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Chemical Research in Chinese Universities 2007年第1期23卷 31-34页

作者： lue chun-sheng ZHANG Yue-tao MU Ying Key Laboratory for Supramolecular Structure and Materials of Ministry of Education School of Chemistry Jilin University 130012 P. R. China Department of Chemical Engineering Daqing Petroleum Institute Daqing 161310 P. R. China

The copolymerization of ethylene with dieyclopentadiene （DCP） in the presence of a constrained geometry tetramethylcyclopentadi-enyl-phenoxytitanium catalyst [ 2,4-＇ Bu2-6-（ 2,3,4,5-Me4 -Cp ） -PhO ] TICl2, combined with AI（ iBu）3/Ph3C^＋ B（ CsF5 ）4^- cocatalyst system was studied. The copolymers that were formed were characterized by ＇ H and ,3 C NMR, differential scanning calorimetry （ DSC）, SEM, and X-ray diffraction （XRD） analyses. The re- suits of the analysis indicate that the copolymers of ethylene with dicyclopentadiene are amorphous and display two or more melting temperatures in their DSC diagrams. Moreover, the morphologies of the copolymers are quite different from that of polyethylenes.

关键词： Ethylene polymerization Dicyclopentadiene Copolymers Metalloeene Polyethylene

Chiral phosphoramidite ligand-modulated palladium auto-tandem catalysis for asymmetric dehydrogenative dienylation of imines with α-alkenes

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Science China Chemistry 2025年

作者： Zhong-sheng Nong Hao-Fan Qian Ying-chun Chen Pu-sheng Wang Liu-Zhu Gong Hefei National Research Center for Physical Sciences at the Microscale and Department of Chemistry University of Science and Technology of China Key Laboratory of Drug Targeting and Drug Delivery System (Sichuan University) Ministry of Education and Sichuan Research Center for Drug Precision Industrial Technology West China School of Pharmacy Sichuan University School of Materials and Chemistry Southwest University of Science and Technology

The development of efficient processes allowing rapid access to complex chiral molecules from easily available alkenes is a long-term pursuit in the synthetic chemistry community. Transition metal-catalyzed asymmetric functionalization of allylic C–H bond represents a unique alternative toward this goal. However, enantioselective dehydrogenative transformation of olefins to value-added optically enriched molecules remains yet to be discovered. Here, we report a highly enantioselective dehydrogenative dienylation of imines with unactivated α-alkenes driven by the synergistic action of palladium complex and carboxylic acid. Chiral phosphoramidite ligands turned out to be superior in modulating the performance of palladium autotandem catalysis and allowed a broad range of α-alkenes and imines to be transformed into chiral dienylamines. Mechanistic studies suggest that the dienes could be in situ generated from α-alkenes through a palladium(0)-mediated dehydrogenative process in the presence of excess benzoquinone oxidants, and then participated in the Pd-chiral phosphoramidite-catalyzed intermolecular vinylogous-type addition to the imines activated by the carboxylic acid co-catalyst. Notably, the second β-H elimination occurring in the dienylation event might be the turnover-limiting step.

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Single-cell transcriptomic profiling reveals ZEB1-mediated regulation in microglial subtypes and the impact of exercise on neuroinflammatory responses

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Traditional Medicine Research 2025年第2期10卷 55-64页

作者： Jin-Fang Wu Yi-sheng Chen Yu-chun Xie Department of Rehabilitation Medicine Jiangsu Province Geriatric HospitalNanjing 210024China Fujian Key Laboratory of Toxicant and Drug Toxicology Medical CollegeNingde Normal UniversityNingde 352100China Central Laboratory Jiangsu Province Geriatric HospitalNanjing 210024China

