The theory for measuring the time constant of thermocouple was introduced, and the method for measuring the time constant of NANMAC thermocouple by using dynamic calibration system of transient surface temperature sen...The theory for measuring the time constant of thermocouple was introduced, and the method for measuring the time constant of NANMAC thermocouple by using dynamic calibration system of transient surface temperature sensor was proposed. In this system, static and dynamic calibrations were conducted for infrared detectors and thermocouples, and then both temperature-time curves were obtained. Since the frequency response of infrared detector is superior to that of calibrat- ed thermocouple, the values measured by infrared detectors are taken as true values. Through dividing the values measured with thermocouples by those with infrared detectors, a normalized curve was obtained, based on which the time constant of thermocouple was measured. With this method, the experiments were carried out with NANMAC thermocouple to obtain its time constant. The results show that the method for measuring the time constant is feasible and the dynamic calibration of thermocouples can be achieved at microsecond and millisecond level. This research has a certain reference value for research and application of NANMAC thermocouple temperature sensor.展开更多
q-axis rotor flux can be chosen to form a model reference adaptive system(MRAS)updating rotor time constant online in induction motor drives.This paper presents a stability analysis of such a system with Popov’s hype...q-axis rotor flux can be chosen to form a model reference adaptive system(MRAS)updating rotor time constant online in induction motor drives.This paper presents a stability analysis of such a system with Popov’s hyperstability concept and small-signal linearization technique.At first,the stability of q-axis rotor flux based MRAS is proven with Popov’s Hyperstability theory.Then,to find out the guidelines for optimally designing the coefficients in the PI controller,acting as the adaption mechanism in the MRAS,small-signal model of the estimation system is developed.The obtained linearization model not only allows the stability to be verified further through Routh criterion,but also reveals the distribution of the characteristic roots,which leads to the clue to optimal PI gains.The theoretical analysis and the resultant design guidelines of the adaptation PI gains are verified through simulation and experiments.展开更多
OBJECTIVE To investigate a new noninvasive method for calculating left ventricular diastolic time constant(Tau) through a continuous-wave aortic regurgitation Doppler spectrum.METHODS According to ultrasound guidance,...OBJECTIVE To investigate a new noninvasive method for calculating left ventricular diastolic time constant(Tau) through a continuous-wave aortic regurgitation Doppler spectrum.METHODS According to ultrasound guidance, twenty-four animal models(beagles) of aortic regurgitation and acute ischemic left ventricular diastolic dysfunction were created. The left ventricular diastolic function was manipulated with dobutamine or esmolol and fifty-nine hemodynamic stages were achieved. Raw audio signals of the continuous-wave Doppler spectra were collected, and new aortic regurgitation Doppler spectra were built after reprocessing by a personal computer. The updating time of the spectral line was 0.3 ms. The new Doppler spectra contour line was automated using MATLAB(MATrix LABoratory, MathWorks, Natick, MA, USA), and two time intervals,(t2–t1) and(t3–t1) were measured on the ascending branch of the aortic regurgitation Doppler spectrum. Then, the two time intervals were substituted into Bai's equations, and Doppler-derived Tau(Tau-D)was resolved and compared with catheter-derived Tau(Tau-c).RESULTS There is no significant difference between Tau-D and Tau-c(45.95 ± 16.90 ms and 46.81 ± 17.31 ms, respectively;P >0.05). Correlation analysis between Tau-c and Tau-D suggested a strong positive relationship(r = 0.97, P = 0.000). A Bland-Altman plot of Tau-c and Tau-D revealed fair agreement.CONCLUSIONS This new calculation method is simple, convenient, and shows a strong positive relationship and fair agreement with the catheter method.展开更多
Rotor time constant is an important parameter for the indirect lleld oraentateO control of mauc- tion motor. Incorrect rotor tittle constant value will cause the flux observer generating a wrong angu- lar orientation ...Rotor time constant is an important parameter for the indirect lleld oraentateO control of mauc- tion motor. Incorrect rotor tittle constant value will cause the flux observer generating a wrong angu- lar orientation of the rotor field. A new approach serves for rotor time constant on-line adaptation by setting the stator current to be zero for a short period. A smooth eorrector is designed to prevent ab- normal detection result from making adaptation. Impact of zero current duration on detection error and rotor speed is analyzed by experiments.展开更多
Planck scale plays a vital role in describing fundamental forces. Space time describes strength of fundamental force. In this paper, Einstein’s general relativity equation has been described in terms of contraction a...Planck scale plays a vital role in describing fundamental forces. Space time describes strength of fundamental force. In this paper, Einstein’s general relativity equation has been described in terms of contraction and expansion forces of space time. According to this, the space time with Planck diameter is a flat space time. This is the only diameter of space time that can be used as signal transformation in special relativity. This space time diameter defines the fundamental force which belongs to that space time. In quantum mechanics, this space time diameter is only the quantum of space which belongs to that particular fundamental force. Einstein’s general relativity equation and Planck parameters of quantum mechanics have been written in terms of equations containing a constant “K”, thus found a new equation for transformation of general relativity space time in to quantum space time. In this process of synchronization, there is a possibility of a new fundamental force between electromagnetic and gravitational forces with Planck length as its space time diameter. It is proposed that dark matter is that fundamental force carrying particle. By grand unification equation with space-time diameter, we found a coupling constant as per standard model “α<sub>s</sub>” for that fundamental force is 1.08 × 10<sup>-23</sup>. Its energy calculated as 113 MeV. A group of experimental scientists reported the energy of dark matter particle as 17 MeV. Thorough review may advance science further.展开更多
