Here, using the Scale-Symmetric Theory (SST) we explain the cosmological tension and the origin of the largest cosmic structures. We show that a change in value of strong coupling constant for cold baryonic matter lea...Here, using the Scale-Symmetric Theory (SST) we explain the cosmological tension and the origin of the largest cosmic structures. We show that a change in value of strong coupling constant for cold baryonic matter leads to the disagreement in the galaxy clustering amplitude, quantified by the parameter S8. Within the same model we described the Hubble tension. We described also the mechanism that transforms the gravitational collapse into an explosion—it concerns the dynamics of virtual fields that lead to dark energy. Our calculations concern the Type Ia supernovae and the core-collapse supernovae. We calculated the quantized masses of the progenitors of supernovae, emitted total energy during explosion, and we calculated how much of the released energy was transferred to neutrinos. Value of the speed of sound in the strongly interacting matter measured at the LHC confirms that presented here model is correct. Our calculations show that the Universe is cyclic.展开更多
The electron capture timescale may be shorter than hydrodynamic timescale in inner iron core of core-collapse supernova according to a recent new idea. Based on the new idea, this paper carries out a numerical simulat...The electron capture timescale may be shorter than hydrodynamic timescale in inner iron core of core-collapse supernova according to a recent new idea. Based on the new idea, this paper carries out a numerical simulation on supernova explosion for the progenitor model Ws15M. The numerical result shows that the size of proto-neutron star has a significant change （decrease about 20%）, which may affects the propagation of the shock wave and the final explosion energy.展开更多
We report the superconductivity in iron-based oxyarsenide Sm[O1-xFx]FeAs, with the onset resistivity transition temperature at 55.0K and Meissner transition at 54.6K. This compound has the same crystal structure as La...We report the superconductivity in iron-based oxyarsenide Sm[O1-xFx]FeAs, with the onset resistivity transition temperature at 55.0K and Meissner transition at 54.6K. This compound has the same crystal structure as LaOFeAs with shrunk crystal lattices, and becomes the superconductor with the highest critical temperature among all materials besides copper oxides up to now.展开更多
Polymer flooding is an efficient technique to enhance oil recovery over water flooding. There are lots of discussions regarding the mechanisms for polymer flooding enhancing oil recovery. The main focus is whether pol...Polymer flooding is an efficient technique to enhance oil recovery over water flooding. There are lots of discussions regarding the mechanisms for polymer flooding enhancing oil recovery. The main focus is whether polymer flooding can increase sweep efficiency alone, or can increase both of sweep efficiency and displacement efficiency. We present a study on this problem. Oil displacement experiments on 4 natural cores show that polymer flooding can increase oil recovery efficiency by more than 12% over water. Moreover, photos are taken by the nuclear magnetic resonance （NMR） method both after water flooding and after polymer flooding, which show remaining oil saturation distribution at the middle cross section and the central longitudinal section. Analyses of these photos demonstrate that polymer flooding can increase both sweep efficiency and displacement efficiency.展开更多
A new technique, the extended homoclinic test technique, is proposed to seek periodic solitary wave solutions of integrable systems. Exact periodic solitary-wave solutions for classical KdV equation are obtained using...A new technique, the extended homoclinic test technique, is proposed to seek periodic solitary wave solutions of integrable systems. Exact periodic solitary-wave solutions for classical KdV equation are obtained using this technique. This result shows that it is entirely possible for the （l ＋ l）-dimensional integrable equation that there exists a periodic solitary-wave.展开更多
Conformed invariance and conserved quantities of general holonomic systems are studied. A one-parameter infinitesimal transformation group and its infinitesimal transformation vector of generators are described. The d...Conformed invariance and conserved quantities of general holonomic systems are studied. A one-parameter infinitesimal transformation group and its infinitesimal transformation vector of generators are described. The definition of conformal invariance and determining equation for the system are provided. The conformal factor expression is deduced from conformal invariance and Lie symmetry. The necessary and suttlcient condition, that conformal invariance of the system would be Lie symmetry, is obtained under the infinitesimal one-parameter transformation group. The corresponding conserved quantity is derived with the aid of a structure equation. Lastly, an example is given to demonstrate the application of the result.展开更多
