稀土铈（Ⅳ）离子和钼酸钠在盐酸溶液中对冷轧钢的缓蚀协同效应

用失重法和电化学法研究了盐酸介质中，稀土铈(Ⅳ)离子和钼酸钠对冷轧钢的缓蚀协同效应．研究结果表明，钼酸钠和稀土Ce^4 对冷轧钢都有一定的缓蚀作用，但最大缓蚀率不超过42％．通过吸附模型的讨论发现，在Langmuir吸附模型的基础上进行校正后的模型能更合理地解释实验结果，并求出了三个吸附参数(△H^-，ΔG^-，△S^-)．通过对比实验，发现稀土铈(Ⅳ)离子和钼酸钠对冷轧钢产生了明显的缓蚀协同效应，最大缓蚀率可达90％左右。     

Pd-Si Binary Bulk Metallic Glass Prepared at Low Cooling Rate

We report that binary bulk metallic glasses can be made up to 6ram in diameter in a Pd Si ahoy system by air cooling at slow cooling rate (about 8 K/s). The high stability of the undercooled liquid and the large glass-forming ability (GFA) of the binary alloy are contributed to the removing of heterogeneous impurities in the alloy melt by employing the fluxing technique. It has been found that decreasing cooling rate can increase the supercooled liquid region and thermal stability of the glassy alloy. After fluxing, a wider supercooled liquid region (△T = 58 K) and higher glass-forming ability have been obtained in a Pd81Si19 binary glassy alloy prepared by slow cooling rate.     

3G移动通信系统中的新型宽带语音编码VMR-WB

本文介绍了一种将应用于第三代移动通信的新型语音声码器-变速率多模式宽带(VMR-WB)声码器。VMRWB 专为CDMA2000标准设计,有效语音带宽扩展为:50 Hz=7000 Hz,有四种不同速率的运行模式,每一种模式对应一定质量的平均数据速率。在相同的速率下,VMR-WB语音声码器的主观质量和性能较现有的窄带和宽带编码标准都有明显的提高。本文主要介绍其编码原理以及一些特性。     

Thermal Conductivity of Ce Doped Bi-2212 Superconductors

The temperature dependence of the thermal conductivity in Bi2Sr2 Ca1-xCexCu2Oy x = 0.1, 0.2, 0.3, 0.4 is presented. With increasing Ce-doping level, the thermal conductivity peak under Tc is suppressed then disappears,while another peak appears at low temperatures for the non-superconducting compounds. The numerical analysis shows that the thermal conductivity peak under Tc can be well described by the normal electron relaxation-time contribution model, and the phonon-induced thermal conductivity peak could be well described within the Debye approximation of the phonon spectrum. The existence and velriation of these two thermal conductivity peaks indicate the adjustability between the superconducting and insulating components in the samples with different Ce-doping levels.     

氧乙炔焰线烧蚀率测定不确定度的评定

就氧乙炔焰线烧蚀率测定不确定度的评定进行探讨 ,以期提高我们的测试水平。实验按GJB 32 3- 87“氧 -乙炔烧蚀实验方法”进行。     

声学国家标准介绍(Ⅵ)

本规范是为防止工业企业噪声的危害，保障职工的安全、健康和正常工作，保护环境，促进工业生产、建设的发展而制定的，适用于工业企业中新建、改建、扩     

关于压缩空气分散供应的探讨

对实行压缩空气分散供应有利于节能降耗的探讨。     

年龄结构胎次人口递进模型及其解的性质

本文建立了年龄结构胎次人口递进模型,研究了模型解的性质,揭示了总和生育率与胎次递进率之间的定量联系,深入讨论了胎次递进率影响人口发展过程的机制。     

球形触点阵列与四边扁平封装的比较

球形触点阵列（ＢＧＡ）封装技术作为一种新的封装技术越来越受到人们的重视。从安装率和成本、表面安装印制板设计以及焊点可靠性三个方面对球形触点阵列与四边扁平封装（ＱＦＰ）进行了比较。分析认为，ＢＧＡ和ＱＦＰ各有其优势和劣势，各有其应用重点。