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1.
发射光谱法测定二氧化锆中钙,镁,铝,铁,钛,铪,硅   总被引:2,自引:0,他引:2  
本文介绍了用碳酸钡作缓冲剂测定二氧化锆中Mg,Fe,Al,Ca,Ti,Hf,Si杂质元素的发射光谱方法。该方法直接压样于普通电极中,简便,快速。取得了满意的结果。  相似文献   

2.
本文研究了贵金属标准溶液除氯离子的有关问题,解决了高纯硝酸银中贵金属等杂质元素的样配制,以硝酸银直接压样于普通电极中直流电弧激发,可测定99.0-99.99%的高纯银,该方法简便、快速、准确。  相似文献   

3.
ICP-AES同时测定铝合金中Fe,Si,Cu,Mg,Mn,Ni,Zn,Ti,Cr,Sr等杂质元素   总被引:13,自引:0,他引:13  
本文通过基体干扰和操作条件的试验研究,分别用基体匹配法和干扰系数法校正基体干扰和待测元素间的干扰,建立了以氢氧化钠溶样,ICP-AES同时测定铝合金中铁、锰、铜、锌、镁、钛、硅、镍、铬、锶等杂质元素的方法。方法快速、简便、可靠,回收率93%-102%,适用于进出口铝合金的快速检验。  相似文献   

4.
本文建立了一种简便快速、准确测定进口硫酸铜中铁、铅、锌、镍的火焰原子吸收方法(FAAS)。利用测定主成份的废液直接测定四种杂质,不需另外制备样品,简化了操作步骤,省时省力,节约试剂,且灵敏度好,准确性高,有一定的推广和应用价值。  相似文献   

5.
在聚变堆条件下,等离子体中杂质将严重影响燃料的浓度,并产生大量的功率损失而倍受关注。普遍用于托卡马克等离子体杂质输运研究的方法是瞬态扰动法,主要以主动注入杂质源来研究杂质的扩散和对流过程。短脉冲型的杂质注入一般可采用快过程的压电阀和激光吹气两种方式,而激光吹气方法是一种不容置疑的最好的杂质输运研究方法,因为杂质的注入时间和注入量都可以得到很好的控制,几乎能研究任何状态的等离子体杂质输运过程并对等离子体参数的扰动最小。杂质输运信息可通过探测杂质离子的辐射来得到,这些辐射主要包括由光谱仪测量的线辐射信号和由软X射线成像技术得到的软X射线辐射信号,通过这些测量可带出杂质分布的空间和时间演化的信息,再利用数值模拟计算编码,重建实验数据,从而得到杂质输运的扩散系数D、对流速度V和约束时间等。  相似文献   

6.
HT-6M托卡马克装置杂质输运   总被引:1,自引:0,他引:1       下载免费PDF全文
徐伟  万宝年  谢纪康 《物理学报》2003,52(8):1970-1978
利用多道可见光谱探测系统和近紫外转镜系统测量了HT-6M托卡马克等离子体中杂质的时空分布.建立完备的杂质输运程序,数值模拟碳、氧杂质在欧姆放电时的输运行为,得出了杂质的扩散和对流系数、不同电离态杂质离子密度、辐射功率密度和有效电荷数的空间分布. 分析低混杂波电流驱动(LHCD)期间杂质行为,结果表明等离子体粒子约束、杂质约束和能 量约束提高,辐射功率和有效电荷数减小. 关键词: 托卡马克 杂质输运 扩散系数 对流系数  相似文献   

7.
潘必才;  夏上达 《物理学报》1995,44(5):745-754
采用DV-Xα方法对多孔硅形成过程中位于表层的B和P杂质原子的作用进行研究,结果表明位于顶层硅原子层中的B和P杂质原子均可削弱其邻近的Si-Si键强度,因而可能导致出现腐蚀的突破点,再通过分析杂质对表面区势场的改变,可以认为位于顶层硅原子层中的B杂质原子产生腐蚀的突破点的可能性更大。 关键词:  相似文献   

