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Numerical simulation of gap effect in supersonic flows 被引量:1
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作者 Song Mo Haiming Huang +2 位作者 Guo Huang Xiaoliang Xu Zimao Zhang 《Theoretical & Applied Mechanics Letters》 CAS 2014年第4期65-69,共5页
The gap effect is a key factor in the design of the heat sealing in super- sonic vehicles subjected to an aerodynamic heat load. Built on S-A turbulence model and Roe discrete format, the aerodynamic environment aroun... The gap effect is a key factor in the design of the heat sealing in super- sonic vehicles subjected to an aerodynamic heat load. Built on S-A turbulence model and Roe discrete format, the aerodynamic environment around a gap on the surface of a supersonic aircraft was simulated by the finite volume method. As the presented results indicate, the gap effect depends not only on the attack angle, but also on the Mach number. 展开更多
关键词 gap effect supersonic flow numerical simulation thermal protection
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Influence of social capital on farmer household income gap:total effect and structural effect 被引量:1
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作者 Geling Wang Qian Lu 《Chinese Journal of Population,Resources and Environment》 2016年第1期30-37,共8页
Based on the survey data of typical villages in Shaanxi Province,China,the effect of social capital on the income gap of farmers' households was analyzed using the Shapley value of the total amount of social capit... Based on the survey data of typical villages in Shaanxi Province,China,the effect of social capital on the income gap of farmers' households was analyzed using the Shapley value of the total amount of social capital and the social capital structure.The results show the following:first,social capital can expand the household income gap,and the effect of this index on the household income gap is 7.54%.Second,the indexes of the social capital dimension can expand the household income gap,and the structural effects of the household income gap on social networks,social trust,and social participation are 3.17%,3.64%,and 0.65%,respectively.Third,no dimension of the path is the same as the effect on the household income gap. 展开更多
关键词 Income gap social capital structural effect total effect
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Pharmacological Effects of Statins Related to Gap Junction Modulation 被引量:1
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作者 Lili Qu Jiandong Jiang Weijia Kong 《Pharmacology & Pharmacy》 2014年第4期319-331,共13页
3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, or “statins”, are widely using cholesterol-lowering drugs with pleiotropic pharmacological effects. In this review, we summarized the pharmacolog... 3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, or “statins”, are widely using cholesterol-lowering drugs with pleiotropic pharmacological effects. In this review, we summarized the pharmacological effects of statins related to gap junction modulation. The main function of cellular gap junctions, which are composed of trans-membrane proteins named connexins (Cxs), is to mediate direct cell-to-cell communication through material exchange. Statins could rectify the disturbed