Structure and 2p decay mechanism of^(18)Mg

The recently discovered,extremely proton-rich nuclide 18 Mg exhibits ground-state decay via two sequential two-proton(2p)emissions through the intermediate nucleus,16Ne.This study investigates the structure and the initial 2p decay mechanism of^(18)Mgby examining the density and correlations of the valence protons using a three-body Gamow coupled-channel method.The results show that the ground state of^(18)Mgis significantly influenced by the continuum,resulting in a significant s-wave component.However,based on the current framework,this does not lead to a significant deviation in mirror symmetry in either the structure or spectroscopy of the 18Mg-18C pair.Additionally,the time evolution analysis of the^(18)Mgground state suggests a simultaneous 2p emission during the first step of decay.The observed nucleon-nucleon correlations align with those of the light-mass 2p emitters,indicating a consistent decay behavior within this nuclear region.

新征途 新愿景 且看采埃孚天合如何发挥“POWER OF^2”

2015年春天,采埃孚(ZF)成功收购美国天合汽车集团(TRW)后,跻身于全球三大汽车供应商之一。采埃孚天合通过重组业务,使其产品组合覆盖范围有了显著的扩展,不单单是产品组合的数字累加,而是通过跨行业的产品和技术形成互补,形成"power of^2",由汽车零配件供应商提升为与博世集团比肩的系统供应商。

Enhancing ^(*)CO coverage on Sm-Cu_(2)O via 4f-3d orbital hybridization for highly efficient electrochemical CO_(2) reduction to C_(2)H_(4)

The electrocatalytic conversion of CO_(2) into valuable chemical feedstocks using renewable electricity offers a compelling strategy for closing the carbon loop.While copper-based materials are effective in catalyzing CO_(2) to C_(2+)products,the instability of Cu^(+)species,which tend to reduce to Cu~0 at cathodic potentials during CO_(2) reduction,poses a significant challenge.Here,we report the development of SmCu_(2)O and investigate the influence of f-d orbital hybridization on the CO_(2) reduction reaction (CO_(2)RR).Supported by density functional theory (DFT) calculations,our experimental results demonstrate that hybridization between Sm^(3+)4f and Cu^(+)3d orbitals not only improves the adsorption of *CO intermediates and increases CO coverage to stabilize Cu^(+) but also facilitates CO_(2) activation and lowers the energy barriers for CAC coupling.Notably,Sm-Cu_(2)O achieves a Faradaic efficiency for C_(2)H_(4) that is 38%higher than that of undoped Cu_(2)O.Additionally,it sustains its catalytic activity over an extended operational period exceeding 7 h,compared to merely 2 h for the undoped sample.This research highlights the potential of fd orbital hybridization in enhancing the efficacy of copper-based catalysts for CO_(2)RR,pointing towards a promising direction for the development of durable,high-performance electrocatalysts for sustainable chemical synthesis.

煤气柜光纤测量的精度补偿技术

由于大型一氧化碳气柜在数十米的工作行程中，柜体始终沿导轨交替地左右旋转２０°，光纤柜位计测得的钢绳长度并不是气柜的真实高度。将柜位计的计量钢绳移至柜顶计算好的点上，可以较好地弥补这一误差。但通过二次仪表的中央处理器用数学公式来修正所测数据，才是充分发挥光纤传感器高精度优越性的根本方法。

Metabolic cost of flight and aerobic efficiency in the rose chafer,Protaetia cuprea(Cetoniinae)

Rose chafer beetles(Protetia cuprea)are pollinators as well as agricultural pests,flying between flowers and trees while foraging for pollen and fruits.Calculating the energy they expend on flying during foraging activity faces the challenge of measuring the metabolic rate(MR)of free-flying insects in an open space.We overcame this challenge by using the bolus injection of ^(13)C Na-bicarbonate technique to measure their metabolic energy expenditure while flying in a large flight arena.Concurrently,we tracked the insects with high-speed cameras to extract their flight trajectory,from which we calculated the mechanical power invested in flying for each flight bout.We found that the chemical(metabolic)energy input converted to mechanical flight energy output at a mean efficiency of 10.4%±5.2%,with a trend of increased efficiency in larger conspecifics(efficiency scaled with body mass to the power of 1.4).The transition in the summer from a diet of pollen to that of fruits may affect the energy budget available for foraging.Starved P.cuprea,feeding on apples ad libitum,increased their body mass by an average of 6%in 2 h.According to our calculations,such a meal can power a 630-m flight(assuming a carbohydrate assimilation efficiency of 90%).Pollen,with a low water and carbohydrate content but rich in proteins and lipids,has a higher caloric content and should assimilate differently when converting food to flight fuel.The high cost of aerial locomotion is inherent to the foraging behavior of rose chafers,explaining their short flight bouts followed by prolonged feeding activity.

Direct search for primordial ^(244)Pu in Bayan Obo bastnaesite

The abundances of heavy elements produced in r-process nucleosynthesis in the early solar system need experimental verification.^(244)Pu could be the heaviest primordial nuclide produced before the formation of the Earth still being detectable today.As recent attempts failed to confirm the discovery of ^(244)Pu signals at a concentration of 1.0×10^(-18)g/g in bastnaesite reported by Hoffman et al.in this study,the total primordial ^(244)Pu in 450 g bastnaesite sample from Bayan Obo ore (China) was measured using ultrasensitive compact accelerator mass spectrometry (AMS).As no ^(244)Pu signal was detected,an upper limit for the ^(244)Pu in our bastnaesite sample was estimated to be 2.1×10^(-20)g/g at 99%confidence level.

Measurements of ^(nat) Cd(γ,x)reaction cross sections and isomer ratio of ^(1,5m.g)Cd with the bremsstrahlung end-point energies of 50 and 60 MeV

The flux-weighted average cross sections ^(nat) Cd(γ,xn)^(115g,m,111m,109,107,105,104)Cd and ^(nat) Cd(γ,x)^113g,112,111g,110m)Ag reactions were measured at the bremsstrahlung end-point energies of 50 and 60 MeV.The activa tion and off-line y-ray spectrometric technique was carried out using the 100 MeV electron linear accelerator at the Pohang Accelerator Laboratory,Korea.The ^(nat)lCd(γ,xn) reaction cross sections as a function of photon energy were theoretically calculated using the TALYS-1.95 and the EMPIRE-3.2 Malta codes.Then,the flux-weighted average cross sections were obtained from the theoretical values of mono-energetic photons.These values were compared with the flux-weighted values from the present study and were found to be in general agreement.The measured experimental reaction cross-sections and integral yields were described for cadmium and silver isotopes in the ^(nat)Cd(γ,xn)^(115g,m,111m,109,107,105,104) and ^(nat)Cd(γ,x)^(113g,112.111g,110m)Ag reactions.The isomeric yield ratio(IR) of ^(115g.m)Cd in the ^(nat)Cd(γ,xn) reaction was determined for the two bremsstrahlung end-point energies.The measured isomeric yield ratios of ^(115g,m)Cd in the ^(nat)Cd(γ,xn) reaction were also compared with the theoretical values of the nuclear model codes and previously published literature data of the ^(116)Cd(γ,x) and ^116(γ,2n) reactions.It was found that the IR value increases with increasing projectile energy,which demonstrates the characteristic of excitation energy.However,the higher IR value of ^(115g.m)Cd in the ^(116)Cd(n,2n)reaction compared to that in the ^(116)Cd(γ,x)reaction indicates the role of compound nuclear spin alongside excitation energy.