2007 Vol. 24, No. 1
Display Method:
2007, 24(1): 1-5.
doi: 10.11804/NuclPhysRev.24.01.001
Abstract:
Ever since the theory of color superconductivity was issued， it is likely to involve pairing between species of quarks with differing chemical potentials. For suitable values of the differences between chemical potentials， Cooper pairs with nonzero total momentum are favored， as was first realized by Larkin， Ovchinnikov， Fulde and Ferrell (LOFF). Condensates of this sort spontaneously break translational and rotational invariance， leading to gaps which vary periodically in a crystalline pattern. This article focuses on the twoflavor color superconducting phase at moderate baryon density. LOFF state is described through SU(2) NJL model. By using the meanfield approximation， NG basis， fourier transformation， frequency summation， the thermodynamic potential and Gap equation are obtained. Finally， the window of LOFF state is found by the numerical method.
Ever since the theory of color superconductivity was issued， it is likely to involve pairing between species of quarks with differing chemical potentials. For suitable values of the differences between chemical potentials， Cooper pairs with nonzero total momentum are favored， as was first realized by Larkin， Ovchinnikov， Fulde and Ferrell (LOFF). Condensates of this sort spontaneously break translational and rotational invariance， leading to gaps which vary periodically in a crystalline pattern. This article focuses on the twoflavor color superconducting phase at moderate baryon density. LOFF state is described through SU(2) NJL model. By using the meanfield approximation， NG basis， fourier transformation， frequency summation， the thermodynamic potential and Gap equation are obtained. Finally， the window of LOFF state is found by the numerical method.
2007, 24(1): 6-9.
doi: 10.11804/NuclPhysRev.24.01.006
Abstract:
The Skyrme model and its descriptions for baryons have been introduced briefly. Then， we give three dibaryon chiral soliton solutions which are different from Balachandran’s configuration. By Witten’s way， we quantize these solitons and obtain dibaryon mass spectrum. These solitons have different spatial symmetry， but the same mass spectrum.
The Skyrme model and its descriptions for baryons have been introduced briefly. Then， we give three dibaryon chiral soliton solutions which are different from Balachandran’s configuration. By Witten’s way， we quantize these solitons and obtain dibaryon mass spectrum. These solitons have different spatial symmetry， but the same mass spectrum.
2007, 24(1): 10-15.
doi: 10.11804/NuclPhysRev.24.01.010
Abstract:
QCD sum rule is an important nonperturbative method in hadron physics， it has been a powerful technique in study of hadron physics and nuclear physics.We give a brief introduction to the basic idea， the method and its application of QCD sum rule， emphasize the development of this method and some topics in recent years.
QCD sum rule is an important nonperturbative method in hadron physics， it has been a powerful technique in study of hadron physics and nuclear physics.We give a brief introduction to the basic idea， the method and its application of QCD sum rule， emphasize the development of this method and some topics in recent years.
2007, 24(1): 16-20.
doi: 10.11804/NuclPhysRev.24.01.016
Abstract:
We made a revision of square of virtual photon four momentum by means of using nuclear bin ding energy formula in different energy， and we also made an accurate calculation for the effect of nuclear binding energy on K factor and Compton term and annihilate term in the DrellYan process of the SnSn collision. The outcome indicates that the effect of nuclear binding energy on the annihilate term and the Compton term is marked in little x region and the effect will become more obvious with decrease of the energy and come to disappear with increase of the x.
We made a revision of square of virtual photon four momentum by means of using nuclear bin ding energy formula in different energy， and we also made an accurate calculation for the effect of nuclear binding energy on K factor and Compton term and annihilate term in the DrellYan process of the SnSn collision. The outcome indicates that the effect of nuclear binding energy on the annihilate term and the Compton term is marked in little x region and the effect will become more obvious with decrease of the energy and come to disappear with increase of the x.
2007, 24(1): 21-28.
doi: 10.11804/NuclPhysRev.24.01.021
Abstract:
The main mechanism of radioactive nucleus reaction at intermediate and high energy as well as the corresponding experiment equipment are introduced. The structure information of the radioactive nucleus can be extracted from the experiments. At last， the possible experiments are proposed for the external target experiment at CSR of Lanzhou.
The main mechanism of radioactive nucleus reaction at intermediate and high energy as well as the corresponding experiment equipment are introduced. The structure information of the radioactive nucleus can be extracted from the experiments. At last， the possible experiments are proposed for the external target experiment at CSR of Lanzhou.
