期刊文献+
共找到15篇文章
< 1 >
每页显示 20 50 100
利用阳极化处理铝的大面积栅式场发射阵列(FEAs)
1
作者 卢有祥 《光电技术》 2001年第3期44-48,53,共6页
本文报道了一种用非光刻技术生产栅式场发射阵列铝膜的新方法。用此方法,生产出了轮廓分明的多孔阳极化处理的铝层,用于生产密度很高的场发射体(≈5×10∧8/cm∧2),小尺寸单个发射体器件的优点就是能够在较低的引出电压下工作... 本文报道了一种用非光刻技术生产栅式场发射阵列铝膜的新方法。用此方法,生产出了轮廓分明的多孔阳极化处理的铝层,用于生产密度很高的场发射体(≈5×10∧8/cm∧2),小尺寸单个发射体器件的优点就是能够在较低的引出电压下工作。能够观察到发光的最低引出电压为15V。发射体阵列含有大约20000个发射体,可获得高达30mA/cm∧2的电流密度(在50V激励电压下),最近的结果表明其性能适合作显示器件,这一技术在制作大面积、低成本的显示器件方面具有潜力。 展开更多
关键词 场发射体阵列 非光刻发射体制造 多孔阳极化处理
下载PDF
鸮翼后缘噪声的预测及控制 被引量:6
2
作者 葛长江 叶辉 +1 位作者 胡兴军 于征磊 《吉林大学学报(工学版)》 EI CAS CSCD 北大核心 2016年第6期1981-1986,共6页
基于鸮翼的仿生翼型可用于揭示鸮翼的噪声产生机理。通过大涡模拟给出仿生翼型的流场,从中发现由前缘分离引起的两个声源分别为再附着的湍流边界层和从气泡中分离出来的涡脱落。由此可知,低雷诺数下的鸮翼宽频噪声是由湍流边界层散射导... 基于鸮翼的仿生翼型可用于揭示鸮翼的噪声产生机理。通过大涡模拟给出仿生翼型的流场,从中发现由前缘分离引起的两个声源分别为再附着的湍流边界层和从气泡中分离出来的涡脱落。由此可知,低雷诺数下的鸮翼宽频噪声是由湍流边界层散射导致的。之后,将被动多孔技术用于仿生翼型的后缘,在静压场中证实了多孔后缘缓解瞬态压力变化的作用。相关的噪声频谱也表明,多孔后缘具有高达10dB以上的降噪潜力,但是降噪的幅度依赖于流阻率。 展开更多
关键词 工程仿生学 仿生翼型 涡脱落 湍流边界层 多孔处理 后缘降噪
下载PDF
A Novel Technology for Post-Treating of Porous Silicon Thick Films in H_2O_2
3
作者 龙永福 朱自强 赖宗声 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2003年第6期574-578,共5页
The solution of H 2O 2 is proposed to post-treat thick porous silicon (PS) films.The prepared PS film as the cathode is applied about 10mA/cm 2 current in mixture of ethanol,HF,and H 2O 2 solutions,which is expec... The solution of H 2O 2 is proposed to post-treat thick porous silicon (PS) films.The prepared PS film as the cathode is applied about 10mA/cm 2 current in mixture of ethanol,HF,and H 2O 2 solutions,which is expected to improve the stability and the smoothness of the surface and the mechanical property of the thick porous silicon films.The microstructure of the PS thick films with thicknesse of 20μm and 70μm has been studied.The SEM images show significant improved smoothness on surface of PS films,and XRD spectra suggest the formation of oxide layer after post-treating in H 2O 2. 展开更多
关键词 porous silicon POST-TREATMENT H 2O 2
下载PDF
Ag Deposition Forms and Uniformity on Porous Silicon by Electrochemical Method 被引量:1
4
作者 宋晓岚 徐大余 +2 位作者 杨海平 喻振兴 邱冠周 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2010年第2期211-216,I0002,共7页
The electrochemical deposition technique was applied to achieve porous silicon (PS) surface passivated with Ag deposition for improving the properties of PS photoluminescence. The relation of Ag depositing forms to ... The electrochemical deposition technique was applied to achieve porous silicon (PS) surface passivated with Ag deposition for improving the properties of PS photoluminescence. The relation of Ag depositing forms to current density and the effect of PS hydrophilic surface on deposition uniformity were investigated. The experimental results indicated that there were two critical current densities (maximum and minimum) in which Ag was absent and electroplated on PS surface correspondingly, and the range of current density for deposition of Ag on porous silicon was from 50 μA/cm^2 to 400 μA/cm^2. The process of changing PS surface from hydrophobic into hydrophilic had positive effect on Ag deposition uniformity. Under the same experimental conditions, PS hydrophobic surface presented uneven Ag deposition.However, hydrophilic surface treated with SC-1 solution was even. Finally, the effect of PS surface passivation with Ag even deposition on photoluminescence intensity and stabilization of PS was studied. It was discovered that Ag passivation inhibited the degradation of PL intensity effectively. In addition, excessive Ag deposition had a quenching effect on room-temperature visible photoluminescence of PS. 展开更多
关键词 Porous silicon Photoluminescence Hydrophilic process Ag deposition Passivation
下载PDF
Effects of alkali and heat treatment on strength of porous Ti35Nb
5
作者 万小军 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第6期1335-1339,共5页
