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Chinese Chemical Letters 2003年第7期14卷 697-699页

作者： Ding Qiao YANG He ping zeng Department of Chemistry South China Normal UniversityGuangzhou 510631

A new rhodium catalyzed ring opening reaction of oxabenzonorbornadienes and its derivatives was described. This reaction forms a new carbon-nitrogen bond via an intermolecular allylic displacement of the bridgehead o... 详细信息

关键词： Ring opening rhodium-catalyzed oxabenzonorbornadienes heteroatom nucleophiles.

Synthesis and Spectroscopic Study of Coumarin Derivatives

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Chemical Research in Chinese Universities 2011年第4期27卷 599-603页

作者： YAO Chun-feng zeng He-ping Institute of Functional Molecule School of Chemistry and Chemical Engineering South China University of Technology Guangzhou 510640 P. R. China Research Resources Center South China Normal University Guangzhou 510006 P. R. China

Five new coumarin amide derivatives were synthesized with coupling reagent,the structures of which were characterized by IR,1H NMR,13C NMR,MS and element *** spectral properties were studied in dichloromethane,in N,N-dimethylformamide（DMF） and in solid *** polarity has less influence on the UV-Vis maximum absorption at about 430 *** maximum emission wavelengths change from 464 nm to 474 nm in dichloromethane,from 476 nm to 482 nm in DMF and from 521 nm to 548 nm in solid state,*** fluorescence intensities of compounds 8 and 9 were extremely strong in solvents or in solid *** 8 and 9 exhibited high fluorescenct quantumn yields in solution compared to compounds 4 ＂*** fluorescence lifetimes of all the compounds in solvents were measured.

关键词： Coumarin amide derivative Fluorescence property Amide

Morphology-dependent interfacial interactions of Fe2O3 with Ag nanoparticles for determining the catalytic reduction of p-nitrophenol

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Journal of Environmental Sciences 2020年第6期32卷 1-10页

作者： Ningning Wang Shuai zeng Hong Yuan jin Huang Key Laboratory of Pesticide and Chemical Biology of Ministry of Education College of ChemistryCentral China Normal UniversityWuhan 430079China Chongqing Key Laboratory of Soft-Matter Material Chemistry and Function Manufacturing School of Chemistry and Chemical EngineeringSouthwest UniversityChongqing 400715China

In this work,we fabricated three kinds of Ag/Fe2O3 model catalysts with different morphologies to study the interfacial interactions between Ag and Fe2O3,and how they affected the catalytic activity in hydrogenation of p-nitrophenol was *** hydrothermal method was used to synthesize the metal oxide supported silver catalyst,with various morphologies including nanoplates(NPs),nanospheres(NSs),and nanocubes(NCs).The crystal structure,morphology and surface elements of the composite were investigated by various measurements,such as X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS).The catalytic activity was also evaluated by the reduction of p-nitrophenol to *** was found that the activities of the above catalysts varied with the morphology of the *** them,Ag/Fe2O3 NPs promoted the highest performance,Ag/Fe2O3 NSs were slightly inferior,and Ag/Fe2O3 NCs were the *** last,we ascribed the remarkable activity of Ag/Fe2O3 NPs to the strong metal-support interactions between Ag and Fe2O3.

关键词： Ag/Fe2O3 Interfacial interaction Catalytic activity p-Nitrophenol Morphology dependence

Characterization of Gh SERK2 and its expression associated with somatic embryogenesis and hormones level in Upland cotton

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Journal of Integrative Agriculture 2018年第3期17卷 517-529页

作者： LIU Zheng-jie ZHAO Yan-peng zeng Ling-he ZHANG Yuan WANG Yu-mei HUA jin-ping College of Agronomy and Biotechnology China Agricultural University/Key Laboratory of Crop Heterosis and Utilization Ministry of Education/Beijing Key Laboratory of Crop Genetic Improvement United States Department of Agriculture - Agricultural Research Service (USDA-ARS) Crop Genetics Research Unit Research Institute of Cash Crop Hubei Academy of Agricultural Sciences

