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Theoretical studies of the proton transfer behaviors in molecular complexes analogous to catalytic triad of serine protease:Toward understanding the existence and significance of the low-barrier hydrogen-bond in enzymatic catalysis

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Science China Chemistry 2009年第2期52卷 131-136页

作者： LI Ping WANG WeiHua BI SiWei SONG Rui BU YuXiang College of Chemistry Science Qufu Normal UniversityQufu 273165China Key Laboratory of Colloid and Interface Chemistry(Shandong University) Ministry of EducationJinan 250100China

A representative acetate-(5-methylimidazole)-methanol system has been employed as a model of catalytic triad in serine protease to validate the formation processes of lowbarrier H-bonds(LBHB) at the B3LYP/6-311++G level of theory,and variable H-bonding characters from conventional ones to LBHBs have been represented along with the proceedings of proton transfer.Solvent effect is an important factor in modulation of the existence of an LBHB,where an LBHB(or a conventional H-bond) in the gas phase can be changed into a non-LBHB(an LBHB) upon solvation.The origin of the additional stabili-zation energy arising from the LBHB may be attributed to the H-bonding energy difference before and after proton transfer because the shared proton can freely move between the proton donor and proton acceptor.Most importantly,the order of magnitude of the stabilization energy depends on the studied systems.Furthermore,the nonexistence of LBHBs in the catalytic triad of serine proteases has been verified in a more sophisticated model treated using the ONIOM method.As a result,only the single proton transfer mechanism in the catalytic triad has been confirmed and the origin of the powerful catalytic efficiency of serine proteases should be attributed to other factors rather than the LBHB.

关键词： low-barrier H-bonds(LBHB) proton transfer catalytic triad

Predictions for proton and heavy ions induced SEUs in 65 nm SRAMs

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Journal of Semiconductors 2015年第11期36卷 69-72页

作者：杜守刚岳素格刘红侠范隆郑宏超 School of Microelectronics Xidian University Beijing Microelectronics Technology Institute Beijing University of Aeronautics & Astronautics

We report on irradiation induced single event upset（SEU） by high-energy protons and heavy ions. The experiments were performed at the Paul Scherer Institute, and heavy ions at the SEE irradiating Facility on the HI-13 Tandem Accelerator in China＇s Institute of Atomic Energy, Beijing and the Heavy Ion Research Facility in Lanzhou in the Institute of Modern Physics, Chinese Academy of Sciences. The results of proton and heavy ions induced（SEU） in 65 nm bulk silicon CMOS SRAMS are discussed and the prediction on several typical orbits are presented.

关键词： proton heavy ions SEU rates Bendel model 65 nm SRAM

Exploring the effect of aggregation-induced emission on the excited state intramolecular proton transfer for a bis-imine derivative by quantum mechanics and our own n-layered integrated molecular orbital and molecular mechanics calculations

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Chinese Physics B 2019年第1期28卷 645-649页

作者：赵慧芳孙朝范刘晓春尹航石英 Institute of Atomic and Molecular Physics Jilin University

We theoretically investigate the excited state intramolecular proton transfer(ESIPT) behavior of the novel fluorophore bis-imine derivative molecule HNP which was designed based on the intersection of 1-(hydrazonomethyl)-naphthalene-2-ol and 1-pyrenecarboxaldehyde. Especially, the density functional theory(DFT) and time-dependent density functional theory(TDDFT) methods for HNP monomer are introduced. Moreover, the "our own n-layered integrated molecular orbital and molecular mechanics"(ONIOM) method(TDDFT:universal force field(UFF)) is used to reveal the aggregation-induced emission(AIE) effect on the ESIPT process for HNP in crystal. Our results confirm that the ESIPT process happens upon the photoexcitation for the HNP monomer and HNP in crystal, which is distinctly monitored by the optimized geometric structures and the potential energy curves. In addition, the results of potential energy curves reveal that the ESIPT process in HNP will be promoted by the AIE effect. Furthermore, the highest occupied molecular orbital(HOMO) and lowest unoccupied molecular orbital(LUMO) for the HNP monomer and HNP in crystal have been calculated. The calculation demonstrates that the electron density decrease of proton donor caused by excitation promotes the ESIPT process. In addition, we find that the variation of atomic dipole moment corrected Hirshfeld population(ADCH) charge for proton acceptor induced by the AIE effect facilitates the ESIPT process. The results will be expected to deepen the understanding of ESIPT dynamics for luminophore under the AIE effect and provide insight into future design of high-efficient AIE compounds.

