Modulation and effects of surface groups on
亮黄色荧光碳点的合成及可见光催化降解酸性品红
亮黄色荧光碳点的合成及可见光催化降解酸性品红李锋;李洪仁;方坤;戚娟娟【摘要】以抗坏血酸和甘氨酸为反应物,在磷酸存在下应用溶剂热法一步合成出365 nm紫外光激发下呈亮黄色荧光的碳点.用X射线衍射(XRD)、透射电镜(TEM)、荧光光谱(XRF)和红外光谱(FTIR)对碳点的物相、形貌和粒径、光致发光性能及表面基团等进行了表征;研究了碳点/H2O2催化体系在对酸性品红的降解性能,用荧光光谱法推测了可能的反应机理.结果表明,合成的碳点粒径约5 nm,分散性好,表面富含—OH、C=O等基团,具有激发波长依赖的发光特性.30 mg·L-1的酸性品红溶液在可见光照射下,180 min内可降解92％,降解过程中有羟基自由基生成.【期刊名称】《沈阳大学学报》【年(卷),期】2015(027)003【总页数】4页(P189-192)【关键词】碳点;发光;光催化;酸性品红【作者】李锋;李洪仁;方坤;戚娟娟【作者单位】沈阳大学师范学院,辽宁沈阳 110044;沈阳大学师范学院,辽宁沈阳110044;沈阳大学师范学院,辽宁沈阳 110044;沈阳大学师范学院,辽宁沈阳110044【正文语种】中文【中图分类】O613.71;O644.14碳点(Carbon Dots, CDs)是近几年来出现的一种直径小于10nm的新型碳纳米颗粒.碳点具有激发波长和发射波长可调谐、荧光稳定耐光漂白且无光闪烁现象等优异的荧光性能[1-3].碳点还具有优异的水溶性和化学稳定性,易于功能化,低毒性和良好的生物相容性等优点[4].碳点可以通过细胞内吞进入细胞内部而不影响细胞核,还可以与DNA生物大分子相互作用,从而来进行细胞成像和DNA的识别与检测[5-6].因此,碳点可以作为半导体量子点(如CdS、CdSe、CdTe等)和有机染料的替代物而被应用于生物标记和生物成像等领域.而且,光激发的碳点展现了优良的电子供体和电子受体性质为设计高效稳定的光催化剂提供了新的选择[7].最近, 能源和环境问题日益引起研究者的广泛关注. 工业污染物的排放严重威胁着人类的进一步发展, 特别是一些染料废水具有排放量大、组分复杂、色度大、可生化性差等特点, 是最难处理的工业废水之一[8]. 光催化氧化技术能够将绝大部分的有机污染彻底降解为二氧化碳和水. 光催化技术的关键是光催化剂, 由于TiO2化学性质稳定、氧化能力强和低廉的价格, 使之成为过去几十年来最重要的光催化材料[9]. 然而,TiO2带隙较宽(约为3.2eV), 只能吸收太阳光中的紫外光, 太阳能利用率极低; 另一方面光生电子和空穴很容易重新复合, 影响了光催化效率[10]. 具有电子接受和传导能力的荧光碳点提供了一种简便的光生载流子的传输途径, 因此, 一些关于碳点光催化剂用于提高光催化性能的工作被报道[11-13].本文采用溶剂热法以抗坏血酸为碳源,甘氨酸为钝化剂,在磷酸存在下一步合成出365nm紫外光激发下呈现亮黄色荧光的碳点.通常,合成的碳点在365nm紫外光激发下大多是具有蓝色荧光的光致发光特性.该方法制备碳点工艺简单,原料易得,条件可控,制备出的碳点发光强度高,稳定性好.酸性品红(Acid Fuchsin, AF)是一种常用的水溶性染料,分子结构中含有共轭的苯环结构,常用的生物法和化学法都难以降解.以酸性品红为模拟污染物,研究了合成的荧光碳点在可见光照射下对酸性品红的催化降解性能.1.1 试剂和仪器抗坏血酸、甘氨酸、磷酸、乙二醇、酸性品红、双氧水、香豆素,均为分析纯试剂,购自国药集团化学试剂有限公司.X’ Pert Pro型多晶X射线衍射仪(荷兰PANalytical公司),H-7650透射电子显微镜(日本HITACHI公司,工作电压100kV),Spectrum One FTIR红外光谱仪(美国Perkin Elmer公司),LS-55 荧光分光光度计(美国Perkin Elmer公司),UV-2100紫外可见分光光度计(北京瑞利公司),HN101-0A数显电热恒温干燥箱(南通沪南科学仪器有限公司),50mL高压水热反应釜(巩义市予华仪器有限公司),300W卤钨灯.1.2 荧光碳点的制备称取0.50g抗坏血酸和0.15g甘氨酸于烧杯中,并加入5mLH3PO4和25mL乙二醇,搅拌均匀,然后转入50mL水热反应釜中,在90℃下,溶剂热反应3h,取出冷却至室温得到棕黄色碳点溶液.1.3 荧光碳点光催化性能测试以酸性品红作为模拟污染物,在可见光照射下考察碳点的催化活性.取100mL(质量浓度为30mg·L-1)酸性品红溶液于250mL烧杯中,加入1.0mL合成的碳点溶液和500μLH2O2(质量分数为30%).混合溶液磁力搅拌下用300W卤钨灯进行光照射,每隔一定时间取样,通过紫外-可见分光光度计在波长546nm处测定酸性品红溶液的吸光度,然后通过以下的方程计算酸性品红的脱色率:式中:A0为酸性品红溶液起始吸光度,A为不同t时刻酸性品红溶液吸光度值.1.4 羟基自由基的测定羟基自由基的测定按文献[14]方法,以香豆素为羟基自由基捕获剂,无荧光的香豆素分子被可见光照射下的碳点与H2O2催化体系产生的羟基自由基氧化成最大发射波长在456nm附近的强荧光的7-羟基香豆素,通过荧光光谱法进行检测.2.1 XRD表征图1为制备的碳点的X射线衍射图,在2θ=22°左右出现了一个明显且很宽的衍射峰,这个峰是碳的无定形态的特征峰[15].这说明由该合成方法制得的碳点属于无定形碳.2.2 TEM表征对合成的碳点进行了TEM表征,如图2所示,合成的碳点粒径相对比较均匀,尺寸大小在5nm左右,具有很好的分散性.这说明,以抗坏血酸和甘氨酸为反应物在乙二醇介质中溶剂热反应可以得到具有良好分散性的荧光碳点.2.3 碳点的发光性能合成的碳点有良好的水溶性,其水溶液在365nm紫外光照射下发射出亮黄色荧光,显示出优异的光致发光性能.为了进一步表征制备的碳点的发光性质,对其进行了荧光光谱检测.如图3所示,碳点水溶液具有荧光激发波长依赖性,随着激发波长的增加,荧光发射峰强度先增强后下降,且随着激发波长的增加荧光发射峰位逐渐红移,呈现出发射波长随激发波长变化而变化的光谱特性.合成的碳点的这些特性与文献报道一致[16],这可能是由于碳点表面不同的发光位点,以及碳点制备过程中形成的不均匀粒径所导致的量子尺寸效应等原因而造成的.2.4 红外表征碳点红外光谱如图4所示,3420cm-1处出现了羟基(—OH)伸缩振动吸收峰,羰基(C=O)伸缩振动吸收峰(1640cm-1).这说明,碳点表面富含—OH、C=O等亲水性基团,使碳点在溶液中具有良好的亲水性和稳定性,这一性质使碳点能很好的应用于水相反应.1150cm-1归属于—P=O(OH)2基团中P=O的伸缩振动.红外光谱表明磷酸已参与反应且使碳点表面功能化.2.5 碳点的光催化活性以酸性品红为模拟污染物,考察了可见光照射下碳点/H2O2协同体系的催化降解活性.图5是碳点/H2O2在可见光照射下酸性品红溶液的吸收光谱变化图.酸性品红溶液的最大吸收峰在546nm处,这个吸收峰是由酸性品红分子中3个共轭双键发色基团引起的.在可见光照射下,的吸收峰强度快速下降,这表明酸性品红分子被催化分解.光照180min后,质量浓度为30mg·L-1酸性品红溶液的最大吸收峰几乎完全消失,脱色率达到92%,这说明分子中发色的双键被断裂[17].这一结果表明,可见光照射下,碳点/H2O2催化体系对酸性品红的降解实质是发色的双键被断裂.一般认为羟基自由基是光催化氧化过程中最主要的活性物种.采用荧光光谱测试技术检测碳点/H2O2催化体系,在可见光照射下能否产生羟基自由基(•OH),基于的原理是本身无荧光响应的香豆素分子和•OH反应后产生具有荧光特性的7-羟基香豆素.由图6可见, 香豆素溶液无荧光响应,但与碳点/H2O2混合经可见光照射30min 后,在约456nm处有明显的荧光响应,说明该过程中有•OH生成.这一结果表明,•OH参与了酸性品红的降解过程.以抗坏血酸和甘氨酸为反应物,在磷酸存在下经一步溶剂热法成功制备了365nm 紫外光激发下呈现亮黄色荧光的碳点.该方法制备碳点原料廉价,步骤简单,条件温和可控.所制备的碳点由无定型态碳组成,粒径约5nm,表面有羟基、羰基等亲水基团,因此具有良好的水溶性.光降解实验结果表明,在可见光照射下,1.0mL的碳点溶液和500 μLH2O2协同催化体系可在180min内可将质量浓度为30mg·L-1的酸性品红降解92%.荧光实验证明,羟基自由基参与了酸性品红的降解过程.【相关文献】[1] Zhang Y Q, Ma D K, Zhuang Y, et al. One-Pot Synthesis of N-Doped Carbon Dots with Tunable Luminescence Properties[J]. Journal of Materials Chemis try, 2012,22(33):16714-16718.[2] Chandra S, Pathan S H, Mitra S, et al. Tuning of Photoluminescence on Different Surface Functionalized Carbon Quantum Dots[J]. RSC Advances, 2012,2(9):3602-3606.[3] Liu C J, Zhang P, Feng T, et al. One-Step Synthesis of Surface Passivated Carbon Nanodots by Microwave Assisted Pyrolysis fo r Enhanced Multicolor Photoluminescence and Bioimaging[J]. Journal of Materials Chemis try, 2011,21(35): 13163-13167.[4] Zhu C Z, Zhai J F, Dong S J. Bifunctional Fluorescent Carbon Nanodots: Green Synthesis via Soy Milk and Application as Metal-free Electrocatalysts for Oxygen Reduction[J]. Chemical Communications, 2012,48(75):936 7-9369.[5] Luo P G, Sahu S, Yang S T, et al. Carbon “Quantum” Dots for Optical Bioimaging[J]. J ournal of Materials Chemistry B, 2013,1(16):2116-2127.[6] Bai W J, Zheng H Z, Long Y J, et al. A Carbon Dots-Based Fluorescence Turn-on Method for DNA Determination[J]. Analytical Sciences, 2011,27(3):243-246.[7] Liu R H, Huang H, Li H T, et al. Metal Nanoparticle/Carbon Quantum Dot Composite asa Photocatalyst for High-Efficiency Cyclohexane Oxidation[J]. ACS Catalysis, 2014,4(1):328-336.[8] 卢婧,余志晟,张洪勋. 染料微生物降解的方法研究进展[J]. 工业水处理, 2014,34(1):1-4.(Lu Jing,Yu Zhisheng,Zhang Hongxun. Research Progress in the Microbial Degradation of Dye[J]. Industrial Water Treatment, 2014, 34(1):1-4.)[9] Kumar S G, Devi L G. Review on Modified TiO2 Photocatalysis under UV/Visible Light: S elected Results and Related Mechanisms on Interfacial Charge Carrier Transfer Dynamics[J ]. The Journal of Physical Chemistry A, 2011,115(46):13211-13241.[10] Zhang X, Wang F, Huang H, et al. Carbon Quantum Dot Sensitized TiO2 Nanotube Arr ays for Photoelectrochemical Hydrogen Generation under Visible Light[J]. Nanoscale, 201 3,5(6):2274-2278。
1994-JAE。Effect of surface modification using various acids on
Received 23 August 1994; revised 4 November 1994
1. Introduction
Recently, rechargeable lithium batteries with lithium metal anodes have been proposed as power supplies because of their theoretical high energy and power densities. However, they have not been widely used because of their low rechargeability [1-3]. The low rechargeability is caused by the chemical reaction of lithium with nonaqueous electrolytes and the dendrite formation of lithium during the charging process [4, 5]. The lithium dendrites sometimes lose electrical contact with current collectors during charge/ discharge cycles. This makes part of the lithium inaccessible to discharge. Such lithium has been called 'dead lithium'. The morphology of lithium is crucial to high rechargeability. Some studies have proposed that the morphology of electrodeposited lithium is strongly related to the surface states of lithium. The presence of some organic and inorganic compounds in the surface film have been confirmed by various methods (FT-IR [6, 7], XRD [8], SIMS [9], AES [10]). However, the relationship between the surface state of lithium and its morphology has not been completely explained. This may be due to the variety in the surface states of lithium used by each researcher (for example; as-received lithium foil [11], in situ cutting lithium wire [12], electrodeposited lithium [8], lithium prepared by vapour-deposition [13], amalgamated lithium [9], etc.). Moreover, another complication 584
moire等高技术在物体三维测量中的应用研究
（1）概述 工程上应用的 Moire 条纹，一般是由两块等间隔排列的直线族或曲线族（通常称为 计量光栅）叠合时产生的。当两块光栅重叠或一块光栅和它的像重叠时，栅线交点的轨 迹就是 Moire 条纹。图 1-1 显示密光栅重叠时的条纹图案。 Moire 条纹的形成原理，有几种不同的解释方法，一种是基于遮光阴影原理，这是 按照重叠线条交点的轨迹来表示 Moire 条纹的亮度分布。另一种是应用衍射干涉原理， 认为由条纹构成的新的亮度分布，可按衍射波之间的干涉结果来描述。亦有这种解释，
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绪论
1.1 概述 Moire 等高法三维测量课题的提出
物体的三维轮廓包含了物体的全部形状信息，因此，对物体三维轮廓的测量可使人 们更全面、深刻的认识物体。三维轮廓测量的原始方法是测量物体一系列离散点坐标， 再进行数学处理，得到粗糙的三维模型。随着计算机技术的快速发展，各种数学处理软 件的问世，各工业领域对复杂三维物体轮廓的快速、精确测量的要求越来越高。 在过去的三十多年时间里，三维表面测量技术已经成为科学分析、工业控制、生物 工程、生物医学以及材料学等方面研究的一种重要基本方法，出现了各种类型的三维表 面测量仪器。同时仪器的测量范围与分辨精度的比值不断增大，测量精确度经常可实现 微米级甚至纳米级。新的测量方法和测量仪器的不断出现，为人们更好的认识和掌握被 测对象的表面形貌和特性提供了新的有效手段。 Moire 条纹技术作为一种物体三维形貌的测量手段，具有无接触、非破坏性、测速 快、精度高等特点。而图像处理技术的快速发展有效的提高了 Moire 条纹法测量精度。 Moire 等高测量法作为一种易于实现的 Moire 条纹检测技术，具有广阔的应用前景。最 近些年， 在一些发达国家已经成熟的将 Moire 条纹技术应用到许多军民工程领域,而国内 发展缓慢，研究开发相关的实用技术是十分必要的。
MWCNTs_光热相变超滑表面的制备及防
表面技术第52卷第11期MWCNTs光热相变超滑表面的制备及防/除冰性能研究刘超a，钟涛a，张艳梅a*，杨晚生b（广东工业大学 a.材料与能源学院 b.土木与交通工程学院，广州 510006）摘要：目的制备光热相变超滑表面，并研究不同含量的多壁碳纳米管（MWCNTs）和固体石蜡对防冰/除冰性能的影响。
方法首先在纯Al表面刻蚀出微米结构，然后将MWCNTs、固体石蜡以及环氧树脂均匀混合后刮涂在处理后的Al基材表面，制备光热相变超滑表面，并对其润湿性、结冰/除冰性、机械稳定性以及自修复性进行表征。
结果通过扫描电镜对涂层截面表征发现MWCNTs已经完全均匀分布在涂层内部。
当用波长为808 nm、功率密度为0.5 W/cm2的近红外光（NIR）照射涂层，表层的固体石蜡融化成液体后水滴滑动角可由40°下降到5°，表现出极佳的滑动性能。
在–20 ℃时，与纯Al基底相比，相变超滑表面可将水滴的结冰时长从27 s延长至239 s，其冰黏附强度降也只有34.9 kPa。
得益于MWCNTs优异的光热性能，在NIR照射下，表面温度迅速升高，可在92 s内实现快速除冰。
此外，涂层在100次的循环摩擦后依然保持极低的冰黏附强度，并在NIR照射下可实现快速自修复。
结论光热相变超滑表面相比于纯Al表面具有更加优异的防冰性，MWCNTs的加入，使表面具有快速除冰性。
环氧树脂和固体石蜡则极大地提高了表面耐磨性以及自修复性，为长久的防冰/除冰提供了保障。
关键词：多壁碳纳米管；固体石蜡；相变超滑表面；光热效应；防冰/除冰；自修复中图分类号：TG178 文献标识码：A 文章编号：1001-3660(2023)11-0084-11DOI：10.16490/ki.issn.1001-3660.2023.11.007Preparation and Anti-icing/De-icing Performance of MWCNTsPhotothermal Phase-change Slippery SurfacesLIU Chao a, ZHONG Tao a, ZHANG Yan-mei a*, YANG Wan-sheng b(a. School of Materials and Energy, b. School of Civil and Transportation Engineering,Guangdong University of Technology, Guangzhou 510006, China)ABSTRACT: Icing on material surfaces often poses a great challenge to the production and daily life of people, so it is important to study passive anti-/de-icing coatings. In this paper, a Phase-Change Slippery Surface with photothermal conversion capability was developed and its anti-/de-icing properties were investigated with different contents of multi-walled carbon nanotubes (abbreviated as MWCNTs) as well as solid paraffin. Firstly, microstructures were etched on a pure aluminum (Al)收稿日期：2023-08-29；修订日期：2023-11-07Received：2023-08-29；Revised：2023-11-07基金项目：国家重点研发项目（2016YFE0133300）；广东省科技计划项目（2015A010105027）Fund：Supported by National Key Research and Development Project (2016YFE0133300); Guangdong Province Science and Technology Plan Program (2015A010105027)引文格式：刘超, 钟涛, 张艳梅, 等. MWCNTs光热相变超滑表面的制备及防/除冰性能研究[J]. 表面技术, 2023, 52(11): 84-94.LIU Chao, ZHONG Tao, ZHANG Yan-mei, et al. Preparation and Anti-icing/De-icing Performance of MWCNTs Photothermal Phase-change Slippery Surfaces[J]. Surface Technology, 2023, 52(11): 84-94.*通信作者（Corresponding author）第52卷第11期刘超，等：MWCNTs光热相变超滑表面的制备及防/除冰性能研究·85·surface using NaOH solution, and the etched aluminum was used as the substrate. MWCNTs, epoxy resin, and solid paraffin were mixed in varying mass ratios in a beaker. The MWCNTs were evenly dispersed in the mixed solution by stirring in a constant temperature water bath. Subsequently, the mixture was uniformly coated onto the substrate using a scraper and cured at high temperature to obtain the photothermal phase-change slippery surface. The wetting performance, ice formation/de-icing characteristics, ice adhesion strength, and mechanical stability were characterized. Characterization of the coating cross-section by scanning electron microscopy revealed that the MWCNTs have been completely and evenly distributed inside the coating.The contact angle of the solid-state slippery surface measured using a contact angle measurement device was found to be 111.6°.When illuminated with near-infrared light (NIR) with a wavelength of 808 nm and power density of 0.5 W/cm2, the MWCNTs absorbed the light energy and converted it into heat, melting the surface solid paraffin into a liquid state, thereby reducing the sliding angle of water droplets from 40° to 5°, showcasing exceptional sliding performance. To test the anti-icing performance on different surfaces, experiments were conducted in a constant temperature and humidity chamber set at –20 ℃. Compared to the pure aluminum substrate, the phase-change slippery surface extended the freezing time of water droplets from 27 s to 239 s, demonstrating excellent anti-icing performance. This can be attributed to two main factors: the reduced contact area between water droplets and the phase-change slippery surface, and the significantly lower thermal conductivity of the phase-change slippery surface compared to pure aluminum. Benefitting from the outstanding photothermal properties of MWCNTs, the surface temperature rapidly increased under NIR irradiation, enabling fast de-icing within 92 s. In contrast, pure aluminum exhibits very low photothermal conversion efficiency, and even under long-term NIR irradiation, its surface temperature does not increase significantly. The ice adhesion strength on the surface was measured using a digital force gauge and found to decrease to only 34.9 kPa. Additionally, after subjecting the surface to 100 cycles of friction on 400-grit sandpaper, minimal wear was observed. This can be attributed to the excellent abrasion resistance of epoxy resin and the lubricating properties of solid paraffin, effectively reducing frictional wear. Scratch marks on the surface were rapidly repaired under NIR irradiation, anda comparison of the contact angle and ice adhesion strength before and after the test revealed that the surface had restored itsperformance to pre-friction levels. In conclusion, the photothermal phase-change slippery surface has better anti-icing performance than pure aluminum, while the addition of carbon nanotubes enables rapid de-icing. The addition of epoxy resin and solid paraffin greatly improved the durability and self-repairing ability of the surface, thus providing long-lasting anti-icing/de-icing capabilities.KEY WORDS: MWCNTs; solid paraffin; phase-change slippery surfaces; photothermal effect; anti-icing/de-icing; self-repairing自然界以及工业生产中的积冰往往会给我们的生活带来不便，尤其在一些低温高湿的高海拔地区[1-3]。
在胶原上用EDC和NHS固定肝素
