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Investigation on the broadband electromagnetic wave absorption properties and mechanism of Co3O4- nanosheets/reduced-graphene-oxide composite

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Nano Research 2017年第3期10卷 980-990页

作者： Yi Ding Zheng Zhang Baohe Luo Qingliang Liao Shuo liu yichong liu Yue Zhang State Key Laboratory for Advanced Metals and Materials School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Beijing Municipal Key Laboratory of New Energy Materials and Technologies University of Science and Technology Beijing Beijing 100083 China

A cobaltosic-oxide-nanosheets/reduced-graphene-oxide composite （CoNSs@RGO） was successfully prepared as a light-weight broadband electromagnetic wave absorber. The effects of the sample thickness and amount of composite added to paraffin samples on the absorption properties were thoroughly investigated. Due to the nanosheet-like structure of Co3O4, the surface-to-volume ratio of the wave absorption material was very high, resulting in a large enhancement in the absorption properties. The maximum refection loss of the CoNSs@RGO composite was -45.15 dB for a thickness of 3.6 mm, and the best absorption bandwidth with a reflection loss below -10 dB was 7.14 GHz with a thickness of 2.9 mm. In addition, the peaks of microwave absorption shifted towards the low frequency region with increasing thickness of the absorbing coatings. The mechanism of electromagnetic wave absorption was attributed to impedance matching of CoNSs@RGO as well as the dielectric relaxation and polarization of RGO. Compared to previously reported absorbing materials, CoNSs@RGO showed better performance as a lightweight and highly efficient absorbing material for application in the high frequency band.

关键词： reduced graphene oxide,cobaltosic oxide nanosheets,X-ray techniques,Raman spectroscopy,dielectric loss

Influence of carrier concentration on the resistive switching characteristics of a ZnO-based memristor

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Nano Research 2016年第4期9卷 1116-1124页

作者： Yihui Sun Xiaoqin Yan Xin Zheng yichong liu Yanwei Shen Yue Zhang State Key Laboratory for Advanced Metals and Materials School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Beijing Municipal Key Laboratory of New Energy Materials and Technologies University of Science and Technology Beijing Beijing 100083 China

Sandwich-style memristor devices were synthesized by electrochemical deposition with a ZnO film serving as the active layer between Al-doped ZnO （AZO） and Au electrodes. The carrier concentration of the ZnO films is controlled by adding HNO3 during the growth process. A resulting increase in carrier concentration from 10^17 to 10^19 cm^-3 was observed, along with a corresponding drop in the on--off ratio from 6,437% to 100%. The resistive switching characteristics completely disappeared when the carrier concentration was above 1029 cm-3, making it unsuitable for a memory device. The decreasing switching ratio is attributed to a reduction in the driving force for oxygen vacancy drift. Systematic analysis of the migration of oxygen vacancies is presented, including the concentration gradient and electrical potential gradient. Such oxygen vacancy migration dynamics provide insight into the mechanisms of the oxygen vacancy drift and provide valuable information for industrial production of memristor devices.

关键词： resistive switch,carrier concentration,driving force,potential gradient,concentration gradient

The enhanced performance of piezoelectric nanogenerator via suppressing screening effect with Au particles/ZnO nanoarrays Schottky junction

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Nano Research 2016年第2期9卷 372-379页

作者： Shengnan Lu Qingliang Liao Junjie Qi Shuo liu yichong liu Qijie Liang Guangjie Zhang Yue Zhang State Key Laboratory for Advanced Metals and Materials School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Key Laboratory of New Energy Materials and Technologies University of Science and Technology Beijing Beijing 100083 China

This paper describes a novel strategy to weaken the piezopotential screening effect by forming Schottky junctions on the ZnO surface through the introduction of Au particles onto the surface. With this approach, the piezoelectric-energyconversion performance was greatly enhanced. The output voltage and current density of the Au@ZnO nanoarray-based piezoelectric nanogenerator reached 2 V and 1 μA/cm^2, respectively, 10 times higher than the output of pristine ZnO nanoarray-based piezoelectric nanogenerators. We attribute this enhancement to dramatic suppression of the screening effect due to the decreased carrier concentration, as determined by scanning Kelvin probe microscope measurements and impedance analysis. The lowered capacitance of the Au@ZnO nanoarraybased piezoelectric nanogenerator also contributes to the improved output. This work provides a novel method to enhance the performance of piezoelectric nanogenerators and possibly extends to piezotronics and piezophototronics.