关键词： time-dependent density functional theory(TDDFT) method excited state intramolecular proton transfer(ESIPT) our own n-layered integrated molecular orbital and molecular mechanics(ONIOM) method potential energy curves atomic dipole moment corrected Hirshfeld population(ADCH) charge

Deep inelastic scattering with proton target in the presence of gluon condensation using holography

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Chinese Physics C 2023年第1期47卷 28-37页

作者： Sara Tahery 王晓鹏陈旭荣 Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China Lanzhou University Lanzhou 730000China University of Chinese Academy of Sciences Bejing 100049China Guangdong Provincial Key Laboratory of Nuclear Science Institute of Quantum MatterSouth China Normal UniversityGuangzhou 510006China

We study the deep inelastic scattering(DIS)of a proton-targeted lepton in the presence of gluon condensation using gauge/gravity duality.We use a modified AdS5background where the modification parameter c corresponds to the gluon condensation in the boundary theory.First,by examining the electromagnetic field,we establish that a non-zero c can increase field magnitude.Our aim is to obtain the acceptable value of c for this scattering.Our method is based on setting the mass of the proton as an eigenvalue of the baryonic state equations of the DIS to find the acceptable value of the parameter c on the other side of the equations.Therefore,in the second step,we calculate wave function equations for the baryonic states where the mass of the proton target requires a value contribution of c as c=0.0120 GeV4.Proceeding with the electromagnetic field and baryonic states,we derive the holographic interaction action related to the amplitude of the scattering.Finally,we compute the corresponding structure functions numerically as functions of x and q,which are Bj?rken variables and the lepton momentum transfers,respectively.Comparing the Jlab Hall C data with our theoretical calculations,our results are acceptable.

关键词： DIS AdS/QCD Gluon condensation proton

Investigation of maximum proton energy for qualified ground based evaluation of single-event effects in SRAM devices

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Nuclear Science and Techniques 2019年第3期30卷 97-104页

作者： Zhan-Gang Zhang Yun Huang Yun-Fei En Zhi-Feng Lei Science and Technology on Reliability Physics and Application of Electronic Component Laboratory China Electronic Product Reliability and Environmental Testing Research Institute

Existing standards show a clear discrepancy in the specification of the maximum proton energy for qualified ground-based evaluation of single-event effects,which can range from 180 to 500 MeV. This work finds that the threshold linear energy transfer of a tested device is a critical parameter for determining the maximum proton energy. The inner mechanisms are further revealed. Highenergy deposition events(>10 MeV) in sensitive volumes are attributed to the interaction between protons and the tungsten vias in the metallization layers.

关键词： proton Single-event effect Threshold LET Monte Carlo simulation

Theoretical study on spherical proton emission

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Science China(Physics,Mechanics & Astronomy) 2009年第10期52卷 1536-1541页

作者： ZHANG HongFei WANG YongJia DONG JianMin LI JunQing School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China Kavli institute for Theoretical Physics China Chinese Academy of SciencesBeijing 100190China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China

The proton radioactivity half-lives of spherical proton emitters are investigated within a generalized liquid drop model(GLDM),including the proximity effects between nuclei in a neck and the mass and charge asymmetry.The penetrability is calculated in the WKB approximation and the assault frequency is estimated by the quantum mechanism method considering the structure of the parent nucleus.The spectroscopic factor is taken into account in half-life calculation,which is obtained by employing the relativistic mean field(RMF) theory.The half-lives within the GLDM are compared with the experimental data and other theoretical values.The results show that the GLDM works quite well for spherical proton emitters when the assault frequency is estimated by the quantum mechanical method and the spectroscopic factor is considered.

