Theoretical analysis of the acoustical characteristics of suspended micro-perforated panel absorbers

Sound absorption characteristics of suspended micro-perforated panel absorbers were investigated theoretically. The method of half thickness model of such panel absorber with quadripole analysis was used for predicting its acoustic performance. The analysis results show that the predictions agree well with the measurements of absorption in the reverberation chamber. The factors affecting the absorption characteristics for such absorbers were discussed, and some rules as design guidelines were given.     

Critical Point Theorems and Applications to Differential Equations

This paper contains a generalization of the well-known Palais-Smale and Cerami compactness conditions. The compactness condition introduced is used to prove some general existence theorems for critical points. Some applications are given to differential equations.     

NECESSARY CONDITIONS FOR OPTIMAL CONTROLS OF SEMILINEAR ELLIPTIC VARIATIONAL INEQUALITIES INVOLVING STATE CONSTRAINT

This paper deals with maximum principle for some optimal control problem governed by some elliptic variational inequalities. Some state constraints are discussed. The basic techniques used here are based on those in [1] and a new penalty functional defined in this paper.     

LB膜混合聚集体中极性基团相互作用对光学非线性的影响

通过紫外－可见吸收光谱、压力－面积等温线、二次谐波的测量，研究了不同活性分子混合聚集体的形成对ＬＢ膜光学性质的影响。分子极性基团间的相互作用，使激发态能量及平均偶极矩发生变化，导致ＬＢ膜的光学非线性明显地增强或减弱。     

A Fixed Point Theorem for Multi—valued Composite Increasing Operators

Ａ　Ｆｉｘｅｄ　Ｐｏｉｎｔ　Ｔｈｅｏｒｅｍ　ｆｏｒ　Ｍｕｌｔｉ－ｖａｌｕｅｄ　Ｃｏｍｐｏｓｉｔｅ　Ｉｎｃｒｅａｓｉｎｇ　ＯｐｅｒａｔｏｒｓＬｉＦｅｎｇｙｏｕ（李凤友）（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ，Ｔｉａｎｊｉｎ＇ＮｏｒｍａｌＵｎｉ...     

半序集下同调的研究概况及Quillen猜想的一个重要方面

１９７８年，Ｄ，Ｑｕｉｌｌｅｎ证明了：若群Ｇ有非平凡的正规ｐ－子群，则由ｐ－子群组成的半序集是可缩的。同时，他还猜想逆定理也成立。１９９３年，Ｍ．Ａｓｃｈｂａｃｈｅｒ和Ｓ．Ｄ．Ｓｍｉｔｈ证明了若群Ｇ不包含某种酉分支的话，则Ｑｕｉｌｌｅｎ猜想的确成立，在他们的证明中，Ｑｕｉｌｌｅｎ所证明的下述定理起着很重要的作用：由基本阿贝耳Ｐ－子群组成的半序集到所有Ｐ－子群组成的半序集的包含映射导出对应下同调的同构。以Ｂｕｃｈｓｂａｕｍ条件为重要的工具，本文将重新叙述此定理的证明。     

开关DC—DC变换器并联运行问题的研究

开关直流电源并联运行在许多场合应用。每一路电源输出阻抗的不一致性使每一路输出电流难以均衡，影响了系统的可靠性。本文提出了一种双回路ＤＣ—ＤＣ变换器的控制方案。由于采用电压环（外环）和电流环（内环）两环结构的双回路控制模式，变换器输出电流得到了有效控制，便于多个ＤＣ—ＤＣ变换器输出直接并联，从而实现了模块化，具有一定的实用性     

用导热性半固化片制造印制板

导热性半固化片对制造导热性电路板,近来变得通用了。实际上,印制电路板是用部分固化的(B-阶段)环氧树脂片或膜,即众所周知的半固化片加工的。半固化片在许多环氧,聚酰亚胺、氰酸脂和PTFE/玻璃纤维组成中是通用的,是为满足工业对高温稳定性、低介电常数和低热膨胀的要求而设计的。 然而,直到现在才能够提供导热的半固化片,同时对制造的PCB保持必要的电气绝缘。现在有效应用的导热的和电气绝缘的半固化片比标准FR-4半固化大10倍以上的导热率和1.5倍以上的介电强度。这些双重性质使之作为电路板组成部分之金属散热器的实际应用     

转移下半连续函数的极大极小原理及其应用

本文引入了转移下半连续的概念并在转移下半连续的条件下推了ＫｙＦａｎ极大极小原理。应用这一结果，证明了截口定理，不动点定理和函数不等式组解的存在性定理。