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Organic Chemistry Frontiers 2022年第4期9卷 1056-1064页

作者： Hong-Jing Long Lei Zhang Bing Lian de-cai fang College of Chemistry Beijing Normal UniversityBeijing100875P.R.China Tianjin Engineering Technology Center of Chemical Wastewater Source Reduction and Recycling School of ScienceTianjin Chengjian UniversityTianjin300384P.R.China

We report a density functional theory study on the ruthenium-catalyzed decarbonylative annulation of an alkyne with a six-membered hydroxychromone via C–H/C–C *** plausible catalytic cycles involve O–H deprotonation,C–H activation,alkyne insertion and formal[3+2]cycloaddition,oxidative insertion and decarbonylation,reductive annulation and the recovery of the catalyst.

关键词： catalyst activation membered

THEORETICAL　STUDIES　ON　THE　CYCLOADDITION　REACTION　OF　FLUOROKETENE　WITH　ETHYLIdeNIMINE

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Chinese Chemical Letters 1995年第4期6卷 311-314页

作者： Zhen Feng XU de cai fang Xiao Yuan FU(department of Chemistry, Beijing Normal University, Beijing, 100875) Beijing Normal Univ Dept Chem Beijing 100875 Peoples R China

The stereospecific rule of the cycloaddition reaction of ketene and imine has been treated theoretically in this Paper. By comparing the barrier heights, it can be seen that for trans imine the reaction will give cis ... 详细信息

关键词：颍

Dual-functional MnS_(2)/MnO_(2) heterostructure catalyst for efficient acidic hydrogen evolution reaction and assisted degradation of organic wastewater

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Journal of Energy Chemistry 2023年第12期87卷 215-224,I0007页

作者： Wen Kang Zhao Zi Qiang Ma Jia Yu Zheng Chang Bao Han Kai Ling Zhou Ming Yang Hao de cai fang Yi Xia Hui Yan The Key Laboratory of Advanced Functional Materials Ministry of Education of ChinaFaculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China

The design and synthesis of non-precious metal dual-functional electrocatalysts through the modulation of electronic structure are important for the development of renewable hydrogen ***,MnS_(2)/MnO_(2)-CC heterostructure dual-functional catalysts with ultrathin nanosheets were prepared by a twostep electrodeposition method for efficient acidic hydrogen evolution reaction(HER) and degradation of organic wastewater(such as methylene blue(MB)).The electronic structure of Mn atoms at the MnS_(2)/MnO_(2)-CC heterostructure interface is reconfigured under the joint action of S and O *** calculations show that the Mn d-band electron distribution in MnS_(2)/MnO_(2)-CC catalyst has higher occupied states near the Fermi level compared to the MnO_(2) and MnS_(2) catalysts,which indicates that MnS_(2)/MnO_(2)-CC catalyst has better electron transfer capability and catalytic *** MnS_(2)/MnO_(2)-CC catalysts require overpotential of only 66 and 116 mV to reach current density of 10 and 100 mA cm^(-2)in MB/H_(2)SO_(4) *** MnS_(2)/MnO_(2)-CC catalyst also has a low Tafel slope(26.72 mV dec^(-1)) and excellent stability(the performance does not decay after 20 h of testing).In addition,the MB removal efficiency of the MnS_(2)/MnO_(2)-CC catalyst with a better kinetic rate(0.0226) can reach 97.76%,which is much higher than that of the MnO_(x)-CC catalyst(72.10%).This strategy provides a new way to develop efficient and stable non-precious metal dual-functional electrocatalysts for HER and organic wastewater degradation.

