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Highly Improved Creep Resistance in Polypropylene Through Thermally Reduced Graphene Oxide and Its Creep Lifetime Prediction

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Chinese Journal of Polymer Science 2024年第2期42卷 256-266,I0010页

作者： Can-Can Zhang jun-Long Yang Ya-jiang Huang Guang-xian Li College of Polymer Science and Engineering State Key Laboratory of Polymer Materials Engineering of ChinaSichuan UniversityChengdu610065China

Polypropylene(PP) exhibits suboptimal creep resistance due to the presence of methyl groups on its main chain, leading to irregular chain segment distribution, diminished inter-chain interaction, and crystallinity. This structural feature causes chain slippage in PP under stress,significantly constraining its service lifetime. In this study, thermally reduced graphene oxide(TrGO) nanosheets were incorporated into the PP matrix, yielding a nanocomposite with exceptional creep resistance performance. Results demonstrated that at a stress of 25 MPa, a 2.0 wt% TrGO content could enhance the creep failure lifetime of PP by 21.5 times compared to neat PP. Rheology, transmission electron microscopy(TEM),and scanning electron microscopy(SEM) characterization techniques were employed to analyze the mechanism of TrGO's influence on PP's creep behavior. It was observed that when TrGO content exceeded 1.0 wt%, an effective particle network structure formed within the PP matrix. This homogeneously dispersed TrGO-formed particle network structure restricted the migration and rearrangement of PP molecular chains, enabling prolonged stress resistance without structural failure. By combining the time-strain superposition method with the critical failure strain as a criterion, generalized creep compliance curves for PP and its composites were established, facilitating the prediction of material creep failure lifetimes, with a strong agreement between experimental and predicted lifetime values. This research proposes a novel strategy aimed at developing polypropylene materials and products with enhanced long-term stability and durability, thus extending service life, reducing failure risk, and broadening their potential across various application domains.

关键词： Thermally reduced graphene oxide Polypropylene Creep failure and lifetime prediction

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Lanostane-Type Triterpenoids from Scilla scilloides and Structure Revision of Drimiopsin D

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Natural Products and Bioprospecting 2015年第5期5卷 263-270页

作者： Fu-Cai Ren Li-Xia Wang Qin Yu xian-jun jiang Fei Wang BioBioPha Co. Ltd.Kunming 650201People’s Republic of China

Two hitherto unknown lanostane-type triterpenoids,namely scillascillol(1)and scillascillone(2),and a hitherto unknown norlanostane-triterpene glycoside,namely scillascilloside B-1(3),were isolated from the ethanol extract of the whole plants of Scilla *** structures were elucidated on the basis of extensive spectroscopic *** addition,the structure of drimiopsin D(6a)has been revised as 2,5-dimethoxy-8-methyl-1,3,6-trihydroxyxanthone(6)by reanalysis of the spectroscopic data.

关键词： Scilla scilloides Lanostane Scillascillol Scillascillone Structure revision

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FPGA-based position reconstruction method for neutron beam flux spatial distribution measurement in BNCT

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Nuclear Science and Techniques 2024年第3期35卷 96-108页

作者： Wei jiang Ping Cao Yi-Ming Wu xian-Ke Liu Zhu-jun Fang Zhi-Yong Zhang Bin Shi jun Chen State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026China Department of Modern Physics University of Science and Technology of ChinaHefei 230026China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230026China National Key Laboratory for Metrology and Calibration Techniques China Institute of Atomic EnergyBeijing 102413China