TISSUE ENGINEERINGVolume 10, Number 9/10, 2004©Mary Ann Liebert, Inc.Modulation of Angiogenic Potential of Collagen Matrices by Covalent Incorporation of Heparin and Loading with VascularEndothelial Growth FactorG.C.M. STEFFENS, Ph.D.,1C. YAO, M.D.,1,2P. PRÉVEL, M.D.,1,2M. MARKOWICZ, M.D.,2P. SCHENCK, Ph.D.,3E.M. NOAH, Ph.D., M.D.,2and N. PALLUA, Ph.D., M.D.2ABSTRACTOne of the prominent shortcomings of matrices for tissue engineering is their poor ability to sup-port angiogenesis. We report here on experiments to enhance the angiogenic properties of collagen matrices. Our aim is to achieve this goal by covalently incorporating heparin into collagen matri-ces and by physically immobilizing angiogenic vascular endothelial growth factor (VEGF) to the heparin. The immobilization of heparin was performed with 1-ethyl-3-(3-dimethylaminopropyl)-car-bodiimide (EDC) and N -hydroxysuccinimide (NHS). Carboxyl groups on the heparin are activated to succinimidyl esters, which react with amino functions on the collagen to zero length cross-links.This modification leads—in addition to the incorporation of heparin—to gross changes in in vitro degradation behavior and water-binding capacity. As a first approach to testing angiogenic capa-bilities, endothelial cells were exposed to nonmodified and heparinized collagen matrices. This ex-posure leads to an increase in endothelial cell proliferation. The increase can be further enhanced by loading the (heparinized) collagen matrices with VEGF. Evaluation of the angiogenic potential of heparinized matrices was further investigated by exposing them to the chorioallantoic membrane of chicken embryos and to the subcutaneous tissue of rats. Both approaches show that heparinized matrices have substantially increased angiogenic potential. In particular, the loading of heparinized matrices with VEGF invokes a further increase in angiogenic potential. It is apparent that the phys-ical binding of VEGF to heparin allows for a release that is beneficial to angiogenesis. By varying the heparin and EDC/NHS concentrations during the modification process and by varying the load-ing with VEGF, the angiogenic potential as well as the degradation behavior can be adapted to ob-tain matrices that fulfill specific angiogenic requirements in the field of tissue engineering.1502INTRODUCTIONENHANCEMENT OF THE ANGIOGENIC POTENTIALof im-plantable (bio)materials has received much atten-tion.1Because the angiogenic potential of most synthetic and natural materials is insufficient, many attempts havebeen made to enhance angiogenic potential either by changing the physicochemical parameters or by supple-mentation with angiogenic factors. Angiogenesis is the sprouting of new capillaries from preexisting vasculature and represents a complex multistep process that requires the adhesion, proliferation, and differentiation of endo-1Institute of Biochemistry 2Department of Plastic, Hand, and Burn Surgery, RWTH Aachen University, Aachen, Germany.3Dr. Suwelack Skin and Health Care, Billerbeck, Germany.thelial cells. Endothelial cell growth, proliferation, and differentiation depend on recruitment of specific integrins (a v 3) on the cell surface. These integrins must bind to their proper ligands in order to initiate distinct second-messenger pathways that finally lead to transformation into the angiogenic phenotype of endothelial cells.2In the present study, the angiogenic properties of ma-trices made of collagen are investigated. Collagen repre-sents a suitable substrate for cell attachment: it is bio-compatible and degrades into harmless products that are metabolized or excreted.3Collagen can be formed into three-dimensional matrices that are being applied as tis-sue substitutes or scaffolds for tissue regeneration.4The properties of collagen can be modified in many different ways.5,6Several authors claim that the covalent incorporation of glycosaminoglycans modifies the prop-erties of collagenous material. Thus Silver et al .7Wissink et al .,8,9and Tsai et al .10covalently linked heparin to col-lagenous films whereas Yannas and Burke 11and Pieper et al .12,13covalently incorporated chondroitin sulfate into collagen matrices. These modifications had positive ef-fects on in vivo blood compatibility and the proliferation of endothelial cells, respectively. Loading of heparinized collagen films with basic fibroblast growth factor (bFGF)in general leads to even stronger effects on the prolifer-ation of endothelial cells.14In our study we investigated the effects of the cova-lent incorporation of heparin into three-dimensional col-lagen matrices by 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide/N -hydroxysuccinimide (EDC/NHS). More-over, we report on the effects exerted by loading vascu-lar endothelial growth factor (VEGF) into these heparinized collagen matrices. Together these modifica-tions lead to a variety of collagen matrices in which the following parameters can be modulated: (1) angiogenic potential, (2) resistance to in vitro degradation with col-lagenase, and (3) moisture-binding capacity. These prop-erties may thus be modulated in order to adapt the col-lagenous matrices to specific requirements in the field of tissue engineering.MATERIALS AND METHODSCollagen matricesCollagen matrices were produced by Dr. Suwelack Skin & Health Care (Billerbeck, Germany). The matri-ces were obtained through lyophilization of collagen sus-pensions containing primarily collagen type I. The porous structure is nondirected and the pore sizes vary from 15to 25 m; the overall porosity amounts to ϳ98%.The collagen matrices were cut into cubes of either 5ϫ5ϫ5 mm (3.8–4.2 mg) or 10ϫ10ϫ10 mm (22–24 mg) and into circular specimens (diameter, 10mm; thickness, 2 and 5 mm).HEPARIN/VEGF-MODIFIED ANGIOGENIC POTENTIAL Heparin immobilizationHeparin immobilization was performed essentially as described in Hinrichs e t al .15and Wissink e t al .8Car-boxylic acid groups of heparin (Hep-COOH) were acti-vated with EDC and NHS. Heparin (sodium salt, 170 USP units/mg), EDC, and NHS were purchased from Sigma-Aldrich (St. Louis, MO). A typical modification experi-ment was performed as follows: 1 mg of heparin was ac-tivated with 1 mg of EDC per 0.6 mg of NHS in 500 L of 0.05 M 2-morpholinoethanesulfonic acid (MES) buffer (pH 5.6) for 10 min at 37°C, cubic collagen matrices (size, 5ϫ5ϫ5 mm) were immersed into the reagent so-lution, and the solution was evacuated to remove air from the matrices. After a reaction period of 4 h at 37°C, un-der gentle shaking, the heparinized collagen sponges were washed with 0.1 M Na 2HPO 4(pH 9.2) (2 h), 4 M NaCl (four times in 24 h) and deionized water (five times in 24 h). Finally, modified sponges were frozen at Ϫ80°C overnight (16 h), lyophilized, and stored at room tem-perature. Collagen matrices according to these parame-ters are designated H1E1 (1 mg of heparin and 1 mg of EDC per 0.6 mg of NHS per 500 L). The modification parameter H1E2 refers to 1 mg of heparin and 2 mg of EDC per 1.2 mg of NHS, and H0E0 refers to a collagen matrix that underwent all the procedures, except that no heparin and EDC/NHS were added.Determination of immobilized heparinThe amount of immobilized heparin was determined by toluidine blue assay.15,16Cubic collagen matrices (size, 5ϫ5ϫ5 mm; weight, 3.8–4.2 mg) were incu-bated with 5 mL of an aqueous solution of toluidine blue (0.1 M HCl, NaCl [2 mg/mL], and toluidine blue zinc chloride double salt, [0.4 mg/mL]; Sigma) for 4 h at room temperature, resulting in complexation of toluidine blue with heparin. Specimens were then washed five times with distilled water (10 mL/sample) in 24 h. Subse-quently, toluidine blue complexed to heparin was solu-bilized with 5 mL of a 1:4 (v/v) mixture of 0.1 M NaOH and ethanol. Absorbance of the resulting solution was de-termined at 530 nm after 1:5 dilution with the sodium hydroxide–ethanol solution. Standard curves were ob-tained according to the heparin solution assay protocol of Hinrichs et al .15Determination of free amino groups in heparinized collagen matricesThe residual number of free primary amino groups af-ter heparin immobilization was determined with trini-trobenzene sulfonic acid (TNBS). Collagen specimens were immersed in a mixture of 1 mL of 4 wt% NaHCO 3(pH 9) and 1 mL of 0.5% TNBS, and incubated overnight at 40°C. To this 3 mL of 6 M HCl was added and the so-lution was incubated at 60°C for another 1.5 h. After cool-1503ing to room temperature, 20 mL of anhydrous ethyl etherwas added for extraction of the excess TNBS and TNP-␣-amino acids17; this procedure was repeated at least five times. After 1:10 dilution with distilled water the ab-sorbance of the resulting solution was determined at 345nm. A control was prepared applying the same procedurewith the exception that HCl was added before the addi-tion of TNBS. The number of amino groups per 1000amino acids was obtained with the following formula: Free amino groupsϭ(absorbance at 345 nm)(0.05 L)MW/(1.46ϫ10,000 L/mol и cm)bx where MW is the molecular mass of the collagen (g/mol), 1.46ϫ10,000 L/mol иcm is the molar absorptivity of TNP-lysine, b is the cell path length (cm), and x is the sample weight (g).17In vitro degradation with collagenaseThe degree of degradation of heparinized collagensponges was determined by measuring sample weightsbefore and after degradation by collagenase fromClostridium histolyticum(type I; Worthington Biochem-icals, Lakewood, NJ). The original weights of specimens were determined after lyophilization. Modified and non-modified matrices were immersed in a solution contain-ing 40 or 200 units of collagenase in 1 mL of (PBS) buffer (pH 7.2) and incubated at 37°C under gentle shaking for the desired period of time. Degradation was stopped at specified time intervals by addition of 0.2 mL of a 0.25 M EDTA solution and the samples were cooled on ice for 10 min. Subsequently, the samples were washed with 5 mL of PBS buffer (pH 7.2, three times for 15 min each) and demineralized water (three times for 15 min each), frozen at Ϫ80°C (overnight), and lyophilized. After lyophilization, the weights of the residual samples were determined and the percentage of degradation at the spec-ified time interval t is calculated as follows: Degradation (%)ϭ(original weight Ϫ residualweight at time t)/(original weight/100) Moisture uptakeFor the analysis of moisture uptake the initial dryweights (W dry) of collagen matrix specimens (size, 5ϫ5ϫ5 mm; weight, 3.8–4.2 mg) were determined. Afterimmersion in PBS for 2 h at 37°C the weights of thewet specimens (W wet) were determined. Before theweighing process the wet matrices were brought intocontact with a piece of filter paper to remove looselybound moisture. Moisture binding was calculated ac-cording to the formulaMoisture uptake (mg/mg)ϭ(W wetϪW dry)ᎏᎏW drySTEFFENS ET AL.Exposure to endothelial cellsEndothelial cells were isolated from human umbilicalcords (human umbilical vascular endothelial cells[HUVECs] and cultivated in endothelial cell basalmedium (ECBM). For exposure experiments the secondpassage was used.In each well of a 6-well plate 100,000 HUVECs wereallowed to adhere for 1 day in 2 mL of ECBM (Cell-Systems, St. Katharinen, Germany). On day 2 collagenmatrices (cubes, 10ϫ10ϫ10 mm in size) modified ac-cording to the specified parameters were placed in thewells and the wells were filled with 2 mL of mediumwithout VEGF. Some of the matrices were loaded witha sterile solution (20 L) containing 100 ng ofrhVEGF165(R&D Systems, Minneapolis, MN). For ref-erence, one well of each plate was filled with ECBMonly. The cells were allowed to proliferate for 5 days,and on day 7 the matrices were removed and theHUVECs were trypsinized with EDTA–trypsin. Cellswere counted microscopically in a Neubauer chamber.To highlight changes in proliferation, cell numbers pres-ent on day 1 were subtracted from the observed numbersof cells.Chorioallantoic membrane assayFertilized chicken eggs were obtained from Bücher-hof (Horbach-Aachen, Germany). The chorioallantoicmembrane assay (CAM assay) was performed essen-tially as described in Zwadlo-Klarwasser e t al.18He-parinized and cross-linked collagen matrices were pre-pared according to the modification proceduresdescribed above and sterilized by immersion in 70%ethanol for 24 h. Sub-sequently they were equilibratedwith either PBS or serum-free ECBM under sterile con-ditions. In selected experiments 300 ng of rhVEGF165(R&D Systems) was loaded onto modified and non-modified matrices before exposure to chorioallantoicmembrane. Circular specimens of the various collagenmatrices (diameter, 12 mm; thickness, 2 mm) werecarefully placed on the chorioallantoic membrane andthe eggs were further incubated at 37°C for 7 days. Atthe end of this period, the chorioallantoic membraneswere either fixed in situ with 4% buffered formalin, ex-cised, and mounted on a slide, or the collagen speci-mens were dissected together with the surroundinggranulation tissue and processed for histological char-acterization.Quantitation of capillaries was carried out by countingthem at 50-fold magnification in three nonoverlappingareas. The average number of small vessels (diametersmaller than 20–40 m) in the defined areas was takenas an index for angiogenic potential after subtraction ofthe number of capillaries counted in the absence of anymatrix.1504Animal model experimentsCollagen matrices (diameter, 10 mm; thickness, 5 mm)modified according to the parameters described abovewere implanted in four dorsal subcutaneous pockets ofLewis rats, each implant 1 cm from the skin incision andwith 4 cm between them. The variously modified colla-gen matrices were implanted in animals either loadedwith 300 ng of recombinant rat VEGF 165or nonloaded.After 14 days of implantation the animals were killed andthe matrices were explanted. Explants were extensivelywashed with 1 mL of water for about 24 h and the hemeprotein content was determined spectrophotometrically atthe Soret band (absorbance, 410 nm).RESULTSIn an attempt to increase the angiogenic potential of collagen matrices by covalent incorporation of heparin and subsequent physical immobilization of VEGF, a se-ries of experiments was performed to evaluate heparin content after exposure of collagen matrices to heparin activated with 1-ethyl-3-(3-dimethylamino-propyl)-car-bodiimide (EDC)/N -hydroxysuccinimide (NHS). The ex-tent of heparin immobilization was determined with o -toluidine blue; this dye specifically binds to carboxyl groups.15After removal of excess dye by extensive wash-ing with water, the bound dye molecules were released by hydrolysis with NaOH and ethanol followed by quan-tification