Thermoelectric （TE） performances are systematically investigated for the pellets of poly（3,4-ethylenedioxythiophene）：poly（styrenesulfonate） （PEDOT：PSS） with different organic additives and heating process as...Thermoelectric （TE） performances are systematically investigated for the pellets of poly（3,4-ethylenedioxythiophene）：poly（styrenesulfonate） （PEDOT：PSS） with different organic additives and heating process as organic TE materials. The electrical conductivity, Seebeck coefficient and thermal conductivity versus temperature are determined, respectively. It is found that there is no distinct change for the Seebeck coefficient among each sample with the additions of dimethyl sulfoxide and ethylene glycol. The thermal conductivity measured in a wide range of temperature indicates that the PEDOT：PSS pellet have an extremely low value. The highest figure of merit （ZT = 1.75×10^-3） is observed at 270K among the PEDOT：PSS pellets.展开更多
We propose a scheme of quantum secret sharing between Alice＇s group and Bob＇s group with single photons and unitary transformations. In the protocol, one member in Alice＇s group prepares a sequence of single photon...We propose a scheme of quantum secret sharing between Alice＇s group and Bob＇s group with single photons and unitary transformations. In the protocol, one member in Alice＇s group prepares a sequence of single photons in one of four different states, while other members directly encode their information on the sequence of single photons via unitary operations; after that, the last member sends the sequence of single photons to Bob＇s group. Then Bob＇s, except for the last one, do work similarly. Finally the last member in Bob＇s group measures the qubits. If the security of the quantum channel is guaranteed by some tests, then the qubit states sent by the last member of Alice＇s group can be used as key bits for secret sharing. It is shown that this scheme is safe.展开更多
Analytical prediction of heteroclinic bifurcation of the strongly nonlinear oscillator is presented by using the extended normal form method. We consider the approximate periodic solution of the system subject to the ...Analytical prediction of heteroclinic bifurcation of the strongly nonlinear oscillator is presented by using the extended normal form method. We consider the approximate periodic solution of the system subject to the quintic nonlinearity by introducing the undetermined fundamental frequency. For the occurrence of heteroclinicity, the bifurcation criterion is accomplished. It depends on the contact of the limit cycle with the saddle equilibrium. As is illustrated, the explicit application shows that the new results coincide very well with the results of numerical simulation when disturbing parameter is of arbitrary magnitude.展开更多
For a special coupled mKdV system, which can be derived from a two-layer fluid model, Hirota＇s bilinear direct method is used to construct and yield the complexiton solutions. The detailed physical properties of comp...For a special coupled mKdV system, which can be derived from a two-layer fluid model, Hirota＇s bilinear direct method is used to construct and yield the complexiton solutions. The detailed physical properties of complexitons are filrther illustrated graphically.展开更多
We report a thulium-doped silica fibre laser that generates a maximum cw output power of 6 W in a 2 μm wavelength range when cladding-pumped by a laser diode （LD） operating at approximately 791 nm at room temperatu...We report a thulium-doped silica fibre laser that generates a maximum cw output power of 6 W in a 2 μm wavelength range when cladding-pumped by a laser diode （LD） operating at approximately 791 nm at room temperature. The slope efficiency with respect to the launched pump power is 50% and 38.4%, with and without an output coupler mirror, respectively. The corresponding thresholds are 2.8 W and 4.8 W, respectively. The beam qualities Mx^2 and My^2 are 1.26 and 1.32, respectively. The experimental results are also analysed.展开更多
The Ising or Potts models of ferromagnetism have been widely used to describe locally interacting social or economic systems. We consider a related model, introduced by Sznajd to describe the evolution of consensus in...The Ising or Potts models of ferromagnetism have been widely used to describe locally interacting social or economic systems. We consider a related model, introduced by Sznajd to describe the evolution of consensus in the scale-free networks with the tunable strength （noted by Q） of community structure. In the Sznajd model, the opinion or state of any spins can only be changed by the influence of neighbouring pairs of similar connection spins. Such pairs can polarize their neighbours. Using asynchronous updating, it is found that the smaller the community strength Q, the larger the slope of the exponential relaxation time distribution. Then the effect of the initial upspin concentration p as a function of the final all up probability E is investigated by taking different initialization strategies, the random node-chosen initialization strategy has no difference under different community strengths, while the strategies of community node-chosen initialization and hub node-chosen initialization are different in fina/probability under different Q, and the latter one is more effective in reaching final state.展开更多
