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Near-Earth Asteroids as the Parents of the δ-Cancrid Meteoroid Stream

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Research in Astronomy and Astrophysics 2024年第12期24卷 13-25页

作者： G.I.Kokhirova M.Zhang x.-G.li A.I.Zhonmuhammadi x.liu Institute of Astrophysics National Academy of Sciences of Tajikistan x.njiang Astronomical Observatory Chinese Academy of Sciences Key Laboratory for Radio Astronomy Chinese Academy of Sciences x.njiang Key Laboratory of Radio Astrophysics University of Chinese Academy of Sciences

The δ-Cancrid meteoroid stream forms four active meteor showers which are observable on the Earth annually during January–February and August–September. The stream's definite parent comet has not been established. We performed a search for near-Earth asteroids(NEAs) associated with this stream. We have followed the backward evolution of the orbital elements of a sample of NEAs and found their orbits at the Earth-crossing positions. Using these orbits, we calculated the theoretical parameters of meteor showers associated with the considered NEAs. We carried out our search for observable active showers that match theoretically predicted ones with published data,and the result turned out that the predicted meteor showers of 13 NEAs were identified with the active showers produced by the δ-Cancrid meteoroid stream. The comet-like orbits of NEAs and established association with active meteor showers indicate their common cometary origin. The NEAs considered are moving within the stream and likely represent the dormant remnants of a parent comet of the δ-Cancrid asteroid-meteoroid complex.that disintegrated more than 12 thousand years ago.

关键词： asteroids comets: general meteorites meteoroids meteors minor planets δ-Cancrids

Monoclonal Antibody-Based Enzyme linked Immunosorbent Assay for the Analysis of Jasmonates in Plants

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Journal of Integrative Plant Biology 2008年第8期50卷 1046-1052页

作者： Aix.ng Deng Weiming Tan Suping He Wei liu Tiegui Nan Zhaohu li Baomin Wang Qing x. li College of Agronomy and Biotechnology China Agricultural University Beijing 100094 China Department of Molecular Biosciences and Bioengineering University of Hawaii Honolulu Hawaii 96822 USA

Methyl jasmonate （MeJA） and its free-acid form, jasmonic acid （JA） are naturally occurring plant growth regulators widely distributed in higher plants. In order to improve the sensitivity for the analysis of MeJA at low levels in small amounts of plant samples, a monoclonal antibody （MAb）（designated as MAb 3E5D7C4B6） against MeJA was derived from a JA- bovine serum albumin （BSA） conjugate as an immunogen. The antibody belongs to the IgG1 subclass with a κ type light chain and has a dissociation constant of approx.mately 6.07 ×10^-9 M. MAb3E5D7C4B6 is very specific to MeJA. It was used to develop a direct competitive enzyme-linked immunosorbent assay （dcEliSA）, conventional and simplified indirect competitive EliSAs （icEliSA）. JA was derivatized into MeJA for the EliSA analysis. The IC50 value and detection range for MeJA were, respectively, 34 and 4-257 nglmL by the conventional icEliSA, 21 and 3-226 nglmL by the simplified icEliSA and 5.0 and 0.7-97.0 nglmL by the dcEliSA. The dcEliSA was more sensitive than either the conventional or simplified icEliSA. The assays were used to measure the content of jasmonates as MeJA in tobacco leaves under drought stress or inoculated with tobacco mosaic virus and tomato leaves inoculated with tomato mosaic virus or lirioinyza sativae Blanchard as compared with the corresponding healthy leaves. The increased jasmonates content indicated its role in response to the drought stress and pathogens.

关键词： enzyme-linked immunosorbent assay immunoassay methyl jasmonate plant growth regulators

Fast　Ignition　and　Stable　Combustion　of　Coarse　Coal　Particles　in　a　Nonslagging　Cyclone　Combustor

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Journal of Thermal Science 1995年第2期4卷 136-140页

作者： Biao Zhou x. L.Wang R. x. li lix.ng Zhou(Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China) Department of Engineering Mechanics Tsinghua University Beijing China

A combustion set-up of an innovative nonslagging cyclone combustor called 'Spouting-Cyclone Combustor (SCC)' ) with two-stage combustion, organized in orthogonal vortex.flows, was established and the ex.erimental studies on the fast ignition and stable combustion of coarse coal particles in this combustor were carried out. The flame temperature versus ignition time and the practical faSt ignition procedure were obtained; The stable coal combustion can be achieved after a short period ignition, and the temperature fields in SCC were obtained. These results show that it is possible to obtain highly efficient and clean combustion of unground coal particles by using this technology.

