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direct growth of graphene on gallium nitride using C2H2 as carbon source

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Frontiers of physics 2016年第2期11卷 97-102页

作者：王兵赵云伊晓燕王国宏刘志强段瑞飞黄鹏王军喜李晋闽 Semiconductor Lighting Technology r&d center Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China

Growing graphene on gallium nitride （GaN） at temperatures greater than 900℃ is a challenge that must be overcome to obtain high quality of GaN epi-layers. We successfully met this challenge using C2H2 as the carbon source. We demonstrated that graphene can be grown both on copper and directly on GaN epi-layers. The raman spectra indicated that the graphene films were about 4-5 layers thick. Meanwhile, the effects of the growth temperature on the growth of the graphene films were systematically studied, and 830℃ was found to be the optimum growth temperature. We successfully grew high-quality graphene films directly on gallium nitride.

关键词： graphene C2H2 gallium nitride chemical vapor deposition raman spectroscopy

Ontogeny of the immune system in rock bream Oplegnathus fasciatus

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Chinese Journal of Oceanology and Limnology 2013年第5期31卷 1028-1035页

作者：肖志忠何滔李军高天翔 Ocean University of China center of Biotechnology r&d Institute of Oceanology Chinese Academy of Sciences Southwest University

Histogenesis of the immune system and specific activity of superoxide dismutase(SOd) were studied in rock bream Oplegnathus fasciatus from fertilization to 50 days after hatching(dAH).The pronephric tubule primordium developed in the embryo,14 h 30 min post *** spleen anlage was observed between the swim bladder and the intestine at 5 dAH,and the thymus was formed as a paired structure under the pharyngeal epithelium above the gill arch at 10 *** order of the immune organs becoming lymphoid was the pronephric kidney(10 dAH),thymus(15 dAH) and spleen(21 dAH).As the embryo developed,the specific activity of SOd gradually increased until hatching,but subsequently SOd activity continuously decreased to a minimum at 14 *** the spleen became lymphoid,the specific activity of SOd was relatively *** is suggested that the immaturity of the lymphoid organs and low specific activity of SOd was the cause of the high mortality of fingerlings 12 to 16 dAH.

关键词： rock bream ontogeny immune system superoxide dismutase (SOd)

Secret key generation based on private pilot under man-in-the-middle attack

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Science China(Information Sciences) 2017年第10期60卷 93-106页

作者： Yu HUANG Liang JIN Na LI Zhou ZHONG Xiaoming XU National digital Switching System Engineering and Technological r&d center National Engineering Laboratory for Mobile Network Technologies Beijing University of Posts and Telecommunications

Given the openness and invariance of public pilot, secret key generation(SKG) based on wireless channels is vulnerable to active attacks. In this paper, we explore man-in-the-middle(MITM) attacks, where the attacker acts as a transparent relay to intercept channel state information and deduce the generated *** prevent this type of attacks, a dynamic private pilot is generated, where legitimate nodes first consider the information authenticated between them as seed information for the private pilot, and then generate the private pilot based on this seed information according to the pilot requirements. Then, both the new seed information and secret keys are dynamicaally derived from wireless channels that are estimated with the private pilot instead of a public pilot. The proposed private pilot encrypts and authenticates wireless channels, allowing an SKG rate close to that without attackers. Analysis and simulation results show that the proposed SKG approach can effectively withstand an MITM attack.

关键词： private pilot man-in-the-middle attack secret key generation physical layer security

A novel differentiated services supporting scheme for optical burst switched networks

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Chinese Optics Letters 2003年第7期1卷 392-394页

作者：王建新曾庆济张治中池灏 r&d center for Broadband Optical Networking Technology (CBONT) Shanghai Jiaotong University Shanghai 200030

In this letter, we analyze the drawback of tail-dropping contention resolution in optical burst switched networks. Once contention occurs, we adopt modified head-dropping policy to resolve contention. This policy drops the head of the contending burst only if the overlapping region of the two bursts is less than the whole contending burst size, otherwise drops the whole contending burst. In order to have a better support of differentiated service, a new burst assembly policy, namely, Priority-based proportional mixed burst assembly, is proposed. Simulation results show that the proposed scheme performs very well in terms of performance metrics such as the times of contention and packet loss probability.

