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Theoretical Studies on the Iodine-catalyzed Nucleophilic Addition of Acetone with Five-membered Heterocycles

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Chemical Research in Chinese Universities 2008年第4期24卷 520-524页

作者： WANG Yan-hua li li chen xue-song College of Biology and Environment Engineering Zhejiang Shuren University Hangzhou 310015 P. R. China

The iodine-catalyzed nucleophilic addition reactions of pyrrole, furan, or thiophene with acetone were studied in gas and solvent by the density functional theory at the level of Lanl2DZ^＊. It was seen that the halogen bond between iodine and carbonyl oxygen appeared to have an important catalytic effect on such reactions, and the first iodine molecule maximally diminished the barrier height by 41 kJ/mol, while the second iodine molecule could not improve such reactions largely. It was concluded that the C2-addition was generally more favorable than the C3-addition for the three heterocycles; however, iodine considerably more effectively catalyzed the C3-addition than the C2-addition for pyrrole. It was also revealed by PCM calculation that the iodine-catalyzed nucleophilic additions occurred more easily in solvent than in gas, which explained the experiment performed by Bandgar et al..

关键词： Halogen bond, Catalytic effect Nucleophilic addition Density functional theory

Spatial-Temporal Patterns in a Dielectric Barrier Discharge under Narrow Boundary Conditions in Argon at Atmospheric Pressure

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Chinese Physics Letters 2011年第4期28卷 152-155页

作者： li xue-chen JIA Peng-Ying ZHAO Na College of Physics Science and Technology Hebei UniversityBaoding 071002

Pattern formation phenomena are investigated in a dielectric barrier discharge under narrow boundary conditions in argon at atmospheric *** discharge shows various scenarios with the increasing applied *** is the first observation of alternating single spot and pair spots pattern and of a moving striation pattern in a dielectric barrier discharge *** spatial-temporal correlations between discharge filaments in these patterns are measured by an optical *** results show that the zigzag pattern is an interleaving of two sub-structure patterns,which ignites once for each sub-pattern per half cycle of the applied *** is a temporal sequence inversion in consecutive half-cycles for the two *** pattern of alternating single spot and pair spots is also an interleaving of two sub-structure ***,the pair spots sub-pattern ignites twice and the single spot sub-pattern ignites once per half cycle of the applied voltage.

关键词： method dielectric narrow

Bond Order Analysis, Packing Ratio, and Electronic Structures of Two Structural Polymorphs Based on Manganese Complexes

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Chinese Journal of Chemistry 2017年第6期35卷 927-930页

作者： xue-li chen Yuexing Zhang Ming-Yuan Zhang Ming-Hua Zeng Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials Ministry-of-Education Key Laboratory fi〉r the Synthesis and Applieation of Organic Functional Molecules School of Chemistry and Chemical Engineering Hubei University Wuhan Hubei 430062 China Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources Guangxi Normal University Guilin Guangxi 541004 China

The bond order and packing ratios in the single-crystal of the two structural polymorphs as well as the detailed electronic structures of the molecular model were studied using density functional theory. The strength of different Mn coordination bonds was analyzed in detail through Mayer bond order. Besides bond length, many other factors such as the orientation of ligand and nature of metal also significantly influence the bond order. Packing ratios cal- culated using cluster model reveals that packing along b direction in Dimer is more favorable than other directions due to the associated interactions of π-π and CI…H when packing in this direction. Electronic structure helps ex- plain the formation of Dimer from monomer or direct forming of Chain from ligand/Cl and metal. This would shed light on further understanding the importance of supramolecular interaction on crystal engineering.

关键词： structural polymorphs manganese bond order cluster model density functional theory

Neuroprotective effects of tetrandrine against vascular dementia

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Neural Regeneration Research 2016年第3期11卷 454-459页

作者： Yan-ling Lv Ze-zhi Wu li-xue chen Bai-xue Wu lian-lian chen Guang-cheng Qin Bei Gui Ji-ying Zhou Laboratory Research Center the First Affiliated Hospital of Chongqing Medical University Key Laboratory of Biorheological Science and Technology of the State Ministry of Education College of BioengineeringChongqing University

