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Synthesis of PE with Broad MWD Catalyzed by Supported Ziegler-Natta Catalyst Consisting of Cycloalkoxy Silane as IED

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China Petroleum Processing & Petrochemical Technology 2014年第2期16卷 91-96页

作者： Yu Mengshan Nie yanpei Zhou Lu Yi Jianjun Huang Qigu Gao Kejing Yang Wantai State Key Laboratory of Chemical Resource Engineering Key Laboratory of Carbon Fiber and Functional Polymers Ministry of Education Beijing University of Chemical Technology Lab for Synthetic Resin Research Institution of Petrochemical Technology China National Petroleum Corporation

Two kinds of cycloalkoxy silane compounds were synthesized and used as the internal electron donors （IEDs） of supported Ziegler-Natta catalyst for ethylene polymerization to produce polyethylene with broader molecular weight distribution （MWD）, The effect of the structure and the amount of these IEDs on the polymerization performance was in- vestigated. The results implied that the molecular weight distribution of the obtained polyethylene could be adjusted by the incorporation of IEDs. SEM result showed that the morphology of catalyst particle was spherical and uniform in size distribution. The titanium content of these catalysts was higher, the active TiCl4 species were easily anchored on the support than that without adding IED, which was determined by ICE The GPC result confirmed that the polyethylene with broader molecular weight distribution in the range of from 23.4 to 25.6 was obtained using triethoxy-（-cyclopentyloxy）-silane （ED1） and triethoxy-（-cyclohexyloxyl）- silane （ED2） as the internal electron donors.

关键词： supported Ziegler-Natta catalyst polyethylene broader molecular weight distribution electron donor

Spiro-conjugated indenodiarylethenes: enabling steric-induced electronic tuning of photochromic and photoluminescent properties by spiro-conjugation

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Science China Chemistry 2020年第11期63卷 1659-1665页

作者： Tingting Huang Hongyu Liu Yawen Bang yanpei Wang Yuan Liang Xinhao Wang Yang Zhang Sheng Xie Zebing Zeng Ben Zhong Tang State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082China Jiurui Biotechnology Co. LtdZhangjiajie 427000China Department of Chemistry Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and ReconstructionThe Hong Kong University of Science&TechnologyHong KongChina Center for Aggregation-Induced Emission SCUT-HKUST Joint Research InstituteState Key Laboratory of Luminescent Materials and DevicesSouth China University of TechnologyGuangzhou 510640China

Light-operated excited-state photochemical reactions and the resulting photochromic materials have gained significant attention for their promising technological applications in molecular electronic and photonic *** obtain photochromic materials(e.g.,diarylethenes)with desired properties,the way to tune energy processes of the excited state is essentially important,from both fundamental and practical *** modified diarylethenes mostly focused on structural improvements to achieve efficient *** report here two new spiro-conjugated indenodiarylethenes(named,SFI-Th and SFI-Sul)with an orthogonally arranged spiroπ-*** spiro fluorene sterically constrains the free volume of photoactive side aromatic rings,while the spiro-conjugation points toward modulation of the decaying channels of excited-state energy,thus allowing for tuning photochromic *** spirodiarylethenes SFI-Th and SFI-Sul are readily accessible with low cost and show distinct photochromic and photoluminescent *** one hand,the SFI-Th bearing bisthienyl side rings,is an excellent photochromic switch showing high thermal stability and high fatigue resistance in both solution and amorphous state,likely benefited from steric-induced excited-state energy transfer into reversible photochemical reactions,owing to higherπ-orbital spiro-conjugation between the two molecular *** the other hand,the SFI-Sul with bissulfonyl side rings,most notably,displays quantitative photocyclization to yield SFI-Sulc upon ***,the ring-closed SFI-Sulc has an extremely slow photocycloreversion,and meanwhile immediately switches on emissive state with a strong fluorescence(Φf=0.57 in amorphous powder state).We study the modulated roles of spiroπ-scaffold in both cases computationally and experimentally,and attribute the facilitated photochemical reaction to the positively electronic effects of spiro-conjugation,and the photo-responsive radiative transitio

关键词： diarylethene photochromic reaction spiro-conjugation steric-induced electronic effect excited-state energy

Damping Property of Supersaturated ZnA127Ce Alloy during Natural Aging

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Journal of Materials Science & Technology 2001年第1期17卷 9-10页

作者： Jingpei XIE Yaomin ZHU yanpei SONG Xiaoying WANG and Quande CHEN Dept.of Material Engineering , Luoyang Institute of Technology, Luoyang 471039. China Dept.of Material Engineering Luoyang Institute of Technology

The microstructures and damping property of supersaturated ZnA127Ce alloy during natural aging have been investigated. H-800 TEM was mainly used to research the microstructures. The relationship between microstructure and damping property was primarily studied. The results showed that solution plus natural aging was the best heat treatment, which could improve the damping property. Both continuous precipitation and cellular reaction occurred during the aging. Continuous precipitation follows the sequence: β→spherical GP zones→elliptical GP zones→intermediate phase R→n. The cellular reaction can be written as follows:β→a+n+ε.

