BeⅡ内壳激发态的能量,电离势和辐射波长

采用截断变化方法计算了ＢｅⅡ内壳激发Ｉｓ２ｐｎ（ｎ＝２－４,ｌ＝０－３）＾２Ｌ态的能量,电离势和辐射波长。相对论效应计算到一级微扰,质量极化效应计算到无突级。这些能量和辐射波长的计算结果与其它实验和理论结果相比较,符合得很好。     

2,4—二氨基—1,3—环丁烷二酮分子的二阶超极化率和电子相关效应

在６－３１Ｇ＊＊水平上优化了２,４－二氨基－１,３－环丁烷二酮（ＮＤＱ）的分子构型,并计算了振动频率。分别用有限场方法（ＦＦ）及耦合微扰方法（ＣＰＨＦ）在ａｂ ｉｎｉｔｉｏ／４－３１Ｇ＋ｐｂ／ｐ水平上计算值较ＲＨＦ增大９％和７８％。用三态模型对计算结果进行了分析。     

5-溴水杨基荧光酮-溴化十六烷基三甲铵荧光熄灭法测定微量钼的研究

本文报道了在溴化十六烷基三甲铵（ＣＴＭＡＢ）存在下,以５－溴水杨基荧光酮（５－ＢｒＳＡＦ）作为荧光试剂,用荧光熄灭法测定微量钼的新方法。详细研究了各种条件实验。反应的适宜酸度范围为 ０．０８－０．２４ｍ ｏｌ·Ｌ－ １ ＨＣｌ,钼含量在０－ ４．０μｇ／２５ｍ Ｌ范围内呈线性关系,配合物的组成比为Ｍｏ（Ⅵ）∶５－ＢｒＳＡＦ∶ＣＴＭＡＢ＝ １∶２∶２,激发波长为３６５ｎｍ ,发射波长为５２５ｎｍ 。方法灵敏度高,检出限为２．０μｇ／Ｌ。用于样品中微量钼的测定,结果令人满意。     

2—溴甲基萘荧光和室温磷光性质研究

研究了２－溴甲基萘（２－ＢｒＭＮ）的荧光及磷光性质。２－溴甲基萘是一种优良的荧光试剂,λｅｘ／λｅｍ＝２７４／３３４ｎｍ,其浓度在１．０×１０＾－６～１．２×１０＾－４ｍｏｌ·Ｌ＾－１范围内与荧光强度呈良好的线性关系,相关系数ｒ＝０．９９９,最低检测限为４．７×１０＾－８ｍｏｌ·Ｌ＾－１。以β－环糊精（β－ＣＤ）作保护剂和１,２－二溴丙烷（ＤＢＰ）为重原子微扰剂的２－ＢｒＭＮ／β－ＣＤ／ＤＢＰ体系     

5—溴水杨基荧光酮—溴化十六烷基三甲铵荧光熄灭法测定微量？…

本文报道了在溴化十六烷基三甲铵（ＣＴＭＡＢ）存在下,以５－溴水杨基荧光酮（５－ＢrＳＡＦ）作为荧光试剂,用荧光熄灭法测定微量钼的新方法。详细研究了各种条件实验。 反应了适宜酸度范围为０．０８－０．２４ｍｏｌ．Ｌ＾－１ＨＣ１,钼含量在０－４．０ｕｇ／２５ｍＬ范围内呈线性关系,配合物的组成比为Ｍo（Ⅳ）：５－ＢrＳＡＦ：ＣＴＭＡＢ＝１：２：２,激发波长为３６５ｎｍ,发射波长为５２５ｎｍ。方法灵敏度高,检出     

稀磁半导体Cd_（1－x）Fe_xTe的磁光光谱

在７０－３００Ｋ温度范围内测量了组分ｘ为０．０１和０．０４的Ｃｄ１－ｘＦｅｘＴｅ及ＣｄＴｅ的法拉第效应随入射光子能量的变化，首次获得了Ｃｄ１－ｘＦｅｘＴｅ在布里渊区Γ点和Ｌ点的有效ｇ因子及其与温度的关系。给出了Ｆｅ２＋离子与载流子间的ｓｐ－ｄ交换作用常数Ｎ０（β－α）＝（－１．５７±０．０３）ｅＶ。     