Critical impact velocity （CIV） of oxygen-free high-conductivity （OFHC） copper is experimentally measured with a novel facility in a gas gun system. The results are compared with the theoretical predictions using t...Critical impact velocity （CIV） of oxygen-free high-conductivity （OFHC） copper is experimentally measured with a novel facility in a gas gun system. The results are compared with the theoretical predictions using the typical constitutive relations, and the measured CIV value is much lower than the predictions. The difference of physical mechanisms in experiment and in theoretical calculation is discussed. It is suggested that the reduction of CIV in experiment would be related with the damage evolution in tensile copper that needs to be considered in the computation model.展开更多
Pig ions are confined in a hyperboloid ion trap. With the rf discharge ^202 Hg isotope lamp, the fluorescence signal of trapped Hg ions is observed. By means of buffer gas cooling, the ionic temperature is reduced. As...Pig ions are confined in a hyperboloid ion trap. With the rf discharge ^202 Hg isotope lamp, the fluorescence signal of trapped Hg ions is observed. By means of buffer gas cooling, the ionic temperature is reduced. As a result, the trapping time is increased and the signal-to-noise ratio （SNR） of the fluorescent signal is improved. The temperature of ion cloud is estimated by measuring the space charge shift.展开更多
Different element substitution effects in transition metal oxypnictide Re（O1-xFx）TAs, with Re=La, Ce, Nd, Eu, Od, Tm, T=Fe, Ni, Ru, are studied. Similar to the La- or Ce-based systems, we find that the pure NdOFeAs ...Different element substitution effects in transition metal oxypnictide Re（O1-xFx）TAs, with Re=La, Ce, Nd, Eu, Od, Tm, T=Fe, Ni, Ru, are studied. Similar to the La- or Ce-based systems, we find that the pure NdOFeAs shows a strong resistivity anomaly near 145K, which is ascribed to the spin-density-wave instability. Electron doping by F increases Tc to about 50K. While in the case of Gd, Tc is reduced below 10K. The tetragonal ZrCuSiAs-type structure could not be formed for Eu or Tm substitution in our preparing process. For the Ni-based case, although both pure and F-doped LaONiAs are superconducting, no superconductivity is found when La is replaced by Ce in both the cases, instead a ferromagnetic ordering transition is likely to form at low temperature in the undoped sample. We also synthesize LaO1-xFxRuAs and CeO1-xFxRuAs compounds. The metallic behaviour is observed down to 4 K.展开更多
Molecular dissociation energies of 10 electronic states of alkali molecules of KH, ^7LiD, ^7 LiH, ^6LiH, NaK, NaLi and NaRb are studied using the highest three accurate vibrational energies of each electronic state, a...Molecular dissociation energies of 10 electronic states of alkali molecules of KH, ^7LiD, ^7 LiH, ^6LiH, NaK, NaLi and NaRb are studied using the highest three accurate vibrational energies of each electronic state, and an improved parameter-free analytical formula which is obtained starting from the LeRoy Bernstein vibrational energy expression near the dissociation limit. The results show that as long as the highest three vibrational energies are accurate, the current analytical formula will give accurate theoretical dissociation energies De^theory, which are in excellent agreement with the experimental dissociation energies De^expt.展开更多
N-ZnO/p-Si heterojunctions are prepared by sputtering deposition of intrinsic ZnO films on p-Si substrates. Thicknesses of ZnO films are altered by varying the deposition time from I h to 3h. The electrical properties...N-ZnO/p-Si heterojunctions are prepared by sputtering deposition of intrinsic ZnO films on p-Si substrates. Thicknesses of ZnO films are altered by varying the deposition time from I h to 3h. The electrical properties of these structures are analysed from capacitance-voltage （C V） and current-voltage （I-V） characteristics performed in a dark room. The results demonstrated that all the samples show strong rectifying behaviour. Photovoltaie property for the samples with different thicknesses of ZnO films are investigated by measuring open circuit voltage and short circuit current. It is found that photovoltages are kept to be almost constant of 320 m V along with the thickness while photoeurrents changing a lot. The variation mechanism of the photovoltade effect as a function of thickness of ZnO films is investigated.展开更多
