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Scalable fabrication of microneedle arrays via spatially controlled UV exposure

Microsystems & Nanoengineering 2016年第1期2卷 73-81页

作者： Hidetoshi Takahashi Yun Jung Heo Nobuchika Arakawa Tesuo Kan Kiyoshi Matsumoto Ryuji Kawano Isao Shimoyama Department of Mechano-Informatics Graduate School of Information Science and Technologythe University of Tokyo7-3-1 HongoBunkyo-kuTokyo 113-8656Japan Department of Mechanical Systems Engineering Graduate School of EngineeringTokyo University of Agriculture and Technology2-24-16 Naka-choKoganei-shiTokyo 184-8588Japan Department of Mechanical Engineering and Intelligent Systems Graduate School of Informatics and Engineeringthe University of Electro-Communications1-5-1 ChofugaokaChofu-shiTokyo 182-8585Japan irt research initiative the University of Tokyo7-3-1 HongoBunkyo-kuTokyo 113-8656Japan Department of Biotechnology and Life Science Graduate School of EngineeringTokyo University of Agriculture and Technology2-24-16 Naka-choKoganei-shiTokyo 184-8588Japan

This paper describes a theoretical estimation of the geometry of negative epoxy-resist microneedles prepared via inclined/rotated ultraviolet(UV)lithography based on spatially controlled UV exposure *** comparison with other methods based on UV lithography,the present method can create microneedle structures with high *** negative photoresist is exposed to inclined/rotated UV through circular mask patterns,a three-dimensional,needle-shaped distribution of the exposure dose forms in the irradiated *** the inclination angles and the exposure dose modifies the photo-polymerized portion of the photoresist,thus allowing the variation of the heights and contours of microneedles formed by using the same mask *** an experimental study,the dimensions of the fabricated needles agreed well with the theoretical predictions for varying inclination angles and exposure *** results demonstrate that our theoretical approach can provide a simple route for fabricating microneedles with on-demand *** fabricated microneedles can be used as solid microneedles or as a mold master for dissolving microneedles,thus simplifying the microneedle fabrication *** envision that this method can improve fabrication accuracy and reduce fabrication cost and time,thereby facilitating the practical applications of microneedle-based drug delivery technology.

关键词： inclined/rotated lithography microneedle array UV exposure ratio

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Experimental Study on Wear and Spalling Behaviors of Railway Wheel

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Chinese Journal of Mechanical Engineering 2013年第6期26卷 1243-1249页

作者： WANG Wenjian GUO Jun LIU Qiyue Tribology research Institute Southwest Jiaotong University

The current researches of the wear and spalling behaviors of wheel/rail materials focus on the field investigation rather than the mechanism. However, it is necessary and significant for clarifying the mechanism and relationship between the wear and spalling damage of railway wheel to test and reproduce the wheel damages in laboratory. The objective of this paper is to investigate the wear and spalling damage behaviors of railway wheel using a JD-1 wheel/rail simulation facility, which consists of a small wheel serving as rolling stock wheel, and a larger wheel serving as rail. The damage process of wheel roller is explored in terms of the creep ratio, axle load, and carbon content by means of various microscopic examinations. The experimental results show that the wear volume growth of wheel roller is proved to be proportional to the increase of the creep ratio and normal load between simulating wheel and rail. The increase of carbon content of wheel material causes a linear reduction in the wear volume. The microscopic examinations indicate that the rolling wear mechanism transfers from abrasive wear to adhesive and fatigue wear with an increase of tangential friction force, which results in the initiation of fatigue crack, and then aggravates spalling damage on the wheel roller surface. The surface hardness of material depends strongly upon its carbon content. The decrease of the carbon content of wheel material may alleviate spalling damage, but can cause a significant growth in the wear volume of wheel roller. Therefore, there is a competitive relationship between the wear and spalling damage of wheel material. This research proposes an important measure for alleviating or preventing the wear and spalling damage of railway wheel material.