Porous Ti35Nb alloy with a porosity of 66% was made by a powder metallurgical method, and then it was treated by a standard treatment for activating the surface of Ti implant materials involving alkali and heat treatm... Porous Ti35Nb alloy with a porosity of 66% was made by a powder metallurgical method, and then it was treated by a standard treatment for activating the surface of Ti implant materials involving alkali and heat treatment. The alkali and heat treatment causes damages of the struts of the porous Ti35Nb in the form of reaction products layer, grain-pullout and cracks. Consequently, it leads to a significant degradation of the strength of the porous alloy. The effect of the alkali and heat treatment on the strength of the porous alloy was discussed. 展开更多
关键词 porous Ti-Nb alloy mechanical property alkali treatment
下载PDF
Enhanced MTO performance over acid treated hierarchical SAPO-34 被引量:25
6
作者 Shu Ren Guojuan Liu +5 位作者 Xian Wu Xinqing Chen Minghong Wu Gaofeng Zeng Ziyu Liu Yuhan Sun 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2017年第1期123-130,共8页
Hierarchical SAPO‐34 crystals were synthesized by a facile acid etching post‐treatment. Butterfly‐shaped porous patterns on four side faces and hierarchical pores composed of micropores,mesopores and macropores wer... Hierarchical SAPO‐34 crystals were synthesized by a facile acid etching post‐treatment. Butterfly‐shaped porous patterns on four side faces and hierarchical pores composed of micropores,mesopores and macropores were formed after a nitric acid or oxalic acid treatment. The catalyticperformance of the hierarchical SAPO‐34 for the methanol to olefins (MTO) process showed that thesynergistic effect of the hierarchical pores and acid sites resulted in a longer catalyst lifetime (from210 to 390 min for the acid treated SAPO‐34) and higher selectivity to light olefins of 92%–94%.The ethylene selectivity can be adjusted between 37.4% and 51.5% by the pore size. No hierarchical SAPO‐34 was obtained after a treatment with butanedioic acid, and with this sample, fast deactivation was detected after 100 min. 展开更多
关键词 Acid treatment Hierarchical pore SAPO‐34 Methanol to olefins Single‐run lifetime
下载PDF
Effect of heat treatment of Mn-Cu precursors on morphology of dealloyed nanoporous copper 被引量:3
7
作者 TAN Xiu-lan LI Kai +6 位作者 NIU Gao YI zao LUO Jiang-shan LIU Ying HAN shan-jun WU Wei-dong TANG Yong-jian 《Journal of Central South University》 SCIE EI CAS 2012年第1期17-21,共5页
Nanoporous copper with nano-scale pore size was synthesized by dealloying Mn-Cu precursor alloy using a free corrosion method. The effects of heat treatment of Mn-Cu precursors on alloy phase, morphology and compositi... Nanoporous copper with nano-scale pore size was synthesized by dealloying Mn-Cu precursor alloy using a free corrosion method. The effects of heat treatment of Mn-Cu precursors on alloy phase, morphology and composition of the resultant nanoporous copper were investigated. It is revealed that the compositions distribute homogeneously in the bulk Mn-Cu precursors, which consequently results in a more fully dealloying for forming nanoporous copper. The alloy phase changes from Cuo.a9Mno.51 and Cuo.21Mno.79 of non-thermally treated precursor to Cuo.33Mn0.67 of heat treated alloy. The residual Mn content in nanoporous copper is decreased from 12.97% to 2.04% (molar fraction) made from the precursor without and with 95 h heat treatment. The typical pore shape of nanoporous copper prepared by dealloying the precursor without the heat treatment is divided into two different zones: the uniform bi-continuous structure zone and the blurry or no pore structure zone. Nanoporous copper is of a uniform sponge-like morphology made from the heat-treated precursor, and the average ligament diameter is 40 nm, far smaller than that from the non-thermally treated precursor, in which the average ligament diameter is estimated to be about 70 nm. 展开更多
关键词 nanoporous copper PREPARATION DEALLOYING heat treatment MORPHOLOGY
下载PDF
C-I codoped porous g-C_3N_4 for superior photocatalytic hydrogen evolution 被引量:8
8
作者 Chuanfeng Yang Wei Teng +1 位作者 Yanhua Song Yanjuan Cui 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第10期1615-1624,共10页