We report on InP-based metamorphic InGaAs photodiodes grown by gas source molecular beam epitaxy （MBE）, in which a relatively thin compositional graded wide band-gap InxAl1-xAs buffer layer is adopted. In the photod...We report on InP-based metamorphic InGaAs photodiodes grown by gas source molecular beam epitaxy （MBE）, in which a relatively thin compositional graded wide band-gap InxAl1-xAs buffer layer is adopted. In the photodiodes, InAiAs is also taken as cap layers, so this structure is suitable for both front and back illuminations. At room temperature the photodiodes show 50% cut-off wavelength of 2.66μm, with measured peak detectivity of 4.91×10^9 cmHz^1/2/W at 2.57μm, and the typical dark current and RoA are 7.68μA/0.94Ωcm^2 and 291 nA/24.29Ωcm^2 at 290 K and 150 K respectively for the devices in diameter 300 μm. Their performances are compared to the 2.5μm cut-off photodiodes with similar structures.展开更多
We report the specific heat measurements on the newly discovered Fe-based layered LaO0.9Fo0.1-δFeAs superconductor with the onset transition temperature Tc ≈ 28 K. A nonlinear magnetic field dependence of the electr...We report the specific heat measurements on the newly discovered Fe-based layered LaO0.9Fo0.1-δFeAs superconductor with the onset transition temperature Tc ≈ 28 K. A nonlinear magnetic field dependence of the electronic specific heat coefficient γ（ H） has been found in the low temperature limit, which is consistent with the prediction for a nodal superconductor. The maximum gap value △0 ≈ 3.4 ± 0.5 meV is derived by analysing γ（H） based on the d-wave model. We also detected the electronic specific heat difference between 9 T and 0 T in a wide temperature range, a specific heat anomaly can be clearly observed near Tc, The Debye temperature of our sample is determined to be about 315.7K. Our results suggest an unconventional mechanism for this new superconductor.展开更多
We study the relationship between the properties of the isovector giant dipole resonance of finite nuclei and the symmetry energy in the framework of the relativistic mean field theory with six different parameter set...We study the relationship between the properties of the isovector giant dipole resonance of finite nuclei and the symmetry energy in the framework of the relativistic mean field theory with six different parameter sets of nonlinear effective Lagrangian. A strong linear correlation of excited energies of the dipole resonance in finite nuclei and symmetry energy at and below the saturation density is found. This linear correlation leads to the symmetry energy at the saturation density at the interval 33.0 MeV ≤ S（po） 〈37.0 MeV. The comparison to the present experimental data in the soft dipole mode of 132Sn constrains approximately the symmetry energy at p = 0,1 fm^-3 at the interval 21,2MeV- 22.5 MeV. It is proposed that a precise measurement of the soft dipole mode in neutron rich nuclei could set up an important constraint on the equation of state for asymmetric nuclear matter.展开更多
文摘Here, using the Scale-Symmetric Theory (SST) we explain the cosmological tension and the origin of the largest cosmic structures. We show that a change in value of strong coupling constant for cold baryonic matter leads to the disagreement in the galaxy clustering amplitude, quantified by the parameter S8. Within the same model we described the Hubble tension. We described also the mechanism that transforms the gravitational collapse into an explosion—it concerns the dynamics of virtual fields that lead to dark energy. Our calculations concern the Type Ia supernovae and the core-collapse supernovae. We calculated the quantized masses of the progenitors of supernovae, emitted total energy during explosion, and we calculated how much of the released energy was transferred to neutrinos. Value of the speed of sound in the strongly interacting matter measured at the LHC confirms that presented here model is correct. Our calculations show that the Universe is cyclic.
基金Project supported by the National Natural Science Foundation of China(Grant No10778719)the Scientific Research and Fund of Sichuan Provincial Education Department of China(Grant No2006A079)the Science and Technological Foundation of China West Normal University
文摘The electron capture timescale may be shorter than hydrodynamic timescale in inner iron core of core-collapse supernova according to a recent new idea. Based on the new idea, this paper carries out a numerical simulation on supernova explosion for the progenitor model Ws15M. The numerical result shows that the size of proto-neutron star has a significant change （decrease about 20%）, which may affects the propagation of the shock wave and the final explosion energy.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10734120 and 50571111, and National Basic Research Program of China under Grant Nos 2006CB601001 and 2007CB925002, and the Project COMEPHS TTC from EC.