Tm^3＋掺杂的MFT玻璃上转换发光及光学增益

报道了一种新型ＭＦＴ（Ｍｕｌｔｉ－Ｆｌｕｏｒｉｄｅ－Ｔｅｌｌｕｒｉｄｅ）玻璃材料（组份为５０ＴｅＯ２－１９．７ＰｂＦ２－１０ＡｌＦ３－１０ＢａＦ－０．３Ｔｍ２Ｏ３）的制备方法,测量了６５０ｎｍ激发下Ｔｍ＾３＋离子掺杂在ＭＦＴ玻璃材料中源于＾１Ｄ２→＾３Ｈ６（４７６ｎｍ）跃迁的两组蓝色上转换发光研究了上转换发光强度随激光率的变化关系,并且首次应用ＡＳＥ（Ａｍｐｌｉｆｉｅｄ Ｓｐｏｎｔａｎｅｏｕｓ Ｅ     

EuBa2Cu3O7的化学键性质和穆斯堡尔谱研究

利用电介质的平均能带模型计算了ＥｕＢａ２Ｃｕ３Ｏ７的化学键参数,得到Ｃｕ（１）－Ｏ键的平均共价性为０．４１４,Ｃｕ（２）－Ｏ键的平均共价性为０．２８１,应用由共价性和极化率定义的化学环境因子计算了＾５７Ｆｅ、＾１１９Ｓｎ在ＥｕＢａ２Ｃｕ３Ｏ７中的穆斯堡尔同质异能位移,确定了＾５７Ｆｅ、＾１１９Ｓｎ的价态和占位情况。     

电子自金属电极向Fe^3＋（H2O）6离子转移的几率

用微扰法计算了电子自金属电极向Ｆｅ３＋（Ｈ２Ｏ）６离子转移的几率，其中，利用了Ｆｅ２＋离子３ｄ态被六个配位水分子微扰后的波函数。     

BaZn2(GeMn)0-2Fe15-6O27六角铁氧体的磁晶各向异性

用标准陶瓷工艺制备了ＢａＺｎ２（ＧｅＭｎ）０－２Ｆｅ１５－６Ｏ２７六角铁氧体．假设Ｇｅ４＋取代了４ｅ和４ｆⅣ中的Ｆｅ３＋,能够很好地解释实验结果．利用分子场理论和Ｈ．Ｂ．Ｃａｌｌｅｎ单离子各向异性模型计算了ＢａＺｎ２（ＧｅＭｎ）０－２Ｆｅ１５－６Ｏ２７次点阵之间的交换参数和各次点阵对磁晶各向异性的贡献,并对实验结果进行了拟合．结果表明,１２ｋ和２ｄ次点阵对磁晶各向异性有较大的贡献 关键词：     

(ZnSe)_(12)在外电场下的基态性质和激发特性研究

以SBKJC为基组,采用密度泛函PBE0方法研究了不同外电场(0-0.030 a.u.)对(ZnSe)_(12)的基态几何结构、电荷分布、能量、电偶极矩、能隙、最小振动频率的影响;继而采用含时的TD-PBE0方法研究了(ZnSe)_(12)在外电场下的激发特性,并模拟了紫外-可见光谱.研究结果表明:外电场的加入导致分子对称性降低,当电场从0 a.u.变化到0.030 a.u.时,偶极矩逐渐增加,体系总能量、最小谐振频率和能隙一直减小.外电场对(ZnSe)_(12)的激发特性影响较大,随着电场的增加,紫外-可见光谱发生红移,同时对振子强度有很大影响,原来振子强度不为零的激发态变弱或成为禁阻跃迁,而原来振子强度很弱或禁阻的激发态变得很强.可以通过改变外电场来改变(ZnSe)_(12)的基态性质,以及控制(ZnSe)_(12)的吸收和发光特性.     

