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Chinese Chemical Letters 2006年第7期17卷 853-856页

作者： ye WANG Zhan Zhu LIU ye feng tang Shi Zhi CHEN Institute of Materia Medica Chinese Academy of Medical Sciences ＆ Peking Union Medical College Beijing 100050

Two functionalized pentacyclic compounds 12a, 12b were constructed via a highly efficient synthetic route, employing a tricyclic amino aldehyde as the key intermediate. The crucial steps involved coupling of two segme... 详细信息

关键词： Ecteinascidin saframycin tetrahydroisoquinoline Pictet-Spengler reaction.

Formation of Benzyl Oxazole, A Competitive Path with the Classical Bishler-Napieralski Reaction

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Chinese Chemical Letters 2001年第11期12卷 947-950页

作者： Zhan Zhu LIU ye feng tang Shi Zhi CHEN Institute of Materia Medica Chinese Academy of Material Sciences&Peking Union Medical CollegeBeijing 100050

Several aromatic ring-substituted N-acetyl-phenylalanine methyl esters were treated with POCl3 in refluxing benzene, which is the typical condition of B-N reaction. It was found that the normal B-N product 3, 4-dihydroisoquinoline-3-carboxylic acid methyl ester and/or 5-benzyl-2-methyl-4-methoxy oxazole could be obtained. The result depended mainly upon the electron-donating property of the substitutes on the benzene ring. Strong electron-donating groups located at para- or ortho- to the cyclization site will facilitate the formation of the normal B-N product 2. On the other hand, the absence or weak electron-donating groups tended to yield the oxazole product 3. It was established that the formation of benzyl oxazole is the competitive path with the B-N reaction. In this article, an explanation was given based on the mechanism of Bishler-Napieralski reaction.

关键词： Bishler-Napieralski reaction benzyl oxazole 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid N-acetyl-phenytalanine methyl ester

Formal synthesis of(+)-tashiromine and study toward the total synthesis of(+)-stemoamide

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Chinese Chemical Letters 2013年第11期24卷 953-956页

作者： Yue-Jie Chen Rui-Yang Bao Xiao-Dong Zhang ye-feng tang The Comprehensive AIDS Research Center Department of Pharmacology & Pharmaceutical Sciences School of Medicine Tsinghua University

An effcient formal synthesis of（＋）-tashiromine was achieved by employing an intermolecular asymmetric Mannich-type reaction as the key ***,a novel approach toward the total synthesis of（＋）-stemoamide through dyo... 详细信息

关键词： Stemoamide Tashiromine Dyotropic rearrangement b-Lactone Total synthesis

Failure behavior and strength model of blocky rock mass with and without rockbolts

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International Journal of Mining Science and Technology 2024年第6期34卷 747-762页

作者： Chun Zhu Xiansen Xing Manchao He Zhicheng tang feng Xiong Zuyang ye Chaoshui Xu School of Earth Sciences and Engineering Hohai UniversityNanjing 210024China Key Laboratory of Water Management and Water Security for yellow River Basin Ministry of Water Resources(under construction)Zhengzhou 450003China State Key Laboratory for Geomechanics&Deep Underground Engineering China University of Mining and TechnologyBeijing 10083China Faculty of Engineering China University of GeosciencesWuhan 430074China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China School of Resource and Environmental Engineering Wuhan University of Science and TechnologyWuhan 430081China School of Chemical Engineering Faculty of SciencesEngineering and TechnologyThe University of AdelaideAdeliade 5005Australia

To better understand the failure behaviours and strength of bolt-reinforced blocky rocks,large scale extensive laboratory experiments are carried out on blocky rock-like specimens with and without rockbolt *** results show that both shear failure and tensile failure along joint surfaces are observed but the shear failure is a main controlling factor for the peak strength of the rock mass with and without *** rockbolts are necked and shear deformation simultaneously happens in bolt reinforced rock *** the joint dip angle increases,the joint shear failure becomes more *** number of rockbolts has a significant impact on the peak strain and uniaxial compressive strength(UCS),but little influence on the deformation modulus of the rock *** the Winkler beam model to represent the rockbolt behaviours,an analytical model for the prediction of the strength of boltreinforced blocky rocks is *** agreement between the UCS values predicted by proposed model and obtained from experiments suggest an encouraging performance of the proposed *** addition,the performance of the proposed model is further assessed using published results in the literature,indicating the proposed model can be used effectively in the prediction of UCS of bolt-reinforced blocky rocks.

