The molecular structure of liquid water has been an outstanding issue for many years. The identification of free -OH holds the key in differentiating structure models for liquid water. By analyzing the relative change...The molecular structure of liquid water has been an outstanding issue for many years. The identification of free -OH holds the key in differentiating structure models for liquid water. By analyzing the relative changes of the intensity and depolarization ratio in temperature dependent Raman spectra, the occurrence of free -OH in liquid water is unambiguously de- termined. Furthermore, upon the increase of temperature from 5 ~C to 85 ~C, the structure of liquid water undergoes significant change, but the relative proportion of free -OH is con- siderably small and remains almost unchanged. This implies that the breaking of hydrogen bond from the tetrahedral structure prefers to The energetic favoring of the structural change experiments. occur at the site of the hydrogen acceptor. for liquid water is thus clearly revealed from展开更多
We firstly detected the Earth's free toroidal oscillations excited by three large earthquakes in Japan,2011,Chile,2010 and Indonesia,2005 from the observed data of the JCZ-1 seismometer at Wuhan Seismic Station. T...We firstly detected the Earth's free toroidal oscillations excited by three large earthquakes in Japan,2011,Chile,2010 and Indonesia,2005 from the observed data of the JCZ-1 seismometer at Wuhan Seismic Station. The eigenperiods of basic modes (0T2 - 0T67 ) and first modes (1T2 ~ 1T50 ) were detected,and their error ratios were less than 0. 5% by comparing the observed eigenvalues with the theoretical eigenvalues in PREM. We supplemented some modes- 0T11,0T15 , 0T19 , 1T4 , 1T5 and 1T14 ,which were not mentioned in PREM,and also observed the spectral line multi-peak phenomenon from 0T2, 0T6 , 0T7 and 0T8 . These results show that the JCZ-1 seismometer is able to precisely observe the Earth's long period toroidal free oscillations.展开更多
This research uses a theoretical conceptual method based on Chantal Mouffe's Radical Democracy which blended with Derrida's deconstruction thesis about "democracy to come" to reach findings on the state of South A...This research uses a theoretical conceptual method based on Chantal Mouffe's Radical Democracy which blended with Derrida's deconstruction thesis about "democracy to come" to reach findings on the state of South Africa's media freedom landscape. The method is contained in the conceptual framework. The article provides the constitutional legal landscape--or the overarching laws of the land--and the co-regulatory framework within which journalists work. There are four research explications: the Protection of State Information Bill (dubbed the Secrecy Bill), a painting of the president and Freedom of Expression, an arson attack on a community radio station and finally, the death of a photojournalist at the hands of police. The argument here is that the death, the arson attack, the Secrecy Bill, and the shut-down of dissent during the exhibition of the painting of the president all undermine democracy and signify significant closures for the media in the now 20-year-old post-apartheid South Africa. The analysis and reflections will be framed within theories of radical democracy, which argue for more fights and contestations and more voices from the margins in order to deepen democracy, rather than rational consensus which closes the spaces for greater plurality.展开更多
By using the digital observations of the pendulum tiltmeter, water tube tiltmeter,extensometer and volumetric strainmeter at Huzhou station and with the power spectrum density estimation method,we acquired the_0S_5-_0...By using the digital observations of the pendulum tiltmeter, water tube tiltmeter,extensometer and volumetric strainmeter at Huzhou station and with the power spectrum density estimation method,we acquired the_0S_5-_0S_50 fundamental sphere free oscillations caused by the Japan earthquake on March 11,2011,then compared it with the PREM model. The relative errors are mostly bigger than 1.2‰. The extensometer and volume strainmeter can clearly detect _0S_2,_0S_3and_0S_4,which are closely related to the deep structure and earth's interior.展开更多
The rapid transition between spherical and γ-soft shapes in Zn isotopes in the mass A 70 region,is analyzed using excitation spectra and collective wave functions obtained by diagonalization of a five-dimensional Ham...The rapid transition between spherical and γ-soft shapes in Zn isotopes in the mass A 70 region,is analyzed using excitation spectra and collective wave functions obtained by diagonalization of a five-dimensional Hamiltonian for quadrupole vibrational and rotational degrees of freedom,with parameters determined by constrained self-consistent relativistic mean-field calculations for triaxial shapes.The microscopic potential energy surfaces,together with the characteristic collective observables,illustrate a rapid transition from near spherical shape at the N = 40 subshell,to γ-soft deformed shapes for lighter isotopes.The calculated spectra display fingerprints of a second-order shape phase transition that can be approximately described by the E(5) analytic solution.展开更多
