Improvement in Device Performance and Reliability of Organic Light-Emitting Diodes through Deposition Rate Control

We demonstrated a fabrication technique to reduce the driving voltage, increase the current efficiency, and extend the operating lifetime of an organic light-emitting diode (OLED) by simply controlling the deposition rate of bis(10-hydroxybenzo[h]qinolinato) beryllium (Bebq 2 ) used as the emitting layer and the electron-transport layer. In our optimized device, 55 nm of Bebq 2 was first deposited at a faster deposition rate of 1.3 nm/s, followed by the deposition of a thin Bebq 2 (5 nm) layer at a slower rate of 0.03 nm/s. The Bebq 2 layer with the faster deposition rate exhibited higher photoluminescence efficiency and was suitable for use in light emission. The thin Bebq 2 layer with the slower deposition rate was used to modify the interface between the Bebq 2 and cathode and hence improve the injection efficiency and lower the driving voltage. The operating lifetime of such a two-step deposition OLED was 1.92 and 4.6 times longer than that of devices with a single deposition rate, that is, 1.3 and 0.03 nm/s cases, respectively

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Near-Field Revelation of Nano-Array Plasmonics,

[[sponsorship]]原子與分子科學研究所[[note]]已出版;有審查制度;具代表

Solvation Ultrafast Dynamics of Reactions. 9. Femtosecond Studies of Dissociation and Recombination of Iodine in Argon Clusters

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Femtosecond pH jump: dynamics of acid—base reactions in solvent cages

Studies are reported of the dynamics of proton-transfer reactions, with sub-picosecond time resolution, in solvent cages. The acid—base system studied in a molecular beam is 1-naphthol as a solute and ammonia (or water) as a solvent, with the number of solvent molecules (n) varying. At the threshold (n=3) for proton transfer we examine the accurate form of the decay, which has an apparent biexponential character, and we relate it to the nature of deprotonation and recombination. From studies of the effect of the total energy, isotope substitution and solvent number (n), we discuss the nature of the transfer and the interplay between the local structure of the base solvent and the dynamics

Analysis of Labial and Lingual Strength among Healthy Chinese Adults in Taiwan

This study collected 11 parameters regarding the labial and lingual strength for maximum isometric and swallowing tasks among 150 healthy Chinese adults in Taiwan. Measurements were performed using the Iowa Oral Performance Instrument (IOPI). All of the labial and lingual strength parameters were measured three times. The maximal value of three trials represents the pressure of every parameter. The overall mean (±standard deviation) and maximum isometric pressures of the lips, anterior tongue, and posterior tongue were 24.81 ± 5.64, 55.95 ± 14.13, and 53.23 ± 12.24 kPa, respectively. The mean value of posterior tongue strength was less than that of the anterior tongue by approximately 5%. The percentages of maximum isometric tongue pressure during the swallowing of saliva and water were 85% and 80% for the anterior tongue and 90% and 81% for the posterior tongue, respectively. The average endurances for the anterior tongue and posterior tongue were 13.86 ± 7.08 and 10.06 ± 5.40 s, respectively. The maximum isometric pressures were greater than both the saliva and water swallowing pressures, and the saliva swallowing pressures were greater than the water swallowing pressures. A value of 33 kPa in maximum isometric pressure could serve as a demarcation of weak tongue strength for healthy Chinese adults. As for the repeated trials of labial and lingual strength, there were no statistically significant differences for any of the pressures obtained from the 11 labial and lingual strength parameters. The normative data can be used for the objective assessment of labial and lingual strength in healthy Chinese adults

Deciphering Anomalous Raman Features of Regioregular Poly(3-hexylthiophene) in Ordered Aggregation Form

Poly­(3-hexylthiophene) (P3HT), being a prototypic conjugated polymer, bears a high charge mobility that is sensitive to its packing configuration in the condensed phase. Despite its extensive experimental study with X-ray diffraction, its specified packing structure still remains stymied. This study searched for possible structures of crystalline P3HT and identified the one that holds a simulated Raman spectrum most approximate to the experimental one of ordered P3HT aggregates in the frozen solvent. The spectral correspondence shows that the Raman-active C–C stretch peak exhibits a red shift in frequency, while the CC stretch peak displays a blue shift as the layer planarity of P3HT is relaxed. Moreover, the CC peak splits into two when adjacent thiophene rings in the P3HT chain hold a dihedral angle of 22° with respect to each other. This study demonstrates that Raman spectroscopy plus first-principles simulations can serve as a powerful tool to resolve fine structures of molecular crystals