关键词： Blocky rock mass Rockbolt ground support Uniaxial compression test Failure mechanism Uniaxial compressive strength model

Study on the Total Synthesis of Et 743 and its Analogues: Synthesis of a Tricyclic Intermediate and its 11-Epimer

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Chinese Chemical Letters 2003年第10期14卷 996-998页

作者： ye feng tang, Zhan Zhu LIU, Shi Zhi CHENInstitute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union MedicalCollege, Beijing 100050 Institute of Materia Medica Chinese Academy of Medical Sciences & Peking Union Medical College Beijing 100050

The tricyclic compound 1, a key intermediate of the pentacyclic core of Et 743 and its analogues, was synthesized. Its 11-epimer was found as the product of racemization when BOP was used as the coupling agent, but not when BOP-C1 used in the same reaction. The stereochemistry of both isomers was confirmed on basis of the 1H NMR and NOE-difference spectra.

关键词： Et 743 tricyclic compound synthesis stereochemistry.

Commentary:Mammokine directs beige adipocytes to reserve energy for milk production in breast

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Acta Pharmaceutica Sinica B 2024年第3期14卷 1472-1476页

作者： Lina tang Jianping ye Metabolic Disease Research Center Zhengzhou University Affiliated Zhengzhou Central HospitalZhengzhou 450007China Research Center for Basic Medicine Academy of Medical SciencesZhengzhou UniversityZhengzhou 450052China

Beige/brown adipocytes play a crucial role in regulating the body’s overall energy *** thermogenic function is under the influence of various tissues,including the brain,muscles,and ***,the breast tissue is not in th... 详细信息

关键词： Beige Breast Epitheliail cells scRNA-seq Thermogenesis

Biodegradation pathway and mechanism of tri (2-chloropropyl) phosphate by Providencia rettgeri

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Journal of Environmental Sciences 2024年第10期144卷 26-34页

作者： Jinming ye Shaoyu tang Rongliang Qiu Shuona Chen Huiling Liu College of Natural Resources and Environment of South China Agricultural University Guangzhou 510642China Guangdong Provincial Key Laboratory of Agricultural&Rural Pollution Abatement and Environmental Safety Guangzhou 510642China Research Center for Eco-Environmental Engineering Dongguan University of TechnologyDongguan 523808China

Tri(2-chloropropyl)phosphate(TCPP)was an emerging contaminant of global concern because of its frequent occurrence,potential toxic effects,and persistence in the *** degradation might be an efficient and safe removal method,but limited information was *** this study,Providencia rettgeri was isolated from contaminated sediment and showed it could use TCPP as unique phosphorus source to promote growth,and decompose 34.7%of TCPP(1 mg/L)within 5 *** microbial inoculation and the initial concentration of TCPP could affect the biodegradation *** study results indicated that TCPP decomposition by Providencia rettgeri was mainly via phosphoester bond hydrolysis,evidenced by the production of bis(2-chloropropyl)phosphate(C6H13Cl2PO4)and mono-chloropropyl phosphate(C3H8ClPO4).Both intracellular and extracellular enzymes could degrade TCPP,but intracellular degradation was dominant in the later reaction stage,and the presence of Cu2+ions had a promoting *** findings developed novel insights into the potential mechanism of TCPP microbial degradation.