The development and implementation of a computational method able to produce free energies in multiple dimensions,descriptively named the free energies from adaptive reaction coordinate forces(FEARCF) method is descri...The development and implementation of a computational method able to produce free energies in multiple dimensions,descriptively named the free energies from adaptive reaction coordinate forces(FEARCF) method is described in this paper.While the method can be used to calculate free energies of association,conformation and reactivity here it is shown in the context of chemical reaction landscapes.A reaction free energy surface for the Claisen rearrangement of chorismate to prephenate is used as an illustration of the method's efficient convergence.FEARCF simulations are shown to achieve flat histograms for complex multidimensional free energy volumes.The sampling efficiency by which it produces multidimensional free energies is demonstrated on the complex puckering of a pyranose ring,that is described by a three dimensional W(θ1,θ2,θ3) potential of mean force.展开更多
In order to understand the influence of supergravity on the microstructure of materials,crystal nucleation,dendritic growth,and polycrystal solidification under supergravity are investigated by using the modified nucl...In order to understand the influence of supergravity on the microstructure of materials,crystal nucleation,dendritic growth,and polycrystal solidification under supergravity are investigated by using the modified nucleation theory and phase field models.Firstly,supergravity is considered in the nucleation theory by using pressure-dependent Gibbs free energy.It is found that the critical radius decreases and the nucleation rate increases when supergravity rises.Secondly,anisotropic heat transport is proposed in the phase field model to investigate the influence of supergravity on dendritic growth.Phase field simulations show that supergravity promotes the secondary dendritic growth in the direction parallel to supergravity.Finally,a multiply phase field model with pressure-dependent interfacial energy is employed to simulate the polycrystalline solidification under supergravity.Due to the depth-dependent pressure by supergravity,crystal grains are significantly refined by high pressure.In addition,gradient distribution of grain size is obtained in the solidification morphology of polycrystalline,which is consistent with previous experimental observations.Results of this work suggest that supergravity can be used to tune the microstructures and properties of materials.展开更多
基金This work is supported by the National Key Basic Research Special Foundation (No.2010CB923300), the National Natural Science Foundation of China (No.20925311, No.91127042, and No.21103158), and the GSran Gustafsson Foundation for Research in Natural Sciences and Medicine.
文摘The molecular structure of liquid water has been an outstanding issue for many years. The identification of free -OH holds the key in differentiating structure models for liquid water. By analyzing the relative changes of the intensity and depolarization ratio in temperature dependent Raman spectra, the occurrence of free -OH in liquid water is unambiguously de- termined. Furthermore, upon the increase of temperature from 5 ~C to 85 ~C, the structure of liquid water undergoes significant change, but the relative proportion of free -OH is con- siderably small and remains almost unchanged. This implies that the breaking of hydrogen bond from the tetrahedral structure prefers to The energetic favoring of the structural change experiments. occur at the site of the hydrogen acceptor. for liquid water is thus clearly revealed from
基金sponsored by the Key Program of National Natural Science Foundation of China ( 40730317)
文摘We firstly detected the Earth's free toroidal oscillations excited by three large earthquakes in Japan,2011,Chile,2010 and Indonesia,2005 from the observed data of the JCZ-1 seismometer at Wuhan Seismic Station. The eigenperiods of basic modes (0T2 - 0T67 ) and first modes (1T2 ~ 1T50 ) were detected,and their error ratios were less than 0. 5% by comparing the observed eigenvalues with the theoretical eigenvalues in PREM. We supplemented some modes- 0T11,0T15 , 0T19 , 1T4 , 1T5 and 1T14 ,which were not mentioned in PREM,and also observed the spectral line multi-peak phenomenon from 0T2, 0T6 , 0T7 and 0T8 . These results show that the JCZ-1 seismometer is able to precisely observe the Earth's long period toroidal free oscillations.