The photoplethysmogram(PPG) of a pulse wave,similar in appearance to the arterial blood pressure(ABP) waveform,contains rich information about the cardiovascular system.The decay time constant RC,equal to the product ...The photoplethysmogram(PPG) of a pulse wave,similar in appearance to the arterial blood pressure(ABP) waveform,contains rich information about the cardiovascular system.The decay time constant RC,equal to the product of peripheral resistance R and total arterial compliance C,is a meaningful cardiovascular model parameter in vascular assessment.Using or ameliorating the existing ABP methods does not achieve a satisfactory estimation of RC from the PPG volume pulse(VRC).Thus,a novel non-iterative shape method(NSM) of evaluating VRC is introduced in this paper.The mathematic expression between a novel,readily available morphological parameter called the area difference ratio(ADR) and VRC was established.As it was difficult to calculate VRC from the complicated expression analytically,we recommend estimating it using a piecewise linear interpolation criterion.Also,since the effect of the PPG magnitude is eliminated in the calculation of ADR,precaliberation or normalization is dispensable in the NSM.Results of human experiments indicated that the NSM was computationally efficient,and the simulation experiments confirmed that the NSM was theoretically available for ABP.展开更多
A terminating type MEMS microwave power sensor based on the Seebeck effect and compatible with the GaAs MMIC process is presented.An electrothermal model is introduced to simulate the thermal time constant. An analyti...A terminating type MEMS microwave power sensor based on the Seebeck effect and compatible with the GaAs MMIC process is presented.An electrothermal model is introduced to simulate the thermal time constant. An analytical result,about 160 ms,of the thermal time constant from the non-stationary Fourier heat equations for the structure of the sensor is also given.The sensor measures the microwave power jumping from 15 to 20 dBm at a constant frequency 15 GHz,and the experimental thermal time constant result is 180 ms.The frequency is also changed from 20 to 10 GHz with a constant power 20 dBm,and the result is also 180 ms.Compared with the analytical and experimental results,the model is verified.展开更多
Objective High Energy Photon Source-Test Facility(HEPS-TF)is a pre-research project for the construction of high energy synchrotron radiation source in the 12th five-year plan period.The purpose is to research the key...Objective High Energy Photon Source-Test Facility(HEPS-TF)is a pre-research project for the construction of high energy synchrotron radiation source in the 12th five-year plan period.The purpose is to research the key technology and develop the key equipment of high energy synchrotron radiation source.Superconducting 3W1 magnet is the first self-developed superconducting wiggler magnet in China,and it is also one of the key research topics of HEPS.The author has completed a new digital closed-loop control algorithm for the superconducting 3W1 magnet with large load time constant and the nonlinear characteristics of inductance increasing with current,namely three-branch structure algorithm.In the face of the rapid development of high energy accelerator technology,the application of intelligent technology has become an inevitable development trend in the field of accelerator magnet power supply technology.Although the digital control of accelerator magnet power supply has been widely used,it is the first time to apply the new closed-loop control algorithm to realize fast adjustment and precision tracking in accelerator superconducting magnet power supply in China.Method According to the nonlinear characteristics of inductance and output current of superconducting magnet,a new digital closed-loop control algorithm for the load of superconducting magnet power supply with large time constant is proposed.Conclusion This algorithm is quite different from the traditional algorithm and can attain the independent tracking and adjust-ment of the control target.Finally,by testing the ripple,error and stability of superconducting 3W1 magnet power supply,the correctness,practicability and reliability of power supply system as well as the digital control algorithm are verified.The results provide a new idea for the control of accelerator magnet power supply.展开更多
There are two different models of water flow in soil-plant system, i. e. the linear model and the non-linear model.The linear model is based on an analogy with Ohm’s Law. A difference in water potential is analogous ...There are two different models of water flow in soil-plant system, i. e. the linear model and the non-linear model.The linear model is based on an analogy with Ohm’s Law. A difference in water potential is analogous to the electrical potential difference, and the flow rate analogous to current intensity. Hydraulic resistance R(constant)is defined by the ratio of water potential difference展开更多
In this paper, the stability and bifurcation behaviors of a predator-prey model with the piecewise constant arguments and time delay are investigated. Technical approach is fully based on Jury criterion and bifurcatio...In this paper, the stability and bifurcation behaviors of a predator-prey model with the piecewise constant arguments and time delay are investigated. Technical approach is fully based on Jury criterion and bifurcation theory. The interesting point is that the model will produce two different branches by limiting branch parameters of different intervals. Besides, image simulation is also given.展开更多
