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Chinese Journal of Structural Chemistry 2020年第9期39卷 1594-1600,1554页

作者： CHEN Guo-Hua JIANG Ning XIANG hai-Yan du hai-Bo College of Chemical Engineering Sichuan University of Science&EngineeringZigong 643000China

The structure of penicillin sulfoxide is rearranged to cephalosporins by the Morin rearrangement. It is a unit reaction for the preparation of various types of cephalosporins. In order to make better use of the reaction and in view of the shortage of the reaction theory, this study used m062x/6-311++G(d, p) to explore the possible ring-opening reaction of the penicillin sulfoxide. It is found that the isomer of(S)-sulfoxide is a necessary structure. At the same time, the intramolecular hydrogen bonding effect between the side-chain amide proton(-CONH-) and the sulfinyl oxygen(-SO) is the decisive structure factor for the formation of alkenyl in ring-opening reaction, and the best reaction path is S0-> TS2-> IN1 channel. The main effect of acid catalysis is to catalyze the dehydration reaction of sulfenic acid to form sulfur cations for subsequently ring closing reaction.

关键词： penicillin G sulfoxide morin rearrangement reaction mechanism theoretical study cephalosporins

Epigenetic Modifications of mRNA and DNA in Plants

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Molecular Plant 2020年第1期13卷 14-30页

作者： Zhe Liang Adeel Riaz Sadaruddin Chachar Yike Ding hai du Xiaofeng Gu biotechnology Research Institute Chinese Academy of Agricultural SciencesBeijing 100081China Centre for Organismal Studies Heidelberg UniversityHeidelberg 69120Germany Department of Entomology University of California RiversideRiversideCA 92521USA College of Agronomy and Biotechnology Southwest UniversityChongqing 400715China

Advances in the detection and mapping of messenger RNA(mRNA)N^6-methyladenosine(m 6A)and 5-methylcytosine(m 5C),and DNA N^6-methyldeoxyadenosine(6mA)redefined our understanding of these modifications as additional tiers of epigenetic *** plants,the most prevalent internal mRNA modifications,m^6A and m^5C,play crucial and dynamic roles in many processes,including embryo development,stem cell fate determination,trichome branching,leaf morphogenesis,floral transition,stress responses,fruit ripening,and root *** newly identified and widespread epigenetic marker 6mA DNA methylation is associated with gene expression,plant development,and stress ***,we review the latest research progress on mRNA and DNA epigenetic modifications,including the detection,dynamics,distribution,functions,regulatory proteins,and evolution,with a focus on m^6A,m^5C,and *** also provide some perspectives on future research of the newly identified and unknown epigenetic modifications of mRNA and DNA in plants.

关键词： RNA modification m^6A m^5C DNA methylation 6mA epigenetics

Attacking a high-dimensional quantum key distribution system with wavelength-dependent beam splitter

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Chinese Physics B 2019年第9期28卷 87-92页

作者： Ge-hai du Hong-Wei Li Yang Wang Wan-Su Bao Henan Key Laboratory of Quantum Information and Cryptography PLA SSF IEUZhengzhou 450001China Synergetic Innovation Center of Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China

The unconditional security of quantum key distribution(QKD) can be guaranteed by the nature of quantum *** with the traditional two-dimensional BB84 QKD protocol, high-dimensional quantum key distribution(HDQKD) can be applied to generate much more secret ***, practical imperfections in realistic systems can be exploited by the third party to eavesdrop the secret *** practical beam splitter has a correlation with wavelength,where different wavelengths have different coupling *** this property, we propose a wavelength-dependent attack towards time-bin high-dimensional QKD *** is more, we demonstrate that this attacking protocol can be applied to arbitrary d-dimensional QKD system, and higher-dimensional QKD system is more vulnerable to this attacking strategy.