A new measurement method for the spatial distribution of neutron beam flux in boron neutron capture therapy(BNCT)is being developed based on the two-dimensional Micromegas *** address the issue of long processing times in traditional offline position reconstruction methods,this paper proposes a field programmable gate array based online position reconstruction method utilizing the micro-time projection chamber *** method encapsulates key technical aspects:a self-adaptive serial link technique built upon the dynamical adjustment of the delay chain length,fast sorting,a coordinate-matching technique based on the mapping between signal timestamps and random access memory(RAM)addresses,and a precise start point-merging technique utilizing a circular combined *** performance test of the selfadaptive serial link shows that the bit error rate of the link is better than 10-12 at a confidence level of 99%,ensuring reliable data *** experiment utilizing the readout electronics and Micromegas detector shows a spatial resolution of approximately 1.4 mm,surpassing the current method’s resolution level of 5 *** beam experiment confirms that the readout electronics system can obtain the flux spatial distribution of neutron beams online,thus validating the feasibility of the position reconstruction *** online position reconstruction method avoids traditional methods,such as bubble sorting and traversal searching,simplifies the design of the logic firmware,and reduces the time complexity from O(n2)to O(n).This study contributes to the advancement in measuring neutron beam flux for BNCT.

关键词： Position reconstruction FPGA Readout electronics Neutron flux spatial distribution

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New Taxane Diterpenoids from Taxus yunnanensis

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Natural Products and Bioprospecting 2014年第1期4卷 47-51页

作者： Ping Hai Shi-Zhen Wen Yan Li Yuan Gao xian-jun jiang Fei Wang BioBioPha Co. Ltd.Kunming 650201China State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China

Three hitherto unknown taxane diterpenoids,namely baccatin Ⅷ(1),baccatin Ⅸ(2),and baccatin Ⅹ(3),along with 10 known analogues were isolated from an ethanolic extract of the twigs and leaves of Taxus *** new structures were characterized based on extensive spectroscopic *** 1 and 2 were tested for their in vitro cytotoxicity against five human tumor cell lines,and 1 exhibited inhibitory effects on HL-60 and MCF-7,with IC_(50) values of 3.44 and 9.67 μM,respectively.

关键词： Taxus yunnanensis Taxane Baccatin Cytotoxicity

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Intermediate-mass black holes in Green pea galaxies(IMBH-GP) I:A candidate sample from LAMOST and SDSS

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Science China(Physics,Mechanics & Astronomy) 2024年第10期Mechanics & Astronomy) .卷 151-165页

作者： Ruqiu Lin Zhen-Ya Zheng Fang-Ting Yuan jun-xian Wang Chunyan jiang Ning jiang Lingzhi Wang Linhua jiang xiang Ji Shuairu Zhu Xiaodan Fu Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical ObservatoryChinese Academy of Sciences School of Astronomy and Space Sciences University of Chinese Academy of Sciences CAS Key Laboratory for Research in Galaxies and Cosmology Department of AstronomyUniversity of Science and Technology of China Chinese Academy of Sciences South America Center for Astronomy (CASSACA) National Astronomical ObservatoriesChinese Academy of Sciences CAS Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of Sciences Kavli Institute for Astronomy and Astrophysics Peking University Department of Astronomy School of PhysicsPeking University

The scaling relation of central massive black holes（MBHs） and their host galaxies is well-studied for supermassive BHs(SMBHs,MBH≥10～6M⊙).However,this relation has large uncertainties in the mass range of the intermediate-mass BHs(IMBHs,MBH～10～3-10～6M⊙).Since Green pea（GP） galaxies are luminous compact dwarf galaxies,which may be likely to host less massive SMBHs or even IMBHs,we systematically search for MBHs in a large sample of 2190 GP galaxies at z<0.4,selected from LAMOST and SDSS spectroscopic ***,we report a newly discovered sample of 59 MBH candidates with broad Hα *** sample has a median stellar mass of 108.83±0.11M⊙and hosts MBHs with single-epoch virial masses ranging from MBH～104.7to 108.5M⊙(median 105.85±0.64M⊙).Among the 59 MBH candidates,36 have black hole masses MBH≤10～6M⊙（IMBH candidates）,one of which even has MBH■10～5M⊙.We find that the MBH-M*relation of our MBH sample is consistent with the MBH-Mbulgerelation for SMBHs,while is above the MBH-M*relation for MBHs in dwarf galaxies in the same mass ***,we show that 25 MBH candidates,including 4 IMBH candidates,have additional evidence of black hole activities,assessed through various methods such as the broad-line width,BPT diagram,mid-infrared color,X-ray luminosity,and radio *** studies show that it is very promising to find IMBHs in GP galaxies,and the BH sample so obtained enables us to probe the connection between the MBHs and compact dwarf galaxies in the low-redshift Universe.