文摘We report the superconductivity in iron-based oxyarsenide Sm[O1-xFx]FeAs, with the onset resistivity transition temperature at 55.0K and Meissner transition at 54.6K. This compound has the same crystal structure as LaOFeAs with shrunk crystal lattices, and becomes the superconductor with the highest critical temperature among all materials besides copper oxides up to now.
基金Supported by the National Natural Science Foundation of China under Grant No 50634020.
文摘Polymer flooding is an efficient technique to enhance oil recovery over water flooding. There are lots of discussions regarding the mechanisms for polymer flooding enhancing oil recovery. The main focus is whether polymer flooding can increase sweep efficiency alone, or can increase both of sweep efficiency and displacement efficiency. We present a study on this problem. Oil displacement experiments on 4 natural cores show that polymer flooding can increase oil recovery efficiency by more than 12% over water. Moreover, photos are taken by the nuclear magnetic resonance （NMR） method both after water flooding and after polymer flooding, which show remaining oil saturation distribution at the middle cross section and the central longitudinal section. Analyses of these photos demonstrate that polymer flooding can increase both sweep efficiency and displacement efficiency.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10361007 and 10661002, and the Natural Science Foundation of Yunnan Province under Grant No 2006A0082M.
文摘A new technique, the extended homoclinic test technique, is proposed to seek periodic solitary wave solutions of integrable systems. Exact periodic solitary-wave solutions for classical KdV equation are obtained using this technique. This result shows that it is entirely possible for the （l ＋ l）-dimensional integrable equation that there exists a periodic solitary-wave.
文摘Conformed invariance and conserved quantities of general holonomic systems are studied. A one-parameter infinitesimal transformation group and its infinitesimal transformation vector of generators are described. The definition of conformal invariance and determining equation for the system are provided. The conformal factor expression is deduced from conformal invariance and Lie symmetry. The necessary and suttlcient condition, that conformal invariance of the system would be Lie symmetry, is obtained under the infinitesimal one-parameter transformation group. The corresponding conserved quantity is derived with the aid of a structure equation. Lastly, an example is given to demonstrate the application of the result.
基金Supported by the National Natural Science Foundation of China under Grant No 50663001, the Ministry of Education of China （2007-207058）, the Natural Science Foundation of Jiangxi Province （2007GZH1091）, and Fund of Jiangxi Provincial Department of Education （GJJ08369）.
文摘Thermoelectric （TE） performances are systematically investigated for the pellets of poly（3,4-ethylenedioxythiophene）：poly（styrenesulfonate） （PEDOT：PSS） with different organic additives and heating process as organic TE materials. The electrical conductivity, Seebeck coefficient and thermal conductivity versus temperature are determined, respectively. It is found that there is no distinct change for the Seebeck coefficient among each sample with the additions of dimethyl sulfoxide and ethylene glycol. The thermal conductivity measured in a wide range of temperature indicates that the PEDOT：PSS pellet have an extremely low value. The highest figure of merit （ZT = 1.75×10^-3） is observed at 270K among the PEDOT：PSS pellets.
基金Supported by the National Natural Science Foundation of China under Grant No 10671054, the Natural Science Foundation of Hebei Province under Grant Nos A2005000140 and 07M006, and the Key Project of Science and Technology Research of Ministry of Education of China under Grant No 207011.
文摘We propose a scheme of quantum secret sharing between Alice＇s group and Bob＇s group with single photons and unitary transformations. In the protocol, one member in Alice＇s group prepares a sequence of single photons in one of four different states, while other members directly encode their information on the sequence of single photons via unitary operations; after that, the last member sends the sequence of single photons to Bob＇s group. Then Bob＇s, except for the last one, do work similarly. Finally the last member in Bob＇s group measures the qubits. If the security of the quantum channel is guaranteed by some tests, then the qubit states sent by the last member of Alice＇s group can be used as key bits for secret sharing. It is shown that this scheme is safe.
基金Supported by the Specialized Research Fund for the Doctoral Programme of Higher Education of China and the National Natural Science Foundation of China under Grant Nos 20060056005 and 10372068.
