精密表面疵病检测美标数字化评价实现算法

采用美国军用标准MIL-PRF-13830B（简称美标）对光学元件表面疵病进行数字化评价,其难点主要在于美标中表面疵病密集度的判定。针对该难点,提出了一种表面疵病密集度判定算法。该算法采用权重域叠加的方法,通过为表面疵病赋予相应的权重域来确定疵病密集圆域,并将权重域间的叠加转换成了矩阵间位置关系的判断和计算,有效的利用了矩阵运算的便利性。实验中通过对已知表面疵病信息的石英标准板进行判定,其得到的圆域即为疪病密集圆域,与预期结果一致,验证了该算法的正确性。目前该算法已经运用于光学车间精密光学元件表面疵病的美标数字化评价。     

Tuning field emission properties of boron nanocones with catalyst concentration

Single crystalline boron nanocones are prepared by using a simple spin spread method in which Fe 3 O 4 nanoparticles are pre-manipulated on Si(111) to form catalyst patterns of different densities.The density of boron nanocones can be tuned by changing the concentration of catalyst nanoparticles.High-resolution transmission electron microscopy analysis shows that the boron nanocone has a β-tetragonal structure with good crystallization.The field emission behaviour is optimal when the spacing distance is close to the nanocone length,which indicates that this simple spin spread method has great potential applications in electron emission nanodevices.     

Surface-enhanced Raman scattering properties of highly ordered self-assemblies of gold nanorods with different aspect ratios

Gold nanorods with aspect ratios of from 1 (particles) to 31.6 were synthesized by the seed-mediated method and packed in a highly ordered structure on a large scale on silicon substrates through capillary force induced self-assembly behaviour during solvent evaporation.The gold nanorod surface exhibits a strong enhancing effect on Raman scattering spectroscopy.The enhancement of Raman scattering for two model molecules (2-naphthalenethiol and rhodamine 6G) is about 5-6 orders of magnitude.By changing the aspect ratio of the Au nanorods,we found that the enhancement factors decreased with the increase of aspect ratios.The observed Raman scattering enhancement is strong and should be ascribed to the surface plasmon coupling between closely packed nanorods,which may result in huge local electromagnetic field enhancements in those confined junctions.     

双氯芬酸钠缓释液体栓制备与体内外相关性研究

设计制备了以泊洛沙姆407/188为主要基质,卡波姆、氯化钠为添加剂,月桂酸二乙醇酰胺为增溶剂的双氯芬酸钠缓释液体栓,以凝胶温度、凝胶强度、生物黏附力和体外释放度为考察指标进行体外评价;测定双氯芬酸钠缓释液体栓在犬体内的血药浓度,进行体内筛选.采用3p97软件计算液体栓相关药动学参数,进行体内释药特性研究.加入0.9%月桂酸二乙醇酰胺使双氯芬酸钠增溶2.3倍.缓释液体栓体外释放符合零级模式,R20.9,释药时限大于6h;体内药物释放出现血药平台,具有良好的体内外相关性;体内过程为一室模型,t1/2(Ke)=5.553 3h,t1/2(Ka)=0.357 4h,cmax=7 712ng.mL-1,AUC0→∞=72 029ng.h.mL-1,MRT=7.61h.所制备的双氯芬酸钠缓释液体栓具有稳定的缓控释特性.     

Influence of tube voltage and current on in-line phase contrast imaging using a microfocus x-ray source

In-line x-ray phase contrast imaging has attracted much attention due to two major advantages: its effectiveness in imaging weakly absorbing materials, and the simplicity of its facilities. In this paper a comprehensive theory based on Wigner distribution developed by Wu and Liu [Med. Phys. 31 2378-2384 (2004)] is reviewed. The influence of x-ray source and detector on the image is discussed. Experiments using a microfocus x-ray source and a CCD detector are conducted, which show the role of two key factors on imaging: the tube voltage and tube current. High tube current and moderate tube voltage are suggested for imaging.     

