Co-transition absorption property of K2ZnCl4:Co2+ crystal

Single-crystal K(2)ZnCl(4) doped with Co2+ has been grown successfully by use of the Czochralski technique. The absorption spectrum of the crystal was measured. The most intense line, centered at 650 nm, was associated with the transition (4)A(2)-->(4)T(1P), and a novel and important result that corporate transition (co-transition) between (4)A(2)-->(4)T(1F) and (4)A(2)-->(4)T(2) of Co2+ in the region of 1300-2400 nm was found and discussed. The mechanism that caused the phenomenon was explained by energy-level splitting theory. In the tetrahedral approximation, using the quantum and Tanaba-Sugano theories, Racah parameter B and crystal field parameter 10Dq were calculated. The optical energy gap, deduced to be 4.82 eV, was lower than that of pure K2ZnCl4.     

Tuning Ground States of Bis(triarylamine) Dications: From a Closed‐Shell Singlet to a Diradicaloid with an Excited Triplet State

Three bis(triarylamine) dications were isolated by using weakly coordinating anions. Their electronic structures in the ground state were investigated by various experiments in conjunction with theoretical calculations. The ground‐state electronic structures of these species were tunable by substituent effects, with two of them as closed‐shell singlets and one of them as an open‐shell singlet in the solid state. The excited state of the latter is thermally accessible, indicated by EPR and SQUID measurements. The work provides a new and stable diradicaloid structure motif with an excited triplet sate.     

法向载荷和滑动速度对GCr15钢干滑动摩擦的影响

本文研究了在干滑动摩擦情况下,GCr15钢与YG8硬质合金对磨时的摩擦系数与法向载荷及滑动速度的关系。结果表明,摩擦系数是随着法向载荷和滑动速度的增加而降低。根据磨损表面发生的变化和磨损表面温度计算,作者认为法向载荷和滑动速度的增加使闪温增高,从而导致了摩擦磨损表面的局部熔化,即形成了边界润滑,故此摩擦系数降低,而且在较高的载荷和滑动速度条件下,不同显微组织材料的摩擦系数之差减小。     

面向客户群的服务方案配置规则挖掘方法

产品/服务配置规则获取的主要方式是用数据挖掘技术从设计实例数据库中提取.客户化服务方案配置规则为服务功能需求和方案特征间的关联规则.考虑到常用关联规则挖掘算法Apriori具有运算复杂的缺点,提出基于PIETM(Principle of Inclusion—Exclusion and Transaction Mapping)算法的配置规则挖掘方法,考虑置信度和有趣度指标,提取强关联规则.针对配置实例数据库数据量较大时,配置规则挖掘的效率会降低且会产生大量冗余规则的问题,采用二元语义模型表达定性的服务功能需求,将同类客户群的功能需求进行合并,替换多样化的功能需求,减少规则的冗余.最后以一工程机械制造企业服务方案配置规则挖掘为例,验证了所提方法的有效性.     

Vertex functions for d-wave mesons in the light-front approach

While the light-front quark model (LFQM) is employed to calculate hadronic transition matrix elements, the vertex functions must be pre-determined. In this work we derive the vertex functions for all d-wave states in this model. Especially, since both ³ D ₁ and ³ S ₁ are 1⁻⁻ mesons, the Lorentz structures of their vertex functions are the same. Thus when one needs to study the processes where ³ D ₁ is involved, all the corresponding formulas for ³ S ₁ states can be directly applied; only the coefficient of the vertex function should be replaced by that for ³ D ₁. The results would be useful for studying the newly observed resonances, which are supposed to be d-wave mesons, and furthermore possible 2S–1D mixing in ψ′ with the LFQM.     

Grain size reduction and recording performance improvement by using NiW as a partial interlayer in CoCrPt/SiO2 recording medium

We report the effect of NiW, as an interlayer to partially replace Ru, on the microstructure, magnetic properties, and recording performance of CoCrPt/SiO₂ perpendicular recording media. It was found that the full width at half maximum of the rocking curves of the Co (0002) peak changed little with NiW thickness up to 10 nm. However, further increase of NiW thickness caused a larger c-axis dispersion. The grain size of the CoCrPt/SiO₂ recording layer was reduced from 10.9±1.8 nm for the films without NiW to 7.7±1.5 nm for films with 10-nm NiW as a partial interlayer. The coercivity, H _c, nucleation field, H _n, and the reverse overwrite, Rev_OV, of the CoCrPt/SiO₂ layer did not change much (less than 15%) with increased NiW thickness. However, it did affect the switching field distribution of the CoCrPt/SiO₂ layer (more than double). The recording performance was improved by using NiW as a partial interlayer, which was mainly attributed to the reduced grain size.