文摘Analytical prediction of heteroclinic bifurcation of the strongly nonlinear oscillator is presented by using the extended normal form method. We consider the approximate periodic solution of the system subject to the quintic nonlinearity by introducing the undetermined fundamental frequency. For the occurrence of heteroclinicity, the bifurcation criterion is accomplished. It depends on the contact of the limit cycle with the saddle equilibrium. As is illustrated, the explicit application shows that the new results coincide very well with the results of numerical simulation when disturbing parameter is of arbitrary magnitude.
文摘For a special coupled mKdV system, which can be derived from a two-layer fluid model, Hirota＇s bilinear direct method is used to construct and yield the complexiton solutions. The detailed physical properties of complexitons are filrther illustrated graphically.
基金Supported by the National Natural Science Foundation of China under No 60471048, and the Shenzhen Science and Technology Bureau under Grant No 200617.
文摘We report a thulium-doped silica fibre laser that generates a maximum cw output power of 6 W in a 2 μm wavelength range when cladding-pumped by a laser diode （LD） operating at approximately 791 nm at room temperature. The slope efficiency with respect to the launched pump power is 50% and 38.4%, with and without an output coupler mirror, respectively. The corresponding thresholds are 2.8 W and 4.8 W, respectively. The beam qualities Mx^2 and My^2 are 1.26 and 1.32, respectively. The experimental results are also analysed.
基金Supported by the National Natural Science Foundations of China under Grant Nos 70571027, 70401020,10647125 and 10635020, and the Ministry of Education of China under Grant No 306022.
文摘The Ising or Potts models of ferromagnetism have been widely used to describe locally interacting social or economic systems. We consider a related model, introduced by Sznajd to describe the evolution of consensus in the scale-free networks with the tunable strength （noted by Q） of community structure. In the Sznajd model, the opinion or state of any spins can only be changed by the influence of neighbouring pairs of similar connection spins. Such pairs can polarize their neighbours. Using asynchronous updating, it is found that the smaller the community strength Q, the larger the slope of the exponential relaxation time distribution. Then the effect of the initial upspin concentration p as a function of the final all up probability E is investigated by taking different initialization strategies, the random node-chosen initialization strategy has no difference under different community strengths, while the strategies of community node-chosen initialization and hub node-chosen initialization are different in fina/probability under different Q, and the latter one is more effective in reaching final state.
基金Supported by the National Natural Science Foundation of China under Grant No 10672082, the Scientific Research Fund of Zhejiang Provincial Education Department under Grant No 20061673, and K. C. Wong Magna Fund in Ningbo University.
文摘Critical impact velocity （CIV） of oxygen-free high-conductivity （OFHC） copper is experimentally measured with a novel facility in a gas gun system. The results are compared with the theoretical predictions using the typical constitutive relations, and the measured CIV value is much lower than the predictions. The difference of physical mechanisms in experiment and in theoretical calculation is discussed. It is suggested that the reduction of CIV in experiment would be related with the damage evolution in tensile copper that needs to be considered in the computation model.
文摘Pig ions are confined in a hyperboloid ion trap. With the rf discharge ^202 Hg isotope lamp, the fluorescence signal of trapped Hg ions is observed. By means of buffer gas cooling, the ionic temperature is reduced. As a result, the trapping time is increased and the signal-to-noise ratio （SNR） of the fluorescent signal is improved. The temperature of ion cloud is estimated by measuring the space charge shift.
基金Supported by the National Natural Science Foundation of China, the Knowledge Innovation Project of the Chinese Academy of Sciences, and the National Basic Research Programme of China under Grant No 2006CB9213001.
文摘Different element substitution effects in transition metal oxypnictide Re（O1-xFx）TAs, with Re=La, Ce, Nd, Eu, Od, Tm, T=Fe, Ni, Ru, are studied. Similar to the La- or Ce-based systems, we find that the pure NdOFeAs shows a strong resistivity anomaly near 145K, which is ascribed to the spin-density-wave instability. Electron doping by F increases Tc to about 50K. While in the case of Gd, Tc is reduced below 10K. The tetragonal ZrCuSiAs-type structure could not be formed for Eu or Tm substitution in our preparing process. For the Ni-based case, although both pure and F-doped LaONiAs are superconducting, no superconductivity is found when La is replaced by Ce in both the cases, instead a ferromagnetic ordering transition is likely to form at low temperature in the undoped sample. We also synthesize LaO1-xFxRuAs and CeO1-xFxRuAs compounds. The metallic behaviour is observed down to 4 K.
