Preparation and properties of a left-handed metamaterial composite

A left-handed metamaterial (a YIG/Ag composite with adjustable negative permittivity and permeability) was prepared by an in situ synthesis process, and its characterisation, microstructure, electrical conductivity, dielectric loss and magnetic properties studied. A negative permittivity behaviour with a Fano-like resonance is ascribed to plasma oscillation of delocalised electrons from silver conducting networks. As the silver content increases, the turbine loss increases, which greatly enhances the electromagnetic wave consumption capacity inside the material and leads to a stronger electromagnetic absorption and shielding performance. The dielectric loss near the percolation threshold is due to the combined effects of polarisation and conduction. The capacitive character is responsible for positive permittivity, and the inductive character leads to negative permittivity. LC resonance results in the Fano-like resonance, leading to the permittivity changing from negative to positive. Gyromagnetic spin rotation, domain wall motion and percolation characteristic of YIG/Ag composites cause frequency dispersion of the permeability. The YIG/Ag composite with double negative characteristics provides prospects for electromagnetic shielding application.     

High-pressure phase transition and lattice dynamics of rock-salt and FeSi-type phases of MgS

A phase transition of MgS under high pressure is investigated using a first-principles method. It is found from energy-volume calculations that the rock-salt (B1) phase of MgS transforms into a FeSi-type (B28) phase at 143?GPa. The calculated ground-state parameters in the B1 phase are in excellent agreement with available experimental and theoretical data. Ab initio phonon calculations are also performed to investigate the structural behaviour of MgS under high pressure. An unstable transverse acoustic mode and a phase transition from B1 to B28 phase at ~143.7?GPa driven by this soft mode are predicted. The B28 structure of MgS is stable up to 350?GPa according to lattice dynamics calculations.     

儿童社会观点采择的发展及其与同伴互动关系的研究

采用经过标准化处理的观点采择故事对幼儿园大班和小学二、四、六年级儿童的社会观点采择能力进行测量,利用录像观察技术和同伴评定法分别测定幼儿园大班和小学儿童的同伴社会互动经验,考察儿童社会观点采择的发展及其与同伴互动经验之间的关系。研究发现：（１）幼儿园大班儿童在准确采择他人观点方面还存在较大困难,６－１０岁为儿童社会观点采择能力快速发展的时期,１０岁左右的小学儿童能够根据有关事件信息准确推断他人的观     

婚姻关系、亲子关系对3～6岁幼儿心理行为问题的影响

采用CBCL量表、自编的婚姻关系和亲子关系问卷调查了6所城市幼儿园的457名3～6岁幼儿,结果发现：(1)本研究中3～6岁幼儿心理行为问题的检出率为15．10％;(2)3-6岁幼儿的心理行为问题主要表现为交往不良、攻击性等外部行为问题;(3)没有心理行为问题的幼儿家庭其婚姻关系在性格相容、问题解决和性生活方面显著优于有心理行为问题的幼儿家庭,但在经济条件方面则相反;(4)婚姻关系和亲子关系则呈显著的正相关,并共同影响幼儿的心理行为问题。     

Arrow Logic and Infinite Counting

We consider arrow logics (i.e., propositional multi-modal logics having three -- a dyadic, a monadic, and a constant -- modal operators) augmented with various kinds of infinite counting modalities, such as 'much more', 'of good quantity', 'many times'. It is shown that the addition of these modal operators to weakly associative arrow logic results in finitely axiomatizable and decidable logics, which fail to have the finite base property.     

Caregivers’ emotional competence and behavioral responsiveness as correlates of early childcare workers’ relationships with children in their care

In the current study, we examined associations among early childcare workers’ emotional competence, observed responsiveness, comfort with socioemotional teaching practices, and the quality of their relationships with children in their care. The participants were 100 early childcare workers (72 center-based Early Head Start teachers and 28 family childcare providers). Results showed that caregivers’ emotion regulation ability was positively associated with caregiver–child relational closeness. Understanding and regulation of emotion were both positively associated with childcare workers’ comfort with socioemotional teaching practices. Their observed responsiveness was positively related to relational closeness and negatively related to relational conflict. Findings are consistent with aspects of the prosocial classroom model, which asserts that educators high in emotional and social competence tend to adopt childcare practices that result in supportive relationships with children. Results provide insight into whether childcare workers’ responsiveness to young children and their perceived socioemotional teaching practices provide a pathway between emotional competence and the quality of caregiver–child relationships.     

Distance stability analysis in multidimensional scaling using the jackknife method

Stability or sensitivity analysis is an important topic in data analysis that has received little attention in the application of multidimensional scaling (MDS), for which the only available approaches are given in terms of a coordinate‐based analytical jackknife methodology. Although in MDS the prime interest is in assessing the stability of the points in the configuration, this methodology may be influenced by imprecisions resulting from the inherently necessary Procrustes method. This paper proposes an analytical distance‐based jackknife procedure to study stability and cross‐validation in MDS in terms of the jackknife distances, which is not influenced by the Procrustes method. For each object, the corresponding jackknife estimated points are considered as naturally clustered points, and stability and cross‐validation are analysed in terms of the MDS distances arising from the jackknife procedure, on the basis of a weighted cluster‐MDS algorithm. A jackknife‐relevant configuration is also proposed for cross‐validation in terms of coordinates, in a cluster‐MDS framework.     

Quality Instances and the Structure of the Concrete Particular

In this paper, I examine a puzzle that emerges from what J. P. Moreland has called the traditional realist view of quality instances. Briefly put, the puzzle is to figure out how quality instances fit into the overall structure of a concrete particular, given that the traditional realist view of quality instances prima facie seems incompatible with what might be called the traditional realist view of concrete particulars. After having discussed the traditional realist views involved and the puzzle that emerges from their juxtaposition, I propose an alternative realist view of quality instances which resolves the puzzle. In short, the puzzle is solved by treating the distinction between a concrete particular and its quality instances as a distinction of reason, and by adopting the view that the individuating element of a concrete particular must also serve as its unifying element – a view which Moreland, one of traditional realism’s most stalwart contemporary defenders, rejects.     

对我国农村卫生改革中若干关系的思考

在农村卫生改革中,要确保公有制卫生机构的"主导"地位,把握其与合作医疗制度之间的内在联系,严格区别乡镇卫生院的产权与债权,处理好乡镇卫生院所有权与经营权、乡镇卫生院与村级卫生组织、农村居民与新型合作医疗之间的关系.     

On the (numerical) ranking associated with any finite binary relation

We generalize the concept of a ‘ranking associated with a linear order’ from linear orders to arbitrary finite binary relations. Using the concept of differential of an object in a binary relation as theoretical primitive, we axiomatically introduce several measurement scales, some of which include the generalized ranking as a special case. We provide a computational formula for this generalized ranking, discuss its many elegant properties and offer some illustrating examples.