by absorption spectrophotometry.Figure 1 gives an overview of a number of properties of collagen matrices prepared according to a restrictedset of modification parameters (the modification param-eters are described in detail in Materials and Methods).In brief, the designation H1E0.5 refers to 1 mg of hep-HEPARIN/VEGF-MODIFIED ANGIOGENIC POTENTIAL arin and 0.5 mg of EDC (0.3 mg of NHS) being present in 500 L of the activation solution.The results of Fig. 1 show that the amount of heparinimmobilization clearly correlates with the concentrationof cross-linking reagents EDC and NHS in the solutionfor activating the carboxyl groups of heparin. The resultsobtained with the modification parameters H1E0 showthat adsorptive binding of heparin is negligible, appar-ently all physically bound heparin is removed during theextensive washing procedure. The amounts of immobi-lized heparin vary from 7 to about 40 g of heparin permilligram of collagen. It appears that with 2 mg of EDCa plateau is reached, and higher concentrations ofEDC/NHS do not lead to higher heparin-binding densi-ties.In addition to the covalent immobilization of the hep-arin to collagen, an additional cross-linking of collagen is likely to occur.14,19This additional cross-linking sub-stantially affects the resistance against degradation by collagenase.5,14We therefore subjected the same set of collagen matrices to in vitro degradation experiments.The results of these experiments are also shown in Fig.1. Whereas matrices modified at relatively low EDC con-centrations are substantially degraded, degradation per-centages with 40 units of collagenase for 2 h at 37°C vary from 60 to 30%. Matrices modified with EDC concen-trations equal to or greater than 1 mg of EDC per 500-L reaction volume clearly withstand degradation and the corresponding degradation percentages are on the or-der of 10% or less. A sharp increase in resistance againstdegradation was observed by increasing the EDC con-centration from 0.2 to 1.0%.To better understand the binding and cross-linking mechanisms we also investigated the number of available free ␣-amino groups (i.e., the number of available lysines and hydroxylysines) in the modified and non-modified1505FIG. 1.Extent of heparin immobilization and in vitro degradation as a function of increasing EDC/NHS-to-heparin weight ra-tios. Collagen matrices were modified and designated according to parameters specified in Materials and Methods. Degradation was carried out with 40 units of collagenase in 1 mL of PBS buffer for 2 h at 37°C. The columns show the mean values, and the error bars represent the corresponding standard deviations (n ϭ5).collagen matrices. Available amino groups were deter-mined with trinitrobenzenesulfonic acid (TNBS).17These results are given in Fig. 2. Within the set of modification parameters a continuous decrease of the number in free amino groups is observed, surprisingly, a sharp decrease of the number in free amino groups—as might be ex-pected from the degradation experiments—is not ob-served. The number of 35 free amino groups in non mod-ified collagen (H0E0) nicely corresponds to the number of lysines and hydroxylysines as deduced from the DNA-derived amino acid composition and amino acid analysis investigations.5The number of 21 free amino groups in the collagen matrix H1E4 demonstrates that in this case about 14 lysines and hydroxylysines per 1000 amino acids of collagen are involved in heparin binding and cross-linking.Another property of the modified collagen matrices that may be affected by heparin binding and/or additional cross-linking is the capability to take up moisture. The effects of the modification procedures on moisture up-take can also be deduced from Fig. 2: the moisture-bind-ing capacity of collagen matrices H1E2, H1E3, and H1E4 is almost twice as high as the moisture uptake of non-modified matrices. Above a concentration of 2 mg of EDC per 500-L reaction volume the moisture uptake seems to have reached a plateau.The angiogenic potential of the modified matrices was investigated by three different approaches. The first ap-proach focused on the change in proliferation rates of en-dothelial cells when they contact nonmodified and he-parinized collagen matrices. Figure 3 shows the results of a series of cell culture experiments with human um-bilical endothelial cells exposed to nonmodified (H0E0)STEFFENS ET AL. and heparinized (H1E0.2–H1E2) collagen matrices. To test the possible beneficial effect of loading VEGF onto these matrices, matrices were loaded with 50 ng of VEGF as indicated. The results clearly demonstrate that both the modification and the loading with VEGF have a sub-stantial impact on proliferation.The proliferation rate increases with increasing EDC/NHS concentrations and reaches a plateau at a con-centration of 1 mg of EDC per 500-L reaction volume. The additional effect exerted by loading with VEGF is clearly more prominent for collagen matrices modified by incorporation of heparin. The greatest effect is ob-served for H1E1 collagen matrices loaded with 50 ng of VEGF.As a second approach to evaluating the angiogenic po-tential of heparinized collagen matrices, we exposed the chorioallantoic membrane of chicken embryo18,20to non-modified and modified collagen matrices. Angiogenic potential was deduced from the density of microvessels (number per area) induced by the nonmodified and mod-ified collagen matrices. Microvessel densities already ob-served in the absence of any collagen matrix (control) were subtracted from the number of capillaries induced in the presence of the modified matrices. Figure 4 shows the number of observed capillaries and the increase in capillary density. The induction of angiogenesis increases with larger EDC-to-heparin ratios.In another set of experiments nonmodified (H0E0) and heparinized (H1E1) matrices were loaded with VEGF be-fore being exposed to the chorioallantoic membrane. Fig-ure 5 shows the observed number of capillaries and the calculated increases induced by loading H0E0 and H1E1 matrices with VEGF.1506FIG. 2.Free amino groups per 1000 amino acids and moisture uptake as a function of increasing EDC/NHS-to-heparin weight ratios. Collagen matrices were modified and designated according to parameters specified in Materials and Methods. Free amino groups were determined with trinitrobenzenesulfonic acid (TNBS). Columns show the mean values, and error bars represent the corresponding standard deviations (nϭ5).The effects on angiogenic potential were also investi-gated in animal model experiments with rats. Nonmodi-fied and heparinized specimens were either loaded with 300 ng of VEGF or nonloaded and subcutaneously im-planted in pockets prepared on the back of Lewis rats.The specimens were explanted after 14 days and evalu-ated for their heme protein contents. These experiments were restricted to nonmodified (H0E0) and collagen ma-trices modified according to the parameters H1E1.Figure 6 shows the hemoglobin contents of the corre-sponding explants. Heparinized matrices demonstrated substantially increased vascularization, which could beHEPARIN/VEGF-MODIFIED ANGIOGENIC POTENTIALfurther enhanced by loading the heparinized matrices with VEGF. In the case of nonmodified collagen matrix the additional beneficial effect of VEGF loading remains relatively small.DISCUSSIONThe covalent incorporation of heparin into collagen matrices has been investigated in order to develop colla-gen matrices with enhanced angiogenic potential. Figures 1 and 2 compile a series of biochemical and biophysical1507FIG. 3.Induction of proliferation of human umbilical vein endothelial cells (HUVECs) by exposure to nonmodified (H0E0)and modified (H1E0.2–H1E2) collagen matrices. Matrices were either nonloaded or loaded with 50 ng of rhVEGF 165. The ex-periments were carried out as described in Materials and Methods. The increase in the number of cells was obtained by sub-tracting the number of cells at the start of the experiment (100,000). Columns show the mean values, and error bars represent the corresponding standard deviations (n ϭ3).FIG. 4.Angiogenic effect exerted by implantation of collagen matrices into the chorioallantoic membrane of chicken embryos.Collagen matrices were modified and designated according to parameters specified in Materials and Methods. Capillaries were counted as described in Materials and Methods. The increase in number of capillaries was obtained by subtracting the number of capillaries in the control experiments. Columns show the mean values, and error bars represent the corresponding standard deviations (n ϭ5).characterizations of modified matrices. The immobiliza-tion of heparin almost linearly increases with the con-centration of EDC/NHS in the reaction mixture. Values vary from 10 to about 40 g/mg of collagen and appear to reach a maximum at concentrations in excess of 1 mg of EDC per 500-L reaction volume. Resistance to in vitro degradation with collagenase sharply increases at EDC concentrations in excess of 0.2 mg of EDC per 500-L reaction volume. We explain this observation as fol-lows: at relatively low concentrations of heparin, most of the EDC/NHS is used for the activation of carboxyl groups on the heparin molecules, and thus fewer EDC/NHS molecules are available for the additional cross-linking of collagen fibrils. When the EDC/NHS concentration exceeds 0.2 mg/500-L reaction volume,more cross-linking molecules remain available for addi-tional cross-linking of collagen fibrils. This process leads to a sharp decrease in the degradation percentages. In-creasing heparin-to-EDC ratios lead to both lower hep-arin incorporation and lower additional cross-linking;thus H2E1 incorporates less heparin and is degraded more rapidly (data not shown).The number of free amino groups consistently decreases with increasing EDC/NHS concentrations, the largest re-duction of free amino groups being observed on increasing the EDC/NHS concentration from 3 to 4 mg/500-L reac-tion mixture. This may be explained by the fact that in this case only a small amount of EDC/NHS is consumed for the activation of heparin, and thus all the extra EDC/NHS molecules are available for cross-linking of collagen.The evaluation of angiogenic potential by three indepen-dent approaches shows that the heparinized matrices induce greater angiogenic effects. The exposure of HUVECs to he-parinized matrices clearly leads to higher proliferation rates,and loading of these matrices with VEGF further increases the proliferation rates. The most prominent effect was ob-served with collagen matrices modified according to the pa-rameters H1E1 and loaded with VEGF (Fig. 3).Similar effects were observed by exposing chicken em-bryo chorioallantoic membrane to heparinized collagen matrices. Again H1E1 collagen matrices loaded with VEGF induced significantly greater angiogenic effects (Figs. 4 and 5).Subcutaneous implantation of nonmodified and he-1508FIG. 5.Angiogenic effects of loading 100 ng of rhVEGF 165into nonmodified (H0E0) and heparinized (H1E1) collagen ma-trices. Angiogenic effects were evaluated by implanting collagen matrices—either loaded or nonloaded—into chicken embryo chorioallantoic membranes. Capillaries were counted as described in Materials and Methods. The increase in the number of cap-illaries was obtained by subtracting the number of capillaries in the control experiments. Columns show the mean values, and error bars represent the corresponding standard deviations (n ϭ5).FIG. 6.Angiogenic potential of modified and nonmodified collagen matrices as evaluated by subcutaneous implantation in rats. Collagen matrices were modified and designated accord-ing to parameters specified in Materials and Methods. Matrices were either loaded with 300 ng of rhVEGF 165or nonloaded.Angiogenesis was evaluated by determining the hemoglobin content of matrices, which were explanted after 14 days.Columns show the mean values, and error bars represent the corresponding standard deviations (n ϭ2).parinized matrices in animal model experiments allowed for alternative in vivo evaluation with closer proximity to the final clinical indication. Angiogenic potential was evaluated by determining the hemoglobin absorbance of wash solutions of each specimen, explanted after 14 days.As evaluated by this approach, heparinized matrix H1E1loaded with VEGF again showed the greatest increases in angiogenic effect.Because the applied approaches do not allow state-ments on the quality of the vasculature within the im-plants we are currently evaluating explants from the in vivo experiments by immunohistochemistry. Further-more, it would be worth investigating to what extent and by which parameters the additional cross-linking is in-fluencing the angiogenic outcome of the modifications described in this article.ACKNOWLEDGMENTSThis work was supported by grant 0312692 from the Bundesministerium für Bildung und Forschung (Berlin,Germany) to Dr. Suwelack Skin and Health Care AG (Billerbeck, Germany) and by grant TV B 47 from the Interdisciplinary Centre for Clinical Research Biomat of the Medical Faculty of RWTH Aachen University (Aachen, Germany).REFERENCES1.Nomi, M., Atala, A., Coppi, P.D., and Soker, S. Principles of neovascularization for tissue engineering. Mol. Aspects Med. 23,463, 2002.2.Hall, H., Baechi, T., and Hubbell, J.A. Molecular proper-ties of fibrin-based matrices for promotion of angiogene-sis in vitro . Microvasc. Res. 62,315, 2001.3.Friess, W. Collagen: Biomaterial for drug delivery. Eur. J.Pharm. Biopharm. 