文摘This research uses a theoretical conceptual method based on Chantal Mouffe's Radical Democracy which blended with Derrida's deconstruction thesis about "democracy to come" to reach findings on the state of South Africa's media freedom landscape. The method is contained in the conceptual framework. The article provides the constitutional legal landscape--or the overarching laws of the land--and the co-regulatory framework within which journalists work. There are four research explications: the Protection of State Information Bill (dubbed the Secrecy Bill), a painting of the president and Freedom of Expression, an arson attack on a community radio station and finally, the death of a photojournalist at the hands of police. The argument here is that the death, the arson attack, the Secrecy Bill, and the shut-down of dissent during the exhibition of the painting of the president all undermine democracy and signify significant closures for the media in the now 20-year-old post-apartheid South Africa. The analysis and reflections will be framed within theories of radical democracy, which argue for more fights and contestations and more voices from the margins in order to deepen democracy, rather than rational consensus which closes the spaces for greater plurality.
基金funded by the“Three-in-One”subject of China Earthquake Administration(201324)the Science and Technology Projects of Earthquake Administration of Zhejiang Province(2015ZJJ03)
文摘By using the digital observations of the pendulum tiltmeter, water tube tiltmeter,extensometer and volumetric strainmeter at Huzhou station and with the power spectrum density estimation method,we acquired the_0S_5-_0S_50 fundamental sphere free oscillations caused by the Japan earthquake on March 11,2011,then compared it with the PREM model. The relative errors are mostly bigger than 1.2‰. The extensometer and volume strainmeter can clearly detect _0S_2,_0S_3and_0S_4,which are closely related to the deep structure and earth's interior.
基金supported in part by the Major State Basic Research Developing Program (Grant No 2007CB815000)the National Natural Science Foundation of China (Grant Nos 11005004, 10775004 and 10975008)+1 种基金the Southwest University Initial Research Foundation Grant to Doctor (Grant No.SWU110039)MZOS (Grant No 1191005-1010)
文摘The rapid transition between spherical and γ-soft shapes in Zn isotopes in the mass A 70 region,is analyzed using excitation spectra and collective wave functions obtained by diagonalization of a five-dimensional Hamiltonian for quadrupole vibrational and rotational degrees of freedom,with parameters determined by constrained self-consistent relativistic mean-field calculations for triaxial shapes.The microscopic potential energy surfaces,together with the characteristic collective observables,illustrate a rapid transition from near spherical shape at the N = 40 subshell,to γ-soft deformed shapes for lighter isotopes.The calculated spectra display fingerprints of a second-order shape phase transition that can be approximately described by the E(5) analytic solution.
基金supported by the South African Research Chairs Initiative of the Department of Science and Technologythe National Research Foundation awarded to Kevin J. Naidoo
文摘The development and implementation of a computational method able to produce free energies in multiple dimensions,descriptively named the free energies from adaptive reaction coordinate forces(FEARCF) method is described in this paper.While the method can be used to calculate free energies of association,conformation and reactivity here it is shown in the context of chemical reaction landscapes.A reaction free energy surface for the Claisen rearrangement of chorismate to prephenate is used as an illustration of the method's efficient convergence.FEARCF simulations are shown to achieve flat histograms for complex multidimensional free energy volumes.The sampling efficiency by which it produces multidimensional free energies is demonstrated on the complex puckering of a pyranose ring,that is described by a three dimensional W(θ1,θ2,θ3) potential of mean force.
基金This work was supported by the Basic Science Center Program for Multiphase Evolution in Hypergravity of the National Natural Science Foundation of China(Grant No.51988101)the National Natural Science Foundation of China(Grant Nos.12192214 and 11972320)the Key Research Project of Zhejiang Laboratory(Grant No.2021PE0AC02).
文摘In order to understand the influence of supergravity on the microstructure of materials,crystal nucleation,dendritic growth,and polycrystal solidification under supergravity are investigated by using the modified nucleation theory and phase field models.Firstly,supergravity is considered in the nucleation theory by using pressure-dependent Gibbs free energy.It is found that the critical radius decreases and the nucleation rate increases when supergravity rises.Secondly,anisotropic heat transport is proposed in the phase field model to investigate the influence of supergravity on dendritic growth.Phase field simulations show that supergravity promotes the secondary dendritic growth in the direction parallel to supergravity.Finally,a multiply phase field model with pressure-dependent interfacial energy is employed to simulate the polycrystalline solidification under supergravity.Due to the depth-dependent pressure by supergravity,crystal grains are significantly refined by high pressure.In addition,gradient distribution of grain size is obtained in the solidification morphology of polycrystalline,which is consistent with previous experimental observations.Results of this work suggest that supergravity can be used to tune the microstructures and properties of materials.