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Chinese Physics Letters 2024年第5期41卷 17-22页

作者：金无维王春成赵晓戈杨译章任殿相刘泽槿李孝开罗嗣佐丁大军 institute of Atomic and molecular Physics Jilin UniversityChangchun 130012China Jilin Provincial Key Laboratory of applied Atomic and molecular Spectroscopy Jilin UniversityChangchun 130012China

Ethylene, the simplest model of a carbon-carbon double bond system, is pivotal in numerous chemical and biological processes. By employing intense infrared laser pump-probe techniques alongside coincidence measurements, we investigate the ultrafast non-adiabatic dynamics involved in the breakage of carbon-carbon double bonds and hydrogen elimination in dissociation of ethylene. Our study entails analyzing the dynamic kinetic energy release spectra to assess three bond-breaking scenarios, movements of nuclei, and structural changes around the carbon atoms. This allows us to evaluate the relaxation dynamics and characteristics of various dissociative states. Notably, we observe a significant rise in the yield of fragments resulting from C–H bond breakage with the delay time extended, suggesting non-adiabatic coupling through conical intersections from C–C bond breakage as a probable cause.

关键词： pump Femto adiabatic

Common stemness regulators of embryonic and cancer stem cells

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World Journal of Stem Cells 2015年第9期7卷 1150-1184页

作者： Christiana Hadjimichael Konstantina Chanoumidou Natalia Papadopoulou Panagiota Arampatzi Joseph Papamatheakis Androniki Kretsovali Department of biology University of Crete institute of molecular biology and Biote- chnology Foundation for Research and Technology Hellas(FORTH) Department of molecular biology and Genetics Democritus University of Thrace

Pluripotency of embryonic stem cells(ESCs) and induced pluripotent stem cells is regulated by a well characterized gene transcription circuitry. The circuitry is assembled by ESC specific transcription factors, signal trans-ducing molecules and epigenetic regulators. Growing understanding of stem-like cells, albeit of more complex phenotypes, present in tumors(cancer stem cells), provides a common conceptual and research frame-work for basic and applied stem cell biology. In this review, we highlight current results on biomarkers, gene signatures, signaling pathways and epigenetic regulators that are common in embryonic and cancer stem cells. We discuss their role in determining the cell phenotype and finally, their potential use to design next generation biological and pharmaceutical approaches for regenerative medicine and cancer therapies.

关键词： Embryonic stem cells Cancer stem cells Pluripotenc

Effects of 5f-elements on electronic structures and spectroscopic properties of gold superatom model

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Chinese Physics B 2016年第8期25卷 1-9页

作者：高阳王志刚 institute of Atomic and molecular Physics Jilin University Changchun 130012 China Jilin Provincial Key Laboratory of applied Atomic and molecular Spectroscopy (Jilin University) Changchun 130012 China

5f-elements encaged in a gold superatomic cluster are capable of giving rise to unique optical properties due to their hyperactive valence electrons and great radial components of 5f/6d orbitals. Herein, we review our first-principles studies on electronic structures and spectroscopic properties of a series of actinide-embedded gold superatomic clusters with different dimensions. The three-dimensional（3D） and two-dimensional（2D） superatom clusters possess the 18-electron configuration of 1S21P61D10 and 10-electron configuration of 1S21P41D4, respectively. Importantly, their electronic absorption spectra can also be effectively explained by the superatom orbitals. Specifically, the charge transfer（CT） transitions involved in surface-enhance Raman spectroscopy（SERS） spectra for 3D and 2D structures are both from the filled 1D orbitals, providing the enhancement factors of the order of ～ 10^4 at 488 nm and ～ 10^5 at 456 nm, respectively. This work implies that the superatomic orbital transitions involved in 5f-elements can not only lead to a remarkable spectroscopic performance, but also a new direction for optical design in the future.

关键词： 5f-electrons ds-electrons superatom first-principles

Dynamic stabilization of atomic ionization in a high-frequency laser field with different initial angular momenta

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Chinese Physics B 2022年第10期31卷 82-87页

作者： Di-Yu Zhang Yue Qiao Wen-Di Lan Jun Wang Fu-Ming Guo Yu-Jun Yang Da-Jun Ding institute of Atomic and molecular Physics Jilin UniversityChangchun 130012China Jilin Provincial Key Laboratory of applied Atomic and molecular Spectroscopy(Jilin University) Changchun 130012China

We investigated the ionization of an atom with different orbital angular momenta in a high-frequency laser field by solving the time-dependent Schr¨odinger *** results showed that the ionization stabilization features changed with the relative direction between the angular momentum of the initial state and the vector field of the laser *** ionization mechanism of the atom irradiated by a high frequency was explained by calculating the transition matrix and evolution of the time-dependent wave *** study can provide comprehensive understanding to improve atomic nonadiabatic ionization.