关键词： wear spalling content carbon railway wheel wear mechanism

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A Hazard Analysis-based Approach to Improve the Landing Safety of a BWB Remotely Piloted Vehicle

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Chinese Journal of Aeronautics 2012年第6期25卷 846-853页

作者： LU Yi ZHANG Shuguang LI Xueqing Airworthiness Technologies research Center Beihang University Beijing 100191 China

The BUAA-BWB remotely piloted vehicle （RPV） designed by our research team encountered an unexpected landing safety problem in flight tests. It has obviously affected further research project for blended-wing-body （BWB） aircraft configuration characteristics. Searching for a safety improvement is an urgent requirement in the development work of the RPV. In view of the vehicle characteristics, a new systemic method called system-theoretic process analysis （STPA） has been tentatively applied to the hazardous factor analysis of the RPV flight test. An uncontrolled system behavior ＂path sagging phenomenon＂ is identified by implementing a three degrees of freedom simulation based on wind tunnel test data and establishing landing safety system dynamics archetype. To obtain higher safety design effectiveness and considering safety design precedence, a longitudinal ＂belly-flap＂ control surface is innovatively introduced and designed to eliminate hazards in landing. Finally, flight tests show that the unsafe factor has been correctly identified and the landing safety has been efficiently improved.

关键词： BWB RPV landing safety STPA system dynamics safety design precedence sagging phenomenon belly-flap

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Sensitivity Analysis for Safety Design Verification of General Aviation Reciprocating Aircraft Engine

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Chinese Journal of Aeronautics 2012年第5期25卷 675-680页

作者： CAO Jiaokun DING Shuiting Airworthiness Technologies research Center Beihang UniversityBeijing 100191China

This paper presents an application of global sensitivity analysis for system safety analysis of reciprocating aircraft engine. Compared with local sensitivity analysis results, global sensitivity analysis could provide more information on parameter inter- actions, which are significant in complex system safety analysis. First, a deterministic aviation reciprocating engine thermody- namics model is developed and parameters of interest are defined as random variables. Then, samples are generated by Monte Carlo method for the parameters used in engine model on the basis of definition of factor distribution. Eventually, results from engine model are generated and importance indices are calculated. Based on the analysis results, design is improved to satisfy the airworthiness requirements. The results reveal that by using global sensitivity analysis, the parameters could be ranked with respect to their importance, including first order indices and total sensitivity indices. By reducing the uncertainty of parameters and adjusting the range of inputs, safety criteria would be satisfied.

关键词： sensitivity analysis safety analysis airworthiness reciprocating aircraft engine design verification

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Tidal effects on diel variations of picoplankton and viruses in the Changjiang estuary

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Chinese Journal of Oceanology and Limnology 2010年第3期28卷 435-442页

作者：李云李道季方涛张利华王延明 East China Sea Fisheries research Institute Chinese Academy of Fishery Sciences State Key Laboratory of Estuarine and Coastal research East China Normal University

Spatial distributions and seasonal variations of picoplankton (i.e. Synechococcus spp., Prochlorococcus spp., picoeukaryotes and heterotrophic bacteria) and viruses in the Changjiang estuary have been reported in the past. However, short-term variations (e.g. at a tidal timescale) of these organisms and their regulating factors remain unclear. We determined the time-series of fluctuations of picoplankton and viruses with tide simultaneously in flow cytometry in the Changjiang estuary during a cruise in June 2006, in which a tidal model based rectangle equation was applied. The results indicate that high cell abundances of picoplankton and viruses occurred during flood tide and low cell abundances during ebb tide. The period of the surface cell abundance variations was about 13 h, suggesting the surface cell abundances in the Changjiang estuary were largely regulated by tide. However, cell abundances in middle and bottom waters varied in different periods due to influences of tidal induced physical forces such as resuspension and stratification. Therefore, tidal action is an important factor for the diel variations of picoplankton and viruses in the Changjiang estuary.