45,113, 1998.4.Yannas, I.V., Burke, J.F., Orgill, D.P., and Skrabut, E.M.Wound tissue can utilize a polymeric template to synthe-size a functional extension of skin. Science 215,174, 1982.5.Zeeman, R., Cross-linking of collagen-based materials [Ph.D. thesis]. University of Twente, Enschede, The Netherlands, 1998.6.Zeeman, R., Dijkstra, P.J., van Wachem, P.B., van Luyn,M.J., Hendriks, M., Cahalan, P.T., and Feijen, J. Succes-sive epoxy and carbodiimide cross-linking of dermal sheep collagen. Biomaterials 20,921, 1999.7.Silver, F.H., Yannas, I.V., and Salzman, E.W. Glycosami-noglycan inhibition of collagen induced platelet aggrega-tion. Thromb. Res. 13,267, 1978.8.Wissink, M.J., Beernink, R., Pieper, J.S., Poot, A.A., En-gbers, G.H., Beugeling, T., van Aken, W.G., and Feijen, J.Immobilization of heparin to EDC/NHS-crosslinked colla-gen: Characterization and in vitro evaluation. Biomaterials 22,151, 2001.9.Wissink, M.J., Beernink, R., Poot, A.A., Engbers, G.H.,Beugeling, T., van Aken, W.G., and Feijen, J. ImprovedHEPARIN/VEGF-MODIFIED ANGIOGENIC POTENTIAL endothelialization of vascular grafts by local release of growth factor from heparinized collagen matrices. J. Con-trol. Release 64,103, 2000.10.Tsai, C.C., Chang, Y., Sung, H.W., Hsu, J.C., and Chen,C.N. Effects of heparin immobilization on the surface char-acteristics of a biological tissue fixed with a naturally oc-curring crosslinking agent (genipin): An in vitro study. Bio-materials 22,523, 2001.11.Yannas, I.V., and Burke, J.F. Design of an artificial skin. I.Basic design principles. J. Biomed. Mater. Res. 14,65, 1980.12.Pieper, J .S., van Wachem, P.B., van Luyn, M.J.A.,Brouwer, L.A., Hafmans, T., Veerkamp, J.H., and van Kup-pevelt, T.H. Attachment of glycosaminoglycans to col-lagenous matrices modulates the tissue response in rats.Biomaterials 21,1689, 2000.13.Pieper, J.S., Hafmans, T., Veerkamp, J.H., and van Kup-pevelt, T.H. Development of tailor-made collagen–glycos-aminoglycan matrices: EDC/NHS crosslinking, and ultra-structural aspects. Biomaterials 21,581, 2000.14.Wissink, M.J., van Luyn, M.J., Beernink, R., Dijk, F., Poot,A.A., Engbers, G.H., Beugeling, T., van Aken, W.G., and Feijen, J. Endothelial cell seeding on crosslinked collagen:Effects of crosslinking on endothelial cell proliferation and functional parameters. Thromb. Haemost. 84,325, 2000.15.Hinrichs, W.L.J., ten Hoopen, H.W.M., Wissink, M.J.B.,Engbers, G.H.M., and Feijen, J. Design of a new type of coating for the controlled release of heparin. J. Control. Re-lease 45,163, 1997.16.Sano, S., Kato, K., and Ikada, Y. Introduction of functional groups onto the surface of polyethylene for protein immo-bilization. Biomaterials 14,817, 1993.17.Bubnis, W.A., and Ofner, C.M., III. The determination of ⑀-amino groups in soluble and poorly soluble proteinaceous materials by a spectrophotometric method using trini-trobenzenesulfonic acid. Anal. Biochem. 207,129, 1992.18.Zwadlo-Klarwasser, G., Görlitz, K., Hafemann, B., Klee,D., and Klosterhalfen, B. The chorioallantoic membrane of the chick embryo as a simple model for the study of the angiogenic and inflammatory response to biomaterials. J.Mater. Sci. Mater. Med. 12,195, 2001.19.van Wachem, P.B., Plantinga, J .A., Wissink, M.J .,Beernink, R., Poot, A.A., Engbers, G.H., Beugeling, T., van Aken, W.G., Feijen, J., and van Luyn, M.J. In vivo bio-compatibility of carbodiimide-crosslinked collagen matri-ces: Effects of crosslink density, heparin immobilization,and bFGF loading. J. Biomed. Mater. Res. 55,368, 2001.20.Soker, S., Machado, M., and Atala, A. Systems for thera-peutic angiogenesis in tissue engineering. World J. Urol.18,10, 2000.Address reprint requests to:G.C.M. Steffens, Ph.D.Department of Biochemistry and Molecular CellBiologyInstitute of Biochemistry RWTH Aachen UniversityPauwelsstrasse 3052074 Aachen, GermanyE-mail:gcm.steffens@post.rwth-aachen.de1509。
金属高密勒指数表面能和表面结构的分子动力学研究
按照啥鬻森静定义，瑟稳“徽缍稳”，是攒掰有熬力学菲平衡态懿菇牾续稿在 空间分布的集合：其空间尺寸可以从纳米（如非平衡态的杂质原子）到数米爨级 （粥样品表蕊情况），所对瘟豹对蔺尺度可敬瓢死ｐｓ（原子渤力学过程）蓟几年
（例如，腐蚀、蠕变和疲劳等过程）。从定量上弄清楚材料宏观性质与微观缡构 之间的关系，一直是材料科学研究的一个主要目标。臻实现这一目标，必须确定 和撼迷对榜瓣性质考燕要搏髑的鑫掺缺陷，以及晶掺缺照的黪态襄动态特性。表 １－１熄不同晶格缺陷所确立的微结构体系与其特征尺度之间的对应关系。
郑州大学 硕士学位论文 金属高密勒指数表面能和表面结构的分子动力学研究 姓名：王晓春 申请学位级别：硕士 专业：凝聚态物理 指导教师：贾瑜;胡行
20040501
摘要
金属和半导体材料的高密勒指数表面怒目前表面科学研究的～个热点问题， 也是毽霉更避一步萋秀究鳃阉题，曩｛ｌ｛｝戆磅突主要集中在对袭覆见秘终掏熬确定， 本文根据目前实验上对一些表面已有的研究结果，在理论上对一些愈属的高密勒 指数表面静袭面能翻表面结构送行了研究。采焉半经验嵌入原予势（ＥＡＭ）静分子 动力学方法，计算了具有理想面心立方结构的金属Ａ１、Ｃｕ、Ｎｉ的ｆ００１１晶带（范 围从０００）面至（１１０）街）和卜１１０］晶带（范围从０１０）丽至（１１１）面再到（００１）面） 的袭面能值随角度０的变化曲线。以及理想体心立方结构的金属Ｆｅ的ｆ００Ｕ晶带
表Ｉ－２越糕模拟中的各耱方法与空间尺度（纳观§《微溉层次）的对应美系
空间尺度／ｍ 模拟方法 １０。。１０．６ Ｍｅｔｒｏｐｏｌｉｓ蒙特卡罗
典型应用 热力学、扩散及有序化系统
王Ｏ’撙押１０—６ 懿函变努法（或嚣窝簇变分法）
高强钢激光穿透焊熔池温度场数值模拟
收稿日期:2008-02-18第28卷第3期应 用 激 光Vo l.28,N o.32008年6月APPLIED LASERJune 2008高强钢激光穿透焊熔池温度场数值模拟陈军城, 俞海良, 芦凤桂, 唐新华(上海交通大学上海市激光制造与材料改性重点实验室,上海200240)提要 深入分析了激光焊接小孔传热模型的特点,选取指数衰减热源模型建立了高强钢激光穿透焊接熔池温度场三维数值模型。
利用A N SYS 有限元分析软件对激光焊接温度场进行数值模拟,并且通过CP800钢激光焊接试验验对模型进行了修正。
计算所得的熔池截面与试验结果吻合良好,这验证了本文所建高强钢激光穿透模型的可靠性。
关键词 高强钢; 激光焊接; 温度场; 数值模拟Num erical Simu lation for T empe ratu re Fie ld in Molten Pool of Dee p P enetration Laser W elding of High S trength S teelChen Juncheng , Y u H ailiang, L u F eng gui, T ang X inhua(Shanghai J iao Tong Univer sity Shanghai key Laborator y of Mater ials L aser Pr ocessing and Modif ication,Shanghai 200240,China )Abstract T he char acter of keyho le model in deep penetr atio n laser w elding is deeply analy zed.Based on that,the appro pr iate three -dimensional mathematical mo del fo r the t emperat ur e field w ere dev eloped accor ding t o an ex po nential attenuatio n heat -source mo del.By using AN SYS,laser welding temperature fields ar e simulated and the suitability o f the model w as mo dif ied by laser w elding of CP 800steel.Calculated r esult s fro m the models ar e found to agr ee w ith t he experimental r esults for the geome -try pr ofile of w eld,w hich has also validat ed the dependability o f the abov e -mentioned mo del.Key words H ig h st rength steel; laser w elding; temperature field; numer ical simulat ion1 引言激光焊接作为一门新的材料加工技术,与传统的焊接方法相比具有非接触、无污染、低噪音、高效率等优点。
激光焊透和焊接现象的解释
第36 卷第12 期中国激光V ol36, No. 12 2009 年12 月CHINESE JOURNAL OF LASERS December, 20091文章编号: 0258- 7025( 2009) 12-3160- 07激光焊透和焊接现象的解释(特约论文)Seiji Katayama* Youske Kawahito(缝接和焊接研究所,大阪大学,567 - 0047年大阪,日本)Corr esponding author : katayama @jwri. osaka-u . ac. Jp接收2009年10月13日摘要深入渗透焊接可以由一个高能量密度的激光器产生。
而影响激光焊透的因素,有焊缝熔深，激光诱导和激光束之间的相互作用，锁孔是熔体在熔化池中流动的一种行为，并且有气泡和孔隙的产生，阻止了勘察。
因此，对等离子体焊缝熔深的效果由CO2激光器和光纤激光器焊接进行解释分别。
飞溅，底部填充，驼峰的形成的理解。
可以被容易地确认形成在高功率和低的焊接速度，由于许多气泡的产生从该孔隙率尖的。
关键词激光焊接；CO2激光器；光纤激光；激光焊接现象；焊缝熔深1引言激光焊接已经获得了极大的普及，有前途的高品质连接技术，高精度，高性能，高速度，好的柔韧性，以及低的变形或失真，除了容易识别还可以广泛的应用。
一个机器人，减少电源蒸发增强散热，全自动化，系统化，生产化等[1]。
激光焊接的应用是逐渐增加。
激光器的缺陷或缺点，使其激光焊接的成本高，高度反射或高难熔塞尔玛导电金属，小间隙公差，易形成焊接，如波河缺陷- 孔隙度在深深地渗透焊缝熔合区。
因此，要了解CO2，YAG，或光纤激光器焊缝熔深的机制和现象，各种研究已有进行有关激光诱导行为，激光束和其之间的相互作用诱导等离子，熔体流动，锁孔沟通对话折射率和气泡产生的熔池铅的孔隙形成的焊缝熔合区[2〜26]。
2实验方法高功率CO2，YAG或光纤激光器的焊接是在304型奥氏体少钢或铝合金板上染色进行的，并且其焊透和焊接现象进行了对比。
电动机英语作文
电动机英语作文篇一：电动机专业英语inductionmachine感应式电机horseshoemagnet马蹄形磁铁magneticfield磁场eddycurrent涡流right-handrule右手定则left-handrule左手定则slip转差率inductionmotor感应电动机rotatingmagneticfield旋转磁场winding绕组stator定子rotor转子inducedcurrent感生电流time-phase时间相位excitingvoltage励磁电压solt槽lamination叠片laminatedcore叠片铁芯short-circuitingring短路环squirrelcage鼠笼rotorcore转子铁芯cast-aluminumrotor铸铝转子bronze青铜horsepower马力random-wound散绕insulation绝缘acmotor交流环电动机endring端环alloy合金coilwinding线圈绕组form-wound模绕performancecharacteristic工作特性frequency频率revolutionsperminute转/分motoring电动机驱动generating发电per-unitvalue标么值breakdowntorque极限转矩breakawayforce起步阻力overhauling检修wind-drivengenerator风动发电机revolutionspersecond转/秒numberofpoles极数speed-torquecurve转速力矩特性曲线plugging反向制动synchronousspeed同步转速percentage百分数locked-rotortorque锁定转子转矩full-loadtorque满载转矩primemover原动机iushcurrent涌流magnetizingreacance磁化电抗line-to-neutral线与中性点间的staorwinding定子绕组leakagereactance漏磁电抗no-load空载fullload满载Polyphase多相(的)iron-loss铁损compleximpedance复数阻抗rotorresistance转子电阻leakageflux漏磁通locked-rotor锁定转子choppercircuit斩波电路separatelyexcited他励的compounded复励dcmotor直流电动机demachine直流电机speedregulation速度调节shunt并励series串励armaturecircuit电枢电路opticalfiber光纤interoffice局间的waveguide波导波导管bandwidth带宽lightemittingdiode发光二极管silica硅石二氧化硅regeneration再生,后反馈放大coaxial共轴的,同轴的high-performance高性能的carrier载波mature成熟的SingleSideBand(SSB)单边带couplingcapacitor结合电容propagate传导传播modulator调制器demodulator解调器linetrap限波器shunt分路器amplitudemodulation(am调幅FrequencyShiftKeying(FSK)移频键控tuner调谐器attenuate衰减incident入射的two-wayconfiguration二线制generatorvoltage发电机电压dcgenerator直流发电机polyphaserectifier多相整流器boost增压timeconstant时间常数forwardtransferfunction正向传递函数errorsignal误差信号regulator调节器stabilizingtransformer稳定变压器timedelay延时directaxistransienttimeconstant直轴瞬变时间常数transientresponse瞬态响应solidstate固体buck补偿转子：转轴：shaft换向器：commutator铁芯：rotorsteelcore端板：endspider 绝缘纸：rotorsteelliner槽楔（环）：wedgeringU型挡圈：Utyperetainer 漆包线：fieldmagnetwire轴承：bearing绝缘漆：varnish换向片：commutatorsegment定子：铁芯：rotorsteelcore漆包线：fieldmagnetwire绝缘纸：rotorsteelliner 支架：bracket支撑组件：机壳：housing端盖：supportframe碳刷组件：碳刷：brush碳刷套：brushsleeve碳刷架(刷握)：brushholder弹簧：brushspring刷辫：brushflexible刷盒：brushbox篇二：电机行业英语电机（马达）electricmotor,微电机micromotor小电机smallmotor分马力电机fractionalhorsepowermotor空调暧通电机HVacmotor(heating,ventilatingair-conditioningmotor)直流电机directcurrentmotor,dcmotor串励直流电机serieswounddcmotor并励直流电机shuntwounddcmotor复励直流电机compoundwounddcmotor直流无刷电机Brushlessdirectcurrentmotor,BLdcmotor串激电机universalmotor交流电机alternatingcurrentmotor,acmotor齿轮电机Gearedmotor,Gearmotor同步电机synchronousmotor异步电机asynchronousmotor,inductionmotor罩极电机shadedpolemotor步进电机stepmotor,steppermotor,steppingmotor混合式hybrid磁阻式variablereluctance永磁式permanentmagnet步距角精度stepangleaccuracy转轴shaft轴向负载axialload轴向窜动axialendplay径向跳动radialrunout负载onload 过载overload额定负载ratedload空载no-load电流current电压voltage 防护等级protectionclass,degreeofprotection,isolationclass绝缘等级insulationclass力距torque起动力距startingtorque最大(崩溃)转距breakdowntorque堵转lockedrotor保持力距holdingtorque共振resonance电线（电缆）cable测试程序testproc(转载于: 爱作文网)edure性能测试performancetest耐压测试dielectrictest(highpottest)功能测试functionalitytest,functiontest实地测试fieldtest寿命测试lifetest老化试验ageingtest连续运转continuousduty,continuousrunning间歇运转intermittentduty,intermittentrunning温升试验temperaturerisetest环境温度ambienttemperature峰值peakvalue供应商supplier,vendor,seller客户customer,client,buyer样品（样机）prototype,sample试生产pilotproduction,try-outproduction小批生产pre-seriesproduction批量生产seriesproduction打筋spline滚花knurl攻丝tap键槽keyway定位销stoppin螺钉screw 螺纹thread螺栓bolt螺母nut联结器（接插件）connector端子：terminal标签,铭牌labelnameplate 外形尺寸outsidedimensionoutline精度accuracy公差tolerance不符合要求non-conformity,outofspecification前端盖frontflange,frontendcover,frontendbell,frontendshield后端盖rearflange,rearendcover,rearendbellrearendshield凸台pilot齿轮，带轮pinion,gearwheel,gear滚珠轴承ballbearing含油轴承sleevebearing,bronzebearing,selflubricatingbearing转子rotor定子stator铁芯core电枢armature磁钢magnet整流子（换向器）commutator碳刷carbonbrush,brush刷握brushholder机壳housing/shell轴承室bearinghousing出轴shaftextension扁丝flat工装、夹具jigs,fixtures,tooling规gauge 引出线leadwire,leads线路板PcB(printedcircuitboard)驱动器driver,drive冲片lamination槽slot齿teeth轭yoke硅钢片siliconsteel漆包线copperwire/enamelinsulatedcopperwire胶带tape压铸diecasting注塑mouldinjection波纹垫圈wavewasher车加工machining精车：turning霍尔传感器hallsensor开关switch装配assemble,assembly生产制造make,manufacture,produce动平衡balance.balancing热处理heattreatment表面淬火casehardening穿透淬火throughhardening退火annealing正火temper表面涂覆surfacecoating 喷砂sandblast涂胶gluing滴漆varnish电泳powdercoatingE-coating 力矩速度曲线speedtorquecurve磁通flux工艺流程图processflowchart 绝缘骨架plasticbobbin止口rabbet粗糙度roughness同心度concentricity偏心度eccentricity垂直度perpendicularity平行度parallelismabscissaaxis横坐标acmotor交流电动机activecomponent有功分量activeinrespectto相对呈阻性actualvalue,effectivevalue有效值acyclicmachine单极电阻adjustable-speedrange调速范围admittance导纳airgap气隙air-gapfluxdistribution气隙磁通分布air-gapflux气隙磁通air-gapline气隙磁化线air-gapreluctance气隙磁阻algebraic代数的algorithmic算法的alternatingcurrentmotor交流电动机ampere-turns安匝(数)amplitudemodulation(am)调幅anglestability功角稳定arc,electricarc电弧armaturecircuit电枢电路armatureconductor电枢导体armaturecoil电枢线圈armaturem.m.f.wave 电枢磁势波armaturereaction电枢反应armaturereactionreactance电枢反应电抗armatureiron电枢铁心asynchronousmotor异步电机asymmetry不对称automaticV oltageregulator(aVR)自动电压调整器auxiliarymotor辅助电动机axiallyandcircumferentially轴向和环向axialmagneticattraction轴向磁拉力bandwidth带宽base基极basicfrequencycomponent基频分量bastpressure风压beltfactor分布系数bilateralcircuit双向电路bimotored 双马达的biphase双相的breakawayforce起步阻力breakdowntorque极限转矩bronze青铜brush电刷brushvoltagedrop电刷压降brushspacing电刷间距capacitance电容carrier载波cartesiancoordinates笛卡儿坐标系can屏蔽套cast-aluminumrotor铸铝转子centrifugalforce离心力characteristicfrequency固有频率choppercircuit斩波电路circuitbranch 支路circuitcomponents电路元件circuitdiagram电路图circuitparameters电路参数circumferentialorientationmotor切向永磁电机criticalwhirlingspeed临界转速claw-poles爪极电机closedloop闭环closedslot闭口槽coaxial共轴的,同轴的coggingtorque齿槽转矩coilwinding线圈绕组coincideinphasewith与….