2007, 24(1): 29-33.
doi: 10.11804/NuclPhysRev.24.01.029
Abstract:
We have measured the neutron radiative capture cross section of 75As in the energy range of En=29—1 100 keV using the activation technique at 2.5 MV electrostatic accelerator of Sichuan University. The experimental data were then corrected for multiple scattering and selfshielding effects with MCNP 4C code. We also compared our results， with the existing measurement， calculation and evaluated data in ENDF/BⅥ.
We have measured the neutron radiative capture cross section of 75As in the energy range of En=29—1 100 keV using the activation technique at 2.5 MV electrostatic accelerator of Sichuan University. The experimental data were then corrected for multiple scattering and selfshielding effects with MCNP 4C code. We also compared our results， with the existing measurement， calculation and evaluated data in ENDF/BⅥ.
2007, 24(1): 34-39.
doi: 10.11804/NuclPhysRev.24.01.034
Abstract:
It is shown that measuring the high energy hadrons in air shower cores at high altitudes (like Yangbajing) can provide some new observables which are sensitive to the cosmic ray composition at the knee region. Assuming a hadron calorimeter (like KASCADE calorimeter) is set up at the center of ARGO array， the event selection conditions are studied for that the primary energies of the selected events range just around the knee. The sample has a reasonable size for 1—2 years’ exposure and a number of observables are shown to be sensitive to the composition.
It is shown that measuring the high energy hadrons in air shower cores at high altitudes (like Yangbajing) can provide some new observables which are sensitive to the cosmic ray composition at the knee region. Assuming a hadron calorimeter (like KASCADE calorimeter) is set up at the center of ARGO array， the event selection conditions are studied for that the primary energies of the selected events range just around the knee. The sample has a reasonable size for 1—2 years’ exposure and a number of observables are shown to be sensitive to the composition.
2007, 24(1): 40-42.
doi: 10.11804/NuclPhysRev.24.01.040
Abstract:
核材料辐射出的γ射线对人体有很强的辐射损伤， 实际工作中多用铅玻璃对其进行屏蔽。 以甲状腺为研究对象， 应用蒙特卡罗方法通用软件MCNP4B程序建立模型， 模拟计算了操作人员在操作核弹头时， 弹头中产生的γ射线透过各种厚度的铅玻璃时人体甲状腺吸收剂量率。 结果表明， 铅玻璃确有良好的降低γ射线吸收剂量率的作用。
The γ ray which is radiated from a nuclear material can cause serious radiation damage to human organs， so lead glass are often used as a shielding material. In this paper， thyroid was the subject investigated. A mathematical model was established by using the general software code MCNP4B. We have calculated a series of thyroid’s absorbed dose rate when the γ ray which was generated from the warhead penetrated the various depths of the lead glass via the model. The results indicate that lead glass work well as a protector against γ rays.
2007, 24(1): 43-47.
doi: 10.11804/NuclPhysRev.24.01.043
Abstract:
In order to resolve the transport problem of neutron activated sample on Shenguang Ⅲ prototype， a rabbit system was designed. The structure and layout of the rabbit system on Shenguang Ⅲ prototype is introduced. By using pneumatic equation， the effects of gas pressure， viscous coefficient of lubricant and the distance between sample capsule and pipe wall on sample velocity were calculated and analyzed. The result shows that the rabbit system can transport the sample to designed position in 2.24 s， which basically satisfy the requirement of system design. This paper provides numerical reference for parameter choice of the rabbit system.
In order to resolve the transport problem of neutron activated sample on Shenguang Ⅲ prototype， a rabbit system was designed. The structure and layout of the rabbit system on Shenguang Ⅲ prototype is introduced. By using pneumatic equation， the effects of gas pressure， viscous coefficient of lubricant and the distance between sample capsule and pipe wall on sample velocity were calculated and analyzed. The result shows that the rabbit system can transport the sample to designed position in 2.24 s， which basically satisfy the requirement of system design. This paper provides numerical reference for parameter choice of the rabbit system.
2007, 24(1): 48-54.
doi: 10.11804/NuclPhysRev.24.01.048
Abstract:
ScholzKraft’s Local Effect Model (LEM) for the calculation of cell survival after heavyion irradiation was briefly introduced. Basing on the energy conservation law and the definition of the dose， the disfigurement of LEM in theoretical framework and methods was discussed. Two artificial parameters were found in LEM， and the result obtained from this model seriously depends on these two parameters.
ScholzKraft’s Local Effect Model (LEM) for the calculation of cell survival after heavyion irradiation was briefly introduced. Basing on the energy conservation law and the definition of the dose， the disfigurement of LEM in theoretical framework and methods was discussed. Two artificial parameters were found in LEM， and the result obtained from this model seriously depends on these two parameters.
