Teleportation for atomic entangled state by entanglement swapping with separate measurements in cavity QED

Experimentally feasible scheme for teleportation of atomic entangled state via entanglement swapping is proposed in cavity quantum electrodynamics (QED) without joint Bell-state measurement (BSM). In the teleportation processes the interaction between atoms and a single-mode nonresonant cavity with the assistance of a strong classical driving field substitute the joint measurements. The discussion of the scheme indicates that it can be realized by current technologies.Comment: 5 pages, no figur

A Benchmark Dataset for Understandable Medical Language Translation

In this paper, we introduce MedLane -- a new human-annotated Medical Language translation dataset, to align professional medical sentences with layperson-understandable expressions. The dataset contains 12,801 training samples, 1,015 validation samples, and 1,016 testing samples. We then evaluate one naive and six deep learning-based approaches on the MedLane dataset, including directly copying, a statistical machine translation approach Moses, four neural machine translation approaches (i.e., the proposed PMBERT-MT model, Seq2Seq and its two variants), and a modified text summarization model PointerNet. To compare the results, we utilize eleven metrics, including three new measures specifically designed for this task. Finally, we discuss the limitations of MedLane and baselines, and point out possible research directions for this task

Fractal pore and its impact on gas adsorption capacity of outburst coal: Geological significance to coalbed gas occurrence and outburst

Pore structure and methane adsorption of coal reservoir are closely correlated to the coalbed gas occurrence and outburst. Full-scale pore structure and its fractal heterogeneity of coal samples were quantitatively characterized using low-pressure N2 gas adsorption (LP-N2GA) and high-pressure mercury intrusion porosimetry (HP-MIP). Fractal pore structure and adsorption capacities between outburst and nonoutburst coals were compared, and their geological significance to gas occurrence and outburst was discussed. The results show that pore volume (PV) is mainly contributed by macropores ( \u3e 1000 nm) and mesopores (100-1000 nm), while specific surface area (SSA) is dominated by micropores ( \u3c 10 nm) and transition pores (10 - 100 nm). On average, the PV and SSA of outburst coal samples are 4.56 times and 5.77 times those of nonoutburst coal samples, respectively, which provide sufficient place for gas adsorption and storage. The pore shape is dominated by semiclosed pores in the nonoutburst coal, whereas open pores and inkbottle pores are prevailing in the outburst coal. The pore size is widely distributed in the outburst coal, in which not only micropores are dominant, but also, transition pores and mesopores are developed to a certain extent. Based on the data from HP-MIP and LP-N2GA, pore spatial structure and surface are of fractal characteristics with fractal dimensions Dm1 (2.81 - 2.97) and Dn (2.50 - 2.73) calculated by Menger model and Frenkel-Halsey-Hill (FHH) model, respectively. The pore structure in the outburst coal is more heterogeneous as its Dn and Dm1 are generally larger than those of the nonoutburst coal. The maximum methane adsorption capacities (VL: 15.34 - 20.86 cm 3 / g) of the outburst coal are larger than those of the nonoutburst coal (VL : 9.97-13.51cm 3 / g). The adsorptivity of coal samples is governed by the micropores, transition pores, and Dn because they are positively correlated with the SSA. The outburst coal belongs to tectonically deformed coal (TDC) characterized by weak strength, rich microporosity, complex pore structure, strong adsorption capacity, but poor pore connectivity because of inkbottle pores. Therefore, the area of TDC is at high risk for gas outburst as there is a high-pressure gas sealing zone with abundant gas enrichment but limited gas migration and extraction

The effects of manual airing strategies and architectural factors on the indoor air quality in college classrooms: a case study

In China, natural ventilation is a common way of improving indoor air quality (IAQ) in college classrooms. However, until now, the effects of both manual airing strategies and architectural factors on IAQ in classrooms have not been well explored. The present work aimed to investigate the effect of manual airing strategies, such as opening doors and opening exterior or interior windows, on the concentrations of both carbon dioxide (CO_{2}) and fine particulate matter (PM_{2.5}) in classrooms using field measurements. Through simulation, the effects of floor level, room orientation and the height of interior windows on CO_{2} concentration were also analysed. The results of this study revealed that (1) simultaneously opening doors and exterior windows or opening the doors alone could effectively reduce the indoor CO2 concentration, but the same effect could not be achieved by opening interior windows only; (2) the indoor PM_{2.5} concentration was primarily affected by the level of outdoor PM_{2.5}, and it may exceed the recommended limit by 33% when the outdoor pollution level is high, even with closed doors and windows; and (3) in winter, both floor level and classroom orientation exerted a significant influence on the indoor CO_{2} concentration, but the height of interior windows had no effect

