对氨基酚络合萃取机理的探讨

对氨基酚络合萃取机理的探讨;对氨基酚; 络合萃取; 萃取机理; 萃取反应热     

运动技能形成融合主体因素和主导因素的研究

通过对运动技能形成的主体因素和主导因素进行研究分析,揭示运动技能形成融合教师与学生“双边活动”共同努力的结果,为开发体育运动技能教学与学习的思路提供科学指导。     

过渡金属氢化物和聚集双键化合物反应的研究Ⅲ.用ESR方法考察二茂锆氢化物与RNCS的反应机理

本文用ESR方法考察了Cp₂ZrH) Cl与RNCSR=C₆H₅,c-C₆H₁₁,n-C₄H₉)的反应的过程,结果表明,在这类反应过程中,Zr-H键发生均裂,中心金属锆经过+4-→+3-→+4的价态变化,反应通过自由基机理进行.     

Random walk properties of lattices and correlation factors for diffusion via the vacancy mechanism in crystals

Random walk properties and correlation factors for diffusion via the vacancy mechanism are calculated and compared for various three-dimensional lattices. By applying the theory of random walks on an imperfect lattice, the correlation factor for impurity diffusion is calculated rigorously for the five jump frequency model in the fee lattice.Presented at the Symposium on Random Walks, Gaithersburg, MD, June 1982.     

小间隙高放大多丝室及其放电机制

对以强猝灭气体工作的小间隙多丝室及其放电机制进行了研究,实验表明,因为工作在饱和模式区,这种室同时具有很高的气体放大和相当快的时间特性.文中探讨了放电机制,雪崩中空间电荷效应以及电离光子的产生和作用是重要的因素,而其中后一因素又受到强猝灭气体的抑制.     

Phase formation and magnetic properties of Nd2Fe14B-type Nd16Co76B8−xCx alloys and their hydrides

An attempt is made to synthesize Nd₂Co₁₄C compound by mechanical alloying Nd₁₆Co₇₆B_8−xC_x (0x8) alloys and subsequent annealing. Phase formation and magnetic properties of Nd₂Fe₁₄B-type Nd₁₆Co₇₆B_8−xC_x alloys and their hydrides are investigated. The Nd₂Co₁₄(B,C) phase with Nd₂Fe₁₄B-type structure is formed for Nd₁₆Co₇₆B_8−xC_x (0x7) alloys, while NdCo₇C_δ phase with TbCu₇-type structure is observed in Nd₁₆Co₇₆C₈ alloy. The lattice parameter c of the Nd₂Co₁₄(B,C) phase decreases with increasing the carbon content. A limit volume of the unit cell to form the Nd₂Fe₁₄B-type structure is estimated to be 0.870 nm³. The spin-reorientation temperature T_SR increases with increasing the carbon content, due to an enhancement of magnetocrystalline anisotropy caused by carbon substitution for boron. After hydrogenation, the lattice expansion is observed for Nd₁₆Co₇₆B_8−xC_x (0x7) alloys. The spin-reorientation temperature of Nd₁₆Co₇₆B_8−xC_xH_y (0x7) is much lower than that of the host alloys. Some structural and magnetic properties of hypothetic Nd₂Co₁₄C and Nd₂Co₁₄CH_y compounds are estimated by extrapolation.     

线型聚能装药的理论研究

本文提出了一端起爆的线型聚能装药射流形成的不定常理论模型。根据这一模型,当金属罩在爆轰波作用下的运动速度为已知时,则不论此速度是否是时间或初始位置的函数,都能得到射流形成时的速度,质量和位置等参数。 按照本文模型,Defourneaux.M.的定常射流形成定常模型是一个简单的特例。我们利用本文的模型对等厚度装药的情况进行了计算,并与实验结果比较,两者符合良好。同时计算结果表明,考虑射流形成的不定常因素,可以较好地解释射流头部的质量堆积和射流内部的反向速度梯度等实验现象。本文的模型可以为线型聚能切割索的设计提供较为准确的理论指导。     

预裂爆破设计参数的理论分析

本文在分析不偶合装药爆破物理过程和动态冲击压力的基础上,研究了预裂孔的破坏型态;利用相应的破坏准则,推导了预裂孔临界和允许体积装药密度的理论计算式,并在总结已有的预裂成缝理论和实验成果的基础上,用裂断力学理论对成缝机理作了进一步探讨。考虑了岩体初始应力的影响,对裂缝扩展进行了定量描述,提出了预裂爆破炮孔间距的计算表达式。     

Analysis and modeling of resistive switching mechanisms oriented to resistive random-access memory

With the progress of the semiconductor industry,the resistive random-access memory(RAM) has drawn increasing attention.The discovery of the memristor has brought much attention to this study.Research has focused on the resistive switching characteristics of different materials and the analysis of resistive switching mechanisms.We discuss the resistive switching mechanisms of different materials in this paper and analyze the differences of those mechanisms from the view point of circuitry to establish their respective circuit models.Finally,simulations are presented.We give the prospect of using different materials in resistive RAM on account of their resistive switching mechanisms,which are applied to explain their resistive switchings.     

电子束蒸发在不同Ar气氛下外退火制备MgB2超导薄膜

制备高质量的MgB2薄膜是实现MgB2超导电子器件应用的前提和基础.我们用电子束蒸发B膜和Mg/B多层膜为前驱然后后退火的方法,分别在高温区(~900℃)和中温区(~750℃)成功获得了MgB2超导薄膜.改变退火的Ar气压条件,采用B膜前驱退火的样品Tc可达到38K以上,转变宽度0.3K.Mg/B多层膜的结果尽管Tc稍低(Tc~35K),但薄膜表面更加均匀,且避免了高温下Mg蒸汽污染的问题.对于两种前驱退火中观察到的完全不同的退火气压影响,我们认为是与其各自的超导成相过程相联系的,在此基础上我们对退火气压效应给出了自己的分析和解释,为今后进一步细致研究退火过程中的薄膜生长机制提供了参考.