Tetrandrine is one of the major active ingredients in Menispermaceae Stephania tetrandra ***,and has specific therapeutic effects in ischemic cerebrovascular *** use in vascular dementia has not been studied ***,we investigated whether tetrandrine would improve behavioral and cellular impairments in a two-vessel occlusion rat model of chronic vascular *** weeks after model establishment,rats were injected intraperitoneally with 10 or 30 mg/kg tetrandrine every other day for 4 *** assessment in the Morris water maze showed that model rats had longer escape latencies in training trials,and spent less time swimming in the target quadrant in probe trials,than sham-operated ***,rats that had received tetrandrine showed shorter escape latencies and longer target quadrant swimming time than untreated model ***-eosin and Nissl staining revealed less neuronal necrosis and pathological damage,and more living cells,in the hippocampus of rats treated with tetrandrine than in untreated model *** blot assay showed that interleukin-1β expression,and phosphorylation of the N-methyl-D-aspartate 2B receptor at tyrosine 1472,were lower in model rats that received tetrandrine than in those that did *** present findings suggest that tetrandrine may be neuroprotective in chronic vascular dementia by reducing interleukin-1β expression,N-methyl-D-aspartate receptor 2B phosphorylation at tyrosine 1472,and neuronal necrosis.

关键词： nerve regeneration tetrandrine ischemic cerebrovascular disease vascular dementia N-methyl-D-aspartic acid receptor 2B N-methyl-D-aspartate receptor 2B phosphorylation at tyrosine 1472 interleukin-1β neuronal necrosis neural regeneration

Predicting Critical Conditions and Stress-Strain Curves for Dynamic Recrystallization in SPHC Steel

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Journal of Iron and Steel Research International 2010年第7期17卷 51-57页

作者： WU Lai-zhi li xue-song chen Jun ZHANG Hong-bing CUI Zhen-shan Department of Plasticity Technology Shanghai Jiaotong University Shanghai 200030 China

The hot compression tests on an SPHC steel were carried out in the temperature range of 900-1150 ℃ and strain rate range of 0.1-10 s-1,in which the maximum true strain is *** activation energy of test steel was calculated,to be 299.4 kJ/*** critical stresses and strains for initiation of dynamic recrystallization were determined based on changes of the work hardening rate（θ）as a function of the flow stress（σ）or strain（ε）,*** dependence of the peak strain（εp）,the peak stress（σp）,and the steady state stress（σs）were determined based on the Zener-Hollomen *** mathematical models of the flow stress evolution were established in the hardening and dynamic recovery region and dynamic recrystallization region,*** average error between experimental curves and predicted ones was around 3.26%.

关键词： flow stress dynamic recrystallization critical stress critical strain SPHC steel

Can Industrial Structure Upgrading Restrain Industrial Land Expansion?Evidence from China

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Chinese Geographical Science 2024年第3期34卷 504-518页

作者： chen Wei li Qiao ZHANG Sun ZHOU xue College of Economics and Management Northwest A&F UniversityYangling Shaanxi 712100China Institute of Geographic Sciences&Natural Resources Research Chinese Academy of SciencesBeijing 100101China

China has made great achievements in industrial development and is transforming into a powerful manufacturing ***,the industrial land scale is also ***,whether industrial structure upgrading achieves the purpose of restraining industrial land expansion remains *** calculating the industrial land structure index(ILSI)and industrial land expansion scale(ILES),this study analyzed their temporal and spatial distribution characteristics at both regional and city levels from 2007to 2020 in *** show that industrial land expansion presents a different trend in the four regions,the ILES in the eastern region is the largest,and the speed of industrial land expansion has declined since 2013,but it has gradually increased since *** ILSI of the eastern and central regions is higher than that of the western and northeastern ***,a spatial Durbin model(SDM)has been established to estimate the spatial effect of industrial structure upgrading on industrial land expansion from 2007 ***,industrial structure upgrading has not slowed industrial land *** eastern and western regions require a greater amount of industrial land while upgrading the industrial *** improvement of the infrastructure level and international trade level has promoted industrial land expansion.

关键词： industrial development industrial structure upgrading industrial land expansion regional differences China

Transcription factor Foxp1 is essential for the induction of choroidal neovascularization

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Eye and Vision 2024年第3期10卷 1-12页

作者： Meifang Yan Junjian li li Yan xue li Jie-Guang chen School of Ophthalmology and Optometry and Eye Hospital Wenzhou Medical UniversityState Key Laboratory of OptometryOphthalmology and Vision Scienceand Zhejiang Provincial Key Laboratory of Optometry and Ophthalmology270 Xueyuan RoadWenzhouZhejiang325027People’s Republic of China Joint Shantou International Eye Center(JSIEC)of Shantou University and the Chinese University of Hong Kong ShantouGuangdong515000People’s Republic of China

