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31.
Further expansion of optical communication systems depends strongly on the development of cheap component technologies for
functions such as switching, demultiplexing and amplification. Silica-on-silicon is increasingly recognised as the best approach
to low cost integrated optics for such applications, but so far the functionality is limited. The purpose of NODES, a basic
research collaboration sponsored by the European Union under the programme ESPRIT, has been to examine the application of
sol-gel to a highly functional silica-on-silicon technology. In particular, the project has investigated film processing and
characterisation, rare-earth doping for amplification, and semiconductor nanocrystallite doping for nonlinear functions. This
paper presents the background and context to this work, summarises the technical results obtained, and discusses requirements
and challenges for successful application of sol-gel in photonics. 相似文献
32.
33.
稀土萃取分离过程自动控制研究现状及发展趋势 总被引:9,自引:2,他引:9
在简要描述稀土萃取分离生产过程的基础上,综述了目前国内外稀土萃取分离过程中稀土元素成分在线检测的方法、装置及其应用现状;稀土串级萃取分离生产过程的计算机流程模拟以及稀土萃取生产过程的自动控制方法、技术及其应用现状.指出了稀土元素组分含量的软测量方法,以综合生产指标为目标的稀土萃取分离生产过程优化控制方法以及由生产过程管理系统和过程控制系统两层结构组成的稀土萃取分离生产过程综合自动化系统已成为稀土萃取分离生产过程自动化未来发展的方向. 相似文献
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35.
阴离子交换色谱-积分脉冲安培法测定鱼粉和玉米粉水解液中氨基酸 总被引:4,自引:0,他引:4
将高效阴离子交换色谱.积分脉冲安培直接检测法应用于鱼粉和玉米粉水解液中的氨基酸的分析测定。该方法使用Dionex AminoPac PA10阴离子交换柱为分析柱,控制柱温为35℃,以NaOH和NaAc的强碱性溶液为淋洗液,在合适的梯度条件下,可以实现对17种常见氨基酸的高效分离。在强碱性条件下,获得良好分离的各个氨基酸可在配有金工作电极的电化学检测器上以积分脉冲安培法获得高灵敏度的检测。在优化的测定条件下,该方法对这17种氨基酸的检出限在0.21—3.38pmol之间;峰面积校正曲线的线性范围为2—3个数量级;5次平行测定的峰面积的相对标准偏差RSD在0.32%—4.7%之间。该方法应用于玉米粉和鱼粉水解液中氨基酸含量的测定,结果良好。对玉米粉和鱼粉水解液标准加入的回收率分别在81.9%—108.0%和90.0%~108.0%之间。 相似文献
36.
生物柴油作为可再生的清洁能源,已在美国、欧盟等多个国家和地区推行使用.在生物柴油的生产过程中,最高可得到约10%的副产物甘油,副产物甘油的去向将成为生物柴油大规模产业化发展所面临的严峻问题.1,3-丙二醇是一种重要的化工原料,作为合成新型聚酯PTT的原料,1,3-丙二醇已引起人们的广泛关注.以生物柴油副产物甘油为原料耦合生产1,3-丙二醇,不仅解决了生物柴油副产物甘油的出路问题,同时降低了1,3-丙二醇的生产成本.本文详细介绍了生物柴油及1,3-丙二醇生产技术及联产工艺的研究进展,并对其应用前景进行了展望. 相似文献
37.
《Biomedical chromatography : BMC》2018,32(5)
A high‐performance liquid chromatographic (HPLC) method with integrated solid‐phase extraction for the determination of 1‐hydroxypyrene and 1‐, 2‐, 3‐, 4‐ and 9‐hydroxyphenanthrene in urine was developed and validated. After enzymatic treatment and centrifugation of 500 μL urine, 100 μL of the sample was directly injected into the HPLC system. Integrated solid‐phase extraction was performed on a selective, copper phthalocyanine modified packing material. Subsequent chromatographic separation was achieved on a pentafluorophenyl core–shell column using a methanol gradient. For quantification, time‐programmed fluorescence detection was used. Matrix‐dependent recoveries were between 94.8 and 102.4%, repeatability and reproducibility ranged from 2.2 to 17.9% and detection limits lay between 2.6 and 13.6 ng/L urine. A set of 16 samples from normally exposed adults was analyzed using this HPLC‐fluorescence detection method. Results were comparable with those reported in other studies. The chromatographic separation of the method was transferred to an ultra‐high‐performance liquid chromatography pentafluorophenyl core–shell column and coupled to a high‐resolution time‐of‐flight mass spectrometer (HR‐TOF‐MS). The resulting method was used to demonstrate the applicability of LC‐HR‐TOF‐MS for simultaneous target and suspect screening of monohydroxylated polycyclic aromatic hydrocarbons in extracts of urine and particulate matter. 相似文献
38.
The contribution refers to the temperature dependence of IR-absorption spectra (NH4)2AF6 (A - Si and Ge). It is found that with temperature decreasing, the integrated intensities of the bands corresponding to anion fundamentals, increase, while those of cation, decrease. An explanation is given to the phenomena detected, which is based on variations in the strength of the outer-sphere interaction with the temperature, and subsequent redistribution of electron density. 相似文献
39.
M.A. Shams El-Din M. KoerdtC. Wochnowski F. VollertsenA.M. Sadik 《Optics and Lasers in Engineering》2012,50(3):405-412
Polymeric integrated-optical waveguides are prepared in a planar polymer chip by UV-laser lithographic methods. The waveguide samples are irradiated by an excimer laser at a wavelength Λ=248 nm with various irradiation parameters (different fluencies and irradiation doses). Mach-Zehnder interferometer is employed and the refractive index depth profiles of the waveguide samples are obtained. This profile covers two regions having exponential and Gaussian shapes. The model field distributions strongly depend on the refractive index of each region. The mode field distribution and the effective mode indices for each region have been calculated on the basis of a theoretical model and the experimentally measured data. 相似文献
40.