关键词： coal combustion coal ignition cyclone combustor.

Fatigue Property of Nano-grained Delaminated Low-carbon Steel Sheet

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Journal of Materials Science & Technology 2011年第4期27卷 364-368页

作者： x. li T.F. Jing M.M. Lu R. x. B.Y. liang J.W. Zhang College of Materials Science and Engineering Yanshan University Qinhuangdao 066004 China School of Electronics and Information Engineering Liaoning Technical University Huludao 125105. China State Key Laboratory of Metastable Materials Science & Technology Yanshan University Qinhuangdao 066004 China Materials & Chemical Engineering School Zhongyuan University of Technology Zhengzhou 450007 China

Tension-tension fatigue life tests on nano-grained delaminated low-carbon steel sheet under different fatigue loads are carried out to study the fatigue properties of the steel. The three-dimensional microstructures of the steel are observed by TEM. In addition, the morphology of the fatigue fracture of the specimen under different loads is observed by SEM. The results show that micro-cracks form on the weak interface of the nano-grained steel under low-stress conditions, which hinders the propagation of the main cracks and reduces the fatigue crack propagation rate, resulting in the ex.ending fatigue life of the steel.

关键词： Nano-grained low-carbon steel Delaminated structure Tensile-tensile fatigue Weak interface

Aux.n as a Model for the Integration of Hormonal Signal Processing and Transduction

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Molecular Plant 2008年第2期1卷 229-237页

作者： W.D. Teale F.A. Ditengou A.D. Dovzhenko x. li A.M. Molendijk B. Ruperti I. Paponov K. Palme Institute of Biology Ⅱ Faculty of Biology University of Freiburg D-79104 Freiburg Germanya Dipartimento di Agronomia Ambientale e Produzioni Vegetali Agripolis University of Padova viale dell'Universita 16 35020 Legnaro Italy

The regulation of plant growth responds to many stimuli. These responses allow environmental adaptation, thereby increasing fitness. In many cases, the relay of information about a plant＇s environment is through plant hormones. These messengers integrate environmental information into developmental pathways to determine plant shape. This re- view will use, as an ex.mple, aux.n in the root ofArabidopsis thaliana to illustrate the complex.nature of hormonal signal processing and transduction. It will then make the case that the application of a systems-biology approach is necessary, if the relationship between a plant＇s environment and its growth/developmental responses is to be properly understood.

关键词： .signaling molecules Plant hormones

Crack Localization Using Transmissibility of Operational Deflection Shape and Its Application in Cantilever Beam

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Journal of Applied Mathematics and Physics 2018年第11期6卷 2352-2361页

作者： x. Z. li x. B. Yue W. Huang Institute of Mechanical Manufacturing Technology China Academy of Engineering Physics Mianyang China

Due to the nonlinearity of breathing crack, cracked structure under ex.itation of a single frequency always generates higher harmonic components. In this paper, operational deflection shape (ODS) at ex.itation frequency and its higher harmonic components are used to map the deflection pattern of cracked structure. While ODS is sensitive to local variation of structure in nature, a new concept named transmissibility of operational deflection shape (TODS) has been defined for crack localization using beam-like structure. The transmissibility indicates the energy transfer from basic frequency to higher frequency. Then, Teager energy operator (TEO) is employed as a singularity detector to reveal and characterize the features of TODS. Numerical and ex.erimental analysis in cantilever beam show that TODS has strong sensitivity to crack and can locate the crack correctly.