关键词： node it for A novel differentiated services supporting scheme for optical burst switched networks been than OBS of that in

Preparation and characterization of Li_(4)Ti_(5)O_(12) synthesized using hydrogen titanate nanowire for hybrid super capacitor

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Journal of Advanced Ceramics 2013年第3期2卷 285-290页

作者： Jong Hyun KIM Jung rag YOON r&d center Samwha Capacitor Co.Ltd.YonginGyeonggi 449-884R.O.Korea

The electrical characteristics of hybrid super capacitor were evaluated by synthesizing LTO(Li_(4)Ti_(5)O_(12))using TiO_(2) having a hydrogen titanate nanowire *** of the hydrogen titanate nanowire was implemented by using TiO_(2) having size of 60 nm and NaOH,and performing synthesis at 70℃for 6 h with a sonochemical *** compound was synthesized at 150℃for 36 h and at 180℃for 36 h respectively by using the hydrogen titanate nanowire and LiOH·H2O as starting materials with a hydrothermal *** final LTO compound was synthesized at 700℃for 6 h using a solid-state *** a result of manufacturing the hybrid super capacitor using LTO synthesized at 180℃for 36 h with the hydrothermal method,a capacity of 198 mA·h/g has been achieved compared to a theoretical capacity of 172 mA·h/g of existing LTO,and thus,the capacity has been increased by about 13%.Further,such excellent cycle performance has ensured its possibility as a high-capacity capacitor.

关键词： LTO(Li4Ti5O12) lithium titanate oxide hydrogen titanate nanowire hybrid super capacitor

Synthesis ofα-Li FeO_(2)/Graphene nanocomposite via layer by layer self-assembly strategy for lithium-ion batteries with excellent electrochemical performance

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Journal of Materials Science & Technology 2020年第20期52卷 173-181页

作者： Youzuo Hu Hongyuan Zhao Ming Tan Jintao Liu Xiaohui Shu Meiling Zhang Shanshan Liu Qiwen ran Hao Li Xingquan Liu r&d center for New Energy Materials and Integrated Energy devices University of Electronic Science and Technology of ChinaChengdu 610054China

As a potential alternative cathode material,α-LiFeO2 suffers a realization handicap,mainly due to its poor electrical conductivity and low lithium ion diffusion *** this work,we have successfully synthesized α-LiFeO2/rGO nanocomposite through a layer by layer self-assembly modification process and annealing *** to the strong electrostatic attraction between opposite cha rged spices,α-LiFeO2 nanoparticles were homogeneously dispersed on the graphene sheet to form a typical interconnected conducting network which was bene ficial for electronic conductivity and ionic diffu *** comparison to pristine α-LiFeO2,the α-LiFeO2/rGO displayed an excellent electrochemical perfo rmance with average discharge capacities of 238.9,187.2,178.4,121.8 and 99.5 mA hg^-1 at 0.1,0.2,0.5,1 and 2 C,***,the specific capacity retained 164.9 mA h g^-1 and 107.98 mA h g^-1 after 50 cycles at 0.5 C and 1 C,*** remarkable progress in rate capability and cycling ability of this new nanocomposite developed a new approach to improve the electrochemical performance of α-LiFeO2.

关键词： α-LiFeO_(2) Lithium ion battery Graphene Layer by layer self-assembly

Acute and chronic excitotoxicity in ischemic stroke and late-onset Alzheimer's disease

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Neural regeneration research 2025年第7期20卷 1981-1988页

作者： Shan Ping Yu Emily Choi Michael QJiang Ling Wei department of Anesthesiology Emory University School of MedicineAtlantaGAUSA center for Visual and Neurocognitive rehabilitation Atlanta Veterans Affairs Medical CenterDecaturGAUSA

