检索结果-南通市图书馆

Photoinduced copper-catalyzed alkoxyl radical-triggered ring-expansion/aminocarbonylation cascade

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第6期35卷 331-336页

作者： Jing-Qi Tao Shuai Liu tian-yu zhang Hong Xin Xu Yang Xin-Hua Duan Li-Na Guo Department of Chemistry School of ChemistryXi’an Key Laboratory of Sustainable Energy Material Chemistry and Engineering Research Center of Energy Storage Materials and DevicesMinistry of EducationXi’an Jiaotong UniversityXi’an 710049China School of Electrical Engineering Xi’an Jiaotong UniversityXi’an 710049China State Key Laboratory of Applied Organic Chemistry Lanzhou UniversityLanzhou 730000China

A photoinduced copper-catalyzed alkoxyl triggered C-C bond cleavage/aminocarbonylation cascade is *** adjusting the structure of alkoxyl radical precursors,functionalized lactones and ketoamides were synthesized with good yields and excellent functional group tolerance under redox-neutral ***,this protocol enables the integration of lactone fragments with many amine drugs and drug fragments.

关键词： Copper catalysis Ring-expansion Aminocarbonylatioin Macrolactones Keto-amides

A low-cost and high-performance technique for adaptive optics static wavefront correction

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2021年第7期21卷 261-268页

作者： De-Qing Ren tian-yu zhang Gang Wang California State University Northridge Department of Physics and AstronomyNorthridgeCA 91330USA National Astronomical Observatories/Nanjing Institute of Astronomical Optics and Technology Chinese Academy of SciencesNanjing 210042China CAS Key Laboratory of Astronomical Optics and Technology Nanjing Institute of Astronomical Optics and TechnologyNanjing 210042China University of Chinese Academy of Sciences Beijing 100049China

Non-Common Path Error(NCPE) is one of the factors that limit an Adaptive Optics(AO)system from delivering ultra-high performance. To correct the NCPE associated static aberration, we propose a simple but robust and high-performance pupil-plane based wavefront measurement and correction technique, which can copy a single-mode fiber generated perfect wavefront to the AO system via an iteration optimization process, and the NCPE can be effectively corrected by directly commanding the Deformable Mirror(DM) of the AO system. Compared with the previous focal-plane based approach that uses focal plane based Point Spread Function(PSF) for correction evaluation, the pupil-plane based approach can be reliably and rapidly converged to a global optimization result and provides better performance, in particular for an AO system with a large initial static wavefront error. This technique we proposed can be implemented in astronomical AO systems where extremely high performance is required.

关键词： astronomical instrumentation:adaptive optics astronomical instrumentation:high angular resolution astronomical techniques:high angular resolution

Effect of low-temperature ausforming on bainitic transformation and mechanical properties in ultrahigh-strength bainitic steel

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2023年第9期30卷 1843-1853页

作者： tian-yu zhang Ling-yu Wang yu Wang Jun Hu Hong-shuang Di Wei Xu State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819LiaoningChina

Low-temperature ausforming(LT-AF)prior to bainitic transformation leads to a noticeable acceleration of bainitic transformation kinetics;however,the effect of LT-AF on the retained austenite(RA)features and the resulting mechanical properties is still ***-AF was applied to ultrahigh-strength bainitic steel before *** deformation behavior and the resulting dislocation substructures were investigated by thermomechanical simulator and transmission electron microscopy(TEM).The planar dislocation structures produced during deformation at 350℃ accelerate the bainitic transformation kinetics during isothermal *** effect of LT-AF on the bainitic transformation kinetics and the features of RA was elucidated via dilatometer measurement,TEM,scanning electron microscopy,and X-ray *** is observed that LT-AF not only retains more RA content but also facilitates improved RA *** trend is mainly due to the large amounts of planar dislocations in RA and bainitic laths inherited from undercooled austenite caused by LT-AF,the decrease in bainitic sheaves size,and the increase in filmy RA content compared to the sample without ausforming.A large fraction of filmy RA with high stability and the refinement of bainitic sheaves obtained by LT-AF remarkably enhance the strain hardening capacity and achieve significantly better ductility compared to the directly austempered sample.