关键词： stabilization of atomic ionization atomic initial states

Effect of sample temperature on femtosecond laser ablation of copper

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Chinese Physics B 2024年第2期33卷 377-385页

作者：党伟杰陈雨桐陈安民金明星 institute of Atomic and molecular Physics Jilin UniversityChangchun 130012China Jilin Provincial Key Laboratory of applied Atomic and molecular Spectroscopy Jilin UniversityChangchun 130012China

We conduct an experimental study supported by theoretical analysis of single laser ablating copper to investigate the interactions between laser and material at different sample temperatures,and predict the changes of ablation morphology and lattice *** investigating the effect of sample temperature on femtosecond laser processing,we conduct experiments on and simulate the thermal behavior of femtosecond laser irradiating copper by using a two-temperature *** simulation results show that both electron peak temperature and the relaxation time needed to reach equilibrium increase as initial sample temperature *** the sample temperature rises from 300 K to 600 K,the maximum lattice temperature of the copper surface increases by about 6500 K under femtosecond laser irradiation,and the ablation depth increases by 20%.The simulated ablation depths follow the same general trend as the experimental *** work provides some theoretical basis and technical support for developing femtosecond laser processing in the field of metal materials.

关键词： femtosecond laser two-temperature model sample temperature ablation depth

Interference effect of photoionization of hydrogen atoms by ultra-short and ultra-fast high-frequency chirped pulses

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Chinese Physics B 2019年第8期28卷 112-118页

作者： Ningyue Wang Aihua Liu institute of Atomic and molecular Physics Jilin UniversityChangchun 30012China Jilin Provincial Key Laboratory of applied Atomic and molecular Spectroscopy Jilin UniversityChangchun 130012China

The photoionization of a hydrogen atom from its ground state with ultra-fast chirped pulses is investigated by numerically solving the time-dependent Schrodinger equation within length,velocity,and Kramers-Henneberger *** results for all gauges for chirp-free pulses agree with the prediction of dynamic interference for ground state hydrogen atoms predicted recently by Jiang and Burgdorfer[*** 26,19921(2018)].In addition,we investigated photoelectron spectra of hydrogen atoms by chirped laser pulses,and showed that dynamic interference effect will be weaken for pulses with increasing linear *** numerical results can be understood and discussed in terms of an interplay of photoelectron wavepackets from first and second halves of laser enevelop,including the ac Stark energy level shift of the photoelectron final state and atomic stabilization effect at ultra-high intensities.

关键词： dynamic interference super-intense laser chirped pulses

Amplitude and rotation of the ellipticity of harmonics from a linearly polarized laser field

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Chinese Physics B 2022年第10期31卷 88-95页

作者： Ping Li Na Gao Rui-Xian Yu Jun Wang Su-Yu Li Fu-Ming Guo Yu-Jun Yang institute of Atomic and molecular Physics Jilin UniversityChangchun 130012China Jilin Provincial Key Laboratory of applied Atomic and molecular Spectroscopy(Jilin University) Changchun 130012China

We simulate the dynamic response of H^(+)_(2) in a linearly polarized laser field by numerically solving the time-dependent Schr?dinger *** elliptically polarized high-order harmonics generated by H^(+)_(2)irradiated by the linearly polarized laser field are systematically *** result shows that the amplitude and rotation of the ellipticity of harmonics are affected by the alignment angle and internuclear distance of the *** the change in forces acted on the ionized electrons and the trajectories of the electrons,the phenomena are found to be due to the change in the direction of the total Coulomb forces from the two nuclei felt by the recollided ionized electrons in the direction perpendicular to the laser polarization *** on the influence law,we can select the harmonics with a specific frequency band under different alignment angles and then synthesize the isolated attosecond pulses with different rotations,which can be continuously converted from right-handed circular polarization,linear polarization,and left-handed circular polarization by changing the alignment *** study provides a new possible approach to the real-time detection of molecular states by using attosecond pulses and obtaining more optimized harmonics with molecular properties.