Porous C‐I codoped carbon nitride materials were synthesized by in‐situ codoping with iodized ionic liquid followed by post‐thermal treatment in air.The effects of doping content of C‐I codoping with different amo... Porous C‐I codoped carbon nitride materials were synthesized by in‐situ codoping with iodized ionic liquid followed by post‐thermal treatment in air.The effects of doping content of C‐I codoping with different amounts of ionic liquid on the structural,optical and photocatalytic properties of the samples were investigated.Characterization results show that more compact interlayer sacking can be achieved by post‐thermal treatment.Combined with C‐I codoping by insertion of ionic liquids,much enlarged surface area but optimized sp2 conjugated heterocyclic structure can be found in the catalysts.Optical and energy band analysis results evidence that the light absorptions especially in visible light region are significantly improved.Although the band gap of porous C‐I codoped samples enlarge because of the generation of porous,the negatively shifted conduction band position thermodynamically supplies stronger motivation for water reduction.Photoelectricity tests reveal that the photo‐induced electron density was increased after C‐I codoping modification.Also,the recombination rate of electron‐hole pairs is remarkably inhibited.The catalysts with moderate C‐I codoing content perform sharply enhanced photocatalytic H2 evolution activity under visible light irradiation.A H2 evolution rate of 168.2μmol/h was achieved and it was more than 9.8 times higher than pristine carbon nitride.This study demonstrates a novel non‐metal doping strategy for synthesis and optimization of polymer semiconductor with gratifying photocatalytic H2 evolution performance from water hydrolysis. 展开更多
关键词 Porous carbon nitride C‐I codoping Post‐thermal treatment PHOTOCATALYSIS H2 evolution
下载PDF
Facile Synthesis of 3D Porous Flower-like ZnO Micro/nanostructure Films and Their Photocatalytic Performance
9
作者 Jin-ling Yang Guang Tao +2 位作者 Fei Hui Li Hao-miao Ouyang 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2012年第3期339-344,374,共7页
3D porous flower-like ZnO micro/nanostructure films grown on Ti substrates are synthesized via a very facile electrodeposition technique followed by heat treatment process. The ZnO architecture is assembled with ultra... 3D porous flower-like ZnO micro/nanostructure films grown on Ti substrates are synthesized via a very facile electrodeposition technique followed by heat treatment process. The ZnO architecture is assembled with ultra thin sheets, which consist of numbers of nanoparticles and pores, and the size of the nanoparticles can be controlled by adjusting the electrodepo- sition time or calcination temperature. It is worth noting that this synthetic method can provide an effective route for other porous metal oxide nanostructure films. Moreover, the photocatalytic performance shows the porous ZnO is an ideal photocatalyst. 展开更多
关键词 Zinc oxide porous film PHOTOCATALYST MICRO/NANOSTRUCTURE ELECTRODEPOSITION
下载PDF
化学处理对混凝土中聚丙烯纤维加固效果的影响
10
作者 房海棠 颜婷婷 赵超 《上海纺织科技》 北大核心 2018年第9期32-35,共4页
通过对聚丙烯(PP)纤维进行多孔化处理及聚醋酸乙烯酯(PVAC)涂层,按不同配比掺入水泥基砂浆制得复合材料,进而探究改性处理对纤维增强水泥基复合材料力学性能的影响。结果表明:当Br2+H2O体积浓度为5 mL/L、PVAC涂层处理5 s、纤维... 通过对聚丙烯(PP)纤维进行多孔化处理及聚醋酸乙烯酯(PVAC)涂层,按不同配比掺入水泥基砂浆制得复合材料,进而探究改性处理对纤维增强水泥基复合材料力学性能的影响。结果表明:当Br2+H2O体积浓度为5 mL/L、PVAC涂层处理5 s、纤维掺量为0.7 kg/m^3、PP纤维长度为9 mm时,用其制得的复合材料力学性能最好。 展开更多
关键词 复合材料 聚丙烯纤维 涂层处理 聚醋酸乙烯酯 多孔处理 纤维增强 水泥砂浆
原文传递
Pd embedded in porous carbon (Pd@CMK-3) as an active catalyst for Suzuki reactions: Accelerating mass transfer to enhance the reaction rate 被引量:7
11
作者 Zhencai Wang Wei Chen +6 位作者 Zhenliang Han Jie Zhu Na Lu Yun Yang Dekun Ma Ying Chen Shaoming Huang 《Nano Research》 SCIE EI CAS CSCD 2014年第9期1254-1262,共9页
Heterogeneous catalysts are promising candidates for use in organic reactions due to their advantages in separation, recovery, and environment compatibility. In this work, an active porous catalyst denoted as Pd embed... Heterogeneous catalysts are promising candidates for use in organic reactions due to their advantages in separation, recovery, and environment compatibility. In this work, an active porous catalyst denoted as Pd embedded in porous carbon (Pd@CMK-3) has been prepared by a strategy involving immersion, ammonia- hydrolysis, and heating procedures. Detailed characterization of the catalyst revealed that Pd(0) and Pd(I1) species co-exist and were embedded in the matrix of the porous carbon (CMK-3). The as-prepared catalyst has shown high