PT整环的研究

引入了PT整环的概念,通过例子说明PTW整环不是PT整环,刻画了PT整环的局部化性质;然后讨论了其拉回图;最后对PT整环的几类扩环的性质进行了描述.     

Potential transformation methods for large-scale constrained global optimization

Several techniques for global optimization treat the objective functionf as a force-field potential. In the simplest case, trajectories of the differential equationmx=–f sample regions of low potential while retaining the energy to surmount passes which might block the way to regions of even lower local minima. Apotential transformation is an increasing functionV:. It determines a new potentialg=V(f), with the same minimizers asf and new trajectories satisfying . We discuss a class of potential transformations that greatly increase the attractiveness of low local minima.These methods can be applied to constrained problems through the use of Lagrange multipliers. We discuss several methods for efficiently computing approximate Lagrange multipliers, making this approach practical.     

基于触摸屏和PLC的多路温度监控系统

提出一种具有设备故障自动提示功能的多路温度监控系统．采用三线式PT100温度传感器、DVP-SS系列可编程控制器和2个温度模块DVP-04PT实现8路温度信号的采集与控制;采用触摸屏实现参数的显示、设定、系统故障提示等功能;给出了一种按位显示温度模块错误状态的故障提示方法．实践表明,该系统运行可靠,维护方便,节省调试和维修时间,可广泛应用于32路以下的温度控制．     

Calculation of Three-dimensional Electrostatic Field in Potential Transformers

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Compositional variation in 0.65 PbMg2/3Nb1/3O3 ‐0.35 PbTiO3 single crystals grown by high temperature solution growth technique

Single crystals of lead magnesium niobate titanate, 0.65 PbMg_2/3Nb_1/3O₃ (PMN) ‐0.35PbTiO₃ (PT) were grown using flux method near morphotropic phase boundary (MPB) composition. The crystals grown at the centre of the platinum crucible were found to PT deficient compared to those grown near the walls of the crucibles. A variation of ∼3.8 mol% in PT concentration was found in the crystals grown at the wall and at the centre of the crucible. The difference in the chemical composition of crystals grown at the centre and the near the wall of the crucible was observed by X‐ray diffraction, EDXRF, dielectric and thermal measurements. The presence of PT rich and deficient crystals is explained in terms of the segregation coefficient of PT in PMN. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

ee0A GeV S+Au反应中光子产生的低横动量增强

用建立在LUND弦模型特别是PYTHIA事件产生器基础上的描写极端相对论性核一核碰撞的强子和弦级联模型—JPCIAE研究了入射能量为200A GeV的S+ Au中心碰撞中光子产生.模型同时考虑了部分子QCD散射过程、强子末态相互作用以及强子衰变等光子产生反应道并作了协调处理.JPCIAE模型计算结果很好再现了WA93实验数据所呈现的低横动量增强效应.     

Pb(Mg1/3Nb2/3)O3-0.33PbTiO3晶体三方相的压电性能研究

以坐标系二次旋转为理论基础研究了PMN-0.33PT晶体三方相的常用压电模量d15、d24、d31、d33、d36和机电耦合系数k15、k24、k31、k33、k36在三维空间的变化规律.通过MATLAB编程求得以上各系数关于坐标系旋转角度的函数表达式,绘制出了它们的三维空间分布图,并一一求得这些系数的最大值,以及与最大值相对应的旋转角.发现除d33和k33外,d31、d36、k31和k36也在空间变化显著.d31和k31旋转后的最大值比原坐标系下的数值分别扩大了15倍和6倍,对应的旋转角分别为(-4.5°/90°)、(22.5°/270°).d36 和k36在原坐标系下不存在,经旋转后的最大值可分别达到1340 pC/N 和0.73.该研究结果对PMN-0.33PT晶体在压电传感器、换能器中的应用具有重要的理论价值.     

一类商环的Grothendieck群

本文研究了商环Ｒ／Ｉ的Ｋ_０群，证明了：设Ｒ／Ｉ∈ＰＴ，Ｉ?Ｊ（Ｒ），则Ｋ_０Ｒ≈Ｋ_０（Ｒ／Ｉ）当且仅当幂等元关于Ｉ可提升．并进而给出了Ｅｘｃｈａｎｇｅ环的一个特征．     

PT燃油泵实验台的数字化研究

介绍了用微机与金属管浮子传感器和单片机组成测定装置,代替用玻璃浮子量油的传统PT燃油泵试验台,解决了目前PT燃油泵试验台现存的量油系统误差大的问题,从而使我国在试验柴油机PT泵总成方面有新的提高。     

PT6311在DVD前面板控制电路中的应用

介绍了PT6311的性能特点、控制命令、编程指令的实现方式以及它在DVD刻录机前面板电路中的实际应用。