Somatic embryogenesis （SE） is one of the most important steps during regeneration of cotton, but the molecular mechanism of SE remains unclear. SOMATIC EMBRYOGENSIS RECEPTOR KINASE （SERK） gene is known to function in SE. A homolog GhSERK2 （accession number： JF430801） was cloned from Upland cotton and characterized for its functions in SE. GhSERK2 expressed in different tissues and showed higher expression level in floral organs than vegetative ones with the highest levels in ovule and anther. GhSERK2 expressed during SE with a high level at globular embryos stage. Upon treatment with indole-3-butytic acid （IBA）, the transcription level of GhSERK2 was induced and promoted SE subsequently. A 2-day treatment of 2,4-dichlorophenoxyacetic acid （2,4-D） induced the expression of GhSERK2, but treatments of 2,4-D for longer periods sharply inhibited the GhSERK2 transcription level of embryogenic callus （EC）. The levels of hormones, including 3-indoleacetic acid （IAA）, abscisic acid （ABA）, and brassinosteroid （BR）, were increased in the initial calli induced from the over-expression of GhSERK2 cotton. Our results indicated that GhSERK2 expression was associated with induction of SE and closely related to hormone levels during tissue culture in Upland cotton, and the gene might play an important role in regeneration of cotton.

关键词： GhSERK2 somatic embryogenesis hormone level expression pattern Upland cotton (Gossypium hirsutum L.)

Preparation of calcium carbonate with microstructure and nanostructure from carbide slag for CO_(2) sequestration by using recyclable ammonium chloride

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Particuology 2024年第7期90卷 1-9页

作者： jin Yao Qiuju Chen Li zeng Wenjin Ding Key Laboratory of Ministry of Education for Solid Waste Treatment and Resource Recycle Southwest University of Science and TechnologyMianyang621010China Sichuan Engineering Lab of Non-metallic Mineral Powder Modification and High-value Utilization Mianyang621010China School of Architecture and Civil Engineering Chengdu UniversityChengdu610106China

Based on the composition characteristics of carbide slag and the application of polyvinyl chloride,a method of preparing calcium carbonate with microstructure and nanostructure by using carbide slag as a raw material and ammonium chloride as a leaching agent was *** factors for the preparation of calcium carbonate and the effects of different conditions on the crystal phase,grain size,and morphology of calcium carbonate were systematically *** results showed that the nanosized calcium carbonate was prepared at 60 mL/min,25°C,no additional ammonia,and 60 *** product of spherical vaterite was in accordance with the relevant standards for the industrial precipitation of calcium ***,the reuse of carbonation filtrate was *** crystal phase,grain size,and morphology of the carbonation product could be controlled by adjusting the reaction *** manuscript provided a new idea for resource utilization of carbide slag and preparing nanocalcium carbonate.

关键词： Carbide slag Ammonium chloride Cyclic utilization Micro and nano structure Product control

X-ray Flashes from Off-axis Nonuniform Jets

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Chinese Journal of Astronomy and Astrophysics 2004年第5期4卷 473-480页

作者： Zhi-ping jin Da-Ming Wei Purple Mountain Observatory Chinese Academy of SciencesNanjing 210008 National Astronomical Observatories Chinese Academy of SciencesBeijing 100012

It has been widely believed that the outflows in gamma-ray bursts are jetted and some jets may have structures like ∈(θ)∝θ-k. We check the possibility that X-ray flashes come from such jets. Both qualitative and quantitative analyses have shown that this model can reproduce most of the observational features of both X-ray flashes and gamma-ray bursts. Using the usual parameters of gamma-ray bursts, we have carried out numerical calculations for both uniform and nonuniform jets, of their fluxes, spectra and peak energies. It seems that nonuniform jets are more appropriate to these observational properties than uniform jets. We have also shown that in our model the observational ratio of gamma-ray bursts to X-ray flashes is about a few units.

关键词： X-rays general-gamma rays bursts-ISM jets and outflows

Experimental study of hydrogen-rich/oxygen-rich gas–gas injectors

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Chinese Journal of Aeronautics 2013年第5期26卷 1164-1172页

作者： jin ping Li Mao Cai Guobiao School of Astronautics Beihang University

Five types of coaxial injectors were investigated experimentally using hot hydrogen-rich gas and oxygen-rich gas, which were respectively provided by a GH2/GO2 hydrogen-rich perburner and a GH2/GO2 oxygen-rich preburner. The injectors were the shear coaxial injector, the oxidizer post expansion coaxial injector, the fuel impinging coaxial injector, the central body coaxial injector, and the shear tri-coaxial injector. The characteristic velocity efficiency and the combustor＇s wall temperatures were obtained for different design parameters through the experiments. It can be con- cluded that angles of the oxidizer post expansion and the fuel impinging have little influence on the combustion performance and the wall temperatures. The contact area between fuel and oxidizer and the mass flow rate have significant impacts on the combustion performance. The shear tri-coaxial injector has the best combustion performance but also the highest wall temperatures among the five types of injectors.