Electron field emission properties of conducting polymer coated multi walled carbon nanotubes

The present work describes the field emission characteristics of conducting polymer coated multi walled carbon nanotubes (MWNTs) field emitters fabricated over flexible graphitized carbon cloth. Nanocomposites involving the combination of MWNTs and conducting polymers polyaniline (PANI) and polypyrrole (PPy) have been prepared by in-situ polymerization method and have been characterized using scanning electron microscopy and transmission electron microscopy. Using spin coating method, field emitters based on PANI/MWNTs and PPy/MWNTs over flexible graphitized carbon cloth have been prepared. The field emission characteristics have been studied using an indigenously fabricated set up in a vacuum chamber with a base pressure of 2 × 10⁻⁵ Pa and the results are discussed. Our results display that the field emission performance of the emitters depends strongly on the work function of the emitting material. Low turn on emission field of 2.12 V/μm at 10 μA/cm² and high emission current density of 1 mA/cm² at 3.04 V/μm have been observed for PANI/MWNTs field emitter.     

椭球坐标下求解强磁场中的氢原子

在椭球坐标系下,采用B样条基组方法计算了磁场范围在0-1000 a.u.下氢原子低能态能量以及实验室磁场下(几个特斯拉)氢原子里德堡态的能级,并与文献中的精确结果进行了比较.对1s0态,磁场γ≤100 a.u.时,本文计算结果有12位有效数字的精度,γ=1000 a.u.时有11位有效数字的精度.对2p-1低激发态,γ≤100 a.u.时,能量至少有11位有效数字的精度;γ=1000 a.u.时,有9位有效数字的精度.对原子高激发态,我们计算了实验室磁场下(磁场为4.7特斯拉)氢原子里德堡态(主量子数n=23)的抗磁谱,得到了至少10位有效数字精度的能谱.本文方法既适用于超强磁场下低能态的计算,同样适合原子高里德堡态抗磁谱的计算,为精确计算强磁场下原子能谱提供了一个新的可行方案.此外,讨论了本文方法推广到平行及交叉电磁场下原子能谱计算的可行性.     

硼球烯B_(40)在外电场下的基态性质和光谱特性

以6-31G*为基组,采用密度泛函PBE0方法研究了不同外电场(0—0.060 a.u.)对硼球烯B_(40)的基态几何结构、电荷分布、能量、电偶极矩、能隙、红外及拉曼光谱特性的影响;继而采用含时的TD-PBE0方法研究了硼球烯B_(40)在外电场下的电子光谱.研究结果表明:外电场的加入导致分子对称性降低,当电场从0 a.u.变化到0.060 a.u.时,偶极矩逐渐增加,体系总能量和能隙一直减小;外电场的加入将改变红外和拉曼光谱特征,如谐振频率的移动以及红外和拉曼峰的增强或减弱;外电场对硼球烯B_(40)的电子光谱影响较大,当电场从0 a.u.变化到0.060 a.u.时,电子光谱发生红移,同时对振子强度有很大影响,原来振子强度最强的激发态变弱或成为禁阻跃迁,而原来振子强度很弱或禁阻的激发态变得最强.可以通过改变外电场来改变B_(40)的基态性质,以及控制B_(40)的光谱特性.     

基于密度泛函理论的外电场下C_3F_8微观特性的研究

全氟丙烷(C_3F_8)作为一种拥有较低温室效应的SF_6替代气体,被国内外学者广泛研究.为了从分子层面上揭示全氟丙烷在外电场作用下微观特性的变化情况,采用密度泛函理论中的M06-2X方法,在6-31G(d)基组水平上优化得到了C_3F_8的基态稳定构型.分析了不同外电场(0-0.020 a.u.)对C_3F_8分子的结构、Highest Occupied Molecular(HOMO)、Lowest Unoccupied Molecular(LUMO)、能隙、键级的影响,并研究了全氟丙烷分子的激发态能、波长、振子强度.结果表明,在所加电场范围内,随着电场强度的增大,C_3F_8分子最高占据轨道能级逐渐增大,最低空轨道能级逐渐减小,能隙E_G逐渐减小, C_3F_8分子的化学活性增强;C_3F_8分子中的C-C键的Mayer Bond Order (MBO)值随电场强度的增大均出现增大的情况,分子的稳定性降低;C_3F_8分子激发态的激发能总体上呈现出减小的趋势,激发态的波长总体上则呈现出增大的趋势,表明在外电场的作用下,全氟丙烷分子变得越来越容易激发.     

