Effect of the work function of gate electrode on hysteresis characteristics of organic thin-film transistors with Ta2O5/polymer as gate insulator

Organic thin-film transistors (OTFTs) using high dielectric constant material tantalum pentoxide (Ta2O5) and benzocyclobutenone (BCBO) derivatives as double-layer insulator were fabricated. Three metals with different work function, including Al (4.3 eV), Cr (4.5 eV) and Au (5.1 eV), were employed as gate electrodes to study the correlation between work function of gate metals and hysteresis characteristics of OTFTs. The devices with low work function metal Al or Cr as gate electrode exhibited high hysteresis (about 2.5 V threshold voltage shift). However, low hysteresis (about 0.7 V threshold voltage shift) OTFTs were attained based on high work function metal Au as gate electrode.

G-Quadruplex Aptamers with Peroxidase-Like DNAzyme Functions: Which Is the Best and How Does it Work?

Some G-quadruplex DNA aptamers have been found to strongly bind hemin to form DNAzymes with peroxidase-like activity. To help determine the most suitable DNAzymes and to understand how they work, five previously reported G-quadruplex aptamers were compared for their binding affinity and then the potential catalytic mechanism of their corresponding hemin-G-quadruplex DNAzymes was explored. Among these aptamers, a G-quadruplex named AGRO100 was shown to possess the highest hemin-binding affinity and the best DNAzyme function. This means that AGRO100 is the most ideal candidate for DNAzyme-based analysis. Furthermore, we found the peroxidase-like activity of DNAzyme to be primarily dependent on the concentration of H2O2 and independent of that of the peroxidase substrate (that is, 2,2-azino-bis(3-ethytbenzothiazoline-6-sulfonic acid)diammonium salt). Accordingly, a reaction mechanism for DNAzyme-catalyzed peroxidation is proposed. This study provides new insights into the G-quadruplex-based DNAzymes and will help us to further extend their applications in the analytical field.

Advanced research work on radiation cross-linking of polymers in CIAC

Recent research carried out at the Chinese Institute of Applied Chemistry has contributed significantly to the understanding of the radiation chemistry of polymers. High energy radiation has been successfully used to cross-link fluoropolymers and polyimides. Here chain flexibility has been shown to play an important role, and T-type structures were found to exist in the cross-linked fluoropolymers. A modified Charlesby-Pinner equation, based upon the importance of chain flexibility, was developed to account for the sol-radiation dose relationship in systems of this type. An XPS method has been developed to measure the cross-linking yields in aromatic polymers and fluoropolymers, based upon the dose dependence of the aromatic shake-up peaks and the F/C ratios, respectively. Methods for radiation cross-linking degrading polymers in polymer blends have also been developed, as have methods for improving the radiation resistance of polymers through radiation cross-linking.

工作社会规范观念的心理学研究与跨文化比较

Data on meaning of working (MOW) were collected from 905 respondents in Beijing area through a stratified sampling procedure of the questionnaire used in the restudy of meaning of working (which is still on going, adapted for using in China). Some parts of the factor structure obtained in this study are similar to what found by the MOW International Research Team (1987). Detailed analysis and cross-cultural comparisons were concentrated on the most similar parts societal norms about working (SNW). T-scores of the obligation norm (ON) and entitlement norm (EN) of Chinese were calculated based on the reaction frequencies of relevant items provided by the MOW International Research Team and shown as follows. The results reveal the obligation orientation characteristic of Chinese respondents. And more, 4 SNW patterns of Chinese respondents were obtained through multivariate cluster analysis and multivariate discrimination analysis and shown as follows. The influences of antecedent variables on SNW and the consequences of SNW were analyzed. Two questions were raised from these analyses: 1) The present measurements of SNW are not able to reflect the nature of the relation and dependency between ON and EN and are not free from social desirability; 2) the relationship between SNW and actual working behaviors need to be tested while the relationship between SNW and several work intentions was confirmed. A forced-choice scale of SNW was designed to overcome the shortcomes of the original scale. This scale includes 30 items. Each item is composed of a ON statement and a EN statement with similar values of social desirability. A repertory grids test was used to exam the constructure validity and to analyze the differences of cognitive structures of the 4 SNW patterns. The results indicated that the new scale had a good discrimination power. An experiment was designed to test the relationship of SNW and the actual work behaviors of the respondents. The respondents' action in completing a task was chosen as working behavior index. 4 hypotheses were tested: 1) higher obligation orientation subjects are more likely to complete tasks no matter overtime; 2) scheduled tasks are more likely to be completed no matter overtime; 3) the obligation norm about working is positively correlated with general obligation norms; and, 4) external motivtors will enhance lower obligation orientation subjects' working motivation more than higher obligation orientation subjects' the results verified hypothesis 1 and 3, but didn't support hypothesis 2 and 4 these findings will have great implication in administrating.