436 resultados para SB


Relevância:

20.00% 20.00%

Publicador:

Resumo:

利用在束γ谱学方法,通过~(124)Sn(~7Li,α2n)反应研究了~(125)Sb的激发态,首次建立了~(125)Sb的高自旋能级纲图,其中包括21条新γ跃迁和14个新能级。发现1970,2110和2470 keV3个能级为同质异能态,基于延迟符合测量确定了它们的寿命范围,并确定其自旋、宇称分别为15/2~-,19/2~-和23/2~+。根据粒子-核芯耦合图像和经验壳模型计算解释了~(125)Sb的能级结构,3个同质异能态的组态分别被指定为πg_(7/2)(×)V(h_(11/2)s_(1/2))_(5~-),πg_(7/2)(×)V(h_(11/2)d_(3/2))_(7~-)和πg_(7/2)(×)V(h_(11/2)~2)_(10~+),

Relevância:

20.00% 20.00%

Publicador:

Resumo:

利用在束γ谱学方法 ,通过1 2 4 Sn( 7Li,α2n)反应首次研究了丰中子核1 2 5Sb的高自旋态 .建立了自旋达 2 3 2 +、激发能至 2 63 7keV的能级纲图 ,其中包括 2 1条新γ跃迁和 1 4个新能级 .在 1 970 ,2 1 1 0和 2 471keV识别出了 3个同质异能态 ,估计了它们的寿命范围 ,并建议分别具有πg7 2 ν(h1 1 2 s1 2 ) ,πg7 2 ν(h1 1 2 d3 2 ) ,πg7 2 ν(h21 1 2 )三准粒子组态 .根据价质子与1 2 4 Sn核芯激发态的耦合讨论了1 2 5Sb的能级结构 .

Relevância:

20.00% 20.00%

Publicador:

Resumo:

土壤中重金属的解吸直接影响重金属在环境中的形态转化和植物有效性。文章以我国东北地区草甸棕壤作为研究对象,通过对Sn、Hg、Sb、Bi单一及复合污染土壤中Sn、Hg、Sb、Bi的解吸动力学行为的研究,探索污染土壤中重金属Sn、Hg、Sb、Bi的解吸特性与规律。结果表明,不同污染类型的污染土壤中Sn、Hg、Sb、Bi这几种重金属的解吸量随着振荡时间的延长而不断增加。重金属Sn、Hg、Sb、Bi的解吸过程可分为快速反应阶段和慢速反应阶段。描述土壤Sn、Hg、Sb、Bi解吸动力学过程的最优模型为Elovich方程,其次为双常数方程,而一级动力学方程拟合效果不佳。此外,污染土壤中重金属Sn、Hg、Sb、Bi的解吸过程受共存重金属元素的影响。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The energy band structures of LaX(X=N, P, As, Sb) crystals have been studied by using LMTO-ASA method. The calculated energy gaps of these crystals are 2. 30 eV for LaN, 2. 05 eV for LaP, 1. 66 eV for LaAs and 1. 34 eV for LaSb. The results are in good agreement with experimental data, At the same time, using these calculated results of energy band structures of these crystals, the chemical bond properties have been analyzed and calculated, The covalency values of these crystals are 26.15% for LaN, 32.54% for LaP, 33.30% for LaAs and 36.49% for LaSb, which agree satisfactorily with the calculated ones by using PV (Phillips-Vechten) theory.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

用LMTO-ASA能带程序计算了LaX(X=N,P,As,Sb)晶体的能带结构,得到的晶体能隙分别为LaN2.30eV,LaP2.05eV,LaAs1.66eV,LaSb1.34eV,与实验结果基本相符.利用价电子总数在阴阳离子上的分配数之比,给出计算晶体化学键性质的经验关系式,根据该式计算晶体化学键的共价性与文献结果非常吻合,说明了该关系式的合理性

Relevância:

20.00% 20.00%

Publicador:

Resumo:

以Philips-VanVechten理论和晶体光学性质为基础,计算了LaX(X=N,P,As,Sb)晶体的离子半径(单位:nm):(La:N)为(0.1414,0.1236),(La:P)为(0.1518,0.1489),(La:As)为(0.1536,0.1526),(La:Sb)为(0.1586,0.1651).用LMTO-ASA方法对LaX系列晶体的能带结构进行了计算.所得到的能隙是:LaN为2.30eV,LaP为2.05eV,LaAs为1.66eV,LaSb为1.34eV.与实验结果相符.这也证明了作者得到的半径的合理性.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

By using Pillips and van Vechten theory, the chemical bond parameters and dielectric constants of REM (RE=rare earth, M=N, P, As, Sb) crystals were calculated. The values calculated of dielectric constants agree with the experimental values.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

利用Philips和VanVechten理论计算了稀土REM(M=N、P、As、Sb)晶体的化学键参数和介电常数,ε的计算结果和已知的实验值符合很好。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

With XRD, R- T curves, and a.c chi measurements, the doping and codoping effects of Sb and V to a Cu-deficient Pb-doped Bi system have been studied. A sample singly doped with V possesses a T(c) about 2 K lower than that of a sample singly doped with Sb. This is attributed to the different sites of their substitution. It was observed that for promoting 2223 phase formation, Sb and V works cooperatively, and the codoping of Sb may enhance the 2223 phase formed. With a low doping level of Sb, the optimum doping amount of V is 0.3, i.e., with a nominal composition of Bi1.5Pb0.3Sb0.06Sr2Ca2Cu2.4V0.3Oy. A sample in which the 2223 phase is the dominant phase and which has a zero resistance transition temperature of 105 K has been obtained.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

本文研究了单掺(Sm~(3+),Ce~(3+)、Gd~(3+).Sb~(3+)、双掺(Sm~(3+)+Ce~(3+)、Sm~(3+)+Gd~(3+),Sm~(3+)+Sb~(3+))和兰掺(Sm~(3+)+Gd~(3+)+Ce~(3+))约四十余种不同玻璃的发射谱和激发谱.探讨了玻璃成份和掺杂离子浓度对Sm~(3+)发光性质的影响以及Ce~(3+),Gd~(3+)、Sb~(3+)、Ce~(3+)+Gd~(3+)对Sm~(3+)的敏化作用。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

考察了不同组成的V-Sb-O系复合氧化物对丙烷氨氧化的催化活性.用XRD研究了催化剂的结构,利用程序升温方法研究了催化剂中氧的活动性和表面酸碱性,讨论了催化剂体相和表面结构与催化性能间的关系.结果表明,VSbO_4和Sb_2O_4间的协同作用是影响催化活性的重要因素.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

本文研究了掺杂Sb、S_n及Cd的In_2O_3的电性质,并与纯的In_2O_3进行比较,得到一些有意义的结果。IO的电导率及载流子浓度主要由氧缺位所致;ITO和ISO的电导率和载流子浓度,主要由掺杂元素所致;掺Sn的电导率、载流子浓度和迁移率高于掺Sb,其原因在于在同样掺杂浓度的条件下,ITO中的中性杂质浓度低于ISO及掺Sn后使电子离域程度增大。在掺Cd浓度高时,随着Cd浓度增加,电导率和载流子浓度均降低。