1.30μmDFB激光器组件的设计和制做及其工作原理

本文自行设计和制作了１．３０μｍＤＦＢ激光器组件的讨论了光隔离和光耦合原理。由于采用的激光器－光隔离器－光纤的一体化结构，大大增加了该组件的可用性。在实验中得到高达５５％的耦合效率。     

光缆氢损探讨

本文针对曾困扰光缆领域的氢损问题，通过实验分析，阐明了检验光缆氢损的方法，探讨了产生氢损的主要根源，提出了避免光缆产生氢损的方法及氢损光缆的恢复办法。     

The microwave radiometer aboard ERS-1. II. Validation of thegeophysical products

For pt.I see ibid., vol.31, no.6, p.1186-98 (1993). The ERS-1 microwave radiometer was designed to correct the satellite altimeter data for the excess path delay due to tropospheric humidity. The brightness temperature calibration was tested using two radiative transfer models, applied to the same coincident meteorological profiles over ocean. Differences were analyzed by similarly comparing calculated brightness temperatures with SSM/I data, for the same meteorological data set, extracted from ECMWF (European Center for Medium range Weather Forecasting) analyses. The calibration of the two channels of the ERS-1 microwave radiometer required correction of a few Kelvin. The final water vapor and altimeter path delay validation was performed by comparing routine radiosonde measurements with the retrieved water vapor and altimeter path corrections over a one-year period     

Experimental studies of bistatic scattering from two-dimensionalconducting random rough surfaces

Despite the recent development of analytical and numerical techniques for problems of scattering from two-dimensional rough surfaces, very few experimental studies were available for verification. The authors present the results of millimeter-wave experiments on scattering from two-dimensional conducting random rough surfaces with Gaussian surface roughness statistics. Machine-fabricated rough surfaces with controlled roughness statistics were examined. Special attention was paid to surfaces with large rms slopes (ranging from 0.35 to 1.00) for which enhanced backscattering is expected to take place. Experimentally, such enhancement was indeed observed in both the copolarized and cross-polarized returns. In addition, it was noticed that at moderate angles of incidence, the scattering profile as a function of observation angle is fairly independent of the incident polarization and operating frequency. This independence justifies the use of the geometric optics approximation embodied in the Kirchhoff formulation for surfaces with large surface radius of curvature. When compared with the experimental data, this analytical technique demonstrates good agreement with the experimental data     

Low cost surface passivation for p-type mc-Si based on pseudobinary alloys (Al2O3)x(TiO2)1−x

The conventional process for back side passivation with full face Al screen printing layer is not suitable for very thin multicrystalline (mc-Si) solar cells and approaches to new technological processes are searched for. More investigations have been concentrated on local aluminum contacts and passivation coatings with different layers on mc-Si wafers. The aim of this work is to prove that (Al₂O₃)_x(TiO₂)_1−x is one promising candidate to be applied as passivation layer on multicrystalline Si. Investigations were performed on dielectric films of pseudobinary alloy (PBA) (Al₂O₃)_x(TiO₂)_1−x, prepared by chemical solution deposition known initially as sol–gel method. It was determined that their optical, dielectric and electrophysical properties are suitable for applications of these layers as back side surface passivation for thin multicrystalline silicon cells.     

上海建设节约型城市的战略部署和行动举措

进入新世纪,上海正以建设国际经济、金融、贸易、航运中心之一和现代化国际大都市为目标,加快发展步伐。上海面临着前所未遇的发展机遇,又面临着资源环境等种种严峻的挑战。上海必须妥善处理经济社会和资源环境的关系,大力开展全社会、全方位、全体市民参与的节约行动,努力把上海建设成为国内领先、具有国际水准的节约型城市。     

Processing step-related upgrading of silicon-based solar cells detected by photoluminescence spectroscopy

The aim of this work was to study the effect of solar cell processing steps on the electrical quality of the material, using photoluminescence spectroscopy as a non-contact technique. It was confirmed that consecutive steps in solar cell processing not only lead to electronic quality upgrading in Ribbon and multicrystalline silicon wafers, but also to the introduction of recombining defects. Furthermore, the importance and usefulness of photoluminescence technique on the overall improvement of the substrate material is discussed.     

Impurity local phonon nonradiative quenching of Yb3+fluorescence in ytterbium-doped silicate glasses

We have studied the concentration quenching of Yb³⁺ ion fluorescence in Yb-doped silicate glasses containing up to 3.4×10 ²¹ cm^-3 Yb³⁺ ions. The absorption and fluorescence spectra are similar to those obtained for the Yb³⁺ ion in many different matrices, with a radiative lifetime of approximately 1400 μs. The fluorescence decay curves were different among samples, with strong dependence on the Yb concentration. The decay curves could always be resolved into two exponential components, indicating that the ions reside in two different sites, each of a different characteristic nonradiative decay mechanism. The fast decay times ranged between 6 and 300 μs, and the slow ones ranged between 190 and 1250 μs in different samples. The sites where ions exhibit the fast decay most probably consist of pairs of Yb³⁺ ions. The nonradiative decay probabilities for each site mere directly proportional to the Yb³⁺ concentration in the same site. We propose that the fluorescence quenching occurs by multiphonon nonradiative transitions involving polar local phonon bands created by the presence of the Yb³⁺ ion     

多棱镜扫描分光多头激光毛化圆形毛化点分析

为了得到圆形的毛化点以改善传统单头激光毛化技术椭圆毛化点对轧制钢板的均匀性和力学性能的影响,提出了一种采用多棱镜扫描分光技术的多头激光毛化设备.在一定离焦量下,使得扫描过程中扫描光束所带来聚焦点非均匀移动可以与轧辊同步运行,理论上可以获得椭圆度(长短轴比)最小为1.0010957的近似圆形毛化点,并进行了生产实践.结果表明,理论分析计算与实际结果较为符合.通过对离焦量、扫描速度等毛化参量的控制,可以获得椭圆度根据特殊要求任意调整的毛化点,这为多头激光毛化技术的应用提供了指导.