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A nano-scale alignment method for imprint lithography

WANG Li, LU Bing-heng, DING Yu-cheng, QIU Zhi-hui, LIU Hong-zhong

《机械工程前沿(英文)》 2006年 第1卷 第2期   页码 157-161 doi: 10.1007/s11465-006-0014-2

摘要: A novel nano-scale alignment technique based on moiré signal for room-temperature imprint lithography in the submicron realm is proposed. The moiré signals generated by two pairs of quadruple gratings on mold and wafer are optically projected onto two photo-detector arrays, then the detected moiré signals are used to estimate the alignment errors in the x and y directions. The experiment results indicate that complex differential moiré signal is sensitive to relative displacement of the mold and wafer, and the alignment accuracy obtained in the x and γ directions and in θ are 20 nm , 25 nm and 1 μrad (3σ), respectively. They can meet the requirements of alignment accuracy for submicron imprint lithography.

关键词: submicron     alignment accuracy     nano-scale alignment     quadruple     room-temperature    

The effect of doping and steam treatment on the catalytic activities of nano-scale H-ZSM-5 in the methanol

Baodong Song, Yongqiang Li, Gang Cao, Zhenhai Sun, Xu Han

《化学科学与工程前沿(英文)》 2017年 第11卷 第4期   页码 564-574 doi: 10.1007/s11705-017-1654-y

摘要: In the transformation of methanol to gasoline (MTG), the selectivity to gasoline and the aromatic content in the produced gasoline are important factors. The catalytic activities of steam-treated and non-steam-treated nano-scale H-ZSM-5 (NHZ5) catalysts impregnated with Ag(I), Zn(II) or P(V) have been investigated in a continuous flow fixed bed reactor. The NH -TPD results showed that after impregnation, the Ag/NHZ5, Zn/NHZ5 and P/NHZ5 catalysts contained comparatively more strong, medium-strong and weak acid sites, respectively. Treatment with steam decreased the number of acid sites in all the catalysts, but the pore volumes in the catalysts were larger which improved carbon deposition resistance resulting in prolonged lifetimes. After 6 h of MTG reaction, the selectivity to gasoline for the steam-treated catalysts, , and were 70.5, 68.4 and 68.7 wt-%, respectively, whereas their respective aromatic contents in the produced gasoline were 61.9, 55.4 and 39.0 wt-%. Thus is the most promising catalyst for MTG applications which can meet the China IV gasoline standard that the amount of aromatics in gasoline should be less than 48 wt-%.

关键词: MTG     nano-scale H-ZSM-5     steam treatment     gasoline     selectivity to gasoline    

基于纳米铁碳析出物的钢综合强化机理

傅杰,李光强,于月光,毛新平,方克明

《中国工程科学》 2011年 第13卷 第1期   页码 31-42

摘要:

简要叙述了关于钢强化机理的研究现状,用化学相分析+X射线小角散射、RTO方法及高分辨透射电镜对薄板坯连铸连轧钛微合金化高强耐候钢中纳米粒子的属性进行了综合分析。发现钛微合金化高强耐候钢中尺寸<36 nm的粒子,除纳米TiC以外,还存在大量的纳米Fe3C,其体积分数为同尺寸TiC体积分数的4.4倍,析出强化作用比纳米TiC粒子大,不可忽略;提出了钢的综合强化机理,指出对不同种类、不同尺寸的纳米析出粒子,应分别根据位错切割和位错绕过机理计算出析出强化贡献,然后与固溶强化和细晶强化贡献加和,求得钢的屈服强度;讨论了细晶强化与位错强化不能加和的原因以及相变对钢强度影响的表现形式, 对钛微合金化高强耐候钢屈服强度的理论计算与生产结果相符,实验钢 σ= 630~676 MPa,实际 σs=630~680 MPa。 简述了钢综合强化机理的应用情况,指出了有待进一步研究的科学问题。

关键词: 屈服强度     纳米铁碳析出物     纳米TiC     析出强化     钢的综合强化机理    

Strengthening of polysulfone membranes using hybrid mixtures of micro- and nano-scale modifiers

Peyman P. Selakjani, Majid Peyravi, Mohsen Jahanshahi, Hamzeh Hoseinpour, Ali S. Rad, Soodabeh Khalili

《化学科学与工程前沿(英文)》 2018年 第12卷 第1期   页码 174-183 doi: 10.1007/s11705-017-1670-y

摘要: Polysulfone (PSf) membranes were modified by either a new organic modifier (sulfonated poly(ether sulfide sulfone), SPESS) or a traditional modifier (rice hulk). These membranes were further reinforced with either multi-walled carbon nanotubes (MWCNTs) or silica nanoparticles. Having a dye rejection of 98.46%, the reinforced membranes increased more than 50% in strength but no change in solution flux was observed. The morphological and roughness studies were conducted using scanning electron microscopy and atomic force microscopy. Moreover, the PSF membranes were also characterized by differential scanning calorimetry. Modifying the membranes with organic modifier or nanofiller increases the glass transition temperature ( ). The highest and strength were observed for the PSf-SPESS-MWCNT membrane. SPESS decreases surface roughness but MWCNT increases roughness on the nanoscale. All membranes show a bimodal pore size distribution, whereas the PSf-SPESS-MWCNT membrane exhibits a relatively uniform distribution of macroscopic and microscopic pores.

