强我中华——健元文化探秘

人们都知道，无论企业还是人体就怕伤元气，到底什么是元气，大家却似懂非懂，但至少知道它太重要了谁也伤不起。     

智者养元 善者结缘——健元文化探秘第二辑

沉寂千年的健元文化 天地之大德,所以生生者也。元字从二从人,仁字从人从二,在天为元,在人为仁,在人身则为体之长。——《精蕴》 何为元气？ 中国古代朴素的“元气论”认为“元气”是构成宇宙万物的最本质、最原始的要素,其源头可认为是老子的“道”。按照元气论,万物的产生、灭亡和发展变化都是元气循“道”（即自然规律）而运动的结果,气为万物之精微,完全连续而无处不在。     

直流电机模型参数的直接辨识

直流电机的数学模型计算是直流调速系统设计的重要环节,传统方法求解得的直流电机模型参数误差大,且不能获得在线参数辨识。为了求出精确的直流电机模型参数,该文给出了求解直流电机数学模型的直接辩识算法,并以一个电机的实验为例,分别用传统方法和直接辨识算法求出了这个电机的模型参数,和阶跃响应曲线。通过对这两种方法所求得的结果进行仿真比较,证明直接辨识算法可行,模型的精确性有明显改善。     

频率合成技术在DC/AC逆变电源中的应用

介绍了频率合成技术应用在分段同步调制三相变频电源中的必要性和使用方法。最后给出了一个设计例子。将频率合成技术引入到DC／AC变换器中,为SPWM控制电路提供了一个新的思路。     

回热式布雷顿-两平行逆布雷顿联合循环第一定律分析与优化

提出了回热式布雷顿-两平行逆布雷顿联合循环模型。对该模型进行了第一定律性能分析与优化,得出了该循环最优效率和最优比功的表达式,分析了回热度及其他参数对联合循环最优热效率和最优比功的影响。分析表明,增加回热器后能提高联合循环的热效率,但此时联合循环的输出比功较小。     

焦炉煤气驱动回热式燃气轮机装置热力学分析

建立利用富余焦炉煤气驱动的回热式燃气轮机装置模型,应用经典热力学和燃气轮机循环理论,对该装置热效率和输出功进行分析。通过数值计算,分析了煤气放散率、煤气富余率和回热器有效度等参数对装置性能的影响。结果表明:降低煤气放散率和提高煤气富余率时,装置的输出功都能得到提高;增加回热器后,装置热效率和输出功都得到了提高,焦炉煤气得到了有效的利用;分别存在1个最佳的压气机压比使装置热效率和功率达到最大值,即可通过合理选取压气机压比,使装置性能最优。     

大采高条件下走向长壁矿压规律研究

 以新疆焦煤集团艾维尔沟矿区5#煤层走向长壁大采高开采为工程背景,针对其硬顶、软底、软煤的赋存特点,采用实验室相似材料模拟的研究方法,实现了从开切眼到停采中走向方向上的全过程相似实验模拟。通过对实验数据的整理和分析,在大采高的开采条件下,工作面支架受载情况在数值的大小上呈现“一大一小”, 在数值的变化上呈现“稳定—基本稳定—变化剧烈”的规律,并在一定程度上反映出工作面矿压显现的剧烈程度;煤壁前方的应力峰值随着工作面的推进而向前移动,其呈现先增大后减小,再增大的趋势,其峰值的应力集中系数较大,而起伏变化较小;上覆岩层的位移存在先小后大的变化规律,在实验过程中,存在“切顶”现象,具有明显的”三带”分布特征。     

Generation of reactive species in atmospheric pressure dielectric barrier discharge with liquid water

Atmospheric pressure helium/water dielectric barrier discharge(DBD) plasma is used to investigate the generation of reactive species in a gas–liquid interface and in a liquid. The emission intensity of the reactive species is measured by optical emission spectroscopy(OES)with different discharge powers at the gas–liquid interface. Spectrophotometry is used to analyze the reactive species induced by the plasma in the liquid. The concentration of OH radicals reaches 2.2 μm after 3 min of discharge treatment. In addition, the concentration of primary longlived reactive species such as H_2O_2, NO_3~- and O_3 are measured based on plasma treatment time.After 5 min of discharge treatment, the concentration of H_2O_2, NO_3~-, and O_3 increased from 0 mg?·?L~(-1) to 96 mg?·?L~(-1), 19.5 mg?·?L~(-1), and 3.5 mg?·?L~(-1), respectively. The water treated by plasma still contained a considerable concentration of reactive species after 6 h of storage. The results will contribute to optimizing the DBD plasma system for biological decontamination.     

无电压传感器双回路DC/DC变换器设计与仿真

为了提高电源的抗扰动性,降低取样电路的复杂程度,依据降维观测器理论,提出一种无输出电压传感器的双回路DC/DC变换器的设计方法,并进行仿真,证实无电压传感器双环控制DC/DC电源设计的合理性。     

Two-dimensional self-consistent numerical simulation of the whole discharge region in an atmospheric argon arc

A 2D self-consistent numerical model of the whole argon-arc discharge region that includes electrodes is developed in this work to facilitate analysis of the physical processes occurring in atmospheric arc plasma. The 2D arc column model contains the ionization and thermal non-equilibrium, which is coupled with a 1D electrode sheath model. The influence of plasma-species diffusion near the electrode region is investigated based on Maxwell–Stefan equations and the generalized Ohm's law. The numerical results of argon free-burning arcs at atmospheric pressure are then investigated. The simulation shows that the plasma is obviously in the state of thermal and ionization equilibrium in the arc core region, while it deviates from thermal and ionization equilibrium in the arc fringe region. The actual electron density decreases rapidly in the near-anode and near-cathode regions due to non-equilibrium ionization, resulting in a large electron number gradient in these regions. The results indicate that electron diffusion has an important role in the near-cathode and near-anode regions. When the anode arc root gradually contracts, it is easy to obtain a positive voltage drop of the anode sheath (I = 50 A), while it remains difficult to acquire a positive anode sheath voltage drop (I = 150 A). The current–voltage characteristics predicted by our model are found to be identical to the experimental values.