Model-based downdraft biomass gasifier operation and design for synthetic gas production

In this study, three-phase flow model together with a thermal-equilibrium model was developed to study the operation of downdraft biomass gasifiers. Gasification experiments were conducted to obtain pyrolysis kinetics and validate the models. A good agreement was found between experiment data and model predictions, in terms of syngas composition and temperature, respectively. Kinetics based on experimental study improves the accuracy of simulation. The thermal-equilibrium model was applied to study the effects of air to biomass ratio on gas composition, LHV (lower heating value), and temperature. The 3D multiphase flow model was applied to investigate the spatial distributions of various parameters (i.e. pressure, gas velocity, temperature, and gas composition) inside the gasifier that are critical to the design of gasifier. A rough division of four gasification zones was determined based on temperature profile. It was also found that the cold gas efficiency was around 63% based on CFD (computational fluid dynamic) simulation. The temperature distributions could be used to guide the application of heat resistant materials inside the gasifier. In addition, the simulation results indicated that blockage of the gasifier has a high chance to occur at the top of reduction bell when using feedstock of high metal contents. Effects of reduction bell dimension and operation conditions on the temperature distribution and syngas production were also investigated by the 3D CFD model, which sheds light on the improvement of the design and operation of reactor. The syngas production could be enhanced by varying the size of reduction bell

Evolution from unconventional spin density wave to superconductivity and a novel gap-like phase in NaFe1-xCoxAs

Similar to the cuprate high TC superconductors, the iron pnictide superconductors also lie in close proximity to a magnetically ordered phase. A central debate concerning the superconducting mechanism is whether the local magnetic moments play an indispensable role or the itinerant electron description is sufficient. A key step for resolving this issue is to acquire a comprehensive picture regarding the nature of various phases and interactions in the iron compounds. Here we report the doping, temperature, and spatial evolutions of the electronic structure of NaFe1-xCoxAs studied by scanning tunneling microscopy. The spin density wave gap in the parent state is observed for the first time, which shows a strongly asymmetric lineshape that is incompatible with the conventional Fermi surface nesting scenario. The optimally doped sample exhibits a single, symmetric energy gap, but in the overdoped regime another asymmetric gap-like feature emerges near the Fermi level. This novel gap-like phase coexists with superconductivity in the ground state, persists deep into the normal state, and shows strong spatial variations. The characteristics of the three distinct low energy states, in conjunction with the peculiar high energy spectra, suggest that the coupling between the local moments and itinerant electrons is the fundamental driving force for the phases and phase transitions in the iron pnictides.Comment: 4 figures + supplementary informatio

On the Morphology, Structure and Field Emission Properties of Silver-Tetracyanoquinodimethane Nanostructures

Silver-tetracyanoquinodimethane(Ag-TCNQ) nanostructured arrays with different morphologies were grown by an organic vapor-transport reaction under different conditions. The field emission properties of nanostructured arrays were studied systematically. Their morphology and crystal structure were characterized by SEM and XRD, respectively. It was found that the field emission properties were strongly dependent on the reaction temperature and the initial Ag film thickness. The lowest turn-on field with 10-nm-thick silver film is about 2.0 V/μm, comparable to that of carbon nanotubes. The film crystal structure and the morphology are contributed to the final emission performance

Coherent population transfer between uncoupled or weakly coupled states in ladder-type superconducting qutrits

Stimulated Raman adiabatic passage offers significant advantages for coherent population transfer between uncoupled or weakly coupled states and has the potential of realizing efficient quantum gate, qubit entanglement and quantum information transfer. Here we report on the realization of the process in the superconducting Xmon and phase qutrits—two ladder-type three-level systems in which the ground state population is coherently transferred to the second excited state via the dark state subspace. We demonstrate that the population transfer efficiency is no less than 96% and 67% for the two devices, which agree well with the numerical simulation of the master equation. Population transfer via stimulated Raman adiabatic passage is significantly more robust against variations of the experimental parameters compared with that via the conventional resonant π pulse method. Our work opens up a new venue for exploring the process for quantum information processing using the superconducting artificial atoms.This work was supported by the Ministry of Science and Technology of China (Grant Nos. 2011CBA00106, 2014CB921202, and 2015CB921104) and the National Natural Science Foundation of China (Grant Nos. 91321208, 11222437, and 11161130519). S. Han acknowledges support by the US NSF (PHY-1314861)