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A New Triterpenoid Spaonin Isolated from the Seeds of Aesculus assamica Griff

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Chinese Chemical Letters 2006年第2期17卷 211-214页

作者： Hong Wei liU xin Sheng YAO Nai li WANG Guo Ping CAI life Scinece Division Graduate School at Shenzhen Tsinghua University Shenzhen 518055 Key lab for Research and Development of New Drugs Shenzhen 518055 School of Traditional Chinese Matcria Medica Shcnyang Pharmaceutical University Shenyang 110016

A new triterpenoid saponin, 21 β-angeloylprotoaescigenin-3β-O- [α-L-rhamnopyranosyl- （1-3）]β-D-glucopyranosiduronic acid 1, was isolated from the seeds of Aesculus assamica Griff. Its structure was elucidated on... 详细信息

关键词： Aesculus assamica triterpenoid saponin Pyricularia oryzae.

The shift in the abundance of two Stipa species in response to land use change is associated with their divergent reproductive strategies

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Journal of Plant Ecology 2019年第4期12卷 722-729页

作者： Xiaoshuai Wang Frank Yonghong li Yuanheng li xin Song Xudong Guo Xiangyang Hou Taogetao Baoyin Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolian Plateau&Inner Mongolia Key Laboratory of Grassland Ecology School of Ecology and EnvironmentInner Mongolia UniversityHohhot 010021China Grassland Research Institute of the Chinese Academy of Agricultural Sciences Hohhot 010020China

Aims The divergent changes of plant species under land use changes are key mechanisms underlying vegetation *** grandis steppe and Stipa krylovii steppe are two plant commu-nities widely distributed on the Mongolian *** have been speculated to be able to succeed into each other under different land use types and intensities based on the observa-tions on their presence and abundance at the sites with dif-ferent land use ***,no direct evidence,neither the underlying mechanisms,have been reported for this ***,we verified this speculation and explored the underlying mechanisms in the typical steppe region of Inner *** We investigated the abundance and reproductive behavior of ***-lovii and *** under different land use types and *** used 18 grassland paddocks to run a 6-year experiment with 6 management treatments(T0-unused,T1-grazing monthly in plant growing season,T2,T4,T6-grazing in different months in plant growing season,and T8-mowing)replicated three *** measured the relative density and cover of *** and *** using line sampling method and examined their number and bio-mass of vegetative and reproductive tillers using quadrat method in each paddock after treatments for 4 and 6 *** also de-termined these plant attributes in 14 pairs of heavily versus lightly used grassland plots in a wide area(150 km×200 km)of the typical steppe *** Findings *** largely and mowing moderately decreased the density ratio and coverage ratio of *** to *** in grasslands(P<0.05),and the differences in these ratios between grazed and unused grasslands increased with ***,but not mowing,significantly enhanced the relative density(N_(rep)=reproductive tiller number/total tiller number)of,and biomass allocation(B_(rep)=reproductive tiller biomass/total bio-mass)to,reproductive tillers of ***(P<0.05),but not *** grazing enhancement t

关键词： reproductive tiller vegetative tiller succession grazing mowing

High-conductivity free-standing li_(6)PS_(5)Cl/poly(vinylidene difluoride)composite solid electrolyte membranes for lithium-ion batteries

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Journal of Materiomics 2020年第1期6卷 70-76页

作者： Shuo Wang Xue Zhang Sijie liu Chengzhou xin Chuanjiao Xue Felix Richter liangliang li lizhen Fan Yuanhua lin Yang Shen Jurgen Janek Ce-Wen Nan State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing100084China Institute of Physical Chemistry&Center for Materials Research Justus-Liebig-University GiessenHeinrich-Buff-Ring 17D-35392GiessenGermany Institute of Advanced Materials and Technology University of Science and Technology BeijingBeijing100083China

Bulk-type all-solid-state batteries(ASSBs)using sulfide solid electrolyte are considered as a promising alternative to commercial lithium-ion batteries owing to their high energy density and ***,cell energy density is often comparatively low due to use of a thick solid electrolyte separator and a lithium alloy as *** achieving high-performance ASSBs,creating a thin free-standing electrolyte with high-conductivity and good cycling stability against lithium anode is *** this work,we present li_(6)PS_(5)Cl/poly(vinylidene difluoride)(LPSCl/PVDF)composite electrolytes prepared by a slurry *** influence of the PVDF content on the microstructure,morphology,ionic conductivity and activation energy of the LPSCl/PVDF electrolytes is systematically ***-standing LPSCl/PVDF membranes with a thickness of 100-120 mm and a high ionic conductivity of about 1·10^(-3) S cm^(-1) at 25℃ are *** adding PVDF to the LPSCl electrolyte,the cycling stability of the LPSCl electrolyte against lithium metal improves ***,LPSCl/PVDF composite electrolytes are promising candidates to be used in ASSBs.

