正常人脐静脉内皮细胞的原子力显微镜观察

目的:利用原子力显微镜(AFM)在单细胞水平分析正常人脐静脉内皮细胞的形貌特征和机械性质,为了解内皮细胞结构与功能的关系奠定基础.方法:新鲜人脐静脉内灌注质量分数为0.25%胰蛋白酶消化,获得人脐静脉内皮细胞(HUVECs),M199培养基进行培养,免疫细胞化学检测内皮细胞第Ⅷ因子的表达.将体外培养的HUVECs用质量...     

热处理对镍基合金涂层与基体结合界面的影响

通过热浸镀法在普碳钢表面成功制备镍基合金涂层.为了提高镍基合金涂层与钢基体之间的结合强度,对镀有镍基合金涂层的基体进行了热处理.研究了热处理前、后结合界面处的显微组织和力学性能.结果表明,与热处理前相比,热处理后界面附近的涂层中析出物长大,界面处存在不连续块状铁的硼化物,界面两侧镍、铁互扩散距离增加,靠近界面的过渡带由5～8μm变为20μm.热处理前、后涂层均由γ-(Fe,Ni)、CrB、Cr2B和Cr3C2等相组成,过渡带相组成为γ-(Fe,Ni)、微量CrB和Fe23(C,B)6.热处理后,显微硬度由界面向涂层内逐渐增加,界面结合强度由140MPa提高到200MPa.     

树叶状CuO微结构:低温水浴合成、影响因素和光催化降解性能

以CuCl2·2H2O和NaOH为起始反应物,在没有任何表面活性剂或模板的辅助下,于80℃的水浴中恒温60 min,快速合成了树叶状的CuO微结构.利用X-射线粉末衍射仪和场发射的扫描电子显微镜对所得产物的物相和形貌进行了系统的表征,并调查了起始反应物的摩尔比、反应的温度和时间等实验参数对最终产物形貌的影响.实验显示,所得的树叶状的CuO微结构在365nm的紫外光的照射下具有强烈的促进有机小分子降解的能力.这在环境治理与防护领域有潜在的应用.     

基于真彩切片的MRI图片颜色迁移及三维重构分析

借助于可视人工程的真彩图片作为常用MRI、CT等灰度图片彩色化的颜色迁移的彩色特性源本,以MRI切片和真彩图片的亮度、纹理和几何作为映射间的配准参数而进行合理的颜色转换,以弥补医学灰度图片伪彩色方案中各组织非对应的彩色映射关系.通过真彩图片与灰色图片的亮度分布曲线的调整和纹理特征关系的调整和配准而到有效和符合真实人体器...     

Influence of B,Al and Nb addition on the glass forming ability and stability of mechanically alloyed Zr-Ni amorphous alloys

We investigated the influence of minor additions of B,Al and Nb that have representative atomic sizes on the glass forming ability (GFA) and stability of Zr-Ni amorphous alloys during mechanical alloying. The results show that the minor addition of B,Al or Nb does not shorten the initial time of the full amorphization reaction or improve the glass forming ability of the Zr-Ni alloys at a low rotation speed. However,B addition can effectively improve the mechanical stability of the amorphous phase against me...     

Role of locust <Emphasis Type="Italic">Locusta migratoria manilensis</Emphasis> claws and pads in attaching to substrates

The present study attempts to investigate the role of rigid claws and smooth adhesive pads in the locust Locusta migratoria manilensis,when attaching to various substrates.We measured the attachment forces on sandpaper and silicate glass plate of locusts with intact attachment system,and those with either the pretarsal claws or the tarsal pads having been entirely destroyed,to explore the role of pads and claws when a locust is walking on various substrates.To obtain information about morphological characteristics and material properties of the claws,we examined the intact and fractured claws by scanning electron microscopy,and tested the fractural force in a fracture experiment.We proposed a mechanical model for locust climbing on a slanting surface to analyze the conduction and final result of the attachment forces generated by the attachment organs on the fore-,mid-and hindlegs.Attachment forces generated by locusts with destroyed pads were similar to those generated by locusts with intact attachment system on both substrates,which presumably indicated that the claws have a significantly important role when attaching to various substrates.The result of the fracture experiment demonstrated that the claws are made of relatively stiff material,and their shear strength ranged between 39-45 MPa.Mechanical analysis of locust climbing on slanting surface showed that the force generated by the hindlegs suspended the whole body of locust up from the surface and pushed the body forward,while the midlegs steadily suspended the centre of gravity and the forelegs pulled the suspended body forward.The results obtained contribute to the further interpretation of the interaction mechanisms between insect attachment system and substrates,and supply information for designing and manufacturing slippery plates for trapping plague locusts.     

基于扫描电子显微镜的单根一维纳米材料原位场发射性能研究

基于扫描电子显微镜和纳米探针技术,展示了一维纳米材料原位场发射的测量方法和实例。实验以钨针尖为接收极,纳米材料为发射极,通过结合扫描电子显微镜的实时成像功能,纳米探针的精确操纵及电学测量技术以及激光辐照功能,系统研究了极间距离D、形貌变化、吸附气体和激光注入对单根多壁碳纳米管和氧化锌纳米线场发射性能的影响。结果表明,当D远小于纳米材料长度L的3倍时,D越小,开启场强和阈值场强越大,场发射性能越弱。此外,纳米线尖端曲率半径越大,场增强因子越小,场发射性能越弱。研究还发现O2的脱附和激光辐照有助于纳米材料场发射性能的提高。     

含纳米银的抗菌水凝胶研究

 为赋予水凝胶的抗菌性能,该文对含有纳米银的水凝胶进行了研究。首先在硝酸银溶液加入硼氢化钠还原剂和聚乙烯砒咯烷酮分散剂,合成纳米银;然后将不同体积的纳米银分散液加入到卡波姆溶液中,搅拌下滴加氢氧化钠溶液,制备含纳米银的水凝胶。紫外-可见光谱法的结果表明硝酸银被还原成纳米银,X-射线粉末衍射法证实纳米银被分散在水凝胶中,并通过Scherrer公式计算出纳米银的尺寸约为5 nm。溶胀性能测试结果表明水凝胶的溶胀率约为900%。抑菌性能测试结果显示,当水凝胶中纳米银浓度为10 μg/mL（低于纳米银的安全浓度25 μg/mL）,水凝胶能有效抑制大肠杆菌和金黄色葡萄球菌的生长。所制备的抗菌水凝胶可望应用于创伤皮肤和皮肤疾病的外用治疗。     

大型衍射光栅刻划机控制系统研究

介绍了大型高精度衍射光栅刻划机的机械结构及其控制系统设计,并针对具有复杂机械结构的控制系统研究了一种新的仿真方法.通过利用Pro/Mechanism模块中的Custom Load(定制负荷)插件实现控制算法,从而在虚拟样机上实现运动控制的仿真.采用这种方法,在光栅刻划机上进行了精定位控制仿真,并基于仿真结果进行控制方案优化,提高了控制系统的开发效率和控制方案的有效性.     

Mn:CdTe量子点的水相合成及荧光性质

采用水相合成法合成了Mn2+掺杂CdTe量子点(Mn:CdTe d-dots).通过荧光光谱(PL)分析、原子力显微镜(AFM)和X线粉末衍射(XRD)分析、电子能谱(EDS)分析对产物进行了表征.研究了反应时间、温度、Mn2+掺杂量、pH值及巯基丙酸(MPA)与镉离子的比例对掺杂量子点发光性能的影响.结果表明:反应时...