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Two-dimensional self-assembly of melem and melemium cations at pH-controlled aqueous solution–Au(111) interfaces under electrochemical control

Shinobu Uemura,Kenki Sakata,Masashi Aono,Yusuke Nakamura,Masashi Kunitake

《化学科学与工程前沿(英文)》 2016年 第10卷 第2期   页码 294-300 doi: 10.1007/s11705-016-1564-4

摘要: Two-dimensional self-assembly of melem at pH-controlled aqueous solution-Au(111) interfaces has been investigated by electrochemical scanning tunneling microscopy. In the solutions with pH>p of melem, two ordered self-assembled structures (honeycomb and close-packed structures) and one disordered fibrillar structure were observed as a function of the surface coverage of melem controlled by the electrode potential. In contrast, in the acidic solution with pH

关键词: self-assembly     scanning tunneling microscopy     electrochemistry     structural phase transition     melem    

Review: Tip-based vibrational spectroscopy for nanoscale analysis of emerging energy materials

Amun JARZEMBSKI, Cedric SHASKEY, Keunhan PARK

《能源前沿(英文)》 2018年 第12卷 第1期   页码 43-71 doi: 10.1007/s11708-018-0524-8

摘要: Vibrational spectroscopy is one of the key instrumentations that provide non-invasive investigation of structural and chemical composition for both organic and inorganic materials. However, diffraction of light fundamentally limits the spatial resolution of far-field vibrational spectroscopy to roughly half the wavelength. In this article, we thoroughly review the integration of atomic force microscopy (AFM) with vibrational spectroscopy to enable the nanoscale characterization of emerging energy materials, which has not been possible with far-field optical techniques. The discussed methods utilize the AFM tip as a nanoscopic tool to extract spatially resolved electronic or molecular vibrational resonance spectra of a sample illuminated by a visible or infrared (IR) light source. The absorption of light by electrons or individual functional groups within molecules leads to changes in the sample’s thermal response, optical scattering, and atomic force interactions, all of which can be readily probed by an AFM tip. For example, photothermal induced resonance (PTIR) spectroscopy methods measure a sample’s local thermal expansion or temperature rise. Therefore, they use the AFM tip as a thermal detector to directly relate absorbed IR light to the thermal response of a sample. Optical scattering methods based on scanning near-field optical microscopy (SNOM) correlate the spectrum of scattered near-field light with molecular vibrational modes. More recently, photo-induced force microscopy (PiFM) has been developed to measure the change of the optical force gradient due to the light absorption by molecular vibrational resonances using AFM’s superb sensitivity in detecting tip-sample force interactions. Such recent efforts successfully breech the diffraction limit of light to provide nanoscale spatial resolution of vibrational spectroscopy, which will become a critical technique for characterizing novel energy materials.

关键词: vibrational spectroscopy     atomic force microscopy     photo-thermal induced resonance     scanning near-field optical microscopy     tip-enhanced Raman spectroscopy     photo-induced force microscopy     molecular resonances     surface phonon polaritons     energy materials    

Experimental flexural behavior of SMA-FRP reinforced concrete beam

Adeel ZAFAR, Bassem ANDRAWES

《结构与土木工程前沿(英文)》 2013年 第7卷 第4期   页码 341-355 doi: 10.1007/s11709-013-0221-y

摘要: The most critical drawback in currently used steel reinforcement in reinforced concrete (RC) structures is susceptibility to accumulation of plastic deformation under excessive loads. Many concrete structures due to damaged (yielded) steel reinforcement have undergone costly repairs and replacements. This research presents a new type of shape memory alloy (SMA)-based composite reinforcement with ability to withstand high elongation while exhibiting pseudo-elastic behavior. In this study, small diameter SMA wires are embedded in thermoset resin matrix with or without additional glass fibers to develop composite reinforcement. Manufacturing technique of new proposed composite is validated using microscopy images. The proposed SMA-FRP composite square rebars are first fabricated and then embedded in small scale concrete T-beam. 3-point bending test is conducted on manufactured RC beam using a cyclic displacement controlled regime until failure. It is found that the SMA-FRP composite reinforcement is able to enhance the performance of concrete member by providing re-centering and crack closing capability.