关键词： high-dimensional quantum key distribution beam splitter wavelength attack

Vortex dynamics over an airfoil controlled by a nanosecond pulse discharge plasma actuator at low wind speed

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Plasma Science and Technology 2019年第12期21卷 85-96页

作者： hai du LeiWANG Wenjie KONG Zhiwei SHI Keming CHENG Zheng LI School of Energy and Power Engineering Xihua UniversityChengdu 610039People's Republic of China Key Laboratory of Fluid and Power Machinery Ministry of EducationXihua UniversityChengdu 610039People's Republic of China College of Aerospace Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016People's Republic of China

The vortex dynamics of flow over an airfoil controlled by a nanosecond pulse dielectric-barrierdischarge(NS-DBD) actuator is studied at a Reynolds number of 1?×?10~5 through wind tunnel experiments and numerical simulation. The numerical method is validated through comparison of the simulated and measured results regarding the effect of the discharge of an NS-DBD actuator placed on a flat plate. The simulated results show that vorticity is mainly induced by the baroclinic torque after plasma discharge, i.e. the term(■) in the equation of vorticity evolution. Both experimental and simulated results demonstrate that after the discharge of the NS-DBD actuator a series of vortices are developed in the shear layer and pull the high-moment fluid down to the wall, enhancing the mixing of internal and external flows.

关键词： plasma actuator flow control Joule heating vortex

Phase order in one-dimensional piecewise linear discontinuous map

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Chinese Physics B 2018年第10期27卷 240-244页

作者： Ru-hai du Sheng-Jun Wang Tao Jin Shi-Xian Qu Institute of Theoretical ＆ Computational Physics Shaanxi Normal UniversityXi＇an 710119China School of Physics and Information Technology Shaanxi Normal UniversityXi＇an 710119China

The phase order in a one-dimensional（1 D） piecewise linear discontinuous map is investigated. The striking feature is that the phase order may be ordered or disordered in multi-band chaotic regimes, in contrast to the ordered phase in continuous systems. We carried out an analysis to illuminate the underlying mechanism for the emergence of the disordered phase in multi-band chaotic regimes, and proved that the phase order is sensitive to the density distribution of the trajectories of the attractors. The scaling behavior of the net direction phase at a transition point is observed. The analytical proof of this scaling relation is obtained. Both the numerical and analytical results show that the exponent is 1, which is controlled by the feature of the map independent on whether the system is continuous or discontinuous. It extends the universality of the scaling behavior to systems with discontinuity. The result in this work is important to understanding the property of chaotic motion in discontinuous systems.

关键词： chaos piecewise discontinuous map direction phase

Analysis of flow separation control using nanosecond-pulse discharge plasma actuators on a flying wing

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Plasma Science and Technology 2018年第11期20卷 116-125页

作者： Zheng LI Zhiwei SHI hai du Qijie SUN Chenyao WEI Xi GENG College of Aerospace Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016 People＇s Republic of China The Key Laboratory of Fluid and Power Machinery Xihua UniversityChengdu 610039People＇s Republic of China

Dielectric barrier discharge （DBD） plasma is one of most promising flow control method for its several advantages. The present work investigates the control authority of nanosecond pulse DBD plasma actuators on a flying wing model＇s aerodynamic characteristics. The aerodynamic forces and moments are studied by means of experiment and numerical simulation. The numerical simulation results are in good agreement with experiment results. Both results indicate that the NS-DBD plasma actuators have negligible effect on aerodynamic forces and moment at the angles of attack smaller than 16-. However, significant changes can be achieved with actuation when the model＇s angle of attack is larger than 16° where the flow separation occurs. The spatial flow field structure results from numerical simulation suggest that the volumetric heat produced by NS-DBD plasma actuator changes the local temperature and density and induces several vortex structures, which strengthen the mixing of the shear layer with the main flow and delay separation or even reattach the separated flow.

关键词： nanosecond dielectric barrier discharge flying wing aircraft flow separation control

High Performance Humidity Sensor Based on Electrospun Zr_(0.9)Mg_(0.1)O_(2−δ) Nanofibers

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Chinese Physics Letters 2012年第11期29卷 27-30页

作者： SU Mei-Ying WANG Jing YAO Peng-Jun du hai-Ying School of Electronic Science and Technology Dalian University of TechnologyDalian 116023 Institute of Microelectronics of Chinese Academy SciencesBeijing 100029 School of Educational Technology Shenyang Normal UniversityShenyang 110034 Department of Electromechanical Engineering&Information Dalian Nationalities UniversityDalian 116600

Zr_(0.9)Mg_(0.1)O_(2−δ) nanofibers and ZrO_(2) nanofibers are synthesized using electrospinning and the calcination *** nanofibers are characterized using x-ray diffraction(XRD),a field emission scanning electron microscope(FE-SEM),and a Brunauer–Emmett–Teller(BET)surface *** humidity sensing properties of Zr_(0.9)Mg_(0.1)O_(2−δ) nanofiber sensors are analyzed and compared with those of ZrO_(2) nanofiber *** Zr_(0.9)Mg_(0.1)O_(2−δ) nanofiber humidity sensors exhibit a broader humidity range of 11–97%relative humidity(RH),good linearity,small humidity hysteresis,and rapid response and recovery *** complex impedance plots of the Zr_(0.9)Mg_(0.1)O_(2−δ) sensor at different RHs are drawn,and the humidity sensing mechanism is discussed via an equivalent circuit.

