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Chinese Chemical Letters 2022年第4期33卷 2031-2035页

作者： Xiaoqian He Kangbao Zhong Dan Heng zhen Zeng Hao Ni Ruopeng bai yu Lan School of Chemistry and Chemical Engineering Chongqing Key Laboratory of Theoretical and Computational ChemistryChongqing UniversityChongqing 400030China College of Chemistry and Institute of Green Catalysis Zhengzhou UniversityZhengzhou 450001China

The Cu(I)-catalyzed [4 + 1] annulation of vinyl indoles and a carbene precursor is a powerful method for constructing cyclopentaindole derivatives. Density functional theory(DFT) calculations were used to elucidate the mechanism and regioselectivity of this reaction. After Cu-assisted indole C3-alkylation, direct1,5-annulation was favored over the Cu-assisted annulation pathway. Furthermore, the regioselectivity for1,5-annulation was attributed to the generated five-membered-ring product being more stable than the three-membered-ring product from 1,3-annulation, which was the kinetically favored pathway.

关键词： Carbene precursor Regioselectivity DFT calculations Cyclopentaindol C3-alkylation

Mean flow and turbulence structure of open channel flow with suspended vegetation

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Journal of Hydrodynamics 2020年第2期32卷 314-325页

作者： Qian Li yu-hong Zeng yu bai State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan430072China

In combination with a channel bed,suspended vegetationin an open channel can alter flow structure and generate vertically asymmetric *** study investigated the mean flow and turbulence structure of an open channel with suspended vegetation through theoretical analysis and laboratory *** patterns of bionic leaves with different roughness were adopted to imitate suspended vegetation,and three-dimensional velocity field was measured by using an acoustic Doppler *** measured data showed that the vertical profile of streamwise velocity obeys a two-power law and that the maximum velocity at the middle depth is close to the smooth boundary(i.e.,the channel bed in the experiment)under the combined action of vegetation cover and channel *** stress is linearly distributed along the vertical axis,and the vertical profile of turbulence intensity obeys an exponential ***,a two-power law expression was adopted to predict the vertical profile of streamwise *** models for the vertical distribution of shear stress and turbulence intensity were also *** predicted results validated by measurements showed that the different magnitudes of vegetation cover and channel bed boundary roughness exert an obvious impact on flow structure.

关键词： Suspended vegetation streamwise velocity shear stress turbulence intensity boundary roughness

DNA damage in nucleosomes

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Science China Chemistry 2019年第5期62卷 561-570页

作者： Mengtian Ren Jing bai zhen Xi Chuanzheng Zhou State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology College of ChemistryNankai University

Eukaryotic genomic DNA is packed into chromatin, whose fundamental structural unit is the nucleosome. As DNA-histone protein complexes, nucleosomes show different properties toward exogenous and endogenous DNA-damaging agents. This review summarizes nucleosome DNA damage due to different sources, including alkylating agents, radicals, UV radiation and reactive DNA damage intermediates. In most cases, the histone core protects the associated DNA against damage via its structure and/or scavenging of damaging agents. In contrast, histones react with damaged DNA and, in some instances, catalyze DNA damage in the nucleosome. The biological consequence of nucleosome DNA damage and future prospects in this field are briefly discussed.

关键词： DNA damage DNA alkylation DNA-protein cross-link nucleosome radical reactive intermediate

BACKWARD STOCHASTIC VIABILITY AND RELATED PROPERTIES ON Z FOR BSDES WITH APPLICATIONS

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Journal of Systems Science & Complexity 2012年第4期25卷 675-690页

作者： zhen WU Zhiyong yu School of Mathematics Shandong University School of Economics Shandong University

This paper investigates some important properties of Z, the martingale integrant of the backward stochastic differential equations, which is the second process of the solution. These include the backward stochastic viability property, bounded property and the comparison theorem. To explain the theoretical results, the authors apply them to study a financial contingent claim pricing problem. The replication portfolio process can be characterized clearly.

关键词： Backward stochastic differential equations backward stochastic viability property Malliavin calculus portfolio choice.

