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91.
In this report we investigate η-meson productions on the proton via electromagnetic and hadron probes in a chiral quark model approach. The observables, such as, differential cross section and beam asym-metry for the two productions are calculated and compared with the experiment. The five known resonances S_(11)(1535), S_(11)(1650), P_(13)(1720), D_(13)(1520), and F_(15)(1680) are found to be dominant in the reaction mech-anisms in both channels. Significant contribution from a new S_(11) resonances are deduced. For the so-called "missing resonances", no evidence is found within the investigated reactions. The partial wave amplitudes for π~-p→ηn are also presented.  相似文献   
92.
Using the model with one particle and one hole coupled with a triaxial rotor, the πg(-1)(9/2)(⊕)vh11/2 doublet bands in the A ~ 100 mass region are studied, and compared with the πh11/2(⊕)vh(-1)(11/2) doublet bands.It is found that the calculated results for the configuration of πg(-1)(9/2)(⊕)vh11/2 are very similar the results for a pure h11/2 proton particle and a neutron quasiparticle with λn =ε5. After including the pair correlation, the model describes the candidate chiral doublet bands in 106Rh successfully, which supports the interpretation of chirality geometry.  相似文献   
93.
High spin states in A ~ 110 neutron-rich 106Mo, 110Ru and 112Ru nuclei have been reinvestigated by measuring the prompt γ-rays from the spontaneous fission of 252Cf. Two similar sets of bands are observed to high spins in each of three nuclei. Through analyzing of characters of the band structures, the chiral doublet bands are suggested in 106Mo, 110Ru and 112Ru.  相似文献   
94.
俞杭  徐锡方  牛谦  张力发 《物理学报》2018,67(7):76302-076302
在经典的物理学理论中,声子广泛地被认为是线极化的、不具有角动量的.最近的理论研究发现,在具有自旋声子相互作用的磁性体系(时间反演对称性破缺)中,声子可以携带非零的角动量,在零温时声子除了具有零点能以外还带有零点角动量;非零的声子角动量将会修正通过爱因斯坦-德哈斯效应测量的回磁比.在非磁性材料中,总的声子角动量为零,但是在空间反演对称性破缺的六角晶格体系中,其倒格子空间的高对称点上声子具有角动量,并具有确定的手性;三重旋转对称操作给予声子量子化的赝角动量,赝角动量的守恒将决定电子谷间散射的选择定则;此外还理论预测了谷声子霍尔效应.  相似文献   
95.
The circular dichroism of titanium‐doped silver chiral nanorod arrays grown using the glancing angle deposition (GLAD) method is investigated in the visible and near infrared ranges using transmission ellipsometry and spectroscopy. These films are found to have significant circular polarization effects across broad ranges of the visible to NIR spectrum, including large values for optical rotation. The characteristics of these circular polarization effects are strongly influenced by the morphology of the deposited arrays. Thus, the morphological control of the optical activity in these nanostructures demonstrates significant optimization capability of the GLAD technique for fabricating chiral plasmonic materials.

  相似文献   

96.
1.IntroductionMutuallypumPedphaseconjugatemirrorsarenonlineardevicesthatsimultaneouslyproducephaseconjugatereplicasoftwomutuallyincoherentbeams.TheyattractedgreatattentionbecauseoftheirnumerousPotentialapplicationsinadaptiveoptics,opticalinfor-mationprocessing,laserlocking,optica1communication,opticalneuralnetwork,andsoon[l~s1.Variousschemesleadingtomutualphaseconjugationhavebeendemonstrated,includingdoub1ephaseconjugatemirror(DPCM)['J,mutua1lyincoherentbeamcou-pler[:J,birdwingphaseconjugat…  相似文献   
97.
共轭梯度法求解多宗量瞬态热传导反问题   总被引:5,自引:3,他引:5  
提出瞬态热传导反问题中热物性参数和边界条件多宗量反演的一般数值求解模式,导出了敏度计算公式,并用共轭梯度法求解,探讨了测点数目、测量误差和变量初值对反演结果的影响,并进行了数值验证.  相似文献   
98.
A quark meson coupling model based on SU(3)L×SU(3)R symmetry and scale invariance is proposed. The quarks and mesons get masses through symmetry broken. We apply this SU(3) chiral constituent quark model to investigating the nuclear matter at finite temperature and density. The effective baryon masses, compression modulus and hyperon potentials are all reasonable. The critical temperature of liquid-gas phase transition is also calculated in this model.  相似文献   
99.
寇谡鹏 《中国物理》2001,10(5):398-402
Using Parisi and Sourlas dimensional reduction, four-dimensional quantum chromodynamics is reduced to a two-dimensional principal chiral model by suitable superspace embedding. The frame Ta cannot be regarded as a fixed one and the frame connection field \varωμ(x) becomes a dynamical gauge field in two dimensions, giving rise to a confining potential. As a result of the original SU(3) Yang-Mills field obtains another SU(3) local symmetry and turns into SU(3)×SU(3) local symmetry-one group element as exp (iδ\varphiaTa) with fixed frame Ta, the other gauging the frame Ta.  相似文献   
100.
ABSTRACT

(S)-(+)-Dihydro-3-hydroxy-4,4-dimethyl-2(3H)-furanone, (R)-(-)-dihydro-3-hydroxy-4,4-dimethyl-2(3H)-furanone, (S)-(-)-dihydro-4-hydroxy-2(3H)-furanone, and (S)-(-)-5-hydroxymethyl-2(5H)-furanone in the presence of pure enantiomers of 2,2,2-trifluoro-1-(9-anthryl)ethanol were studied by 1H NMR in deuterated chloroform solutions. Experimental Job's plots suggest that the resulting solvates are formed with one molecule of solute and one of the chiral solvating agent. From the magnitude of the association constant determined for (S)-(+)-dihydro-3-hydroxy-4,4-dimethyl-2(3H)-furanone in the presence of (R)-(-)-2,2,2-trifluoro-1-(9-anthryl)ethanol (1.26 ± 0.09 M?1), it is inferred that the solvate is weak and cannot be isolated at 298 K. The correlation between the magnitude of induced chemical shifts, NOESY maps, and the known configuration of solutes and chiral solvating agents suggests that intermolecular hydroxyl-hydroxyl interaction is the primary interaction. Accordingly, the secondary interaction might occur between benzylic-hydrogen of the chiral solvating agent and the carbonyl- or furan ring-oxygen atoms of the solute.  相似文献   
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