人脐静脉内皮细胞形貌与表面粘附力的原子力显微镜表征

目的:探讨原子力显微镜(AFM)在研究人脐静脉内皮细胞(ECV304)表面形貌、超微结构及纳米机械性质等方面的应用,讨论ECV304超微结构和机械性质与其功能的关系。方法:利用AFM对ECV304细胞的表面形貌及生物机械性质进行表征与测量。结果:在AFM下观察到用普通光学显微镜难以观察到的ECV304细胞的独特的形态结构,如细胞骨架、伪足及细胞边缘微丝等。ECV304细胞呈现长梭形、多角形、圆形等多种形态,细胞表面平均粗糙度为320.52±75.98 nm,表面均匀分布微绒毛,细胞周围有铺展的圆盘状物质。力曲线定量分析得出针尖与细胞表面的非特异性粘附力为75±14 pN。结论:通过AFM成像和力曲线测量表明,ECV304细胞呈圆形,多角形,梭形等多种形态,针尖与细胞膜表面问的粘附力比较小,约75±14pN。     

ZrO_2陶瓷生坯表面微织构制备工艺的研究

通过冷等静压技术制备Zr O_2陶瓷生坯,并利用脉冲激光在陶瓷生坯表面制备微织构沟槽。探究激光参数对表面微织构质量的影响,并研究烧蚀区域的热影响区和激光烧蚀表面的微观形态变化。实验结果表明:通过激光加工可以在Zr O_2陶瓷生坯表面加工出深度30-50μm、宽度15-50μm质量较好的微织构沟槽;激光参数对表面加工质量有较大的影响,激光频率低于40Hz、功率低于6W和扫描速度高于200mm/s能够获得较好的表面质量;当激光频率高于60Hz、功率高于10W和扫描速度低于150mm/s时,在激光烧蚀表面容易形成烧蚀层,分析得知烧蚀层是由于在激光高温照射下Zr O_2颗粒的熔化和再凝固形成的。     

谐波齿轮传动考虑表面粗糙度效应时的润滑计算

在计及了表面粗糙度影响后,用基于平均流动模型的平均雷诺方程进一步研究谐波齿轮传动齿面的润滑状态,计算剪切膜和挤压膜的数值解,给出齿面最小油膜厚度曲线.结果表明,齿面表面粗糙度增大,由它所引起的动压效应增强,齿面上的润滑油易存留,能够建立起足够的油膜厚度.     

谐波齿轮传动考虑表面粗糙度效应时的润滑计算

在计及了表面粗糙度影响后,用基于平均流动模型的平均雷诺方程进一步研究谐波齿轮传动齿面的润滑状态,计算剪切膜和挤压膜的教值解,给出齿面最小油膜厚度曲线。结果表明,齿面表面粗糙度增大,由它所引起的动压效应增强,齿面上的润滑油易存留,能够建立起足够的油膜厚度。     

单晶SiC化学机械抛光液化学反应参数研究

选择影响化学机械抛光化学反应速率的参数:催化剂浓度、氧化剂浓度、抛光液的pH值、抛光液温度等进行了试验,研究了它们对基于芬顿反应的单晶SiC化学机械抛光效果的影响规律。发现只有当H_2O_2浓度高于20%、Fe_3O_4浓度高于1.25%时,增大H_2O_2、Fe_3O_4浓度,材料去除率才会显著越高,此时材料去除速率由化学液腐蚀速度与磨料机械去除速度共同决定;低于此范围时由磨料的机械作用决定。温度升高会加速H_2O_2分解,抑制羟基自由基·OH的生成,减缓化学腐蚀,降低材料去除率。当Fe_3O_4浓度、H_2O_2浓度、pH值、抛光液温度分别为1.25%、15%、7、41℃时,化学腐蚀与机械去除的协调性及磨料的分散性较好,表面粗糙度最低;当它们分别为5%、25%、9.3、15℃时,材料去除率最高。     

减小SiO2光波导表面粗糙度的ICP干法刻蚀工艺研究

波导表面粗糙度引起的散射损耗是SiO2光波导传输损耗的主要来源,通过降低表面粗糙度可以获得低损耗SiO2光波导。通过优化ICP干法刻蚀工艺的各参数(如温度、压强、气体流量、感应/偏置功率等)获得了低粗糙度的SiO2光波导,并采用SEM和AFM对刻蚀表面粗糙度进行了定量测试。采用优化刻蚀工艺可将表面粗糙度从35.4nm降低到3.6nm,波导传输损耗约为0.1dB/cm。     