Enhancing interfacial stability in solid-state lithium batteries with polymer/garnet solid electrolyte and composite cathode framework

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Journal of Energy Chemistry 2021年第1期30卷 210-217,I0007页

作者： Long Chen Xiaoming Qiu Zhiming bai Li-zhen Fan Beijing Advanced Innovation Center for Materials Genome Engineering Beijing Key Laboratory for Advanced Energy Materials and TechnologiesUniversity of Science and Technology BeijingBeijing 100083China Beijing Key Laboratory of Advanced Chemical Energy Storage Technologies and Materials Research Institute of Chemical DefenseBeijing 100191China Shanxi Key Laboratory of New Energy Materials and Devices Taiyuan University of Technology030024China School of Materials Science and Engineering Beihang UniversityBeijing 100191China

The solid-state lithium battery is considered as an ideal next-generation energy storage device owing to its high safety,high energy density and low ***,the poor ionic conductivity of solid electrolyte and low interfacial stability has hindered the application of solid-state lithium ***,a flexible polymer/garnet solid electrolyte is prepared with poly(ethylene oxide),poly(vinylidene fluoride),Li6.75La3 Zr1.75Ta0.25O12,lithium bis(trifluoromethanesulfonyl)imide and oxalate,which exhibits an ionic conductivity of 2.0 ×10^(-4) S cm^(-1) at 55℃,improved mechanical property,wide electrochemical window(4.8 V ***/Li+),enhanced thermal *** acidic OX was introduced to inhibit the alkalinity reactions between Li6.75La3 Zr1.75Ta0.25O12 and poly(vinylidene fluoride).In order to improve the interfacial stability between cathode and electrolyte,an Al2 O3@LiNi0.5Co0.2Mn0.3O2 based composite cathode framework is also fabricated with poly(ethylene oxide) polymer and lithium salt as *** solid-state lithium battery assembled with polymer/garnet solid electrolyte and composite cathode framework demonstrates a high initial discharge capacity of 150.6 mAh g^(-1) and good capacity retention of 86.7% after 80 cycles at 0.2 C and 55℃,which provides a promising choice for achieving the stable electrode/electrolyte interfacial contact in solid-state lithium batteries.

关键词： Li6.75La3Zr1.75Ta0.25O12 Polymer/garnet solid electrolyte Interfacial stability Composite cathode framework Lithium metal batteries

Anti-saturation fault-tolerant adaptive torsional vibration control with fixed-time prescribed performance for rolling mill main drive system

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Journal of Iron and Steel Research International 2024年第3期31卷 660-669页

作者： Shuang Liu Chen Du Cong Zhang zhen-hua bai Key Lab of Industrial Computer Control Engineering of Hebei Province Yanshan UniversityQinhuangdao 066004HebeiChina National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan UniversityQinhuangdao 066004HebeiChina

An anti-saturation fault-tolerant adaptive torsional vibration control method with fixed-time prescribed performance for the rolling mill main drive system(RMMDS)was investigated,which is affected by control input saturation,actuator faults,sensor measurement errors,and parameter ***,we gave a continuously differentiable saturation function to approximate the control input saturation characteristic of the RMMDS,translating the saturation characteristic into the matched uncertainty and unknown time-varying gain in the ***,an RMMDS mathematical model with unmatched uncertainty and unknown time-varying gain was developed,taking into account the presence of control input saturation,actuator faults,sensor measurement errors,and parameter *** on the established mathematical model,an error transformation model of the roll speed tracking was constructed by the equivalent error transformation *** to the error transformation model,a barrier Lyapunov function and a novel adaptive controller were studied to ensure that the roll speed tracking error always evolves inside a fixed-time asymmetric ***,numerical simulations were performed in Matlab/Simulink to verify the effectiveness and superiority of the proposed control method in suppressing the RMMDS torsional vibration.

关键词： Fixed-time prescribed performance Control input saturation Actuator fault Unknown time-varying gain Adaptive control Asymmetric constraint

Luminescence Properties and Crystal Growth of Er/Yb Codoped KGd(WO_4)_2

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Chinese Journal of Structural Chemistry 2005年第8期24卷 879-884页

作者： WANG Yan TU Chao-Yang ZHU Zhao-Jie LI Jian-Fu YOU zhen-yu WU bai-Chang State Key Laboratory of Structural Chemistry Fujian Institute of Research on theStructure of Matter The Chinese Academy of Sciences ChinaFuzhou Fujian 350002

