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1.
推出了转动元球坐标参数与欧拉角参数之间的相互变换公式;引入了用球坐标参数表示的D 函数Djm′m(θ,φ,ω) 并讨论了它的一些重要性质,由此还得到了djm′m( ω) 的傅里叶级数表示,表明函数矩阵dj( ω) 完全由它在ω= π2 时的取值矩阵dj π2 决定,而后者的计算又可归结为求一个简单的整数矩阵Cj.  相似文献   

2.
采用密度泛函理论(DFT)中的B3LYP方法得到了(AlB2)m团簇的平衡几何结构. 计算并分析了基态掺杂团簇的平均结合能、电离势、能隙和前线分子轨道. 结果表明:掺杂团簇(AlB2)m (m=1~6)整体上具有较高化学活性,(AlB2)5团簇具有金属特征. Al原子总是向团簇外围扩散并且以配位数较少的方式与主团簇结合,团簇表现出以AlB2分子为基元生长的迹象. B-Al键长大于B-B键长. 电荷总是从Al原子转移到B原子. (AlB2)m团簇中B原子的2p轨道在成键中起主要作用,并使(AlB2)m团簇趋于形成离域π键.  相似文献   

3.
本文利用置换群CG系数计算了五个粒子以内的所有SU(mn) SU(m)×SU(n)单粒子母分系数.  相似文献   

4.
进一步研究了辅助方程法,给出了几种常用辅助方程的新解、B(a|¨)cklund变换和解的非线性叠加公式.在此基础上,根据m和n的不同情况,利用变换和直接积分相结合的方法,获得了K(m,n)方程与B(m,n)方程的无穷序列新精确解.这里包括无穷序列光滑孤立子解、无穷序列尖峰孤立子解和无穷序列紧孤立子解.  相似文献   

5.
利用γ闪烁谱仪和γ—γ符合谱仪,我们对Ag~(110m)衰变的γ射线进行了研究;提出了一个修正的衰变纲图,认为Cd~(110)有656kev,1473kev,1540kev,2160kev,2219kev,2476kev和2924kev七个激发能级,包含有能量为448,620,656,679,705,741,764,817,884,936,1384,1473,1504和1560kev的14条γ射线。用符合方法,我们除了证实一般公认为有级联关系的γ射线之间有符合之外,还确定了1560kevγ射线在衰变图中的位置,证实了764kevγ射线应该放在1504kevγ射线的前面,并且指出,817kevγ射线是属于1473kev能级到656kev能级间的跃迁的。此外,还观察到1820kev和2268kev两个峰;经过用吸收方法分析,指出它们是由于低能量的γ射线“堆积”起来的迭加峰。  相似文献   

6.
本文利用置换群CG系数计算了五个粒子以内的所有SU(mn)SU(m)×SU(n)单粒子母分系数。  相似文献   

7.
8.
ABSTRACT

The concentration of carbon dioxide (CO2) has a significant influence on the morphology of thermal decomposition products of magnesite. So, structures, stabilities and adsorption mechanisms of (MgO)m (m?=?1–6) clusters by one or two CO2 molecules were calculated by the GGA-PW91 method. The results show that the stability of the considered clusters is (MgO)m(CO2)2 clusters > (MgO)m(CO2) clusters > (MgO)m clusters by the average binding energy. Certain low-lying isomers of (MgO)m(CO2) and (MgO)m(CO2)2 clusters which have an isolated O atom are deviating from the cluster center which possess higher kinetic activity. (MgO)m clusters prefer to adsorb a CO2 molecule, while (MgO)3(CO2) clusters prefer to adsorb a CO2 molecule rather than the neighbors. Magnesite is difficult to transit to (MgCO3)2 clusters at room temperature. However, magnesite will spontaneously transit to (MgO)2 clusters and further transit to MgO crystal which need to adsorb more energy at 700?K.  相似文献   

