Dendrimers as Dopant Atom Carriers

Properties of modern semiconducting transistors and future electron or quantum devices are essentially determined by single dopant atoms. How to precisely control the individual dopant position is one of the key factors to advance these technologies. In this chapter, we first briefly introduce the research progress in single dopant devices. To fabricate single dopant devices at large scale, we then overview our previous propose to control the locations of single dopants by self-assembly of large molecules (polyglycerols) with each carrying one dopant atom. The synthesis process, doping properties, and challenges of the molecular doping technique will be thoroughly elaborated before we conclude this chapter

Gas Sensing Properties of Single Conducting Polymer Nanowires and the Effect of Temperature

We measured the electronic properties and gas sensing responses of template-grown poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS)-based nanowires. The nanowires have a "striped" structure (gold-PEDOT/PSS-gold), typically 8um long (1um-6um-1um for each section, respectively) and 220 nm in diameter. Single-nanowire devices were contacted by pre-fabricated gold electrodes using dielectrophoretic assembly. A polymer conductivity of 11.5 +/- 0.7 S/cm and a contact resistance of 27.6 +/- 4 kOhm were inferred from measurements of nanowires of varying length and diameter. The nanowire sensors detect a variety of odors, with rapid response and recovery (seconds). The response (R-R0)/R0 varies as a power law with analyte concentration.Comment: 4 figures 8 pages, add 2 reference

Introducing a new concept: Psychological capital of older people and its positive effect on mental health

ObjectiveThis study aimed to explore the structure of psychological capital (PsyCap) and its positive effects on mental health among older people.MethodsStudy 1 used grounded theory to analyze the semi-structured interviewing data of 17 Chinese older people (60–96 years old) to develop a primary PsyCap questionnaire for older people. Study 2, respectively, applied exploratory factor analysis (EFA) with 198 Chinese older people (M = 69.2; SD = 6.685) and confirmatory factor analysis (CFA) with 370 Chinese older people (M = 73.84; SD = 9.416) to test a seven-factor structure for PsyCap. Study 3 used 328 participants (M = 79.73; SD = 9.073) to examine the correlation between PsyCap and mental health.ResultsStudy 1 identified that PsyCap of older people contains ‘resilience,’ ‘self-efficacy,’ ‘optimism,’ ‘ease and content,’ ‘gratitude and dedication, ‘wisdom,’ and ‘meaning in life’ and generated a primary seven-factor questionnaire. Study 2 proved the overall and internal structure reliability of PsyCap were good (Cronbach’s alphas ranged 0.809 ~ 0.935), and the seven-factor measurement model fitted the data well (χ2/df = 2.07, RMSEA = 0.05, RMR = 0.05, CFI = 0.95, IFI = 0.95, TLI = 0.94, NFI = 0.91). The PsyCap scale was also proved to an excellent convergent validity, discriminant validity, calibration validity, and measurement invariance across different groups. Study 3 found that PsyCap and its seven factors significantly correlated with depression (r = −0.419 ~ −0.163, p < 0.01) after controlling the demographic variables.ConclusionThese findings provide a reliable and valid assessment for quantitative empirical research of PsyCap among older people and show significant impacts on mental health among older people, which offers new insight into improving mental health from the perspective of positive psychology

Dielectrophoretically Assembled Polymer Nanowires for Gas Sensing

We measured the electronic properties and gas sensing response of nanowires containing segments of poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) that were synthesized using anodic aluminum oxide (AAO) membranes. The nanowires have a "striped" structure of gold-PEDOT/PSS-gold and are typically 8 um long (1 um-6 um-1 um for each section, respectively) and 220 nm in diameter. Dielectrophoretic assembly was used to position single nanowires on pre-fabricated gold electrodes. A polymer conductivity of 11.5 +/- 0.7 S/cm and a contact resistance of 27.6 +/- 4 kOhm were inferred from resistance measurements of nanowires of varying length and diameter. When used as gas sensors, the wires showed a resistance change of 10.5%, 9%, and 4% at the saturation vapor pressure of acetone, methanol and ethanol, respectively. Sensor response and recovery were rapid (seconds) with excellent reproducibility in time and across devices. "Striped" template-grown nanowires are thus intriguing candidates for use in electronic nose vapor sensing systems.Comment: 18 pages 6 figure