基于CIS的轻柴油蒸馏流量检测系统的误差分析及减小误差的措施

对新设计的基于CIS的轻柴油蒸馏流量检测系统,分析了可能产生检测误差的主要原因,采取了减小误差的措施,取得了令人满意的效果。     

相位差模糊控制在线控制算法中的应用设计

在两级递阶控制模型基础上,针对不同的控制参数,完成相应的模糊控制器设计。详细介绍了相位差模糊控制器的原理和设计过程,并将交通信息参数的变化量加入到了模糊控制器的输入中,增加了模糊控制器的准确性和全面性。通过对实际干线的实例仿真证明本设计方法可以有效地减少车辆的平均延误时间。     

基于水平集算法的扩展有限元方法研究

扩展有限元是一种以单位分解思想为基础,在常规有限元位移中加入跳跃函数和渐近位移场函数,以处理不连续问题的数值方法。将水平集算法应用到裂纹界面的描述及加强单元类型的判别,并与扩展有限元相结合,用于分析材料断裂问题。相比传统有限元,有限元网格与裂纹面位置相互独立,不需满足裂纹为单元边、裂尖为单元节点和在裂纹附近进行高密度的...     

基于DSP的基本原则和补救方法

介绍了以非数学的方法描述了数字信号数字处理的基本原理和现实意义,同时介绍了数字信号处理最常见的步骤,详细分析了各部分依据和由此产生的问题,并指出必须采用的补救手段。     

氧化锌压敏电阻老化过程中非线性系数变化的研究

根据氧化锌压敏电阻(MOV)的非线性特征,结合双肖特基(Schottky)势垒理论和氧化锌陶瓷在小电流区的导电机制,提出了氧化锌压敏电阻老化劣化过程中必然伴随着非线性系数α的变化的结论.针对一种型号的MOV,通过大量实验数据分析得出:在不同老化劣化实验条件下,MOV的非线性系数α均随劣化程度的增加而呈下降趋势;在标称电...     

Changes in muscle morphology, electromyographic activity, and force production characteristics during progressive strength training in young and older men

Effects of a 10-week progressive strength training program composed of a mixture of exercises for increasing muscle mass, maximal peak force, and explosive strength (rapid force production) were examined in 8 young (YM) (29+/-5 yrs) and 10 old (OM) (61+/-4 yrs) men. Electromyographic activity, maximal bilateral isometric peak force, and maximal rate of force development (RFD) of the knee extensors, muscle cross-sectional area (CSA) of the quadriceps femoris (QF), muscle fiber proportion, and fiber areas of types I, IIa, IIb, and IIab of the vastus lateralis were evaluated. Maximal and explosive strength values remained unaltered in both groups during a 3-week control period with no training preceding the strength training. After the 10-week training period, maximal isometric peak force increased from 1311+/-123 N by 15.6% (p <.05) in YM and from 976+/-168 N by 16.5% (p <.01) in OM. The pretraining RFD values of 4049+/-791 N*s(-1) in YM and 2526+/-1197 N*s(-1) in OM remained unaltered. Both groups showed significant increases (p < .05) in the averaged maximum IEMGs of the vastus muscles. The CSA of the QF increased from 90.3+/-7.9 cm2 in YM by 12.2% (p <.05) and from 74.7+/-7.8 cm2 in OM by 8.5% (p <.001). No changes occurred in the muscle fiber distribution of type I during the training, whereas the proportion of subtype IIab increased from 2% to 6% (p < .05) in YM and that of type IIb decreased in both YM from 25% to 16% (p < .01) and in OM from 15% to 6% (p < .05). The mean fiber area of type I increased after the 10-week training in YM (p < .001) and OM (p < .05) as well as that of type IIa in both YM (p < .01) and OM (p < .01). The individual percentage values for type I fibers were inversely correlated with the individual changes recorded during the training in the muscle CSA of the QF (r=-.56, p < .05). The present results suggest that both neural adaptations and the capacity of the skeletal muscle to undergo training-induced hypertrophy even in older people explain the gains observed in maximal force in older men, while rapid force production capacity recorded during the isometric knee extension action remained unaltered during the present mixed strength training program.     

Identification of a novel endogenous memory facilitating cyclic dipeptide cyclo-prolylglycine in rat brain

Using high-performance liquid chromatography, gas-chromatography and chromato-mass spectrometry methods a novel endogenous cyclic dipeptide cyclo-prolylglycine was identified in rat brain. Its content according to gas chromatography is 2.8 +/- 0.3 nmol/g wet brain. Synthetic cyclo-prolylglycine has demonstrated antiamnesic activity in the passive avoidance test in rats at a dose of 0.1 mg/kg i.p. Cyclic dipeptide cyclo-prolylglycine seems to be a memory facilitating substance and its presence in rat brain suggests the existence of a new mechanism of memory regulation.     

FMEA技术在CDMA直放站中的应用

结合CDMA直放站系统，对FMFA技术的应用进行了较详细的介绍，分析了CDMA直放站潜在的故障模式，并给出了设计建议。     

Acute hormone responses to heavy resistance lower and upper extremity exercise in young versus old men

In the final stage of amyotrophic lateral sclerosis (ALS) the majority of patients develop chronic respiratory failure due to respiratory muscle weakness. The interaction between the patient with ALS and the physician should be characterized by continuous communication, especially with respect to the prospect of ventilatory failure and for support. The patient and his family must be informed thoroughly about the natural history and the prognosis of ALS, depending on the individual disease process. Already in the early stage of the disease coping strategies should be discussed so that imminent respiratory emergencies can be handled. If ALS patients are not informed about the acute respiratory insufficiency they run the risk of having to be intubated and mechanically ventilated over a long term. If dyspnea and hypersecretion dominate the final stage of ALS, the therapeutic strategy consists of the administration of morphine, insufflation of oxygen and bronchoscopic suction. Mechanical ventilation should only be initiated in the exceptional case. However, if dyspnea occurs in the early stage of the disease, when there is no bulbar paralysis and peripheral muscle function is intact, then noninvasive mechanical ventilation via mask may improve the quality of life substantially. Nevertheless, invasive mechanical ventilation via a tracheostomy should be avoided.