A model is presented where the quintessence parameter, w, is related to a time-varying gravitational constant. Assuming a present value of w = -0.98 , we predict a current variation of ?/G = -0.06H0, a value within cu...A model is presented where the quintessence parameter, w, is related to a time-varying gravitational constant. Assuming a present value of w = -0.98 , we predict a current variation of ?/G = -0.06H0, a value within current observational bounds. H0 is Hubble’s parameter, G is Newton’s constant and ? is the derivative of G with respect to time. Thus, G has a cosmic origin, is decreasing with respect to cosmological time, and is proportional to H0, as originally proposed by the Dirac-Jordan hypothesis, albeit at a much slower rate. Within our model, we can explain the cosmological constant fine-tuning problem, the discrepancy between the present very weak value of the cosmological constant, and the much greater vacuum energy found in earlier epochs (we assume a connection exists). To formalize and solidify our model, we give two distinct parametrizations of G with respect to “a”, the cosmic scale parameter. We treat G-1 as an order parameter, which vanishes at high energies;at low temperatures, it reaches a saturation value, a value we are close to today. Our first parametrization for G-1 is motivated by a charging capacitor;the second treats G-1(a) by analogy to a magnetic response, i.e., as a Langevin function. Both parametrizations, even though very distinct, give a remarkably similar tracking behavior for w(a) , but not of the conventional form, w(a) = w0 + wa(1-a) , which can be thought of as only holding over a limited range in “a”. Interestingly, both parametrizations indicate the onset of G formation at a temperature of approximately 7×1021 degrees Kelvin, in contrast to the ΛCDM model where G is taken as a constant all the way back to the Planck temperature, 1.42×1032 degrees Kelvin. At the temperature of formation, we find that G has increased to roughly 4×1020 times its current value. For most of cosmic evolution, however, our variable G model gives results similar to the predictions of the ΛCDM model, except in the very early universe, as we shall demonstrate. In fact, in the limit where w approaches -1, the expression, ?/G , vanishes, and we are left with the concordance model. Within our framework, the emergence of dark energy over matter at a scale of a ≈ 0.5 is that point where G-1 increases noticeably to its current value, G0-1 . This weakening of G to its current value G0 is speculated as the true cause for the observed unanticipated acceleration of the universe.展开更多
Purpose: The cosmic microwave background radiation, CMB, is fundamental to observational cosmology, and is believed to be a remnant from the Big Bang. The CMB, Planck time, t<sub>P</sub>, and the Hubble co...Purpose: The cosmic microwave background radiation, CMB, is fundamental to observational cosmology, and is believed to be a remnant from the Big Bang. The CMB, Planck time, t<sub>P</sub>, and the Hubble constant, H<sub>0</sub>, are important cosmologic constants. The goal is to accurately derive and demonstrate the inter-relationships of the CMB peak spectral radiance frequency, t<sub>P</sub>, and H<sub>0</sub> from neutron and hydrogen quantum data only. Methods: The harmonic neutron hypothesis, HNH, evaluates physical phenomena within a finite consecutive integer and exponential power law harmonic fraction series that are scaled by a fundamental frequency of the neutron as the exponent base. The CMB and the H<sub>0</sub> are derived from a previously published method used to derive t<sub>P</sub>. Their associated integer exponents are respectively +1/2, −3/4, and −128/35. Results: Precise mathematical relationships of these three constants are demonstrated. All of the derived values are within their known observational values. The derived and known values are: ν<sub>CMB</sub>, 160.041737 (06) × 10<sup>9</sup> Hz, ~160 × 10<sup>9</sup> Hz;2.72519 K, 2.72548 ± 0.00057 K, H<sub>0</sub> 2.29726666 (11) × 10<sup>−18</sup> s<sup>−1</sup>, ~2.3 × 10<sup>−18</sup> s<sup>−1</sup>;and t<sub>P</sub> 5.3911418 (3) × 10<sup>−44</sup> s, 5.39106 (32) × 10<sup>−44</sup> s. Conclusion: The cosmic fundamental constants t<sub>P</sub>, H<sub>0</sub>, and CMB are mathematically inter-related constants all defined by gravity. They are also directly derivable from the quantum properties of the neutron and hydrogen within a harmonic power law.展开更多
A high accuracy Higgs boson, H0, is an important physical constant. The Higgs boson is associated with the property of mass related to broken symmetry in the Standard Model. The H0 mass cannot be derived by the Standa...A high accuracy Higgs boson, H0, is an important physical constant. The Higgs boson is associated with the property of mass related to broken symmetry in the Standard Model. The H0 mass cannot be derived by the Standard Model. The goal of this work is to derive and predict the mass of H0 from the subatomic data of the frequency equivalents of the neutron, electron, Bohr radius, and the ionization energy of hydrogen. H0’s close relationships to the fine structure constant, α, the down quark, and Planck time, tP are demonstrated. The methods of the harmonic neutron hypothesis introduced in 2009 were utilized. It assumes that the fundamental constants as frequency equivalents represent a classic unified harmonic system where each physical constant is associated with a classic harmonic integer fraction. It has been demonstrated that the sum exponent of a harmonic integer fraction, and a small derived linear δ value of the annhilation frequency of the neutron, vn, 2.2718591 × 1023 Hz, (vns) as a dimensionless coupling constant represent many physical constants as frequency equivalents. This is a natural unit system. The harmonic integer fraction series is 1/±n, and 1 ± 1/n for n equals 1 to ∞. The H0 is empirically and logically is associated with harmonic fractions, 1/11 and 1 + 1/11. α-1 is associated with 11. α-1 is a free space scaling constant for the electromagnetic force so it is logical that 11 should also have a pair, but for a free space mass constant. Also there should be a harmonic faction pair for the down quark, 1 - 1/11, just as there is pairing of the up quark, 1 - 1/10, and top quark, 1 + 1/10. The harmonic neutron hypothesis has published a method deriving a high accuracy Planck time, tP from the same limited subatomic data. The δ line for H0 should be closely associated with tP since they both are related to mass. The preferred derived value related to tP2 is 125.596808 GeV/c2. A less attractive derived value is 125.120961 GeV/c2 from the weak force factors only. The experimental CMS and Atlas value ranges are 125.03+0.26+0.13-0.27-0.15 and 125.36±0.37±0.18 GeV/c2. Empirically the H0 δ line is closely related to the same factors of the tP δ line, but with inverse sign of the slope. The H0 completes the paring of a free space constant for mass, the down quark, and an inverse sign δ line factors with tP. It is possible to accurately derive the mass of H0 from subatomic physical data. The model demonstrates that H0 is closely associated with α, the down quark, and tP. This prediction can be scrutinized in the future to see if it is accurate. The model has already published accurate predictions of the masses of the quarks.展开更多
