Derived Lengths of Solvable Groups Having Five Irreducible Character Degrees II

Let G be a solvable group with five character degrees. Suppose that there is some prime p so that G/O ^p (G) is not Abelian. Also, assume that cd(G) contains a degree that is not divisible by p. Under these hypotheses, we show that the derived length of G is at most 4.     

Cyclic cohomology and algebra extensions

We construct a spectral sequence to study cyclic cohomology for an extension A = R/I of algebras. When R is a free algebra we describe the cyclic cohomology of A in terms of traces defined on R or powers of I. Explicit cyclic cocycles representing the cyclic cohomology class belonging to the trace are constructed as analogues of Chern character and Chern-Simons forms.Dedicated to Alexander Grothendieck     

电视节目包装中的文字设计艺术

文字是电视节目包装中的重要元素之一,除了传达信息的基本功能外,经常起到决定整体效果的关键作用。节目包装文字设计应突出本台文化和本土文化,文字的设计必须与节目相匹配,形成统一整体。     

微密封真空微电子二极管

本文介绍了一种微密封真空微电子二极管的工艺及实验结果。     

高性能IGBT模块的设计考虑

本文对ＩＧＢＴ模块中功率芯片（ＩＧＢＴ和续流二极管）的优化设计进行了讨论。通过优化几个重要的工艺参数并改进器件的结构，ＩＧＢＴ不仅有足够的短路容量，而且正向压降与电流下降时间之间可实现最佳折衷。另外，续流二极管的反向恢复特性也有明显改善。通过采用衬底控制技术，ＩＧＢＴ模块的输出特性不受温度的影响，输出电流更稳，输出阻抗更高。本文详细介绍了整个设计考虑。     

使用一个双通道器件的声光相关器及其设计方法

介绍了一种仅使用一个双反向通道式声光器件的声光相关器，从正常布喇格衍射和反常布喇格衍射两方面，讨论了这种器件的设计方法。     

SMD在LED显示屏单元板中的应用

针对LED室内点阵显示屏单元板驱动电路采用通孔器件存在的一些问题，提出了采用SMD的解决方法，对两种封装形式的器件特点进行了比较，介绍了SMD在LED显示屏单元板中的具体应用；描述了SMD在LED显示屏领域中的发展趋势。     

硅一体化薄膜微电极器件及其应用

提出用发展中的硅微机械加工技术设计制作硅一体化薄膜微电极器件．这类微电化学器件具有微电极所特有的全部优点，而且由于结构上的一体化，便于器件整体的微型化和集成化．试用薄膜微电极器件电流法常温直接检测ＣＯ２气体，取得了满意的结果。设想通过器件三维构型设计的改进和完善，器件工作的长期稳定性可望进一步提高．     

Rheological and diffusion properties of a dextran-con A polymer in the presence of Insulin and Magnesium

Previous work carried out in our laboratories has focused on the formation and investigation of a dextran and concanavalin A (con A) based gel, which has the ability to alter its conformational structure in the presence and absence of free and terminal glucoses such that a gel–sol phase transition occurs. Here we report the diffusion and rheological investigations in to the effects of the addition of insulin and varyingconcentrations of magnesium chloride hexahydrate (Mg₂Cl₂6H₂O) at 20 and 37 °C. Rheological examination of glucose-sensitive (dextran-con A) gels were conducted using a cone and plate viscometer used in continual rotation and oscillatory modes. The results are interpreted in terms of the structure of the gel network and suggest rheological assessment provides an effective method of assessing the properties of gel systems. The subsequent testing of such formulations in in-vitro diffusion experiments revealed a reduction in the rate of diffusivity in the insulin marker, poly R-478 dye. The performance of this self-regulating drug delivery system has been examined and the addition of insulin and magnesium chloride may alter the way in which the gel operates as a drug delivery device and in the delivery of insulin. This may have implications for other ligands.     

The number of ideals in a quadratic field

LetK be a quadratic Geld, and letR(N) be the number of integer ideals inK with norm at most AT. Letx with conductork be the quadratic character associated withK. Then |R(N)−NL(1,x)|⩽Bk ^50/73 N ^23/73(logN)^461/146 forN ≥Ak, whereA andB are constants. ForN ≥Ak ^c,C sufficiently large, the factork ^50/73 may be replaced by (d(k))^4/73 k ^46/73. Dedicated to the memory of Professor K G Ramanathan