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Electrical and optical properties of hydrogen plasma treatedβ-Ga_(2)O_(3) thin films

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Journal of Semiconductors 2022年第9期43卷 74-80页

作者： Qian Jiang junhua meng Yiming Shi Zhigang Yin Jingren Chen Jing Zhang Jinliang Wu Xingwang Zhang Key Lab of Semiconductor Materials Science Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China School of Information Science and Technology North China University of TechnologyBeijing 100144China Faculty of Science Beijing University of TechnologyBeijing 100124China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

The behavior of H inβ-Ga_(2)O_(3) is of substantial interest because it is a common residual impurity that is present inβ-Ga_(2)O_(3),regardless of the synthesis methods.Herein,we report the influences of H-plasma exposure on the electric and optical properties of the heteroepitaxialβ-Ga_(2)O_(3) thin films grown on sapphire substrates by chemical vapor deposition.The results in-dicate that the H incorporation leads to a significantly increased electrical conductivity,a greatly reduced defect-related photolu-minescence emission,and a slightly enhanced transmittance,while it has little effect on the crystalline quality of theβ-Ga_(2)O_(3) films.The significant changes in the electrical and optical properties ofβ-Ga_(2)O_(3) may originate from the formation of shallow donor states and the passivation of the defects by the incorporated H.Temperature dependent electrical properties of the H-in-corporatedβ-Ga_(2)O_(3) films are also investigated,and the dominant scattering mechanisms at various temperatures are dis-cussed.

关键词： β-Ga_(2)O_(3)film hydrogen plasma treatment electrical properties scattering mechanisms defect

基于HPLC指纹图谱与一测多评法结合的桑黄品质评价研究

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中国药学杂志 2024年第6期59卷 531-540页

作者：彭思源邓元辉丁婵孟俊华崔培梧湖南中医药大学药学院菌物药研究室长沙410208 国家中医药管理局中药药性与药效三级科研实验室长沙410208 长沙时代基因医学检验实验室长沙410000

目的基于HPLC特征图谱,建立同时测定桑黄中原儿茶酸、原儿茶醛、咖啡酸、紫萁酮和牛奶树碱5种成分含量的一测多评方法(quantitative analysis of multi-components with a single-marker,QAMS),对不同来源的桑黄药材进行品质评价研究。... 详细信息

目的基于HPLC特征图谱,建立同时测定桑黄中原儿茶酸、原儿茶醛、咖啡酸、紫萁酮和牛奶树碱5种成分含量的一测多评方法(quantitative analysis of multi-components with a single-marker,QAMS),对不同来源的桑黄药材进行品质评价研究。方法收集了3个种源地共10个批次的桑黄药材样品,采用Wondasil C_(18)Superb色谱柱(4.6 mm×250 mm,5μm),以乙腈-0.1%甲酸水溶液为流动相,梯度洗脱,体积流量1.0 mL·min^(-1),柱温25℃,进样量20μL,采用变波长程序,建立内参物原儿茶醛与原儿茶酸、咖啡酸、紫萁酮、牛奶树碱的相对校正因子并进行了相对校正因子的耐用性考察。采用外标法(external standard method,ESM)和QAMS法分别测定不同来源共10批桑黄药材中该5种成分的含量以验证QAMS法的准确性。结果采用SPSS与Origin Pro进行主成分分析、相似度分析和聚类分析。结果显示,5种成分专属性、精密度、重复性、稳定性、线性范围(r2>0.9990)均良好、平均加样回收率99.74%~102.78%,RSD 1.34%~2.92%。以原儿茶醛为内参物,原儿茶酸、咖啡酸、紫萁酮、牛奶树碱的平均相对校正因子分别为0.8519、1.4469、1.6157、0.7747;t检验结果表明,ESM法与QAMS法测定结果差异不显著。通过统计学分析实现了数据集的可视化,聚类分析发现西藏和广东产地的桑黄样品呈现一定的地域差异,但也发现了源于广东和长白山的个别桑黄样品与源于西藏的桑黄样品聚为一类的现象,意味着不能仅仅依据产地评价桑黄品质优劣,因为可能存在基源不清或品种混淆的状况。不同桑黄样品中牛奶树碱、原儿茶醛、紫萁酮的含量差异较大,且此3类成分对主成分的贡献较多,可能为桑黄的主要质量标志物。结论该研究基于HPLC指纹图谱建立的QAMS法简单、经济、实用,可以实现对桑黄中主要成分的快速、科学分析,也为其种质资源的品质评价提供了一定的科学依据。