关键词： Crack Localization Breathing Crack Operational Deflection Shape Transmissibility

A Review on Regeneration in Cowpea （Vigna unguiculata L. Walp）

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Journal of Agricultural Science and Technology 2011年第4期5卷 525-532页

作者： x. M. li J. li M. li Y. Tang H. x. li L. Chen College of Horticulture Sichuan Agricultural University Ya ＇an 625014 Sichuan China Research Institute of Horticulture Academy of Chengdu Agriculture and Forestry Science Chengdu 61000 Sichuan China

Vigna unguiculata L. Walp is a recalcitrant plant in terms of in vitro cell, tissue and organ differentiation, which makes it difficult to apply tissue-culture dependant approaches for obtaining stable genetic transformation in cowpea. Despite this, sporadic efforts have been made to develop regeneration systems in cowpea during the past 40 years. This review presents the considerable progress on cowpea regeneration （organogenesis and embryogenesis） and especially focuses on the regeneration mode of organogenesis, including highlights of the effect of genotypes, ex.lants, medium and plant hormones used in tissue culture. The ex.sting problems and the future research directions were also discussed.

关键词： Cowpea (Vigna unguiculata L. Walp) regeneration organogenesis embryogenesis review.

Study of the Active Screen Plasma Nitriding

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材料热处理学报 2004年第5期25卷 330-333页

作者： ZhaoCheng C.x.li H.Dong T.Bell PlasmaEngineeringLaboratory QingdaoUniversityofScienceandTechnologyQingdaoChina DepartmentofMetaUurgyandMaterials UniversityofBirminghamBirminghamUK

Active screen plasma nitriding (ASPN) is a novel nitriding process, which overcomes many of the practical problems associated with the conventional DC plasma nitriding (DCPN). Ex.erimental results showed that the metallurgical characteristics and hardening effect of 722M24 steel nitrided by ASPN at both floating potential and anodic (zero) potential were similar to those nitrided by DCPN. x.D and high-resolution SEM analysis indicated that iron nitride particles with sizes in sub-micron scale were deposited on the specimen surface in AS plasma nitriding. These indicate that the neutral iron nitride particles, which are sputtered from the active screen and transferred through plasma to specimen surface, are considered to be the dominant nitrogen carrier in ASPN. The OES results show that NH could not be a critical species in plasma nitriding.

关键词：等离子渗氮 ASPN DCPN SEM

Rhamnolipids Induced by Glycerol Enhance Dibenzothiophene Biodegradation in Burkholderia sp. C3

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Engineering 2020年第5期6卷 533-540页

作者： Camila AOrtega Ramirez Abraham Kwan Qing x.li Department of Molecular Biosciences and Bioengineering University of Hawaii at ManoaHonoluluHI 96822USA

In highly urbanized areas,pollution from anthropogenic activities has compromised the integrity of the land,decreasing soil availability for agricultural ***(DBT)is a heterocyclic aromatic hydrocarbon frequently found in urbanized areas,and is often used as a model chemical to study the microbial transformation of *** potential for human ex.osure and its health risk makes DBT a chemical of concern;thus,it needs to be environmentally *** utilized glycerol to stimulate Burkholderia sp.C3 in order to degrade DBT in respect to①DBT biodegradation kinetics,②bacterial growth,③rhamnolipid(RL)biosynthesis,and④RL *** an optimum glycerol-to-DBT molar ratio,the DBT biodegradation rate constants increased up to 18-fold and enhanced DBT biodegradation by 25%–30%at day 1 relative to cultivation with DBT *** enhancement was correlated with an increase in bacterial growth and RL *** studies revealed the enzymes involved in the upper and main steps of RL *** RL congeners Rha-C10-C10,Rha-Rha-C10-C10,Rha-Rha-C10-C12,and Rha-Rha-C12-C12 were identified in the medium supplemented with glycerol and DBT,whereas only Rha-C12-C12 was identified in cultures without glycerol or with RL *** studies indicated that glycerol enhances DBT biodegradation via increased RL synthesis and bacterial *** results warrant further studies of environmental biostimulation with glycerol to advance bioremediation technologies and increase soil availability for agricultural purposes.

关键词： Biodegradation Bioremediation Biosurfactant Biotransformation Glycerol Microbial metabolism Rhamnolipid