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21.
 将爆磁压缩等效为电流源的方法,对爆磁压缩发生器通过脉冲变压器对脉冲形成线充电进行了理论分析,得出爆磁压缩发生器在负载上产生电流波形(简称负载电流)为直线情况和任意电流波形情况下充电电流和充电电压的表达式。分析表明变压器耦合互感与负载电流随时间变化增长率是脉冲形成线充电的两个重要参数,脉冲形成线第一个充电电压峰值与变压器的耦合互感和负载电流波形斜率成正比,负载电流波形斜率的变化可以改变充电电压峰值的时间,斜率不断增加可以延长第一个充电电压峰值时间,从而可能增加充电电压的幅值,提高爆磁压缩发生器能量的利用效率。  相似文献   
22.
喷气Z箍缩内爆等离子体的雪铲模型   总被引:1,自引:0,他引:1       下载免费PDF全文
 在喷气Z pinch内爆等离子体研究中,雪铲模型是一种常用的、比较简单的物理模型。根据实验中提供的电流波形,负载线质量和初始半径,可以通过雪铲模型来估算内爆到心的时刻。根据一维运动方程和不同构形下的解析解以及部分实验结果相结合,讨论了雪铲模型的适用范围。数值计算的内爆时间和实验(Gamble II, Double EAGLE, BLACKJACK 5)测量值符合得较好。结果表明,雪铲模型在喷气Z pinch实验的负载优化设计研究中是很有参考价值的方法。  相似文献   
23.
There is considerable interest in protein adsorption onto microspheres because of its importance in a wide range of biomedical applications, such as artificial tissues and organs, drug delivery systems, biosensors, solid-phase immunoassays, immunomagnetic cell separation and immobilized enzymes or catalyst. It has been well known that the interaction between proteins and microspheres plays important roles in this process. Major interaction involved in the adsorption can be classified as electrostatic, hydrophobic and hydrogen-bonding. Indeed, adsorption of proteins onto microspheres is a complex process and often can involve many dynamic steps, from the initial attachment of the protein on the surface of microspheres to the equilibrium. Also the conformation of proteins probably occurs to a certain degree of deformation or structural change due to the large area of contact. Recently, much interest has been shown in sulfonated microspheres, since sulfonate-group itself is one of components in bio-bodies, as well as is sensitive to the change of pH or ionic strength. Indeed, so far, scanty investigations have been performed in the full range. Also few researches have involved the data on adsorption rate and the maximum amount of protein adsorbed, or the reversibility of the process and conformational change of protein adsorbed as well.In present study, BSA (bovine serum albumin) was chosen as the model protein and sulfonated PMMA [poly(methyl methacrylate)] microspheres as the matrix to investigate the adsorption process.The purpose is to show some information especially the intrinsic information involved by the adsorption process Adsorption of BSA onto sulfonated microspheres (MS) has been investigated as a function of time, protein concentration and pH. The adsorption appears to be a reversible process and the presence of sulfonate groups can play important roles in the adsorption process, so as to increase the amount of protein adsorbed and influences the interaction of BSA molecules. Fig. 1 also shows that the reciprocation between unadsorbed and adsorbed BSA or rearrangement of adsorbed BSA molecules does not produce visible change in the properties of the adsorbed protein. Close to the isoelectric point of BSA (pI 4.7), the amount of protein adsorbed exhibits a maximum. A higher or lower pH results in the significant decrease of the adsorption amount. This is related to the dependence of BSA conformations at different pH conditions.  相似文献   
24.
The immobilization of proteins, especially receptor proteins commonly used in high through-put screening of drugs (HTS), have received great attention in recent years. There are many successful isothermal models for describing the adsorption of protein onto solid surface, such as Langmuir model, Bi-Langmuir model, Fowler model, Freundlich model, Freundlich-Langmuir model and Tekmin model etc. In all these models, Langmuir model was the most favorable one model accepted by many researchers, but the experimental results showed that it was not entirely fit to all adsorption behaviors. So new models were required for describing protein adsorption onto microspheres in different conditions.In our research, a novel isothermal model, including Langmuir and other adsorbing behaviors was presented basing on the holding degree of surface active sites and the interaction styles of protein immobilization. In Langmuir model, the adsorbing amount of protein was described as [PS] =Km[P]/1 + K[P], where [PS] was the concentration of adsorbed protein, [P] was the concentration of freeprotein at equilibrium state, and Km and K was constant. According to the interactions of protein and ligands, there were three patterns in the interactions of protein and ligands. On the similar assumption that the interaction of protein and microspheres were three styles, and based on the definition of the holding degree of surface active sites (Y), three adsorption behaviors could be described as Y K[ P ]φ/ K[P]φ+1 or ln K + φ ln[P] =ln(Y/1-Y) in which [P] was the concentration of free protein at equilibrium state, and φ and K was constant. Different scale of φ presented different adsorption behaviors, especially when φ was 1, the adsorption behavior was Langmuir adsorbing model. Figure I indicated the different adsorbing results in different adsorption behaviors (φ>1, φ<1,and φ=1).  相似文献   
25.
The crystal structures of two potential tumor imaging agents and therapeutic agents -copper(Ⅱ) complexes with salicylidene-tyrosinato Schiff base and nitrogen-donor chelating Lewis base, [Cu(sal-tyr)(bipy)] 1 and [Cu(sal-tyr)(phen)]2CH3OH 2 are presented. Our work is helpful to get deep understanding of novel 64Cu tumor imaging agents and therapeutic agents.  相似文献   
26.
对磁弹耦合在决定纳米晶软磁合金宏观磁性中的作用进行了探讨,高场磁化规律以及正电子湮没测量表明:对Fe73.5Cu1Nb3Si13.5B9合金,准位错偶极子造成的应力场对畴壁的钉扎效应是造成纳米晶软磁合金矫顽力的重要原因;结构缺陷造成的应力场与磁致伸缩的耦合作用对纳米晶软磁性能有重要的影响.在结构各向异性和磁弹耦合能共同作用下可解释纳米晶合金表现出最佳软磁性能.  相似文献   
27.
Cobalt antidot arrays with different thicknesses are fabricated by rf magnetron sputtering onto porous alumina substrates. Scanning electron microscopy and grazing incidence x-ray diffraction are employed to characterize the morphology and crystal structure of the antidot array, respectively. The temperature dependence of magnetic properties shows that in the temperature range 5K--300K, coercivity and squareness increase firstly, reach their maximum values, then decrease. The anomalous temperature dependences of coercivity and squareness are discussed by considering the pinning effect of the antidot and the magnetocrystalline anisotropy.  相似文献   
28.
主要介绍了丝绸之路上多元文化的典型代表——艾德莱斯绸.文章重点介绍了艾德莱斯绸的历史和传说,扎经染色工艺,各类艾德莱斯绸的特点及典型的艾德莱斯绸图案.  相似文献   
29.
本文给出了Banach空间广义分解定理的一个初等证明,并利用它来证明两个对称不等式.这是首次在Banach空间获得这样的不等式.  相似文献   
30.
The complete and incomplete aggregation-annihilation processes are investigated with the method of generating function, and the scale exponents are obtained exactly. We find that the scale exponents of incomplete aggregation-annihilation process are different from the previous exponents obtained by different methods. The time dependence of the total number of clusters and the total mass of clusters are analytically obtained.  相似文献   
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