关键词: polysulfone membrane     mechanical properties     micro- and nano-modification     binary and ternary system     dye removal    

典型纳米结构制备及其测量表征

蒋庄德,王琛英,杨树明

《中国工程科学》 2013年 第15卷 第1期   页码 15-20

摘要:

针对纳米器件中的典型几何特征,制备了3种纳米结构,采用扫描电子显微镜(SEM)、原子力显微镜(AFM)等测量工具对所制备的纳米样板进行了测量、分析和表征。提出转换薄膜厚度为线宽的公称值、基于多层薄膜淀积技术制备纳米宽度结构的方法,制备出了具有名义线宽尺寸分别为20 nm、25 nm、35 nm的纳米栅线结构。用离线的图像分析算法对所制备的纳米线宽样板的线边缘粗糙度/线宽粗糙度(LER/LWR)以及栅线线宽的一致性进行了评估。实验表明所制备纳米线宽样板的栅线具有较好的一致性,LER/LWR值小,且具有垂直的侧壁。采用电子束直写技术(EBL)和感应耦合等离子体刻蚀(ICP)制备了名义高度为220 nm的硅台阶样板。实验表明刻蚀后栅线边缘LER/LWR的高频成分减少,相关长度变长,均方根偏差值(σ)增大。采用聚焦离子束(FIB)制备了纳米单台阶和多台阶结构,并对Z方向的尺度与加工能量之间的关系进行了分析。

关键词: 纳米栅线     纳米台阶     EBL     ICP     FIB    

Achievements and trends of solid oxide fuel cells in clean energy field: a perspective review

Abdalla M. ABDALLA, Shahzad HOSSAIN, Pg MohdIskandr PETRA, Mostafa GHASEMI, Abul K. AZAD

《能源前沿(英文)》 2020年 第14卷 第2期   页码 359-382 doi: 10.1007/s11708-018-0546-2

摘要: The main concerns in the world today, especially in the energy field, are subjected to clean, efficient, and durable sources of energy. These three aspects are the main goals that scientist are paying attention to. However, the various types of energy resources include fossil and sustainable ones, but still some challenges are chasing these kinds from energy conversion, storage, and efficiency. Hence, the most reliable and considered energy resource nowadays is the utilized one which is as highly efficient, clean, and everlasting as possible. So, in this review, an attempt is made to highlight one of the promising types as a clean and efficient energy resource. Solid oxide fuel cell (SOFC) is the most efficient type of the fuel cell types involved with hydrogen and hydrocarbon-based fuels, especially when it works with combined heat and power (CHP). The importance of this type is due to its nature of work as conversion tool from chemical to electrical for generation of power without noise, pollution, and can be safely handled.

关键词: solid oxide fuel cells (SOFCs)     clean energy     design     micro-scale     nano-scale     performance    

Three-scale stochastic homogenization of elastic recycled aggregate concrete based on nano-indentation

Chen WANG, Yuching WU, Jianzhuang XIAO

《结构与土木工程前沿(英文)》 2018年 第12卷 第4期   页码 461-473 doi: 10.1007/s11709-017-0441-7

摘要: In this paper, three-scale stochastic elastic finite element analyses are made for recycled aggregate concrete (RAC) based on nano-indentation digital images. The elastic property of RAC contains uncertainties across scales. It has both theoretical and practical values to model and predict its mechanical performance. Based on homogenization theory, effective stochastic elastic moduli of RAC at three different scales are obtained using moving window technique, nano-indentation digital images, and Monte-Carlo method. It involves the generation of a large number of random realizations of microstructure geometry based on different volume fraction of the inclusions and other parameters. The mean value, coefficient of variation and probability distribution of the effective elastic moduli are computed considering the material multiscale structure. The microscopic randomness is taken into account, and correlations of RAC among five phases are investigated. The effective elastic properties are used to obtain the global behavior of a composite structure. It is indicated that the response variability can be considerably affected by replacement percentage of recycled aggregates.

