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Variation of Two-photon Absorption Cross Sections and Optical Limiting of Compounds Induced by Static Electric Field

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Chinese Journal of Chemical Physics 2014年第3期27卷 259-264页

作者： yu-jin Zhang yu-zhi song Chuan-kui Wang College of Physics and Electronics Shandong Normal University Jinan 250014 China

By numerically solving the Maxwell-Bloch equations using an iterative predictor-corrector finite-difference time-domain technique, we investigate propagating properties of a few-cycle laser pulse in a 4,4＇-bis（di-n-butylamino） stilbene （BDBAS） molecular medium when a static electric field exists. Dynamical two-photon absorption （TPA） cross sections are obtained and optical limiting （OL） behavior is displayed. The results show that when the static electric field intensity increases, the dynamical TPA cross section is enhanced and the OL behavior is improved. Moreover, both even- and odd-order harmonic spectral components are generated with existence of the static electric field because it breaks the inversion symmetry of the BDBAS molecule. This work provides a method to modulate the nonlinear optical properties of the BDBAS compounds.

关键词： Static electric field Optical limiting Two-photon absorption Organic molecule

Phase State as a Limiting Case of SU(1,1) Coherent State

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Communications in Theoretical Physics 2009年第1期51卷 68-70页

作者： yu zhi-song FAN Hong-Yi Department of Physics Hubei Normal University Huangshi 435002 China Department of Material Science and Engineering University of Science and Technology of China Hefei 230026 China

We show that the Susskind-Glogower phase state is a limiting case of a kind of SU（1,1） coherent states. By analogy, based on the bipartite entangled state representation （ESR） we demonstrate that an appropriate SU（1,1） coherent state composed of the two-mode unitary phase operator e^i also leads to a new phase state in two-mode Fock space, e^i is diagonalized in the ESR.

关键词： phase state unitary phase operator bipartite entangled state representation SU(1 1) coherentstate

Solvent Effects on Two-Photon Absorption of Alkyne and Alkene π-bridging Chromophores

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Chinese Journal of Chemical Physics 2017年第1期30卷 63-70,I0001页

作者： Jing Li Chuan-kui Wang yu-zhi song College of Physics and Engineering Qufu Normal University Qufu 273165 China School of Physics and Electronics 5handong Normal University ginan 250014 China

The present work concerns the study of solvent effects on the geometrical structures, as well as one- and two-photon absorption （TPA） processes, for two series of alkyne and alkene π-bridging molecules, within the framework of the polarization continuum model. Particular emphasis was put on the characterization of solvent effects on the molecular geometrical structures and geometric distortion, which were measured by the bond-length-alternation parameter. The π centres in the compounds are seen to play a decisive role in increasing the TPA cross section and nonlinear optical properties. All studied molecules have relatively strong TPA characteristics, while the alkyne π-bridging ones yield larger TPA cross sections.

关键词： Nonlinear optics Two photon absorption Solvent effect Charge transfer Bond length alternation

Theoretical Analysis on Optical Limiting Properties of Newly Synthesized Graphene Oxide-Porphyrin Composites

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Chinese Journal of Chemical Physics 2015年第3期28卷 257-262,I0001页

作者： yu-jin Zhang Wen-jing Yang Jian-zhong Fan yu-zhi song Chuan-kui Wang College of Physics and Electronics Shandong Normal University Jinan 250014 China

Optical limiting （OL） properties and two-photon absorption （TPA） of a series of covalently linked graphene oxide-porphyrin composite materials have been investigated by numerically solving the rate equations and field intensity equation with an iterative predictor-corrector finite-difference time-domain technique in nanosecond time domain. Our results show that graphene oxide-porphyrin composites exhibit enhanced OL behavior and possess larger TPA cross section compared with individual porphyrins. Interestingly~ unlike the previous result that porphyrin with heavier central metal shows better nonlinear abilities than that with- out metal substitute, graphene oxide-metal free porphyrin composite has stronger nonlinear absorption properties compared with graphene oxide-metal porphyrin composite. The com- putational results are in reasonable agreement with the experimental ones. Special attention has been paid to the influence of thickness of the medium and pulse width on TPA cross sections, which presents that larger TPA cross sections are obtained as the medium is thicker or the pulse duration is wider.

