尿酸结石患者尿液中纳米微晶的形貌、组分和元素分析

采用X射线衍射仪(XRD)、高分辨率透射电子显微镜(HRTEM)以及附带的快速傅里叶变换(FFT)和能谱分析(EDS)对尿酸(UA)结石患者尿液中纳米微晶的形貌、组分和元素进行了分析.纳米尿微晶的主要组分为UA,并含有少量一水草酸钙(COM)和磷酸盐.这表明,尿液中的大量纳米UA晶体的存在是UA结石形成的重要原因;高尿酸尿症、酸性尿以及结石抑制剂的缺失是UA结石形成的危险因素.本文有助于深入了解UA结石的形成机理.     

基于一维光子晶体带隙反射的YAG激光防护镜

设计并制备了一种以磷酸盐玻璃为衬底的一维光子晶体YAG激光防护镜。其中一维光子晶体的带隙反射1．06μm波长的光(透射率低达10^-7),加上磷酸盐玻璃对1．06μm波长光的强吸收作用(透射率约1％),使该防护镜足以防护全方位入射的、脉冲能量密度1J／cm^2以下的ns-脉冲YAG激光对人眼的伤害,而器件对可见光的透射率高达70％以上,而且可以避免反射光对他人的二次反射伤害。对器件的测试结果与设计数据一致。     

Ni-B非晶态合金催化剂用于卤代硝基苯液相加氢制卤代苯胺

 用化学还原法制备了Ni-B非晶态合金催化剂,并将其用于4种卤代硝基苯的液相加氢反应. 采用X射线衍射和透射电子显微镜研究了催化剂的非晶性质. 在373 K下处理2 h后催化剂保持非晶态结构,在773 K下处理2 h后催化剂完全晶化. 讨论了Ni-B非晶态合金催化剂的催化性能与其结构之间的关系,并与其它Ni基催化剂进行了比较. Ni-B非晶态合金催化剂不仅具有较高的催化活性,而且对卤代芳胺的选择性较高,脱卤率小于4%,优于其它Ni基催化剂.     

离子液体顶空液相微萃取富集苯系物

以水不互溶的离子液体1-丁基-3-甲基咪唑的六氟磷酸盐作为顶空液相微萃取的萃取剂,能够从水溶液中有效地萃取苯系物。当萃取时间为30min时,富集倍数在19～50之间。     

Yb3+:Er3+共掺氟磷酸盐玻璃的发光和激光性能

稀土掺杂氟磷酸盐玻璃是可以满足波分复用系统及超短脉冲系统对带宽和平坦增益要求的激光材料之一。研究了其中一种增益带宽宽,发光谱线平坦的镱铒共掺氟磷酸盐玻璃,其计算半峰全宽为51nm。对反映宽带性能的有效增益截面的研究表明,该镱铒共掺氟磷酸盐玻璃在1530～1580nm之间有一平坦的有效增益截面谱线,证明其宽带特性明显优于掺铒磷酸盐玻璃。对Yb^3 离子敏化效率的研究显示,在镱铒比为10：1时,Er^3 离子的吸收截面和发射截面达最大值,分别为0．6601pm^2和0．7325pm^2,表明此比值下Yb^3 对Er^3 的能量传递效率最高。实验结果显示Yb：Er氟磷酸盐玻璃可用作带宽宽,增益平坦,可实现高能输出的激光器和光纤放大器的基质玻璃材料。     

Reversible Resistance Switching Effect in Amorphous Ge1Sb4Te7 Thin Films without Phase Transformation

We demonstrate a reversible resistance switching effect that does not rely on amorphous-crystalline phase transformation in a nanoscale capacitor-like cell using Ge1Sb4Te7 films as the working material. The polarity and amplitude of the applied electric voltage switches the cell resistance between low- and high-resistance states, as revealed in the current-voltage characteristics of the film by conductive atomic force microscopy （CAFM）. This reversible SET/RESET switching effect is induced by voltage pulses and their polarity. The change of electrical resistance due to the switching effect is approximately two orders of magnitude.     

Preparation and Thermal Characterization of Diamond-Like Carbon Films

Diamond-like carbon （DLC） films are prepared on silicon substrates by microwave electron cyclotron resonance plasma enhanced chemical vapor deposition. Raman spectroscopy indicates that the films have an amorphous structure and typical characteristics. The topographies of the films are presented by AFM images. Effective thermal conductivities of the films are measured using a nanosecond pulsed photothermal reflectance method. The results show that thermal conductivity is dominated by the microstructure of the films.     

Laser Characteristics of Cladding-Pumped Short Er^3＋/yb^3＋ Codoped Single Mode Phosphate Glass Fibre

We experimentally investigate the laser characteristics of a series of short pieces of newly-developed Er^3＋/ Yb^3＋ codoped single mode phosphate glass fibres via the cladding pump of a 976nm multimode laser diode. A stable continuous-wave single transverse mode laser with over 85 m W at 1553nm is generated from a 5.5-em-long active fibre. Single mode laser output power per unit length is up to 15 mW/cm. Moreover, the slope efficiency is 11.8% when the pump power is below 940mW and the 3dB linewidth is 0.06nm at the maximum pump power. The numerical simulation results show that the laser emission slope efficiency can exceed 20% by means of increasing the coupling efficiency of the pump to the fibre core further.     

预处理对垃圾焚烧飞灰玻璃化的影响

在垃圾焚烧飞灰进行熔融玻璃化之前,先用磷酸盐或绿矾溶液对飞灰进行洗涤,研究这种化学稳定化预处理对飞灰玻璃固化效果的影响。结果表明当使用磷酸盐溶液或磷酸盐与绿矾(FeSO4·7H2O)溶液一起对飞灰进行预处理、并且磷酸盐用量达2g磷/kg干灰时,对飞灰的熔融玻璃化有良好的促进效果,经过预处理后的飞灰通过玻璃化过程可实现对所检测的Pb、Hg、As、Cd、Cr五种重金属的全部稳定化,并且在熔融过程中烟尘的产生和重金属的挥发得到有效抑制。