关键词： Composite solid electrolyte li_(6)PS_(5)Cl Poly(vinylidene difluoride)

Synthesis of Novel Thiol Taxoid Based on the 7,10-Di-(2,2,2-trichloroethyl-oxycarbonyl)-10-deacetylbaccatin Ⅲ and (4R,5S)-2,4-Diphenyl-2-oxazoline-5-carboxylic acid: (2'R,3'R)-10-Deacetyl- 2'-deoxy-mercaptopaclitaxel

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有机化学 2004年第Z1期24卷 57-58页

作者： XU,li QI,xin ZHOU,Zhi-Ping Information College of Science and Technology Nanjing Forestry University Nanjing 210037 School of Chemical Engineering Dalian University of Technology Dalian 116012 College of Chemistry and Chemical Engineering Nanjing University Nanjing 210093

　　The complex natural product paclitaxel (TaxolR) 1, first isolated from Taxus brevifolia, and its semisynthetic analog,docetaxel 2, represent a large family of taxane diterpenoids, which revealed excellent clinical activity against ovarian and breast cancers, and showed promising results in the treatment of other cancers.[1] Extensive studies on the structure activity relationship (SAR) have been explored. It is already well known that a free hydroxyl group at the C-2' position on the C-13 side chain is crucial for microtubule binding[2] and may act as a hydrogen bond donor.……

关键词： natural product hydroxyl group hydrogen bond side chain

Electric Thrusters Redundancy Configuration Strategy Study for All Electric Propulsion Platform Station-Keeping

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Journal of Harbin Institute of Technology(New Series) 2018年第3期25卷 55-61页

作者： Min Wang Qiang li xin’gang liang School of Astronautics Beihang UniversityBeijing 100191China China Academy of Space Technology Beijing 100094China

Electric propulsion is used for all electric propulsion satellites to perform the orbit transfer,attitude control and station-keeping tasks. Generally electric propulsion subsystem contains 4 thrusters. But if one thruster fails in the beginning of satellite lifetime,other thrusters will undertake all the firing tasks. The firing time will be 2 to 3 times of thrusters without failure. Thus it may go beyond the allow ed lifetime of thruster. This paper puts forward two thruster redundancy configuration solutions with 6 thrusters to solve this problem. Two layout configurations and their corresponding station-keeping strategies are simulated and compared. The results show that the maximum firing time of both layout configurations can meet the lifetime limitation. This solution is a good reference for all electric propulsion satellites design.

关键词： all electric propulsion satellite station-keeping electric thrusters configuration electric thruster layout failure redundancy

Potential Autonomous Selfing in Gesneria citrina (Gesneriaceae),a Specialized Hummingbird Pollinated Species with Variable Expression of Herkogamy

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Journal of Integrative Plant Biology 2009年第10期51卷 973-978页

作者： xin-Sheng Chen Silvana Marten-Rodriguez Qing-Jun li Charles B. Fenster Xishuangbanna Tropical Botanical Garden the Chinese Academy of Sciences Mengla 666303 China Department of Biology University of Maryland College Park MD 20742 USA Herbario de la Universidad de Costa Rica Escuela de Biologia Ciudad Universitaria Rodrigo Facio San Pedro San Jose Costa Rica

Species with mixed mating systems often demonstrate variable expression of breeding system characteristics and thus represent the opportunity to understand the factors and mechanisms that promote both outcrossed and selfed seed production. Here, we investigate variation in levels of herkogamy （variation in stigma-anther separation distance） in a Puerto Rican population of hummingbird pollinated Gesneria citrina Urban. There is significant variation in herkogamy levels among individuals of this species and stigma-anther separation is negatively associated with the ability to set fruits and seeds in the absence of pollinators. The variation in levels of herkogamy may represent a mechanism to ensure the production of some self-fertilized progeny in the absence of hummingbird pollinators. We also describe a novel breeding system in G. citrina, where stamens elongate over time to reach stigma height, but stamen elongation is accelerated by pollination. These results suggest that once the flowers are pollinated, stamen elongation may favor increased pollen removal and siring success, while the reduction in stigma-anther distance no longer imposes the risk of interference between male and female functions. We discuss our findings of breeding system variation in the context of pollination system evolution in an island setting （Antillean islands）.

关键词： mixed-mating pollen limitation pollination system Puerto Rico reproductive assurance stigma-anther separation.