关键词: RAC     nano-indentation digital image     multiscale     microscopic randomness     homogenization    

Remediation of 2,4-dichlorophenol-contaminated groundwater using nano-sized CaO in a two-dimensionalscale tank

《环境科学与工程前沿(英文)》 2020年 第15卷 第5期 doi: 10.1007/s11783-020-1381-3

摘要:

• Nano CaO2 is evaluated as a remediation agent for 2,4-DCP contaminated groundwater.

关键词: Calcium peroxide     2     4-DCP     Reaction zone     Fenton reaction    

Laser vision sensing based on adaptive welding for aluminum alloy

CHEN Zhixiang, SONG Yonglun, ZHANG Jun, ZHANG Wanchun, JIANG Li, XIA Xuxin

《机械工程前沿(英文)》 2007年 第2卷 第2期   页码 218-223 doi: 10.1007/s11465-007-0038-2

摘要: A laser vision sensing based on the adaptive tungsten inert gas (TIG) welding system for large-scale aluminum alloy components was established to fit various weld groove conditions. A new type of laser vision sensor was used to precisely measure the weld groove. The joint geometry data, such as the bevel angle, the gap, the area, and the mismatch, etc., aided in assembling large-scale aerospace components before welding. They were also applied for automatic seam tracking, such as automatic torch transverse alignment and torch height adjustment in welding. An adaptive welding process was realized by automatically adjusting the wire feeding speed and the welding current according to the groove conditions. The process results in a good weld formation and high welding quality, which meet the requirements of related standards.

关键词: adjustment     adaptive tungsten     transverse alignment     large-scale aluminum     geometry    

Coordinated shift control of nonsynchronizer transmission for electric vehicles based on dynamic tooth alignment

《机械工程前沿(英文)》 2021年 第16卷 第4期   页码 887-900 doi: 10.1007/s11465-021-0653-3

摘要: Multispeed transmissions can enhance the dynamics and economic performance of electric vehicles (EVs), but the coordinated control of the drive motor and gear shift mechanism during gear shifting is still a difficult challenge because gear shifting may cause discomfort to the occupants. To improve the swiftness of gear shifting, this paper proposes a coordinated shift control method based on the dynamic tooth alignment (DTA) algorithm for nonsynchronizer automated mechanical transmissions (NSAMTs) of EVs. After the speed difference between the sleeve (SL) and target dog gear is reduced to a certain value by speed synchronization, angle synchronization is adopted to synchronize the SL quickly to the target tooth slot’s angular position predicted by the DTA. A two-speed planetary NSAMT is taken as an example to carry out comparative simulations and bench experiments. Results show that gear shifting duration and maximum jerk are reduced under the shift control with the proposed method, which proves the effectiveness of the proposed coordinated shift control method with DTA.

关键词: electric vehicle     nonsynchronizer automated mechanical transmission (NSAMT)     planetary gear     coordinated shift control     dynamic tooth alignment    

基于对齐自修正的鲁棒跨模态检索 Research Article

郭金一1,丁洁玉2

《信息与电子工程前沿(英文)》 2023年 第24卷 第10期   页码 1403-1415 doi: 10.1631/FITEE.2200514

摘要: 跨模态检索通过为不同模态数据建立一致的对齐方式来实现模态间的相互检索。目前多种跨模态检索方法已被提出并取得良好性能。这些方法使用干净对齐的跨模态数据进行训练。虽然这些数据在语义上是匹配的,但相较于互联网上容易获得的噪声对齐的数据(即成对但在语义上不匹配),标注成本很高。当用噪声对齐的数据训练这些模型时,它们的性能会急剧下降。因此,本文提出一种对齐自修正的鲁棒跨模态检索算法(RCAR),显著降低了噪声数据对模型的影响。具体来说,RCAR首先进行多任务学习,减缓模型对噪声数据的过拟合,使数据分离。然后,利用两成分的贝塔混合模型将数据分为干净数据和噪声数据,并根据后验概率修正对齐标签。此外,在噪声对齐范式中定义两种噪声类型:部分噪声数据和完全噪声数据。实验结果表明,与当下流行的跨模态检索方法相比,RCAR在两种类型的噪声下都能取得更稳健的性能。

关键词: 跨模态检索;鲁棒学习;对齐修正;贝塔混合模型    

微分和表观静摩擦系数的表式

王渭源

《中国工程科学》 2001年 第3卷 第8期   页码 29-32

摘要:

当前,工程师和科学家都对微牛和纳牛量级载荷静摩擦系数(以下简称微牛纳牛静摩擦系数)很感兴趣。但文献中至今没有详细讨论过微牛纳牛静摩擦系数与载荷的关系,而且发表的实验结果都不相互讨论。从微分静摩擦系数的定义出发,导出几种典型模型下微分静摩擦系数和表观静摩擦系数的表式,并据此广泛讨论这些文献中的实验结果。

关键词: 微分静摩擦系数     微牛纳牛静摩擦系数     表观静摩擦系数     宏观静摩擦系数    

Water-dispersible nano-pollutions reshape microbial metabolism in type-specific manners: A metabolic

《环境科学与工程前沿(英文)》 2022年 第16卷 第9期 doi: 10.1007/s11783-022-1548-1

摘要:

• Water-dispersible nano-pollutions exhibit type-specific toxic effects on E. coli.

