CAD8903机芯的视频音频转换电路设计

本文概要介绍了CAD 8903机芯采用国产集成电路CD7680,CD74211,DG4053实现音频、视频切换功能的电路,并对CD7680中音频信号处理电路的特殊用法进行了说明。     

平衡纵剖面数值试验及其对防洪的影响研究

本文采用一维非恒定流非均匀沙的水沙数学模型，以长江中游螺山汉口河段为背景，进行了根化数值模拟试验，分析了该概化河段平衡纵剖面的变化规律及其与上游来水来沙条件的关系，并和相应的理论公式进行了比较。在此基础上，对水沙条件发生较在变化时的平衡纵比降以及带来的对长江中下游防洪的影响进行了分析。     

电解法烟道气二氧化硫在线监测系统的设计

介绍了一种烟道气中SO2在线检测系统，该系统可以实现24h不间断地监测烟道气中SO2的体积分数和质量浓度，同时将信息经网络传送给环保有关部门，具有一定的新颖性、可靠性、准确性。     

Resilient metal spring network silicone-matrix composite for separable interconnections

Resilient metal spring silicone-matrix conducting composites for separable interconnections in electronics were fabricated by the impregnation of silicone into a preform comprising randomly oriented C-shaped Cu-Be springs and a small proportion of Sn-Pb solder, which served to connect the springs at some of their intersections. Composites containing 6.1-9.8 vol.% total filler exhibited volume electrical resistivity 0.5-1.0 mΩ.cm and contact resistivity (with copper) 11-17 mΩ.cm². A compressive stress of about 30 kPa was needed for the low contact resistivity to be reached. The volume 17-26% and the contact resistivity increased by 5% after heating in air at 130-150°C for seven days. Composites containing <9 vol.% total filler showed no stress relaxation for seven days at 6.0% strain.     

蒸发式冷凝在制冷工艺上的应用

分析对比制冷工艺中几种冷凝方式，指出发展蒸发式冷凝技术对制冷系统节能的重要意义；通过分析蒸发式冷凝的换热机理，在试验和实践的基础上讨论了影响蒸发式冷凝器性能的几个重要因素。     

热轧带钢连续冷却过程中相变体积分数的计算

基于相变动力学原理 ,在充分考虑变形对相变影响的情况下研究了奥氏体向铁素体、珠光体和贝氏体相变的动力学。探索了热轧带钢连续冷却过程中相变体积分数的计算方法。用此方法进行的计算机模拟与实验结果相当吻合。     

Phase equilibria of quasi-binary systems consisting of multicomponent polymers 1 and 2. IV: Poly(ethylene oxide)/poly(propylene oxide) systems

To confirm the reliability of the theory of phase equibria of multicomponent polymer 1/multicomponent polymer 2 systems (i.e. quasi-binary systems) and the method of computer experiment based on this theory (Brit. Polym. J., 23 (1990)285; 23 (1990)299; Polym. Int., 29 (1992)219), could point curves (CPC), two-phase volume ratios ( R ) and critical solution points (CSP) have been determined experimentally for the quasi-binary mixtures of poly(ethylene oxide) (M¯_w = 647, M¯_w/M¯_n = 1.15; M¯_w and M¯_n, the weight-average and numberaverage molecular weights, respectively) and poly(propylene oxide) (M¯_w = 2028, M¯_w/M¯_n = 1.08; and M_w = 2987, M_w/M_n = 1.13). The hydroxyl end groups of both polymers were methoxylated in advance by the Cooper & Booth method (Polymer, 18 (1977)164). The thermodynamic interaction parameter between both polymers, χ₁₂, and the concentration dependence parameters for the above quasi-binary systems were determined by the method proposed in a previous paper (Brit. Polym. J., 23 (1990)299). CPC, R and CSP values calculated on the basis of the theory are in good agreement with the values determined experimentally.     

Dough mixing and breadmaking properties of quinoa-wheat flour blends

Flour blends of quinoa-wheat containing 0, 5, 10, 15, and 20% of manually dehulled quinoa meal or flour were evaluated for dough mixing and breadmaking properties and liking of the bread by a small panel. Increasing amounts of quinoa meal or flour increased farinograph absorption and dislike of bread for most of the panel. Dough development time increased with increase in meal but decreased with increase in quinoa flour. At 10% inclusion levels differences in liking from control 100% wheat flour bread were smaller for flour or water extracted meal to most of the panel, than with 10% non-extracted meal. This suggests that 10% inclusion of flour or water extracted meal may have potential for further investigation.     

焦炉装煤烟尘治理的烟气量计算

通过对焦炉装煤烟尘治理的烟气量计算和研究,提出不同治理系统的烟气量计算方法及应采取的措施。