activity toward Suzuki reactions. Importantly, if the reaction mixture was homogenized by two minutes of ultrasonication rather than magnetic stirring before heating, the resistance to mass transfer in the pore channels was significantly reduced. As a result, the reactions proceeded more rapidly and a four-fold increase in the turnover frequency (TOF) could be obtained. When the ultrasonication was employed throughout the entire reaction process, the conversion could also exceed 90% even without the protection of inert gas, and although the reaction temperature was lowered to 30 ℃. This work provides a method for fabricating highly active porous carbon encapsulated Pd catalysts for Suzuki reactions and proves that the problem of mass transfer in porous catalysts can be conveniently resolved by ultrasonication without any chemical modification being necessary. 展开更多
关键词 PD CMK-3 porous catalyst Suzuki reactions mass transfer
原文传递
Preparation and bioactive surface modification of the microwave sintered porous Ti-15Mo alloys for biomedical application 被引量:5
12
作者 Jilin Xu Jinlong Zhang +3 位作者 Luzi Bao Tao Lai Junming Luo Yufeng Zheng 《Science China Materials》 SCIE EI CSCD 2018年第4期545-556,共12页
Biomedical porous Ti-15 Mo alloys were prepared by microwave sintering using ammonium hydrogen carbonate(NH4HCO3) as the space holder agent to adjust the porosity and mechanical properties. The porous Ti-15 Mo alloy... Biomedical porous Ti-15 Mo alloys were prepared by microwave sintering using ammonium hydrogen carbonate(NH4HCO3) as the space holder agent to adjust the porosity and mechanical properties. The porous Ti-15 Mo alloys are dominated by β-Ti phase with a little α-Ti phase, and the proportion of α and β phase has no significant difference as the NH4HCO3 content increases. The porosities and the average pore sizes of the porous Ti-15 Mo alloys increase with increase of the contents of NH4HCO3, while all of the compressive strength, elastic modulus and bending strength decrease. However, the compressive strength, bending strength and the elastic modulus are higher or close to those of natural bone. The surface of the porous Ti-15 Mo alloy was further modified by hydrothermal treatment, after which Na2Ti6O13 layers with needle and flake-like clusters were formed on the outer and inner surface of the porous Ti-15 Mo alloy. The hydrothermally treated porous Ti-15 Mo alloy is completely covered by the Ca-deficient apatite layers after immersed in SBF solution for 14 d, indicating that it possesses high apatiteforming ability and bioactivity. These results demonstrate that the hydrothermally treated microwave sintered porous Ti-15 Mo alloys could be a promising candidate as the bone implant. 展开更多
关键词 porous Ti-15Mo alloy microwave sintering hydrothermal treatment apatite-forming ability mechanical property
原文传递
Comprehensive Approach for Porous Materials Analysis Using a Dedicated Preprocessing Tool for Mass and Heat Transfer Modeling 被引量:8
13
作者 MADEJSKI Pawel KRAKOWSKA Paulina +2 位作者 HABRAT Magdalena PUSKARCZYK Edyta JEDRYCHOWSKI Mariusz 《Journal of Thermal Science》 SCIE EI CAS CSCD 2018年第5期479-486,共8页
The paper presents a comprehensive, newly developed software – poROSE(poROus materials examination SoftwarE) for the qualitative and quantitative assessment of porous materials and analysis methodologies developed by... The paper presents a comprehensive, newly developed software – poROSE(poROus materials examination SoftwarE) for the qualitative and quantitative assessment of porous materials and analysis methodologies developed by the authors as a solution for emerging challenges. A low porosity rock sample was analyzed and thanks to the developed and implemented methodologies in poROSE software, the main geometrical properties were calculated. A tool was also used in preprocessing part of the computational analysis to prepare a geometrical representation of the porous material. The basic functions as elimination of blind pores in the geometrical model were completed and the geometrical model was exported for CFD software. As a result, it was possible to carry out calculations of the basic properties of the analyzed porous material sample. The