关键词： Ce Damping Property of Supersaturated ZnA127Ce Alloy during Natural Aging

Overlooked contribution of the biological pump to the Pacific Arctic nitrogen deficit

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Science China Earth Sciences 2022年第8期65卷 1477-1489页

作者： Hongliang LI Jianfang CHEN Diana RUIZ-PINO Jingjing ZHANG Haiyan JIN yanpei ZHUANG Youcheng BAI Jian REN Yangjie LI Key Laboratory of Marine Ecosystem Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou310012China State Key Laboratory of Satellite Ocean Environment Dynamics Hangzhou310012China Sorbonne Universités(UPMC UniversitéParis 06)-CNRS-IRD-MNHNLOCEAN Laboratory4 Place JussieuParisF-75005France Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai519080China Polar and Marine Research Institute Jimei UniversityXiamen361021China

The nutrient-rich Pacific Ocean seawater that flows through the Bering Strait into the Chukchi Sea is generally considered to be the most important source of nutrients to the Arctic euphotic *** inflow is characterized by nitrogen deficit and low nitrate/phosphate(N/P)ratios;this is ascribed to sedimentary denitrification on the Chukchi shelf by preoccupant ***,the Chukchi Sea also has high primary production,which raises the question of whether the biological pump may also significantly modulate nutrient properties of the ***,we show that nitrate concentrations of the Pacific inflow gradually decrease northward in association with notable biological *** phytoplankton N/P uptake ratio was 8.8±2.27,higher than the N/P ratio of Pacific inflow water(5-6).This uptake ratio,in combination with efficient vertical nitrogen export,serves to preferentially remove nitrogen(relative to phosphorus)from upper waters,thereby further intensifying the Arctic nitrogen ***,as large as about 111.7×10^(9)mol N yr^(−1)of nitrate was extra consumed,according to the real N/P uptake ratio rather than the ratio of the Pacific inflow,which may be as great as half the nitrogen loss ascribed to sedimentary *** findings suggest that besides sedimentary denitrification,biological disproportionate utilization of nutrients in the Chukchi Sea upper water is another important contributor to the nitrogen limitation and excess phosphorus in the upper Arctic *** the rapid Arctic change era,the predicted reinforced biological carbon pump could further impact the nutrient dynamics and biogeochemical process of the Arctic Ocean.

关键词： Nitrogen deficit Biological pump Nutrient Sinking particles Arctic Ocean

Decomposition of dioxin-like components in a DBD reactor combined with Hg/Ar electrodeless ultraviolet

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Plasma Science and Technology 2020年第3期22卷 34-39页

作者： Weixuan ZHAO Liping LIAN yanpei WU Yanghaichao LIU Renxi ZHANG Gang LUO Huiqi HOU Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention(LAP3) Institute of Environmental ScienceFudan UniversityShanghai 200433People’s Republic of China National Engineering Laboratory for VOCs Pollution Control Material&Technology University of Chinese Academy of SciencesBeijing 100049People’s Republic of China

A new combined reactor with Hg/Ar electrodeless ultraviolet(EDUV)activated by DBD for 3,4-dichlorodiphenyl ether abatement is *** effect of specific input energy and feeding gas component on 3,4-dichlorodiphenyl ether removal efficiency has been *** with a single DBD system,this new combined process performed a significant promotion on 3,4-dichlorodiphenyl ether *** results verified that active oxygen clearly contributed to the synergistic activity of DBD-EDUV *** of emission spectra showed that UV radiation of 253.7 nm could be detected in the DBD-EDUV ***,the products of DBD-EDUV process were analyzed via gas chromatographymass spectrometer(GC-MS)to reveal involved decomposition mechanism.

关键词： dielectric barrier discharge(DBD) dioxin-like 3,4-dichlorodiphenyl ether EDUV photolysis

NEW APPROACHES TO THE GRAPHICNESS OF A MATROID

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Systems Science and Mathematical Sciences 1999年第S1期12卷 31-42页

作者： LIU yanpei(Institute of Mathematics, Northern Jiaotong University, Beijing 100044 China)

This article provides some new characterizations for testing if a matroid isgraphic. One of them can be seen as a consequence deduced from the Wu’s theory on theplanarity of graphs.

关键词： Matroid graphicness basic order.