关键词： high-order harmonic ellipticity rotation attosecond pulses

Improved degradation of azo dyes by lignin peroxidase following mutagenesis at two sites near the catalytic pocket and the application of peroxidase-coated yeast cell walls

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Frontiers of Environmental Science & Engineering 2021年第2期 14-23页

作者： Karla Ili? ?ur?i? Raluca Ostafe Olivera Prodanovi? Aleksandra ?ur?evi? ?elma? Nikolina Popovi? Rainer Fischer Stefan Schillberg Radivoje Prodanovi? University of Belgrade-Faculty of Chemistry molecular Evolution Protein Engineering and Production facility (MEPEP) Purdue University institute of molecular Biotechnology RWTH Aachen University institute for Multidisciplinary Research Departments of Biological Sciences and Chemistry Purdue University fraunhofer institute for molecular biology and applied ecology IME

The enzymatic degradation of azo dyes is a promising alternative to ineffective chemical and physical remediation *** peroxidase(LiP) from Phanerochaete chrysosporium is a hemecontaining lignin-degrading oxidoreductase that catalyzes the peroxide-dependent oxidation of diverse molecules,including industrial *** enzyme is therefore ideal as a starting point for protein ***,we subj ected two positions(165 and 264) in the environment of the catalytic Trp171 residue to saturation mutagenesis,and the resulting library of 10～4 independent clones was expressed on the surface of yeast *** yeast display library was used for the selection of variants with the ability to break down structurally-distinct azo dyes more *** identified mutants with up to 10-fold greater affinity than wild-type LiP for three diverse azo dyes(Evans blue,amido black 10 B and Guinea green) and up to 13-fold higher catalytic ***,cell wall fragments displaying mutant LiP enzymes were prepared by toluene-induced cell lysis,achieving significant increases in both enzyme activity and stability compared to a whole-cell *** cell wall fragments retained their initial dye degradation activity after 10 reaction cycles each lasting 8 *** best-performing mutants removed up to 2.5-fold more of each dye than the wild-type LiP in multiple reaction cycles.

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Orientations of special water dipoles that accelerate water molecules exiting from carbon nanotube

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applied Mathematics and Mechanics(English Edition) 2011年第9期32卷 1101-1108页

作者：亓文鹏涂育松万荣正方海平 Department of Physics Shandong University Shanghai institute of applied Physics Chinese Academy of Scineces institute of Systems biology Shanghai University

One-dimensional ordered water molecules entering and exiting from a carbon nanotube with an appropriate radius are studied with molecular dynamics *** can be found that a water molecule near the nanotube end is more likely to be expelled from the nanotube if its dipole is almost perpendicular to the nanotube *** key to this observation is that those water molecules are closer to the wall of the nanotube away from the equilibrium position of the Lennar-Jones （LJ） ***,the interaction energy for those water molecules is relatively *** are two particular structures of the perpendicular water molecule depending on the dipole direction of the adjacent water molecule in the *** the probabilities of these structures are quite small,their contributions to the net flux across the nanotube end are approximately equal to the predominant *** present findings further show the possibility of controlling the water flow by regulating the dipole directions of the water molecules inside the nanochannels.

关键词： water carbon nanotube single-file water chain Lennard-Jones (LJ) interaction

Concentrations and Sources of Polycyclic Aromatic Hydrocarbons in Topsoil of Benxi City, Northeast China

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Chinese Geographical Science 2011年第2期21卷 185-194页

作者： LI Fengmei GUO Shuhai WU Bo YE Hanfeng institute of applied ecology Chinese Academy of Sciences Shenyang 110016 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

Polycyclic aromatic hydrocarbons (PAHs) contamination of topsoil in Benxi City, Northeast China was investigated in this study, and sampling sites were located in industrial area and residential area. Results demonstrate that there is high variability in the total PAHs concentrations, ranging from 783.00 ng/g to 729 076.29 ng/g dry weight in the topsoil of Benxi City and the pollution in industrial area is the most serious. The results also present that higher molecular weight PAHs (4–6 rings) contribute substantially (79.03%) to the overall content of PAHs. The PAHs sources were determined with factor analysis by nonnegative constraints, and the results show that PAHs originating from traffic tunnel, power plant, coke oven and residential emission sources, account for 27.10%, 40.81%, 20.11% and 11.98%, respectively, of the total. The PAHs pollution is the most serious around Benxi Iron and Steel Group Corporation, and the PAHs mainly originate from coke oven and traffic tunnel, with the average contribution rate of 57.40% and 42.60%, respectively. The source apportionment results are basically consistent with the industry distribution, and the geographical and climatic characteristics of the study area.

关键词： polycyclic aromatic hydrocarbons concentration characteristics source apportionment factor analysis