To study the performance of the compressor in the HFC125 heat pump system, the volumetric and isentropic efficiencies of a variable speed compressor with pendular pistons were measured with the developed experimental system of HFC125 heat pump in the frequency range of 15-115Hz. The result indicted that there were high volumetric and isentropic efficiencies for the compressor in every frequency. A new model for the calculation of volumetric efficiency and isentropic efficiency were proposed in this paper, and the 146 experimental data of the volumetric and isentropic efficiencies were fitted with the new model. For the volumetric and isentropic efficiencies, the average absolute deviations were 1.749% and 2.815%, respectively, and the maximum deviations were 5.397% and 6.793%, respectively. It could be known that the new model could describe accurately the performance of the variable speed compressor with pendular pistons.

Isentropic process

Volumetric efficiency

Source

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Femtosecond strong-field coherent control of nonresonant ionization with shaped pulses

Chinese Physics B (2019)

Qiu-Nan Tong Zhenzhong Lian Liang Zhao Hongxia Qi Zhou Chen

The strong-field coherent control of the nonresonant ionization of nitrous oxide using shaped pulses is investigated. We study the dependence of periodic coherent oscillation of the total ionization yield on the variation of laser phase parameters. The physical mechanism of the strong-field coherent control is investigated experimentally and theoretically by the nonresonant spectral phase interferences in the frequency domain. We show that the intense shaped pulses with broadband and off-resonance can be used as a robust strong-field coherent control method.

Coherent control

Oscillation (cell signaling)

Tunnel ionization

10.1088/1674-1056/28/3/033201

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Quantum control of field-free molecular orientation

Physical Chemistry Chemical Physics (2023)

Qian-Qian Hong Zhenzhong Lian Chuan‐Cun Shu Niels E. Henriksen

This perspective offers valuable insights into the methods and techniques utilized to accomplish field-free molecular orientation. It also highlights the recent advancements in the precise control of molecular orientation at ultracold temperatures.

Quantum Control

10.1039/d3cp03115b

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Tracing the Coherent Manipulation of Rotational Dynamics by Shaped Femtosecond Pulse-Induced Two-Dimensional Rotational Coherent Spectrum

The Journal of Physical Chemistry A (2021)

Zhenzhong Lian Hongxia Qi Juan Li Jinqiu Bo Jiannan Deng

The temporal delayed orthogonal pulse pairs generated by the phase shaping technique are used to study the coherent control of the rotational wave packet dynamics in air. By continuously changing the intrapulse delay of the pump pulse, we measured the corresponding revival signals and obtained a two-dimensional rotational coherent spectrum (2D RCS). An additive property of the rotational dynamics is observed from the revival signals. Moreover, combining with the coherent control model, we find that the 2D RCS can be used to demonstrate the control over the underlying Raman rotational excitation. A beat frequency-dependent oscillation of each rotational transition is obtained. The transition process is revealed from the Fourier transformation about the pump delay. The scheme of this work can be used for further control and detection of the rotational wave packet and can be extended to other molecular dynamic researches.

Rotational dynamics

Dynamics

Tracing

Rotational spectrum

10.1021/acs.jpca.0c09244

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Measurement of the $D^{*}$ longitudinal polarization in $B^0\to D^{*-}τ^{+}ν_τ$ decays

arXiv (Cornell University) (2023)

R. Aaij A. S. W. Abdelmotteleb C. Abellán Beteta F. Abudinén T. Ackernley

The longitudinal polarization fraction of the $D^{*}$ meson is measured in $B^0\to D^{*-}\tau^{+}\nu_{\tau}$ decays, where the $\tau$ lepton decays to three charged pions and a neutrino, using proton-proton collision data collected by the LHCb experiment at center-of-mass energies of 7, 8 and 13 TeV and corresponding to an integrated luminosity of 5 fb$^{-1}$. The $D^{*}$ polarization fraction $F_{L}^{D^{*}}$ is measured in two $q^{2}$ regions, below and above 7 GeV$^{2}/c^{4}$, where $q^{2}$ is defined as the squared invariant mass of the $\tau\nu_{\tau}$ system. The $F_{L}^{D^{*}}$ values are measured to be $0.51 \pm 0.07 \pm 0.03$ and $0.35 \pm 0.08 \pm 0.02$ for the lower and higher $q^{2}$ regions, respectively. The first uncertainties are statistical and the second systematic. The average value over the whole $q^{2}$ range is: $$F_{L}^{D^{*}} = 0.43 \pm 0.06 \pm 0.03.$$ These results are compatible with the Standard Model predictions.

Invariant mass

10.48550/arxiv.2311.05224

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Manipulation of matter with shaped-pulse light field and its applications

Advances in Physics X (2021)

Hongxia Qi Zhenzhong Lian Dehou Fei Zhou Chen Zhan Hu

This review focuses on the properties of the light fields that are more useful in applications. We review recent means of generating shaped-pulse light field, by which matters can be steered toward the desired products, thereby allowing the coherent control in terms of effectiveness, selectivity and manipulation. Applications of these light fields are discussed, including bioscience, laser machining, novel material fabrication, trace material detection and military.

Light Field

TRACE (psycholinguistics)

10.1080/23746149.2021.1949390

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Citations (9)