expression, distribution, or phosphorylation of Cxs and thus modify the functions of gap junctions in a variety of tissues like the aorta, cardiomyocytes, or tumors. The effects of statins on Cxs and gap junctions were associated with their pharmacological activities against atherosclerosis, arrhythmias, and tumors. Despite some evidences suggested that the anti-inflammatory or HMG-CoA reductase inhibiting effects of statins may contribute in part to the modulation of Cxs and gap junctions, the detailed underlying mechanisms are largely unrevealed and merit further investigation. In addition, it is likely that the modulating effects of statins on gap junctions may also contribute to their pharmacological activities against some diabetic complications. Future studies of these issues will help to provide scientific evidences for the appropriate clinical application of statins. 展开更多
关键词 STATIN CONNEXIN gap JUNCTION ATHEROSCLEROSIS ARRHYTHMIA BYSTANDER effect
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LiF/GAP协同作用改善硼粉的燃烧性能
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作者 伍双艳 王吉权 +4 位作者 邵建 刘俊 陈九玉 朱宝忠 孙运兰 《火炸药学报》 EI CAS CSCD 北大核心 2024年第3期279-286,I0006,共9页
以氟化锂/缩水甘油叠氮化物聚合物(LiF/GAP)为界面层对微米硼进行改性,研究LiF/GAP协同作用对硼粉热行为、燃烧性能和凝聚相燃烧产物的影响。结果表明,通过硅烷偶联剂处理后,硼粉表面黏结性得以提高,LiF能够较好地包覆在硼粉表面;GAP在... 以氟化锂/缩水甘油叠氮化物聚合物(LiF/GAP)为界面层对微米硼进行改性,研究LiF/GAP协同作用对硼粉热行为、燃烧性能和凝聚相燃烧产物的影响。结果表明,通过硅烷偶联剂处理后,硼粉表面黏结性得以提高,LiF能够较好地包覆在硼粉表面;GAP在400℃之前抑制了LiF与硼表面氧化膜的反应,使LiF的除膜效应延后至硼粉氧化增重阶段,从而将更多的活性硼暴露在空气中发生氧化,促进了硼粉的燃烧;LiF和GAP协同作用显著改善了硼粉的燃烧性能,尤其当LiF和GAP质量分数均为10%时,作用效果最为明显。此外,LiF和GAP协同作用有效抑制了燃烧过程中硼粉团聚,使其凝聚相燃烧产物粒径降低。 展开更多
关键词 物理化学 硼颗粒 LiF/gap协同作用 燃烧特性 团聚抑制 燃烧机理
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Tunable Band Gap in Piezoelectric Composite Rod Based on the Inter-Coupling Effect
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作者 Ze-Qun Fang Zhi-Lin Hou 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第5期60-64,共5页
The longitudinal wave propagating in one-dimensional periodic piezoelectric composite rod with inter-coupling between different piezoelectric segments is investigated. The analytical formulae for such a structure are ... The longitudinal wave propagating in one-dimensional periodic piezoelectric composite rod with inter-coupling between different piezoelectric segments is investigated. The analytical formulae for such a structure are shown and the dispersion relation is calculated. The results show that, by introducing the inter-coupling between the different piezoelectric segments, which is accomplished by serially connecting every n piezoelectric segment into supercells, some tunable Bragg band gaps can accordingly be opened in the low frequency region. The investigation could provide a new guideline for the tunable phononic crystal under passive control. 展开更多
关键词 UUT Tunable Band gap in Piezoelectric Composite Rod Based on the Inter-Coupling effect TP BG TN
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Improved photovoltaic effects in Mn-doped BiFeO3 ferroelectric thin films through band gap engineering
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作者 阎堂柳 陈斌 +7 位作者 刘钢 牛瑞鹏 尚杰 高双 薛武红 金晶 杨九如 李润伟 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第6期401-405,共5页