关键词: re-centering     shape memory alloys     concrete     composite     fiber reinforced polymer     scanning electron microscopy    

基于谐波的多光子扫描结构光照明超分辨显微成像

汪磊, 郑晓敏, 周洁, 王美婷, 陈嘉杰, 曾佑君, 许改霞, 王颖, 邱海霞, 邵永红, 屈军乐, 高志, 顾瑛

《工程(英文)》 2022年 第16卷 第9期   页码 65-72 doi: 10.1016/j.eng.2021.12.010

摘要: style="text-align: justify;">本文提出了一种利用多光子非线性效应的多光子结构光照明超分辨显微成像(multiphoton-structured illumination microscopy

关键词: 超分辨显微成像     结构光照明超分辨显微成像     多光子结构光照明超分辨显微成像     SIM     二次谐波产生(SHG)-SIM    

Plasma-enabled healing of graphene nano-platelets layer

Xiuqi Fang, Carles Corbella, Denis B. Zolotukhin, Michael Keidar

《化学科学与工程前沿(英文)》 2019年 第13卷 第2期   页码 350-359 doi: 10.1007/s11705-018-1787-7

摘要: Graphene platelet networks (GPNs) were deposited onto silicon substrates by means of anodic arc discharge ignited between two graphite electrodes. Substrate temperature and pressure of helium atmosphere were optimized for the production of the carbon nanomaterials. The samples were modified or destroyed with different methods to mimic typical environments responsible of severe surface degradation. The emulated conditions were performed by four surface treatments, namely thermal oxidation, substrate overheating, exposition to glow discharge, and metal coating due to arc plasma. In the next step, the samples were regenerated on the same substrates with identical deposition technique. Damaging and re-growth of GPN samples were systematically characterized by scanning electron microscopy and Raman spectroscopy. The full regeneration of the structural and morphological properties of the samples has proven that this healing method by arc plasma is adequate for restoring the functionality of 2D nanostructures exposed to harsh environments.

关键词: graphene platelet networks     anodic arc discharge     plasma healing     scanning electron microscopy     Raman spectroscopy    

Fouling mechanisms in the early stage of an enhanced coagulation-ultrafiltration process

Haiqing CHANG,Baicang LIU,Wanshen LUO,Guibai LI

《环境科学与工程前沿(英文)》 2015年 第9卷 第1期   页码 73-83 doi: 10.1007/s11783-014-0692-7

摘要: We investigated the fouling performances of ultrafiltration (UF) membrane for treating in-line coagulated water in an enhanced coagulation-UF hybrid process. Then we analyzed the fouling mechanisms in the early stage of UF using mathematical models and microscopy observation methods. Finally, we discussed the impact of aeration on membrane fouling in this paper. The results showed that a two-stage of trans-membrane pressure (TMP) profile during the operation of enhanced coagulation-UF membrane was observed, and the relationship between permeability and operation time fitted well with a logarithmic curve. Membrane pores blocking and cake filtration were confirmed as main membrane fouling mechanisms using the mathematical models. The two stages of membrane fouling mechanisms were further deduced, namely, the membrane pore narrowing followed by the formation of cake layer. Membrane autopsy analysis using scanning electron microscopy (SEM) images of the membrane surface sampled from different filtration cycles also confirmed the mechanisms of pores blocking and cake filtration. Moreover, according to the variations of the permeability and membrane fouling resistance, aeration was able to mitigate and control the membrane fouling to a certain extent, but the optimization of aeration conditions still needs to be studied.

关键词: coagulation-UF     trans-membrane pressure (TMP)     permeability     membrane fouling resistance     scanning electron microscopy (SEM)    

Experimental investigation of fatigue behavior of spur gear in altered tooth-sum gearing

H. K. SACHIDANANDA, Joseph GONSALVIS, H. R. PRAKASH

《机械工程前沿(英文)》 2012年 第7卷 第3期   页码 268-278 doi: 10.1007/s11465-012-0331-6

摘要:

This paper deals with the contact stress, power loss, and pitting of spur gear tooth in altered tooth-sum gearing for a tooth-sum of 100 teeth when altered by±4% tooth-sum. Analytical and experimental methods were performed to investigate and compare the altered tooth-sum gearing against the standard tooth-sum gearing. The experiments were performed using a power recirculating type test rig. The tooth loads for the experimental investigations were determined considering the surface durability of gears. A clear picture of the surface damage was obtained using a scanning electron microphotograph. The negative alteration in the tooth-sum performed better than the positive alteration in a tooth-sum operating between specified center distances.