离子后处理对TiO2光学薄膜及损伤特性的影响

为了进一步提高TiO_2薄膜的光学特性和激光损伤阈值,采用电子束蒸发技术在K9玻璃上沉积了单层TiO_2薄膜,并用Ar/O混合等离子体对样品进行后处理。通过研究薄膜光谱特性、表面缺陷密度、薄膜表面形貌、薄膜损伤阈值以及薄膜损伤形貌,分析了等离子体后处理时间对TiO_2薄膜激光损伤特性的影响。实验结果表明,随着等离子体后处理时间的增加,薄膜折射率及致密度提高,物理厚度减少,表面粗糙度下降,表面缺陷密度先减少后增加;在1 064nm激光辐射下,TiO_2薄膜的激光损伤阈值从未经等离子后处理的5.6J/cm~2提升至后处理20min的9.65J/cm~2,提升幅度高达72.3%,因此能够更广泛更稳定地应用在激光器中。     

湿法化学刻蚀技术处理抛光熔石英元件

为了提高熔石英元件的抗激光损伤能力,采用基于氢氟酸刻蚀的湿法化学技术去除元件内的激光损伤诱因。利用不同的氢氟酸溶液处理经氧化铈抛光的熔石英元件,并对元件的刻蚀速率、表面洁净度、粗糙度、透过率和激光损伤性能进行评价。研究结果表明,与传统的静态刻蚀相比,在质量分数为6%的氢氟酸刻蚀溶液中引入能量密度约为0.6 W/cm^2的兆声能量对元件的溶解速率和激光损伤性能没有明显的提升作用;化学刻蚀产生的沉积物对元件表面粗糙度和透过率均有不利影响,且沉积物比例与所用的刻蚀液成分和浓度密切相关;经质量分数6%或12%的纯氢氟酸溶液刻蚀(5±1)μm深度后,熔石英元件的激光损伤阈值相比于未刻蚀元件提升了约1.9倍;熔石英元件的激光损伤性能与表面粗糙度和透过率之间不是简单的线性关系,但激光损伤阈值较理想的元件(>20 J/cm^2@3ns)往往具有较光滑的表面,即表面粗糙度<2 nm,由此可以确定有利于熔石英元件激光损伤性能的刻蚀条件,并获得元件表面粗糙度的控制指标。     

SnO2导电薄膜的制备与研究

采用R．F反应溅射法制备SnO2导电薄膜，用XRD、AFM、XPS研究了薄膜的结构和组成对导电性能的影响。XRD和AFM研究表明，随着衬底温度的增加，SnO2薄膜从非晶向多晶结构转变，表面粗糙度减弱，薄膜的表面电阻大幅增加。采用XPS对薄膜表面成分进行分析，时不同衬底温度下Sn3d5／2拟合发现，薄膜表面存在Sn^2＋和Sn^4＋两种混合价态。随着村底温度的增加，Sn3d5／2能谱位置与峰宽并没有变化。对O1s能谱进行Gaussian拟合后发现，薄膜表面的氧以晶格氧（略）和化学吸附氧（Oahs^-）两种方式存在。实验证明，Oabs^-含量与SnO2表面电阻成正比关系。     

基于清洗表面形貌的AH32钢激光除锈机制

为了获得纳秒激光除锈工艺规律并揭示除锈机理,研究了不同工艺参数下激光除锈后AH32船用钢的表面形貌与粗糙度。采用纳秒脉冲激光器在不同工艺参数下对试样表面锈层进行激光清洗,使用激光共聚焦显微镜测量清洗表面粗糙度,基于扫描电镜观察清洗表面微观形貌,借助能谱分析仪进行清洗表面元素分析。最后,结合试验结果揭示了AH32船用钢的纳秒激光除锈机制。试验结果表明:在3 000mm/s的扫描速度下分别采用30.6J/cm2和10.2J/cm2的激光能量密度对AH32船用钢表面锈层进行分步激光清洗,可以显著改善清洗形貌并降低表面粗糙度。微观形貌分析发现在上述清洗条件下,基体表面呈现微熔状态,光斑内部光滑均匀,边缘分布枝晶状乳突结构。分步激光清洗工艺可以获得较好的清洗效果和较高的清洗效率,其除锈机制主要包括孔洞爆破机制和烧蚀蒸发机制。     

钛合金激光清洗及其对激光焊接气孔的影响

采用砂纸打磨、酸洗、激光清洗等方式对Ti6Al4V钛合金进行焊前清洗。通过扫描电镜、白光干涉仪、能谱仪分析了各种清洗方式下的表面形貌、粗糙度和化学成分，研究了不同清洗方式及参数对清洗效果的影响。在均匀熔透和表面质量良好的同一激光焊接条件下，比较了不同清洗条件对气孔率的影响。合适的激光清洗可有效清除焊接试件表面氧化层，并改善表面粗糙度，得到较低的气孔率，其焊缝可达到中国航天工业行业标准I级焊缝要求。     