Background:This study aims to identify distinct cellular subtypes within brain tissue using single-cell transcriptomic analysis,focusing on specific biomarkers that differentiate cell types and the effects of traditional and exercise ***:Four samples were analyzed:older control(OC),older exercise(OE),younger control(YC),and younger exercise(YE).Single-cell RNA sequencing was used to distinguish cellular subtypes through their biomarker *** visualization included violin and t-SNE plots to illustrate biomarker expression across cell clusters such as oligodendrocytes,microglia,and ***,BV2 cells were exposed to amyloid-beta fragments to simulate Alzheimer’s disease,assessing the impact of exercise-induced cellular ***:Distinct cellular subtypes were identified:oligodendrocytes(MBP,St18),microglia(Dock8),and astrocytes(Aqp4,Gpc5).Sample OE was predominantly oligodendrocytes,while YE had more astrocytes,inhibitory neurons,and Canal-Retzius *** showed a significant presence of Olfm3+ganglion ***1 gene knockout revealed changes in SMAD family gene expression,which regulate *** stress levels were also ***:This profiling enhances our understanding of brain cellular functions and interactions,potentially informing targeted therapies in neurological *** may influence brain cell immune responses and cell death pathways by regulating specific gene expressions,offering new insights for treating neuroinflammation and degeneration.

关键词： single-cell transcriptomics brain tissue cellular subtypes biomarker expression neuronal diversity

Symbolic Computation Study of （2＋1）-Dimensional Dispersive Long Wave Equations

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Communications in Theoretical Physics 2006年第2X期46卷 199-202页

作者： lue Zhuo-sheng School of Science Beijing University of Post and Telecommunications Beijing 100876 China Key Laboratory of Mathematics Mechanization Academy of Mathematics and System Sciences the Chinese Academy of Sciences Beijing 100080 China Department of Computer Science Liaoning Normal University Dalian 116029 China

Seeking exact analytical solutions of nonlinear evolution equations is of fundamental importance in mathematlcal physics. In this paper, based on a constructive algorithm and symbolic computation, abundant new exact solutions of the （2＋1）-dimensional dispersive long wave equations are obtained, among which there are soliton-like solutions, mult-soliton-like solutions and formal periodic solutions, etc. Certain special solutions are considered and some interesting localized structures are revealed.

关键词： dispersive long wave equations symbolic computation exact solution localized structure

A mild and efficient method for nucleophilic aromatic fluorination using tetrabutylammonium fluoride as fluorinating reagent

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Chinese Chemical Letters 2010年第2期21卷 151-154页

作者： Hu, Yu Feng Luo, Jun lue, chun Xu Nanjing Univ Sci & Technol Sch Chem Engn Nanjing 210094 Peoples R China

Anhydrous tetrabutylammonium fluoride(TBAF_(anh).) has been found to be a highly efficient fluorinating reagent for nucleophilic aromatic fluorinations such as fluorodenitration or halogen exchange(Halex) *** products were formed in high to excellent yields under surprisingly mild reaction conditions and no phenol or ether side-products were detected in these reactions.

关键词： TBAF_(anh). Fluoroaromatics Fluorodenitration Halex

Properties of Nonlinear Transverse-Electric Waves in a Two-Core Optical Waveguide with a Nonlinear Cladding

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Chinese Physics Letters 1998年第7期15卷 501-503页

作者： MA chun-sheng Department of Electronic Engineering National Integrated Optoelectronics LaboratoryJilin UniversityChangchun 130023

Expressions of dispersion relation and propagation power are presented for the nonlinear transverse-electric(TE)waves in a two-core optical waveguide with a nonlinear *** properties of the nonlinear TE waves are *** is found that when the total core thickness and the distance between the two cores are sufficiently large,the power curves of the higher odd modes become very sharp in some narrow ranges of the effective refractive index,compared with those of the higher even modes.

关键词： Nonlinear nonlinear adding

Asymmetric Synthesis of Anisodine

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Chinese Chemical Letters 2005年第10期16卷 1287-1289页

作者： Yan Fen WU Wen lue Qiang LU Wen sheng ZHANG School of Pharmaceutical Sciences Peking University Beijing 100083

Anisodine was synthesized from 3α-hydroxy-6β-acetyltropine in 11 steps. Laevorotary isomer of anisodine was prepared from the asymmetric dihydroxylation of compound 10 via the osmium catalyzed process employing p-ch... 详细信息

关键词： Anisodine tropine alkaloid total synthesis.