关键词： Ultrahigh-strength bainitic steel Bainitic transformation Low-temperature ausforming Retained austenite Strain hardening rate

n-Type Semiconductive Polymers Based on Pyrene-1,5,6,10-Tetracarboxyl Diimide

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

高分子科学:英文版 2023年第10期41卷 1584-1590页

作者： Xu-Dong Bai Zi-Di yu Yao Li tian-yu zhang Di zhang Jie-yu Wang Jian Pei Da-Hui Zhao Beijing National Laboratory for Molecular Sciences Centre of Soft Matter Science and Engineering and Key Lab of Polymer Chemistry&Physics of Ministry of EducationCollege of ChemistryPeking UniversityBeijing100871China

Donor-acceptor(D-A)conjugated polymers comprising electron-deficient aromatic dicarboximide units represent an important type of organic semiconductors,especially for electron transporting ***-1,5,6,10-tetracarboxyl diimide(PyDI),a new PAH dicarboximide molecule recently reported by us,provides a fine balance between the electron-stabilizing ability andπ-stacking tendency,as compared to the naphthalenediimide(NDI)and perylenediimide(PDI)*** this study,using thienylene-vinylene-thienylene(TVT)and biselenophene(BS)as the electron donating comonomer,along with PyDI as the acceptor moiety,we develop two new D-A type conjugated polymers,which exhibit impressive electron-transporting ***,in the solution-processed OFET devices,electron mobility of 0.18 and 0.20 cm^(2)·V^(−1)·s^(−1) are achieved with these polymers,*** findings further prove the optimal potential of PyDI for application as an electron-acceptor building block in the development of polymeric n-type semiconductors among all various high-performance functional D-A polymers.

关键词： Pyrenedimide Conjugated polymers Donor-acceptor Organic electronics

Geochemistry and genesis of the Nadun Nb-enriched arc basalt in the Duolong mineral district,western Tibet:Indication of ridge subduction

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2022年第1期13卷 230-243页

作者： tian-yu zhang Jianghong Deng Ming Wang Cai Li Lipeng zhang Weidong Sun Center of Deep Sea Research Institute of OceanologyCenter for Ocean Mega-ScienceChinese Academy of SciencesQingdao 266071China Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China College of Earth Sciences Jilin UniversityChangchun 130061China School of Marine Sciences University of Chinese Academy of SciencesBeijing 100049China

The Duolong mineral district in western Tibet is one of the largest porphyry Cu–Au deposit fields with significant metallogenic potential in *** tectonic environment relevant to Early Cretaceous Cu–Au mineralization remains *** we report new whole-rock major and trace element,and Sr-Nd-Hf-Pb isotopic data for the newly discovered basalt in the Nadun area,Duolong mineral district,to decipher their genesis and further constrain the tectonic environment.A contemporaneous rhyolite sample interbedded with the basalt in the lower part of the volcanic section in the Nadun area yields an LA-ICP-MS zircon U–Pb age of 122.5±1.2 *** basalt samples exhibit high-K calc-alkaline/shoshonite properties and are enriched in high field strength elements,e.g.,high Ti O_(2)(1.43–1.79 wt.%)and Nb(14.6–19.5 ppm)contents,with high Nb/La ratios(0.4–0.6),which are compositionally comparable to those of Nb-enriched arc basalts(NEABs).The(^(87) Sr/^(86) Sr)iratios of 0.7052 to 0.7056,negative eNd(t)(-0.7 to-0.2)and eHf(t)values(+6.0 to+6.5),and high(^(206) Pb/^(204)Pb)i,(^(207) Pb/^(204)Pb)i,(^(208) Pb/^(204)Pb)iand ratios(18.522 to 18.561,15.641 to 15.645 and 38.679 to 38.730,respectively)suggest that the Nadun NEABs are more enriched than those of the island arc basalts(IABs)in the *** slightly enriched radiogenic isotopes for the Nadun NEABs indicate that the subducting sediments play an important role in the ***,their high Nb,Ti,and Cu contents indicate that the source mantle wedge was metasomatized by slab *** Nadun NEAB and other coeval magmatic rocks in the Duolong mineral district,including adakite,OIB-like basalt,MORB-type basalt,A-type rhyolite,and common IAB,are typical rock assemblages of ridge *** infer that the Duolong mineral district were formed by ridge subduction in the Early Cretaceous.

