5,194 research outputs found
Ethyl 3-(4-chlorophenyl)-1-(2-oxo-2-phenylethyl)-1H-pyrazole-5-carboxylate
In the title compound, C20H17ClN2O3, the dihedral angles between the pyrazole ring and the substituted and unsubstituted benzene rings are 3.64 (13) and 81.15 (17)°, respectively. Molecules are connected via three pairs of weak hydrogen bonds into a centrosymmetric dimer. The crystal structure is stabilized by intermolecular C—H⋯O and C—H⋯π interactions
Finite volume effects of the Nambu-Jona-Lasinio model with the running coupling constant
With the Schwinger's proper-time formalism of the Nambu-Jona-Lasinio model,
we investigate the finite volume effects in the presence of magnetic fields.
Since the coupling constant can be influenced by strong magnetic fields,
the model is solved with a running coupling constant which is fitted by
the lattice average and difference .
The investigation mainly focuses on the constituent quark mass and the thermal
susceptibility depending on the magnetic fields, the temperatures and the
finite sizes. For the model in finite or infinite volume, the magnetic fields
can increase the constituent quark mass while the temperatures can decrease it
inversely. There is a narrow range of the box length that makes the effects of
finite volume perform prominently. The model will behave close to infinite
volume limit for larger box length. It is shown that the influence of finite
volume can be changed by magnetic fields and temperatures. Finally, we discuss
the thermal susceptibility depending on the temperature in finite volume in the
presence of magnetic fields.Comment: 13 pages, 6 figure
Decoy State Quantum Key Distribution With Modified Coherent State
To beat PNS attack, decoy state quantum key distribution (QKD) based on
coherent state has been studied widely. We present a decoy state QKD protocol
with modified coherent state (MCS). By destruction quantum interference, MCS
with fewer multi-photon events can be get, which may improve key bit rate and
security distance of QKD. Through numerical simulation, we show about 2-dB
increment on security distance for BB84 protocol.Comment: 4 pages, 4 figure
An immediate-return reinforcement learning for the atypical Markov decision processes
The atypical Markov decision processes (MDPs) are decision-making for maximizing the immediate returns in only one state transition. Many complex dynamic problems can be regarded as the atypical MDPs, e.g., football trajectory control, approximations of the compound Poincaré maps, and parameter identification. However, existing deep reinforcement learning (RL) algorithms are designed to maximize long-term returns, causing a waste of computing resources when applied in the atypical MDPs. These existing algorithms are also limited by the estimation error of the value function, leading to a poor policy. To solve such limitations, this paper proposes an immediate-return algorithm for the atypical MDPs with continuous action space by designing an unbiased and low variance target Q-value and a simplified network framework. Then, two examples of atypical MDPs considering the uncertainty are presented to illustrate the performance of the proposed algorithm, i.e., passing the football to a moving player and chipping the football over the human wall. Compared with the existing deep RL algorithms, such as deep deterministic policy gradient and proximal policy optimization, the proposed algorithm shows significant advantages in learning efficiency, the effective rate of control, and computing resource usage
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