developed tool allows to carry out quantitative and qualitative analysis to determine the most important properties characterized porous materials. In presented tool the input data can be images from X-ray computed tomography(CT), scanning electron microscope(SEM) or focused ion beam with scanning electron microscope(FIB-SEM) in grey level. A geometric model developed in the proper format can be used as an input to modeling mass, momentum and heat transfer, as well as, in strength or thermo-strength analysis of any porous materials. In this example, thermal analysis was carried out on the skeleton of rock sample. Moreover, thermal conductivity was estimated using empirical equations. 展开更多
关键词 porous materials ROCK SOFTWARE thermal properties PREPROCESSING
原文传递
An oxidation-nitridation-denitridation approach to transform metal solids into foams with adjustable pore sizes for energy applications
14
作者 Hao Qin Chao Zhen +4 位作者 Chunxu Jia Zhiqing Yang Hengqiang Ye Hui-Ming Cheng Gang Liu 《Science Bulletin》 SCIE EI CSCD 2021年第15期1525-1532,M0003,共9页
Metal foams with hierarchically porous structures are highly desirable in energy applications as active materials or their host substrates.However,conventional preparation methods usually have a quite limited flexibil... Metal foams with hierarchically porous structures are highly desirable in energy applications as active materials or their host substrates.However,conventional preparation methods usually have a quite limited flexibility of adjusting pore size of metal foams.Herein,an alternative new method based on gaseous thermal oxidation-nitridation-denitridation processes was developed to prepare metal(copper and nickel)foams with adjustable pore size by controlling the thermal nitridation temperature.Moreover,this environment-friendly method is independent of the shape of starting pure metal substrates and can be repeatedly applied to the metal substrates to create hierarchical porous structures containing different size pores.As a demonstration of the advantages of the resultant foams with abundant pores by this method,compared with its starting material(commercial Ni foam with the pore size of several millimeters),the resultant hierarchical porous Ni foam gives the remarkably enhanced performance of electrochemical water splitting as HER/OER electrodes and electrochemical energy storage as the host substrate of capacitive material MnO2.The metal foams with adjustable pore size prepared by the developed method will find a wide range of important applications in energy storage and conversion areas. 展开更多
关键词 Metal foams Hierarchically porous structures Electrocatalytic water splitting SUPERCAPACITOR
原文传递
Improved conversion efficiency of dye-sensitized solar cells by using novel complex nanostructured TiO_2 electrodes
15
作者 ZHANG TianShu LIU LiFeng +2 位作者 YANG Fei WANG Yi KANG JinFeng 《Science China(Technological Sciences)》 SCIE EI CAS 2013年第1期115-119,共5页
A novel complex nanostructured TiO2 electrode and fabrication process were proposed and demonstrated to improve the performance of dye-sensitized solar cells(DSSCs).In the proposed process,a nanoporous TiO2 layer was ... A novel complex nanostructured TiO2 electrode and fabrication process were proposed and demonstrated to improve the performance of dye-sensitized solar cells(DSSCs).In the proposed process,a nanoporous TiO2 layer was firstly fabricated on the FTO(fluorine-doped tin oxide) conducting substrate by an anodization process,then a nanoparticulate TiO2 film was deposited on the nanoporous TiO2 layer by the screen printed method to form the complex nanostructured TiO2 electrode.The experiments demonstrated that the nanoporous TiO layer can enhance the light scattering,decrease the contact resistance between TiO2 electrode and FTO,and suppress the recombination of I3-ion with the injected electrons of FTO.The process variables are crucial to obtain the optimized performance of DSSCs.By adopting the optimized process,improved conversion efficiency of DSSCs was achieved at AM 1.5 sunlight. 展开更多
关键词 dye-sensitized solar cells conversion efficiency nanoporous TiO2 electrode anodization
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部