Improvement of RCA transistor using RTA annealing after theformation of interfacial oxide

A polysilicon emitter RCA transistor (an ultra-thin interfacial oxide layer exists between polysilicon and silicon emitter) is presented which can operate at 77 K for the first time. An ultra-thin (1.5 nm) interfacial oxide layer is grown deliberately between polysilicon and silicon emitter using RCA oxidation and excellent device stability is obtained after rapid thermal annealing (RTA) treatment in nitrogen atmosphere. The RCA transistor exhibits good electrical performance at very low temperature for an emitter area of 3 × 8 μm². The maximum toggle frequency of a 1:2 static divider is 1.2 GHz and 732 MHz at 300 K and 77 K, respectively     

Top-Seeded Melt-Growth of YBa2Cus3Ox Crystals for Neutron Diffraction Studies

We have grown cubic centimeter-size crystals of YBa₂Cu₃O _x suitable for neutron studies, by a top-seeded melt-growth technique. Growth conditions were optimized with an eye toward maximizing phase purity. It was found that the addition of 2% Y₂BaCuO₅ and 0.5% Pt (by mass) were required to prevent melt loss and to obtain the highest crystallinity. A neutron diffraction study on a mosaic of six such crystals found that the final Y₂BaCuO₅ concentration was 5%, while other impurity phases comprised less than 1% by volume. The oxygen content was set to x = 6.5, the crystals were detwinned, and then carefully annealed to give the well-ordered ortho-II phase. The neutron study determined that 70% of the mosaic's volume was in the majority orthorhomic domain. The neutron (006) and (110) rocking curve widths were ～1° per crystal and ～2.2° for the mosaic, and the oxygen chain correlation lengths were >100 Å in the a- and b-directions and ～50 Å in the c-direction.     

I/OIMAGESYSTEM微波中继应用

微波中继的应用非常广泛 ,目前在二维、三维施工中跨越障碍物时 ,一般都使用微波中继站来传输命令和数据。文章就微波中继及I/OIMAGESYSTEM“蛇形排列”先进功能的实际应用进行了详细的阐述 ,同时提出了使用微波中继站应注意的问题。     

永定新河治理工程几个关键问题的研究

永定新河是天津市防洪的北部防线。由于受海相来沙淤积 ,河道行洪能力大幅度下降。针对永定新河治理工程设计中涉及到的河道淤积治理方案、闸位比选、防潮闸结构型式及施工方法、闸下减淤清淤措施等诸多问题进行了分析和研究 ,提出了相应的措施和建议     

Parameters evaluation of SOLA algorithm for time scale modification

Successful operation of the Synchronous Overlap and Add (SOLA) algorithm for Time Scale Modification (TSM) of speech is closely tied to the proper choice of parameters. This paper investigates the quality of time scale modified speech under different values of primary parameters. Based on Mean Opinion Score (MOS) tests and Bark Spectral Distortion (BSD) measure, the proper choices of synthesis shift (Ss) and the duration of the shift search interval (K _max?) are given experimentally. The conclusions can be helpful for operating the SOLA algorithm for time scale modification of speech.     

两段式热脱焦油煤气炉在环形加热炉上的开发应用

介绍了两段式煤气发生炉热脱焦油煤气在无缝钢管环形加热炉上的开发与应用 ,以及两段式煤气发生炉热脱焦油煤气站的设计和采用热脱焦油煤气代替重油所产生的经济效益     

Determination of molecular weight distributions of tert-octylphenol ethoxylate surfactant polymers by laser desorption Fourier transform ion cyclotron resonance mass spectrometry and high-performance liquid chromatography

Triton polymers are commercial surfactants whose molecular weight distributions are conventionally determined by means of high-performance liquid chromatography (HPLC). However, in the case of the important octylphenol ethoxylates [p-C8H17-C6H4-O-(CH2CH2O)n-H], HPLC cannot resolve individual oligomers of high molecular weight Triton surfactants (e.g., greater than 2000 u or so; u = unified atomic mass unit). In this paper, we show that laser desorption Fourier transform ion cyclotron resonance mass spectrometry (LD/FT/ICR/MS) provides a simple and accurate measure of such Triton surfactant molecular weight distributions up to at least 3500 u, based on a single-shot laser pulse measurement of a few seconds duration. Comparison of LD/FT/ICR/MS and HPLC molecular weight distributions of low molecular weight surfactants shows that laser desorption/ionization produces minimal fragmentation and thus offers an accurate measure of the relative abundances of the neutral oligomers, without the need for prior chromatographic separation of the components. Moreover, for all Triton polymer molecular weight distributions (700-3000 u), LD/FT/ICR/MS provides much more highly resolved profiles of oligomer relative abundances. Finally, LD/FT/ICR/MS reveals the presence of poly(ethylene oxide) side products of the polymerization process, which are not observed by HPLC with conventional ultraviolet absorption detection.     

锂离子电池有机电解液成膜添加剂的研究现状

文章综述了锂离子电池有机电解液成膜添加剂的作用原理，具体介绍了CO2、SO2、VC化合物、卤化物、有机铜盐以及马来酐等添加剂的研究现状。     

上海外环隧道水下最终接头的施工技术

沉管隧道采用水下最终接头,可以大大缩短工期和减少成本,但施工难度较大,而且有一定风险。文章以上海外环隧道工程为例,对沉管隧道水下最终接头的施工工艺中管段轴线精度控制、安装保护罩、间隙间的安全排水和混凝土施工等四大难点进行探讨,并介绍了水密性施工和管内结构施工的具体工艺和步骤。指出其成果对今后类似工程具有较大的参考价值。