利用Al/AlAs中间层调控GaAs在Si(111)上外延生长的研究

为了实现Ⅲ-V器件在硅基平台上单片集成,近年来Ⅲ-V半导体在硅衬底上的异质外延得到了广泛研究。由于Ⅲ-V半导体与Si之间大的晶格失配以及晶格结构不同,在Si上生长的Ⅲ-V半导体中存在较多的失配位错及反相畴,对器件性能造成严重影响。而Si(111)表面的双原子台阶可以避免Ⅲ-V异质外延过程中形成反相畴。本文利用分子束外延技术通过Al/AlAs作为中间层首次在Si(111)衬底上外延生长了GaAs(111)薄膜。通过一系列对比实验验证了Al/AlAs中间层的插入对GaAs薄膜质量的调控作用,并在此基础上通过低温-高温两步法优化了GaAs的生长条件。结果表明Al/AlAs插层可以为GaAs外延生长提供模板,并在一定程度上释放GaAs与Si之间的失配应力,从而使GaAs薄膜的晶体质量得到提高。以上工作为Ⅲ-V半导体在硅上的生长提供了新思路。     

N,N-二甲基碘化铵:染料敏化太阳能电池钙钛矿前驱体电解质的高效添加剂

钙钛矿前驱体（PbI₂和CH₃NH₃I）分散体系，作为一种新型染料敏化太阳能电池（Dye-sensitized Solar Cells，DSSCs）电解质，光电流和光电压的继续提升是其发展过程中亟待解决的问题.在本工作中，研究发现，通过引入二甲基碘化铵（DMAI）作为钙钛矿前驱体电解质的高效添加剂，可将光电流密度从12.85 mA·cm^-2急剧提升至19.19 mA· cm^-2.借助阻抗和塔菲尔曲线分析，发现其光电流的增加与TiO₂半导体导带的向上移动对不平衡载流子复合的抑制作用具有一定的相关性.进一步通过叔丁基吡啶的调节作用，可将光电转换效率提高到8.46%，超过了传统的碘电解质.也为染料敏化太阳能电池的研究开辟了新的途径.     

3种基源莪术的显微及理化鉴定

对莪术的3种基源生药进行显微及理化鉴定,建立1种简单易行的方法作为不同基源莪术的鉴定依据。通过显微成像系统观察莪术切片和粉末的显微特征,绘制墨线图;采用水蒸气蒸馏法提取莪术的挥发油,进行薄层色谱分离。3种基源莪术在显微鉴定及理化鉴定方面均存在较大差异可作为药材的鉴定依据。     

丹磺酰氯柱前衍生-超高效液相色谱-串联质谱法测定人体尿样中的环己胺

建立丹磺酰氯柱前衍生-超高效液相色谱-串联质谱法测定人体尿样中环己胺的方法。冷冻样品经解冻、离心后,用丹磺酰氯衍生,固相萃取小柱净化。目标化合物采用 Waters ACQUITY CSHTM C18色谱柱(50 mm×2.1 mm,1.7μm)分离,以甲醇和0.002 mol/L乙酸铵溶液为流动相梯度洗脱,采用电喷雾离子源电离、正离子多反应监测模式质谱检测。环己胺在2.5~200μg/L浓度范围内有较好的线性关系,相关系数大于0.999,回收率为98.7%~102.3%,精密度为3.1%~5.2%,检出限和定量限分别为1.0和3.0μg/L。结果表明,本方法操作简单、准确可靠,可适用于人体尿液中环己胺的定量分析。应用本方法测定200份学生尿液样品,环己胺检出率为34.5%。     

线性、径向和环向偏振飞秒激光诱导非晶合金周期性表面结构

研究在复杂偏振条件下,飞秒激光诱导非晶合金Zr44Ti11 Cu10Ni10Be25(at％)表面周期性结构的形成机理.实验采用波长800 nm、脉宽120 fs的超短脉冲激光,分别在线性、径向、环向偏振条件下,诱导非晶合金表面生成复杂的周期性表面结构.表面结构由周期为652～723 nm的低频条纹和周期为1 304～1 765 nm的微型条纹组成.通过有限差分时域法仿真分析,发现微型条纹由粗糙表面引起的定向调制的表面散射电磁波与入射激光干涉形成.仿真结果与实验结果一致,验证了微型条纹形成机理的有效性.