In the present paper, we study the zero-temperature phase diagram of the doped perovskite manganitesat filling x = 0.5 by the real-space Hartree-Fock approximation method. Our purpose is to resolve a controversialissu...In the present paper, we study the zero-temperature phase diagram of the doped perovskite manganitesat filling x = 0.5 by the real-space Hartree-Fock approximation method. Our purpose is to resolve a controversialissue arising recently on the origin of the charge ordered phases in these systems. We find that the antiferromagneticsuperexchange interaction between the localized spins plays the central role in producing the concerned phases. Ourresults confirm some speculations on this issue.展开更多
In the present paper, we continue our investigation on the antiferromagneticorigin of the charge order observed in the halt-doped manganese. By introducing aSu-Schrieffer-Heeger (SSH) type of perturbation interaction ...In the present paper, we continue our investigation on the antiferromagneticorigin of the charge order observed in the halt-doped manganese. By introducing aSu-Schrieffer-Heeger (SSH) type of perturbation interaction to the double-exchange Hamiltonian, wecalculate again its ground-state phase diagram at Glling x = 0.5 by the unrestricted real-spaceHartree-Fock approximation method. We find that, as the SSH electron-phonon interaction increases,the charge order parameter decreases to zero rapidly but the CE-type antiferromagnetic order becomesmore stable. In other words, the charge order is much more fragile than the CE-type or theNeel-type antiferromagnetic orders under the electron-phonon perturbation. These results support theproposed theory in the recent publications that the charge order in these systems is induced by theantiferromagnetic correlations.展开更多
Different gestational age fetal follicles of Northeast China Fine-fleece Sheep were histologically studied. The results showed that boundaries between medulla and cortex was ambiguous at the eighth week and became obv...Different gestational age fetal follicles of Northeast China Fine-fleece Sheep were histologically studied. The results showed that boundaries between medulla and cortex was ambiguous at the eighth week and became obvious at the twelfth week. Primordial follicles could be found in 8-week fetal ovaries and some follicle cells became irregular cuboid in 12-week, but primary follicles could be found until 16-week. There was significant difference between 8-week and 12-week follicles in size (P < 0.01), most mitochondria were round, some diamond, irregular and juvenile ones could be found with the development of oocytes. Some of oocytes degenerated in each stage of development. The diameter of primary oocytes, primordial follicles and primordial follicular oocytes were larger in 12-16 weeks fetal ovaries than other times.展开更多
文摘In the present paper, we study the zero-temperature phase diagram of the doped perovskite manganitesat filling x = 0.5 by the real-space Hartree-Fock approximation method. Our purpose is to resolve a controversialissue arising recently on the origin of the charge ordered phases in these systems. We find that the antiferromagneticsuperexchange interaction between the localized spins plays the central role in producing the concerned phases. Ourresults confirm some speculations on this issue.
文摘In the present paper, we continue our investigation on the antiferromagneticorigin of the charge order observed in the halt-doped manganese. By introducing aSu-Schrieffer-Heeger (SSH) type of perturbation interaction to the double-exchange Hamiltonian, wecalculate again its ground-state phase diagram at Glling x = 0.5 by the unrestricted real-spaceHartree-Fock approximation method. We find that, as the SSH electron-phonon interaction increases,the charge order parameter decreases to zero rapidly but the CE-type antiferromagnetic order becomesmore stable. In other words, the charge order is much more fragile than the CE-type or theNeel-type antiferromagnetic orders under the electron-phonon perturbation. These results support theproposed theory in the recent publications that the charge order in these systems is induced by theantiferromagnetic correlations.
文摘Different gestational age fetal follicles of Northeast China Fine-fleece Sheep were histologically studied. The results showed that boundaries between medulla and cortex was ambiguous at the eighth week and became obvious at the twelfth week. Primordial follicles could be found in 8-week fetal ovaries and some follicle cells became irregular cuboid in 12-week, but primary follicles could be found until 16-week. There was significant difference between 8-week and 12-week follicles in size (P < 0.01), most mitochondria were round, some diamond, irregular and juvenile ones could be found with the development of oocytes. Some of oocytes degenerated in each stage of development. The diameter of primary oocytes, primordial follicles and primordial follicular oocytes were larger in 12-16 weeks fetal ovaries than other times.
