十二酰胺丙基二甲基羟乙基氯化铵与十二烷基硫酸钠水溶液的表面吸附和胶束形成

利用十二酰胺丙基二甲胺和氯乙醇反应 ,合成了十二酰胺丙基二甲基羟乙基氯化铵 (DDHA)阳离子表面活性剂 ,将其与十二烷基硫酸钠 (SDS)以不同摩尔比进行混合 ,测定了混合系统的表面张力 ,计算了单一系统和混合系统的饱和吸附量、分子最小截面积 ,表面层和胶束中 DDHA的摩尔分率及分子间相互作用参数 ,目视观察了混合系统的浑浊情况。结果表明 :在降低γcmc和 cmc方面 ,DDHA SDS混合系统有协同效应 ,表面层和胶束的组成与二组分配比有关 ,但是非对称的 ,等物质的量混合物中 ,DDHA在胶束和表面层中具有较大的摩尔分数。DDHA与 SDS在实验测定的各混合系统中都不出现混浊     

The influence of viewing distance on subjective impairment assessment

In this paper, the influence of viewing distance on subjective assessment of the impairment in video sequences is investigated. Subjective tests using the double-stimulus impairment scale variant II (DSIS II) method have been conducted at viewing distances of 5H (where H stands for the screen height) and 3H, respectively. Several statistical measures have been used to analyze the influence, including correlations and ANOVA (analysis of variance) tests. The results reveal that there is a very high correlation between the subjective scores, the variances are similar under the two viewing distances, the means of subjective data at these two viewing distances are the same, and there is no interaction between the viewing distance and the other two factors, i.e., the codec system and the source sequence. Throughout the tests, there is no evidence that a closer viewing distance such as 3H will vary the subjective test result statistically significantly.     

试论电信企业激励机制的改革与创新

本文分析了电信企业面临的社会经济新形势，揭示了在计划经济条件下电信企业内部激励机制存在的弊端，论述了电信企业进行激励机制改革与创新的必要性和必然性，提出了电信企业在生存和发展中改革与创新激励机制的指导思想及原则，提出了如何建立一套科学、合理的激励机制，以便更有效地发挥员工的积极性、主动性和创造性，最大程度地提高激励的效用。     

A new efficient method for one‐pot conversions of aryl carboxylic acids into nitriles without solvent

A new efficient method for synthesising nitriles, important organic reagents, is reported in this paper. In an environmentally benign solvent‐free system, aryl carboxylic acids were converted into the corresponding nitriles via one‐pot reactions, by amidation with ethyl carbamate followed by dehydration with thionyl chloride, in excellent yields. The results showed that the method has the advantages of lower cost, higher yield, less pollution and greater ease of work‐up. Copyright © 2008 Society of Chemical Industry     

大朝山水电站地下洞室安全监测资料分析

大朝山水电站引水发电系统为地下工程，根据各项安全监测物理量的主要观测成果，对最大观测值分析其对工程的安全影响，为保证其安全运行具有重要意义。为此，分别对大朝山水电站的主要地下建筑物，包括压力引水隧洞、地下厂房、尾水调压室的最大观测值进行了分析研究，并提出了一些建议，有较大的参考价值。     

热平衡流量计研究与应用

依据热平衡方法测流量原理研制的热平衡流量计没有任何可动部件，可靠性大大加强，可以代替常用的浮子流量计和涡轮流量计。该仪器的应用为油水井及注聚合物井的流量测试提供了更为有效的手段和方法。