关键词： proton emission half-lives spectroscopic factors generalize liquid drop model

Quantifying lateral penumbra advantages of collimated spot-scanning beam for intensity-modulated proton therapy

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Nuclear Science and Techniques 2019年第11期30卷 52-59页

作者： Chun-Bo Liu Yun-Tao Song Hong-Dong Liu Hai-Zhou Xue Han-Sheng Feng University of Science and Technology of China Hefei 230026China Institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China Hefei CAS Ion Medical and Technical Devices Co. LtdHefei 230088China

Intensity-modulated proton therapy(IMPT)is becoming essential for proton therapy and is under rapid development.However,for IMPT,the lateral penumbra of the spot-scanning proton beam is still an urgent issue to be solved.Patient-specific block collimators(PSBCs),which can block unnecessary doses,play a crucial role in passive scattering delivery technology but are rarely used in spot scanning.One objective of this study is to investigate the lateral penumbra variations of intensity-modulated spot scanning with and without a PSBC.For fields with varying degrees of sharpness and at varying depths in a water phantom,the lateral penumbral widths were calculated using a Monte Carlo-based dose engine from RayStation 6.The results suggest that the lateral penumbral widths can be reduced by more than 30%for uniform target volumes,regardless of whether a range-shifter is used,and that the maximum dose beyond the field edges can be reduced significantly.The results of patient cases show that the doses in organs-at-risk near the edge of the target volume decrease if a PSBC is implemented.This study demonstrates that intensity-modulated spot scanning with a PSBC can effectively reduce the lateral penumbra and block unnecessary doses and is therefore promising for clinical applications in spot-scanning proton therapy.

关键词： Lateral penumbra Patient-specific block collimator Monte Carlo Intensity-modulated proton therapy

Meta-heuristic optimization inspired by proton-electron swarm

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The Journal of China Universities of Posts and Telecommunications 2020年第3期27卷 42-52,72页

作者： Liu Yongli Liu Shen School of Computer Science and Technology Henan Polytechnic UniversityJiaozuo 454000China

While solving unimodal function problems,conventional meta-heuristic algorithms often suffer from low accuracy and slow convergence.Therefore,in this paper,a novel meta-heuristic optimization algorithm,named proton-electron swarm(PES),is proposed based on physical rules.This algorithm simulates the physical phenomena of like-charges repelling each other while opposite charges attracting in protons and electrons,and establishes a mathematical model to realize the optimization process.By balancing the global exploration and local exploitation ability,this algorithm achieves high accuracy and avoids falling into local optimum when solving target problem.In order to evaluate the effectiveness of this algorithm,23 classical benchmark functions were selected for comparative experiments.Experimental results show that,compared with the contrast algorithms,the proposed algorithm cannot only obtain higher accuracy and convergence speed in solving unimodal function problems,but also maintain strong optimization ability in solving multimodal function problems.

关键词： meta-heuristic proton electron swarm

632.8-nm visible region waveguide polarizer fabricated by proton exchange

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Science China Mathematics 1997年第7期40卷 773-778页

作者：冯克诚李凌焦文涛王兆民 Department of Optics Physics Institute of Optics and Fine MechanicsChangchun 130022China Department of Physics Siping Education CollegeSiping 136000China

Optical waveguide polarizer at 632.8 nm was fabricated for the first time using proton exchange Ti:LiNbO3.The setup measuring the characteristic parameters of the polarizer was given.The extinction ratio of the polarizer was theoretically analyzed and calculated by means of physical optics and dispersion theory for waveguide.Various factors affecting the device performance are analyzed.Theoretical calculations are in good agreement with the experimental results.

关键词： proton exchange optics waveguide polarizer polarization extinction ratio dispersion theory for waveguide.