关键词： screening effect,piezopotential,Schottky junction,Au@ZnO nanoarrays,piezoelectric nanogenerator

Effect of carrier screening on ZnO-based resistive switching memory devices

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Nano Research 2017年第1期10卷 77-86页

作者： Yihui Sun Xiaoqin Yan Xin Zheng Yong Li yichong liu Yanwei Shen Yi Ding Yue Zhang State Key Laboratory for Advanced Metals and Materials School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Beijing Municipal Key Laboratory of New Energy Materials and Technologies University of Science and Technology Beijing Beijing 100083 China

The carrier screening effect occurs commonly in dielectric materials. It reduces the electric potential gradient, thus negatively affecting the functionality of resistive random access memory （RRAM） devices. An Au/ZnO film/Al-doped ZnO device fabricated in this work exhibited no resistive switching （RS）, which was attributed to the carrier screening effect. Therefore, annealing was used for alleviating the screening effect, significantly enhancing the RS property. In addition, different on/off ratios were obtained for various bias values, and the screening effect was accounted for by investigating electron transport mechanisms. Furthermore, different annealing temperatures were employed to modulate the free carrier concentration in ZnO films to alleviate the screening effect. The maximal on/off ratio reached 10s at an annealing temperature of 600 ℃, yielding the lowest number of free carriers and the weakest screening effect in ZnO films. This work investigates the screening effect in RS devices. The screening effect not only modulates the characteristics of memory devices but also provides insight into the mechanism of RS in these devices.

关键词： resistive switch,carrier screening effect,carrier concentration,potential gradient,annealing

Self-powered photoelectrochemical biosensing platform based on Au NPs@ZnO nanorods array

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Nano Research 2016年第2期9卷 344-352页

作者： Zhuo Kang Xiaoqin Yan Yunfei Wang Yanguang Zhao Zhiming Bai yichong liu Kun Zhao Shiyao Cao Yue Zhang State Key Laboratory for Advanced Metals and Materials School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Key Laboratory of New Energy Materials and Technologies University of Science and Technology Beijing Beijing 100083 China

Photoanodes, which are used in photoelectrochemical （PEC） water splitting, have been shown to be applicable in the construction of a PEC biosensing platform. This was realized by replacing water oxidization with oxidation of an appropriate test molecule. Here, we have demonstrated the feasibility of adopting photoanodes consisting of zinc oxide nanorods arrays decorated with plasmonic gold nanoparticles （Au NPs@ZnO NRs） for the self-powered PEC bioanalysis of glutathione （GSH） in phosphate-buffered saline （PBS） at an applied bias potential of 0 V vs. Ag/AgCl. This heterostructure exhibited enhanced PEC properties because of the introduction of the Au/ZnO interface. Under visible light illumination, hot electrons from surface-plasmon resonance （SPR） at the Au NP surface were injected into the adjacent ZnO and subsequently driven to the photocathode. Under ultraviolet （UV） light illumination, the photogenerated electrons in ZnO tended to transfer to the fluorine-doped tin oxide due to the step-wise energy band structure and the upward energy band bending at the ZnO/ electrolyte interface. These results indicate that plasmonic metal/semiconductor heterostructure photoanodes have great potential for self-powered PEC bioanalysis applications and extended field of other photovoltaic beacons.

关键词： plasmonic gold nanoparticle,ZnO nanorod array,photoelectrochemical,biosensor,glutathione

“双循环”发展格局下中老铁路黄金通道发展对策研究

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交通与港航 2024年第2期11卷 43-49页

作者：刘译聪刘语瑶郝京京云南现代物流规划设计研究院有限公司云南省国际班列服务贸易有限公司云南省现代物流工程研究中心

通道作为现代流通体系的重要组成部分,对于畅通国内国际双循环、稳定产业链供应链、推进通道经济高质量发展具有重要作用。作为连接国内市场和南亚东南亚市场的黄金线路,中老铁路不断激发沿线活力,正成为畅通“双循环”的重要力量。基... 详细信息

通道作为现代流通体系的重要组成部分,对于畅通国内国际双循环、稳定产业链供应链、推进通道经济高质量发展具有重要作用。作为连接国内市场和南亚东南亚市场的黄金线路,中老铁路不断激发沿线活力,正成为畅通“双循环”的重要力量。基于中老铁路运营数据、沿线区域社会经济数据等,对中老铁路黄金通道的运输联系特征进行分析。结果表明:中老铁路沿线大部分站点货源处于双向不均衡状态,中老铁路货运分布呈现出向日益均衡方向演变的发展趋势,中老铁路货运空间联系呈现出以滇中城市群和环万象经济圈为主的“双中心”发展格局。在此基础上,进一步从“畅通道、织网络”“育品牌、融产业”“强合作、建生态”“优环境、提效率”四方面,提出释放中老铁路通道效能的对策建议,为“双循环”背景下国际大通道的发展路径提供参考。

关键词：双循环国际通道运输联系特征中老铁路

Design of sandwich-structured ZnO/ZnS/Au photoanode for enhanced efficiency of photoelectrochemical wate splitting

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Nano Research 2015年第9期8卷 2891-2900页

作者： yichong liu Yousong Gu Xiaoqin Yan Zhuo Kang Shengnan Lu Yihui Sun Yue Zhang State Key Laboratory for Advanced Metals and Materials School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Key Laboratory of New Energy Materials and Technologies University of Science and Technology Beijing Beijing 100083 China

