Beta-delayed Proton Decay of Proton Drip-line Nucleus ^(142)Ho

Unknown beta-delayed proton precursor^(142)Ho was synthesized in the reaction^(106)Cd(^(40)Ca,p3n)and identified for the first time by using a proton-gamma coincidence measurements in combination with a helium-jet fast tape transport system^([1～3]).Its beta-delayed proton spectrum was observed.The hal-life of^(142)Ho

Decay Study of the Neutron-Rich Nucleus ^(175)Er

The decay of the neutron-rich erbium isotope 175Er is studied by using the reaction176Yb（n,2p）175Er.A partial decay scheme is proposed on the basis of X-γ and γ-γ coincidencemeasurements,taking into account eight observed gamma rays.A ground rotational band is as-signed to 175Tm.Some systematic behaviors of 1/2+[411] ground rotational bands in odd-Athulium are described.The experimental and calculated decoupling parameters of these bandsare compared.

On the Mixed Propagator Approach to ρ-ω Mixing

The mixed propagator (MP) approach to ρ-ω mixing is discussed. It is found that under the pole-approximation assumption the results of MP approach is not compatible both with the effective Lagrangian theory andwith the experiment measurement criterion. To overcome these inconsistent, we propose a new MP approach in whichthe physical states of ρ and ω are determined by the requirement of experimental measurement to meson resonance. Interms of this new MP approach, the EM pion form factor Fπ and form factors of ρo →π0γ and of ω→πo γ are derived.The results of Fπ are in good agreement with data. The form factor of ρo →π0γ exhibits a hidden charge-asymmetryenhancement effect which agrees with the prediction of the effective Lagrangian theory.

解读单元考点/牵手高频考题——Units 11-12

1.What do you have in mind?(P72)【考点】have sth.in mind【归纳】have sth.in mind:想到某事;想要做某事;have sb.in mind心中想着某人【高考链接】(1)Fred,who had expected how it would go with his daughter,had a great worry _____his mind.(06湖南) A.on B.in C.with D.at

β-delayed proton decay of the proton drip-line nucleus ^(142)Ho in the rare-earth region

New β-delayed proton precursor 142Ho was produced via heavy ion induced reaction 106Cd(40Ca, p3n), and identified for the first time by using a He-jet fast tape transport system in combination with 'p-γ' coincidence measurements. The β-delayed proton decay of 142Ho was observed and its half life was determined to be (0.4±0.1) s. By fitting the experimental relative branching ratios to final states in the proton daughter nucleus 141Tb and the energy spectrum of β-delayed protons with a statistical model calculation, the ground-state spin of 142Ho was assigned as 5, 6 or 7. Nuclear energy-potential-surface (EPS) calculations were performed using the Woods-Saxon Strutinsky method. The calculated results favored the assignments of 7- to 142Ho. AS the by-products, some γ-transitions in the proton daughter nuclei following the β-delayed proton decays of precursors 139Gd, 140Tb, 142Tb, and 143Dy were reported here for the first time.

ρ-ω mixing in J/ψ→VP decays

The study of ρ-ω mixing has mainly focused on vector meson decays with isospin I = 1, namely theρ（ω）→π＋π- process. In this paper, we present a study of ρ-ω mixing in ρ（ω）→π＋π-π0（I = 0） using a flavor parameterization model for the J/ψ→VP process. By fitting a theoretical framework to PDG data, we obtain the SU（3）-breaking effect parameters sV = 0.03±0.12, sP = 0.17±0.17 and the ρ-ω mixing polarization operatorΠρω =（0.006±0.011） GeV2. New values are found for the branching ratios when the mixing effect is incorporated：Br（J/ψ→ωπ0）=（3.64±0.37）×10-4, Br（J/ψ→ωη）=（1.48±0.17）×10-3, Br（J/ψ→ωη）=（1.55±0.56）×10-4, these are different from the corresponding PDG2012 values by 19%, 15% and 15%, respectively.

On the refracted patterns produced by liquid vortices

A theoretical analysis of the refracted shadows produced by steady and time-decaying liquid vortices under uniform illumination from above is given in this article. An expression for the induced shadow intensity is derived and found to be a function of the vortex＇s free surface profile, i.e., function of the static pressure distribution. The patterns for different focusing depth are given and compared with previous visualization results from the literature. The phenomenon is examined and illustrated as a bench mark case by using both steady and time-decaying algebraic vortex models. However, this study can be extended to check the feasibility of recovering the main flow properties by analyzing the luminous image intensity of the refracted patterns. The present analysis is valid only when the swirl velocity is order of magnitude higher than the meridional flow components and the vorticity is concentrated within the core region and of intense conditions.

Strategies for Improving the Brightness of Aggregation-Induced Emission Materials at Aggregate Level

The brightness of fluorescent agents directly determines the imaging performance as required.Among various fluorophores,small organic species are promising given its exact purity/composition and excellent processibility.However,chromophores with planar geometry may suffer from the undesirable aggregation-caused quenching(ACQ)phenomenon.Encouragingly,luminogens showing aggregation-induced emission(AIE)features are preferable as the aggregates which are the most common used state.In this review,we mainly focus on the strategies employed for boosting the brightness of AIE-active luminogens(AIEgens).From molecule to mor-phology levels,approaches that regulate electronic transition processes of the molecule or the packing extent of aggregates in order to confine molecular motion,reduceπ-πstacking,disrupt fluorophore-water interactions,etc.,are presented.In the end,the current challenges and perspectives are briefly discussed.We anticipate that this review will stimulate new insights and more efforts for the advancement of ultrabright AIEgens.

STABILITY OF THE STOCHASTIC θ-METHOD FOR SUPER-LINEAR STOCHASTIC DIFFERENTIAL EQUATIONS WITH UNBOUNDED DELAY

This paper deals with numerical stability properties of super-linear stochastic differential equations with unbounded delay. Sufficient conditions for mean square and almost sure decay stability of the above system and its stochastic θ-method approximation are investigated in this paper. The author establishes numerical stability under a monotone-type condition in unbounded delay setting. An example is presented to illustrate the result.

Search for the rare decay B^(0)→J/ψФ

A search for the rare decay B^(0)→J/ψФis performed using Pp collision data collected with the LHCb dete-ctor at centre-of-mass energies of 7,8 and 13 TeV,corresponding to an integrated luminosity of9 fb.No significant signal of the decay is observed and an upper limitof 1.1x 10^(-7)at 90%confidence level is set on the branching fraction.