2007, 24(1): 55-58.
doi: 10.11804/NuclPhysRev.24.01.055
Abstract:
The effect of 12C6+ beam irradiation on AdCMVGFP (a replication deficient recombinant adenoviral vector containing CMV promoter and green fluorescent protein) gene transfection efficiency for murine melanoma cell B16 has been investigated. B16 cells infected with AdCMVGFP were irradiated by different doses of 12C6+ beam. The transfection efficiency was assessed by flow cytometry (FCM). Results show that 12C6+ beam irradiation can improve tansfection efficiency of AdCMVGFP on murine melanoma cell B16 in a dosedependent manner. In addition， the tansfection efficiency in pretranfection plus irradiation group is higher than that in preirradiation plus tranfection group at the same dose irradiation dose.
The effect of 12C6+ beam irradiation on AdCMVGFP (a replication deficient recombinant adenoviral vector containing CMV promoter and green fluorescent protein) gene transfection efficiency for murine melanoma cell B16 has been investigated. B16 cells infected with AdCMVGFP were irradiated by different doses of 12C6+ beam. The transfection efficiency was assessed by flow cytometry (FCM). Results show that 12C6+ beam irradiation can improve tansfection efficiency of AdCMVGFP on murine melanoma cell B16 in a dosedependent manner. In addition， the tansfection efficiency in pretranfection plus irradiation group is higher than that in preirradiation plus tranfection group at the same dose irradiation dose.
2007, 24(1): 59-64.
doi: 10.11804/NuclPhysRev.24.01.059
Abstract:
The 7 research puzzles in the genetic improvement of biological bodies made by ion beam mediated technique, are worth noticed. The technical ideas, including one mediated technique in physics, 2 significant subjects, 3 effective changes, the mediated evidences of 4 aspects and 5 biological characteristics, were particularly put forward according to the existing states in the field. The 2 significant subjects consist of the mechanics of the allogenetic materials entering into the acceptor and they being to be recombined. The 3 effective changes include from studying morphology to genetic laws, from researching M1 generation to the next generations, from determining the single character to the synthetic traits. The mediated evidences of 4 aspects come from morphology, physiology and biochemistry, molecule biology. The 5 biological characteristics are mainly reproduction, development, photosynthesis, bad conditionresistant and quality.
The 7 research puzzles in the genetic improvement of biological bodies made by ion beam mediated technique, are worth noticed. The technical ideas, including one mediated technique in physics, 2 significant subjects, 3 effective changes, the mediated evidences of 4 aspects and 5 biological characteristics, were particularly put forward according to the existing states in the field. The 2 significant subjects consist of the mechanics of the allogenetic materials entering into the acceptor and they being to be recombined. The 3 effective changes include from studying morphology to genetic laws, from researching M1 generation to the next generations, from determining the single character to the synthetic traits. The mediated evidences of 4 aspects come from morphology, physiology and biochemistry, molecule biology. The 5 biological characteristics are mainly reproduction, development, photosynthesis, bad conditionresistant and quality.
2007, 24(1): 65-71.
doi: 10.11804/NuclPhysRev.24.01.065
Abstract:
The developing modern physical techniques offer a series of abundant and effective methods to study ATP synthase in structure and function. Firstly we stressed on the dialectic relationship between physical techniques and the improvement of science in history, and introduced a lot of physical techniques in common use in protein researches such as mass spectroscopy， nuclear magnetic resonance， synchronization Xray diffraction， infrared spectroscopy and ultraviolet spectroscopy, and then reviewed their application status in quo to ATP synthase. Secondly we paid our attention to the burgeoning unconventionally instruments, i.e., the atomic force microscope and the fluorescence resonance energy transform (FRET) which have attracted the professional attention， and introduced latest application and researches’ achievements. Compared the development of the techniques in recent years， we have set forth the shortcoming and excellence of all kinds of equipments introduced. And it was ended with the conclusion that it is necessary to manage the possible instruments effectively and sufficient for the personalities， and given out the optimum research routes which emphasized on the new techniques and novel methods, i.e., the atomic force microscope and FRET.
The developing modern physical techniques offer a series of abundant and effective methods to study ATP synthase in structure and function. Firstly we stressed on the dialectic relationship between physical techniques and the improvement of science in history, and introduced a lot of physical techniques in common use in protein researches such as mass spectroscopy， nuclear magnetic resonance， synchronization Xray diffraction， infrared spectroscopy and ultraviolet spectroscopy, and then reviewed their application status in quo to ATP synthase. Secondly we paid our attention to the burgeoning unconventionally instruments, i.e., the atomic force microscope and the fluorescence resonance energy transform (FRET) which have attracted the professional attention， and introduced latest application and researches’ achievements. Compared the development of the techniques in recent years， we have set forth the shortcoming and excellence of all kinds of equipments introduced. And it was ended with the conclusion that it is necessary to manage the possible instruments effectively and sufficient for the personalities， and given out the optimum research routes which emphasized on the new techniques and novel methods, i.e., the atomic force microscope and FRET.