Effect of Er:YAG laser irradiation on deciduous enamel roughness and bacterial adhesion: An in vitro study

Laser irradiation has been proposed as a preventive method against dental caries since it is capable to inhibit enamel demineralization by reducing carbonate and modifying organic matter, yet it can produce significant morphological changes. The purpose of this study was to evaluate the influence of Er:YAG laser irradiation on superficial roughness of deciduous dental enamel and bacterial adhesion. Fifty‐four samples of deciduous enamel were divided into three groups (n = 18 each). G1_control (nonirradiated); G2_100 (7.5 J/cm²) and G3_100 (12.7 J/cm²) were irradiated with Er:YAG laser at 7.5 and 12.7 J/cm², respectively, under water irrigation. Surface roughness was measured before and after irradiation using a profilometer. Afterwards, six samples per group were used to measure bacterial growth by XTT cell viability assay. Adhered bacteria were observed using confocal laser scanning microscopy (CLSM) and a scanning electron microscopy (SEM). Paired t‐, one‐way analysis of variance (ANOVA), Kruskal‐Wallis and pairwise Mann–Whitney U tests were performed to analyze statistical differences (p < .05). Before treatment, samples showed homogenous surface roughness, and after Er:YAG laser irradiation, the surfaces showed a significant increase in roughness values (p < .05). G3_100 (12.7 J/cm²) showed the highest amount of Streptococcus mutans adhered (p < .05). The increase in the roughness of the tooth enamel surfaces was proportional to the energy density used; the increase in surface roughness caused by laser irradiation did not augment the adhesion of Streptococcus sanguinis; only the use of the energy density of 12.7 J/cm² favored significantly the adhesion of S. mutans.     

飞秒激光抛光CVD金刚石涂层表面

为了实现降低金刚石涂层粗糙度的目的,本文研究了飞秒激光功率,重复频率以及扫描速度对金刚石涂层表面粗糙度的影响,试验之后利用白光干涉仪检测抛光区域形貌以及粗糙度。试验结果表明：粗糙度随着功率的降低而减小,当功率降至100 mw以下时抛光后的粗糙度会随着功率的降低而略微的提高;重复频率对抛光后的粗糙度无显著影响;粗糙度随扫描速度的增大而减小,当扫描速度增加到1.6 mm/s之后,粗糙度会出现略微的升高。在功率100 mw,重复频率1 KHz,扫描速度1.6 mm/s的条件下,得到的粗糙度最低,约为0.14 μm,局部区域粗糙度可降至100 nm以下,并且抛光的区域相对于未抛光区域更具有致密性,基本上满足金刚石涂层低摩擦表面的要求。     

Pulsed Nd:YAG laser treatment of monocrystalline silicon substrate

To minimize reflection and increase the opportunity for photovoltaic (PV) devices to absorb incident light, we produced rough-textured surfaces using a pulsed Nd:YAG laser. We investigated the effect of various operating parameters on surface features and optical performance. The parameters investigated were pulse repetition frequency, pulse energy, and textured surface exposure time. Following laser surface treatment, no chemical solution etching or anti-reflective coatings were necessary. Reflectance values were measured by spectrophotometer. Structural properties including surface morphology and surface roughness of the textured surfaces were analyzed by a three-dimensional confocal laser scanning microscope. The resulting surface reflection curves indicated that, of the different laser machining paths, the vertical and circular paths produced identical optical properties in the samples. Surface reflection values decrease as the pulse energy and exposure times increase. By contrast, surface roughness increases with exposure time. An increase in pulse frequency reduces surface roughness, although the extent of the reduction depends upon the pulse energy. Following surface texturing of the monocrystalline silicon samples, the total reflection was reduced from 40% to approximately 10% of incident light. Our experimental results indicate that the rougher surfaces attained by laser surface treatment provide better light-trapping properties for PV devices.     

Surface characteristics of aluminum 6061-T6 subjected to Nd:YAG pulsed-laser irradiation

The objective of this study was to investigate the surface characteristics of an aluminum 6061-T6 alloy subjected to Nd:YAG pulsed-laser irradiation. The test specimens were prepared by a mechanical polishing process using diamond paste and emery polishing paper to obtain different levels of initial surface roughness. After ten pulsed-laser shots, the surface morphology was observed via optical microscopy (OM) and scanning electron microscopy (SEM). Nano-indentation hardness testing was also conducted on the irradiated surface. The diameter of the melted zone increased with surface roughness because of the multiple reflection and absorption of the laser beam. The relative absorbance was measured as a function of the diameter of the melted zone with varied surface roughness.     