Phytoplankton composition and its ecological effect in subsurface cold pool of the northern Bering Sea in summer as revealed by HPLC derived pigment signatures

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Acta Oceanologica Sinica 2014年第6期33卷 103-111页

作者： ZHUANG yanpei JIN Haiyan LI Hongliang CHEN Jianfang WANG Bin CHEN Fajin BAI Youcheng LU Yong TIAN Shichao Laboratory of Marine Ecosystem and Biogeochemistry Second Institute of OceanographyState Oceanic Administration State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyState Oceanic Administration College of Ocean and Meteorology Guangdong Ocean University

CHEMTAX analysis of high-performance liquid chromatography （HPLC） pigment was conducted to study phytoplankton community structure in the northern Bering Sea shelf, where a seasonal subsurface cold pool emerges. The results showed that fucoxanthin （Fuco） and chlorophyll a （Chl a） were the most abundant diagnostic pigments, with the integrated water column values ranging from 141 to 2160 μg/m2 and 477 to 5 535 μg/m2, respectively. Moreover, a diatom bloom was identified at Sta. BB06 with the standing stock of Fuco up to 9214 μg/m3. The results of CHEMTAX suggested that the phytoplankton community in the northern Bering Sea shelf was dominated by diatoms and chrysophytes with an average relative contribu- tion to Chl a of 80% and 12%, respectively, followed by chlorophytes, dinoflagellates, and cryptophytes. Dia- toms were the absolutely dominant algae in the subsurface cold pool with a relative contribution exceeding 90%, while the contribution of chrysophytes was generally higher in oligotrophic upper water. Additionally, the presence of a cold pool would tend to favor accumulation of diatom biomass and a bloom that occurred beneath the halocline would be beneficial to organic matter sinks, which suggests that a large part of the phytoplankton biomass would settle to the seabed and support a rich benthic biomass.

关键词： pigment phytoplankton community structure CHEMTAX northern Bering Sea shelf subsurface cold pool

Nitrate δ^(15)N and δ^(18)O evidence for active biological transformation in the Changjiang Estuary and the adjacent East China Sea

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Acta Oceanologica Sinica 2013年第4期32卷 11-17页

作者： CHEN Fajin CHEN Jianfang JIA Guodong JIN Haiyan XU Jie YANG Zhi ZHUANG yanpei LIU Xizhen ZHANG Haisheng State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of Oceanography State Oceanic Administration College of Ocean and Meteorology Guangdong Ocean University Laboratory of Marine Ecosystem and Biogeochemistry of State Oceanic Administration Second Institute of Oceanography State Oceanic Administration Key Laboratory of Marginal Sea Geology of Chinese Academy of Sciences Guangzhou Institute of Geochemistry Chinese Academy of Sciences Division of Environment Hong Kong University of Science and Technology Clear Water Bay

The Changjiang Estuary has been considered as one of the most polluted estuaries in the world due to high nitrate （NO3） input, especially in spring and summer. In this study, 6~5N and t^180 of NO3, along with other chemical parameters in this area, were measured in spring to evaluate NO3 biogeochemical processes. A simple two end-members mixing model was used to examine the relative contribution of the Changjiang River Diluted Water and marine water to NO~ sources in the Changjiang Estuary and the adjacent East Chi- na Sea. The isotopic signals show that NO3 behaved relatively and conservatively in Transect F and Transect P where assimilation was weak possibly due to vertical mixing, while active assimilation and weak nitrifi- cation occurred in Transect D. Spatial difference in assimilation was indicated by the ~ 1：1 enrichment of S 15N and 6180 in the three transects, while spatial difference in nitrification was reflected by deviations of 15N and 6180 from assimilation line. Our results suggest that the input of the Changjiang River Diluted Wa- ter promoted NO3 assimilation possibly by stratifying the water column which favored the phytoplankton growth.

关键词： Changjiang Estuary nitrate nitrogen isotope oxygen isotope

Room-temperature phonon-coupled single-photon emission in hexagonal boron nitride

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 109-114页

作者： Jia-Min Lai Qing-Hai Tan Feilong Song Haonan Chang yanpei Lv Xue-Lu Liu Jinghua Teng Weibo Gao Ping-Heng Tan Jun Zhang State Key Laboratory of Superlattices and Microstructures Institute of SemiconductorsChinese Academy of SciencesBeijing100083China Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of Education&Research Institute of Materials Science Shanxi Normal UniversityTaiyuan 030000China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Division of Physics and Applied Physics School of Physical and Mathematical SciencesNanyang Technological UniversitySingapore 637371Singapore Institute of Materials Research and Engineering(IMRE) Agency for ScienceTechnology and Research(A*STAR)Singapore 138634Singapore

Photon-lattice(phonon)coupling is fundamental to light-matter interaction,particularly when it reaches the quantum limit of the phonon-coupled single-photon emission,which holds great potential for quantum manipulation and quantum information ***,we report single defect state-phonon coupling in hexagonal boron nitride(h BN)at room *** ultrabroad spectrum of single-photon emissions can be achieved by selecting the excitation *** photoluminescence excitation spectroscopy,we observe single-phonon-assisted resonance-enhanced single-photon emission,along with multiple phonon replicas that herald the creation of phonon Fock *** also develop a transition model to gain insight into the physical process behind the single defect state-phonon *** work sets the stage for manipulating electron-phonon coupling state with single quantum-level precision at room temperature.

关键词： temperature phonon hexagonal