9.
提出了一个基于高维2m+1粒子纠缠态的任意m粒子态量子可控离物传态方案,发送方Alice对需传送的未知态量子系统和手中的纠缠粒子执行m个广义Bell基测量,控制方执行广义X基测量,依据预先共享量子纠缠态非定域相关性,接收方对手中的粒子执行相应的幺正操作就可以重建原来未知量子态.与其他方案相比,方案减少了任意高维多粒子态可控离物传送所需传送粒子数.我们进一步讨论了基于纯纠缠信道的概率量子可控离物传态方案,通过与发送方和控制方合作,接收方只需对手中的纠缠粒子和引入的附加粒子执行联合幺正演化和投影测量,就可以在他的粒子上概率的重建原来的未知量子态,最后,方案计算讨论了基于纯纠缠态量子可控离物传态成功概率与信道纠缠度之间的关系.  相似文献   

10.
本文测量了满壳缺一个中子的~(87)Sr(n,n′)~(87m)Sr,E_n<2MeV的非弹散射截面值,把原有的激发曲线延伸到了低能部分,构成了一条完整的激发曲线。  相似文献   

11.
The interaction of metals with hydrogen is of importance in several areas of technology. Lithium-hydrogen complexes are particularly amenable to theoretical study. Although no stable compound of the Li atom and H2 has been found, a weak dative interaction forms between the σ bond of H2 and the positively charged Li atom for Li+, Li-H+, and Li-H. At least four H2 molecules can be complexed by Li+, and three by Li-H+ and Li-H. The presence of the Li ion does not substantially weaken the H2 bond, nor is the energy of dissociation affected; however, the Li ion does form stable complexes with the dissociated H atoms.  相似文献   

12.
K(m,n)方程的对称性约化   总被引:4,自引:0,他引:4       下载免费PDF全文
  相似文献   

13.
Two hundred ninety experimental absolute intensities of nu(1) and nu(3) transitions of ozone have been measured, with good accuracy (<2%). They are used to derive the transition-moment parameters for these bands. The agreement between our observed and calculated line intensities is satisfactory. This work shows that the intensities of these two bands are on average 4% smaller than those used in the literature. In addition, 20 intensities of the nu(2) + nu(3) - nu(2) band confirm this value. Also, 42 line intensities of the 2nu(1)-nu(3) band are reported. Copyright 2001 Academic Press.  相似文献   

14.
K(m,n)方程的对称性约化   总被引:3,自引:0,他引:3       下载免费PDF全文
王烈衍 《物理学报》2000,49(2):181-185
利用对称性约化的直接法,给出了具有非线性色散情况下的K(m,n)模型的所有对称性约化.从第一种约化方程的Painlev啨性质分析可知,K(m,n)模型仅当m=n+1和m=n+2时是可积的.特殊情况下(行波约化),这种约化的解可用一个积分表示.给出了K(m,1)和K(m,m)的一般孤波解的明显表达式. 关键词:  相似文献   

15.
The 7000-8500 cm(-1) spectral region of (12)C(16)O(2) has been investigated using the high-resolution FT spectrometer of LPPM in Orsay. The two strongest bands in this region are the 10031 <-- 00001 and 10032 <-- 00001 bands centered at 8294 and 8192 cm(-1). Line intensities in these two bands and in the 40013 <-- 00001 and 40014 <-- 00001 bands have been measured. Using the method of effective operators, these line intensities have been included in a new fit of effective dipole-moment parameters to all available experimental data in the same spectral region of (12)C(16)O(2). The corresponding calculated line intensities of the 10031 <-- 00001 and 10032 <-- 00001 bands are compared with the experimental ones. Copyright 2000 Academic Press.  相似文献   