关键词: spur gear     power recirculating test rig     altered tooth-sum gearing     scanning electron microscopy (SEM)    

Performance of ionic polymer-metal composite (IPMC) with different surface roughening methods

Ning JIN, Bangfeng WANG, Kan BIAN, Qi CHEN, Ke XIONG,

《机械工程前沿(英文)》 2009年 第4卷 第4期   页码 430-435 doi: 10.1007/s11465-009-0053-6

摘要: Based on permeation and double chemical reduction technology, this paper researches the manufacture of Pt-ionic polymer metal composites (IPMC) and the effect of three types of surface roughening methods on the manufacture and performance of IPMC. The roughening methods include manual polishing, sanding machine polishing, and plasma surface treatment. The appearance and scanning electron microscopy (SEM) features, electro-active deformation and surface resistance characteristics of these IPMC specimens were obtained and compared through specimen tests. The results of the tests indicate that surface roughening technology obviously influences the performance of IPMC. The uniformity and compactness of the metal deposited on the surface and inside the Nafion film are improved by improving surface roughening uniformity. However, the electro-active deformation capability and surface resistance of the specimens decrease at the same time. There is an approximate linear increase relationship between the driving voltage and the bending deformation of the IPMC specimen within a certain voltage range. Under the same specimen dimension, constraints, and driving voltage (3V), the maximum electro-active bending deformation angles of the specimens are about 60°, 45°, and 15° for manual polishing, sanding machine roughening, and plasma treatment, respectively.

关键词: ionic polymer metal composites (IPMC)     surface roughening     scanning electron microscopy (SEM) analyze     actuator     electroless plating    

Applications of atomic force microscopy in immunology

Jiping Li, Yuying Liu, Yidong Yuan, Bo Huang

《医学前沿(英文)》 2021年 第15卷 第1期   页码 43-52 doi: 10.1007/s11684-020-0769-6

摘要: Cellular mechanics, a major regulating factor of cellular architecture and biological functions, responds to intrinsic stresses and extrinsic forces exerted by other cells and the extracellular matrix in the microenvironment. Cellular mechanics also acts as a fundamental mediator in complicated immune responses, such as cell migration, immune cell activation, and pathogen clearance. The principle of atomic force microscopy (AFM) and its three running modes are introduced for the mechanical characterization of living cells. The peak force tapping mode provides the most delicate and desirable virtues to collect high-resolution images of morphology and force curves. For a concrete description of AFM capabilities, three AFM applications are discussed. These applications include the dynamic progress of a neutrophil-extracellular-trap release by neutrophils, the immunological functions of macrophages, and the membrane pore formation mediated by perforin, streptolysin O, gasdermin D, or membrane attack complex.

关键词: cellular mechanics     atomic force microscopy     neutrophil extracellular trap     macrophage phagocytosis     pore formation    

New kind of subarea-parallel scanning mode for laser metal deposition shaping

BIAN Hongyou, LIU Weijun, ZHAO Jibin

《机械工程前沿(英文)》 2007年 第2卷 第4期   页码 417-422 doi: 10.1007/s11465-007-0071-1

摘要: A scanning mode is the key technology in a laser metal deposition shaping (LMDS) fabrication process. On the basis of the analysis of existing scanning modes and their influences on the fabrication efficiency and the quality of parts, some disadvantages of them are pointed out. A new kind of subarea-parallel scanning mode for LMDS based on a subdividing profiled outline into monotonous polygon subareas is presented. First, based on the principle of point visibility, inner loops are eliminated, and simple polygons are subdivided into monotonous polygons with the minimal zones. Second, the parallel scanning paths of all monotonous polygon subareas are finished, which diminishes the length of the scanning line. The practical application shows that the scanning mode can enhance the fabrication efficiency and quality.

关键词: scanning     parallel scanning     practical application     fabrication efficiency     LMDS    

Changes of ecological conditions induced by rock tunneling in Laoshan Mountain area

LI Xiaozhao, ZHAO Xiaobao, WANG Zhongsheng

《结构与土木工程前沿(英文)》 2008年 第2卷 第4期   页码 366-370 doi: 10.1007/s11709-008-0056-0

摘要: Through field investigation, this paper examined the changes of ecological conditions induced by tunnel construction in Laoshan Mountain area, Nanjing, Jiangsu Province, P. R. China. The effects of habitat fragmentation and edge effect are examined and discussed. It is found that the environmental factors and vegetation situation have been influenced by the tunneling activity, and the disturbed area is approaching the sampling patch centre. The changed ecological conditions are beneficial for the settlement and growth of some herb and shrub species, and are unfavorable for the existence and growth of saplings, especially for the predominant species (e.g., robur) in this area. If the time of habitat fragmentation is long enough and there is no supplement from external areas, some vegetation species in the engineering influencing area will deteriorate, or even diminish in the future. The results can be used as a reference for the long-term ecological study in this area.