关键词：桑黄指纹图谱一测多评法外标法相对校正因子质量评价

Direct growth of hexagonal boron nitride films on dielectric sapphire substrates by pulsed laser deposition for optoelectronic applications

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Fundamental Research 2021年第6期1卷 677-683页

作者： Gaokai Wang Jingren Chen junhua meng Zhigang Yin Ji Jiang Yan Tian Jingzhen Li Jinliang Wu Peng Jin Xingwang Zhang Key Lab of Semiconductor Materials Science Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Faculty of Science Beijing University of TechnologyBeijing 100124China

Recently,hexagonal boron nitride(h-BN),an ultra-wide bandgap semiconductor,has attracted considerable atten-tion owing to its excellent properties.In thin films grown on metal catalysts,contamination and damage induced by a transfer process cannot be avoided.Therefore,synthesizing h-BN films on non-catalytic dielectric substrates is desirable for electronic applications.In this study,we demonstrate the direct growth of high-quality h-BN films with a controllable thickness on sapphire substrates by using the pulsed laser deposition(PLD)technique.The effects of the deposition conditions and laser parameters on the growth of the h-BN films are systematically investigated by evaluating their characteristic Raman peaks.Among the various growth parameters studied,the substrate temperature has the greatest influence on the crystalline quality of the h-BN films,and the optimal pres-sure varies depending on the target-substrate distance.The h-BN film grown under optimal conditions exhibits a narrow Raman line width of∼30 cm^(−1),indicating a high crystalline quality.The photodetectors fabricated from the PLD-grown h-BN films exhibit superior deep-ultraviolet detection performance with a large on/offratio of>104,high photoresponsivity,and a sharp cut-offwavelength of 220 nm.This study presents the possibility of producing high-quality h-BN films by applying PLD on dielectric substrates for optoelectronic applications.

关键词： Hexagonal boron nitride Pulsed laser deposition Raman spectroscopy Photodetectors

大麦芽碱对B16细胞黑色素合成的影响及其机制研究

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中国医院药学杂志 2024年第5期44卷 545-549,569页

作者：吴莉靖申松夏晶王雄孟军华安靖吴金虎邹吉利陈永刚武汉市第三医院/武汉大学附属同仁医院药学部湖北武汉430065 武汉市临床检验中心湖北武汉430065 麻城市人民医院药剂科湖北麻城438300

目的:探讨大麦芽碱对B16细胞黑色素合成过程的影响及其作用机制。方法:Western blot检测大麦芽碱(50,100,200μmol·L^(-1))处理B16细胞后TYR、TRP1、TRP2的表达,判断对黑色素合成过程的影响;通过PKA激动剂处理细胞,研究大麦芽碱对B16... 详细信息

目的:探讨大麦芽碱对B16细胞黑色素合成过程的影响及其作用机制。方法:Western blot检测大麦芽碱(50,100,200μmol·L^(-1))处理B16细胞后TYR、TRP1、TRP2的表达,判断对黑色素合成过程的影响;通过PKA激动剂处理细胞,研究大麦芽碱对B16细胞黑色素合成过程的影响与cAMP/PKA/CREB/MITF信号通路的关系。结果:大麦芽碱(50,100,200μmol·L^(-1))可以抑制B16细胞黑色素组cAMP、PKA、P-CREB、MITF蛋白的表达,从而抑制黑色素合成过程中TYR、TRP1、TRP2的表达。结论:大麦芽碱可以抑制B16细胞黑色素的合成过程,其机制可能与抑制cAMP/PKA/CREB/MITF信号通路有关。

