用问题设计撬动教学方式转变——由“问题串导航”到“核心问题驱动”

问题是教学的心脏,一个好问题能够激发学生的好奇心和求知欲,一旦学生有了探究问题的内驱力,学习也就自然发生.因此,课堂教学中的问题设计就显得尤为重要.如何设计教学问题,驱动学生更加主动地进行探究学习呢?本文中结合当下数学课堂教学中所暴露的问题,着重分析如何优化问题设计,以此撬动教学方式的转变.     

磁阻传感器测量地磁场实验教学体会

简要介绍了磁阻传感器的结构和工作原理,解释了标定磁场在地磁场测量中的作用。在此基础上,进一步分析了在不同磁场下磁阻传感器管脚如何调整方向以及在地磁场测量中如何找到地磁子午面等问题,通过具体的操作使学生对磁阻传感器测量地磁场实验的理解能够更加深入。     

Triaxial shape in 129Ce

The high spin states of ¹²⁹Ce have been populated via heavy-ion fusion evaporation reaction ⁹⁶Mo (³⁷Cl, 1p3n) ¹²⁹Ce. The comparison between the signature- and B(M1)-staggering defined by Hagemann and Hamamoto have been showed in the negative-parity band of ¹²⁹Ce. The lifetimes and quadrupole moments Q_t of the high spin states of ¹²⁹Ce have been extracted from the line shape analyses using Doppler shift attenuation method (DSAM). The deformation parameters extracted through the solution of equations for quadrupole transition moments Q_t and collective moments of inertia J_RR.     

重离子融合反应入射道效应的动力学研究

运用微观输运模型-改进的量子分子动力学模型(ImQMD), 研究了弹靶质量对称体系⁷⁴Ge+⁷⁴Ge与弹靶质量不对称体系⁴⁸Ti+¹⁰⁰Mo的重离子融合反应入射道效应及其动力学机制, 并分析了复合体系的均方根半径〈r²〉^1/2和形变参量β随时间的演化过程, 结果表明质量对称的反应体系比不对称体系更容易产生形变较大的Gd, 则说明重离子融合反应中的动力学效应对大形变核的产额有很大的影响.     

Features of the total disintegration events of heavyemulsion targets caused by 4.5A GeV/c16O

Total disintegration events produced by 4.5\,A GeV/c $^{16}$O--AgBr interactions are analysed to investigate the characteristics of secondary charged particles produced in such collisions. The multiplicity distributions of grey, black, and relativistic charged particles can be well represented by Gaussian distribution. The average multiplicity of grey particles is found to increase with the mass of projectile increasing, while that of black particles is found to decrease with the mass of projectile increasing. This result is in good agreement with the prediction of fireball model. Finally, the linear dependence between grey and black particles is observed, but there is no distinct dependence between the production of relativistic charged particles and the target excitation.     

用于CO2分离的混合基质膜中填充剂的研究进展

高效、绿色和低能耗的CO_2捕集技术是解决能源气体净化和温室气体减排问题的关键。膜分离技术以其高效、节能、低碳等特点在CO_2捕集领域具有潜在的发展前景。目前,CO_2分离膜的研究主要集中在混合基质膜内的填充剂,通过调控填充剂解决膜内渗透性和选择性间的"博弈"效应。近年来,研究者们发现填充剂通常是影响混合基质膜分离性能的关键因素,采用不同的填充剂可改善混合基质膜的气体分离性能。基于此,本文对目前已经开发出的填充剂进行了归纳总结,以便为设计开发新型混合基质膜用于CO_2分离提供参考。     

Lifetimes of High Spin States in an Odd-Proton Nucleus 129Cs

Lifetimes of high spin states in 129Cs axe measured using the Doppler shift attenuation method. The high spin states of 129 Cs axe populated following the fusion evaporation reaction 124 Sn（UB, 6n）129 Cs at a beam energy of 65 MeV. The reduced transition probabilities B（E2） and the transition quadrupole moments Qt in the negativeand positive-paxity bands are deduced. The experimental results indicate that the Qt values of the negative parity band are smaller than those of the positive parity bands, probably due to different γ-deformation driving effects of different proton orbitals. The Qt values exhibit a considerable increase near the band crossing region in these bands. This behavior demonstrates that nuclear shape changing results from the neutron or proton alignments. The signature splitting of the πh11/2 and πg7/2 bands shows the opposite changing trend after backbending due to the h11~2 neutron and h11/2 proton alignments, respectively.     

Structure change of 156Yb at high-spin states

High-spin states of ¹⁵⁶Yb have been studied via the ¹⁴⁴Sm(¹⁶O,4n)¹⁵⁶Yb fusion-evaporation reaction at beam energy 102~MeV. The positive-parity yrast band and negative-parity cascade have been extended up to higher-spin states, respectively. The characteristics of the negative-parity sequence above the 25^－ state may related to the excitation from the nucleon in the Z=64, N=82 core. The E-GOS curve for the positive-parity yrast sequence in ¹⁵⁶Yb indicate that this nucleus may undergo an evolution from quasivibrational to quasirotational structure with increasing angular momentum. The Cranked Woods-Saxon-Strutinsky calculations by means of Total-Routhian-Surface (TRS) methods has been made to understand this structure change.     

Shape evolution and test of the critical-point symmetry X(5) in 176Os

The lifetimes of excited states in the yrast band of ¹⁷⁶Os have been measured up to I=20h level using the Doppler shift attenuation method. The high-spin states of ¹⁷⁶Os were populated via fusion evaporation reaction ¹⁵²Sm(²⁸Si, 4n)¹⁷⁶Os at a beam energy of 140 MeV. The results support an X(5) structure for ¹⁷⁶Os at low spin. This structure disappears at high spin and shows a symmetry rotor character. The shape change of ¹⁷⁶Os is similar to that of ¹⁷⁸Os.     

High-spin states and signature inversion studies in 110Ag

The high-spin states of ¹¹⁰Ag were populated via fusion evaporation reaction ¹¹⁰Pd(⁷Li, 2p2n)¹¹⁰Ag and a new level scheme has been presented. The systematics of signature splitting and signature inversion of the πg_9/2⊙νh_11/2 configuration band in Ag isotopes are studied. The spin of inversion point decreases with increasing neutron number and this feature is explained as due to the competition between the p-n residual interaction and the Coriolis force.