As a low-bandgap ferroelectric material, BiFeO3 has gained wide attention for the potential photovoltaic applications,since its photovoltaic effect in visible light range was reported in 2009. In the present work, Bi... As a low-bandgap ferroelectric material, BiFeO3 has gained wide attention for the potential photovoltaic applications,since its photovoltaic effect in visible light range was reported in 2009. In the present work, Bi(Fe, Mn)O3thin films are fabricated by pulsed laser deposition method, and the effects of Mn doping on the microstructure, optical, leakage,ferroelectric and photovoltaic characteristics of Bi(Fe, Mn)O3 thin films are systematically investigated. The x-ray diffraction data indicate that Bi(Fe, Mn)O3 thin films each have a rhombohedrally distorted perovskite structure. From the light absorption results, it follows that the band gap of Bi(Fe, Mn)O3 thin films can be tuned by doping different amounts of Mn content. More importantly, photovoltaic measurement demonstrates that the short-circuit photocurrent density and the open-circuit voltage can both be remarkably improved through doping an appropriate amount of Mn content, leading to the fascinating fact that the maximum power output of ITO/BiFe(0.7)Mn(0.3)O3/Nb-STO capacitor is about 175 times higher than that of ITO/BiFeO3/Nb-STO capacitor. The improvement of photovoltaic response in Bi(Fe, Mn)O3 thin film can be reasonably explained as being due to absorbing more visible light through bandgap engineering and maintaining the ferroelectric property at the same time. 展开更多
关键词 band gap engineering BIFEO3 Mn doping FERROELECTRIC photovoltaic effect
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Study on Stack Effect of Stairwell by Numerical Model of Leakage Flow through Gap of Door
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作者 Jung-Yup Kim Ji-Seok Kim 《Open Journal of Fluid Dynamics》 2013年第4期241-247,共7页
Since stack effect that occurs in high-rise buildings has an effect on the indoor environment of the buildings, energy loss and smoke control in case of a fire, there is a need to conduct research on this. For an anal... Since stack effect that occurs in high-rise buildings has an effect on the indoor environment of the buildings, energy loss and smoke control in case of a fire, there is a need to conduct research on this. For an analysis of the stack effect, analysis methods on the leakage flow through gap of interior door shall be formulated. Until now, studies related to the gap leakage flow in buildings have mainly analyzed flow field and pressure in the buildings one-dimensionally using pressure difference-leakage flowrate relations of Orifice Equation and a network numerical analysis algorithm that as- sumes each compartment in the buildings as a single point. In this study, the Momentum Loss Model which enables pressure drop to be proportional to the flow velocity through the gap of door in computational domain of 3-dimensional numerical analysis was proposed to reflect the gap flow phenomenon effectively in 3-dimensional numerical analysis. Using the proposed model, 3-dimensional numerical analysis of the stack effect on the stairs in buildings was performed, and the effects of separation door and lobby between stair and accommodation on the stack effect were investigated. 展开更多
关键词 STACK effect LEAKAGE Flow gap of DOOR MOMENTUM Loss Model Separation DOOR NUMERICAL Analysis