We show that, when measuring the Hubble constant by starting the evaluation from the time of the big bang era, the effect of time dilation results in a decrease in the value of the Hubble constant. But when evaluating...We show that, when measuring the Hubble constant by starting the evaluation from the time of the big bang era, the effect of time dilation results in a decrease in the value of the Hubble constant. But when evaluating the Hubble constant by starting the evaluation from the present time, the effect of time dilation results in an increase in the value of the Hubble constant. To elucidate the process, the time dilation is calculated both directly and through Schwarzschild solution of the Einstein equation for the gravitational time dilation. It is concluded that both measured values are valid but because of time dilation, different starting times for the evaluation of the Hubble constant have resulted in different measured values for the Hubble constant.展开更多
We take the results where we reduplicate the Book “Dark Energy” by M. Li, X-D. Li, and Y. Wang, zero-point energy calculation, as folded in with the Klauder methodology, as given in a prior publication. From there w...We take the results where we reduplicate the Book “Dark Energy” by M. Li, X-D. Li, and Y. Wang, zero-point energy calculation, as folded in with the Klauder methodology, as given in a prior publication. From there we first access the Rosen solution to a mini universe energy to ascertain an energy value of t, the pre-inflationary near singularity, then access what would be needed as to inject information into our universe. We then close with an argument by Narilkar as to a quantum bound on the Einstein-Hilbert action integral, so as to obtain quantum Gravity. Narlikar omits the cosmological constant. We keep it in, for our overall conclusion about the cosmological constant and its relevance to Quantum gravity.展开更多
A new adaptive filtering principle based on capability control and semi-blind method is presented. A new semi-blind space-time equalizer based on constant modulus characteristic and structure risk minimum (SRM) crit...A new adaptive filtering principle based on capability control and semi-blind method is presented. A new semi-blind space-time equalizer based on constant modulus characteristic and structure risk minimum (SRM) criterion is also proposed. The equalizer sufficiently exploits the learning information of communication signals by using the structure information of filter itself through capability control technique. Namely, it maximizes the amount of learning information to im- prove filter tracking performance. Simulations are carried out and the result is compared with that of typical recursive least squares space-time equalizer (RLS-STE) and constant modulus semi-blind space-time equalizer ( CM-SB-STE ). The results show that, even if with insufficient training data, the SRM constant modulus semi-blind space-time equalizer (SCM-SB-STE) keeps good tracking per- formance, showing promises in mobile wireless communications.展开更多
The following is a rendition of what was presented by the author, September 11, 2020 in the DE section of that conference. The topics, while not original, are in strict fidelity with the topics the author was allowed ...The following is a rendition of what was presented by the author, September 11, 2020 in the DE section of that conference. The topics, while not original, are in strict fidelity with the topics the author was allowed to present in ICRANET Zeldovich 4, 2020. We present a history of the evolution of the cosmological constant “issue” starting with its introduction by Einstein for a static universe, which did not work out because his static universe solution to the Ricci Scalar problem, and GR was and is UNSTABLE. Another model of the cosmological constant has a radius of the Universe specified which is proportional to one over the square root of the cosmological constant, whereas our idea is to use the matching of two spacetime first integrals, for isolating a nonperturbative cosmological constant solution right at the surface of the start of expansion of the universe, <i>i.e.</i> a phenomenological solution to the cosmological constant involves scaling of a radius of the PRESENT universe. Our presented idea is to instead solve the Cosmological constant at the surface of the initial space-time bubble, using the initially derived time step, delta t, as input for the Cosmological constant. As it is, the Zeldovich 4 Section I was in was for Dark Energy, so in solving the initial value of the Cosmological constant, I am giving backing to one of the models of DE as to why the Universe reaccelerates one billion years ago. We conclude as to a reference to a multiverse generalization of Penrose Cyclic Conformal Cosmology as input into the initial nonsingular space-time bubble.展开更多
For the last hundred years, the existence and the value of the cosmological constant Λ has been a great enigma. So far, any theoretical model has failed to predict the value of Λ by several orders of magnitude. We h...For the last hundred years, the existence and the value of the cosmological constant Λ has been a great enigma. So far, any theoretical model has failed to predict the value of Λ by several orders of magnitude. We here offer a solution to the cosmological constant problem by extending the Einstein-Friedmann equations by one additional time dimension. Solving these equations, we find that the Universe is flat on a global scale and that the cosmological constant lies between 10<sup>-90</sup> m<sup>-2</sup> and 10<sup>-51</sup> m<sup>-2</sup> which is in range observed by experiments. It also proposes a mean to explain the Planck length and to mitigate the singularity at the Big Bang.展开更多