关键词： fibers humidity fiber

Application of Geometric Midline Yield Criterion for Strip Drawing

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Journal of Iron and Steel Research International 2009年第6期16卷 13-16页

作者： WANG Gen-ji du hai-jun ZHAO De-wen LIU Xiang-hua WANG Guo-dong State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 Liaoning China

A new linear yield criterion expressed by the geometric midline of error triangle between Tresca and Twin shear stress yield loci on the π-plane in haigh-Westergaard space was introduced. The criterion was written in terms of the values of principal stress deviator and called GM yield criterion for short. Together with a Cartesian coordinate velocity field instead of the Avitzur＇s, the GM criterion was used to obtain an analytical solution for strip drawing. With a working example of the strip drawing through wedge-shaped die, the results of relative drawing stress calculated by the GM criterion were compared with those calculated by Mises＇ criterion from Avitzur formula. It indicated that the calculated results according to analytical solution were in good agreement with the numerical solution obtained from Avitzur formula.

关键词： GM yield criterion strip drawing analytical solution

Immunological Responses to the Combination of EBNA1 and LMP2 in Mice

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Biomedical and Environmental Sciences 2019年第5期32卷 380-382页

作者： du hai Jun TONG Yan Yan WANG Zhan ZHANG Li Xia ZENG Yi State Key Laboratory for Infectious Disease Prevention and Control National Institute of Viral Disease Control and PreventionChinese Center for Disease Control and PreventionBeijing 102206China College of Life Science and Bioengineering Beijing University of TechnologyBeijing 100124China

Epstein-Barr virus (EBV) infection is closely associated with nasopharyngeal carcinoma (NPC)and considered one of the major risk factors[1]. A limited number of viral proteins, such as latent membrane proteins (LMP1, LMP2) and EB nuclear antigen1 (EBNA1), are expressed in NPC cells[2].Recognition epitopes for CD8+and CD4+T cells were included in the LMP2 antigen and EBNA1 C-terminal region (amino acid No. 380-641), respectively[3,4].Both CD4+and CD8+memory T-cell responses were efficiently reactivated by EBNA1 and LMP2[5;6].

关键词： Immunological Responses EBNA1 LMP2

Preparation and Characterization of Cu_3V_2O_7(OH)_2·2H_2O Hollow Spheres from Na_2V_6O_16·3H_2O Nanobelts

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Chemical Research in Chinese Universities 2009年第2期25卷 132-137页

作者： YANG Fang JI Tian-hao du hai-yan SUN ha-yue YANG Qing-lin GE Guang-lu College of Chemical and Environmental Engineering Beo＇ing Technology and Business UniversityBeijing 100037 P. R. China Department of Applied Chemistry Beijing University of Aeronautics and Astronautics Beijing 100083 P R. China National Center for Nanoscinece and Technology Beijing 100190 P. R. China

Monoclinic Cu3V2O7（OH）2·2H2O（copper polyvanadate） hollow spheres were prepared with Na2V6O16·3H2O nanobelts as V-precursor by hydrothermal method. The purity and structure of the products were characterized by X-ray powder diffraction（XRD）, Fourier transform infrared（FTIR） spectroscopy, Raman spectroscopy, thermogravimetric analysis（TGA） and X-ray photoelecton spectroscopy（XPS）. The morphology and size were observed by scanning electron microscopy（SEM）. We found that the Kagomé staircase-structural copper polyvanadate hollow spheres with an average diameter of 7 μm could be easily synthesized via the reaction of Na2V6O16·3H2O nanobelts with sufficient copper sulfate. The dielectric property of the copper polyvanadate demonstrates that dielectric loss hardly changes when the frequency of applied electric field is higher than 100 kHz. The formation process of the hollow spheres is discussed in detail by the observation of a series of products prepared for different reaction time.

关键词： Hydrothermal synthesis Nanobelt Oxide Hollow sphere Monoclinic copper polyvanadate