A microscopic analysis of the effects of root surface scaling with different power parameters of er,cr:YSGG laser

The aim of this study was to evaluate the effects of different power parameters of an Erbium, Cromium: Yttrium, Scandium, Gallium, Garnet laser (Er,Cr:YSGG laser) on the morphology, attachment of blood components (ABC), roughness, and wear on irradiated root surfaces. Sixty‐five incisive bovine teeth were used in this study, 35 of which were used for the analysis of root surface morphology and ABC. The remaining 30 teeth were used for roughness and root wear analysis. The samples were randomly allocated into seven groups: G1: Er,Cr:YSGG laser, 0.5 W; G2: Er,Cr:YSGG laser, 1.0 W; G3: Er,Cr:YSGG laser, 1.5 W; G4: Er,Cr:YSGG laser, 2.0 W; G5: Er,Cr:YSGG laser, 2.5 W; G6: Er,Cr:YSGG laser, 3.0 W; G7: scaling and root planning (SRP) with manual curettes. The root surfaces irradiated by Er,Cr:YSGG at 1.0 W and scaling with manual curettes presented the highest degrees of ABC. The samples irradiated by the Er,Cr:YSGG laser were rougher than the samples treated by the manual curette, and increasing the laser power parameters caused more root wear and greater roughness on the root surface. The Er,Cr:YSGG laser is safe to use for periodontal treatment, but it is not appropriate to use irradiation greater than 1.0 W for this purpose. Microsc. Res. Tech. 78:529–535, 2015. © 2015 Wiley Periodicals, Inc.     

K2Cr2O7溶液红移现象研究

通过对酒石酸钾为溶剂的K2C r2O7溶液在不同浓度下的圆二向色性进行测试,显示出该溶液对波长在500nm-700nm范围内的光表现出明显的圆二向色性,而且其圆二向色性随溶液浓度的降低而减弱,同时也发现该溶液的最大吸收波长出现红移现象,波长漂移量可达5.5nm。     

Investigating the Machinability of Al–Si–Cu cast alloy containing bismuth and antimony using coated carbide insert

Surface roughness and cutting force are two key measures that describe machined surface integrity and power requirement evaluation, respectively. This investigation presents the effect of melt treatment with addition of bismuth and antimony on machinability when turning Al–11%Si–2%Cu alloy. The experiments are carried out under oblique dry cutting conditions using a PVD TIN-coated insert at three cutting speeds of 70, 130 and 250 m/min, feed rates of 0.05, 0.1, 0.15 mm/rev, and 0.05 mm constant depth of cut. It was found that the Bi-containing workpiece possess the best surface roughness value and lowest cutting force due to formation of pure Bi which plays an important role as a lubricant in turning process, while Sb-containing workpiece produced the highest cutting force and highest surface roughness value. Additionally, change of silicon morphology from flake-like to lamellar structure changed value of cutting force and surface roughness during turning.     

铜带轧制变形区摩擦润滑状态研究

观察分析了轧制变形区形貌特征,研究了不同方向粗糙度对轧制润滑的影响。在轧制变形区并存边界润滑和流体动压润滑;轧辊与轧制的塑性挤压边界接触是获得高光亮表面的必要条件。轧后轧件表面粗糙度Ｒａ和丰满度Ｋ趋向于满足一定润滑条件的最佳值。     

LED蓝宝石衬底抛光表面原子台阶形貌及其周期性研究

LED蓝宝石衬底的表面质量会极大影响到后续外延质量,进而影响到LED器件性能。蓝宝石研磨片经Al2O3磨粒粗抛液、SiO2磨粒精抛液下进行化学机械抛光(CMP),最终表面经原子力显微镜(AFM)所测表面粗糙度达到0.101nm,获得亚纳米级粗糙度超光滑表面,并呈现出原子台阶形貌。同时,通过使用Zygo表面形貌仪、AFM观察蓝宝石从研磨片经Al2O3粗抛液、SiO2精抛液抛光后的表面变化,阐述蓝宝石表面原子台阶形貌的形成原因,提出蓝宝石原子级超光滑表面形成的CMP去除机理。通过控制蓝宝石抛光中的工艺条件,获得a-a型、a-b型两种不同周期规律性的台阶形貌表面,并探讨不同周期规律性台阶形貌的形成机理。