3 d sMa x软件下的3 D物理模型

物理学是科学的世界观和方法论的基础, 物理模型可以简化物理问题, 直达问题本质. 文章介绍了什么 是3 D物理模型, 通过理论分析3 D物理模型的重要性, 展示3 D效果所带来的教学结果, 来说明3 D物理模型的重要 性和历史发展的必然性. 同时通过3 d sMa x软件, 介绍成熟的3 D物理模型及给出实例介绍3 D的建立过程, 说明其 应用于物理教学的可行性和必要性. 希望可以开发更为成熟的3 D教学软件     

Synthesis and physicochemical properties of Li2 Me x Zr1 − x O3 − δ (Me = Nb,Ti; x = 0.05, 0.1) solid solutions

Complex lithium metallates Li₂ Me _x Zr_{1 ? x} O_{3 ? δ} (Me = Nb, Ti, x = 0.05, 0.1) with iso-and heterovalent substitutions for Zr⁴⁺ ions in lithium zirconate are synthesized for the first time using a citrate technique. The inclusion of Ti⁴⁺ and Nb⁵⁺ ions in the crystal structure of Li₂ZrO₃ is confirmed by means of X-ray diffraction and NMR. It is shown that in the temperature range of 750–820 K, Li₂Ti_0.1Zr_0.9O₃ solid solution has higher conductivity than phases of undoped lithium zirconate.     

Electrical and magnetic properties of La0.67Ba0.33Mn1−x (Me) x O3 perovskite manganites: case of manganese substituted by trivalent (Me = Cr) and tetravalent (Me = Ti) elements

The effects of non-magnetic Ti⁴⁺ substitution on the structural, electrical and magnetic properties of La_0.67Ba_0.33Mn_1?x Ti _x O₃ (0≤x≤0.1) are investigated and compared to those existing in La_0.67Ba_0.33Mn_1?x Cr _x O₃ (magnetic Cr³⁺). The structural refinement by the Rietveld method revealed that Ti-doped samples crystallize in the cubic lattice with space group $\mathrm{Pm}\bar{3}\mathrm{m}$ , while samples with Cr crystallize in the hexagonal setting of the rhombohedral $\mathrm{R}\bar{3}\mathrm{C}$ space group for identical contents of dopant. The most relevant structural features are an increase of the lattice parameters, of the cell volume and of the inter-ionic distances with increasing Ti doping level. Both series of samples show a decrease of the paramagnetic–ferromagnetic transition temperature when the amount of chromium or titanium increases. Transport measurements show that when increasing the metal doping, the resistivity increases whereas the metallic behavior of the parent compound La_0.67Ba_0.33MnO₃ is destroyed. For a substitution higher than 5 at.% of Ti and 10 at.% of Cr, the samples exhibit a semiconducting behavior in the whole range of temperature, for which the electronic transport can be explained by variable range hopping and/or small polaron hopping models.     

Features of the structure and dynamics of Me1−x (NH4) x SCN (Me = K, Rb) mixed crystals

Neutron scattering is used to study the structure and dynamics of Me_{1 − x} (NH₄) _x SCN (Me = K, Rb) mixed crystals along the concentration section of 0.0 < x < 1.0 at room temperature 10 and 290 K. Phase transitions in Me_{1 − x} (NH₄) _x SCN mixed crystals are analyzed by neutron powder diffraction. The measured spectra of inelastic incoherent neutron scattering from mixed crystals in a concentration range of 0.0 < x < 1.0 at 10 are transformed into the generalized phonon density of states G(E) in the one-phonon incoherent approximation. Using G(E), we determine the changes in ammonium ion dynamics during phase transitions. Low energy resonance and local translational (two bands) and librational (two bands) modes are observed in the disordered rhombic phase at 10 K. The low energy resonance mode is not found in the ordered monoclinic phase at 10 K, though the local translational mode in the form of two bands and the local librational mode in the form of four bands are present there. The low energy resonance mode appears due to hybridization of the phonon spectrum of the host crystal with rotational tunneling modes of the split librational ground state of the impurity’s molecular ammonium ion.     

ВЛИЯНИЕ СОДЕРЖАНИЯ К ИСЛОРОДА НА ЭЛЕКТРИЧЕСКИЕ И ТЕ РМОЭЛЕКТРИЧЕСКИЕ СВОЙСТВА ТРОЙНОЙ СИС ТЕМЫ Вi2Те3−x Sе x

, Bi₂Te_3–x Se _x . , , . , , . .

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Influence of oxygen content on electric and thermoelectric properties of ternary system Bi₂Te_3–x Se _x

A study is made of the influence of oxygen, contained in the semi-conducting system Bi₂Te_3–x Sé _x , on the electric and thermoelectric properties. It is shown that the addition of oxygen to the prepared samples Bi₂Te_2.4Se_0.6 causes a decrease in electric conductivity while the thermoelectric force remains unchanged. This influence is connected with a decrease in the mobility of the electrons but their concentration is not influenced by the presence of oxygen. Conclusions are reached as to the influence of oxygen on the efficiency of the conversion of thermal energy into electric energy and vice versa.

     

Electro-optic effect in SrTiO3 and Sr1–x Ca x TiO3 (x = 0.014)

The results of the investigation of the quadratic electro-optic effect in Sr_1–x Ca _x TiO₃ with x = 0.014 (SCT) and in nominally pure SrTiO₃ (STO) at room temperature in applied direct-current (dc) and alternating-current (ac) electric fields have been presented. It has been shown that the quadratic (in polarization) electro-optic coefficients of STO and SCT crystals coincide within the accuracy of the determination (±5%). It has been found that, in nominally pure STO measured in a dc electric field, there is a relaxation of the electro-optic effect with a relaxation time τ ≈ 30 s due to the formation of a space charge in the sample. No similar effect in SCT has been observed. A possible mechanism for the formation of a space charge in STO and SCT has been discussed.     