NUMERICAL INVESTIGATION ON MUD BED-GENERATION AND IMPACTING A WALL ALONG A SLOPE

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Journal of Hydrodynamics 2002年第2期14卷 7-11页

作者： Yue, Peng-Tao Xu, Sheng-li liu, Da-You Duan, xin-Ping Univ. of Sci. and Technol. of China Hefei 230026 China Inst. of Mech. Chinese Acad. of Sci. Beijing 100080 China

In this paper mud was treated as the Bingham fluid. In staggered grids, two-dimensional incompressible Navier-Stokes equations for non-Newtonian fluid was solved by the MAC method. Numerical simulations were conducted on mud bed-generating phenomenon and mud impacting a wall along a slope. The distributions of free surface, pressure and velocity of mud and water were obtained. The results indicate that the computed layer thickness of mud bed almost equals the theoretically predicted value. Because of the differences in constitutive relationship, the distributions of free surface are different for water and mud. The distortion of water free surface is much more complicated.

关键词： Computer simulation Incompressible flow Navier Stokes equations Non Newtonian liquids Slope stability Two dimensional

Novel P2-type layered medium-entropy ceramics oxide as cathode material for sodium-ion batteries

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Journal of Advanced Ceramics 2022年第1期11卷 158-171页

作者： Shengxue YAN shaohua LUO liu YANG Jian FENG Pengwei li Qing WANG Yahui ZHANG xin liU School of Materials Science and Engineering Northeastern UniversityShenyang 110819China Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province School of Resources and MaterialsNortheastern University at QinhuangdaoQinhuangdao 066004China School of Resources and Materials Northeastern University at QinhuangdaoQinhuangdao 066004China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819China

High-entropy oxides(HEOs)and medium-entropy oxides(MEOs)are new types of single-phase solid solution *** have rarely been reported as positive electrode material for sodium-ion batteries(SIBs).In this study,we first proposed the concept of the application of MEOs in SIBs.P2-type 3-cation oxide Na_(2/3)Ni_(1/3)Mn_(1/3)Fe_(1/3)O_(2)(NaNMF)and 4-cation oxide Na_(2/3)Ni_(1/3)Mn_(1/3)Fe_(1/3-x)Al_(x)O_(2)(NaNMFA)were prepared using the solid-state method,rather than the doping *** addition,the importance of the concept of entropy stabilization in material performance and battery cycling was demonstrated by testing 3-cation(NaNMF)and 4-cation(NaNMFA)oxides in the same ***,NaNMFA can provide a reversible capacity of about 125.6 mAh-g”1 in the voltage range of 2-4.2 V,and has enhanced cycle *** capacity and decay law of the MEO batteries indicate that the configurational entropy(1.28 R(NaNMFA)>1.10 R(NaNMF))of the cationic system,is the main factor affecting the structural and cycle stability of the electrode *** work emphasizes that the rational design of MEOs with novel structures and different electrochemically active elements may be the strategy for exploring high-performance SIB cathode materials in next-generation energy storage devices.

关键词： cathode materials medium-entropy oxide(MEO) configuration entropy electrochemical performance sodium-ion batteries(SIBs)

Injectable silk/hydroxyapatite nanocomposite hydrogels with vascularization capacity for bone regeneration

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Journal of Materials Science & Technology 2021年第4期63卷 172-181页

作者： Keke Wang Weinan Cheng Zhaozhao Ding Gang Xu xin Zheng Meirong li Guozhong Lu Qiang Lu College of Chemistry Chemical Engineering and Materials Science&Collaborative Innovation Center of Suzhou Nano Science and TechnologySoochow UniversitySuzhou 215123China Department of Burns and Plastic Surgery The Affiliated Hospital of Jiangnan UniversityWuxi 214041China Department of Orthopedics The First Affiliated Hospital of Xiamen UniversityXiamen 361000China Department of Orthopedics The Second Affiliated Hospital of Soochow UniversitySuzhou 215000China Institute of Basic Medical Science Wound Healing and Cell Biology LaboratoryChinese PLA General HospitalBeijing 100853China

Localized and sustained osteogenic-angiogenic stimulation to bone defects is critical for effective bone ***,desferrioxamine(DFO)was loaded on silk fibroin nanofibers and blended with hydroxyapatite nanorods(HA),forming injectable DFO-loaded silk fibroin-HA nanocomposite *** composite hydrogels remained homogeneous distribution of HA with high ratio(60%)and also higher stiffness than that of pure silk fibroin nanofiber hydrogels,which provided stable osteogenic stimulation niches for tissue *** the scarify of injectability,the hydrogels achieved slow delivery of DFO for above 60 days,resulting in suitable angiogenesis in vitro and in vivo and better osteogenesis than DFO-free *** to previous injectable silk fibroin-HA hydrogels,the introduction of vascularization capacity further stimulated the osteogenic differentiation of stem cells and accelerated new bone *** and better bone healing were detected at defect sites after the injection of DFO-loaded nanocomposite hydrogels,indicating the effective synergistic effect of osteogenic and angiogenic *** work provides a simple and effective strategy of introducing angiogenic cues to bone *** believe that the injectable nanocomposite hydrogels are suitable for the regeneration of bone tissues.

关键词： hydrogel loaded synergistic