关键词: supplement     fragmentation     reference     tunneling activity     vegetation situation    

宫内节育器表面的细菌生物膜研究

张向卉,曲雯雯,黄薇,方 婕,吴凡子,周辛璇

《中国工程科学》 2015年 第17卷 第6期   页码 21-27

摘要:

目的:宫内节育器(IUD)是目前常用的长效避孕措施之一,然而众多研究认为IUD的应用增加了盆腔炎性疾病(PID)的发生率。近年研究发现细菌生物膜(BF)与感染性疾病的发生息息相关,本研究拟探究无盆腔炎疾病妇女的不同类型宫内节育器表面是否存在BF,了解IUD是否为BF形成提供平台,是否增加盆腔炎性疾病的易感性。方法:不同类型IUD标本,根据表面清洁程度分别进行单独电子扫描电镜(SEM)观察,单独需氧、厌氧细菌培养,以及SEM观察+培养了解IUD表面是否存在BF。结果:共纳入IUD标本86例,85例非PID女性的IUD,同期1例盆腔感染性疾病患者的IUD。25例进行单独SEM观察,阳性1例,其余标本未见典型BF结构。单独细菌培养47例,需氧细菌培养阳性1例,见大面积菌苔覆盖,考虑污染可能性大,其余标本未见细菌生长。SEM联合培养14例,细菌培养阳性,电镜无阳性发现。其余培养及SEM观察阴性。结论:不论IUD的类型如何,非PID女性体内的IUD表面无BF存在,不同与其他体内医疗装置,BF的形成不能成为限制IUD应用的理由。

关键词: 宫内节育器;盆腔炎性疾病;细菌生物膜;SEM    

Analysis and comparison of laser cutting performance of solar float glass with different scanning modes

Wenyuan LI, Yu HUANG, Youmin RONG, Long CHEN, Guojun ZHANG, Zhangrui GAO

《机械工程前沿(英文)》 2021年 第16卷 第1期   页码 97-110 doi: 10.1007/s11465-020-0600-8

摘要: Cutting quality and efficiency have always been important indicators of glass laser cutting. Laser scanning modes have two kinds, namely, the spiral and concentric circle scanning modes. These modes can achieve high-performance hole cutting of thick solar float glass using a 532-nm nanosecond laser. The mechanism of the glass laser cutting under these two different scanning modes has been described. Several experiments are conducted to explore the effect of machining parameters on cutting efficiency and quality under these two scanning modes. Results indicate that compared with the spiral scanning mode, the minimum area of edge chipping (218340 µm ) and the minimum Ra (3.01 µm) in the concentric circle scanning mode are reduced by 9.4% and 16.4% respectively. Moreover, the best cutting efficiency scanning mode is 14.2% faster than that in the spiral scanning mode. The best parameter combination for the concentric circle scanning mode is as follows: Scanning speed: 2200 mm/s, number of inner circles: 6, and circle spacing: 0.05 mm. This parameter combination reduces the chipping area and sidewall surface roughness by 8.8% and 9.6% respectively at the same cutting efficiency compared with the best spiral processing parameters. The range of glass processing that can be achieved in the concentric circle scanning mode is wider than that in the spiral counterpart. The analyses of surface topography, white spots, microstructures, and sidewall surface element composition are also performed. The study concluded that the concentric circle scanning mode shows evident advantages in the performance of solar float glass hole cutting.

关键词: laser cutting     solar float glass     scanning mode     surface quality     cutting efficiency    

Review of MEMS differential scanning calorimetry for biomolecular study

Shifeng YU, Shuyu WANG, Ming LU, Lei ZUO

《机械工程前沿(英文)》 2017年 第12卷 第4期   页码 526-538 doi: 10.1007/s11465-017-0451-0

摘要:

Differential scanning calorimetry (DSC) is one of the few techniques that allow direct determination of enthalpy values for binding reactions and conformational transitions in biomolecules. It provides the thermodynamics information of the biomolecules which consists of Gibbs free energy, enthalpy and entropy in a straightforward manner that enables deep understanding of the structure function relationship in biomolecules such as the folding/unfolding of protein and DNA, and ligand bindings. This review provides an up to date overview of the applications of DSC in biomolecular study such as the bovine serum albumin denaturation study, the relationship between the melting point of lysozyme and the scanning rate. We also introduce the recent advances of the development of micro-electro-mechanic-system (MEMS) based DSCs.