关键词： Tibet Duolong porphyry Cu-Au deposit Nb-enriched arc basalt Tethys ocean Ridge subduction

Sequence Divergence of Microsatellites and Phylogeny Analysis in Tetraploid Cotton Species and Their Putative Diploid Ancestors

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2005年第12期47卷 1418-1430页

作者： Wang-Zhen GUO Dong FANG Wen-Duo yu tian-Zhen zhang State Key Laboratory of Crop Genetics and Germplasm Enhancement Cotton Research Institute Nanjing Agricultural University Nanjing 210095 China

To determine the level of microsatellite sequence differences and to use the information to construct a phylogenetic relationship for cultivated tetraploid cotton （Gossypium spp.） species and their putative diploid ancestors, 10 genome-derived microsatellite primer pairs were used to amplify eight species, including two tetraploid and six diploid species, in Gossypium. A total of 92 unique amplicons were resolved using polyacrylamide gel electrophoresis. Each amplicon was cloned, sequenced, and analyzed using standard phylogenetic software. Allelic diversities were caused mostly by changes in the number of simple sequence repeat （SSR） motif repeats and only a small proportion resulted from interruption of the SSR motif within the locus for the same genome. The frequency of base substitutions was 0.5%-1.0% in different genomes, with only few indels found. Based on the combined 10 SSR flanking sequence data, the homology of A-genome diploid species averaged 98.9%, even though most of the amplicons were of the same size, and the sequence homology between G. gossypioides （Ulbr.） Standl. and three other D-genome species （G. raimondii Ulbr., G. davidsonii Kell., and G. thurberi Tod.） was 98.5%, 98.6%, and 98.5%, respectively. Phylogenetic trees of the two allotetraploid species and their putative diploid progenitors showed that homoelogous sequences from the A- and D-subgenome were still present in the polyploid subgenomes and they evolved independently. Meanwhile, homoelogous sequence interaction that duplicated loci in the polyploid subgenomes became phylogenetic sisters was also found in the evolutionary history of tetraploid cotton species. The results of the present study suggest that evaluation of SSR variation at the sequence level can be effective in exploring the evolutionary relationships among Gossypuim species.

关键词： diploid Gossypium microsatellite phylogenetic tree simple sequence repeat (SSR) tetraploid.

Scutellaria barbata attenuates diabetic retinopathy by preventing retinal inflammation and the decreased expression of tight junction protein

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2017年第6期10卷 870-877页

作者： Xi-yu Mei Ling-yu Zhou tian-yu zhang Bin Lu Li-Li Ji The MOE Key Laboratory for Standardization of Chinese Medicines Shanghai Key Laboratory of Complex Prescription Institute of Chinese Materia Medica Shanghai University of Traditional Chinese Medicine Shanghai 201203 China

AIM： To observe the attenuation of ethanol extract of Herba Scutellaria barbata （SE） against diabetic retinopathy （DR） and its engaged mechanism. METHODS： C57BL/6J mice were intraperitoneally injected with streptozotocin （STZ, 55 mg/kg） for 5 consecutive days to induce diabetes, The diabetic mice were orally given with SE （100, 200 mg/kg） for lmo at lmo after STZ injection. Blood-retinal barrier （BRB） breakdown was detected by using Evans blue permeation assay. Real-time polymerase chain reaction （RT-PCR）, Western blot and immunofiuorescence staining were used to detect mRNA and protein expression. Enzyme-linked immunosorbent assay （ELISA） was used to detect serum contents of tumor necrosis factor-e （TNF-a） and interleukin （IL）-II. RESULTS： SE （100, 200 mg/kg） reversed the breakdown of BRB in STZ-induced diabetic mice. The decreased expression of retinal claudin-1 and claudin-19, which are both tight junction （T J） proteins, was reversed by SE. SE decreased the increased serum contents and retinal mRNA expression of TNF-a and IL-113. SE also decreased the increased retinal expression of intercellular cell adhesion molecule-1 （ICAM-1）. SE reduced the increased phosphorylation of nuclear factor kappa B （NFKB） p65 and its subsequent nuclear translocation in retinas from STZ- induced diabetic mice. Results of Western blot and retinal immunofluorescence staining of ionized calcium-binding adapter molecule 1 （Ibal） demonstrated that SE abrogated the activation of microglia cells in STZ-induced diabetic mice. CONCLUSION： SE attenuates the development of DR by inhibiting retinal inflammation and restoring the decreased expression of TJ proteins including claudin-1 and claudin-19.

