光学课程和高、新科技结合探索

对光学课程教学现代化问题进行了探索和实践,一是光学基本原理与科技前沿典型实例结合,二是从激光新技术讲授光学基本概念,三是从光电技术发展探讨光学课程中的新仪器,新器件。     

Method for clone checking

A new method for simple and fast clone checking is described. We combined the Pyrosequencing technology with a preprogrammed nucleotide dispensation strategy for fast analysis of DNA constructs. To test this method, the N-terminus region of plasmids constructed for the production of recombinant apyrase was analyzed. Of the ten plasmids tested, seven constructs were correct, two constructs showed one base deletion, and one construct showed deletion of a 195 bp fragment. The preprogrammed nucleotide dispensation strategy allowed the identification of the sequence downstream of the deletions. Thus, this method determines both the location and nature of possible artifacts.     

Practical Evaluation of Sol-gel and Hydrothermal Fritting Technologies for Rapid Column Fabrication and its Application in Capillary Electrochromatography and Micro-Liquid Chromatography

Summary Tetraethoxysilane (TEOS) sol-gel technology was investigated as an alternative fritting methodology. It allowed a wide range of silica based stationary phase materials of differing particle sizes (3–12 m) in capillaries of differing lengths (7.4–25 cm) and internal diameters (100–375 m) to be investigated. Experiments comparing coupled with continuous capillaries illustrated a loss of approximately 7% in chromatographic peak efficiency for the coupled capillary format. Continuous column architecture experiments showed that it is possible to detect through the packed bed without losing the peak efficiency when optimised detector settings were employed. TEOS fritting technology was fast and reliable, allowing rapid stationary phase screening for CEC or micro-LC.     

Development and optimization of magnetic technologies based processes for removal of some toxic heavy metals

In the developing countries where the cost is often a decisive factor, extensive studies were undertaken to test the most effective factors on the preparation, optimization and validation of the magnetic particles (or, more accurately, magnetizable particles) for removal of heavy metals from wastewaters. The objective of the proposed work was focused to provide promising solid-phase materials, which, are relatively in expensive and combine high surface capacity with fast efficient treatment. Four various metal oxides including hydrous ferric oxide (HFO), hydrous stannic oxide (HSO) and mixed ferric/stannic oxide (HMO), were prepared by precipitation with ammonia from metal chloride solutions. Two mixed oxides were prepared with different Sn/Fe ratios of 50% and 20%. Optimal conditions for the activation of these particles and the subsequent mixing of various metals oxides are tested together with the utility of the method to get a new composite material with developed chemical characteristics over their individual metal oxides. Factors affecting the sorption behavior of the prepared samples in basic and acid media were elucidated. The magnetic treatment procedure using the mixed oxide (50%) enables the equilibration step to be carried out rapidly mainly due to ferric oxide during the magnetization process and efficiently due to high capacity of the stannic oxide. A key factor in achieving very high uptake percentage is the reduction of non-specific binding of various heavy metals to the solid phase support. This is usually achieved by increasing the ion exchange capability, in addition to their adsorption process.     

The current state of sol-gel technology

The current state of sol-gel technology has been reviewed mainly from the standpoint of microstructures of materials which can be achieved by the sol-gel method. It has been shown that the sol-gel method makes it possible to produce a great variety of high technology materials by providing the existing substances with a significant microstructure and producing the material with a novel microstructure. There are microstructures characterized by micropores, preferential crystal orientation, inorganic-organic and inorganic-inorganic composites of hybrid nature and gradient composition. These characteristic microstructures are related to the properties and applications of the materials.     

First preparation of nanocrystalline zinc silicate by chemical vapor synthesis using an organometallic single-source precursor

