrinogen levels were obtained from the prothrombin time (PT) assay. For statistical analysis, the parameters were compared between any two different groups by the unpaired Student’s t test and the Chi-square test. Before analysis, log transformations for concentrations of fibrinogen were carried out.Results H2 allele frequency was higher in male ischemic stroke patients than in the elderly control (22.7% vs 7.1%, χ 2=5.56, P【0.02). There was no significant difference between the female groups. In those patients without any thromboembolic events (both elderly and young control groups), the frequency of H2 decreased with age (≤40, 21.3%; 41-59, 15.4%; and ≥60, 10.2%). In the male elderly and young control groups, the level of plasma fibrinogen was lower in the H1H1 genotype (287±96*!mg/dl and 234±58*!mg/dl) than in H1H2 and H2H2 (331±44*!mg/dl and 307±55*!mg/dl; t=2.53 and 9.67, P【0.05). In the female elderly groups, this tendency was not found.Conclusion Plasma fibrinogen expression is affected by the β-fibrinogen gene -455A/G polymorphism, and the H2 allele may be a risk factor for ischemic stroke in Chinese males.
文摘This paper presents a low power tunable active inductor and RF band pass filter suitable for multiband RF front end circuits. The active inductor circuit uses the PMOS cascode structure as the negative transconductor of a gyrator to reduce the noise voltage. Also, this structure provides possible negative resistance to reduce the inductor loss with wide inductive bandwidth and high resonance frequency. The RF band pass filter is realized using the proposed active inductor with suitable input and output buffer stages. The tuning of the center frequency for multiband operation is achieved through the controllable current source. The designed active inductor and RF band pass filter are simulated in 180 nm and 45 nm CMOS process using the Synopsys HSPICE simulation tool and their performances are compared. The parameters, such as resonance frequency, tuning capability, noise and power dissipation, are analyzed for these CMOS technologies and discussed. The design of a third order band pass filter using an active inductor is also presented.