关键词: Nano-toxicity     Nano-plastics     Quantum dots     Microbial metabolite     Metabolic dysregulation    

Laboratory investigation of emulsified asphalt binder modified with wood-derived nano-cellulose and nano

Yunge WEI; Jiayu WANG; Ruoyu LI; Ling XU; Feipeng XIAO

《结构与土木工程前沿(英文)》 2022年 第16卷 第11期   页码 1474-1485 doi: 10.1007/s11709-022-0869-2

摘要: Emulsified asphalt is the primary material for preventive maintenance and cold-mix paving, but its low cohesive strength and poor mechanical properties limit its wide application, even with polymer modification. In this study, Styrene-Butadiene Rubber (SBR) emulsified asphalt was modified with nano-cellulose materials, namely nano paper-cellulose (NPC) and wood-derived nano-cellulose (WDC), to improve its properties. A novel preparation method of nano-cellulose solution was developed, including blending, ultrasonic stirring, and centrifugal treatment. Four types of nano-cellulose solution (0.5% NPC, 0.5%, 1.0%, and 1.5% WDC by weight of water) were selected. The microscopy analysis indicated that 0.5% WDC emulsion had a smaller particle size than 1.5% WDC emulsion. The rheology test indicated that WDC modified residue improved rutting resistance with the increased solution dosage due to the cross-linking effect, but its creep-and-recovery performance was worse than that of SBR emulsion residue. The NPC modified binder had a higher rutting factor than WDC modified binder at the same dosage after short-term aging. In addition, 1.0% WDC could be regarded as the optimal dosage in terms of fatigue and low-temperature performance. Furthermore, Fourier Transform Infrared Spectroscopy (FTIR) results showed that 0.5% NPC modified residue performed better in long-term aging resistance compared with 0.5%WDC modified asphalt.

关键词: nano-cellulose     emulsified asphalt binder     dispersion     rheological properties     Fourier transform infrared spectroscopy    

标题 作者 时间 类型 操作

A nano-scale alignment method for imprint lithography

WANG Li, LU Bing-heng, DING Yu-cheng, QIU Zhi-hui, LIU Hong-zhong

期刊论文

The effect of doping and steam treatment on the catalytic activities of nano-scale H-ZSM-5 in the methanol

Baodong Song, Yongqiang Li, Gang Cao, Zhenhai Sun, Xu Han

期刊论文

基于纳米铁碳析出物的钢综合强化机理

傅杰,李光强,于月光,毛新平,方克明

期刊论文

Strengthening of polysulfone membranes using hybrid mixtures of micro- and nano-scale modifiers

Peyman P. Selakjani, Majid Peyravi, Mohsen Jahanshahi, Hamzeh Hoseinpour, Ali S. Rad, Soodabeh Khalili

期刊论文

典型纳米结构制备及其测量表征

蒋庄德,王琛英,杨树明

期刊论文

Achievements and trends of solid oxide fuel cells in clean energy field: a perspective review

Abdalla M. ABDALLA, Shahzad HOSSAIN, Pg MohdIskandr PETRA, Mostafa GHASEMI, Abul K. AZAD

期刊论文

Three-scale stochastic homogenization of elastic recycled aggregate concrete based on nano-indentation

Chen WANG, Yuching WU, Jianzhuang XIAO

期刊论文

Remediation of 2,4-dichlorophenol-contaminated groundwater using nano-sized CaO in a two-dimensionalscale tank

期刊论文

Laser vision sensing based on adaptive welding for aluminum alloy

CHEN Zhixiang, SONG Yonglun, ZHANG Jun, ZHANG Wanchun, JIANG Li, XIA Xuxin

期刊论文

Coordinated shift control of nonsynchronizer transmission for electric vehicles based on dynamic tooth alignment

期刊论文

基于对齐自修正的鲁棒跨模态检索

郭金一1,丁洁玉2

期刊论文

微分和表观静摩擦系数的表式

王渭源

期刊论文

王建国:负载型纳米催化剂的多尺度模拟(2019年5月25日)

2021年04月22日

会议视频

Water-dispersible nano-pollutions reshape microbial metabolism in type-specific manners: A metabolic

期刊论文

Laboratory investigation of emulsified asphalt binder modified with wood-derived nano-cellulose and nano

Yunge WEI; Jiayu WANG; Ruoyu LI; Ling XU; Feipeng XIAO

期刊论文