关键词： picoplankton viruses tidal effect Changjiang estuary

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Friction and Wear Properties of High-velocity Oxygen Fuel Sprayed WC-17Co Coating under Rotational Fretting Conditions

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Chinese Journal of Mechanical Engineering 2016年第3期29卷 515-521页

作者： LUO Jun CAI Zhenbing MO Jiliang PENG Jinfang ZHU Minhao Tribology research Institute Southwest Jiaotong UniversityChengdu 610031China Engineering research Center for Materials Protection of Wear and Corrosion of Guizhou Provincial Universities Guiyang University Guiyang 550005China

Rotational fretting which exist in many engineering applications has incurred enormous economic loss. Thus, accessible methods are urgently needed to alleviate or eliminate damage by rotational fretting. Surface engineering is an effective approach that is successfully adopted to enhance the ability of components to resist the fretting damage. In this paper, using a high-velocity oxygen fuel sprayed（HVOF） technique WC-17 Co coating is deposited on an LZ50 steel surface to study its properties through Vickers hardness testing, scanning electric microscope（SEM）, energy dispersive X-ray spectroscopy（EDX）, and X-ray diffractrometry（XRD）. Rotational fretting wear tests are conducted under normal load varied from 10 N to 50 N, and angular displacement amplitudes vary from 0.125° to 1°. Wear scars are examined using SEM, EDX, optical microscopy（OM）, and surface topography. The experimental results reveal that the WC-17 Co coating adjusted the boundary between the partial slip regime（PSR） and the slip regime（SR） to the direction of smaller amplitude displacement. As a result, the coefficients of friction are consistently lower than the substrate＇s coefficients of friction both in the PSR and SR. The damage to the coating in the PSR is very slight. In the SR, the coating exhibits higher debris removal efficiency and load-carrying capacity. The bulge is not found for the coating due to the coating＇s higher hardness to restrain plastic flow. This research could provide experimental bases for promoting industrial application of WC-17 Co coating in prevention of rotational fretting wear.

关键词： fretting wear rotational fretting WC-17Co coating LZ50 steel HVOF

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Cascading electron transfer and photophysics in a donor-π-acceptor graphene nanoconjugate

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Nano research 2023年第4期16卷 5909-5918页

作者： Lulu Fu Hui Li Yan Fang Zihao Guan Zhiyuan Wei Naying Shan Fang Liu Yang Zhao Mingfei Zhang Zhipeng Huang Mark GHumphrey Chi Zhang China-Australia Joint research Center for Functional Molecular Materials School of Chemical Science and EngineeringTongji UniversityShanghai 200092China research School of Chemistry Australian National UniversityCanberraACT 2601Australia

Electron-donating porphyrins(Por),electron-accepting phthalocyanines(Pcs),and reduced graphene oxide(RGO)were integrated into a multicomponent nanoconjugate(Por-RGO-Pc).The donor-π-acceptor nanoconjugate Por-RGO-Pc was characterized using Fourier transform infrared spectroscopy(FTIR),transmission electron microscopy(TEM),scanning electron microscopy(SEM),atomic force microscopy(AFM),and ultraviolet-visible(UV-Vis)*** cascading electron/charge transfer from Por to RGO and from RGO to Pc was established from fluorescence,electrochemical,and femtosecond transient absorption(fs-TA)spectroscopy *** increased distance between the electron donors and acceptors of the Por-RGO-Pc nanoconjugate compared to the parent materials and the intermediate RGO-Pc results in longlived charge separation,and an enhancement in nonlinear optical(NLO)absorption(a large NLO coefficient of about 827.44 cm/GW)towards nanosecond laser irradiation at 532 nm.

关键词： graphene nanoconjugate donor-π-acceptor(D-π-A) cascading charge separation nonlinear optics

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A 1,3-dipolar cycloaddition protocol to porphyrin- functionalized reduced graphene oxide with a push-pull motif

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Nano research 2015年第3期8卷 870-886页

作者： Aijian Wang Wang Yu Zhengguo Xiao Yinglin Song Lingliang Long Marie P. Cifuentes Mark G. Humphrey Chi Zhang China-Australia Joint research Center for Functional Molecular Materials School of Chemical and Material Engineering Jiangnan University Wuxi 214122 China China-Australia Joint research Center for Functional Molecular Materials Scientific Research Academy Jiangsu University Zhenjiang 212013 China School of Physical Science and Technology Soochow University Suzhou 215006 China research School of Chemistry Australian National University Canberra ACT0200 Australia