关键词：大麦芽碱黑色素 B16细胞 cAMP

Pd-Catalyzed Highly Regioselective Hydroesterification of Terminal Alkyl Olefins with Formates

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Chinese Journal of Chemistry 2024年第12期42卷 1381-1386页

作者： junhua Li Tianci Shen Yan Yang Yian Shi Jiangsu Key Laboratory of Advanced Catalytic Materials&Technology Schoolof Petrochemical EngineeringInstitute of Natural and Synthetic Organic ChemistryChangzhou UniversityChangzhouJiangsu 213164China

Comprehensive Summary A Pd-catalyzed regioselective hydroesterification of alkyl terminal olefins with aryl formates is described.A wide variety of linear carboxylic esters bearing various functional groups can be obtained in good yields with high regioselectivities under mild reaction conditions by using 1,2-DTBPMB or(p-F-Ph)3P as ligand.The reaction process is operationally simple and requires no handling of toxic CO or strong acid.The resulting aryl esters can be readily converted to other carboxylic acid derivatives.

关键词： Alkenes Regioselectivity Carbonylation Hydroesterification Formates

Trophic niche and adaptation in highland lizards:sex has greater influences than species matching

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Integrative Zoology 2024年第3期19卷 564-576页

作者： Shengnan YANG Jiapeng QU Ke TANG Xinquan ZHAO Huakun ZHOU junhua HU Chengdu Institute of Biology Chinese Academy of SciencesChengduChina Qinghai Provincial Key Laboratory of Restoration Ecology for Cold Region Northwest lnstitute of Plateau BiologyChinese Academy of SciencesXiningChina University of Chinese Academy of Sciences BeijingChina Qinghai University XiningChina

The plateau environments are typically arid,cool,and high altitude,posing formidable challenges to wildlife survival due to resource scarcity and harsh conditions.Unraveling ecological adaptability in severe conditions requires a deeper understanding of the niche characteristics of plateau species.Trophic niche,which is a comprehensive indicator describing the energy acquisition strategy of animals,remains relatively understudied in plateau species.Here,by combining stable isotopes and morphological data,we quantified the trophic niches of two allopatric lizard species(Phrynocephalus vlangalii and P.erythrurus)that live in the hinterland of the Qinghai–Tibetan Plateau,and explored how their trophic niches correlate with morphological and environmental factors.While both trophic niche and morphological traits were similar between species,noteworthy distinctions were observed between male and female Phrynocephalus lizards.The morphological traits associated with predation(i.***.limb length and head size)and reproduction(i.***.abdomen length),annual mean temperature,and sex played influential roles in shifting trophic niches.These results imply that sexual dimorphism may facilitate inter-sex divergence in resource utilization,leading to trophic niche variations in the highland lizards.Furthermore,extreme environmental stress can constrain interspecific divergence in morphological and trophic traits.Our findings illustrate the dynamic variations of trophic niches in highland lizards,contributing to a more comprehensive understanding of the adaptation strategies employed by lizard species in plateau environments.

关键词： environmental adaptation Phrynocephalus Qinghai-Tibetan Plateau sexual dimorphism stable isotope

Effective Identity Authentication Based on Multiattribute Centers for Secure Government Data Sharing

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Tsinghua Science and Technology 2024年第3期29卷 736-752页

作者： Meiquan Wang junhua Wu Tongdui Zhang Junhao Wu Guangshun Li School of Computer Science Qufu Normal UniversityRizhao 276800China Science and Technology Innovation Service Institution of Rizhao Rizhao 276800China

As one of the essential steps to secure government data sharing,Identity Authentication(IA)plays a vital role in the processing of large data.However,the centralized IA scheme based on a trusted third party presents problems of information leakage and single point of failure,and those related to key escrow.Therefore,herein,an effective IA model based on multiattribute centers is designed.First,a private key of each attribute of a data requester is generated by the attribute authorization center.After obtaining the private key of attribute,the data requester generates a personal private key.Second,a dynamic key generation algorithm is proposed,which combines blockchain and smart contracts to periodically update the key of a data requester to prevent theft by external attackers,ensure the traceability of IA,and reduce the risk of privacy leakage.Third,the combination of blockchain and interplanetary file systems is used to store attribute field information of the data requester to further reduce the cost of blockchain information storage and improve the effectiveness of information storage.Experimental results show that the proposed model ensures the privacy and security of identity information and outperforms similar authentication models in terms of computational and communication costs.