We reduplicate the Book “Dark Energy” by M. Li, X-D. Li, and Y. Wang, given zero-point energy calculation with an unexpected “length” added to the “width” of a graviton wave just prior to specifying the creation...We reduplicate the Book “Dark Energy” by M. Li, X-D. Li, and Y. Wang, given zero-point energy calculation with an unexpected “length” added to the “width” of a graviton wave just prior to specifying the creation of “gravitons”, using the Rosen and Israelit model of a nonsingular universe. In doing so we are in addition to obtaining a wavelength 10<sup>30</sup> times greater than Planck’s length so we can calculate DE, may be able to with the help of the Rosen and Israelit model have a first approximation as to the arrow of time, and a universe with massive gravity. We have left the particulars of the nonsingular starting point undefined but state that the Rosen and Israelit model postulates initial temperatures of 10<sup>-180</sup> Kelvin and also a value of about Planck temperature, at 10<sup>-3</sup> centimeters radii value which may satisfy initial conditions asked by t’Hooft for describing an arrow of time. A key assumption is that the DE is formed at 10<sup>-3</sup> cm, after an expansion of 10<sup>30</sup> times in radii, from the Planck length radius nonsingular starting point. The given starting point for DE in this set of assumptions is where there is a change in the cosmic acceleration, to a zero value, according to Rosen and Israel, with time <i>t</i> = 1.31 times 10<sup>-42</sup> seconds. That may be where we may specify a potential magnitude, <i>V</i>, which has ties into inflaton physics. The particulars of the model from Rosen and Israelit allow a solution to be found, without discussion of where that nonsingular starting point came from, a point the author found in need of drastic remedies and fixes.展开更多
文摘The theory for measuring the time constant of thermocouple was introduced, and the method for measuring the time constant of NANMAC thermocouple by using dynamic calibration system of transient surface temperature sensor was proposed. In this system, static and dynamic calibrations were conducted for infrared detectors and thermocouples, and then both temperature-time curves were obtained. Since the frequency response of infrared detector is superior to that of calibrat- ed thermocouple, the values measured by infrared detectors are taken as true values. Through dividing the values measured with thermocouples by those with infrared detectors, a normalized curve was obtained, based on which the time constant of thermocouple was measured. With this method, the experiments were carried out with NANMAC thermocouple to obtain its time constant. The results show that the method for measuring the time constant is feasible and the dynamic calibration of thermocouples can be achieved at microsecond and millisecond level. This research has a certain reference value for research and application of NANMAC thermocouple temperature sensor.
文摘q-axis rotor flux can be chosen to form a model reference adaptive system(MRAS)updating rotor time constant online in induction motor drives.This paper presents a stability analysis of such a system with Popov’s hyperstability concept and small-signal linearization technique.At first,the stability of q-axis rotor flux based MRAS is proven with Popov’s Hyperstability theory.Then,to find out the guidelines for optimally designing the coefficients in the PI controller,acting as the adaption mechanism in the MRAS,small-signal model of the estimation system is developed.The obtained linearization model not only allows the stability to be verified further through Routh criterion,but also reveals the distribution of the characteristic roots,which leads to the clue to optimal PI gains.The theoretical analysis and the resultant design guidelines of the adaptation PI gains are verified through simulation and experiments.
基金supported by the National Natural Science Foundation of China (No.81771833)the Beijing Natural Science Foundation (No.7172209)。
文摘OBJECTIVE To investigate a new noninvasive method for calculating left ventricular diastolic time constant(Tau) through a continuous-wave aortic regurgitation Doppler spectrum.METHODS According to ultrasound guidance, twenty-four animal models(beagles) of aortic regurgitation and acute ischemic left ventricular diastolic dysfunction were created. The left ventricular diastolic function was manipulated with dobutamine or esmolol and fifty-nine hemodynamic stages were achieved. Raw audio signals of the continuous-wave Doppler spectra were collected, and new aortic regurgitation Doppler spectra were built after reprocessing by a personal computer. The updating time of the spectral line was 0.3 ms. The new Doppler spectra contour line was automated using MATLAB(MATrix LABoratory, MathWorks, Natick, MA, USA), and two time intervals,(t2–t1) and(t3–t1) were measured on the ascending branch of the aortic regurgitation Doppler spectrum. Then, the two time intervals were substituted into Bai's equations, and Doppler-derived Tau(Tau-D)was resolved and compared with catheter-derived Tau(Tau-c).RESULTS There is no significant difference between Tau-D and Tau-c(45.95 ± 16.90 ms and 46.81 ± 17.31 ms, respectively;P >0.05). Correlation analysis between Tau-c and Tau-D suggested a strong positive relationship(r = 0.97, P = 0.000). A Bland-Altman plot of Tau-c and Tau-D revealed fair agreement.CONCLUSIONS This new calculation method is simple, convenient, and shows a strong positive relationship and fair agreement with the catheter method.
基金Supported by the National Natural Science Foundation of China(No.51276016)the Fundamental Research Funds for the Central University(No.FRF-TP-12-059A)
文摘Rotor time constant is an important parameter for the indirect lleld oraentateO control of mauc- tion motor. Incorrect rotor tittle constant value will cause the flux observer generating a wrong angu- lar orientation of the rotor field. A new approach serves for rotor time constant on-line adaptation by setting the stator current to be zero for a short period. A smooth eorrector is designed to prevent ab- normal detection result from making adaptation. Impact of zero current duration on detection error and rotor speed is analyzed by experiments.