关键词： Optical limiting Two-photon absorption Graphene oxide Porphyrin

Field-free molecular orientation steered by combination of super-Gaussian and THz half-cycle laser pulses

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Chinese Physics B 2019年第11期28卷 150-155页

作者： Qi-yuan Cheng yu-zhi song Qing-Tian Meng Medical Engineering Department Shandong Provincial Hospital Affiliated to Shandong UniversityJinan 250021China School of Physics and Electronics Shandong Normal UniversityJinan 250358China

The molecular orientation created by laser fields is important for steering chemical reactions. In this paper, we propose a theoretical scheme to manipulate field-free molecular orientation by using an intense super-Gaussian laser pulse and a time-delayed terahertz half-cycle pulse(THz HCP). It is shown that the degree of field-free orientation can be doubled by the combined pulse with respect to the super-Gaussian pulse or THz HCP alone. Moreover, different laser intensities, carrier envelop phases, shape parameters, and time delays have great influence on the positive and negative orientations, with other conditions unchanged. Furthermore, it is indicated that the maximum degree and direction of molecular orientation can be precisely controlled by half of the duration of the super-Gaussian pulse. Finally, by adjusting the laser parameters of the super-Gaussian laser pulse and THz HCP, the optimal results of negative orientation and corresponding rotational populations are obtained at different temperatures of the molecular system.

关键词： molecular orientation terahertz half-cycle pulse super-Gaussian pulse

Dynamics of molecular alignment steered by a few-cycle terahertz laser pulse

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Chinese Physics B 2022年第10期31卷 377-383页

作者： Qi-yuan Cheng yu-zhi song Deng-Wang Li zhi-Ping Liu Qing-Tian Meng Medical Engineering Department Shandong Provincial Hospital Affiliated to Shandong First Medical UniversityJinan 250021China School of Physics and Electronics Shandong Normal UniversityJinan 250358China Shandong Laibo Biotechnology Co. Ltd.Jinan 250101China School of Control Science and Engineering Shandong UniversityJinan 250061China

The field-free alignment of molecule Cl CN is investigated by using a terahertz few-cycle pulse(THz FCP)based on the time-dependent density matrix *** is shown that a high degree of molecular alignment can be obtained by changing the matching number of the THz FCPs in the adiabatic regime and the non-adiabatic *** matching number can affect both the maximum value of the alignment and the time at which it is *** is also found that a higher degree of alignment can be achieved by using the THz FCP at lower intensity and there exists an optimal threshold of molecular alignment with the increase of the field *** found is the frequency sensitive region in which the degree of maximum alignment can be enhanced greatly by modulating the center frequencies of different THz *** investigation demonstrates that comparing with a THz single-cycle pulse,a better result of the field-free alignment can be created by a THz FCP at a constant rotational temperature of molecule.

关键词： molecular alignment few-cycle terahertz pulse density matrix theory

Mucosa-associated lymphoid tissue lymphoma of the trachea treated with radiotherapy:A case report

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World Journal of Clinical Cases 2023年第7期11卷 1607-1614页

作者： Chan-Jun Zhen Ping Zhang Wen-Wen Bai yu-zhi song Jun-Li Liang Xue-Ying Qiao zhi-Guo Zhou Department of Radiation Oncology The Fourth Hospital of Hebei Medical UniversityShijiazhuang 050011Hebei ProvinceChina Nursing Department The Fourth Hospital of Hebei Medical UniversityShijiazhuang 050011Hebei ProvinceChina

