Global exponential stability analysis for cellular neural networks with variable coefficients and delays

Some sufficient conditions for the global exponential stability of cellular neural networks with variable coefficients and time-varying delays are obtained by a method based on a delayed differential inequality. The method, which does not make use of Lyapunov functionals, is simple and effective for the stability analysis of cellular neural networks with variable coefficients and time-varying delays. Some previous results in the literature are shown to be special cases of our results.      

濮城油田沙一、二段原始含油饱和度计算方法探讨

为准确计算濮城油田沙一、二段原始含油饱和度，从水基泥浆取心井法、电阻率法、阿尔奇公式法、物性公式法、粒度中值经验公式法、驱动压力法、毛管压力法等7个方面进行研究，并探讨各方法之间的异同点，进而进取较合理的油藏含油饱和度值。     

A switching power amplifier with feedback for improving total harmonic distortion

A high efficiency and low distortion and switching power amplifier is proposed. We use feedback to reduce the total harmonic distortion (THD) and the DC output bias current. The experimental results show that the proposed circuit has 0.24% total harmonic distortion and 91% power efficiency while the DC output bias current is 12 μA at 1.5 V supply voltage.     

A prospective study of the accuracy of clinical examination evaluated by arthroscopy of the knee

Endotoxin activates white blood cells and complement and produces a spectrum of clinical syndromes ranging from fever to septic shock. Although production of endogenous endotoxemia during cardiopulmonary bypass (CPB) has recently been reported, the role of hypothermia on endotoxemia is not clear. In this study, we evaluated the effects of moderate (24-28 degrees C) and mild (32-34 degrees C) hypothermia on blood endotoxin levels. The study population consisted of 20 patients who underwent coronary artery bypass grafting (CABG) with CPB. Moderate systemic hypothermia was applied during aortic cross-clamping in ten patients (group 1) and mild hypothermia in the remaining ten patients (group 2). The mean rectal temperatures were 26.8 +/- 1.2 degrees C in group 1 and 33.8 +/- 0.8 degrees C in group 2. The blood samples for endotoxin level measurements were obtained before CPB, during aortic cross-clamping, immediately after the release of the cross-clamp, 20 minutes after the release of the cross-clamp, after CPB, and 2 hours postoperatively. There were no endotoxins in any of the samples before CPB, but it was detected after CPB in both groups. The endotoxin levels were significantly higher in group 1 than in group 2. The present study suggests that when hypothermia is the technique of choice, the deleterious effects of endotoxemia on patients with comorbidity must be considered.