文摘Planck scale plays a vital role in describing fundamental forces. Space time describes strength of fundamental force. In this paper, Einstein’s general relativity equation has been described in terms of contraction and expansion forces of space time. According to this, the space time with Planck diameter is a flat space time. This is the only diameter of space time that can be used as signal transformation in special relativity. This space time diameter defines the fundamental force which belongs to that space time. In quantum mechanics, this space time diameter is only the quantum of space which belongs to that particular fundamental force. Einstein’s general relativity equation and Planck parameters of quantum mechanics have been written in terms of equations containing a constant “K”, thus found a new equation for transformation of general relativity space time in to quantum space time. In this process of synchronization, there is a possibility of a new fundamental force between electromagnetic and gravitational forces with Planck length as its space time diameter. It is proposed that dark matter is that fundamental force carrying particle. By grand unification equation with space-time diameter, we found a coupling constant as per standard model “α<sub>s</sub>” for that fundamental force is 1.08 × 10<sup>-23</sup>. Its energy calculated as 113 MeV. A group of experimental scientists reported the energy of dark matter particle as 17 MeV. Thorough review may advance science further.
基金Project (No.81070885) supported by the National Natural Science Foundation of China
文摘The photoplethysmogram(PPG) of a pulse wave,similar in appearance to the arterial blood pressure(ABP) waveform,contains rich information about the cardiovascular system.The decay time constant RC,equal to the product of peripheral resistance R and total arterial compliance C,is a meaningful cardiovascular model parameter in vascular assessment.Using or ameliorating the existing ABP methods does not achieve a satisfactory estimation of RC from the PPG volume pulse(VRC).Thus,a novel non-iterative shape method(NSM) of evaluating VRC is introduced in this paper.The mathematic expression between a novel,readily available morphological parameter called the area difference ratio(ADR) and VRC was established.As it was difficult to calculate VRC from the complicated expression analytically,we recommend estimating it using a piecewise linear interpolation criterion.Also,since the effect of the PPG magnitude is eliminated in the calculation of ADR,precaliberation or normalization is dispensable in the NSM.Results of human experiments indicated that the NSM was computationally efficient,and the simulation experiments confirmed that the NSM was theoretically available for ABP.
基金supported by the National Natural Science Foundation of China(No.60676043)the National High Technology Research and Development Program of China(No.2007AA04Z328)
文摘A terminating type MEMS microwave power sensor based on the Seebeck effect and compatible with the GaAs MMIC process is presented.An electrothermal model is introduced to simulate the thermal time constant. An analytical result,about 160 ms,of the thermal time constant from the non-stationary Fourier heat equations for the structure of the sensor is also given.The sensor measures the microwave power jumping from 15 to 20 dBm at a constant frequency 15 GHz,and the experimental thermal time constant result is 180 ms.The frequency is also changed from 20 to 10 GHz with a constant power 20 dBm,and the result is also 180 ms.Compared with the analytical and experimental results,the model is verified.
基金the Accelerator Centre of Insti-tute of High Energy Physics for financial support
文摘Objective High Energy Photon Source-Test Facility(HEPS-TF)is a pre-research project for the construction of high energy synchrotron radiation source in the 12th five-year plan period.The purpose is to research the key technology and develop the key equipment of high energy synchrotron radiation source.Superconducting 3W1 magnet is the first self-developed superconducting wiggler magnet in China,and it is also one of the key research topics of HEPS.The author has completed a new digital closed-loop control algorithm for the superconducting 3W1 magnet with large load time constant and the nonlinear characteristics of inductance increasing with current,namely three-branch structure algorithm.In the face of the rapid development of high energy accelerator technology,the application of intelligent technology has become an inevitable development trend in the field of accelerator magnet power supply technology.Although the digital control of accelerator magnet power supply has been widely used,it is the first time to apply the new closed-loop control algorithm to realize fast adjustment and precision tracking in accelerator superconducting magnet power supply in China.Method According to the nonlinear characteristics of inductance and output current of superconducting magnet,a new digital closed-loop control algorithm for the load of superconducting magnet power supply with large time constant is proposed.Conclusion This algorithm is quite different from the traditional algorithm and can attain the independent tracking and adjust-ment of the control target.Finally,by testing the ripple,error and stability of superconducting 3W1 magnet power supply,the correctness,practicability and reliability of power supply system as well as the digital control algorithm are verified.The results provide a new idea for the control of accelerator magnet power supply.
基金Project supported by Youth Research Foundation of Academia Sinica, and carried out in LMCP of Nanjing Institute of Soil Science, Academia Sinica.
文摘There are two different models of water flow in soil-plant system, i. e. the linear model and the non-linear model.The linear model is based on an analogy with Ohm’s Law. A difference in water potential is analogous to the electrical potential difference, and the flow rate analogous to current intensity. Hydraulic resistance R(constant)is defined by the ratio of water potential difference
基金supported by Beijing Higher Education Young Elite Teacher(YETP0458)
文摘In this paper, the stability and bifurcation behaviors of a predator-prey model with the piecewise constant arguments and time delay are investigated. Technical approach is fully based on Jury criterion and bifurcation theory. The interesting point is that the model will produce two different branches by limiting branch parameters of different intervals. Besides, image simulation is also given.
