Depth profiles of Ag nanoparticles in silicate glass

Silver nanoparticle composite glass has been synthesized by ion exchange and a subsequent thermal treatment method. Transmission electron microscopy (TEM) and ultraviolet-visible spectrometry were used to study the depth profiles of Ag nanoparticles in silicate glass. Results indicate that Ag nanoparticles are nearly spherical in shape with a single-crystalline structure. Also, the volume fraction of Ag nanoparticles is very high in the surface layer of 5 μm, and then decreases slowly across the depth of 30 μm, thereafter the volume fraction reduces quickly to zero at the depth of 100 μm. The plasmon resonance bi-absorptions in the surface layer of the annealed specimen at 600 °C can be attributed to bi-modal distributions of Ag nanoparticles in the layer. The bi-modal distributions can be explained by the Ostwald ripening theory. PACS 81.05.Pj; 81.07.-b; 68.37.Lp     

Organic thin-film transistors with polymeric gate insulators

Copper phthalocyanine (CuPc) thin-film transistors (TFTs) have been fabricated using spin-coated polymeric gate insulators, including polymethyl methacrylate (PMMA) and a novel poly(methylmethacrylate-co-glycidylmethacrylate) (P(MMA-co-GMA)). These devices behaved fairly well and showed satisfactory p-type electrical characteristics. The transistor with P(MMA-co-GMA) gate insulator showed higher field-effect mobility, μ_FET = 1.22 × 10⁻² cm²/V s, larger on/off current ratio, I_on/I_off = 7 × 10³ and lower threshold voltage, V_T = −8 V, compared with the transistor with PMMA gate insulator (μ_FET = 5.89 × 10⁻³ cm²/V s, I_on/I_off = 2 × 10³ and V_T = −15 V). The higher mobility of CuPc on P(MMA-co-GMA) was attributed to better ordering and enhanced crystallinity within the CuPc film and the better CuPc/P(MMA-co-GMA) interface, as observed by X-ray diffraction (XRD), atomic force microscopy (AFM) and scanning electron microscopy (SEM) measurements. The correlation between the structural properties and the device performance of CuPc films grown on different polymeric gate insulators is discussed.     

投影显示亮度均匀性稳健校正方法

随着投影仪的发展,其显示质量越来越受到人们关注.投影显示中普遍存在亮度不均匀性问题,且大部分高灰度图像在亮度校正后易出现饱和.而一般的剪切法会极大地降低像面均匀性.为解决这个问题,基于投影仪相机系统建立系统光度学模型,在传统线性映射方法的基础上提出了一种亮度不均匀性校正的非线性稳定算法.实验表明,采用的投影仪在校正前其图像显示亮度从中心到边缘下降了近50%,像面不均匀性的相对均方根误差(RRMS)为17.7%;而饱和图像校正后像面的RRMS为1.69%,几乎达到了与未饱和图像(1.55%)相同的校正精度,同时基本保持了显示图像的平均亮度水平.     

Real-time spectral imaging in three spatial dimensions

We report what is to our knowledge the first volume-holographic optical imaging instrument with the capability to return three-dimensional spatial as well as spectral information about semitranslucent microscopic objects in a single measurement. The four-dimensional volume-holographic microscope is characterized theoretically and experimentally by use of fluorescent microspheres as objects.     

ESR研究非晶Ag+导体的晶化

用电子自旋共振(ESR)方法对非晶Ag⁺离子导体0.85AgI~0.15Ag₄P₂O₇的热处理晶化过程进行研究,在样品中掺入微量(约1×10^-3 g/g)的Mn²⁺或V⁴⁺离子作为自旋探针离子,它们的ESR谱强度随升温线性减弱,当样品完全晶化时ESR谱消失。这样测定的样品完全晶化的温度分别为98℃(掺Mn的)和108℃(掺V的).本文还对Mn²⁺和V⁴⁺的ESR谱进行了分析。     

质子激发X光源及其应用

本文介绍了用质子束激发靶元素发射特征线的方法建立的高强度、准单色低能X光源的主要特征、物理性能及其实际应用。当K-400加速器提供的质子流指标为1mA/270keV时,在0.183-3keV之间的9个能点上,其相应源强可达10~(10)-10~(13)个/s数量级,为低能X光诊断技术的发展提供了必要条件。     

Capillary electrochromatographic separation of enantiomers on chemically bonded type of cellulose derivative chiral stationary phases with a positively charged spacer

Positively charged chiral stationary phases (CSPs) were prepared for capillary electrochromatography (CEC) separation of enantiomers by chemically immobilizing cellulose derivatives onto diethylenetriaminopropylated silica (DEAPS) with tolylene-2,4-diisocyanate (TDI) as a spacer reagent. Anodic electroosmotic mobility was observed in both nonaqueous and aqueous mobile phases due to the positively charged amines on the surface of the prepared CSPs. For comparison, the traditionally used 3-aminopropyl silica (APS) was also adopted as the base material instead of DEAPS to prepare CSP. It was observed that the EOF on the DEAPS-based CSP was 18%-60% higher than that on the APS-based CSP under nonaqueous mobile phase conditions. Separation of enantiomers in CEC was performed on the positively charged CSPs with the nonaqueous mobile phases of pure ethanol or mixture of hexane-alcohol and the aqueous phases of acetonitrile-water or 95% ethanol. Fast separation of enantiomers was achieved on the newly prepared CSPs.     

Single crystal growth of copper phthalocyanine using exaltation–evaporation growth method

A new method of growing single crystal for β-form copper phthalocyanine (CuPc) is presented in this paper. Melted anthracene was used as solvent of CuPc. The method, vaporizing the solvent using an automatic exaltation machine, was employed to grow CuPc single crystals. The needle-like single crystals of CuPc up to 11.6 mm in length were obtained by applying this method. The influences of different temperatures, exaltation speeds and concentrations on the single crystals growth were also discussed. The method was called exaltation–evaporation growth method.     

模糊聚类-偏最小二乘光度法同时测定锇和钌

将模糊聚类分析与偏最小二乘相结合，对锇、钌双组份重叠光谱进行解析；较好地解决了校正分析中校准模型的优化问题，提高了分析结果的准确度；研究了锇、钌－ＳｎＣｌ２－乳化剂ＯＰ－阿拉伯树胶（ＡＧ）－丁基罗丹明Ｂ（ＢＲＢ）高灵敏多元离子缔合物显色体系。锇、钌的检出限分别为 ０，６３２ μｇ／Ｌ和 ０．３６８ μｇ／Ｌ，模拟地质样品分析结果的相对误差小于±１０％。     

A polar oxide with a large magnetization synthesized at ambient pressure

The perovskite Bi2Mn4/3Ni2/3O6 is polar and combines relative permittivity behavior consistent with ferroelectricity with the magnetic response of a concentrated spin-glass. Bi2Mn4/3Ni2/3O6 is accessible by ambient pressure synthesis despite the instability of the end-members BiMnO3 and BiNiO3 under these conditions.