关键词： Hydrogen evolution reaction(HER) Dual-functional electrocatalysts Heterostructure Catalytic activity degradation of organic wastewater

Nonuniform sampled angular spectrum method by using trigonometric interpolation

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Chinese Physics B 2018年第9期27卷 282-286页

作者： Qiu-Hu Cheng Shi-Yu Wang Meng-Yao Wu Zhen Guo de-fang cai Bing-Bin Li School of Physics mid Optoclectronic Engineering.Xidian University XIan 710071.China

The angular spectrum method（ASM） is a popular numerical approach for scalar diffraction calculations. However,traditional ASM has an inherent problem in that nonuniform sampling is precluded. In an attempt to address this limitation,an improved trigonometric interpolation ASM（TIASM） is proposed, in which the fast Fourier transform（FFT） is replaced by a trigonometric interpolation. The results show that TIASM is more suitable to situations in which the source field has a simple and strong frequency contrast, irrespective of whether the original phase distribution is a plane wave or a Fresnel zone plate phase distribution.

关键词： wave optics diffraction Fourier optics diffraction efficiency

AB INITIO STUDIES ON THE REACTION MECHANISH OF CYCLOADDITION OF KETENE AND FORMALdeHYde

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Chinese Chemical Letters 1992年第5期3卷 367-368页

作者： de cai fang Xiao Yuan FUChemistry department,Beijing Normal University,Boijing 100875

The cycloaddition reaction of ketene and formaldehyde,lesding to 2- oxetanone,has been studied theoretically by means of RHF/*** reaction is believed to be nonsynchronous but concerted,taking place through a twisted four membered ring transition *** types of frontier orbital interactions are involved in this *** activation barrier is calculated to be 123.1KJ/mol (MP2/3-21G result).

关键词： AB INITIO STUDIES ON THE REACTION MECHANISH OF CYCLOADDITION OF KETENE AND FORMALdeHYde PI

High-power and high optical conversion efficiency diode-end-pumped laser with multi-segmented Nd：YAG/Nd：YVO-4

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Chinese Physics B 2018年第9期27卷 306-310页

作者： Meng-Yao Wu Peng-Fei Qu Shi-Yu Wang SEl Zhen Guo de-fang cai Bing-Bin Li School of Physics and Optoelectonic Engineering Xidian University Xi' an 710071 China Xi'an Institute of Electro-Mechanical Information Technology Research Xi'an 710065 China

A novel flat-flat resonator consisting of two crystals（Nd：YAG ＋ Nd：YVO4） is established for power scaling in a diode-end-pumped solid-state laser. We systematically compare laser characteristics between multi-segmented（Nd：YAG ＋ Nd：YVO4） and conventional composite（Nd：YAG ＋ Nd：YAG） crystals to demonstrate the feasibility of spectral line matching for output power scale-up in end-pumped lasers. A maximum continuous-wave output power of 79.2 W is reported at 1064 nm, with Mx2= 4.82, My2= 5.48, and a pumping power of 136 W in the multi-segmented crystals（Nd：YAG ＋ Nd：YVO4）. Compared to conventional composite crystals（Nd：YAG ＋ Nd：YAG）, the optical-optical conversion efficiency of multi-segmented crystals（Nd：YAG ＋ Nd：YVO4） from 808 nm to 1064 nm is enhanced from 30% to 58.8%,while the laser output sensitivity as affected by the diode-laser temperature is reduced from 55% to 9%.

关键词： diode-pumped solid-state laser multi-segmented crystals(Nd:YAG + Nd:YVO4) spectral line matching diode-laser temperature

AB INITIO STUDIES ON THE INTERACTION BETWEEN CH_3OH AND H_2CO

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Chinese Chemical Letters 1990年第1期1卷 17-18页

作者： de cai fang Xiao Yuan FU Chemistry department,Beijing Normal University,Beijing 100875

The interaction between CH_3OH and H_2CO has been studied by ab initio method(6-311G basis set).It has been found that there are two possible complexes:(Ⅰ)H-bond Brnsted complex CH_3OH...OCH_2(Ⅱ)Donor scceptor Lewis complex CH_3OH...CH_***/6-311G stabilization energies for complex(Ⅰ)and complex(Ⅱ)are 25.1 and 17.1 kJ/mol respectively.