Stroke and Alzheimer's disease are common neurological disorders and often occur in the same *** comorbidity of the two neurological disorders represents a grave health threat to older *** review presents a brief background of the development of novel concepts and their clinical *** activity of glutamatergic N-methyl-d-aspartate receptors and N-methyl-d-aspartate receptor-mediated Ca^(2+)influx is critical for neuronal *** ischemic insult induces prompt and excessive glutamate release and drastic increases of intracellular Ca^(2+)mainly via N-methyl-d-aspartate receptors,particularly of those at the extrasynaptic *** Ca^(2+)-evoked neuronal cell death in the ischemic core is dominated by necrosis within a few hours and days known as acute ***,mild but sustained Ca^(2+)increases under neurodegenerative conditions such as in the distant penumbra of the ischemic brain and early stages of Alzheimer's disease are not immediately toxic,but gradually set off deteriorating Ca^(2+)-dependent signals and neuronal cell loss mostly because of activation of programmed cell death *** on the Ca^(2+)hypothesis of Alzheimer's disease and recent advances,this Ca^(2+)-activated“silent”degenerative excitotoxicity evolves from years to decades and is recognized as a unique slow and chronic *** N-methyl-d-aspartate receptor subunit GluN3A,primarily at the extrasynaptic site,serves as a gatekeeper for the N-methyl-d-aspartate receptor activity and is neuroprotective against both acute and chronic *** stroke and Alzheimer's disease,therefore,share an N-methyl-d-aspartate receptor-and Ca^(2+)-mediated mechanism,although with much different time *** is thus proposed that early interventions to control Ca^(2+)homeostasis at the preclinical stage are pivotal for individuals who are susceptible to sporadic late-onset Alzheimer's disease and Alzheimer's disease-related

关键词： Ca^(2+)hypothesis cognitive deficits hyperactivity late-onset Alzheimer's disease neurodegeneration N-methyl-d-aspartate receptors N-methyl-d-aspartate receptor subunits pathogenesis preventive treatment

N-doped NaTaO3 synthesized from a hydrothermal method for photocatalytic water splitting under visible light irradiation

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Journal of Energy Chemistry 2017年第3期26卷 515-521页

作者： Che-Chia Hu Hui-Hsin Huang Yu-Chi Huang department of Chemical Engineering and r&d center for Membrane Technology Chung Yuan Christian UniversityTaoyuan City 32023TaiwanChina

NaTaONcatalysts were synthesized by a hydrothermal（H） and a solid-state（S） methods in this *** H-and S-NaTaONsamples were characterized by X-ray diffraction（Xrd）, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, UV–visible（UV–vis） diffuse reflectance spectroscopy, and photoluminescence（PL） spectroscopy. The Xrd patterns of the H-and S-samples showed peaks indexed to the pure phase of perovskite NaTaOand minor peaks assignable to TaNat various synthesis temperatures. Substitution of oxygen by nitrogen ions causes the light absorption of the H-and S-NaTaONsamples to be extended to the 600–650 nm region, thus making the samples visible-light active. The NaTaONsamples exhibited photocatalytic activity for Hand Oevolution from aqueous methanol and silver nitrate solutions under visible-light irradiation. The UV–vis and PL spectra of the Hand S-catalysts revealed the presence of cationic vacancies and reduced metallic species, which acted as recombination centers. These results demonstrated that the preparation method plays a critical role in the formation of defect states, thereby governing the photocatalytic activity of the NaTaONcatalysts.

关键词： Photocatalysis H2 production N-doped NaTaO3 Hydrothermal method Visible light

Effect of Solute Contents of Al-Ni-Sr Alloy on Glass Forming Ability and Thermal Stability

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Journal of rare Earths 2004年第Z2期22卷 73-77页

作者： Taek Soo Kim J K Lee H J Kim J C Bae Advanced Materials r&d center Korea Institute of Industrial Technology994-32 Dongchun-dongYeonsu-kuIncheon 406-130Korea Advanced Materials R&D CenterKorea Institute of Industrial Technology994-32 Dongchun-dongYeonsu-kuIncheon 406-130Korea Advanced Materials R&D CenterKorea Institute of Industrial Technology994-32 Dongchun-dongYeonsu-kuIncheon 406-130Korea Advanced Materials R&D CenterKorea Institute of Industrial Technology994-32 Dongchun-dongYeonsu-kuIncheon 406-130Korea

Glass forming ability (GFA) and structural characterization of a new amorphous Al-Ni-Sr alloy melt spun were investigated on the theory of the factors for the glass formation. The GFA was varied with the ratio of Ni to Sr in detail and successful amorphous phase dispersed with 2 ～ 5 nm precipitates was prepared from Al-Ni5-Sr3. Thermal stability and crystallization behavior of the amorphous phase were determined by continuous and isothermal heating technique on dCS, resulting that the crystallization occurs by the growth of fcc Al nanocrystals on the preexistent nuclei.

关键词： glass formation crystallization Al base amorphous alloys rapid solidification