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Effects of Hydroxyl Radicals on Introduced Organisms of Ship's Ballast Water Based Micro-Gap Discharge 被引量:2
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作者 白敏冬 张芝涛 +2 位作者 白敏菂 杨波 白希尧 《Plasma Science and Technology》 SCIE EI CAS CSCD 2007年第2期206-210,共5页
With the physical method of micro-gap gas discharge, OH. radicals were produced by the ionization of O2 in air and H2O in the gaseous state, in order to explore more effective method totreat the ship's ballast water.... With the physical method of micro-gap gas discharge, OH. radicals were produced by the ionization of O2 in air and H2O in the gaseous state, in order to explore more effective method totreat the ship's ballast water. The surface morphology of Al2O3 dielectric layer was analysed using Atomic Force Microscopy (AFM), where the size of Al2O3 particles was in the range of 2 μm to 5 μm. At the same time, the biochemical effect of hydroxyl radicals on the introduced organisms and the quality of ship's ballast water were studied. The results indicate that the main reasons of cell death are lipid peroxide and damage of the antioxidant enzyme system in Catalase (CAT), Peroxidase (POD) and Superoxide dismutase (SOD). In addition, the quality of the ballast water was greatly improved. 展开更多
关键词 micro-gap discharge α-Al2O3 dielectric layers introduced organisms hydroxyl radical biochemistry effect
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益气活血中药对脑出血大鼠GAP-43和Arc的影响 被引量:2
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作者 李艳青 谢荃 《中医临床研究》 2016年第30期77-78,共2页
目的:观察益气活血中药制剂对脑出血大鼠脑组织GAP-43和Arc的影响。方法:用自体血注入法建立大鼠脑出血模型,分空白组、阳性组和实验组。阳性组造模1 d后开始腹腔注射神经节苷脂;实验组造模1 d后用益气活血中药制剂灌胃。分别于干预后1 ... 目的:观察益气活血中药制剂对脑出血大鼠脑组织GAP-43和Arc的影响。方法:用自体血注入法建立大鼠脑出血模型,分空白组、阳性组和实验组。阳性组造模1 d后开始腹腔注射神经节苷脂;实验组造模1 d后用益气活血中药制剂灌胃。分别于干预后1 d、3 d、7 d处死大鼠,用定量PCR法检测各组大鼠脑组织GAP-43和Arc的水平。结果:干预后第7天阳性组与实验组大鼠脑组织GAP-43和Arc含量均高于空白组,差异有统计学意义;第3天实验组GAP-43含量高于阳性组,与阳性组比较差异有统计学意义。结论:益气活血中药制剂对大鼠脑出血损伤后神经结构重建有促进作用,但具体作用机制尚需进一步研究。 展开更多
关键词 中医内科学 益气活血 gap-43 ARC 影响
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85MeV^(19)F离子辐照GaP的正电子湮没研究
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作者 王荣 徐勇军 +1 位作者 黄龙 朱升云 《核技术》 CAS CSCD 北大核心 2001年第4期274-276,共3页
用正电子湮没寿命技术研究了 2 .4× 10 15 cm2 和 2 .2× 10 16 cm2 85MeV19F离子辐照GaP的辐照效应。结果表明 ,辐照在GaP中产生浓度较高的单空位 。
关键词 辐照效应 正电子湮没 抗辐射性能 磷化镓半导体 氟19离子辐照
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温度和拉伸速率对硝酸酯增塑的GAP/CL–20固体推进剂拉伸力学行为的影响 被引量:1
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作者 周水平 吴芳 +1 位作者 唐根 庞爱民 《化学推进剂与高分子材料》 CAS 2016年第5期48-52,共5页
通过单轴拉伸实验获得了聚叠氮缩水甘油醚(GAP)/六硝基六氮杂异伍兹烷(CL–20)推进剂在–40-70℃和0.5-5 000 mm/min的拉伸速率(ν)下的应力–应变曲线。GAP/CL–20推进剂的力学性能呈现明显的温度(t)和拉伸效应,温度和拉伸的... 通过单轴拉伸实验获得了聚叠氮缩水甘油醚(GAP)/六硝基六氮杂异伍兹烷(CL–20)推进剂在–40-70℃和0.5-5 000 mm/min的拉伸速率(ν)下的应力–应变曲线。GAP/CL–20推进剂的力学性能呈现明显的温度(t)和拉伸效应,温度和拉伸的“耦合”作用,使推进剂的力学性能发生显著的变化。初始弹性模量和最大拉伸强度σm随t的降低与ν的升高逐渐增加,σm与lnν呈线性关系。与模量和强度相比,最大伸长率εm和断裂伸长率εb的变化规律较为复杂:低温时,推进剂的εm和εb与lnν呈二次方关系,并随t的上升,先上升后下降;高温时,推进剂的εm和εb与lnν呈线性关系,随t的上升显著下降。 展开更多
关键词 gap/CL-20推进剂 力学性能 耦合效应 拉伸速率 温度
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Gap效应对搜索目标显著性和绩效的影响 被引量:2
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作者 徐新然 郭肖亚 于瑞峰 《工业工程》 北大核心 2021年第1期117-122,共6页
