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A novel ancillary ligand(2-(1-hydroxy-naphthyl)-benzothiozolato)(HNBT) and the corresponding red emitting phosphorescent iridium(Ⅲ) complex,Ir(ppy)2(NBT) with 2-phenylphridine(ppy) as first ligand are designed and synthesized.Saturated red-emitting electrophosphorescent devices using Ir(ppy)2(NBT) as emission center are fabricated.The thermal,photophysical,and electroluminescent properties of Ir(ppy)2(NBT) are investigated in detail.It is noteworthy that the emission spectrum shape of complex Ir(ppy)2(NBT) is similar to Gauss,which has only one emission peak centralized 614 nm with a full-width at half-maximum of 65 nm.The optimized device exhibits a maximum brightness of 6 400 cd/m2 and the peak current efficiency is 4.53 cd/A.

With the exposure of serious problems in a series of enterprise groups such as Lantian Group, Yinguangxia Group, Delong and Nanhai huaguang Group, the credit risks stand out for those commercial banks, which provide loans to these enterprise groups. Enterprise groups have complicated of organizational structure and concealed internal transactions, which mean that enterprise groups are grey systems. However, commercial banks matching credit evaluation and credit management at their developing stages lack of a whole objective technology that is suitable for management regulations and credit rating system. Based on investigation and research on persons, this paper proposes specially credit evaluation index system of group enterprises, including quantitative and qualitative indexes. It processes these indexes by principal component analysis method and entropy method based on grey relational analysis model of the credit score values of enterprises. Finally, it evaluates grey relational grade of credit risk between parent corporation and its subsidiary about Group “QiaQia”. The results of this analysis are consistent with practice.

Frequency of an internal-mirror He-Ne laser is stabilized by using a micro cooling fan, instead of traditional heating method. Both the relationship between driving voltage and rotating speed and the thermal expansion of the intermal-mirror laser are discussed. The cavity length of the laser is controlled and adjusted by air cooling. The frequency stabilization is based on a theory of power balance between two longitudinal modes. The average temperature of the laser tube is less than 50 ℃ when the frequency is stabilized. A frequency fluctuation of less than 1.4 MHz in 20 h and a frequency relative standard uncertainty of U=4.710-9 in 4 months are evaluated by measuring the beat signal with a high-precision laser stabilized by iodine.

Background Metabolic syndrome (MS) is combination of medical disorders that increase people's risk for cardiovascular disease and diabetes mellitus. Little data exists on the prevalence of MS of rural original adults in Ningxia of China. Methods A cross-sectional survey method was used and the participants were interviewed by trained health workers under a structured questionnaire in rural of Ningxia in 2008. The number of research subjects was 1612. MS was defined by International Diabetes Federation IDF (2005). Results The age-adjusted prevalence of the metabolic syndrome was 11.8%, whereas ethnic-specific prevalence was 10.3% in Han ethnic group and 13.7% in Hui ethnic group. Components of MS and MS were more common in Hui ethnic group than Han ethnic group. The mean levels and prevalence of abnormal value increased with increasing age in both ethnic groups (Cochran-Artimage test for trend, Hui ethnic group P < 0.05, Han ethnic group P < 0.01). Conclusions The prevalence of MS was high in rural residents' adults in Ningxia. Clustering of MS components and MS was increased with age. The components of MS have big differences among different ethnic groups.