[en] This article discusses the concept and types of dynamic scientific and technical intelligence, describes the characteristics and role of dynamic scientific and technical intelligence, and analyzes methods and procedures of dynamic scientific and technical intelligence research. Combined with the status quo of dynamic scientific and technical intelligence research in library of China Institute of Atomic Energy, this article makes some suggestions for strengthening dynamic scientific and technical intelligence research. (authors)

[en] Pair production of the doubly charged leptons X^±± via vector boson fusion (γγ, Zγ and WW) at the large hadron collider is studied. Our numerical results show that the cross section via Zγ fusion is very small. For the center-of-mass energy √s=14 TeV and M_X = 200-650 GeV, the values of the cross sections σ_γγ and σ_ww are in the ranges of 5.2 fb-0.04 fb and 20.2 fb-1.2 fb, respectively. (authors)

[en] A quantum theory of Cherenkov radiation in a gas medium is established by means of first-order perturbation of quantum field theory. The results show that there are some different characteristics from Cherenkov radiation in liquids and solids. The main features of this Cherenkov radiation are the following: (1) A line spectrum, asymmetric profile and small red shift; (2) The radiation angle is independent of frequency and decreases along with the increase in the speed of the incident charged particles. (3) No speed threshold of the charged particles exists. (4) No matter whether the atom is in the ground state or an excited state, the probability of Cherenkov radiations coincides with the experiments

[en] Qubits A, B and C, initially prepared in a like-GHZ state, are distributed to three remote receivers through a decoherence environment. A weak measurement is firstly performed on each qubit before experiencing the decoherence channel, and then the receivers carry out a quantum measurement reversal on individual qubit after receiving them. The qubits’ entanglement is evaluated by means of negativity. The results show the pre- and post-measurements’ strength has an important influence on tripartite entanglement for the initially given state, and proper pre- and post-measurements’ strength always effectively improves tripartite entanglement, which is significant to protect entanglement from decoherence. (paper)

[en] We study the steady-state entanglement and heat current of two coupled qubits, in which two qubits are connected with two independent heat baths (IHBs) or two common heat baths (CHBs). We construct the master equation in the eigenstate representation of two coupled qubits to describe the dynamics of the total system and derive the solutions in the steady-state with stronger coupling regime between two qubits than qubit–baths. We do not make the rotating wave approximation (RWA) for the qubit–qubit interaction, and so we are able to investigate the behaviors of the system in both the strong coupling regime and the weak coupling regime, respectively. In an equilibrium bath, we find that the entanglement decreases with the bath temperature and energy detuning increasing under the strong coupling regime. In the weak coupling regime, the entanglement increases with coupling strength increasing and decreases with the bath temperature and energy detuning increasing. In a nonequilibrium bath, the entanglement without RWA is useful for entanglement at lower temperatures. We also study the heat currents of the two coupled qubits and their variations with the energy detuning, coupling strength and low temperature. In the strong (weak) coupling regime, the heat current increases (decreases) with coupling strength increasing when the temperature of one bath is lower (higher) than the other, and the energy detuning leads to a positive (negative) effect when the temperature is low (high). In the weak coupling regime, the variation trend of heat current is opposite to that of coupling strength for the IHB case and the CHB case. (paper)

[en] We analyze universal conditions where the l ₁ norm and relative entropy of coherence are amplified and frozen under identical bit-flip channels; that is, using pre-measurements (quantum weak measurements or quantum measurement reversals) on the systems before undergoing local bit-flip channels. With the option of quantum weak measurements or quantum measurement reversals, the measurement strength and the success probability are all determined by the initial state of the quantum system. (paper)

[en] We investigate quantum teleportation of a single-qubit state for the situation in which both qubits of the entangled channel are subjected to local structured reservoirs. We consider the effect of entanglement sudden death (ESD) of the channel on the average fidelity of the teleportation. It is shown the appearance of ESD leads to an abrupt variation of the fidelity of quantum teleportation. In addition, we show the fidelity exhibits oscillations in the non-Markovian reservoir due to the memory effect of the reservoir.

[en] The lower bounds of the evolution time between two distinguishable states of a system, defined as quantum speed limit time, can characterize the maximal speed of quantum computers and communication channels. We study the quantum speed limit time between the composite quantum states and their target states in the presence of nondissipative decoherence. For the initial states with maximally mixed marginals, we obtain the exact expressions of the quantum speed limit time which mainly depend on the parameters of the initial states and the decoherence channels. Furthermore, by calculating the quantum speed limit time for the time-dependent states started from a class of initial states, we discover that the quantum speed limit time gradually decreases in time, and the decay rate of the quantum speed limit time would show a sudden change at a certain critical time. Interestingly, at the same critical time, the composite system dynamics would exhibit a sudden transition from classical decoherence to quantum decoherence. (paper)

[en] The present studies show that any nonzero amount of coherence of a system can be converted into entanglement between the system and an incoherent ancillary system via incoherent operations. According to this conclusion, we study the process of converting coherence into entanglement via a unitary operation where the initial ancillary system is of different quantum state. We find that some other conditions should be satisfied in converting coherence into entanglement. We also study the conditions of coherence consumption of converting coherence into entanglement. (paper)

[en] We investigate the tripartite entanglement dynamics of three two-level atoms in a multi-mode vacuum field. By considering the influences of the interatomic distance and the initial condition on the lower bound of concurrence and the tripartite negativity, we show that an optimal interatomic distance can be found to minimize the collective damping. Interestingly, at the same optimal distance, the tripartite entanglement would be maximized in the open dynamics process. In the case of shorter interatomic distance, the tripartite entanglement can display the oscillatory behavior in the initial short-time limit and be trapped in a stationary value in the long-time limit. In addition, the tripartite entanglement for the general situation with different interatomic distances is also discussed. (paper)