同相collector集电极commutatingpole,interpole换向极commutatorsegment换向片commutator-brushcombination换向器-电刷总线compensatingwinding 补偿绕组compensatingcoil补偿线圈compleximpedance复数阻抗compoundgenerator复励发电机compounded复励conductance电导conductor导体converter变流器copperloss铜耗correctioncoefficient 校正系数corridor通路counter-clockwise逆时针couplingcapacitor耦合电容currentattenuation电流衰减currentdensity电流密度currentgain 电流增益currentphasor电流相量currentstrength电流强度currentvector电流矢量dampingcage阻尼笼dcgenerator直流发电机dcmotor直流电动机demachine直流电机differentiation微分digitalsignalprocessor(dSP)数字信号处理器directaxistransienttimeconstant直轴瞬变时间常数direct-axistransientreactance直轴瞬态电抗direct-axiscomponentofvoltage电压直轴分量directaxis直轴direct-current直流directtorquecontrol(dTc)直接转矩控制displacementcurrent位移电流distributedwinding分布绕组distributionfactor分布因数distoritionofvoltagewaveshape电压波形畸变domain磁畴duty,load负荷dynamicresponse动态响应dynamic-stateoperation动态运行3dequivalentmagneticcircuitnetworkmethod三维等效磁路网络法3d-Emcne.m.f=electromotivefore电动势eddycurrent涡流effectivevalues有效值effectsofsaturation饱和效应electricenergy电能electricaldevice电气设备electromagneticinduction电磁感应electromagneticpower电磁功率elecironagneticclamping电磁阻尼electricpotential电位electricalfield电场electromotiveforce电动势electromagneticforce电磁力electromagneticwave电磁波electrode电极电焊条electromagnetictorque 电磁转矩endring端环endturn端部绕组endcover端盖endring端环endleakagereactance端部漏抗equivalentT–circuitT型等值电路excitationsystem励磁系统excitingvoltage励磁电压externalarmaturecircuit电枢外电路externalcharacteristic外特性fan风扇feedbackcomponent反馈元件feedbackloop反馈回路feedbacksignal反馈信号feedbacksystem反馈系统feedforwardsignal前馈信号feedforwardsystem前馈系统ferromagnetic铁磁材料fieldcoils励磁线圈fieldcurrent励磁电流fieldeffecttransistor(FET)场效应管fieldorientedcontrol(Foc)磁场定向控制fieldwinding磁场绕组，励磁绕组flatcable扁电缆fluxlinkage磁链fluxline磁通量fluxpath磁通路径fluxpulsation磁通脉冲flucdensity磁通密度fluxdistribution磁通分布forwardtransferfunction 正向传递函数fractionalpitch短节距frequency频率frequencyconversion变频frequencychangerset变频机组fringingeffect边缘效应fullload满载full-loadtorque满载转矩full-pitchwinding整距绕组fundamentalwave基波fundamentalcomponent基波分量gain增益generatorvoltage发电机电压grade等级harmonic谐波horsepower(HP)马力horseshoemagnet马蹄形磁铁hysteresisloss磁滞损耗idealsource理想电源imbricatedwinding,lapwinding叠绕组impedance阻抗impedancedrop阻抗压降impulsevoltagepeakvalue冲击电压峰值inductance电感inductiongenerator感应发电机inductionmachine感应电机inductionmotor感应电动机inductivecomponent感性（无功）分量inherentregulationofgenerator发电机固有电压调整率instanttorgue瞬态转矩instantaneouselectricpower瞬时电功率instantaneousmechanicalpower瞬时机械功率insulation绝缘insulationresistance绝缘电阻intensityofelectrialfield电场强度interturnbreakdownvoltage匝间击穿电压interturninsulating匝间绝缘interturnvoltageresistanttest匝间耐压试验interiorPermanentmagnet(iPm)内置式SurfaceinsetPermanentmagnet(SiPm)表面式internalresistance内阻inverter逆变器ironcore铁心iron-loss铁损lamination叠片laminatedcore叠片铁心laminationinsalation冲片绝缘lag滞后leadingcurrent超前电流leadingpowerfactor超前功率因数leakagecurrent漏电流leakageflux漏磁通leakagereactance漏磁电抗leakage泄漏left-handrule左手定则liftmotor电梯用电动机lightemittingdiode发光二极管lightningshielding避雷linecurrent线电流linevoltage线电压linearzone 线性区linear-motionmachine直线电机linearinductionmotor直线感应电机line-to-neutral线与中性点间的loadcharacteristic负载特性loadpowerfactor负载功率因数load-saturationcurve负载饱和曲线locked-rotortorque锁定转子转矩locked-rotorcurrent堵转电流longpithwinding长距绕组long-pithcoil长距线圈magneticamplifier磁放大器magneticcircuit磁路magneticcoupling磁耦合magneticfield磁场magneticflux磁通magnetichysteresis(creeping)磁滞magnetichysteresisloop磁滞回线magneticinduction磁感应magneticloading磁负荷magneticparticle磁粉离合器magneticpole磁极magneticsaturation磁饱和magnetictorque电磁转矩magneticyoke磁轭magnetizingreacance磁化电抗magnetizationcurve磁化曲线magnetomotiveforce(m.m.f)磁动势mainpole主极mesh网孔mid-frequencyband中频带modulator调制器modulus模motoring电动机驱动motorslip电动机转差率m.m.fwave 磁势谐波mutualflux交互(主)磁通mutual-inductor互感negativephase-sequence 负序no-load空载nominalpull-intorque标称牵入转矩non-sinusoidal非正弦numberofpoles极数numberoffieldturns磁极绕组匝数numberofslots槽数odd-orderharmonic 奇次谐波operatingpoint工作点operatingcharacteristiccurve运行特性曲线opticalfiber光纤oscillation振荡oscilloscope示波器outsidediameterofcore铁心外径overhangleakagepermeance端部漏磁导overload超负荷overlapping重叠parallel并联parallelconnexionmagnetizedwinding并励绕组parallelconnexionroadnumber并联支路数parallelwindnumber并绕根数pancakecoil扁平绕组P.d.=potentialdrop电压降peaktopeak峰峰值perunitvalue标么值percentage百分数peripheralair-gapleakage磁极漏磁performancecharacteristic工作特性permanentmagnet永磁体permanentmagnetsynchronousmotor永磁同步电机permeability导磁率periodicallysymmetrical周期性对称per-unitvalue标么值phasedisplacement相位差phase-to-phase(line-to-line)voltage相（线）电压phaseinsulation相间绝缘phasesequence相序Phasemodulation(Pm)相位调制phasereversal反相pilotexciter副励磁机plugging反向制动polarity极性pole-changingmotor变极电动机polecore磁极铁心polecoil磁极线圈polepitch极距poleshoe极靴poleendplate磁极端板polyphaserectifier多相整流器polyphaserectifier 多相整流器Polyphase多相(的)potentialtransformer电压互感器poweramplifier功率放大器powerfrequency工频propulsionmotor推进电机pureinductance纯电感purecapacitance纯电容pureresistance纯电阻punching冲片pump泵push-throughwinding插入绕组quadrature-axiscomponentofvoltage电压交轴分量quadrature-axistransienttimeconstant交轴瞬态时间常数quadrature-axiscomponent交轴分量quadrature-axistransientreactance交轴瞬态电抗quadrature-axissynchronousreactance交轴同步电抗r.m.svalues=rootmeansquarevalues均方根值radius半径radialmagneticattractionforce径向磁拉力radialairgap径向气隙random-wound散绕reactance电抗reactivecomponent无功分量reactiveinrespectto相对….呈感性reactivepower无功功率rectifier整流器reluctance磁阻referenceV oltage基准电压reluctance磁阻residualmagnetism剩磁resistance电阻resistivity电阻率reactance电抗retardingtorque制动转矩rheostat变阻器rotatingcommutator旋转（整流子）换向器rotatingmagneticfield旋转磁场rotor转子rotor(stator)winding转子（定子绕组）rotorcore转子铁芯rotorresistance转子电阻rotoryoke转子磁轭rotorlamination转子叠片rotorinter-bar转子漏阻抗roughadjustment粗调salientpoles凸极saturation饱和saturationcurve 饱和曲线saturationeffect饱和效应saturationfactor饱和系数selfexcited自励self-inductor自感semi-enclosedmortor半封闭电动机separatelyexcited他励的series串联seriesexcited串励series-paralledcircuit串并联电路shaft轴shaft-less无轴承的short-circuitingring短路环short-pitching短距shuntdisplacementcurrent旁路位移电流shunt并励，分路器shuntexcitedgenerator并励发电机shuntfield并励磁场silliconsteelplate 硅钢片simplexwavewinding单波绕组simplexlapwinding单叠绕组singleandtwo-layerwinding单双层绕组single-phasing单相运行singlesquirrelcagewinding单鼠笼绕组single-doublelayerwinding单双层混合绕组sinusoidal–densitywave正弦磁密度sinusoidaltimefunction正弦时间函数skewedslot斜槽skineffect集肤效应skin-friction表面摩擦系数slip转差率solidstate固体slot槽slotpermeance槽磁导slotcrosssection槽截面slotpitch槽距slotopening 槽口slotopening槽口宽slotwidth槽宽slotleakageconductance槽漏磁导slotleakageinductance 槽漏抗slotfillingfactor槽满率slotwinding槽绕组slotdepth槽深slotwedge,slotseal槽楔slotharmonic 槽谐波slotmodel槽形slotleakageflux槽漏磁speed-torquecharacteristic速度转矩特性speed-torquecurve转速力矩特性曲线squirrelcage鼠笼squirrelcageinductionmotor笼形感应电机stabilizer稳定器stainlesssteelsleeve不锈钢轴套stator定子statorslot定子槽statoryoke定子轭statorwinding定子绕组steppingmotor步进电机，步进马达steppermotor步进电机step-servo-motor步进伺服电机storagebattery蓄电池surfaceresistance表面电阻superconductinggenerators(ScGs)超导发电机symmetricalcomponent对称分量synchronousgenerator同步发电机synchronousreactance同步电抗synchronousreluctancemotor(SRm)同步磁阻电机synchronousspeed同步转速terminalvoltage端电压temperaturerise温升toothfluxdensity齿磁通密度totalfluxlinkage总磁链toothpitch齿距toothroot齿根toothsaturation齿部饱和toothshape齿形toothtipleakagepermeance齿端漏磁导toothtop齿顶transformer变压器transferfunction传递函数transientresponse瞬态响应transversefluxmotors(TFm)横向磁通电机inductionmachine感应式电机horseshoemagnet马蹄形磁铁magneticfield磁场eddycurrent涡流right-handrule右手定则left-handrule左手定则slip转差率inductionmotor感应电动机rotatingmagneticfield旋转磁场winding绕组stator定子rotor转inductionmachine感应式电机horseshoemagnet马蹄形磁铁magneticfield磁场eddycurrent涡流right-handrule右手定则left-handrule左手定则slip转差率inductionmotor感应电动机rotatingmagneticfield旋转磁场winding绕组stator定子rotor转子inducedcurrent感生电流time-phase时间相位excitingvoltage励磁电压solt槽lamination叠片laminatedcore叠片铁芯short-circuitingring短路环squirrelcage鼠笼rotorcore转子铁芯cast-aluminumrotor铸铝转子bronze青铜horsepower马力random-wound散绕insulation绝缘acmotor交流环电动机endring端环alloy合金coilwinding线圈绕组form-wound模绕performancecharacteristic工作特性frequency频率revolutionsperminute 转/分motoring电动机驱动generating发电per-unitvalue标么值breakdowntorque极限转矩breakawayforce起步阻力overhauling检修wind-drivengenerator风动发电机revolutionspersecond转/秒numberofpoles极数speed-torquecurve转速力矩特性曲线plugging反向制动synchronousspeed同步转速percentage百分数locked-rotortorque锁定转子转矩full-loadtorque满载转矩primemover 原动机iushcurrent涌流magnetizingreacance磁化电抗line-to-neutral 线与中性点间的staorwinding定子绕组leakagereactance漏磁电抗no-load空载fullload满载Polyphase多相(的)iron-loss铁损compleximpedance复数阻抗rotorresistance转子电阻leakageflux漏磁通locked-rotor锁定转子choppercircuit斩波电路separatelyexcited他励的compounded复励dcmotor直流电动机demachine直流电机speedregulation速度调节shunt并励series串励armaturecircuit电枢电路opticalfiber光纤interoffice局间的waveguide波导波导管bandwidth 带宽lightemittingdiode发光二极管silica硅石二氧化硅regeneration再生,后反馈放大coaxial共轴的,同轴的high-performance高性能的carrier载波mature成熟的SingleSideBand(SSB)单边带couplingcapacitor结合电容propagate传导传播modulator调制器demodulator解调器linetrap限波器shunt分路器amplitudemodulation(am调幅FrequencyShiftKeying(FSK)移频键控tuner调谐器attenuate衰减incident入射的two-wayconfiguration二线制generatorvoltage发电机电压dcgenerator直流发电机polyphaserectifier 多相整流器boost增压timeconstant时间常数forwardtransferfunction正向传递函数errorsignal误差信号regulator调节器stabilizingtransformer稳定变压器timedelay延时directaxistransienttimeconstant直轴瞬变时间常数transientresponse瞬态响应solidstate固体buck补偿operationalcalculus算符演算gain增益pole 极点feedbacksignal反馈信号dynamicresponse动态响应voltagecontrolsystem电压控制系统mismatch失配errordetector误差检测器excitationsystem励磁系统fieldcurrent励磁电流transistor晶体管high-gain高增益boost-buck升压去磁feedbacksystem 反馈系统reactivepower无功功率feedbackloop反馈回路automaticV oltageregulator(aVR)自动电压调整器referenceV oltage基准电压magneticamplifier磁放大器amplidyne微场扩流发电机self-exciting自励的limiter限幅器manualcontrol手动控制blockdiagram方框图linearzone线性区potentialtransformer电压互感器stabilizationnetwork稳定网络stabilizer稳定器air-gapflux气隙磁通saturationeffect饱和效应saturationcurve饱和曲线fluxlinkage磁链perunitvalue标么值shuntfield并励磁场magneticcircuit磁路load-saturationcurve负载饱和曲线air-gapline气隙磁化线polyphaserectifier多相整流器circuitcomponents电路元件circuitparameters电路参数electricaldevice电气设备electricenergy电能primarycell原生电池energyconverter电能转换器conductor导体heatingappliance电热器direct-current直流timeinvariant时不变的self-inductor自感mutual-inductor互感thedielectric电介质storagebattery蓄电池e.m.f=electromotivefore电动势unidirectionalcurrent单方向性电流circuitdiagram电路图loadcharacteristic负载特性terminalvoltage端电压externalcharacteristic外特性conductance电导volt-amperecharacteristics 伏安特性篇三：电动机介绍我们这里所说的电动机，一般都是指能为车辆行驶提供全部或部分动力来源的电动机。
细胞培养用青霉素-链霉素产品说明书
细胞培养用青霉素-链霉素产品简介：细胞培养用青霉素-链霉素(Penicillin-Streptomycin for Cell Culture)为粉剂，是最常用的细胞培养用抗生素(即通常所谓的双抗)。
在细胞培养液中推荐的青霉素的工作浓度为100U/ml ，链霉素的工作浓度为0.1mg/ml 。
一个包装的细胞培养用青霉素-链霉素可以配制80L 细胞培养液。
保存条件：室温保存。
4ºC 保存可以使用更长时间。
注意事项：开瓶后需防止受潮。
本产品仅限于专业人员的科学研究用，不得用于临床诊断或治疗，不得用于食品或药品，不得存放于普通住宅内。
为了您的安全和健康，请穿实验服并戴一次性手套操作。
使用说明：细胞培养用青霉素-链霉素可以参考如下两种方法之一使用：1. 配制细胞培养液时加入细胞培养用青霉素-链霉素，然后再过滤除菌：配制细胞培养液时按照青霉素的工作浓度为100U/ml ，链霉素的工作浓度为0.1mg/ml 进行配制，配制完成后过滤除菌即可使用。
2. 配制青霉素-链霉素溶液(100X)母液，然后再添加到细胞培养液中：按照青霉素的含量为10KU/ml ，链霉素的含量为10mg/ml ，配制青霉素-链霉素溶液(100X)母液。
过滤除菌后即可按照100倍稀释加入到细胞培养液中使用。
配制的母液可以-20ºC 冻存。
使用本产品的文献：1. Wang PH, Gu ZH, Wan DH, Zhang MY , Weng SP, Yu XQ, He JG. The shrimp NF-κB pathway is activated by white spot syndrome virus (WSSV) 449 to facilitate the expression of WSSV069 (ie1), WSSV303 and WSSV371.PLoS One. 2011;6(9):e24773.2. Xia M, Zhu Y . Signaling pathways of ATP-induced PGE2 release inspinal cord astrocytes are EGFR transactivation-dependent. Glia. 2011 Apr;59(4):664-74. 3. He YH, Song Y , Liao XL, Wang L, Li G, A lima, Li Y , Sun CH. Thecalcium-sensing receptor affects fat accumulation via effects on antilipolytic pathways in adipose tissue of rats fed low-calcium diets. J N utr. 2011 Nov;141(11):1938-46. 4. Liu XY , Wei W, Wang CL, Yue H, Ma D, Zhu C, Ma GH, Du YGApoferritin-camouflaged Pt nanoparticles: surface effects on cellular uptake and cytotoxicity. J. Mater. Chem., 2011,21, 7105-7110. 5. Wang MN, Liu XY , Cao CB, Shi C Synthesis of band-gap tunable Cu –In –S ternary nanocrystals in aqueous solution RSC Adv. 2012 Feb; 7:2666-70. 6. 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Review超表面相位调控原理及应用Principlesandapplicationsof
在保留了传统超构材料独特电磁特性的基础上，兼具 厚度薄、易加工等优势，在轻量化平面成像、电磁吸 收和虚拟赋形、大视场全息等诸多领域具有广泛的应 用潜力。基于广义折反射定律设计的超构表面器件被 认为是继第一代折反射光学元件和第二代衍射元件之 后的第三代新型光学器件
[20,25]
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256
DOI: 10.3969/j.issn.1003-501X.2017.03.001
1 引
言
光学功能元件大多通过构建曲面面形来实现，其器件 和系统的体积重量通常较大。二十世纪末出现了基于 衍射理论的二元光学[1-2]。二元光学元件利用微电子加 工工艺制备， 在一定程度上实现了光学器件的平面化， 减小了器件体积和重量；并且其与传统折射光学元件 互补的色散特性，在包括色差补偿、球差校正等多种 光学系统中具有巨大的应用前景。但二元光学器件受 材料折射率等因素限制，其厚度仍大于响应波长，且
[24]
其中：k0 是光在自由空间中的波矢，εm 和 εd 分别是金 属和狭缝中介质的介电常数，w 是狭缝的宽度，ksp 为 表面等离子体传播常数。由式(2)可以得到表面等离子 体的传播常数 ksp 和狭缝宽度 w 有直接的关系，因而 可利用狭缝宽度来调制 ksp 的值， 进而控制其局域的光 学相位。将不同宽度的金属狭缝在界面处排列可得到 特定的相位梯度，从而改写传统的斯涅耳定律[20,27]。 基于介质等效折射率理论的超构表面则是利用两 种或多种介质(通常有一种是高折射率介质)在单元结 构内的比例差，实现结构对电磁折射的调制[28-31]。
2.2 传输相位型超构表面器件与应用 平面光学器件是超构表面最有前景的应用之一， 是光子集成和光子芯片发展的关键。利用 MIM 波导 中表面等离子体(SP)模式传播常数随狭缝宽度的变化 规律，可以实现 0~2π 范围内任意梯度的相位变化。 由于 SP 模式的等效折射率理论上可为无限大， 其等效 波长极短， 因此器件厚度可远小于波长。 基于 SP 色散
SAS-3
Matysik TeilElectronic NosesThe sensing layer is a porous thick film of polycrystalline SnO2. In normal ambient air, oxygen and water vapor-related species are adsorbed at the surface of the SnO2 grains.For reducing gases such as CO or H2, a reaction takes place with the pre-adsorbed oxygen and water vapor-related species which decreases the resistance of the sensor. For oxidizing gases such as NO2 and O3, the resistance increases.The magnitude of the changes depends on the microstructure and composition/doping of the base material, on the morphology and geometrical characteristics of the sensing layer and substrate, as well as on the temperature at which the sensing takes place. Alterations of these parameters allow for the tuning of the sensitivity towards different gases or classes of gases.The changes in composition of the ambient atmosphere will determine changes in resistance of the sensing layers.surface of a material exhibiting elasticity, with amplitude that typically decays exponentially with depth into the substrate. => A type of mechanical wave motion Surface acoustic wave sensors are a class of microelectromechanical systems (MEMS) which rely on the modulation of surface acoustic waves to sense a physical phenomenon. The sensor transducers an input electrical signal into a mechanical wave that can be easily influenced by physical phenomena. The device then transducers this wave back into an electrical signal. Changes in amplitude, phase, frequency, or time-delay between the input and output electrical signals can be used to measure the presence of the desired phenomenon.The operation of the SAW device is based on acoustic wave propagation near the surface of a piezoelectric solid.The accumulation of mass on the surface of an acoustic wave sensor will affect the surface acoustic wave as it travels across the delay line.The wave velocity will decrease with added mass. This change can be measured by a change in time-delay or phase-shift between input and output signals. Signal attenuation could be measured as well, as the coupling with the additional surface mass will reduce the wave energy. In the case of mass-sensing, as the change in the signal will always be due to an increase in mass from a reference signal of zero additional mass, signal attenuation can be effectively used.are organic polymers that conductelectricity. Such compounds may have metallic conductivity or can be semiconductors. The biggest advantage of conductive polymers is their processability, mainly by dispersion.Principal components analysis (PCA) is one of a family of techniques fortaking high-dimensional data, and using the dependencies between the variables to represent it in a more tractable, lower-dimensional form, without losing too much information. PCA is one of the simplest and most robust ways of doing such dimensionality reduction.In computer science and related fields, artificial neural networks are computational models inspired by animal central nervous systems (in particular the brain) that are capable of machine learning and pattern recognition. They are usually presented as systems of interconnected "neurons" that can compute values from inputs by feeding information through the network.Potentiometric SensorsPotentiometric sensors use the effect of the concentration on the equilibrium of redox reactions occurring at the electrode-electrolyte interface of an electrochemical sensor. PH glass membrane electrodes: A glass electrode is a type of ion-selective electrode made of a doped glass membrane that is sensitive to a specific ion. The electric potential of the electrode system in solution is sensitive to changes in the content of a certain type of ions, which is reflected in the dependence of the electromotive force (EMF) of galvanic element concentrations of these ions.In a potentiometric sensor, two half-cell reactions take place at each electrode. Only one of the reactions should involve sensing the species of interest. The other should be a well understood reversible and non-interfering reaction.The Nernst equation gives the potential of each half cell.Because of the ion-exchange nature of the glass membrane, it is possible for some other ions to concurrently interact with ion-exchange centers of the glass and to distort the linear dependence of the measured electrode potential on pH or other electrode function. For example, some silicate pNa electrodes can be changed to pAg function by soaking in a silver salt solution.Interference effects are commonly described the semiempirical Nicolsky-Eisenman equation , an extension to the Nernst equation.two distinct types of electrodes as one unit => combination of the glass electrode and the reference electrode into one body.)