2007, 24(1): 72-75.
doi: 10.11804/NuclPhysRev.24.01.072
Abstract:
To investigate the effects of cellcycle progression of A549 cell induced by 12C6+ ion irradiation at different doses, the survival fractions of the A549 cells were determined by colonyforming assay; cell cycles were analyzed by FACS at 12 h or 24 h after irradiation. The results showed that the percentage of survival in the A549 cells decreased with irradiation doses. Compared with control group， the percentage of the cells in G0/G1 phase significantly increased at 12 h after irradiation with different doses of 12C6+ ions. However， at 24 h after irradiation the percentage of the cells in G0/G1 phase significantly increased with 1.0 Gy 12C6+ ions， while the cells showed increasing percentage in G2/M phase with 2.0, 4.0 or 6.0 Gy 12C6+ ions. The results suggested that G1 cell cycle checkpoint was activated in 12—24 h after irradiation with 1.0 Gy 12C6+ ions， but after irradiation with 2.0—6.0 Gy 12C6+ ions， the cellcycle progression of the A549 cells changed with time.
To investigate the effects of cellcycle progression of A549 cell induced by 12C6+ ion irradiation at different doses, the survival fractions of the A549 cells were determined by colonyforming assay; cell cycles were analyzed by FACS at 12 h or 24 h after irradiation. The results showed that the percentage of survival in the A549 cells decreased with irradiation doses. Compared with control group， the percentage of the cells in G0/G1 phase significantly increased at 12 h after irradiation with different doses of 12C6+ ions. However， at 24 h after irradiation the percentage of the cells in G0/G1 phase significantly increased with 1.0 Gy 12C6+ ions， while the cells showed increasing percentage in G2/M phase with 2.0, 4.0 or 6.0 Gy 12C6+ ions. The results suggested that G1 cell cycle checkpoint was activated in 12—24 h after irradiation with 1.0 Gy 12C6+ ions， but after irradiation with 2.0—6.0 Gy 12C6+ ions， the cellcycle progression of the A549 cells changed with time.
2007, 24(1): 76-79.
doi: 10.11804/NuclPhysRev.24.01.076
Abstract:
The Monte Carlo (MC) and embeddedatoms method (EAM) potential were employed to simulatethe structures and binding energies of copper clusters. When n=2, the simulative value did not accord with the experimental result. Therefore, we corrected the parameters of EAM potential based on the experimental value of Cu2. Then the structures and binding energies of Cun(n=2—21, 35 and 55) were simulated. The results show that the values simulated by corrected parameters accorded with the wellknown ones for n<21; but in contrast the uncorrected parameters could represent copper clusters better for n≥21. So we conclude that corrected parameters were only fit for smaller copper clusters.
The Monte Carlo (MC) and embeddedatoms method (EAM) potential were employed to simulatethe structures and binding energies of copper clusters. When n=2, the simulative value did not accord with the experimental result. Therefore, we corrected the parameters of EAM potential based on the experimental value of Cu2. Then the structures and binding energies of Cun(n=2—21, 35 and 55) were simulated. The results show that the values simulated by corrected parameters accorded with the wellknown ones for n<21; but in contrast the uncorrected parameters could represent copper clusters better for n≥21. So we conclude that corrected parameters were only fit for smaller copper clusters.
2007, 24(1): 80-84.
doi: 10.11804/NuclPhysRev.24.01.080
Abstract:
The average neutron population necessary for sponsoring a persistent fission chain in a multiplying system, is discussed. In the point reactor model, the probability function (n, t0, t) of a source neutron at time t0 leading to n neutrons at time t is dealt with. The nonlinear partial differential equation for the probability generating function G(z; t0, t) is derived. By solving the equation, we have obtained an approximate analytic solution for a slightly prompt supercritical system. For the pulse reactor GodivaⅡ, the mean value of finite fission chain lengths is estimated in this work and shows that the estimated value is reasonable for the experimental analysis.
The average neutron population necessary for sponsoring a persistent fission chain in a multiplying system, is discussed. In the point reactor model, the probability function (n, t0, t) of a source neutron at time t0 leading to n neutrons at time t is dealt with. The nonlinear partial differential equation for the probability generating function G(z; t0, t) is derived. By solving the equation, we have obtained an approximate analytic solution for a slightly prompt supercritical system. For the pulse reactor GodivaⅡ, the mean value of finite fission chain lengths is estimated in this work and shows that the estimated value is reasonable for the experimental analysis.
甘公网安备 62010202000723号