关键词： SMBHs IMBHs Green pea galaxies compact dwarf galaxies

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Differences and identification on multi-time hydrocarbon generation of carboniferous-permian coaly source rocks in the Huanghua Depression,Bohai Bay Basin

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Petroleum Science 2024年第2期21卷 765-776页

作者： Jin-jun Xu xian-Gang Cheng Shu-Nan Peng jun-Cai jiang Qi-Long Wu Da Lou Fu-Qi Cheng La-Mei Lin National Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao 266580ShandongChina PetroChina Dagang Oilfield Company Tianjin300280China

Coal is a solid combustible mineral,and coal-bearing strata have important hydrocarbon generation potential and contribute to more than 12%of the global hydrocarbon ***,the deposition and hydrocarbon evolution process of ancient coal-bearing strata is characterized by multiple geological times,leading to obvious distinctions in their hydrocarbon generation potential,geological processes,and production,which affect the evaluation and exploration of hydrocarbon resources derived from coaly source rocks *** study aimed to identify the differences on oil-generated parent macerals and the production of oil generated from different coaly source rocks and through different oil generation *** with the analysis of previous tectonic burial history and hydrocarbon generation history,high-temperature and high-pressure thermal simulation experiments,organic geochemistry,and organic petrology were performed on the Carboniferous-Permian(C-P)coaly source rocks in the Huanghua Depression,Bohai Bay *** oil-generated parent macerals of coal's secondary oil generation process(SOGP)were mainly hydrogen-rich collotelinite,collodetrinite,sporinite,and cutinite,while the oil-generated parent macerals of tertiary oil generation process(TOGP)were the remaining small amount of hydrogen-rich collotelinite,sporinite,and cutinite,as well as dispersed soluble organic matter and unexhausted residual *** with coal,the oil-generated parent macerals of coaly shale SOGP were mostly sporinite and *** part of hydrogen-poor vitrinite,lacking hydrocarbon-rich macerals,and macerals of the TOGP,in addition to some remaining cutinite and a small amount of crude oil and bitumen from SOGP contributed to the oil *** results indicated that the changes in oil yield had a good junction between SOGP and TOGP,both coal and coaly shale had higher SOGP aborted oil yield than TOGP starting yield,and coaly shale TOGP peak oil yield was low

关键词： Thermal simulation Multi-time oil generation processes Coaly source rock Carboniferous-permian Huanghua Depression

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Aristolane‑type Sesquiterpenoids from Nardostachys chinensis and Revised Structure of Aristolanhydride

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Natural Products and Bioprospecting 2019年第2期9卷 149-155页

作者： Li-Xia Wang xian-jun jiang xiang-Mei Li Mei-Fen Mao Guo-Zhu Wei Fei Wang BioBioPha Co. Ltd.Kunming 650201People’s Republic of China Reference Substances Sub-center National Engineering Research Center for Modernization of Traditional Chinese MedicineKunming 650201People’s Republic of China

Four hitherto unknown aristolane-type sesquiterpenes,including one novel 8,9-secoaristolane,namely secoaristolenedioic acid(1),two aristolone derivatives,namely 1α,2β-dihydroxyaristolone(2),9-epidebilon(3),and one rare aristolane-chalcone hybrid,namely 3′-hydroxynardoaristolone A(4)were isolated from the ethanol extract of the roots and rhizomes of Nardostachys *** structures were elucidated on the basis of extensive spectroscopic *** addition,the structure of aristolanhydride,recently isolated from the same species,was corrected by reanalysis of the published NMR data.