16.
17.
The Nd:YAG (1.444 m) and Cr:Tm:Ho:YAG (2.1 m) free-running laser systems of the output energy of 300 mJ per pulse and repetition rate 1 Hz have been developed and used for bile duct stones fragmentation study in vitro. A total of 67 human bile duct stones of known sizes, collected from surgical sources were used in the experiments. Insensitivity of the stones fragmentation to the type of the laser used, and insensitivity of the fragmentation efficiency to the type of stone, was observed. No pathological changes of the tissue were observed for non-human soft tissue laser irradiation (in vitro) by 1, 2, and 5 pulses of the Cr:Th:Ho:YAG radiation of the fluency of 1.6 J/cm2. The lasers are found to be good candidates for laser lithotripsy.  相似文献   

18.
Differential scanning calorimetry (DSC) thermograms, X-ray diffraction (XRD) analysis, electrical conductivity (σ), and 7Li NMR spectroscopy characterization of n-C m H(2m?+?1)COOM solids (M = Li, Na, K; m?=?13, 15, 17, 19, 21) and mixed crystals n-C21H43COOLi x K(1???x) (0.25?≤?x?≤?0.75) was performed as a function of temperature. DSC thermograms of n-C m H(2m?+?1)COOM revealed several solid-solid phase transitions with large entropy changes. Electrical conductivity studies established that n-C m H(2m?+?1)COOLi crystals are poor electrical conductors. In contrast, n-C m H(2m?+?1)COOK salts were found to have σ values of 10???7–10???8 S·cm???1. Since the crystal structures and phase-transition temperatures of both n-C m H(2m?+?1)COOLi and n-C m H(2m?+?1)COOK crystals were similar, they were able to form mixed crystals with the structure n-C x H(2m?+?1)COOLi x K(1???x). DSC thermograms of the mixed crystals showed a small entropy change at the melting point (ΔS mp?<?13 J K???1 mol???1), in addition, large ΔS values at the solid-solid phase transition temperature. The σ values obtained for mixed crystals were roughly one order of magnitude greater than those determined for n-C21H43COOK crystals. 7Li NMR spectra of the mixed crystals recorded at various temperatures suggested that the self-diffusion of Li?+? ions was excited in the highest-temperature solid phase. Based on these results, we have classified these mixed crystals as rotator crystals.  相似文献   

19.
Both particle physics and the 1890s Seeliger–Neumann modification of Newtonian gravity suggest considering a “mass term” for gravity, yielding a finite range due to an exponentially decaying Yukawa potential. Unlike Nordström’s “massless” theory, massive scalar gravities are strictly Special Relativistic, being invariant under the Poincaré group but not the conformal group. Geometry is a poor guide to understanding massive scalar gravities: matter sees a conformally flat metric, but gravity also sees the rest of the flat metric, barely, in the mass term. Infinitely many theories exhibit this bimetric ‘geometry,’ all with the total stress–energy’s trace as source. All are new except the Freund–Nambu theory. The smooth massless limit indicates underdetermination of theories by data between massless and massive scalar gravities. The ease of accommodating electrons, protons and other fermions using density-weighted Ogievetsky–Polubarinov spinors in scalar gravity is noted.  相似文献   

20.
Ablation of the surface of a polyimide (Kapton) film by single pulses of 248 nm or 308 nm radiation (20 ns) or 9.17 m laser radiation (170 ns) was studied by photographing the emergence of the blast wave and the plume by a pulse (<1 ns; 596 nm) of visible laser light. The dynamics of the blast wave was similar in the ultraviolet and in the infrared but the composition of the plume was obviously different. A mass of opaque solid material was ejected for as long as 2.6 s following the IR pulse in contrast to the minute amount of solids that are seen in the ablation by UV laser pulses of ns duration. UV laser pulses of 50–400 s duration interact with polyimide surfaces in a manner that is similar to IR laser pulses of ns duration or longer. Chemical analysis of the ablation products that are obtained under various conditions of ablation when compared to the known modes of thermal degradation of polyimide show that the reaction is a thermal process when IR laser pulses or UV laser pulses of long (>10 s) duration are employed. Ablation by ns UV laser pulses differs fundamentally in the chemistry of the products from all of the cases mentioned above.  相似文献   

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