文摘A model is presented where the quintessence parameter, w, is related to a time-varying gravitational constant. Assuming a present value of w = -0.98 , we predict a current variation of ?/G = -0.06H0, a value within current observational bounds. H0 is Hubble’s parameter, G is Newton’s constant and ? is the derivative of G with respect to time. Thus, G has a cosmic origin, is decreasing with respect to cosmological time, and is proportional to H0, as originally proposed by the Dirac-Jordan hypothesis, albeit at a much slower rate. Within our model, we can explain the cosmological constant fine-tuning problem, the discrepancy between the present very weak value of the cosmological constant, and the much greater vacuum energy found in earlier epochs (we assume a connection exists). To formalize and solidify our model, we give two distinct parametrizations of G with respect to “a”, the cosmic scale parameter. We treat G-1 as an order parameter, which vanishes at high energies;at low temperatures, it reaches a saturation value, a value we are close to today. Our first parametrization for G-1 is motivated by a charging capacitor;the second treats G-1(a) by analogy to a magnetic response, i.e., as a Langevin function. Both parametrizations, even though very distinct, give a remarkably similar tracking behavior for w(a) , but not of the conventional form, w(a) = w0 + wa(1-a) , which can be thought of as only holding over a limited range in “a”. Interestingly, both parametrizations indicate the onset of G formation at a temperature of approximately 7×1021 degrees Kelvin, in contrast to the ΛCDM model where G is taken as a constant all the way back to the Planck temperature, 1.42×1032 degrees Kelvin. At the temperature of formation, we find that G has increased to roughly 4×1020 times its current value. For most of cosmic evolution, however, our variable G model gives results similar to the predictions of the ΛCDM model, except in the very early universe, as we shall demonstrate. In fact, in the limit where w approaches -1, the expression, ?/G , vanishes, and we are left with the concordance model. Within our framework, the emergence of dark energy over matter at a scale of a ≈ 0.5 is that point where G-1 increases noticeably to its current value, G0-1 . This weakening of G to its current value G0 is speculated as the true cause for the observed unanticipated acceleration of the universe.
文摘Purpose: The cosmic microwave background radiation, CMB, is fundamental to observational cosmology, and is believed to be a remnant from the Big Bang. The CMB, Planck time, t<sub>P</sub>, and the Hubble constant, H<sub>0</sub>, are important cosmologic constants. The goal is to accurately derive and demonstrate the inter-relationships of the CMB peak spectral radiance frequency, t<sub>P</sub>, and H<sub>0</sub> from neutron and hydrogen quantum data only. Methods: The harmonic neutron hypothesis, HNH, evaluates physical phenomena within a finite consecutive integer and exponential power law harmonic fraction series that are scaled by a fundamental frequency of the neutron as the exponent base. The CMB and the H<sub>0</sub> are derived from a previously published method used to derive t<sub>P</sub>. Their associated integer exponents are respectively +1/2, −3/4, and −128/35. Results: Precise mathematical relationships of these three constants are demonstrated. All of the derived values are within their known observational values. The derived and known values are: ν<sub>CMB</sub>, 160.041737 (06) × 10<sup>9</sup> Hz, ~160 × 10<sup>9</sup> Hz;2.72519 K, 2.72548 ± 0.00057 K, H<sub>0</sub> 2.29726666 (11) × 10<sup>−18</sup> s<sup>−1</sup>, ~2.3 × 10<sup>−18</sup> s<sup>−1</sup>;and t<sub>P</sub> 5.3911418 (3) × 10<sup>−44</sup> s, 5.39106 (32) × 10<sup>−44</sup> s. Conclusion: The cosmic fundamental constants t<sub>P</sub>, H<sub>0</sub>, and CMB are mathematically inter-related constants all defined by gravity. They are also directly derivable from the quantum properties of the neutron and hydrogen within a harmonic power law.
文摘A high accuracy Higgs boson, H0, is an important physical constant. The Higgs boson is associated with the property of mass related to broken symmetry in the Standard Model. The H0 mass cannot be derived by the Standard Model. The goal of this work is to derive and predict the mass of H0 from the subatomic data of the frequency equivalents of the neutron, electron, Bohr radius, and the ionization energy of hydrogen. H0’s close relationships to the fine structure constant, α, the down quark, and Planck time, tP are demonstrated. The methods of the harmonic neutron hypothesis introduced in 2009 were utilized. It assumes that the fundamental constants as frequency equivalents represent a classic unified harmonic system where each physical constant is associated with a classic harmonic integer fraction. It has been demonstrated that the sum exponent of a harmonic integer fraction, and a small derived linear δ value of the annhilation frequency of the neutron, vn, 2.2718591 × 1023 Hz, (vns) as a dimensionless coupling constant represent many physical constants as frequency equivalents. This is a natural unit system. The harmonic integer fraction series is 1/±n, and 1 ± 1/n for n equals 1 to ∞. The H0 is empirically and logically is associated with harmonic fractions, 1/11 and 1 + 1/11. α-1 is associated with 11. α-1 is a free space scaling constant for the electromagnetic force so it is logical that 11 should also have a pair, but for a free space mass constant. Also there should be a harmonic faction pair for the down quark, 1 - 1/11, just as there is pairing of the up quark, 1 - 1/10, and top quark, 1 + 1/10. The harmonic neutron hypothesis has published a method deriving a high accuracy Planck time, tP from the same limited subatomic data. The δ line for H0 should be closely associated with tP since they both are related to mass. The preferred derived value related to tP2 is 125.596808 GeV/c2. A less attractive derived value is 125.120961 GeV/c2 from the weak force factors only. The experimental CMS and Atlas value ranges are 125.03+0.26+0.13-0.27-0.15 and 125.36±0.37±0.18 GeV/c2. Empirically the H0 δ line is closely related to the same factors of the tP δ line, but with inverse sign of the slope. The H0 completes the paring of a free space constant for mass, the down quark, and an inverse sign δ line factors with tP. It is possible to accurately derive the mass of H0 from subatomic physical data. The model demonstrates that H0 is closely associated with α, the down quark, and tP. This prediction can be scrutinized in the future to see if it is accurate. The model has already published accurate predictions of the masses of the quarks.