关键词: differential scanning calorimetry     biomolecule     MEMS     thermodynamic    

Comparison of shallow tunneling method with pile and rib method for construction of subway station in

Sina AMIRI; Ali Naghi DEHGHAN

《结构与土木工程前沿(英文)》 2022年 第16卷 第6期   页码 704-717 doi: 10.1007/s11709-021-0746-4

摘要: In the present study, a comparison between the new shallow tunneling method (STM) and the traditional pile and rib method (PRM) was conducted to excavate and construct subway stations in the geological conditions of Tehran. First, by selecting Station Z6 located in the Tehran Subway Line 6 as a case study, the construction process was analyzed by PRM. The maximum ground settlement of 29.84 mm obtained from this method was related to the station axis, and it was within the allowable settlement limit of 30 mm. The acceptable agreement between the results of numerical modeling and instrumentation data indicated the confirmation and accuracy of the excavation and construction process of Station Z6 by PRM. In the next stage, based on the numerical model validated by instrumentation data, the value of the ground surface settlement was investigated during the station excavation and construction by STM. The results obtained from STM showed a significant reduction in the ground surface settlement compared to PRM. The maximum settlement obtained from STM was 6.09 mm as related to the front of the excavation face. Also, the sensitivity analysis results denoted that in addition to controlling the surface settlement by STM, it is possible to optimize some critical geometric parameters of the support system during the station excavation and construction.

关键词: shallow tunneling method     pile and rib method     ground surface settlement     subway station construction     numerical modeling    

标题 作者 时间 类型 操作

Two-dimensional self-assembly of melem and melemium cations at pH-controlled aqueous solution–Au(111) interfaces under electrochemical control

Shinobu Uemura,Kenki Sakata,Masashi Aono,Yusuke Nakamura,Masashi Kunitake

期刊论文

Review: Tip-based vibrational spectroscopy for nanoscale analysis of emerging energy materials

Amun JARZEMBSKI, Cedric SHASKEY, Keunhan PARK

期刊论文

Experimental flexural behavior of SMA-FRP reinforced concrete beam

Adeel ZAFAR, Bassem ANDRAWES

期刊论文

基于谐波的多光子扫描结构光照明超分辨显微成像

汪磊, 郑晓敏, 周洁, 王美婷, 陈嘉杰, 曾佑君, 许改霞, 王颖, 邱海霞, 邵永红, 屈军乐, 高志, 顾瑛

期刊论文

Plasma-enabled healing of graphene nano-platelets layer

Xiuqi Fang, Carles Corbella, Denis B. Zolotukhin, Michael Keidar

期刊论文

Fouling mechanisms in the early stage of an enhanced coagulation-ultrafiltration process

Haiqing CHANG,Baicang LIU,Wanshen LUO,Guibai LI

期刊论文

Experimental investigation of fatigue behavior of spur gear in altered tooth-sum gearing

H. K. SACHIDANANDA, Joseph GONSALVIS, H. R. PRAKASH

期刊论文

Performance of ionic polymer-metal composite (IPMC) with different surface roughening methods

Ning JIN, Bangfeng WANG, Kan BIAN, Qi CHEN, Ke XIONG,

期刊论文

Applications of atomic force microscopy in immunology

Jiping Li, Yuying Liu, Yidong Yuan, Bo Huang

期刊论文

New kind of subarea-parallel scanning mode for laser metal deposition shaping

BIAN Hongyou, LIU Weijun, ZHAO Jibin

期刊论文

Changes of ecological conditions induced by rock tunneling in Laoshan Mountain area

LI Xiaozhao, ZHAO Xiaobao, WANG Zhongsheng

期刊论文

宫内节育器表面的细菌生物膜研究

张向卉,曲雯雯,黄薇,方 婕,吴凡子,周辛璇

期刊论文

Analysis and comparison of laser cutting performance of solar float glass with different scanning modes

Wenyuan LI, Yu HUANG, Youmin RONG, Long CHEN, Guojun ZHANG, Zhangrui GAO

期刊论文

Review of MEMS differential scanning calorimetry for biomolecular study

Shifeng YU, Shuyu WANG, Ming LU, Lei ZUO

期刊论文

Comparison of shallow tunneling method with pile and rib method for construction of subway station in

Sina AMIRI; Ali Naghi DEHGHAN

期刊论文