关键词： blockchain identity authentication distribution dynamic key generation

Lamellar water induced quantized interlayer spacing of nanochannels walls

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Green Energy & Environment 2024年第2期9卷 356-365页

作者： Yue Zhang Chenlu Wang Chunlei Wang Yingyan Zhang junhua Zhao Ning Wei Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment and Technology Jiangnan UniversityWuxi214122China Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas Ministry of EducationNorthwest A&F UniversityYangling712100China Zhangjiang Lab Interdisplinary Research CenterShanghai Advanced Research InstituteChinese Academy of SciencesShanghai201210China Key Laboratory of Interfacial Physics and Technology Shanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai201800China Mechanical&Automotive Engineering School of EngineeringRMIT UniversityBundooraMelbourneVICVIC 3083Australia

The nanoscale confinement is of great important for the industrial applications of molecular sieve,desalination,and also essential in bio-logical transport systems.Massive efforts have been devoted to the influence of restricted spaces on the properties of confined fluids.However,the situation of channel-wall is crucial but attracts less attention and remains unknown.To fundamentally understand the mechanism of channel-walls in nanoconfinement,we investigated the interaction between the counter-force of the liquid and interlamellar spacing of nanochannel walls by considering the effect of both spatial confinement and surface wettability.The results reveal that the nanochannel stables at only a few discrete spacing states when its confinement is within 1.4 nm.The quantized interlayer spacing is attributed to water molecules becoming laminated structures,and the stable states are corresponding to the monolayer,bilayer and trilayer water configurations,respectively.The results can potentially help to understand the characterized interlayers spacing of graphene oxide membrane in water.Our findings are hold great promise in design of ion filtration membrane and artificial water/ion channels.

关键词： Nanoconfinement Quantized spacing Lamellar water layer MD simulations Entropy force

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氧化镓薄膜外延生长及其应用研究进展

材料导报 2022年第13期36卷 13-23页

作者：蒋骞张静谢亮孟军华张兴旺北方工业大学信息学院北京100144 中国科学院半导体研究所半导体材料科学重点实验室北京100083 北京工业大学理学部北京100124 中国科学院大学材料与光电研究中心北京100049

β相氧化镓较碳化硅、氮化镓等第三代半导体材料具有更加出色的材料特性,如更宽的禁带宽度(~4.9 eV)、更高的击穿场强(~8 MV/cm)、更大的巴利加优值(3400)和更低的衬底生长成本等,在大功率电子器件和日盲探测器等方面展现出巨大的应用... 详细信息

β相氧化镓较碳化硅、氮化镓等第三代半导体材料具有更加出色的材料特性,如更宽的禁带宽度(~4.9 eV)、更高的击穿场强(~8 MV/cm)、更大的巴利加优值(3400)和更低的衬底生长成本等,在大功率电子器件和日盲探测器等方面展现出巨大的应用前景。外延生长高质量的氧化镓薄膜是制备高性能器件的前提与基础。目前,虽然在高质量氧化镓单晶生长和器件研究等方面已取得了显著进展,但是仍存在较多问题,如异质外延晶体质量的提高、p型掺杂的实现、器件性能优化等。本文总结了近年来国内外研究者在氧化镓薄膜的生长技术、同质/异质外延、半导体掺杂、电学性质、接触特性及其在功率器件和紫外光电探测器应用等方面的研究进展。

关键词：氧化镓外延缺陷掺杂