探究了gap效应对视觉搜索任务中搜索目标的显著性和搜索绩效的影响。采用gap值(11种时间值)×极性(正极性和负极性)×角度(30°/60°,20°/70°)3因子组内设计实验,18名被试在不同gap值、极性和角度组合条件下... 探究了gap效应对视觉搜索任务中搜索目标的显著性和搜索绩效的影响。采用gap值(11种时间值)×极性(正极性和负极性)×角度(30°/60°,20°/70°)3因子组内设计实验,18名被试在不同gap值、极性和角度组合条件下完成一系列视觉搜索任务,测量指标为发现目标物的概率和反应时间。结果表明,gap值、角度及二者的交互作用对搜索目标的显著性有显著影响,gap值和极性对反应时间有显著影响,即gap效应对视觉搜索任务中搜索目标的显著性和搜索绩效均有显著影响。 展开更多
关键词 视觉搜索 显著性 gap效应 显示极性 人因工程
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Study on Axial Flux Hysteresis Motors Considering Airgap Variation 被引量:1
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作者 Mohammad Modarres Abolfazl Vahedi Mohammadreza Ghazanchaei 《Journal of Electromagnetic Analysis and Applications》 2010年第4期252-257,共6页
Axial flux hysteresis motor (AFHM) is self-starting synchronous motor that uses the hysteresis characteristics of magnetic materials. It is known that the magnetic characteristics of hysteresis motor could be easily a... Axial flux hysteresis motor (AFHM) is self-starting synchronous motor that uses the hysteresis characteristics of magnetic materials. It is known that the magnetic characteristics of hysteresis motor could be easily affected by air gap and structure dimensions variation. Air gap length plays an important role in flux distribution in hysteresis ring and influences the output torque, terminal current, efficiency and even optimal value of other structural parameters of AFHM. Regarding this issue, in this study effect of air gap variation on performance characteristics of an axial flux hysteresis motor and effect of air gap length on hysteresis ring thickness and stator winding turns is investigated. Effect of air gap length on electrical circuit model is perused. Finally, simulation of AFHM in order to extract the output values of motor and sensitivity analysis on air gap variation is done using 3D-Finite Element Model. Hysteresis loop in the shape of an inclined ellipse is adopted. This study can help designers in design approach of such motors. 展开更多
关键词 HYSTERESIS LOOP AXIAL FLUX HYSTERESIS MOTOR 3D-FEM Model Complex PERMEABILITY Air gap effect
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GaP高能重离子辐照损伤及退火的正电子湮没研究
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作者 黄龙 王荣 +1 位作者 徐勇军 朱升云 《核技术》 EI CAS CSCD 北大核心 2000年第6期359-362,共4页
用正电子湮没寿命技术研究了2.4×1015/cm2和2.2×1016/cm285MeV19F离子辐照GaP的辐照损伤及其退火效应。结果表明,高低两种注量辐照在GaP中产生浓度较高的单空位。在300—1023K温度范围内测量了正电子湮没寿命随退火温度... 用正电子湮没寿命技术研究了2.4×1015/cm2和2.2×1016/cm285MeV19F离子辐照GaP的辐照损伤及其退火效应。结果表明,高低两种注量辐照在GaP中产生浓度较高的单空位。在300—1023K温度范围内测量了正电子湮没寿命随退火温度的变化。低注量辐照样品在退火过程中有双空位的形成;而高住量辐照样品中观察到比双空位更复杂的缺陷形式,其完全被退火的温度比低剂量辐照的高250K。 展开更多
关键词 ^19F离子 辐照损伤 退火效应 正电子湮没 磷化镓
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A Methodology of Metamaterial Effective Permittivity and Permeability Value Measurement
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作者 A. S. Kukharenko R. V. Shaymardanov A. A. Yelizarov 《材料科学与工程(中英文A版)》 2017年第4期206-215,共10页
关键词 等效介电常数 测量方法 磁导率 材料 电介质结构 有效介电常数 矢量网络分析仪 测量工具
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Study on the Forbidden Gap Width of Strained Epitaxial Lead Selenide Layers by Optical Transmission
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《材料科学与工程(中英文B版)》 2012年第2期142-150,共9页
关键词 禁带宽度 硒化铅 应变层 光传输 吸收系数 光纤传输 光子能量 双向拉伸
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我国教育投入产出对收入差距影响的实证研究 被引量:2