(log 00R e C C nF RT E E +=The measuring part of the electrode, the glass bulb on the bottom, is coated both inside and out with a ~10 nm layer of a hydrated gel. These two layers are separated by a layer of dry glass. The silica glass structure is shaped in such a way that it allows Na+ ions some mobility. The Na+ in the hydrated gel diffuse out of the glass and into solution while H+ from solution can diffuse into the hydrated gel. It is the hydrated gel, which makes the pH electrode an ion-selective electrode.H+ does not cross through the glass membrane of the pH electrode, it is the Na+ which crosses and allows for a change in free energy. When an ion diffuses from a region of activity to another region of activity, there is a free energy change and this is what the pH meter actually measures.Glass electrode || Reference Solution || Test Solution || Glass electrodeAg(s) | AgCl(s) | KCl(aq) || 1×10-7M H+ solution || glass membrane || Test Solution || ceramic junction || KCl(aq) | AgCl(s) | Ag(s)A total ionic strength adjustment buffer (TISAB) is a buffer solution which increases the ionic strength of a solution to a relatively high level. This is important for potentiometric measurements, including ion selective electrodes, because they measure the activity of the analyte rather than its concentration. TISAB essentially masks most chemical interferences in the analyte solution and hence increases the accuracy of the reading.An ion-selective electrode (ISE), is a transducer (or sensor) that converts theactivity of a specific ion dissolved in a solution into an electrical potential, which can be measured by a voltmeter or pH meter. The voltage is theoretically dependent on the logarithm of the ionic activity, according to the Nernst equation. The sensing part of the electrode is usually made as an ion-specific membrane, along with a reference electrode.the gate electrode. A voltage between substrate and oxide surfaces arises due toan ions sheath..Using a series of calibrating solutions the response curve or calibration curve of an ion-selective electrode can be measured and plotted as the signal (electromotive force) versus the activity of the analyte. The linear range of the calibration curve is usually applied to determine the activity of the target ion in any unknown solution.concentration of the interfering species is Cb = const., concentration of the analyte species is Ca, which can vary in the analytic function y = S log Ca where S is simply the slope or responsiveness of the instrumentif you put tangents through the functions containing Cb and Ca, the tangents will intersect at the concentration CkCk/Cb = Kabwhich results arithmeticallyso you can determine Kab by finding the intersection between the two tangents graphically and reading out the corresponding conc., then dividing by the known interferent conc.Amperometric SensorsScreen-Printing: Screen printing is a printing technique that uses a woven mesh to support an ink-blockingstencil to receive a desired image. The attached stencil forms open areas of mesh that transfer ink or other printable materials which can be pressed through the mesh as a sharp-edged image onto a substrate.BiosensorAmperometric biosensors function by the production of a current when a potential is applied between two electrodes.The simplest amperometric biosensorof a platinum cathode at which oxygen is reduced and a silver/silver chloride reference electrode. When a potential of -0.6 V, relative to the Ag/AgCl electrode is applied to the platinum cathode, a current proportional to the oxygen concentration is produced. Normally both electrodes are bathed in a solution of saturated KCl and separated from the bulk solution by an oxygen-permeable plastic membrane (e.g. Teflon).A typical application is the determination of glucose concentrations by the use of an immobilised glucose oxidase membrane. The reaction results in a reduction of the oxygen concentration as it diffuses through the biocatalytic membrane to the cathode, this being detected by a reduction in the current between the electrodes.The major problem with these biosensors is their dependence on the dissolved oxygen concentration. This may be overcome by the use of 'mediators' which transfer the electrons directly to the electrode bypassing the reduction of the oxygen co-substrate. In order to be generally applicable these mediators must possess a number of useful properties.1. They must react rapidly with the reduced form of the enzyme.2. They must be sufficiently soluble, in both the oxidised and reduced forms, to be able to rapidly diffuse between the active site of the enzyme and the electrode surface.3. This solubility should, however, not be so great as to cause significant loss of the mediator from the biosensor's microenvironment to the bulk of the solution. However soluble, the mediator should generally be non-toxic.4. The overpotential for the regeneration of the oxidised mediator, at the electrode, should be low and independent of pH.5. The reduced form of the mediator should not readily react with oxygen.The ferrocenes represent a commonly used family of mediators.(a) First generation electrode utilising the H2O2 produced by the reaction.(E0 = +0.68 V).(b) Second generation electrode utilising a mediator (ferrocene) to transfer the electrons, produced by the reaction, to the electrode. (E0 = +0.19 V).(c) Third generation electrode directly utilising the electrons produced by the reaction. (E0 = +0.10 V).All electrode potentials (E0) are relative to the Cl-/AgCl,Ag0 electrode.Immobilization of enzyme1.Adsorption of enzymes onto insoluble supports is a very simple method of wide applicability and capable of high enzyme loading (about one gram per gram of matrix). Simply mixing the enzyme with a suitable adsorbent, under appropriate conditions of pH and ionic strength, followed, after a sufficient incubation period, by washing off loosely bound and unbound enzyme will produce the immobilised enzyme in a directly usable form. The driving force causing this binding is usually due to a combination of hydrophobic effects and the formation of several salt links per enzyme molecule. Examples of suitable adsorbents are ion-exchange matrices, porous carbon, clays, hydrous metal oxides, glasses and polymeric aromatic resins.2. Immobilisation of enzymes by their covalent coupling to insoluble matrices is an extensively researched technique. Only small amounts of enzymes may be immobilised by this method (about 0.02 gram per gram of matrix). The strength of binding is very strong, however, and very little leakage of enzyme from the support occurs. Lysine residues are found to be the most generally useful groups for covalentbonding of enzymes to insoluble supports due to their widespread surface exposure and high reactivity, especially in slightly alkaline solutions. The most commonly used method for immobilising enzymes on the research scale (i.e. using less than a gram of enzyme) involves Sepharose, activated by cyanogen bromide. Sepharose is highly hydrophilic and generally inert to microbiological attack, it reacts with primary amino groups (i.e. mainly lysine residues) on the enzyme under mildly basic conditions (pH 9 - 11.5)3.Entrapment of enzymes within gels or fibres is a convenient method for use in processes involving low molecular weight substrates and products. Example: the enzymes' surface lysine residues may be derivatised by reaction with acryloyl chloride (CH2=CH-CO-Cl) to give the acryloyl amides. This product may then be copolymerised and cross-linked with acrylamide (CH2=CH-CO-NH2) and bisacrylamide (H2N-CO-CH=CH-CH=CH-CO-NH2) to form a gel.4. Membrane confinement of enzymes may be achieved by a number of quite different methods, all of which depend for their utility on the semipermeable nature of the membrane. Enzymes encapsulate within small membrane-bound droplets or liposomes.。
原子力显微镜的新测试方法——HybriD-Mode
HybriD™Mode Atomic Force Microscopy(AFM) from NT-MDT-An Interview with Sergei Magonov Interview by Will SoutterAZoNano talks to Sergei Magonov about NT-MDT's new HybriD™AFM Mode,which combines the best aspects of contact and oscillatory modes,opening up new applications of AFM technology.WS:NT-MDT has just announced a new AFM mode–HybriD™Mode,or HD-AFM™Mode.Can you give us an overview of how this new mode works,and what it offers?SM:HD-AFM™Mode synergistically combines the best attributes of contact and oscillatory AFM modes.In contact mode,the probe deflection is directly related to the applied force,but lateral forces may induce tip and sample damage. The resonant oscillatory modes(amplitude modulation,tapping mode,intermittent contact,etc.)greatly reduce the lateral tip-sample forces;however,the measured probe amplitude is related to the tip-sample forces in a very complicated way that precludes quantitative nanomechanical measurements.A key advantage of the new HD-AFM™Mode,in which the oscillatory intermittent tip-sample contact happens at frequencies lower than the scanner and probe resonances,is that the probe deflection is directly related to the tip-sample forces.Our proprietary fast acquisition and processing of deflection curves in the HD-AFM™Mode helps extract a whole bank of the force data related to the mechanical(adhesion,stiffness,elastic modulus,etc.)and electromagnetic properties(surface potential,dielectric response,magnetic domains)involved in nanoscale tip-sample interactions.These properties are mapped simultaneously and independently with the imaging of sample topography.Examples of the HD-AFM™Mode applications that demonstrate current capabilities are available as a webinar and application note.HybriD AFM™controller for NT-MDT AFM platformsWS:What are the main benefits of HD-AFM™compared to the range of AFM modes already available to users?SM:The tip-sample forces in HD-AFM™Mode differ from those in other contact and oscillatory modes by magnitude and duration, therefore,the researchers can expect exciting observations of new effects with improvements in the visualization of morphology and nanostructure for complex materials.HD-AFM™Mode opens a pathway towards real-time quantitative studies of local nanomechanical properties on a broader range of materials.Particularly,we believe that this mode can facilitate studies of time-dependent mechanical properties such as viscoelasticity.WS:What are the main application areas that HD-AFM™is designed for?SM:Actually,the practical results obtained with the HD-AFM™Mode have definitely revealed a wider range of applications than other modes can offer.The development of the oscillatory non-resonant mode opens the compositional mapping and quantitative nanomechanical studies of materials with elastic modulus larger than10GPa,which are typically beyond the range of applications using the oscillatory resonant modes.Imaging biological and material samples under liquid also benefits from the use of HD-AFM™Mode as the non-resonant method eliminates the forest of resonant peaks during experimental set-up thus significantly improving the ease of use and speed to results.Hybrid Mode height image(left)and adhesion and stiffness maps,which were obtained in Hybrid mode study of polymerfilm of polystyrene/polybutadiene blend.This very challenging sample was chosen because of the large mismatch inmodulus between the two components and the added complexity of the strong viscoelastic response of Polybutadiene.Although there are currently no adaptive models to accurately calculate both the elastic response of Polystyrene and the viscoelastic response of Polybutadiene when collect in an image map,Hybrid mode does reveal morphology and variations of local properties of this immiscible composition down to tens of nanometers dimensions.WS:How did you come up with the idea to develop this new mode?SM:One of our goals is to continuously improve and provide new capabilities to benefit research in the scientific community,and we believed that could impact key areas of compositional mapping and quantitative nanomechanical properties.From an instrumentation perspective,part of the new HD-AFM™Mode arose from a practical implementation based on the novel technology developments of our electronic controllers,which recently brought substantial benefits to our microscopes by reducing the noise of the probe amplitude detection(down to25fm/sqrtHz)and through fast data acquisition and processing.This technology formed a solid