8.
薄膜体内缺陷对损伤概率的影响   总被引:2,自引:0,他引:2       下载免费PDF全文
由实验中得到的激光损伤概率与表面杂质密度的关系出发,结合XRD测试和激光损伤测试的结果,得到体缺陷或杂质破坏起主导作用的损伤机理.将激光作用时杂质吸收的热学和力学过程与杂质分布的统计规律结合起来,得到了深埋于薄膜内部的杂质诱导薄膜损伤概率与杂质密度、激光功率密度以及薄膜厚度的关系.该模型认为能诱导薄膜破坏的杂质尺寸范围与杂质填埋深度有关,所以不同深度处能诱导薄膜损伤的杂质密度不一样,理论结果与实验结果符合得很好.该理论模型还可以很好地解释损伤形貌.  相似文献   

9.
本文给出了HL-1托卡马克在通常欧姆放电和偏压诱发H模放电条件下,脉冲注入杂质气体的实验结果以及对杂质在通常欧姆等离子体和偏压诱发H模等离子体中的输运研究结果。实验结果表明,在HL-1上偏压诱发H模等离子体中对杂质的约束性能明显优于在通常欧姆等离子体中对杂质的约束性能。杂质输运的数值模拟结果说明,无论在通常欧姆等离子体中,还是在偏压诱发H模等离子体中,杂质的输运系数都比新经典理论预计的要大得多,输运是反常的。在偏压诱发的H模等离子体中引入杂质输运“位阱”概念,能够对杂质离子约束时间长的实验现象进行很好的描述。合理地解释了在偏压杂质注入实验中杂质辐射上升时间长、衰减慢的现象。  相似文献   

10.
1、前言 对于半导体中深杂质能级的研究,近年来又重新活跃起来了。尤其是GaAs、GaP等发光材料中的深杂质能级,它决定发光效率的老化特性,对器件应用也很重要。同时由于深杂质能级同晶体缺陷(主要是点缺陷)之间有关系,也是表征晶体质量的参数之一。相对过去只用浅杂质浓度和迁移率来评价晶体的电学特性来说,深杂质能级的测定将会成为今后估价晶体的有力手段,因此,有必要建立可靠而简单的测量方法。 有关深杂质能级的理论研究固体物理领域中很早就进行过,但也有很多不清楚的地方。特别是有关半导体中陷阱中心的量子力学性质还很不清楚。目前还没有关于某些中心是发光还是非发光的理论论述。有关陷阱的中心理论是五十年代碱卤化物中的色心特性,特别是关于  相似文献   

11.
黄旭初 《中国物理 B》2017,26(3):37501-037501
An exact solution of a single impurity model is hard to derive since it breaks translation invariance symmetry. We present the exact solution of the spin-1/2 transverse Ising chain imbedded by a spin-1 impurity. Using the hole decomposition scheme, we exactly solve the spin-1 impurity in two subspaces which are generated by a conserved hole operator.The impurity enlarges the energy deformation of the ground state above a pure transverse Ising system without impurity.The specific heat coefficient shows a small anomaly at low temperature for finite size. This indicates that the impurity can tune the ground state from a magnetic impurity space to a non-magnetic impurity space, which only exists for spin-1impurity comparing with spin-1/2 impurity and a pure transverse Ising chain without impurity. These behaviors essentially come from adding impurity freedom, which induces a competition between hole and fermion excitation depending on the coupling strength with its neighbor and the single-ion anisotropy.  相似文献   

12.
With the use of variational method to solve the effective mass equation, we have studied the electronic and shallow impurity states in semiconductor heterostructures under an applied electric field. The electron energy levels are calculated exactly and the impurity binding energies are calculated with the variational approach. It is found that the behaviors of electronic and shallow impurity states in heterostructures under an applied electric field are analogous to that of quantum wells. Our results show that with the increasing strength of electric field, the electron confinement energies increase, and the impurity binding energy increases also when the impurity is on the surface, while the impurity binding energy increases at first, to a peak value, then decreases to a value which is related to the impurity position when the impurity is away from the surface. In the absence of electric field, the result tends to the Levine's ground state energy (-1/4 effective Rydberg) when the impurity is on the surface, and the ground impurity binding energy tends to that in the bulk when the impurity is far away from the surface. The dependence of the impurity binding energy on the impurity position for different electric field is also discussed.  相似文献   

