镁合金表面磁控溅射沉积铝膜的力学性能

采用直流磁控溅射法在镁合金上沉积铝膜,在高真空下对铝膜进行加热后处理. 用X射线衍射仪(XRD)分析膜层为纯铝多晶态,扫描电子显微镜(SEM)观察铝膜晶粒细小. 采用纳米压痕/划痕仪对铝膜的厚度、临界附着力、硬度和弹性模量进行了测试,并且用辉光放电光谱仪(GDS)测试了镁合金表面铝膜的成分和性能随薄膜深度的分布. 结果表明,铝膜的厚度随后处理温度的升高而降低,其表面硬度和弹性模量高于镁合金基体并且随深度增加而逐渐降低. 铝膜与镁合金基体间存在一个过渡层,结合良好且表现出一定的弹塑性能,有利于镁合金表面的防护.     

Sol-甩膜法制备钛酸钡薄膜及其微观形态的SPM研究

采用溶胶-凝胶(Sol-Gel)法合成稳定的前驱体溶液,在单晶硅(100)上用甩膜法制得了均匀致密的钛酸钡薄膜,利用差热-热重(DTA-TGA)技术分析了钛酸钡(BT)干凝胶的热演化过程,首次用电子探针显微镜(SPM)之原子力显微镜(AFM)直接地从三维的角度观测了钛酸钡薄膜微观形成过程,并用XRD技术跟踪了薄膜加热过程中物相的变化情况,得到了薄膜生长的基本信息,最终制得了表面光滑的钛酸钡薄膜,晶粒大小在50-70nm之间。最佳煅烧温度为700℃。     

缓冲层对银薄膜光电特性的影响

研究铜、铝作为银薄膜的缓冲层对银薄膜的光电学性质的影响.利用热蒸发技术在BK-7玻璃基底上沉积Ag(220 nm)/Al(20 nm)和Ag(220 nm)/Cu(20 nm)薄膜,沉积薄膜在温度为400、500℃的大气条件下退火处理1 h.样品的表面形貌用原子力显微镜观测,光学和电学性质分别用分光光度计和vander Pauw方法测量.实验结果表明,相对于同等条件下制备的纯银薄膜,附加缓冲层大大提高了退火态薄膜的光电性质,改善了银薄膜的热稳定性.不同的缓冲层对银薄膜光电性质影响程度不同:在同一退火温度下,在可见光谱区域,Ag/Al薄膜的反射率大于Ag/Cu薄膜;Ag/Cu薄膜的电阻率ρ小于Ag/Al薄膜,且在退火温度为500℃时Ag/Cu薄膜的ρ最小.     

铁磁性薄膜表面粗糙度对系统磁特性的影响

以简单立方结构单原子层逐层生长模型用Monte Carlo算法模拟研究了表面粗糙度对薄膜磁特性的影响.模拟结果表明表面粗糙度需要根据具体的薄膜结构分别定义为γ 和γ-,这两种情况下的系统磁特性随粗糙度的变化趋势有相当大的不同.同时,发现配位数直接影响表面粗糙度,进而间接影响热磁化强度M以及居里温度Tc等磁特性.     

Silk Fibroin Film Blended with Poly（ ethylene glycol-glycerin）

To improve the toughness of silk fibroin（ SF） films,poly（ ethylene glycol-glycerin）（ PEGG） was synthesized with ethylene glycol and epichlorohydrin. The SF / PEGG blend films were prepared by casting aqueous solution and their structures were characterized. The PEGG was in liquid state at room temperature so it will not be a single phrase at blend film. It crosslinked with SF and made it insolubility in water. The results of X-ray diffraction（ XRD） indicated that the crystallinity of the SF in the blend films decreased with the content of PEGG increasing. The tensile strength and elongation at break of blend films were measured using an instron tensile tester. The results showed that the tensile strength and elongation at break of blend films were high enough for application.After the blend films were stored at room temperature for 100 d,the crystallinity, the tensile strength and elongation at wet state increased. The blend films are superior to SF films in providing excellent flexibility and mechanical properties in both dry and wet states. Based on the fact that SF has good biocompatibility,the SF /PEGG blend film will offer new options in many different biomedical applications.     

