等离子体天线轴向密度数值模拟和辐射图计算     

赵国伟王之江  徐跃民梁志伟 徐杰 《中国科学院大学学报》2007,24(4):419-424

由于电子密度分布、激励功率、气压等因素的影响,等离子体天线参数（增益、方向图等）通常难以求解。本文利用时域差分建立电磁波沿等离子体天线激励和传播的模型,得到不同参数（如激励功率、碰撞频率、等离子体迟豫时间、每个电子对所需能量）对等离子体轴向电子密度分布的影响,解释了不同激励情况下电子密度的线性和非线性分布,并解决了信号沿等离子体天线传播的波矢分布、辐射方向图的求解问题。  相似文献   

等离子体及其应用          下载免费PDF全文

蒋莉  樊芷芸 《惠州学院学报》2000,(4)

本文简要介绍了等离子体的概况、应用及发展前景。  相似文献   

无氧和有氧运动对血浆脂蛋白的影响作用     

何仲涛 《四川体育科学》1997,(Z1)

对４８位健康妇女进行有氧和无氧运动，研究运动强度和运动时间对血浆脂蛋白的改善作用。研究发现：经过有氧和无氧运动，血浆ＨＤＬ和ＨＤＬ２的浓度，ＬＤＬ／ＨＤＬ、ＨＤＬ２／ＨＤＬ３、胆固醇／ＨＤＬ的比值都发生了明显改变。结论：运动强度和运动时间对血浆脂蛋白的改善起着重要作用，无氧运动不利于人体脂蛋白的改变，只有低强度、长时间的有氧运动能有效地改善脂蛋白水平，防止冠心病的发生  相似文献   

Separation of antihemophilic factor VII from human plasma by column chromatography     

V. M. Baikar  M. V. Kamath  C. Vishwanathan  A. M. Varadkar  S. E. Bharmal 《Indian journal of clinical biochemistry : IJCB》2003,18(1):80-86

TMAE-Fractogel 650 (M) (Trimethylaminoethyl) is an ion exchange medium can be used to capture factor VIII (F VIII) directly from plasma. Previous reports have focused on the use of DEAE-Fractogel 650 (M) (Dimethylaminoethyl) ion exchange medium to capture F VIII from cryoprecipitate and plasma. Our main objectives were (I) to standardise the purification of FVIII from human plasma by column chromatographic technique. (II) to study the recovery of FVIII activity in purified fraction at 18–20°C process condition. (III) to study the effect of virucidal step on recovery of FVIII activity and (IV) to study the effect of lyophilisation on FVIII activity. In this report, Citrate Phosphate Dextrose (CPD) plasma was batch stirred with dry DEAE-Sephadex A50, filtered, diluted, loaded on to a column packed with TMAE-Fractogel and chromatographed. Most of the unwanted proteins flowed through the gel unadsorbed. Bound F VIII was eluted by increasing the ionic strength of the buffer. This purification step gave an overall 80% recovery from the plasma with a specific activity of 0.97 IU FVIII/mg protein. The purified F VIII fraction was made virus safe by employing the virucidal technique developed by New York Blood Centre (NYBC). There was 48.43% loss of FVIII activity in Virus inactivation treatment and the loss of FVIII activity in lyophilisation was 8.45% which is acceptable. This method of purification gave a higher yield of FVIII than cryoprecipitation, and is a promising alternative method to cryoprecipitation of F VIII.  相似文献   

水平电偶极子在覆盖有等离子体的良导体上产生的电磁场的研究     

林国华  张业荣 《环球赛鸽科技》2015,(10)

本文研究了水平电偶极子在覆盖有等离子体的良导体上产生的电磁场。总电磁场包括了直射波,理想反射波,侧面波和缺陷表面波。因为等离子体的折射系数是随频率变化的复杂函数,所以用于计算缺陷表面波的极点函数的解也是频率的函数。研究了频率对极点方程及其解的影响,并分别计算了直射波,理想反射波和侧面波之和、总场强、以及缺陷表面波的值。由于金属表面的介电常数可以在很宽的频率范围内表示为等离子体,所以本文的研究成果可以用于集成微带线电路或者微带天线等。  相似文献