13.
The quasi-stationary profiles of the impurity ionization stages in HT-6B Tokamak were absolutely determined by monitoring the VUV and visible line emissions. An impurity transport code was set up. The impurity transport coefficients and other parameters about impurities were determined. From the changes of impurity emission profiles, it was concluded that the impurity confinement was improved and the impurity recycling was reduced by the slow magnetic compression along the minor radius. Some characteristics about the impurity transport in this small device are discussed.  相似文献   

14.
董丽娟  江海涛  杨成全  石云龙 《光子学报》2007,36(12):2248-2251
采用转移矩阵的方法研究了含单负材料的一维光子晶体中掺入双层正常材料杂质时杂质模频率的变化问题.研究结果表明,杂质模频率与晶格常量的标度无关,且对晶格常量的涨落很不敏感.同时,通过增加杂质层厚度及层数发现,杂质模频率随之减小,而它的变化率随之增加,且杂质模消失在低频带边的速度会越来越快.  相似文献   

15.
We study optically‐induced collective excitations of graphene in the presence of a strong perpendicular magnetic field and a single impurity. We determine the energies and absorption strengths of these excitations, which become localised on the impurity. Two different types of impurity are considered i. the long‐range Coulomb impurity, ii. a δ‐function impurity located at either an A or B graphene sublattice site. Both impurity types result in some bound states appearing both above and below the magnetoplasmon continuum, although the effect of the short‐range impurity is less pronounced. The dependence of the energies and oscillator strengths of the bound states on the filling factor is investigated.  相似文献   

16.
17.
Interaction potentials between point defects, vacancy-vacancy, vacancy-Zn impurity, vacancy-Mg impurity, Zn impurity-Mg impurity, Zn impurity-Zn and Mg impurity-Mg impurity, have been calculated in aluminum.  相似文献   

18.
汪洁英  曾建中 《物理学报》1984,33(10):1393-1400
本文将单点杂质引入到不可共度势一维体系中,用格林函数方法推导了杂质状态的能级和波函数。发现当杂质处在不可共度势变化较快的位置时,杂质能级的变化也较大。杂质状态的波函数是略有波动的指数衰减函数。讨论了杂质对带内状态波函数的影响,发现以杂质点为对称的体系中,具有偶宇称的状态波函数,在杂质的附近,振幅有相当大的下降。在对杂质点无对称性的体系中,在杂质的附近,产生一个振幅的阶跃。 关键词:  相似文献   

19.
在HL-lM装置上利用激光吹气技术,在等离子体边缘瞬态注入少量Al杂质粒子,通过对真空紫外光谱和软X射线区的杂质辐射测量,分别研究了欧姆等离子体和低杂波电流驱动等离子体两种情况下,Al杂质粒子输运与约束特性。结果表明:在欧姆等离子体和低杂波电流驱动等离子体两种情况下,等离子体中心区,在没有MHD锯齿震荡和有MHD锯齿震荡非锯齿破裂期间,杂质粒子输运基本上受新经典规律支配;在有MHD锯齿震荡锯齿破裂期间,杂质粒子输运受MHD不稳定性支配,但其时间很短(通常小于300μs),所以在这种情况下,杂质粒子输运的平均效应比新经典值稍大。而约束区杂质粒子输运则比新经典的值大很多,是反常的。在一定条件下低混杂波电流驱动可以改善等离子体粒子约束。  相似文献   

20.
The migration of an impurity atom on the surface of a solid initiated by the diffusion of vacancies was studied theoretically. With multiple collisions of a separate impurity with vacancies taken into account, impurity movements became Brownian, and the mean-square displacement at long times became proportional to time. An analytic equation for the diffusion coefficient was obtained. The equation only differed by a factor from the product of the impurity diffusion coefficient by impurity concentration  相似文献   

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