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Parameter estimation, which undertakes one of the vital missions in quantum metrology, has attracted a lot of attention in recent years. A large number of investigations on the frequency estimation have been carried out. Most of them are based on Cramér-Rao bound estimation approach in which almost perfect knowledge of the parameter to be estimated is given. In reality, however, one has inadequate prior knowledge about the parameter to be estimated. Then the Bayesian estimation approach in which we can perform the estimation even if we only have partial prior information about the parameter would be an ideal choice. Prior information about the parameter can play a significant role in Bayesian statistical inference. So it is interesting to know how the prior knowledge affects the estimation accuracy in the estimation process. In the solid-state realization of probe system, material-specific fluctuations typically lead to the major contribution to the intrinsic noise. Then it is interesting to study the effects of colored noise on the quantum parameter estimation. In this work, we study the inhibitory effects of prior probability distribution of the parameter to be estimated on the effects of colored noise under the framework of Bayesian parameter estimation theory. In particular, we estimate the intensity of a magnetic field by adopting a spin-1/2 system which is influenced by the colored noise with 1/fα spectrum. To evaluate the accuracy of estimation, we obtain the Bayes cost analytically which can be applied to the noisy channels. We mainly focus on the inhibitory effect of prior probability distribution of measured parameter on the non-Gaussianity of noise. We find that for the case of broad prior frequency distribution, the influence of non-Gaussianity on the estimation is very weak. While for the case of narrow prior frequency distribution, the influence of non-Gaussianity on the estimation is strong. That means that in the Bayesian approach, when we have enough prior information about the frequency, the non-Gaussianity can conduce to the improvement of the accuracy of the estimation of the frequency. When we lose the prior information, we also lose the improvement of the accuracy from the non-Gaussianity. The uncertainty of the prior information tends to eliminate the effects of the non-Gaussianity of the noise.

We consider two two-level atoms, interacting with two independent dissipative cavities, each of which is driven by an external source. The two cavity fields are both initially prepared in the coherent states, and the two two-level atoms are initially prepared in the singlet state |� i = (|egi | gei)/ p 2. We investigate the influence of the damping constant �, the intensity of the external sources F, and the relative difference of the atomic couplings r on the entanglement between the two atoms. In the dispersive approximation, we find that the entanglement between the two atoms decreases with the time evolution, and the decreasing rate of entanglement depends on the values of F/�, �/!, and r. For the given small values of F/� and �/!, on the one hand, the increasing of r favors entanglement decreasing of the atomic system, on the other hand, when r ! 1 the entanglement decreasing becomes slower. With the increasing of the value of �/!, the influence of r on the decreasing rate of entanglement becomes smaller, and gradually disappears for the big value of �/!.

We propose an experimentally feasible teleportation scheme with three-atom W-class state, which was first proposed by Agrawal and Pati [P. Agrawal and A. Pati, Phys. Rev. A 74 (2006) 062320], in cavity QED. In this scheme atoms interact simultaneously with a nonresonant cavity and there is no energy exchange between the atoms and the cavity. Thus it is insensitive to the cavity decay, which is of importance in view of experiment.

We investigate the influence of the initial mixture of qubits and the dissipation on the entanglement transfer from three-qubit Greenberger–Horne–Zeilinger (GHZ) and W state fields to three matter qubits, which are trapped in three spatially separated cavities. We find that at gt≈11.07, the entanglement transfer can be almost complete no matter what state the qubits are initially prepared in. When the dissipation is taken into account, we find that the spontaneous emission plays the similar role to the cavity damping in the entanglement transfer, and the decay rate of the GHZ state is larger than that of the W state.

Two charge qubits being coupled to a damped cavity with dierent couplings are considered. The dynamical evolution of the entanglement between the two qubits is demonstrated analytically or numerically. It is found that with the cavity dissipation, the steady entanglement between the two qubits can be achieved. The two qubits being initially in the separable and most mixed state can be easily induced to a steady entangled state, and the relative dierence of the couplings can be used to enhance the steady entanglement between the two charge qubits. of the qubits cou- plings on the generation of the entanglement between the two qubits. We adopt the method proposed by Peres (17) and Horodecki (18) in terms of the negative eigenvalues of the partial transposition of the density matrix of the bi- partite system, to measure the degree of the entanglement between the two qubits. We find that in the presence of the cavity dissipation, the steady entanglement between the two qubits can be achieved; and the two qubits can be more easily entangled when they are initially in the most mixed state than in some pure states. We also find that the entanglement between the two charge qubits is maxi- mized for an optimal value of the relative dierence of the qubits couplings, and stronger entanglement between the two charge qubits can be generated by choosing the right strength of the relative dierence

Two charge qubits located inside a damped driven cavity is considered. The dynamical evolution of the entanglement between the two qubits is demonstrated analytically or numerically. It is found that with the cavity dissipation, the steady entanglement between the two qubits is sensitive to the initial state of the qubits, but independent of the cavity field's initial state. The two qubits initially in the separable and most mixed state can be more easily entangled. The external field can be used to enhance the steady entanglement between the two charge qubits.

The entanglement of two atomic qubits, which are coupled to a coherent state field with different couplings, is studied. The dynamical evolution of the concurrence, which measures the degree of the entanglement between the two qubits, is plotted versus the scaled time gt. It is found that the two qubits can be entangled by the coherent state field even when they are initially prepared in the most mixed state, and for very weak field, the most mixed state can be more easily entangled than some pure states. It is also found that the entanglement between the qubits sensitively depends on the relative difference of the atomic couplings and the mean photon number of the field.

To rationally develop low permeability reservoir, enhanced oil recovery, Changqing Oilfield launched a special low permeability oil field development studies. Based Changqing oilfield Yanhewan block this typical ultra-low permeability reservoir, use the numerical simulation method simulate the instability of water injection and gas injection alternating different effects of the development. The simulation results show that injection cycle in the early development of poor results, but the technique ultimately better results in the development of continuous injection; Gas-water cycle alternating six months of the development of better results in alternating cycles of three months, After the first injection of gas injection in better after the first injection of gas injection development effect, the study of the block for the rational development of a new approach.

In order to reveal the differentiation characteristics of organelles of ciliates under different physiological status, the cellular ultrastructure of Urostyla grandis was studied by transmission electron microscopy. In the resting cells most ciliary shafts, kinetosomes and sub-pellicle microtubules were resorbed, and the endoplasmic reticulum (ER) disappeared with the autophagocytosis taking place within the cytoplasm. As well, the nuclear matrix of the macronucleus was extruded into the cytoplasm, forming pseudopodia-like structures with large quantities of heterochromatin (CH) attached to the inner nuclear membrane. During excystment, membraneous structures developed and gradually increased in number to form the ER. Autophagic vacuoles (AVs) appeared containing mitochondria, paraglycogen particles (PGP), membranous structures, etc. Moreover, the number of nucleoli decreased with the chromatin, condensing in parallel with the process of recombination. Based on these observations, it could be concluded that the de-differentiation of microtubular organelles and the changes occurring in macronuclei in the resting Urostyla grandis, as well as the differentiation of cytoplasmic organelles, digestion by AVs, and the recombination of chromatin during excystment, are not similar to events that occur in non-kinetosome-resorbing cysts (NKR).