In this paper, the spectral and luminescence properties of a series of KGd（WO4）2 powder samples codoped with different concentrations of Er^3＋ and Yb^3＋ were reported,and the best doping concentrations were found to be lat% Er^3＋ and 10at% Yb^3＋ for attaining the strongest intensity. The Er^3＋/yb^3＋ codoped KGd（WO4）2 crystal with good optical quality was grown by the TSSG method and the growth conditions were presented. The unpolarized absorption and emission spectra of the crystal have been measured. The strong absorption peak is at 980 nm with a FWHM of 65 nm, and the emission peak is at 1536 nm when pumped by 976 rim. The fluorescence lifetime of manifold ^4I13/2 is estimated to be 4.5 ms at room *** of Er, Yb：KGW crystal have shown it to have necessary combination of properties to get an effective generation of - 1.54 μm eye-safe radiation with laser diode pumping.

关键词： Er Yb:KGW crystal luminescence properties,crystal growth optical properties

A Revised Graduated Cylindrical Shell Model and its Application to a Prominence Eruption

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Research in Astronomy and Astrophysics 2023年第12期23卷 63-72页

作者： Qing-Min Zhang zhen-Yong Hou Xian-Yong bai Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryNanjing 210023China yunnan Key Laboratory of the Solar Physics and Space Science Kunming 650216China School of Earth and Space Sciences Peking UniversityBeijing 100871China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Solar Activity and Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China

In this paper,the well-known graduated cylindrical shell(GCS)model is slightly revised by introducing longitudinal and latitudinal deflections of prominences originating from active regions(ARs).Subsequently,it is applied to the three-dimensional(3D)reconstruction of an eruptive prominence in AR 13110,which produced an M1.7 class flare and a fast coronal mass ejection(CME)on 2022 September *** is revealed that the prominence undergoes acceleration from~246 to~708 km s^(-1).Meanwhile,the prominence experiences southward deflection by 15°±1°without longitudinal deflection,suggesting that the prominence erupts *** deflections of the prominence and associated CME are consistent,validating the results of fitting using the revised GCS ***,the true speed of the CME is calculated to be 1637±15 km s^(-1),which is~2.3 times higher than that of *** is indicative of continuing acceleration of the prominence during which flare magnetic reconnection reaches maximum beneath the erupting ***,the reconstruction using the revised GCS model could successfully track a prominence in its early phase of evolution,including acceleration and deflection.

关键词： Sun flares-Sun filaments-prominences-Sun coronal mass ejections(CMEs)

Detection of Phaeocystis globosa using sandwich hybridization integrated with nuclease protection assay(NPA-SH)

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Journal of Environmental Sciences 2008年第12期20卷 1481-1486页

作者： zhen yu Mi Tiezhu yu Zhigang Ocean Univ China Minist Educ Key Lab Marine Chem Theory & Technol Qingdao 266100 Peoples R China Ocean Univ China Minist Educ Key Lab Marine Environm & Ecol Qingdao 266100 Peoples R China

Phaeocystis globosa Scherffel is one of the common harmful algae species in coastal waters of the southeastern *** this study,sandwich hybridization integrated with nuclease protection assay(NPA-SH)was used to qualitatively and quantitatively detect P. *** showed that this method had good applicability and validity in analyzing the samples from laboratory cultures and from *** linear regression equation for *** was obtained,and the lowest detection number of cells was 1.8×104 c...

关键词： harmful algae blooms Phaeocystis globosa Scherffel sandwich hybridization integrated with nuclease protection assay (NPA-SH)

Surveying ionizing radiations in real time using a smartphone

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Nuclear Science and Techniques 2017年第5期28卷 81-85页

作者： Qing-Yang Wei Ru bai zhen-Peng Wang Ru-Tao Yao yu Gu Tian-Tian Dai School of Automation and Electrical Engineering Beijing University of Science and Technology School of Medicine and Biological Sciences University at BuffaloState University of New York Department of Radiation Oncology China-Japan Friendship Hospital

Surveying ionizing radiations of the surrounding with a smartphone provides a low-cost and convenient utility for the general public. We developed a smartphone application(App) that uses the built-in camera with a CMOS sensor and a radiation signal extraction *** a calibration through a series of radiation exposures,the App could display radiation dose rate and cumulative dose in real time without requiring covering the camera lens. A smartphone with this App can be used as a fast survey tool for ionizing radiations.

关键词： Ionizing radiation CMOS sensor Smartphone Real time Detection