多线程并行在CHF一体化开发系统中的应用

CHF(Critical Heat Flux)一体化开发系统根据临界热流密度的实验数据与子通道计算进行相互对比和统计学分析,最终对CHF经验关系式进行修正和优化。由于CHF一体化开发系统的运行效率偏低,且反复调用子通道计算模块,所以引入多线程并行编程技术来加速计算。通过OpenMP和POSIX线程两种编程方案取得不同的加速效果,区别在于后者编程难度更大。19组实验数据问题的CHF一体化开发系统运行效率被提升5倍左右,接近加速的理论上限。

Efficient Scheme for One-Way Quantum Computing with Radiofrequency SQUID Qubits by Adiabatic Passage

We proposed an efficient scheme for constructing a quantum controlled phase-shift gate and generating thecluster states with rf superconducting quantum interference devices (SQUIDs)coupled to a microwave cavity throughadiabatic evolution of dark eigenstates.During the operation,the spontaneous emission is suppressed since the rf SQUIDsare always in the three lowest flux states.Considering the influence from the cavity decay with achievable experimentalparameters,we numerically analyze the success probability and the fidelity for generating the two-SQUID maximallyentangled state and the controlled phase-shift gate by adiabatic passage.

Pade Expansion and Nucleon-Nucleon Scattering in Coupled Channels

We extend our Pade-aided analysis of the nonperturbative renormalization of nucleon-nucleon scatteringto the case of coupled channels.

Model Potential Calculations of Oscillator Strength Spectra of Rydberg Li Atoms in External Fields

By combining the B-spline basis set with model potential (B-spline + MP),we present oscillator strengthspectra of Rydberg Li atoms in external fields.The photoabsorption spectra are analyzed.Over the narrow energyranges considered in this paper,the structure of the spectra can be independent of the initial state chosen for a givenatom.Our results are in good agreement with previous high-precision experimental data and theoretical calculations,where the R-matrix approach together with multichannel quantum defect theory (R-matrix+MQDT) was used.It issuggested that the present methods can be applied to deal with the oscillator strength spectra of Rydberg atoms incrossed electric and magnetic fields.

Constructing Non-binary Asymmetric Quantum Codes via Graphs

The theory of quantum error correcting codes is a primary tool for fighting decoherence and other quantum noise in quantum communication and quantum computation. Recently, the theory of quantum error correcting codes has developed rapidly and been extended to protect quantum information over asymmetric quantum channels, in which phase-shift and qubit-flip errors occur with different probabilities. In this paper, we generalize the construction of symmetric quantum codes via graphs (or matrices) to the asymmetric case, converting the construction of asymmetric quantum codes to finding matrices with some special properties. We also propose some asymmetric quantum Maximal Distance Separable (MDS) codes as examples constructed in this way.

Theoretical Analysis of Neutron Double-Differential Cross Sections of n ＋^9Be Reactions

By using the nuclear reaction model for light nuclei, the calculations of the double-differential cross sections of outgoing neutrons from n ＋^9Be reactions are performed. The total outgoing neutrons are only come from the （n, 2n）2a reaction channel. The （n, 2n）2a reaction channel is achieved through six different reaction approach, which are illustrated in this paper. The calculated results agree very well with the measured data at En = 7.1, 8.09, 8.17, 9.09, 9.97 and 10.26 MeV, because the updated level schemes related to the n ＋ ^9Be reactions have been employed in this calculations.

Effects of noisy quantum channels on one-qubit rotation gate

We investigate the effects of noisy quantum channels on the entanglement of cluster states and one way quantum computational gates.We take a basic model,the rotational gate about x axis based on the cluster state,in order to get the most essential effects of the paradigmatic noisy quantum channels.The entanglement of cluster states in the noisy channels and the fidelity between the rotated state without noisy channel and that with noisy channel are calculated.

Analysis of Internal Cooling Geometry Variations in Gas Turbine Blades

The present investigation analyzes the effects of major geometrical modifications to the interior of a convectioncooled gas turbine rotor blade. The main focus lies on the flow of the leading edge channels and the impact on theheat transfer. An experimental approach is performed with flow visualization via paint injection into water. Alsonumerical calculations are carried out in two sets, on the one hand water calculations accompanying the experimentsand on the other hand conjugate heat transfer calculations under realistic engine conditions. The latter calculationsare still ongoing delivering preliminary results.Five geometry configurations are investigated, three of them with differing turbulator arrangements in the leadingedge channels. The operating point of the base configuration is set to Re = 50,000 at the inlet while for the modifiedgeometries the pressure ratio is held constant compared to the base.Among several investigated configurations one could be identified that leads to a heat transfer enhancement inone leading edge channel 7 % larger compared to the base.

Quantum computation with surface-state electrons by rapid population passages

Quantum computation requires coherently controlling the evolutions of qubits.Usually,these manipulations are implemented by precisely designing the durations(such as theπ-pulses)of the Rabi oscillations and tunable interbit coupling.Relaxing this requirement,herein we show that the desired population transfers between the logic states can be deterministically realized(and thus quantum computation could be implemented)both adiabatically and non-adiabatically,by performing the duration-insensitive quantum manipulations.Our proposal is specifically demonstrated with the surface-state of electrons floating on the liquid helium,but could also be applied to the other artificially controllable systems for quantum computing.

Energetic electron flux distribution model in the inner and middle magnetosphere

Based on the magnetospheric kinetic theory, a model is developed to specify the flux of energetic electrons in the inner and middle magnetosphere. Under the assumption of adiabatic motion and isotropic particle distribution maintained by pitch-angle scattering, the model calculates the electron flux by following bounce-averaged electric field, gradient, and curvature drift in the time dependent electric and magnetic field, meanwhile it counts the electron loss caused by pitch angle scattering. Using the model, the clectron flux distribution during a magnetic storm was calculated and compared with the observation data from the geosynchronous orbit. It is shown that the model can successfully reproduce most of the major electron flux enhancements observed at the geosynchronous orbit and generally tracks the satellite data well. The rms errors of the modeled logarithm of flux are between 0.5-1.0.

Stark-Chirped Rapid Adiabatic Passage in Presence of Dissipation for Quantum Computation

Stark-chirped rapid adiabatic passage(SCRAP) is an important technique used for coherent quantum controls. In this paper we investigate how the practically-existing dissipation of the system influences on the efficiency of the passage, and thus the fidelities of the SCRAP-based quantum gates. With flux-biased Josephson qubits as a specifical example, our results show clearly that the efficiency of the logic gates implemented by SCRAP are robust against the weak dissipation. The influence due to the non-adiabtic transitions between the adiabatic passages is comparatively significantly small. Therefore, the SCRAP-based logic gates should be feasible for the realistic physical systems with noises.