中红外光纤技术用于腮腺肿瘤诊断的研究

采用傅里叶变换红外光谱法与中红外光导纤维联用技术对１１例肿瘤，７例正常腮腺和１例舍格伦综合症的红外光谱进行了对比研究。结果发现正常腮腺和舍格伦综合症的红外光谱很相似，而与肿瘤的光谱存在着明显差别，同时也观察到良性与恶性肿瘤的光谱在若干波段处也有所不同．     

Increase in dynamic modulus of nylon 6 fiber in repeated heating and cooling cycles under sinusoidal deformation

The repeated heating and cooling cycles under sinusoidal deformation have been investigated on nylon 6 fibers. The fibers zone-drawn twice at high temperatures were used, which have a crystallinity of 52.2% and a birefringence of 59.4×10^?3. The heating and cooling cycle was performed twice at a frequency of 110 Hz over a temperature range from 0°C to 180°C and 190°C. The crystallinity and birefringence of the treated fiber were 51.7% and 60.7×10^?3, respectively, indicating almost no changes in molecular orientation and crystallinity. However, the dynamic modulus, E′, increased steadily over whole temperature range measured. Finally, the E′ value reached 21 GPa at room temperature and 10 GPa ever at 180°C. The elongation of fiber after two cycles was only about 5%. © 1993 John Wiley & Sons, Inc.     

Tensile Characterization of FRP Rods for Reinforced Concrete Structures

The application of FRP rods as an internal or external reinforcement in new or damaged concrete structures is based on the development of design equations that take into account the mechanical properties of FRP material systems.The measurement of mechanical characteristics of FRP requires a special anchoring and protocol, since it is well known that these characteristics depend on the direction and content of fibers. In this study, an effective tensile test method is described for the mechanical characterization of FRP rods. Twelve types of glass and carbon FRP specimens with different sizes and surface characteristics were tested to validate the procedure proposed. In all, 79 tensile tests were performed, and the results obtained are discussed in this paper. Recommendations are given for specimen preparation and test setup in order to facilitate the further investigation and standardization of the FRP rods used in civil engineering.     

Elastic modulus of supercooled liquid and hot solid silicon measured by inelastic X-ray scattering

The dynamical structure factors of supercooled-liquid and hot-solid silicon are measured by inelastic X-ray scattering at the same temperature, 1620 K. Two significant changes in the averaged longitudinal sound velocities and in the longitudinal modulus are observed. First, we observe a different longitudinal modulus in the polycrystalline hot-solid silicon compared to the extrapolated value obtained from the single-crystal measurement. This reduction of the modulus may be a precursor of the semiconductor-to-metal transition. Second, the increase in the longitudinal modulus in the liquid upon supercooling is consistent with an increase in the degree of the directional bonding.     

Simulation of Ultrashort Laser Pulse Propagation in Silica Fibre by FDTD+

The finite-difference time-domain algorithm is extended to solving the Maxwell's equations with nonlinear terms which include all exact Sellmeier-fitting values in this paper. The results obtained by the presented method are in good agreement with those from experiments, and this method is even better than solving the generalized nonlinear Schrödinger equation by split-step Fourier method. The spectral phase of propagated pulses is also obtained by the presented method, which is important for investigation of single-cycle optical pulse generation via phase compensation of the nonlinear-chirped in silica fibers.     

Determination of the inelastic mean free paths (IMFPs) in Ti by elastic peak electron spectroscopy (EPES): Effect of impurities and surface excitations

Surface excitations are important in surface sensitive electron spectroscopes, especially in elastic peak electron spectroscopy (EPES) since they may distort quantitative information. This phenomenon is more pronounced at low electron energy and glancing emission angles and should be appropriately corrected.In the present work we investigate quantitatively the role of contaminations, density and surface excitations on electron inelastic mean free paths (IMFPs) in Ti determined by elastic peak electron spectroscopy (EPES) using Cu standard. In the Monte Carlo algorithm the new NIST 3.1 database of electron elastic scattering cross sections was applied. It has been also shown that accounting for surface excitations, as well as for appropriate input parameters (surface composition, density, hydrogen) in the EPES method, is important for accuracy of evaluated IMFPs. Due to high reactivity of Ti, the IMFPs for contaminated Ti may be of interest. The authors indicate the magnitude of various corrections on the IMFPs derived by EPES.     

Dual-order Raman fiber laser with suppressed low-frequency pump-to-stokes RIN transfer

By employing an output-power clamping technique, a dual-order Raman fiber laser (RFL) is theoretically presented with suppressed low-frequency relative-intensity-noise (RIN) transfer from pump sources to both first- and second-order Stokes output. Their powers can be easily tuned in a large dynamic range. Furthermore, the second-order output power can be individually controlled, which makes it flexible to adjust the ratio of the first- to second-order output power. In addition, the stabilization of low-power second-order output is also accomplished in the RFL setup. These properties fit the proposed RFL for use as dual-order pump sources in Raman fiber amplifiers.     

The study of chromatic dispersion and chromatic dispersion slope of WI- and WII-type triple-clad single-mode fibers

In this paper, the chromatic dispersion and chromatic dispersion slope of two kinds of triple-clad single-mode fibers with a depressed index inner cladding named WI- and WII-type were examined. A feasible approach to calculate chromatic dispersion and higher-order dispersion was established successfully, and the influences made by the optical parameters and geometric parameters on the chromatic dispersion coefficient and its slope were analyzed in detail. The calculated results show that the optical parameter R₂, which symbolizes the third cladding effect, has a strong impact on the chromatic dispersion coefficient and the chromatic dispersion slope, and the degrees of such impact are closely related to the other parameters.     

液体成分检测中的光学方法

在生命科学、医药、食品和环境保护等领域经常需要对液体成分进行检测。重点介绍了目前比较新的两种液体检测方法 :毛细管电泳法和液滴分析法。将这两种方法和传统的液体检测方法进行了比较 ,列举了这两种方法的优点和有待解决的问题。同时说明了光学技术在液体成分检测中的应用。结果表明 ,毛细管电泳法和液滴分析法对试样在线抽样检测是一种快速、综合、简单、低成本的检测方法