BACKGROUND Mucosa-associated lymphoid tissue(MALT)lymphoma originates in the marginal zone of lymphoid *** is one of the most frequent non-gastrointestinal organs involved,here known as bronchus-associated lymphoid tissue(BALT)*** lymphoma of unknown etiology,and most patients are *** treatment of BALT lymphoma is *** SUMMARY A 55-year-old man admitted to hospital had a three-month history of progressively coughing up yellow sputum,chest stuffiness,and shortness of *** bronchoscopy revealed mucosal visible beaded bumps 4 cm from the tracheal carina at 9 o'clock and 3 o'clock,the right main bronchus,and the right upper lobe *** specimens showed MALT *** tomography virtual bronchoscopy(CTVB)showed uneven main bronchial wall thickening and multiple nodular *** lymphoma stage IE was diagnosed after a staging *** treated the patient with radiotherapy(RT)alone.A total dose of 30.6 Gy/17 f/25 d was *** patient had no obvious adverse reactions during *** CTVB was repeated after RT and showed that the right side of the trachea was slightly *** was repeated 1.5 mo after RT and again showed that the right side of the trachea was slightly *** CTVB showed no signs of *** patient now has no *** BALT lymphoma is an uncommon disease and shows good *** treatment of BALT lymphoma is *** recent years,less invasive diagnostic and therapeutic approaches have been *** was effective and safe in our *** use of CTVB could provide a noninvasive,repeatable,and accurate method in diagnosis and follow-up.

关键词： Mucosa-associated lymphoid tissue lymphoma Computed tomography virtual bronchoscopy Radiotherapy Prognosis Case Report

Tetraphenylethylene dicycle helicates: circularly polarized luminescence and chiral recognition based on emission wavelength change

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Science China Chemistry 2024年第11期67卷 3817-3824页

作者： zhi-Rong Xu Miao-Li Gao Ming Hu Wei yu Yan-song Zheng Key Laboratory of Material Chemistry for Energy Conversion and Storage Ministry of Education School of Chemistry and Chemical Engineering Huazhong University of Science and Technology

Chiral tetraphenylethylene(TPE) dicycle tetraaldehyde and TPE dicycle tetraacids bearing optically pure groups on the cycles were designed and synthesized. Due to the propeller-like conformation immobilization of TPE unit, this new class of TPE dicycle was resolved into M-and P-enantiomers, which could emit strong circular polarized luminescence(CPL). Interestingly,these TPE helicates displayed exceptional ability of molecule recognition. While the TPE dicycle tetraaldehyde could detect the microscale water in anhydrous tetrahydrofuran, the chiral TPE dicycle tetraacid could display different fluorescent color after interacting with two enantiomers of a wide variety of chiral amines including monoamines, diamines, and aminols, which could be applied to chiral recognition of these chiral amines. Furthermore, the emission wavelength of TPE dicycle tetraacid was found to change linearly with the enantiomer purity of chiral amine from enantiomer excess(ee) percent-100% to +100%, for the first time showing the potential for quantitative chiral analysis of chiral amines based on emission wavelength change. The emission wavelength was affected less by environmental factors than fluorescence intensity, which would enable the chiral analysis based on wavelength change with higher accuracy and repeatability.

关键词： TPE dicycle helicate CPL chiral recognition enantiomer excess analysis emission wavelength change

Beamline design for multipurpose muon beams at CSNS EMuS

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Nuclear Science and Techniques 2024年第5期35卷 1-12页

作者： Yang Hong Ying-Peng song Lu-Ping Zhou Jing-yu Tang zhi-Hao Zhou Nikolaos Vassilopoulos Institute of High Energy Physics Chinese Academy of Sciences(CAS)Beijing 100049China Spallation Neutron Source Science Center Dongguan 523803China University of Chinese Academy of Sciences Beijing 100049China Radiotherapy Physics and Technology Center Cancer CenterWest China HospitalSichuan UniversityChengdu 610041China Xi’an Jiaotong University Health Science Center Xi’an 710049China Department of Radiation Oncology First Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710049China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230027China

A new muon beam facility,called the Experimental Muon Source(EMuS),was proposed for construction at the China Spallation Neutron Source(CSNS).The design of the complex muon beamlines for the EMuS baseline scheme,which is based on superconducting solenoids,superferric dipoles and room-temperature magnets,is presented *** muon beams,including surface muons,decay muons and low energy muons,have been developed for multipurpose *** optics design and simulation results of the trunk beamline and branch beamlines are *** a proton beam power of 25 kW at a standalone target station that consists of a conical graphite target and high-field superconducting solenoids,the muon beam intensity in the trunk beamline varies from 10^(7)/s for surface muons to 10^(10)/s for high-momentum decay *** at the endstations,these values vary from 10^(5)/s for surface muons to 10^(8)/s for decay muons.

关键词： Surface muons Decay muons Muon beamline Superconducting solenoids Multi-channel electrostatic separator