platform for expansion of the AFM functions and the introduction of the HD-AFM™Mode.WS:How will HD-AFM™set NT-MDT’s instruments apart from your competition?SM:Our mission is to provide customers with a comprehensive suite of scanning probe microscopy capabilities to help make their research leading-edge and most efficient.Regarding the HD-AFM™Mode itself,we believe its operation is superior to othernon-resonant oscillatory modes available in the market and we are currently proving that with comparative studies on a challenging set of samples.Moreover,with the addition of HD-AFM™,the NT-MDT microscopes are now equipped with the broadest range of capabilities on the market.Our instruments enable researchers to conduct advanced single-pass electric studies in amplitude modulation mode,which provides simultaneous measurement of topography,surface potential,and dielectric response.We are also working towards quantitative electrical property analysis based on such data.The chemical characterization of materials is achieved by the combination of AFM with confocal Raman scattering in our NT-MDT Spectra microscope.The single-pass electric measurements and HD-AFM™Mode studies are also available in this instrument.Brush macromolecules on mica substrates are visualized in the height images obtained in amplitude modulation andHybrid mode,whereas only in the latter case side chains are clearly resolved.Sample of brush macromolecules–courtesy of Prof.S.Sheiko(UNC).WS:Which AFMs in the NT-MDT range will the new mode be available for?What will the upgrade process be like for users?SM:The HD-AFM™Mode is available on all four of our major instrument platforms;NTEGRA,NEXT,Spectra,and LIFE.The implementation of HD-AFM™Mode is directly related to a novel fast data acquisition module that can be added for recent electroniccontrollers.Contact your local NT-MDT representative for upgrade details specific to your microscope.WS:Are there plans to extend the new capabilities to the other instruments in your product range?SM:Such plans not only exist,they are already being implemented!WS:Can you give us any clues about what other developments to expect from NT-MDT in the near future?SM:Generally speaking,the practical realization of true quantitative nanomechanical and quantitative electrical property measurements at the nanoscale,in broad frequency and temperature ranges,is on our path.Efforts in this direction could be easily coupled to the increasing interest of researchers in chemical characterization by combining AFM with spectroscopic methods.Height images obtained in Hybrid Mode of alkane layers of different chain lengths demonstrate the high-resolutioncapability of this technique enabling the ability to resolve the packing of individual chains(inset image)in the image of C390H782lamellae.Sample of C390H782alkane–courtesy of Prof.G.Ungar(Sheffield University).WS:Where can we find more information about HD-AFM™,and NT-MDT AFM products in general?SM:There are application notes and datasheets available on the NT-MDT website.In addition,a recording of our recent webinar with Virgil Elings and Sergei Magonov,New HD-AFM™Mode;Your Path to Controlling Forces for Precise Material Properties is available to view and download.About Sergei MagonovDr.Sergei Magonov received a doctorate in physics and mathematics from the Moscow Institute of Physics and Technology.Sergei has published over200peer-reviewed papers,1book,and15book chapters.He is now CEO of NT-MDT Development,an R&D subsidiary that was established for the development of novel experimental and applications capabilities using NT-MDT microscopes.Date Added:Jul2,2013|Updated:Jul30,2013NT-MDTNT-MDTPost Box158,Building317-AZelenogradMoscow,124482Russian FederationPH:7(495)5350305Fax:7(495)9135739Email:spm@ntmdt.ruVisit NT-MDT WebsitePrimary ActivityComponent SupplierCompany BackgroundNT-MDT Co.was established in1991with the purpose to apply all accumulated experience and knowledge in the field ofnanotechnology to supply researchers with the instruments suitable to solve any possible task laying in nanometer scale dimensions.The company NT-MDT was founded in Zelenograd-the center of Russian Microelectronics.The products development are based on the combination of the MEMS technology,power of modern software,use of high-end microelectronic components and precision mechanical parts.As a commercial enterprise NT-MDT Co.exists from1993.Now the NT-MDT team develops for you the complete line of SPMs which cover most of scientific and industrial applications.The first NT-MDT device was designed in1990and was called STM-MDT-1-90(Scanning Tunneling Microscope).Till now,this firstmicroscope duly runs in the Institute of Cristallography RAS(Russia).STM-4was developed in1993.The device model Solver appeared in1995starting the Solver product line.The same year the model Solver P47was made.1998was marked by Solver LS, Stand Alone SMENA systems.Special SPM for biological applications called Solver BIO supplemented NT-MDT product line in1999.The next year we developed X,Y Scanning stage for closed-loop operation.Now we can offer you the whole SPM line including AFMs,STMs,SNOMs for almost all possible applications and we continue development of new powerful tools for you..We also supply a wide range of silicon probes and calibration gratings production, design and development that allows us to understand and meet your requirements better.550employees include Ph.D.scientists,many leaders in their field.More than600installations in39countries,more then15year in the SPM market,worldwide distribution of our devices.Our clients are Universities and colleges,laboratories,government and private industrial companies,research centers and small scientific companies on the nanotechnology fieldNT-MDT Co.has two mottos-"Fairness,Intellect,Quality"and"What seems the future to others is the present for us".The bases to successful development are:the best"brains",the best components,high technologies,up-to-date marketing and control.In summary we have:powerful software,best electronics,best mechanics,micro robotics and sales in the world market.Territories ServicedWorldwide。
表面织构对椭球体－平面接触热弹流润滑的影响
表面织构对椭球体－平面接触热弹流润滑的影响卢宪玖;王优强;王迪迪【摘要】基于椭球体－平面几何和数学模型，分别采用多重网格法和多重网格积分法求解光滑及带有表面织构（正方体微凹坑、圆柱形凹坑）椭球体的压力、膜厚分布及其表面的温度分布，分析不同滑滚比（1.0～2.0）下2种不同表面织构的最小膜厚和最高温度。
结果表明：温度对表面织构的弹流润滑性能影响较大，不可忽略；2种织构表面的油膜厚度较光滑表面增大，且在圆柱体表面织构的底面半径跟正方体表面织构边长相同时，前者表面所形成的油膜厚度更大，整体温度更小；随着滑滚比的增大，2种织构表面的最小膜厚减小，最高温度增大，其中圆柱体表面织构具有更大的最小膜厚，更低的最高温度。
%Based on the geometric and mathematical model of ellipsoid-plane contact,the multi-grid,multilevel multi-in-tegration method and sequential column sweeping technique were respectively adopted to calculate the pressure,film and temperature distribution of the smooth surface and the surfaces with textures of cubic and cylindrical micro pit.The mini-mum film thickness and maximum temperature was analyzed for two kinds of texture surfaces at different slide-roll ratios. Results show that the temperature has greater influence on the elastohydrodynamic lubrication performance.The film thick-ness of two kinds of texture surfaces is thicker than that of smooth surface,when the cylinder radius and cubic side length is equal,the surface with cylindrical texture has larger film thickness and lower whole temperature.Along with the increas-ing of slide-roll ratios,the minimum film thickness of two kinds of texture surfaces is decreased and themaximum tempera-ture is increased,and the surface with cylindrical texture has larger minimum film thickness and lower maximum tempera-ture.【期刊名称】《润滑与密封》【年(卷),期】2014(000)012【总页数】5页(P75-79)【关键词】圆柱体表面织构;正方体表面织构;滑滚比;热弹流润滑【作者】卢宪玖;王优强;王迪迪【作者单位】青岛理工大学机械工程学院山东青岛266033;青岛理工大学机械工程学院山东青岛266033;青岛理工大学机械工程学院山东青岛266033【正文语种】中文【中图分类】TH117随着机械工业的不断发展，加工技术日趋完善，表面织构技术已广泛应用于计算机硬盘、轴承以及发动机系统中。
肿瘤转移英文版
Tumor cells detach from the primary tuber and enter the bloodstream or lymphatic system
Linear metastasis
Cancer cells spread through the linear system to linear nodes and other issues
Site specific metathesis: Some tutor cells have the ability to preferentially identify specific organizations or issues, often related to their issues of origin
English version of tumor metastasis
目录
contents
Overview of Tumor MetastasisThe mechanism of tuber metastasisDiagnosis and monitoring of tuber metastasisTreatment of tuber metastasisPrevention and control of tuber metastasis
The mechanism of tuber metastasisBiblioteka CATALOGUE02
Self renew
Tumor cells have the ability to replicate and form new Tumor cells
Tumor cells can invade surrounding issues and migrate to other parts of the body
TiAlSiN_涂层力学性能改善措施的研究现状及进展
表面技术第53卷第8期TiAlSiN涂层力学性能改善措施的研究现状及进展周琼，王涛，黄彪*，张而耕，陈强，梁丹丹 （上海应用技术大学 上海物理气相沉积（PVD）超硬涂层及装备工程技术研究中心，上海 201418）摘要：TiAlSiN涂层具有耐温性好、化学惰性高等优异性能，其作为防护层被广泛应用于摩擦零部件、机械加工工具上。
但TiAlSiN涂层内应力过大导致的力学性能不足，限制了其在严苛工况下的进一步应用。
总结了目前改善TiAlSiN涂层力学性能的主要措施：涂层微观结构优化、膜层结构设计以及热处理工艺。
对改善涂层力学性能所涉及的细晶强化、共格效应、固溶强化以及模量差理论等机理进行了全面的描述，并详细地对比分析了上述理论之间的内在联系与差异。
系统地讨论了纳米多层和梯度复合膜层结构对涂层力学性能的影响规律，主要从调制结构以及成分调整2个角度对膜层结构变化进行了分析，有利于指导具有良好力学性能的膜层结构的设计。
此外，分别阐述了退火温度、时间以及气氛环境对TiAlSiN涂层力学性能的影响规律，分析了退火条件对涂层微观结构的影响以及微观结构与力学性能之间的关系。
在此基础上，提出了未来可以从基础理论和改善措施之间的协同作用角度，对TiAlSiN涂层力学性能的改善展开进一步研究。
关键词：TiAlSiN；性能改善；力学性能；微观结构；膜层结构；热处理中图分类号：TG174.4 文献标志码：A 文章编号：1001-3660(2024)08-0040-12DOI：10.16490/ki.issn.1001-3660.2024.08.004Research Status and Progress of Improving MechanicalProperties of TiAlSiN CoatingsZHOU Qiong, WANG Tao, HUANG Biao*, ZHANG Ergeng, CHEN Qiang, LIANG Dandan(Shanghai Engineering Research Center of Physical Vapor Deposition (PVD) Superhard Coating and Equipment,Shanghai Institute of Technology, Shanghai 201418, China)ABSTRACT: TiAlSiN coatings have excellent high temperature resistance and chemical inertness, and they have been widely used on friction work pieces and cutting tools. However, their high internal stress limits their further application in industries under harshworking conditions. This paper focuses on the main techniques employed to improve the mechanical properties of TiAlSiN coatings, including microstructure optimization, micro-structure design and treatment. The coating hardness is predominantly influenced by microstructure, which can be tailored through various processing methods such as deposition method optimization, and modulation of the deposition process parameters including nitrogen flow rate, substrate bias, target quantity, and power duration. In addition, doping new elements and changing the original element content of TiAlSiN coatings also affect the hardness of the coatings. In this work, the mechanisms involved in improving the mechanical properties of the收稿日期：2023-05-08；修订日期：2023-07-29Received：2023-05-08；Revised：2023-07-29基金项目：国家自然科学基金资助项目（51971148）；上海市自然科学基金资助项目（20ZR1455700）Fund：The National Natural Science Foundation of China (51971148); Shanghai Natural Science Foundation (20ZR1455700)引文格式：周琼, 王涛, 黄彪, 等. TiAlSiN涂层力学性能改善措施的研究现状及进展[J]. 表面技术, 2024, 53(8): 40-51.ZHOU Qiong, WANG Tao, HUANG Biao, et al. Research Status and Progress of Improving Mechanical Properties of TiAlSiN Coatings[J]. Surface Technology, 2024, 53(8): 40-51.*通信作者（Corresponding author）第53卷第8期周琼，等：TiAlSiN涂层力学性能改善措施的研究现状及进展·41·coatings, such as fine grain strengthening, solid solution strengthening and modulus difference theory, were compared and analyzed. The refinement of grain size resulting from fine-crystal strengthening reduced the crack propagation, while solid-solution strengthening was achieved by introducing foreign atoms into a compound to form a solid solution, thereby increasing the hardness of the TiAlSiN coatings. The coherent effect and modulus difference theory promoted the enhancement of TiAlSiN coating hardness through interface structure optimization. Both mechanisms induced interfacial stresses that prevented dislocation generation. The internal relations and differences between the above theories were compared and analyzed in detail. The effect of nano-multilayer and gradient composite layers on the mechanical properties of the coatings was systematically discussed. Modulation structure and composition adjustment were the two main factors that affected the variation of micro-structure. Currently, research on the strengthening mechanisms of nano-layered coatings and gradient-structured coatings is not comprehensive. Even small structural alterations to these coatings can cause various influence mechanisms that alter their mechanical properties. For instance, changing the modulation period significantly impacts the mechanical behavior of TiAlSiN coatings by means of coherent strain and the modulus difference theory. It is helpful to guide the design of membrane structure with good mechanical properties. In addition, heat treatment has the most significant effect on the properties of TiAlSiN coatings. So the influence of annealing temperature, annealing time, and atmosphere on the mechanical properties of TiAlSiN coatings was summarized. The effect of annealing conditions on the microstructure of the coatings and the relationship between the microstructure and mechanical properties were analyzed. In addition to experimental research, basic theoretical research was also be conducted by starting from first principles to identify the specific relationships and influence mechanisms between microstructure and mechanical properties of coatings. Annealing had three main effects on the mechanical properties of TiAlSiN coatings: grain coarsening, phase transformation, and surface oxide formation. Annealing resulted in grain coarsening, which improved the toughness of the coatings. The mechanical properties of TiAlSiN coatings were affected by the phase structure when phase transitions occurred during annealing. Additionally, the significance of the synergistic effect of improving measures on the mechanical properties of TiAlSiN coatings was emphasized. Finally, it was suggested to conduct deep research in future on improving mechanical properties of TiAlSiN coatings from basic theory and cooperation effect of various improvement actions.KEY WORDS: TiAlSiN; property improvement; mechanical property; microstructure; film structure; heat treatment现代刀具材料主要有高速钢、硬质合金、金属陶瓷等，随着切削加工技术的不断提高，其力学性能已经逐渐不能满足工业上的要求，而提升涂层的力学性能可以弥补刀具材质上的不足[1-5]。