关键词： Nardostachys chinensis Aristolane Secoaristolane Aristolane-chalcone hybrid Structural revision

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Pterocarpadiols A–D, Rare 6a,11b-Dihydroxypterocarpans from Derris robusta

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Natural Products and Bioprospecting 2015年第6期5卷 287-291页

作者： xiang-Mei Li Mei-Fen Mao Fu-Cai Ren xian-jun jiang Ping Hai Fei Wang BioBioPha Co. Ltd.Kunming 650201People’s Republic of China

Four hitherto unknown 6a,11b-dihydroxypterocarpans,namely pterocarpadiols A–D(1–4),were isolated from the ethanol extract of the twigs and leaves of Derris *** structures were elucidated on the basis of extensive spectroscopic *** A–D are a kind of very rare 6a,11b-dihydroxypterocarpans,and their presence as markers may be helpful in chemotaxonomical classification.

关键词： Derris robusta 6a,11b-Dihydroxypterocarpan Pterocarpadiol

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Prenylated Coumarins from Heracleum stenopterum,Peucedanum praeruptorum,Clausena lansium,and Murraya paniculata

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Natural Products and Bioprospecting 2016年第5期6卷 233-237页

作者： xiang-Mei Li xian-jun jiang Ku Yang Li-Xia Wang Shi-Zhen Wen Fei Wang BioBioPha Co. Ltd.Kunming 650201People’s Republic of China

Four hitherto unknown prenylated coumarins,namely 600-O-b-D-apiofuranosylapterin(1),40-O-isobutyroylpeguangxienin(2),6-(3-methyl-2-oxobutyroyl)-7-methoxycoumarin(3),and 6-hydroxycoumurrayin(4),were isolated from the ethanol extract of Heracleum stenopterum,Peucedanum praeruptorum,Clausena lansium,and Murraya paniculata,*** chemical structures were established on the basis of extensive spectroscopic ***pound 2 exhibited in vitro cytotoxic activity against five human cancer cell lines(HL-60,A-549,SMMC-7721,MCF-7,and SW-480)with IC50 values ranging from 15.9 to 23.2μM.

关键词： Heracleum stenopterum Peucedanum praeruptorum Clausena lansium Murraya paniculata Prenylated coumarin Cytotoxicity

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Level pinning of anti-PT-symmetric circuits for efficient wireless power transfer

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National Science Review 2024年第1期11卷 215-224页

作者： Zhiwei Guo Fengqing Yang Haiyan Zhang xian Wu Qiong Wu Kejia Zhu jun jiang Haitao jiang Yaping Yang Yunhui Li Hong Chen MOE Key Laboratory of Advanced Micro-Structured Materials School of Physics Sciences and Engineering Tongji University Department of Electrical Engineering Tongji University School of Automotive Studies Tongji University

Wireless power transfer(WPT) technology based on magnetic resonance(a basic physical phenomenon)can directly transfer energy from the source to the load without wires and other physical contacts, and has been successfully applied to implantable medical devices, electric vehicles, robotic arms and other ***, due to the frequency splitting of near-field coupling, the resonant WPT system has some unique limitations, such as poor transmission stability and low efficiency. Here, we propose anti-resonance with level pinning for high-performance WPT. By introducing the anti-resonance mode into the basic WPT platform, we uncover the competition between dissipative coupling and coherent coupling to achieve novel level pinning, and construct an effective anti-parity-time(anti-PT)-symmetric non-Hermitian system that is superior to previous PT-symmetric WPT schemes. On the one hand, the eigenvalue of the anti-PT-symmetric system at resonance frequency is always pure real in both strong and weak coupling regions, and can be used to overcome the transmission efficiency decrease caused by weak coupling, as brought about by, for example, a large size ratio of the transmitter to receiver, or a long transmission *** the other hand, due to the level pinning effect of the two kinds of coupling mechanisms, the working frequency of the system is guaranteed to be locked, so frequency tracking is not required when the position and size of the receiver change. Even if the system deviates from the matching condition, an efficient WPT can be realized, thereby demonstrating the robustness of the level pinning. The experimental results show that when the size ratio of the transmitter coil to the receiver coil is 4.29(which is in the weak coupling region), the transfer efficiency of the anti-PT-symmetric system is nearly 4.3(3.2) times higher than that of the PT-symmetric system when the matching conditions are satisfied(deviated). With the miniaturization and integration of d

关键词： non-Hermitian system wireless power transfer anti-PT-symmetric circuits synthetic dimension metamaterials

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