关键词： OH ES AB INITIO STUDIES ON THE INTERACTION BETWEEN CH3OH AND H2CO CH CO

MCSCF STUDIES ON THE IRC AND REACTION RATE CONSTANTS FOR THE deHYDROGENATION REACTION OF VINYL RADICAL

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Chinese Chemical Letters 1993年第5期4卷 421-422页

作者： de cai fang Xiao Yuan FU. Chemistry department, Beijing Normal University, Beijing 100875

The transition state(TS) and Intrinsic Reaction Coordinate (IRC) for the titled reaction were traced by means of MCSCF/6-31G (210 configurations). The reaction activation energy of this reaction is 140.2KJ/mol. The re... 详细信息

关键词： IRC MCSCF STUDIES ON THE IRC AND REACTION RATE CONSTANTS FOR THE deHYDROGENATION REACTION OF VINYL RADICAL

Structural characteristics and drivers of greenhouse gas emissions at county-level and long-time scales:A case study of the Anji County,China

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Journal of Environmental Sciences 2024年第6期140卷 319-330页

作者： Zhouxiang cai Liting Hu Di Chen Ying Zhang Xuekun fang College of Environmental&Resource Sciences Zhejiang UniversityHangzhou 310058China Center for Global Change Science Massachusetts Institute of TechnologyCambridgeMA 02139United States Anji Meteorological Bureau Anji 313300China

To achieve carbon neutrality,the Chinese government needs to gain a comprehensive understanding of the sources and drivers of greenhouse gas(GHG)emissions,particularly at the county *** County in eastern China is a typical example of an industrial transformation from quarrying to a low-carbon *** study analyzed the decoupling types and structural characteristics of GHG emissions and the driving factors of carbon dioxide(CO_(2))emissions in the Anji from 2006 to 2019,and explored the differences between countylevel and provincial-level or city-level *** was observed that energy-related activities are the main source of GHG emissions in Anji and that economic development is the driving factor behind the increasing CO_(2)***,industrial transformation and upgradation coupled with the alternative use of clean energy limit the growth of GHG *** study details the GHG emissions of county during the industrial transformation stage and provides corresponding policy recommendations for county governments.

关键词： County GHG emissions decoupling Driving factors Policy recommendations

Life forms affect beta-diversity patterns of larch forests in China

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Plant Diversity 2024年第1期46卷 49-58页

作者： Wenjing fang Qiong cai Chengjun Ji Jiangling Zhu Zhiyao Tang Jingyun fang School of Ecology and Environmental Science Yunnan UniversityKunming 650091China department of Ecology College of Urban and Environmental Sciencesand Key Laboratory for Earth Surface Processes of the Ministry of EducationPeking UniversityBeijing 100871China

Beta-diversity reflects the spatial changes in community species composition which helps to understand how communities are assembled and biodiversity is formed and maintained. Larch(Larix) forests, which are coniferous forests widely distributed in the mountainous and plateau areas in North and Southwest China, are critical for maintaining the environmental conditions and species diversity. Few studies of larch forests have examined the beta-diversity and its constituent components(species turnover and nestedness-resultant components). Here, we used 483 larch forest plots to determine the total betadiversity and its components in different life forms(i.e., tree, shrub, and herb) of larch forests in China and to evaluate the main drivers that underlie this beta-diversity. We found that total betadiversity of larch forests was mainly dependent on the species turnover component. In all life forms,total beta-diversity and the species turnover component increased with increasing geographic, elevational, current climatic, and paleoclimatic distances. In contrast, the nestedness-resultant component decreased across these same distances. Geographic and environmental factors explained 20%-25% of total beta-diversity, 18%-27% of species turnover component, and 4%-16% of nestedness-resultant component. Larch forest types significantly affected total beta-diversity and species turnover component. Taken together, our results indicate that life forms affect beta-diversity patterns of larch forests in China, and that beta-diversity is driven by both niche differentiation and dispersal limitation. Our findings help to greatly understand the mechanisms of community assemblies of larch forests in China.

关键词： Beta-diversity Species turnover Nestedness-resultant Geographic distance Climatic distance Larch forest