DIN标准中文版
铸件 技术交付状态 第3部分 铸铁件的附加 要求
DIN 2500-1966 DIN 3017.1-1998 DIN 3017.2-2002 DIN 3017.3-2002 DIN 3017.4-1998 DIN 3141-1960 DIN 6796-1987 DIN 6912-2002
法兰 一般说明 概况 软管卡圈 第1部分 涡轮传动软管卡圈 A型 软管夹件 第2部分 带夹紧凸缘的夹件 软管夹件 第3部分 螺栓卡圈 软管夹件 第4部分 技术交货条件 图纸上的表面符号 表面粗糙的分类 螺钉连接用弹簧垫圈 内六角中心低圆柱头螺钉
lighe pipe clips with pipe-tightening single ended for rail vehicles founding technical conditions of delivery part 1 general founding technical conditions of delivery part 3 additional requirements for iron castings
DIN 6935-1975
扁轧钢产品的冷弯
DIN 7080-2005
DIN 8140.1-1999 DIN 8140.2-2005
低温范围内无限制的硼硅玻璃制抗压式圆形 视孔玻璃板
木制指形接头 第1部分 承载结构用软木的指 形接头 ISO米制螺纹用钢丝制螺纹嵌镶件 螺纹公差
DIN 8140.3-1993
DIN 323.1-1974 DIN 323.2-1974
标准值和标准系列 主值 精确值 近似值 标准值和标准系列 引言
DIN 935.1-2000
六角开槽螺母和槽形螺母 第1部分 米制粗牙 和细牙螺纹 产品等级A和B
纳米生物润滑剂微量润滑磨削性能研究进展
第52卷第12期表面技术2023年12月SURFACE TECHNOLOGY·1·专题——多场赋能清洁切削/磨削纳米生物润滑剂微量润滑磨削性能研究进展宋宇翔1，许芝令2，李长河1*，周宗明3，刘波4，张彦彬5，Yusuf Suleiman Dambatta1,6，王大中7（1.青岛理工大学 机械与汽车工程学院，山东 青岛 266520；2.青岛海空压力容器有限公司， 山东 青岛 266520；3.汉能（青岛）润滑科技有限公司，山东 青岛 266100；4.四川新航钛科技有限公司，四川 什邡 618400；5.香港理工大学超精密加工技术国家重点实验室，香港 999077；6.艾哈迈杜·贝洛大学 机械工程学院，扎里亚 810106；7.上海工程技术大学 航空运输学院，上海 200240）摘要：微量润滑是针对浇注式和干磨削技术缺陷的理想替代方案，为了满足高温高压边界条件下磨削区抗磨减摩与强化换热需求，进行了纳米生物润滑剂作为微量润滑的雾化介质探索性研究。
然而，由于纳米生物润滑剂的理化特性与磨削性能之间映射关系尚不清晰，纳米生物润滑剂作为冷却润滑介质在磨削中的应用仍然面临着严峻的挑战。
为解决上述需求，本文基于摩擦学、传热学和工件表面完整性对纳米生物润滑剂的磨削性能进行综合性评估。
首先，从基液和纳米添加相的角度阐述了纳米生物润滑剂的理化特性。
其次，结合纳米生物润滑剂独特的成膜和传热能力，分析了纳米生物润滑剂优异的磨削性能。
结果表明，纳米生物润滑剂优异的传热和极压成膜性能显著改善了磨削区的极端摩擦条件，相比于传统微量润滑，表面粗糙度值（Ra）可降低约10%~22.4%。
进一步地，阐明了多场赋能调控策略下，磨削区纳米生物润滑剂浸润与热传递增效机制。
最后，针对纳米生物润滑剂的工程和科学瓶颈提出了展望，为纳米生物润滑剂的工业应用和科学研究提供理论指导和技术支持。
关键词：磨削；微量润滑；纳米生物润滑剂；多场赋能；表面完整性；理化特性中图分类号：TG580.6 文献标识码：A 文章编号：1001-3660(2023)12-0001-19DOI：10.16490/ki.issn.1001-3660.2023.12.001Research Progress on the Grinding Performance of NanobiolubricantMinimum Quantity LubricationSONG Yu-xiang1, XU Zhi-ling2, LI Chang-he1*, ZHOU Zong-ming3, LIU Bo4,ZHANG Yan-bin5, DAMBATTA Y S1, WANG Da-zhong7收稿日期：2022-11-03；修订日期：2023-05-19Received：2022-11-03；Revised：2023-05-19基金项目：国家自然科学基金（52105457，51975305）；山东省科技型中小企业创新能力提升工程（2021TSGC1368）；青岛市科技成果转化专项园区培育计划（23-1-5-yqpy-17-qy）；泰山学者工程专项经费（tsqn202211179）；山东省青年科技人才托举工程（SDAST2021qt12）；山东省自然科学基金（ZR2023QE057，ZR2022QE028，ZR2021QE116，ZR2020KE027）Fund：The National Natural Science Foundation of China (52105457, 51975305); The Science and Technology SMEs Innovation Capacity Improvement Project of Shandong Province (2021TSGC1368); Qingdao Science and Technology Achievement Transformation Special Park Cultivation Programme (23-1-5-yqpy-17-qy); The Special Fund of Taishan Scholars Project (tsqn202211179); The Youth Talent Promotion Project in Shandong (SDAST2021qt12); The Natural Science Foundation of Shandong Province (ZR2023QE057, ZR2022QE028, ZR2021QE116, ZR2020KE027)引文格式：宋宇翔, 许芝令, 李长河, 等. 纳米生物润滑剂微量润滑磨削性能研究进展[J]. 表面技术, 2023, 52(12): 1-19.SONG Yu-xiang, XU Zhi-ling, LI Chang-he, et al. Research Progress on the Grinding Performance of Nanobiolubricant Minimum Quantity Lubrication[J]. Surface Technology, 2023, 52(12): 1-19.*通信作者（Corresponding author）·2·表面技术 2023年12月(1. School of Mechanical and Automotive Engineering, Qingdao University of Technology, Shandong Qingdao, 266520, China;2. Qingdao Haikong Pressure Vessel Sales Co., Ltd., Shandong Qingdao, 266520, China;3. Hanergy (Qingdao) LubricationTechnology Co. Ltd., Shandong Qingdao, 266100, China; 4. Sichuan New Aviation Ta Technology Co., Ltd., Sichuan Shifang 618400, China; 5. State Key Laboratory of Ultra-precision Machining Technology, Hong Kong Polytechnic University, Hong Kong, China, 999077, China; 6. Mechanical Engineering Department, Ahmadu Bello University, Zaria, 810211, China;7. School of Air Transportation, Shanghai University of Engineering Science, Shanghai, 201620, China)ABSTRACT: The negative impact of traditional mineral oil based grinding fluids on environmental protection, human health and manufacturing costs can hardly meet the development needs of green manufacturing. Minimum quantity lubrication (MQL) atomizes a small amount of biodegradable biolubricants with compressed air to form micro droplets to providing lubrication and anti-wear effects, which is an ideal alternative to flooding and dry grinding technology defects. In order to meet the requirements of anti-wear and friction reduction and enhanced heat transfer in the grinding zone under high temperature and high pressure boundary conditions, nanobiolubricants have been widely investigated as atomised media for minimum quantity lubrication.However, the application of nanobiolubricants as cooling and lubrication media in grinding still faces serious challenges due to the unclear mapping relationship between the physicochemical properties of nanobiolubricants and grinding performance. This is due to the fact that the mechanisms of action of nanoparticles on lubricants is a result of multiple coupling factors.Nanoparticles will not only improve the heat transfer and tribological properties of biological lubricants, but also increase their viscosity. However, the coupling mechanisms between the two factors are often be overlooked. In addition, as a cooling and lubrication medium, the compatibility between nanobiolubricants with different physical and chemical properties and workpiece materials also needs to be further summarized and evaluated. To address these needs, this paper presents a comprehensive assessment of the grinding performance of nanobiolubricants based on tribology, heat transfer and workpiece surface integrity.Firstly, the physicochemical properties of nanobiolubricants were described from the perspectives of base fluids and nano additive phase. And factors which influenced thermophysical properties of nanobiolubricants were analysed. Secondly, the excellent grinding performance of the nanobiolubricants was analysed in relation to their unique film-forming and heat transfer capabilities. Coolingand lubrication mechanism of nanobiolubricants in grinding process was revealed. The results showed that nanobiolubricants can be used as a high-performance cooling lubricant under the trend of reducing the supply of grinding fluids.The excellent heat transfer and extreme pressure film-forming properties of nanobiolubricants significantly improved the extreme friction conditions in the grinding zone, and the surface roughness values (Ra) could be reduced by about 10%-22.4%, grinding temperatures could be reduced by about 13%-36% compared with the traditional minimum quantity lubrication.Furtherly, the multi-field endowment modulation strategy was investigated to elucidate the mechanism of nanobiolubricant infiltration and heat transfer enhancement in the multi-field endowed grinding zone. Multiple fields such as magnetic and ultrasonic fields have improved the wetting performance of nanobiolubricant droplets, effectively avoiding the thermal damage and enabling the replacement of flood lubrication. In the grinding of hard and brittle materials, ultrasonic energy not only enhances the penetration of the grinding fluid through the pumping effect, but also reduces the brittle fracture of the material, and the surface roughness value (Ra) can be reduced by about 10%-15.7% compared with the traditional minimum quantity lubrication. Finally, an outlook for engineering and scientific bottleneck of nanobiolubricants was presented to provide theoretical guidance and technical support for the industrial application and scientific research of nanobiolubricants.KEY WORDS: grinding; minimum quantity lubrication; nanobiolubricants; multi-field empowerment; surface integrit;physicochemical property磨削作为机械加工中的一项关键技术，是保证表面完整性所必需的精密加工方法[1]。
微观表面形貌对角接触球轴承热弹流润滑的影响
微观表面形貌对角接触球轴承热弹流润滑的影响卢宪玖;王优强;律辉;刘昺丽【摘要】建立角接触球轴承的热弹流润滑数学模型,通过求解考虑热效应的Reynolds方程,对润滑条件下的角接触球轴承在考虑表面粗糙度时的弹流润滑问题进行数值模拟.在缺乏实测数据的情况下,采用了涉及轴承滚道和滚球体面上的余弦粗糙波数学模型,分析考虑热效应的角接触球轴承的表面粗糙度对压力和膜厚的影响.结果表明:考虑x和y方向的粗糙度函数可以更好地模拟轴承滚道及滚球体表面的形貌特征,由此计算出的压力和油膜分布更贴近工程实际;考虑两方向的粗糙度后,压力和油膜分布与单方向粗糙度有所不同,增大粗糙度波长和减少波幅有利于减小压力,增大膜厚,改善润滑.【期刊名称】《润滑与密封》【年(卷),期】2014(039)006【总页数】7页(P49-55)【关键词】角接触球轴承;弹性流体动力润滑;热效应;余弦表面粗糙度【作者】卢宪玖;王优强;律辉;刘昺丽【作者单位】青岛理工大学机械工程学院山东青岛266033;青岛理工大学机械工程学院山东青岛266033;青岛理工大学机械工程学院山东青岛266033;青岛理工大学机械工程学院山东青岛266033【正文语种】中文【中图分类】TH117在研究角接触球轴承的弹流润滑时，通常假设角接触球轴承表面是光滑的，但这与工程实际是不相符的。
任何零部件接触表面都存在粗糙度，且在零部件工作过程中，由于磨损和塑性变形，接触表面的几何参数也会发生微观上的变化，接触表面的几何形貌对润滑状态有直接的影响。
尹晓亮等[1]在考虑粗糙度效应、时变效应、温升效应和润滑剂非牛顿特性的基础上研究了粗糙表面形貌参数对润滑特性的影响，但该研究的对象为线接触，且只考虑了一个表面的横向粗糙度。
高雷鸣等[2]通过数值方法研究了固体表面的横向粗糙峰对钢球与玻璃盘形成的热弹流润滑接触区压力、膜厚及温度分布的影响。
姜明等人[3]研究了纯滑动点接触热弹流润滑在考虑纵向单粗糙峰/单粗糙谷这一因素时，油膜的厚度、压力及温度随粗糙波高度、波长的变化而变化的情况。
三种客观评价泪膜的方法探讨
三种客观评价泪膜的方法探讨殷鸿波;田颜;邓应平【摘要】Assessing tear film properties is essential for the diagnosis of dry eye.Although tear film break-up time and Schirmer scores have been widely accepted,they are single-value parameters and unable to evaluate the dynamics of tear film in an interblink interval.We reviewed three non-invasive and objective methods,including cornealtopography,interferometry and aberrometry.And we also discussed the differences between dry eye patients and normal people detected by these methods.%干眼是以泪液质和量以及动力学异常为特征的一种多因素疾病.目前临床上最常使用的评价泪膜的方法为泪膜破裂时间和泪液分泌实验,两种方法均只能获得单一时点数据,主观性强,且具有一定的创伤性.因此,单纯使用上述指标诊断干眼及其亚型对干眼的基础研究和临床诊疗不利.本文总结了目前已经在临床应用的3种无创的、客观的泪膜评价方法,即角膜地形图、波阵面像差和泪膜干涉仪的测量原理和检测指标,比较正常人群和干眼患者之间测量值的差异,为干眼的精确诊断和治疗提供帮助.【期刊名称】《国际眼科杂志》【年(卷),期】2017(017)005【总页数】3页(P894-896)【关键词】泪膜;干眼;角膜地形图;波阵面像差;干涉仪【作者】殷鸿波;田颜;邓应平【作者单位】10041 中国四川省成都市,四川大学华西医院眼科;10041 中国四川省成都市,四川大学华西医院眼科;10041 中国四川省成都市,四川大学华西医院眼科【正文语种】中文引用：殷鸿波，田颜，邓应平.三种客观评价泪膜的方法探讨.国际眼科杂志2017;17(5):894-896泪膜是覆盖于眼表的一层薄膜，对维持健康眼表和良好视觉具有重要作用。
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1.
Introduction
Although traditional semiconductor quantum dots (SQDs) provide several advantages, such as size-dependent emission wavelength, high-quantum yield, and photostability, many SQDs are made from toxic compounds and concerns have been raised over potential toxicity and environmental harm.1–3 In contrast to SQDs, luminescent carbon dots (CDs) with a low cost possess their favorable attributes without incurring the burden of intrinsic toxicity or elemental scarcity.3 As a consequence, a tremendous amount of attention has been paid to the development for their application in bioimaging, catalysis, sensor, photovoltaic devices, etc.1–4 In fact, the marvelous properties of CDs are associated with quantum-connement effects and structural defects.1,5–16 Theoretical and experimental studies of CDs have indicated that structural defects play a critical role in the creation of energy gaps for emissive electronic transitions.1,5–7 In general, they are easily present on the surface or at the edge at the nanoscale due to the termination of lattice periodicity.1,7–10 If the unpaired electrons in the dangling bonds of surface atoms react with other elements, a new electronic state will form and then
Nanoscale
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Cite this: DOI: 10.1039/c3nr03893a
2.
Experimental section
Preparation of CDs with different surface groups Scheme 1 shows the preparation process. 25 mL ethylene glycol (analytically pure, without dilution) was put into a poly(tetrauoroethylene) (Teon)-lined autoclave (50 mL) and heated at 200 C for 5 h. Aer cooling to rooeme 1 groups.
Illustration of the procedure to prepare CDs with the different surface
Modulation and effects of surface groups on photoluminescence and photocatalytic activity of carbon dots
Shengliang Hu,*ab Ruixue Tian,b Yingge Dong,b Jinlong Yang,bc Jun Liua and Qing Changb
inuence the recombination and/or separation of the photogenerated electron–hole pairs.17,18 For instance, stronger photoluminescence (PL) of CDs can be obtained by replacing the oxygen-contained surface groups with nitrogen-rich surface groups.5,6,11–14 Compared to the OH group at the surface of the CDs, the C]O group can induce faster carrier migration.15 Although signicant advancement in the preparation of nanocomposites containing CDs has been made to improve solar energy conversion or photocatalytic activity,4 few understand the photochemical and photophysical consequences induced by surface-group modulation. It is known that a key issue inuencing the photocatalytic capability is the nature of its surface/interface chemistry.19,20 The surface energy and chemisorption properties play crucial roles in the transfer of electrons and energy, in governing the selectivity, rate and overpotential of redox reactions on the photocatalyst surface.21,22 Therefore, appropriate modication of the surface is frequently necessary to facilitate photocatalysis. In this work, we designed and tailored surface groups of CDs with heteroatoms by a facile and effective approach and found the effects of the different surface groups on photocatalytic activities of CDs. Furthermore, a possible mechanism to tune the photocatalytic activity via surface groups was also proposed.
a
Key Laboratory of Instrumentation Science & Dynamic Measurement, Ministry of Education, Science and Technology on Electronic Test and Measurement Laboratory, Taiyuan 030051, P.R. China. E-mail: hsliang@; Fax: +86 351 3559638; Tel: +86 351 3559638 School of Material Science and Engineering, North University of China, Taiyuan 030051, P.R. China
Nanoscale
b
c State Key Laboratory of New Ceramics and Fine Processing, Tsinghua University, Beijing 100084, P.R. China
This journal is ª The Royal Society of Chemistry 2013
Received 27th July 2013 Accepted 11th September 2013 DOI: 10.1039/c3nr03893a /nanoscale
and directions of energy band bending from inner to surface induced by O, N, and Cl radicals at the surface of CDs. The coexistence of both upward and downward band bending that are caused by the O and Cl radicals, respectively, in CDs is similar to an internal electronic field that facilitates the separation of electron–hole pairs and carrier migration, leading to high photocatalytic activity. These results may also be used for designing and tailoring optical–electronic properties of carbon nanostructures.