关键词： scutellaria barbata diabetic retinopathy tightjunction inflammation nuclear factor kappa B microglia

Diversity analysis of soil dematiaceous hyphomycetes from the Yellow River source area:Ⅰ

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第10期9卷 829-834页

作者： Hao-qin PAN Jin-feng yu yue-ming WU tian-yu zhang Hong-feng WANG Mycological Laboratory Department of PlantPathology Shandong Agricultural University Tai＇an 271018 China

Twenty-four soil samples of eight ecosystem-types around the Yellow River source area were investigated for the number and specific composition of soil dematiaceous hyphomycetes by dilution plate technique. And then the co-relationship between genus species of soil dematiaceous hyphomycetes and ecosystem-types was analyzed. The results show that the amount and species distribution of soil dematiaceous hyphomycetes had an obvious variability in different ecosystem-types, and that the dominant genus species varied in the eight ecosystem-types studied, with Cladosporium being the dominant genus in seven of the eight ecosystem-types except wetland. The index of species diversity varied in different ecosystem-types. The niche breadth analysis showed that Cladosporium had the highest niche breadth and distributed in all ecosystem-types, while the genera with a narrow niche breadth distributed only in a few ecosystem-types. The results of niche overlap index analysis indicated that Stachybotrys and Torula, Doratomyces and Scolecobasidium, Cladosporium and Chrysosporium had a higher niche overlap, whereas Arthrinium and Gliomastix, Phialophora and Doratomyces, Oidiodendron and Ulocladium had no niche overlap.

关键词： Yellow River source area Ecosystems Fungal species diversity Soil dematiaceous hyphomycetes Niche breadth Niche overlap

Scutellarein alleviates the dysfunction of inner blood-retinal-barrier initiated by hyperglycemia-stimulated microglia cells

在线全文

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2020年第10期13卷 1538-1545页

作者： Han Li Xi-yu Mei Meng-Na Wang tian-yu zhang yue zhang Bin Lu yu-Chen Sheng The MOE Key Laboratory for Standardization of Chinese Medicines Shanghai Key Laboratory of Compound Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese MedicinesInstitute of Chinese Materia MedicaShanghai University of Traditional Chinese MedicineShanghai 201203China Center for Drug Safety Evaluation and Research Innovation Research Institute of Traditional Chinese MedicineShanghai University of Traditional Chinese MedicineShanghai 201203China

AIM:To investigate the alleviation of scutellarein(SN)against inner blood-retinal-barrier(iBRB)dysfunction in microglia cells stimulated by hyperglycemia and to elucidate the engaged ***:Microglia BV2 cells were stimulated by using 25 mmol/L *** same concentration of mannitol(25 mmol/L)was applied as an isotonic ***-time PCR,Western-blot assay and immunofluorescence staining assay was *** dysfunction of iBRB in vitro was detected by using transendothelial electrical resistance(TEER)***,the leakage of fluorescein isothiocyanate(FITC)-conjugated dextran(70 kDa)was ***:SN abrogated microglia BV2 cells activation and reduced the phosphorylated activation of extracellular signal-regulated protein kinase(ERK)1/*** also decreased the transcriptional activation of nuclear factorκB(NFκB)and the elevated expression of tumor necrosis factorα(TNFα),interleukin(IL)-6 and IL-1βin BV2 cells treated with D-glucose(25 mmol/L).SN attenuated iBRB dysfunction in human retinal endothelial cells(HRECs)or choroid-retinal endothelial RF/6 A cells when those cells were treated with TNFα,IL-1βor IL-6,or co-cultured with microglia cells stimulated by ***,SN restored the decreased protein expression of tight junctions(TJs)in TNFα-treated HRECs and RF/6 A ***:SN not only alleviate iBRB dysfunction via directly inhibiting retinal endothelial injury caused by TNFα,IL-1βor IL-6,but also reduce the release of TNFα,IL-1βand IL-6 from microglia cells by abrogating hyperglycemia-mediated the activation of microglia cells.

关键词： scutellarein blood-retinal-barrier tight junctions inflammation tumor necrosis factorα