阿斯旺大坝的泥沙效应及启示

阿斯旺大坝修建已经30多年了。本文着重介绍阿斯旺大坝带来的库区泥沙淤积，下辨河道演变和河口海岸的变化，以及采取的治理措施。结合我国大型水利工程建设，阐述阿斯旺大埂给我们的启示。     

用作EDFA光泵浦的激光二极管

近几年来,用作掺铒光纤放大器(EDFA)泵浦光源的半导体激光器,获得了积极的开发和使用。1.48μm 波长大功率激光二极管已商品化,并向更高水平发展。0.98μm 的应变量子阱结构器件也处在开发中,已有部分试用样品。文中介绍1.48μm 和0.98μm 波长大功率半导体激光器的主要结构和开发现状。     

5000t/d水泥生产线窑尾高温风机变频改造

本文主要介绍了高压变频器在淄博鲁中水泥有限公司窑尾高温风机上的应用情况,并对节能效果进行了分析。     

High Altitude Platform Station (HAPS): A Review of New Infrastructure Development for Future Wireless Communications

This paper looks into the relatively new field of high altitude platform stations. HAPS is seen as a ‘middle ground’ between the terrestrial and satellite cases, and aims to exploit of the advantages of both types of system. Since HAPS is such a new field, this paper focuses on the technology behind a HAPS communications system, how this has developed, and compares it to the terrestrial and satellite equivalents. One important area that is being investigated is the applications for which HAPS should be used. This is a critical issue if a significant business case is to be made for HAPS. Worldwide HAPS projects and research issues are also highlighted. Finally, the review concludes with the remarks on the future of HAPS for wireless communications systems.     

无铅焊接高温对元器件可靠性的影响

介绍无铅工艺焊接高温对元器件可靠性的影响,指出了无铅焊接高温对元器件耐温的挑战,介绍了IPC新标准的无铅器件耐温要求,分析了无铅焊接高温带来的元器件失效问题,如"爆米花"、分层、裂纹等,以及焊接高温对器件内部连接的影响,讨论了通过实施元件热管理来解决无铅焊接高温中的热损伤与热失效的方法,对在无铅焊接工艺过程提高元器件的可靠性应用具有一定的指导意义.     

Key technology of D-InSAR at X-band for monitoring land subsidence in mining area and its application

In theory, land subsidence measurement results with high accuracy can be obtained by using the Differential Interferometry Synthetic Aperture Radar （D-InSAR） at X-band. In practice, however, the measuring accuracy of D-InSAR at X-band has been seriously affected by some factors, e.g., decorrelation and high deformation gradient. In this work, the monitoring capability of D-InSAR for coal-mining subsidence is evaluated by using SAR data acquired by TerrraSAR-X system. The SAR image registration method for low coherence image pairs, the denoising phase filter for high noise level interferogram and atmospheric effects mitigation method are the key technical aspects which directly influence the measurement results of D-InSAR at X-band. Thus, a robust image registration method, an improved phase filter method and an atmospheric effects mitigation method are proposed in this paper. The proposed image registration method successfully achieves InSAR coregistration, while the amplitude cross-correlation cannot properly coregister low coherence SAR image pairs. Moreover, the time complexity of the proposed image registration method is obviously slighter than that of the Singular Value Decomposition （SVD） method. The comparing experiment results and the unwrapping phase results show that the improved Goldstein filter is more effective than the original Goldstein filter in noise elimination. The atmospheric influence correction experiment results show that the land subsidence areas with atmospheric influence correction are more clarified than that of without at- mospheric influence correction. In summary, the presented methods directly improved the measurement results of D-InSAR at X-band.     

等离子设备加工高厚径比产品工艺研究

文章通过对孔壁平均去钻污量的数据分析,研究了厚径比与孔壁平均去钻污量的规律,初步界定了等离子去钻污加工高厚径比的能力。通过对等离子去钻污均匀性的控制,控制平均去钻污量,从而得到高厚径比产品稳定加工品质。     

Thin RF sputtered and thermal Ta2O5 on Si for high density DRAM application

Tantalum pentoxide thin films on Si prepared by two conventional for modern microelectronics methods (RF sputtering of Ta in Ar + O₂ mixture and thermal oxidation of tantalum layer on Si) have been investigated with respect to their dielectric, structural and electric properties. It has been found that the formation of ultra thin SiO₂ film at the interface with Si, during fabrication implementing the methods used, is unavoidable as both, X-ray photoelectron spectroscopy and electrical measurements, have indicated. The initial films (as-deposited and as-grown) are not perfect and contain suboxides of tantalum and silicon which act as electrical active centers in the form of oxide charges and interface states. Conditions which guarantee obtaining high quality tantalum oxide with dielectric constant of 32–37 and leakage current density less than 10⁻⁷ A/cm² at 1.5 V applied voltage (Ta₂O₅ thickness equivalent to about 3.5 nm of SiO₂) have been established. These specifications make the layers obtained suitable alternative to SiO₂ for high density DRAM application.     

分组无线通信控制器的设计

文章介绍了一种新型的用于组成无线计算机通信网的通信控制器的设计,这种通信控制器具有高速的特点,它可以利用一般的ＵＨＦ,ＶＨＦ通信机通信,组成计算机分组无线网。