Background The exudative form of age-related macular degeneration(AMD)is characterized by abnormal blood vessel growth,which is stimulated by vascular endothelial growth factor(VEGF)released from retinal pigment epithelium(RPE).The angiogenic behaviors of vascular endothelial cells in vitro depend on forkhead box protein P1(Foxp1),a transcription repressor widely expressed in human and murine tissues during *** this study,we aimed to determine whether loss of Foxp1 affects laser-induced choroidal neovascularization(CNV)in *** Eye-selective deletion of Foxp1 was obtained by crossing Foxp1flox/flox with Six3-Cre *** photocoagulation was delivered to six-to eight-week-old mice to induce *** expression of Foxp1 and Cre was determined by immunofluorescence in cryostat sections of the *** fluorescein angiography(FFA),optical coherence tomography(OCT),and B4 isolectin staining were applied to analyze the leakage,bulge height,and area of CNV lesions,***-choroid tissues were isolated for the determination of VEGF and pigment epithelium derived factor(PEDF)by Western *** Foxp1 was expressed in retinal ganglion cells,RPE,and the choroidal endothelial *** photocoagulation increased the number of Foxp1+-endothelial cells and induced ***3-Cre reduced Foxp1 expression in RPE but not the endothelium,leading to a lower level of VEGF in the ***1 knockout inhibited pathological angiogenesis and vascular leakage of the laser-induced CNV *** Foxp1 regulates the expression of VEGF in the RPE,and inhibition of Foxp1 could potentially be a novel strategy for the prevention and therapy of neovascularization related to AMD.

关键词： Foxp1 Choroidal neovascularization Angiogenesis Laser photocoagulation Age-related macular degeneration

Efficient capture of difluorocarbene by pyridinium 1,4-zwitterionic thiolates:A concise synthesis of difluoromethylene-containing 1,4-thiazine derivatives

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Chinese Chemical Letters 2024年第4期35卷 367-370页

作者： Zhiwei chen Heyun Sheng xue li Menghan chen Xin li Qiuling Song Institute of Next Generation Matter Transformation College of Materials Science&Engineering and College of Chemical Engineering at Huaqiao UniversityXiamen 361021China Fujian University Key Laboratory of Molecule Synthesis and Function Discovery College of ChemistryFuzhou UniversityFuzhou 350108China State Key Laboratory of Organometallic Chemistry and Key Laboratory of Organofluorine Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

A practical method for the construction of difluoromethylene-containing 1,4-thiazine moieties using readily available diethyl bromodifluoromethanephosphonate(BrCF_(2)PO(OEt)_(2))as difluorocarbene precusor has been *** transformation features the efficient capture of difluorocarbene by pyridinium 1,4-zwitterionic thiolates.A series of structurally novel and functionalized difluoromethylene-containing 1,4-thiazine derivatives were thus synthesized in good yields.

关键词： Difluoromethylene Pyridinium 1 4-zwitterionic thiolates 1 4-Thiazine derivatives

LaMnO_(3)/Co_(3)O_(4) nanocomposite for enhanced triethylamine sensing properties

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Journal of Rare Earths 2024年第4期42卷 733-742页

作者： Jian Zhang Yanping chen ling li xue chen Wenya An Xiujuan Qian Yuye Tao School of Science Shandong Jianzhu UniversityJinan250100China

LaMnO_(3) modified Co_(3)O_(4) nanocomposites were prepared by simple hydrothermal method co mbined with sol-gel *** gas sensitivity properties of pure Co_(3)O_(4) and LaMnO_(3)/Co_(3)O_(4) with different composite proportions are *** is found that 0.6-LMO/Co_(3)O_(4) sensor has higher sensitivity to triethylamine(TEA)than pure Co_(3)O_(4) sensor,which is improved by 9.27 *** the working temperature is reduced from 150 to 130℃.Besides,it has excellent gas selectivity and *** improvement of the gas sensitivity of LaMnO_(3)/Co_(3)O_(4) sensor may be due to the fact that LaMnO_(3) is an effective catalyst,and the catalytic performance perhaps is beneficial to improving the sensing *** addition,the formation of p-p heterojunctions may be the key factor to improve the gas sensing *** work provides a new Co_(3)O_(4)-based gas sensing material for the detection of TEA.

关键词： Gas sensing Co_(3)O_(4) LaMnO_(3) Triethylamine Rareearths