染料敏化太阳能电池中多孔电极制备及性能

将喷涂法应用于制备染料敏化太阳能电池光阳极,具有浆料制备简单、易操作、成本低廉等优势.本文以钛酸丁酯和P25为原料配制浆料,采用喷涂法制备二氧化钛薄膜,选择乙二醇作为造孔剂,探索了乙二醇的最佳加入量.通过对电池I-V曲线,二氧化钛薄膜表面粗糙度、染料吸附量和漫反射谱,以及光阳极的扫描电镜照片和交流阻抗图谱的分析,得到如下结果:当乙二醇与钛酸丁酯的体积比为1∶1时,二氧化钛薄膜的粗糙度最大,即孔隙率和比表面积最大,因此染料吸附量达到1.47×10-7mol·cm-2,电池性能最好,其中开路电压为0.69 V,短路电流为13.0 m A·cm-2,光电转化效率达到5.38%,比不加造孔剂时增加了将近1倍,此时电子的扩散转移电阻也最小.     

锌对316L奥氏体不锈钢氧化膜影响的XPS分析

通过模拟压水堆-回路高温高压水化学环境,对316L奥氏体不锈钢进行了10、60和120μg/L锌浓度下的动水加锌实验,用X射线光电子能谱(XPS)对其表面氧化膜结构进行分析.结果表明,加锌能有效降低材料的腐蚀速率,在一定范围内加锌浓度(10~60μg/L)越高,腐蚀增重越小;锌对铁镍尖晶石结构中的Fe2+和Ni 2+有替换作用,形成稳定的ZnCr2O4.     

Preparation of CoP films by ultrasonic electroless deposition at low initial temperature

Electroless deposition technology has been considered as a kind of common ways to obtain cobalt alloy films. However, in order to get cobalt alloy films, high temperature(353 K) is necessary during the electroless deposition process which will increase costs and energy consumption. Ultrasonic was introduced during electroless plating process to obtain cobalt alloy films at lower initial temperature. It was found that the cobalt thin films could be prepared at lower initial temperature(323 K) with the introduction of ultrasonic. Therefore, different powers of ultrasonic were applied during the electroless deposition process to prepare CoP thin films on copper substrates from an alkaline bath in this investigation. The effects of different powers of ultrasonic on deposition rate, surface morphology, anticorrosion performance and magnetic property of films were studied. It was found that the deposition rate increased gradually with the rise in ultrasonic powers due to cavitation phenomenon. All the CoP films presented the typical spherical nodular structures with the impact of ultrasonic. Smaller and regular shaped structures could be observed when the films were deposited with higher power of ultrasonic which contributed directly to enhancement of anticorrosion performance. Saturation magnetization and coercivity of thin films increased gradually with the rise in ultrasonic powers during the electroless deposition process due to the higher amounts of cobalt.& 2014 Chinese Materials Research Society. Production and hosting by Elsevier B.V. All rights reserved.     

碱浸处理对壳聚糖膜性质的影响

分别通过浇铸-蒸发法和浇铸-蒸发-碱浸法制备了壳聚糖膜,采用扫描电镜(SEM)、Fourier红外光谱(FT-IR)、X射线衍射(XRD)对膜的微观结构进行了表征,并分析了碱浸处理对膜的外观形貌、厚度、拉伸强度、断裂伸长率、可挥发物含量、接触角、水蒸气透过系数、总溶解物含量和溶胀指数等性质的影响.结果表明:碱浸处理将膜中的壳聚糖乙酸盐还原为壳聚糖,降低了膜中共价键的振动强度,但对膜的表面形貌没有影响.壳聚糖膜经过碱浸处理后,其厚度、可挥发物含量、总溶解物含量、溶胀性都减小,其接触角、拉伸强度、断裂伸长率都增大.碱浸法处理提高了壳聚糖膜的机械性能和防水性能.研究结果为经过碱浸处理的壳聚糖膜的实际应用提供了技术依据.     

湖北农产品指标的主成分分析

文章以多元统计中的主成分分析法为依据,使用软件SAS8．2对2006年＆．2007年湖北主要农产品指标进行分析．