Mo(d,x)95mTc,Mo(d,x)96gTc和Mo(d,x)97mTc反应的激发函数

用活化法和迭靶技术,测量了入射氘核能量从3.2到13.3MeV范围内,Mo(d,x)^95mTc,Mo(d,x)^96gTc和Mo(d,x)^97mTc反应的激发函数,并与复合核统计模型理论计算作了比较.     

x3振荡器的周期运动

给出了回复力Ｆ与位移ｘ的三次方成正比的“ｘ＾３振荡器”周期运动的解析解，并证明其振荡周期夺幅成反比。     

Critical gravities in d ≥ 3

Critical gravities originated in the context of three-dimensional massive gravities. They were conjectured to describe gravitational duals of two-dimensional logarithmic conformal field theories. In this talk, we show that critical gravities can also be studied in dimensions d > 3. As in three dimensions, higher-dimensional critical gravities exhibit logarithmic modes. We argue that the existence of these logarithmic modes leads one to conjecture that higher-dimensional critical gravities are dual to logarithmic conformal field theories in more than two dimensions.     

40≤Z≤44类镍离子3d94s,3d94p,3d94d组态s-p,p-d跃迁的计算

用多组态自洽场方法,结合我们提出的半经验拟合公式,对40≤Z≤44类镍离子3d94s,3d94p,3d94d态的能级进行计算,根据能级拟合值算出s-p,p-d跃迁的谱线波长,并给出各谱线的HFR振子强度.     

Mo(d,x)~(95m)Tc,Mo(d,x)~(96g),Tc和Mo(d,x)~(97)Tc反应的激发函数

用活化法和迭靶技术,测量了入射氘核能量从3.2到13.3MeV范围内,Mo(d,x)~(95m)Tc,Mo(d,x)~(96g)Tc和Mo(d,x)~(97m)Tc反应的激发函数,并与复合核统计模型理论计算作了比较。     

Microscopic description of the reactions d + d → p + 3H and d + d → n + 3He at low energies

A collective adiabatic approach is used to explore the total and differential cross sections for the reactions d + d → p + ³H and d + d → n + ³He at incident-deuteron energies of up to 6 MeV. All substantially contributing partial waves of order not higher than that of G waves are taken into account. The experimental value of the difference of the cross sections for the above mirror reactions is reproduced theoretically under the assumption that nuclear forces obey the condition of isotopic invariance. The positions and amplitudes of the maxima in the calculated total cross sections virtually coincide with those of the corresponding experimental values. It is shown that, around the maxima of the cross sections under study, dominant contributions to them come from the P wave. The sensitivity of observables to the parameters of nucleon-nucleon interaction is analyzed.     

类钴Pd19+离子3p63d9-3p53d10,3p63d9-3p83d84p跃迁的计算

用多组态自洽场方法,结合我们提出的半经验拟合公式,计算了高离化态类钴Pd19+离子3p63d9-3p53d10,3p63d9-3p83d84p跃迁和振子强度,并与实验符合得较好。     

类钴Rh18+离子3P63d9-3P53d10,3P63d9-3P63d84p跃迁的计算

用多组态自洽场方法，结合提出的半经验拟合公式，计算了高离化态类钴Rh^18 离子3p^63d^9—3p^53d^10，3p^63d^9—3p^63d^84p跃迁和振子强度，并与实验进行了比较．     

ZnⅩⅨ离子3d2-3p3d跃迁的多组态相对论理论计算

用多组态相对论理论对ZnⅩⅨ离子3s2,3s3p,3p2,3s3d,3p3d,3d2,3s4s,3s4p,3s4f组态能级结构进行了计算与分析.在已有实验工作的基础上,运用参数拟合方法计算了ZnⅩⅨ离子上述组态能级,获得了能级结构参数的最佳计算值.由这些参数值进一步预测计算了ZnⅩⅨ离子n=3Complex中3d2-3p3d组态能级跃迁的谱线波长,振子强度和跃迁概率.     

Supertransferred Hyperfine Magnetic Fields at 111Cd Impurity Sites in Cd x Fe3−x O4 and Zn x Fe3−x O4

The hyperfine magnetic field at ¹¹¹Cd impurities substituting iron in the mixed spinels Cd _x Fe_3−x O₄ and Zn _x Fe_3−x O₄ has been determined by means of the Perturbed Angular Correlation technique. Compounds with different concentrations x were investigated as a function of temperature. The possibility of determining the lattice location of probes at octahedral or tetrahedral sites through the magnitude of the electric field gradient is analyzed. The measured hyperfine magnetic field at impurities in tetrahedral sites is discussed in terms of the populations of magnetic ions in the nearest neighbor sites. This revised version was published online in September 2006 with corrections to the Cover Date.     

High-Pressure Synthesis of SeCu 1− x Zn x O 3 Perovskites

The SeCu 1 m x Zn x O 3 solid solution, with a distorted perovskite-type structure, has been synthesized under high pressures and temperatures. X-ray diffraction analysis indicates that the zinc ions occupy the copper sites, a solid solution being formed. It seems that high-pressure stabilises a small cation such as Se 4+ in the A site of the perovskite structure ABO 3 although the material is better described as formed by selenite anions \rm{SeO}_{3}^{-} and Cu 2+ /Zn 2+ cations.     

Heat capacity of multiferroics Bi1–x Pr x FeO3

Physics of the Solid State - The heat capacity of multiferroics Bi1–x Pr x FeO3 (0 ≤ x ≤ 0.20) has been studied in the temperature range 130–800 K. An insignificant...