We developed and demonstrated a ZnO/ZnS/Au composite photoanode with significantly enhanced photoelectrochemical water-splitting performance, con- taining a ZnS interlayer and Au nanoparticles. The solar-to-hydrogen conversion efficiency of this ZnO/ZnS/Au heterostructure reached 0.21%, 3.5 times that of pristine ZnO. The comparison of the incident photon-to-current efficiency （IPCE） and the photoresponse in the white and visible light regions further verified that the enhancement resulted from contributions of both UV and visible light. The modification of the Au NPs was shown to improve the photoelectrochemical （PEC） performance to both UV and visible light, as modification encouraged effective surface passivation and surface-plasmon- resonance effects. The ZnS interlayer favored the movement of photogenerated electrons under UV light and hot electrons under visible light, causing their injection into ZnO; this simultaneously suppressed the electron-hole recombination at the photoanode-electrolyte interface. The optimized design of the interlayer within plasmonic metal/semiconductor composite systems, as reported here, provided a facile and compatible photoelectrode configuration, enhancing the utilization efficiency of incident light for photoelectrochemical applications.

关键词： ZnO,ZnS,Au,photoanode,photoelectrochemicalwater splitting

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LEF1基因在鹅胚胎期皮肤毛囊中的表达

吉林农业大学学报 2024年第2期46卷 324-328页

作者：孙越刘静刘畅王义冲周宇轩隋玉健孙永峰吉林农业大学动物科学技术学院长春130118

为了解LEF1基因在鹅胚胎期皮肤毛囊发育过程中的作用,以胚胎期12,18,28 d的吉林白鹅和胚胎期13,18,28 d的卡洛斯鹅为试验动物。利用苏木精-伊红染色法(HE染色)对皮肤组织进行组织形态学观察,采用荧光定量PCR对LEF1基因在胚胎期鹅背部皮... 详细信息

为了解LEF1基因在鹅胚胎期皮肤毛囊发育过程中的作用,以胚胎期12,18,28 d的吉林白鹅和胚胎期13,18,28 d的卡洛斯鹅为试验动物。利用苏木精-伊红染色法(HE染色)对皮肤组织进行组织形态学观察,采用荧光定量PCR对LEF1基因在胚胎期鹅背部皮肤毛囊中的相对表达量进行检测及分析。结果表明:胚胎期为鹅初级毛囊的原始发育期,卡洛斯鹅胚胎期毛囊发育快于吉林白鹅;LEF1基因在胚胎期吉林白鹅及卡洛斯鹅的毛囊中均有表达,表达量在18 d时为高峰期。说明LEF1基因可能在胚胎期吉林白鹅及卡洛斯鹅的毛囊发育过程中发挥一定的作用。

关键词： LEF1 吉林白鹅卡洛斯鹅皮肤毛囊

儿童手掌侧瘢痕切除后采用足底全厚皮植皮的临床效果观察

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中华手外科杂志 2024年第3期40卷 215-220页

作者：周一冲林丽戴叶锋刘雨欣赵雄岳晓洁浙江大学医学院附属儿童医院烧伤整形外科、国家儿童健康与疾病临床医学研究中心杭州310052

目的观察采用足底全厚皮片移植治疗儿童手掌侧瘢痕挛缩畸形的临床效果.方法自2021年1月至2022年12月我科收治63例儿童手掌侧瘢痕挛缩畸形患儿,男34例,女29例;年龄11个月至7岁4个月,手术松解切除挛缩瘢痕组织后均采用全厚皮片移植覆盖,... 详细信息

目的观察采用足底全厚皮片移植治疗儿童手掌侧瘢痕挛缩畸形的临床效果.方法自2021年1月至2022年12月我科收治63例儿童手掌侧瘢痕挛缩畸形患儿,男34例,女29例;年龄11个月至7岁4个月,手术松解切除挛缩瘢痕组织后均采用全厚皮片移植覆盖,根据全厚皮片的供区分为足底内侧区(36例)和腹股沟区两组(27例).术后采用总主动活动度(TAM)评价两组患儿手部功能恢复情况;采用温哥华瘢痕评定量表(VSS)分别对两组患儿的植皮受区和供区的外观、色泽、血管分布及柔软度进行评价;评估手术效果的家长满意度.结果63例患儿术后随访6~18个月,TAM评价手部功能恢复情况,两组间比较差异无统计学意义(Z=0.128,P>0.05).采用VSS量表评价植皮受区和供区瘢痕,植皮受区的色泽评分,足底内侧区组低于腹股沟区组,差异有统计学意义(Z=6.589,P0.05).植皮受区手术效果的家长满意度比较,足底内侧组评价为优者的比例高于腹股沟区组,差异有统计学意义(Z=2.430,P<0.05).结论采用足底全厚皮片移植治疗儿童手掌侧瘢痕挛缩畸形,功能恢复良好,特别是对于外观的改善较为明显,临床效果确切.

关键词：儿童治疗结果手掌挛缩性瘢痕植皮全厚皮片