Reduced graphene oxide （RGO） has been covalently functionalized with porphyrin moieties by two methods： A straightforward Prato reaction （i.e. a 1,3-dipolar cycloaddition） with sarcosine and a formyl-containing porphyrin, and a stepwise method that involves a 1,3-dipolar cycloaddition to the RGO surface using 4-hydroxybenzaldehyde, followed by nucleophilic substitution with an appropriate porphyrin. The chemical bonding of porphyrins to the RGO surface has been confirmed by ultraviolet/visible absorption, fluorescence, Fourier-transform infrared, and Raman spectroscopies, X-ray powder diffraction and X-ray photoelectron specfroscop）~ transmission electron and atomic force microscopy, and thermogravimetric analysis; this chemical attachment assures efficient electron/energy transfer between RGO and the porphyrin, and affords improved optical nonlinearities compared to those of the RGO precursor and the pristine porphyrin.

关键词： porphyrin cycloaddition reduced graphene oxide nonlinear optics

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Strong near-infrared and ultrafast femtosecond nonlinearities of a covalently-linked triply-fused porphyrin dimer-SWCNT nanohybrid

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Nano research 2022年第2期15卷 1355-1365页

作者： Lulu Fu Jun Ye Hui Li Zhipeng Huang Mark GHumphrey Chi Zhang China-Australia Joint research Center for Functional Molecular Materials School of Chemical and Material EngineeringJiangnan UniversityWuxi 214122China China-Australia Joint research Center for Functional Molecular Materials School of Chemical Science and Engineerinz Ton^ii UniversityShanghai 200092China research School of Chemistry Australian National UniversityCanberraACT 2601Australia

Functional materials displaying large ultrafast third-order optical nonlinearities across a wide spectral region and broad temporal domain are required for all-optical signal *** desirable is nonlinear optical(NLO)activity at near-infrared(NIR)wavelengths with femtosecond *** the first triply-fused porphyrin dimer(TFP)-functionalized single-walled carbon nanotube(SWCNT)nanohybrid was successfully constructed by covalently grafting TFPs onto *** results of Z-scan techniques demonstrate that the newly obtained TFP-SWCNT nanohybrid was found with a strong NLO performance under both nanosecond and femtosecond *** the nanosecond regime,an enhancement in optical limiting(OL)of the TFP-SWCNT nanohybrid is seen at 532 nm when compared with the performance of porphyrin monomer-functionalized SWCNT nanohybrid *** femtosecond irradiation,the TFP-SWCNT nanohybrid exhibits a particularly strong OL effect with a giant two-photon absorption(TPA)cross section value(ca.15,500 GM)at 800 nm pulses that mainly stems from intense TPA of TFP,in sharp contrast to the Por-SWCNT nanohybrid which exhibits only saturable absorption under identical *** results demonstrate that the newly-developed TFP-SWCNT nanohybrid is a very promising OL candidate for practical applications across wide spectral and temporal domains,and that covalently functionalizing carbon-based materials with triply-fused chromophores may be a useful approach to engineering adaptable photonic devices with broad-ranging NLO activity.

关键词： triply-fused porphyrin dimer carbon nanotube near-infrared femtosecond nonlinear optical materials

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Synopsis of Leymus Hochst.(Triticeae:Poaceae)

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Journal of Systematics and Evolution 2009年第1期47卷 67-86页

作者： Bernard R.BAUM Eastern Cereals and Oilseeds research Centre Agriculture and Agri-Food CanadaCentral Experimental Farm

Leymus is a genus in the Triticeae tribe, Poaceae. The taxa of this genus are allopolyploid species which possess the Ns and Xm genomes. According to cytological, cytogenetic and molecular genetic analyses, some species of Hystrix and Elymus ought to be transferred to this genus. A world revision of the genus Leymus is needed. In this paper we summarize experimental results, provide a key to sections, species and varieties, and list all the taxa we recognize in Leymus with their synonyms. This synopsis is a new taxonomic system to be used for the revision of Leymus.

关键词： genome Leymus new taxonomic system section species varieties

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