文摘We show that, when measuring the Hubble constant by starting the evaluation from the time of the big bang era, the effect of time dilation results in a decrease in the value of the Hubble constant. But when evaluating the Hubble constant by starting the evaluation from the present time, the effect of time dilation results in an increase in the value of the Hubble constant. To elucidate the process, the time dilation is calculated both directly and through Schwarzschild solution of the Einstein equation for the gravitational time dilation. It is concluded that both measured values are valid but because of time dilation, different starting times for the evaluation of the Hubble constant have resulted in different measured values for the Hubble constant.
文摘We take the results where we reduplicate the Book “Dark Energy” by M. Li, X-D. Li, and Y. Wang, zero-point energy calculation, as folded in with the Klauder methodology, as given in a prior publication. From there we first access the Rosen solution to a mini universe energy to ascertain an energy value of t, the pre-inflationary near singularity, then access what would be needed as to inject information into our universe. We then close with an argument by Narilkar as to a quantum bound on the Einstein-Hilbert action integral, so as to obtain quantum Gravity. Narlikar omits the cosmological constant. We keep it in, for our overall conclusion about the cosmological constant and its relevance to Quantum gravity.
基金Supported by the National Natural Science Foundation of China(60772056)
文摘A new adaptive filtering principle based on capability control and semi-blind method is presented. A new semi-blind space-time equalizer based on constant modulus characteristic and structure risk minimum (SRM) criterion is also proposed. The equalizer sufficiently exploits the learning information of communication signals by using the structure information of filter itself through capability control technique. Namely, it maximizes the amount of learning information to im- prove filter tracking performance. Simulations are carried out and the result is compared with that of typical recursive least squares space-time equalizer (RLS-STE) and constant modulus semi-blind space-time equalizer ( CM-SB-STE ). The results show that, even if with insufficient training data, the SRM constant modulus semi-blind space-time equalizer (SCM-SB-STE) keeps good tracking per- formance, showing promises in mobile wireless communications.
文摘The following is a rendition of what was presented by the author, September 11, 2020 in the DE section of that conference. The topics, while not original, are in strict fidelity with the topics the author was allowed to present in ICRANET Zeldovich 4, 2020. We present a history of the evolution of the cosmological constant “issue” starting with its introduction by Einstein for a static universe, which did not work out because his static universe solution to the Ricci Scalar problem, and GR was and is UNSTABLE. Another model of the cosmological constant has a radius of the Universe specified which is proportional to one over the square root of the cosmological constant, whereas our idea is to use the matching of two spacetime first integrals, for isolating a nonperturbative cosmological constant solution right at the surface of the start of expansion of the universe, <i>i.e.</i> a phenomenological solution to the cosmological constant involves scaling of a radius of the PRESENT universe. Our presented idea is to instead solve the Cosmological constant at the surface of the initial space-time bubble, using the initially derived time step, delta t, as input for the Cosmological constant. As it is, the Zeldovich 4 Section I was in was for Dark Energy, so in solving the initial value of the Cosmological constant, I am giving backing to one of the models of DE as to why the Universe reaccelerates one billion years ago. We conclude as to a reference to a multiverse generalization of Penrose Cyclic Conformal Cosmology as input into the initial nonsingular space-time bubble.
文摘For the last hundred years, the existence and the value of the cosmological constant Λ has been a great enigma. So far, any theoretical model has failed to predict the value of Λ by several orders of magnitude. We here offer a solution to the cosmological constant problem by extending the Einstein-Friedmann equations by one additional time dimension. Solving these equations, we find that the Universe is flat on a global scale and that the cosmological constant lies between 10<sup>-90</sup> m<sup>-2</sup> and 10<sup>-51</sup> m<sup>-2</sup> which is in range observed by experiments. It also proposes a mean to explain the Planck length and to mitigate the singularity at the Big Bang.
文摘We reduplicate the Book “Dark Energy” by M. Li, X-D. Li, and Y. Wang, given zero-point energy calculation with an unexpected “length” added to the “width” of a graviton wave just prior to specifying the creation of “gravitons”, using the Rosen and Israelit model of a nonsingular universe. In doing so we are in addition to obtaining a wavelength 10<sup>30</sup> times greater than Planck’s length so we can calculate DE, may be able to with the help of the Rosen and Israelit model have a first approximation as to the arrow of time, and a universe with massive gravity. We have left the particulars of the nonsingular starting point undefined but state that the Rosen and Israelit model postulates initial temperatures of 10<sup>-180</sup> Kelvin and also a value of about Planck temperature, at 10<sup>-3</sup> centimeters radii value which may satisfy initial conditions asked by t’Hooft for describing an arrow of time. A key assumption is that the DE is formed at 10<sup>-3</sup> cm, after an expansion of 10<sup>30</sup> times in radii, from the Planck length radius nonsingular starting point. The given starting point for DE in this set of assumptions is where there is a change in the cosmic acceleration, to a zero value, according to Rosen and Israel, with time <i>t</i> = 1.31 times 10<sup>-42</sup> seconds. That may be where we may specify a potential magnitude, <i>V</i>, which has ties into inflaton physics. The particulars of the model from Rosen and Israelit allow a solution to be found, without discussion of where that nonsingular starting point came from, a point the author found in need of drastic remedies and fixes.