The phonon density of states of YBa2Cu3O6.92 is obtained with the method of Fourier decon-volution and Tikhonov-s regularization technique from the experimental specific heat data. The result is compared with that of ...The phonon density of states of YBa2Cu3O6.92 is obtained with the method of Fourier decon-volution and Tikhonov-s regularization technique from the experimental specific heat data. The result is compared with that of neutron inelastic scattering.展开更多
In this paper, we present a simple and fast spectra inversion method to reconstruct the temperature distribution along single fiber Bragg grating （FBC） temperature sensor. This is a fully distributed sensing method ...In this paper, we present a simple and fast spectra inversion method to reconstruct the temperature distribution along single fiber Bragg grating （FBC） temperature sensor. This is a fully distributed sensing method based on the simulated annealing evolutionary （SAE） algorithm. Several modifications are made to improve the algorithm efficiency, including choosing the most superior chromosome, setting up the boundary of every gene according to the density of resonance peaks of the reflection spectrum, and dynamically modifying the boundary with the algorithm running. Numerical simulation results show that both the convergence rate and the fluctuation are significantly improved. A high spat-ial temperature resolution of 0.25 mm has been achieved at the time cost of 86 s.展开更多
It is interesting to maximize the amount of information we can obtain from one experiment on a single sample. In obtaining all the thermodynamic properties of some materials from their experimental heat capacity data ...It is interesting to maximize the amount of information we can obtain from one experiment on a single sample. In obtaining all the thermodynamic properties of some materials from their experimental heat capacity data only, we aim to get the tempera- ture-independent energy spectrum. However, all the practical measured energy spectra depend on the temperature of experi- ments. One promising method to obtain the temperature-independent energy spectrum is to solve the so-called specific heat-phonon spectrum inversion （SPI） problem. Here we show, by developing a new practical solution method of SPI, the phonon spectrum of the negative thermal expansion material ZrW208 is obtained. This phonon spectrum is tempera- ture-independent and almost method independent. Hence all the thermodynamic properties of ZrW208, such as thermodynamic potential, entropy, Helmholtz free energy, etc. are obtained by heat capacity only.展开更多
文摘The phonon density of states of YBa2Cu3O6.92 is obtained with the method of Fourier decon-volution and Tikhonov-s regularization technique from the experimental specific heat data. The result is compared with that of neutron inelastic scattering.
基金Project supported by the Development Foundation of the Education Commission of Shanghai Municipality (Grant No.2008CG47)the Cultivation Foundation of the Key Scientific and Technical Innovation Project (Grant No.708041)+2 种基金the Research Foundation for the Doctoral Program of Higher Education Ministry of Education of China (Grant No.20093108120017)the Shanghai Leading Academic Discipline Project (Grant No.S30108)the Natural Science Foundation of Shanghai Municipality (Grant No.09ZR1412200)
文摘In this paper, we present a simple and fast spectra inversion method to reconstruct the temperature distribution along single fiber Bragg grating （FBC） temperature sensor. This is a fully distributed sensing method based on the simulated annealing evolutionary （SAE） algorithm. Several modifications are made to improve the algorithm efficiency, including choosing the most superior chromosome, setting up the boundary of every gene according to the density of resonance peaks of the reflection spectrum, and dynamically modifying the boundary with the algorithm running. Numerical simulation results show that both the convergence rate and the fluctuation are significantly improved. A high spat-ial temperature resolution of 0.25 mm has been achieved at the time cost of 86 s.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10675031,10375012 and 19975009)the Department of Education of Zhejiang Province (Grant No. Y200906911)
文摘It is interesting to maximize the amount of information we can obtain from one experiment on a single sample. In obtaining all the thermodynamic properties of some materials from their experimental heat capacity data only, we aim to get the tempera- ture-independent energy spectrum. However, all the practical measured energy spectra depend on the temperature of experi- ments. One promising method to obtain the temperature-independent energy spectrum is to solve the so-called specific heat-phonon spectrum inversion （SPI） problem. Here we show, by developing a new practical solution method of SPI, the phonon spectrum of the negative thermal expansion material ZrW208 is obtained. This phonon spectrum is tempera- ture-independent and almost method independent. Hence all the thermodynamic properties of ZrW208, such as thermodynamic potential, entropy, Helmholtz free energy, etc. are obtained by heat capacity only.