Quantitative assessment of the surface crack density in thermal barrier coatings

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Acta Mechanica Sinica 2014年第2期30卷 167-174页

作者： Li Yang Zhi-chun Zhong Yi-chun Zhou chun-sheng Lu Key Laboratory of Low Dimensional Materials & Application Technology (Ministry of Education)/Faculty of Materials Optoelectronic & PhysicsXiangtan University Department of Mechanical Engineering Curtin University

In this paper, a modified shear-lag model is developed to calculate the surface crack density in thermal barrier coatings（TBCs）. The mechanical properties of TBCs are also measured to quantitatively assess their surface crack density. Acoustic emission（AE） and digital image correlation methods are applied to monitor the surface cracking in TBCs under tensile loading. The results show that the calculated surface crack density from the modified model is in agreement with that obtained from experiments. The surface cracking process of TBCs can be discriminated by their AE characteristics and strain evolution. Based on the correlation of energy released from cracking and its corresponding AE signals, a linear relationship is built up between the surface crack density and AE parameters, with the slope being dependent on the mechanical properties of TBCs.

关键词： Thermal barrier coatings Acoustic emission Surface crack density Quantitative assessment

Theoretical Study on the Reaction Mechanism of F_2+2HBr = 2HF+Br_2

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Chinese Journal of Structural Chemistry 2005年第11期24卷 1328-1333页

作者： SUN De-sheng WANG Zun-Yao YANG chun-sheng School of Chemistry and Chemical Engineering Nanjing University of Technology Jiangsu Nanjing 210009 China Department of Chemical Engineering Yancheng Institute of Technology Jiangsu Yancheng 224003 China

The gas phase reaction mechanism of F2 ＋ 2HBr = 2HF ＋ Br2 has been investigated by （U）MP2 at 6-311G＊＊ level, and a series of four-center and three-center transition states have been obtained. The reaction mechanism was achieved by comparing the activation energy of seven reaction paths, i.e. the dissociation energy of F2 is less than the activation energy of the bimolecular elementary reaction F2 ＋ HBr → HF ＋ BrF. Thus it is theoretically proved that the title reaction occurs more easily in the free radical reaction with three medium steps.

关键词： (U)MP2,transition state reaction mechanism free radical reaction.

Reactive oxygen species metabolism during the cadmium hyperaccumulation of a new hyperaccumulator Sedum alfredii (Crassulaceae)

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Journal of Environmental Sciences 2007年第11期19卷 1311-1317页

作者： ZHANG Zhong-chun QIU Bao-sheng College of Life Sciences Huazhong Normal University Wuhan 430079 China

Sedum alfredii Hance, a newly discovered hyperaccumulator, could serve as a good material for phytoremediation of Cd polluted sites. Malondialdehyde （MDA）, reactive oxygen species （ROS） and antioxidases （catalase （CAT）; superoxide dismutase （SOD）; peroxidase （POD）） in the leaf were determined when S. alfredii was treated for 15 d with various CdC12 concentrations ranging from 0 to 800 μmol/L. The results showed that the production rate of 2＇,7＇-dichlorofluorescein （DCF）, which is an indicator of ROS level, reached up to the maximum at 400 μmol/L CdCl2 and then declined with the increase of CdCl2 concentration, while MDA accumulation tended to increase. CAT activity was significantly inhibited at all tested CdCl2 concentrations and SOD activity was sharply suppressed at 800 μmol/L CdCl2. However, the enhancement of POD activity was observed when CdCl2 concentration was higher than 400 μmol/L. In addition, its activity increased when treated with 600 μmol/L CdCl2 for more than 5 d. When sodium benzoate, a free radical scavenger, was added, S. alfredii was a little more sensitive to Cd toxicity than that exposed to Cd alone, and the Cd accumulation tended to decline with the increase of sodium benzoate concentration. It came to the conclusions that POD played an important role during Cd hyperaccumulation, and the accumulation of ROS induced by Cd treatment might be involved in Cd hyperaccumulation.

关键词： cadmium hyperaccumulation reactive oxygen species Sedum alfredii