环境温度对纳米磁流体场诱导光学双折射的影响

在20~80 ℃温度范围内,研究了两种浓度的铁氧体(主要成分为Fe3O4)磁流体在一系列固定磁场强度(场强范围为0~200 mT)下的双折射与温度的关系.结果表明不同浓度磁流体的双折射具有类似的磁场和温度依赖性.固定磁场强度时,磁流体的双折射值与温度成反比|而温度恒定时,磁流体的双折射值与外磁场的强度成正比|在相同磁场强度、恒定温度下,高浓度磁流体的双折射值比低浓度磁流体的大.详细分析了实验结果,并深入讨论了磁流体双折射的温度、场强和浓度依赖性的物理机理.     

Hydrogen atom in strong magnetic field: a high accurate calculation in spheroidal coordinates

A B-spline-type basis set method for the calculation of hydrogen atom in strong magnetic fields in the frame of spheroidal coordinates has been introduced. High accurate energy levels of hydrogen in the magnetic field, with strength ranging from 0 to 1000 a.u., have been obtained. For the ground state, 1s₀, energies with at least 11 significant digits have been obtained. For the low-lying excited state, 2p₋₁, energies with at least 9 significant digits are obtained. The method has also been applied to the calculation of hydrogen Rydberg states in laboratory magnetic fields. Energy spectra with at least 10 significant digits are presented. A comparison with other results in the literatures has been performed. Our results are comparable to the most accurate one up to date. A possible extension to the cases of parallel and crossed electric and magnetic fields have been discussed.     

Synthesis and field emission properties of GaN nanowires

Gallium nitride (GaN) nanowires grown on nickel-coated n-type Si (1 0 0) substrates have been synthesized using chemical vapor deposition (CVD), and the field emission properties of GaN nanowires have been studied. The results show that (1) the grown GaN nanowires, which have diameters in the range of 50-100 nm and lengths of several micrometers, are uniformly distributed on Si substrates. The characteristics of the grown GaN nanowires have been investigated using X-ray diffraction (XRD) and transmission electron microscopy (TEM), and through these investigations it was found that the GaN nanowires are of a good crystalline quality (2) When the emission current density is 100 μA/cm², the necessary electric field is an open electric field of around 9.1 V/μm (at room temperature). The field enhancement factor is ∼730. The field emission properties of GaN nanowires films are related both to the surface roughness and the density of the nanowires in the film.     

应用圆二色光谱研究电场对脂肪酶二级结构的影响

脂肪酶被不同强度的电场处理5 min,用圆二色光谱(circular dichroism, CD)研究电场对脂肪酶(Lipase)二级结构的影响。研究结果表明：在0.5～6.0 kV·cm-1范围内,不同强度的电场对脂肪酶的α-螺旋、β-折叠、β-转角及无规卷曲相对含量的影响程度不同。随场强的增加,各二级结构单元含量呈非单调变化。电场作用可使脂肪酶二级结构中α-螺旋、β-折叠、β-转角及无规卷曲发生转化。总体上,电场使脂肪酶的二级结构由α-螺旋、β-折叠向转角及无规卷曲转化。α-螺旋含量和β-折叠的含量降低幅度分别为4.6%～48.0%和13.2%～35.1%,β-转角含量与无规卷曲含量增加幅度分别为2.8%～33.3%和0.9%～48.1%。文章结果对研究电场处理植物种子的宏观生物效应作用机理提供了重要理论依据。     

Energy,force and field strength in a system of two charged conducting balls

A calculation has been performed for the interaction force and the field strength in a system consisting of two charged conducting balls in three cases: 1) the balls are maintained at the preset potentials; 2) the balls are insulated and have fixed charges; 3) one of the balls has the preset potential, and the second one has the preset charge. Experimental measurements of forces in the first and third cases were performed and fair agreement with calculations was confirmed. A calculation method has been suggested, and the electric field strength on the nearest poles of the balls has been calculated for the three mentioned cases. A good agreement with the other authors' calculation results has been demonstrated.