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作者 张茂聪 薛翔宇 +1 位作者 范晓婷 陈倩 《经济与管理评论》 CSSCI 北大核心 2024年第2期136-149,共14页
我国迅速发展的教育事业为经济社会发展做出了巨大贡献,为探究我国教育事业发展对收入差距产生的影响,选取1999-2020年我国31个省份相关数据,通过双固定效应模型、空间计量模型等方法展开实证分析。研究发现,教育投入会显著缩小本地区... 我国迅速发展的教育事业为经济社会发展做出了巨大贡献,为探究我国教育事业发展对收入差距产生的影响,选取1999-2020年我国31个省份相关数据,通过双固定效应模型、空间计量模型等方法展开实证分析。研究发现,教育投入会显著缩小本地区收入差距,教育产出显著地扩大了本地区的收入差距;机制分析结果表明,教育投入具有公平效应,且该过程会受到经济发展水平及政府其他资源配置能力的影响,教育产出更具马太效应,且该作用通过影响科技创新水平表现出来并受到劳动力市场情况的影响;空间计量结果表明,教育投入会缩小相邻地区收入差距,教育产出未对相邻地区收入差距产生作用。据此提出持续加大教育投入、继续发挥多次分配作用、政府政策发挥导向作用、完善其他配套政策等建议。 展开更多
关键词 教育投入与产出 收入差距 公平效应 马太效应 空间效应
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Reflections on Grammar and Effective Communication
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作者 Shan Yan 《学术界》 CSSCI 北大核心 2015年第8期308-311,共4页
Grammar constitutes the frame of a language,which a person communicating in that language no doubt needs to know about. Both grammar and communication are inseparable. Without internalized knowledge of grammar,the eff... Grammar constitutes the frame of a language,which a person communicating in that language no doubt needs to know about. Both grammar and communication are inseparable. Without internalized knowledge of grammar,the effectiveness to learn and to communicate in the target language may be handicapped. This paper focuses on grammar and effective communication and expounds the communicative properties of grammar from functional view. 展开更多
关键词 语法知识 目标语言 残疾人 分割 学习
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Effect of annealing treatment on optical and electrical properties of ZnO films
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作者 王万录 廖克俊 +3 位作者 李丽 吴子华 王永田 张津 《中国有色金属学会会刊:英文版》 CSCD 2005年第2期410-413,共4页
The ZnO-Al films were prepared by R.F. magnetron sputtering system using a Zn-Al target (with purity of (99.99%).) The obtained films were characterized by X-ray diffraction, SEM and optical and electrical measurement... The ZnO-Al films were prepared by R.F. magnetron sputtering system using a Zn-Al target (with purity of (99.99%).) The obtained films were characterized by X-ray diffraction, SEM and optical and electrical measurements. The experimental results show that the properties of ZnO films can be further improved by annealing treatment. The crystallinity of ZnO films becomes better, and the optical gap energy is decreased, but thermoelectric power is enhanced after heat treatment. The optical gap energy decreases from 3.75 eV to 3.68 eV when the annealing temperature increases from 25 ℃ to 400 ℃.This can be ascribed to the decrease of carrier concentration, resulting in Burstein shift. 展开更多
关键词 氧化锌薄膜 退火处理 塞贝克效应 光学能隙 半导体
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基于中国省级面板数据对数字乡村建设促进城乡共同富裕的研究 被引量:3
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作者 丛海彬 黄萍 邹德玲 《湖南师范大学自然科学学报》 CAS 北大核心 2024年第1期84-93,共10页
数字乡村建设是实现城乡共同富裕的重要实践路径。本研究基于2011—2020年我国31个省份的面板数据,构建数字乡村评价指标体系,实证探究了数字乡村建设对城乡共同富裕的影响。研究表明:(1)数字乡村建设有利于收敛城乡收入差距,进而促进... 数字乡村建设是实现城乡共同富裕的重要实践路径。本研究基于2011—2020年我国31个省份的面板数据,构建数字乡村评价指标体系,实证探究了数字乡村建设对城乡共同富裕的影响。研究表明:(1)数字乡村建设有利于收敛城乡收入差距,进而促进共同富裕。(2)异质性结果表明数字乡村建设对东部地区的促进作用更强。(3)机制分析表明非农就业是数字乡村建设促进共同富裕的重要路径。(4)数字乡村建设水平对共同富裕的作用存在空间溢出效应。 展开更多
关键词 数字乡村 共同富裕 城乡收入差距 空间溢出效应
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