关键词： Combustion performance Experiment Gas-gas injector High mass flow rate Wall temperature

A survey of prototype and experiment for UAV communications

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Science China(Information Sciences) 2021年第4期64卷 5-25页

作者： Qingheng SONG Yong zeng Jie XU Shi jin College of Electrical and Information Engineeing Huaihua University Key Laboratory of Intelligent Control Technology for Wuling-Mountain Ecological Agriculture in Hunan Province National Mobile Communications Research Laboratory Southeast University Future Network of Intelligence Institute (FNii) and School of Science and Engineering The Chinese University of Hong Kong (Shenzhen)

Unmanned aerial vehicle(UAV) communications have attracted significant attention from both academia and industry. To facilitate the large-scale usage of UAVs for various applications in practice,we provide a comprehensive survey on the prototype and experiment for UAV communications. To this end, we first provide an overview on the general architecture of the prototype and experiment for UAV communications, and then present experimental verification for air-to-ground channel models and UAV energy consumption models. Next, we discuss measurement experiments on two promising paradigms of UAV communications, namely cellular-connected UAVs and UAV-enabled aerial communication platforms. For the former, we focus on the feasibility study and address the interference mitigation issue. For UAV-enabled aerial communication platforms, we present three scenarios, namely UAV-enabled aerial base stations, UAVenabled aerial relays and UAV-enabled aerial data collection/dissemination. Finally, we point out some promising future directions for prototype and experimental measurements of UAV communications.

关键词： UAV communications prototype development channel model energy efficiency UAV-enabled communications platforms cellular-connected UAVs

Joint Algorithm of Message Fragmentation and No-Wait Scheduling for Time-Sensitive Networks

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IEEE/CAA Journal of Automatica Sinica 2021年第2期8卷 478-490页

作者： Xi jin Changqing Xia Nan Guan Peng zeng Key Laboratory of Networked Control Systems Chinese Academy of SciencesShenyang 110016 Shenyang Institute of Automation Chinese Academy of SciencesShenyang 110016China Institutes for Robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang 110169China Department of Computing Hong Kong Polytechnic UniversityHong KongChina

Time-sensitive networks(TSNs)support not only traditional best-effort communications but also deterministic communications,which send each packet at a deterministic time so that the data transmissions of networked control systems can be precisely scheduled to guarantee hard real-time ***-wait scheduling is suitable for such TSNs and generates the schedules of deterministic communications with the minimal network resources so that all of the remaining resources can be used to improve the throughput of best-effort ***,due to inappropriate message fragmentation,the realtime performance of no-wait scheduling algorithms is ***,in this paper,joint algorithms of message fragmentation and no-wait scheduling are ***,a specification for the joint problem based on optimization modulo theories is proposed so that off-the-shelf solvers can be used to find optimal ***,to improve the scalability of our algorithm,the worst-case delay of messages is analyzed,and then,based on the analysis,a heuristic algorithm is proposed to construct low-delay ***,we conduct extensive test cases to evaluate our proposed *** evaluation results indicate that,compared to existing algorithms,the proposed joint algorithm improves schedulability by up to 50%.

关键词： Message fragmentation networked control system real-time scheduling time sensitive network

Robust lossless data hiding scheme

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Journal of Zhejiang University-Science C(Computers and Electronics) 2010年第2期11卷 101-110页

作者： Xian-ting zeng Xue-zeng PAN Ling-di ping Zhuo LI School of Computer Science and Technology Zhejiang University Hangzhou 310027 China College of Information Engineering China Jiliang University Hangzhou 310018 China

This paper presents a robust lossless data hiding scheme. The original cover image can be recovered without any distortion after data extraction if the stego-image remains intact, and conversely, the hidden data can still be extracted correctly if the stego-image goes through JPEG compression to some extent. A cover image is divided into a number of non-overlapping blocks, and the arithmetic difference of each block is calculated. By shifting the arithmetic difference value, we can embed bits into the blocks. The shift quantity and shifting rule are fixed for all blocks, and reversibility is achieved. Furthermore, because the bit-0- and bit-1-zones are separated and the particularity of the arithmetic differences, minor changes applied to the stego-image generated by non-malicious attacks such as JPEG compression will not cause the bit-0- and bit-l-zones to overlap, and robustness is achieved. The new embedding mechanism can enhance embedding capacity and the addition of a threshold can make the al- gorithm more robust. Experimental results showed that, compared with previous schemes, the performance of the proposed scheme is significantly improved.

关键词： Watermarking Lossless data hiding Reversible data hiding Robust lossless data hiding Semi-fragile authentication