关键词： Chlorinated organophosphate flame retardants Microbial degradation Degradation pathway Providencia rettgeri Tri(2-chloropropyl)phosphate

A rapid field crop data collection method for complexity cropping patterns using UAV and YOLOv3

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Frontiers of Earth Science 2024年第1期18卷 242-255页

作者： Huifang ZHANG Binyao WANG Zhonggang tang Jiahui XUE Ruihang CHEN Hongcheng KAN Shumiao LU Lina feng ye HE Shuhua YI Institute of Fragile Eco-environment Nantong UniversityNantong 226019China School of Geographic Science Nantong UniversityNantong 226019China Nantong Key Laboratory of Spatial Information Technology R&D and Application School of Geographic ScienceNantong UniversityNantong 226019China

Crop type mapping using remote sensing is critical for global agricultural monitoring and food ***,the complexity of crop planting patternsand spatial heterogeneity pose significant challenges to field data collection,thereby limiting the accuracy of remotely sensed crop *** study proposed a new approach for rapidly collecting field crop data by integrating unmanned aerial vehicle(UAV)images with the YOLOv3(You Only Look Once version 3)*** impacts of UAV flight altitude and the number of training samples on the accuracy of crop identification models were investigated using peanut,soybean,and maize as *** results showed that the average Fl-score for crop type detection accuracy reached 0.91 when utilizing UAV images captured at an altitude of 20 *** addition,a positive correlation was observed between identification accuracy and the number of training *** model developed in this study can rapidly and automatically identify crop types from UAV images,which significantly improves the survey efficiency and provides an innovative solution for acquiring field crop data in large areas.

关键词： deep learning flight altitude crop survey peanut soybean maize

Estimation of the anisotropy of hydraulic conductivity through 3D fracture networks using the directional geological entropy

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International Journal of Mining Science and Technology 2024年第2期34卷 137-148页

作者： Chuangbing Zhou Zuyang ye Chi Yao Xincheng Fan feng Xiong School of Infrastructure Engineering Nanchang UniversityNanchang 330031China b School of Resource and Environmental Engineering Wuhan University of Science and TechnologyWuhan 430081China School of Engineering China University of GeosciencesWuhan 430074China

With an extension of the geological entropy concept in porous media,the approach called directional entrogram is applied to link hydraulic behavior to the anisotropy of the 3D fracture networks.A metric called directional entropic scale is used to measure the anisotropy of spatial order in different *** with the traditional connectivity indexes based on the statistics of fracture geometry,the directional entropic scale is capable to quantify the anisotropy of connectivity and hydraulic conductivity in heterogeneous 3D fracture *** to the numerical analysis of directional entrogram and fluid flow in a number of the 3D fracture networks,the hydraulic conductivities and entropic scales in different directions both increase with spatial order(i.e.,trace length decreasing and spacing increasing)and are independent of the dip *** a result,the nonlinear correlation between the hydraulic conductivities and entropic scales from different directions can be unified as quadratic polynomial function,which can shed light on the anisotropic effect of spatial order and global entropy on the heterogeneous hydraulic behaviors.

关键词： 3D fracture network Geological entropy Directional entropic scale Anisotropy Hydraulic conductivity

Ultralow friction PTFE/PEEK heterolayer:A new solid lubrication approach toward simplicity

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Friction 2024年第1期12卷 120-135页

作者： Wei SUN Jiaxin ye Qingrui SONG Yi feng Xiaojun LIU School of Materials Science and Engineering Hefei University of TechnologyHefei 230009China Institute of Tribology School of Mechanical EngineeringHefei University of TechnologyHefei 230009China

Tribological applications of polytetrafluoroethylene(PTFE)are often limited by technological complexity to overcome its poor wear ***,a PTFE/polyetheretherketone(PEEK)heterolayer(HL)was proposed and evaluated as a new solid lubrication ***-on-disk tribometry found the lowest friction coefficient(μ)of 0.031 and ultralow wear for the PEEK/HL under typical *** friction coefficient of the HL surpasses those of the state-of-the-art polymeric coatings/composites by at least 200%,and approaches that of highly lubricated *** investigations revealed multi-length physical and chemical heterogeneity of the HL that best facilitates a tribofilm with high subsurface stability and surface *** technological simplicity and robustness of the HL’s high lubricity make it a promising new type of solid lubrication toward greater reliability and longevity.

关键词： ultralow friction anti-wear polytetrafluoroethylene(PTFE) heterolayer(HL)