A method is presented to prepare nanocrystalline alpha-Zn(2)SiO(4) with the smallest crystal size reported so far for this system. Our approach combines the advantages of organometallic single-source precursor routes with aerosol processing techniques. The chemical design of the precursor enables the preferential formation of pure zinc silicates. Since gas-phase synthesis reduces intermolecular processes, and keeps the particles small, zinc silicate was synthesized from the volatile organometallic precursor [[MeZnOSiMe(3)](4)], possessing a Zn-methyl- and O-silyl-substituted Zn(4)O(4)-heterocubane framework (cubane), under oxidizing conditions, using the chemical vapor synthesis (CVS) method. The products obtained under different process conditions and their structural evolution after sintering were investigated by using various analytical techniques (powder X-ray diffraction, transmission electron microscopy, EDX analysis, solid-state NMR, IR, Raman, and UV/Vis spectroscopy). The deposited aerosol obtained first (processing temperature 750 degrees C) was amorphous, and contained agglomerates with primary particles of 12 nm in size. These primary particles can be described by a [Zn-O-Si] phase without long-range order. The deposit obtained at 900 degrees C contained particles with embedded nanocrystallites (3-5 nm) of beta-Zn(2)SiO(4), Zn(1.7)SiO(4), and ZnO in an amorphous matrix. On further ageing, the as-deposited particles obtained at 900 degrees C form alpha-Zn(2)SiO(4) imbedded in amorphous SiO(2). The crystallite sizes and primary particle sizes in the formed alpha-Zn(2)SiO(4) were found to be below approximately 50 nm and mainly spherical in morphology. A gas-phase mechanism for the particle formation is proposed. In addition, the solid-state reactions of the same precursor were studied in detail to investigate the fundamental differences between a gas-phase and a solid-state synthesis route.     

Multianalyte Biosensors for the Simultaneous Determination of Glucose and Galactose Based on Thin Film Electrodes

A multianalyte biosensor for the simultaneous determination of glucose and galactose was developed by immobilizing glucose oxidase (GOD) and galactose oxidase (GAO) on Nation-modified thin film platinum disk electrodes. The dual Pt working electrodes with disk shape and the surrounding ring shaped counter electrode were fabricated by thin film technology,which were integrated onto the same microchip. The response of the designed biosensor for glucose and galactose were linear up to 6.0mmol/L and 3.5mmol/L with sensitivities of 0.3μA/mmol/L and 0.12μA/mmol/L, respectively. No cross-talking effect was observed.     

SYNTHESIS AND CHARACTERIZATION OF NOVEL SOL-GEL DOPED ORGANIC／INORGANIC HYBRID NONLINEAR OPTICAL MATERIALS

4-hydroxy-4 ‘-nitro azobenzene (NHA) and 4-amino-4 ‘-nitro azobenzene (DO3) were prepared respectively from p-nitrophenylamine as a precursor compound. Two kinds of doped organic/inorganic hybrid nonlinear optical (NLO) materials containing NHA and DO3 were synthesized by Sol-Gel process. The preparation and properties of two NLO materials were studied and characterized by FTIR, IH-NMR, UV-VIS, SEM, DSC and SHG measurements. The results show that the maximum doping amounts of NHA and DO3 in two doped hybrid NLO materials are 7.2(wt)% and ll.3(wt)% respectively, and the corresponding second-order NLO coefficients (d33values) are 2.91 ×l0^-3esu and 6.14×10 -8 esu. Two doped NLO materials have relatively good RT stability, after 90 days at RT the d33 values can maintain about 85% of their initial values, but after l0h at 100℃ can only maintain about 50% of their initial values. In this report, the reasons for high-temperature instability of doped materials were discussed, and the possible improvements were also suggested.     

Solid‐state lasers based on inorganic–organic hybrid materials obtained by combined sol–gel polymer technology

Sol–gel glass matrices in which organic laser dyes are embedded can be used as the gain medium in solid‐state, continuously tunable lasers. Such lasers are very simple to construct, and potentially very compact and efficient. Unlike the commonly used liquid dye laser systems, solid‐state dye lasers can be made mechanically robust and portable. In this article, the development of sol–gel/dye lasers, including the sol–gel technology, dye properties, and laser operation, is reviewed. In addition, new solid‐state hosts (such as polyurethane/silica ORMOSILs), additional organic dyes (cyanines), and new studies on the stability of the dyes are presented. Copyright © 2004 John Wiley & Sons, Ltd.     

Preparation and investigation of polymethylphenylvinylsiloxane-coated solid-phase microextraction fibers using sol-gel technology

Summary Poly(methylphenylvinylsiloxane) (PMPVS) coating was first prepared using sol-gel technology and applied for solid-phase microextraction (SPME). The extraction properties of the novel coating for volatile and semi-volatile organic compounds were investigated using a homemade SPME device coupled with GC-FID. The porous surface structure of the coating provided high surface area and allowed for high extraction efficiency. Compared with commercial SPME stationary phase, the new phase showed better selectivity and sensitivity toward the various analytes, due to their inherent multifunctional properties and the features of sol-gel chemistry. Furthermore, PMPVS coating showed good thermal stability and long lifetime.