沉积物-水界面通量测定中热脉冲信号分析(英文)

分析了热脉冲传感器脉冲信号与沉积物-水界面通量之间的传热问题,并通过优化程序,提出了用热脉冲测定计算界面通量J的新方法.此分析方法只需3个实验参数,即x0,λ和(pc)l就可利用热脉冲测定数据计算出沉积物-水界面通量J.数据分析结果表明:热脉冲顶点温度到达时间与水流速度呈曲线关系;沉积物-水界面通量和热源上下游温升比值的自然对数之间存在一种简单的线性关系.这种简单的线性关系,有利于热脉冲型传感器在土壤-水界面通量测定中的广泛应用.     

GaAs光导开关瞬态特性实验研究

介绍了光导开关的加工过程与测试设计，报告了光导开关分别在jns与ps激励脉冲光源激发下，处于线性工作模式时的实验结果。根据实验结果，文章对光导开关的瞬态特性作了简单分析。     

中国股票市场科技股价格波动的统计分析

科技股的价格波动是金融理论界和实务界的关注热点之一。文章将协整模型与ARCH模型和GARCH模型相结合，探讨了科技股板块的价格波动特征；进而采用脉冲响应函数和方差分解法研究了科技股指数波动和市场指数波动的相互冲击效应和相互影响程度。     

微型企业信贷融资问题与对策

微型企业为我国经济发展作出了突出贡献,但融资难却成为制约微型企业发展的最大障碍.本文总结了我国微型企业信贷融资概况以及存在的问题,在此基础上,分别从政府与监管部门、银行和微型企业自身角度提出了解决我国微型企业融资问题的主要途径,最后对"微贷款"这一信贷模式进行分析,得出"微贷款"是解决微型企业信贷融资困境的有效实践.     

Impact of Vascular Function on Maximum Power Output in Elite Handball Athletes

ABSTRACT

Purpose: To evaluate vascular function and its relationship to cardiorespiratory fitness in professional handball athletes. Method: We examined 30 male professional handball athletes (age 27 ± 4 y) and 10 male sedentary controls (age 26 ± 5 y) at rest. The workup included exercise testing via ergometry. To assess vascular function, a validated electronic model of the arterial tree (vasc assist 2®) was used. It replicates noninvasively acquired pulse pressure waves by modulating the relevant functional parameters of compliance, resistance, inertia, pressure, and flow. The maximum oxygen uptake (VO2max) was estimated using the validated heart rate ratio method. Results: Athletes had a significantly lower systolic and diastolic central blood pressure (cBP) compared to controls (102 ± 9/60 ± 9 vs. 110 ± 8/74 ± 9 mmHg, p < .01), whereas aortic pulse wave velocity (PWV) (6.2 ± 0.8 vs. 6.3 ± 0.5 m/s, p = .45) and augmentation index at a heart rate of 75 (Aix@75) (?4 ± 12 vs. ?13 ± 16%, p = .06) were not different. Resistance index (R) (15.9 ± 4.4 vs. 10.6 ± 0.6, p = .001) and maximum power output (MPO) (3.55 ± 0.54 vs. 2.46 ± 0.55 Watt/kg, p < .001) were significantly higher in athletes compared to controls. We found no relevant correlation between MPO, resting heart rate, PWV, Aix@75, and cBP. A higher VO2max (p = .02) and a lower R (p < .01) were significant predictors of a higher MPO in athletes. Conclusion: R had an independent and strong correlation to MPO in athletes, which might help to disentangle the contribution of aerobic capacity and arterial function to physical power.     

初始脉冲下系统动力学延迟环节的响应表达式

给出了初始脉冲下系统动力学延迟环节的响应表达式,纠正了文[1,2]中的错误.     

废气污染物排放计算方法在火力发电行业普查中的应用

在污染源普查中通过具体实例分析了废气污染物排放计算方法的有效性、实用性和准确性。     

KC－2型油份监测仪及其微机系统

本文主要介绍ＫＣ－２型油份监测仪的测量原理及其微处理机系统。该仪器采用了机械簧片哨式超声乳化，红外光透、散射、光纤传导及单片微处理机技术。因此，其性能指标得到了提高，并实现了对水中含油浓度的全自动连续在线监测，而又不造成二次污染。     

Velocity field control of robot manipulators by using only position measurements

In the velocity field control approach the robot motions are specified through a vectorial function that assigns the desired velocity to each point of the configuration space. In other words, a velocity field defines the robot desired velocity in the operational space as a function of its current position. In this paper is introduced a new algorithm to solve the velocity field control formulation in the robot operational space. The proposed approach assumes only joint position measurements and is based on a hierarchical structure that results of using the kinematic control concept and a joint velocity controller. To estimate the joint velocity, nonlinear filtering of the joint position is used.     

基于LabVIEW的虚拟核脉冲幅度甄别器设计

基于LabVIEW设计一个虚拟核脉冲幅度甄别器,对虚拟信号发生器产生的模拟核信号进行甄别分析.结果表明,在实验教学中,用基于软件体系结构的VI系统代替基于硬件体系结构的传统仪器,不仅节省仪器购买、维护等费用,还可增强实验教学效果.