基金Supported by the National Natural Science Foundation of China under Grant No 10774105, and the Science Foundation of the Ministry of Education of China.
文摘Molecular dissociation energies of 10 electronic states of alkali molecules of KH, ^7LiD, ^7 LiH, ^6LiH, NaK, NaLi and NaRb are studied using the highest three accurate vibrational energies of each electronic state, and an improved parameter-free analytical formula which is obtained starting from the LeRoy Bernstein vibrational energy expression near the dissociation limit. The results show that as long as the highest three vibrational energies are accurate, the current analytical formula will give accurate theoretical dissociation energies De^theory, which are in excellent agreement with the experimental dissociation energies De^expt.
基金Supported by the National Natural Science Foundation of China under Grant No 50532070, and the Knowledge Innovation Project of Chinese Academy of Sciences under Grant No KJCX3.5YW.W01
文摘N-ZnO/p-Si heterojunctions are prepared by sputtering deposition of intrinsic ZnO films on p-Si substrates. Thicknesses of ZnO films are altered by varying the deposition time from I h to 3h. The electrical properties of these structures are analysed from capacitance-voltage （C V） and current-voltage （I-V） characteristics performed in a dark room. The results demonstrated that all the samples show strong rectifying behaviour. Photovoltaie property for the samples with different thicknesses of ZnO films are investigated by measuring open circuit voltage and short circuit current. It is found that photovoltages are kept to be almost constant of 320 m V along with the thickness while photoeurrents changing a lot. The variation mechanism of the photovoltade effect as a function of thickness of ZnO films is investigated.
文摘We report on InP-based metamorphic InGaAs photodiodes grown by gas source molecular beam epitaxy （MBE）, in which a relatively thin compositional graded wide band-gap InxAl1-xAs buffer layer is adopted. In the photodiodes, InAiAs is also taken as cap layers, so this structure is suitable for both front and back illuminations. At room temperature the photodiodes show 50% cut-off wavelength of 2.66μm, with measured peak detectivity of 4.91×10^9 cmHz^1/2/W at 2.57μm, and the typical dark current and RoA are 7.68μA/0.94Ωcm^2 and 291 nA/24.29Ωcm^2 at 290 K and 150 K respectively for the devices in diameter 300 μm. Their performances are compared to the 2.5μm cut-off photodiodes with similar structures.
基金Supported by the National Natural Science Foundation of China, the National Basic Research Programme of China under Grant Nos 2006CB601000 and 2006CB921802, and Chinese Academy of Sciences （ITSNEM）.
文摘We report the specific heat measurements on the newly discovered Fe-based layered LaO0.9Fo0.1-δFeAs superconductor with the onset transition temperature Tc ≈ 28 K. A nonlinear magnetic field dependence of the electronic specific heat coefficient γ（ H） has been found in the low temperature limit, which is consistent with the prediction for a nodal superconductor. The maximum gap value △0 ≈ 3.4 ± 0.5 meV is derived by analysing γ（H） based on the d-wave model. We also detected the electronic specific heat difference between 9 T and 0 T in a wide temperature range, a specific heat anomaly can be clearly observed near Tc, The Debye temperature of our sample is determined to be about 315.7K. Our results suggest an unconventional mechanism for this new superconductor.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10305014, 10475116 and 10535010, the National Basic Research Development Programme of China under Grant No 2007CB815000, and the Asia-Europe Link in Nuclear Physics and Astrophysics under Grant CN/ASIA-LINK/O08（94791）.
文摘We study the relationship between the properties of the isovector giant dipole resonance of finite nuclei and the symmetry energy in the framework of the relativistic mean field theory with six different parameter sets of nonlinear effective Lagrangian. A strong linear correlation of excited energies of the dipole resonance in finite nuclei and symmetry energy at and below the saturation density is found. This linear correlation leads to the symmetry energy at the saturation density at the interval 33.0 MeV ≤ S（po） 〈37.0 MeV. The comparison to the present experimental data in the soft dipole mode of 132Sn constrains approximately the symmetry energy at p = 0,1 fm^-3 at the interval 21,2MeV- 22.5 MeV. It is proposed that a precise measurement of the soft dipole mode in neutron rich nuclei could set up an important constraint on the equation of state for asymmetric nuclear matter.
