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An unreported unprecedented spike of ∼μs line-width, followed by an overshoot, was discovered at the rising edge of transient electroluminescence (TEL) from guest-doped organic light-emitting diodes with strong electron-donating abilities from the host carbazole groups. By changing the device structures and TEL measurement parameters, a series of experimental results demonstrate that this TEL spike is not related to exciton interactions such as singlet–triplet and triplet–triplet annihilations but originated from the radiative recombination of pre-stored electrons with injected holes. Surprisingly, these pre-stored guest electrons do not come from the energy-level traps in the host–guest systems; instead, the guest molecules receive the electrons transferred from the host carbazole groups due to their strong electron-donating abilities. Moreover, the observed spikes show rich and extraordinary temperature dependences. Based on the detailed understanding of the spike formation mechanism, we have proposed the requirements for the occurrence of spike and realized the artificial adjustments of the spike intensity. For instance, the instantaneous luminescent intensity of this spike can reach over 80 times the magnitude of the TEL plateau. Accordingly, this work deepens the physical understanding of this novel spike in TEL and paves the way for fabricating an electro-optic sensor to detect instantaneous weak current signals.

The sensitization properties of rubrene with strong triplet fusion (TF) and the physical mechanisms of the enhanced electroluminescence efficiency were studied from a series of rubrene–DCJTB–codoped OLEDs. Although they have the same electroluminescence spectra, the target device containing rubrene as a sensitizer (mCP/5% rubrene/5% DCJTB) was more efficient than the reference device (mCP/5%DCJTB). This is because in the target device, besides the direct charge injection (DCI) onto DCJTB dopant, there exists reverse intersystem crossing (RISC) of triplet excitons via strong TF of rubrene and the following multiple energy-transfer channels sensitized by rubrene. Importantly, the EL was stronger from rubrene sensitization than from the DCI of DCJTB. Moreover, both the EL efficiency and the sensitization channel were enhanced at high sensitizer concentration, large bias current, and low operating temperature. These findings demonstrate that traditional fluorescent rubrene can be used as an effective sensitizer to realize high-performance OLEDs.

Magneto-electroluminescence (MEL) was used to investigate the effect of high temperature on exciton processes and the structure of tris (8-hydroxyquinoline) aluminum-based organic light-emitting diodes (OLEDs). The MEL changed little over temperatures ranging from 300 to 420 K and then increased significantly at 440 K. Optical microscopy, atomic force microscopy, and current-density vs voltage curves indicated that the sharp increase was caused by numerous traps generated in the emissive layer. These traps limited the diffusion of polaron pairs and excitons and ultimately promoted intersystem crossing. Hence, the device had a critical ambient temperature above which the trap-assisted intersystem crossing adversely affected the OLED performance. MEL is a real-time, noncontact method to monitor exciton processes and the device structure of OLEDs in high temperature environments.

The first account of the effects of wetland reclamation on soil nematode assemblages were provided, three sites in Heihe River Basin of Northwest China, that is grass wetland (GW), Tamarix chinensiswetland (TW) and crop wetland (CW) treatments, were compared. Results showed that the majority of soil nematodes were presented in the 0–20 cm soil layers in CW treatments, followed by in the 20–40 cm and 40–60 cm layers in GW treatments. Plant-feeding nametodes were the most abundant trophic groups in each treatment, where GW (91.0%) > TW (88.1%) > CW (53.5%). Generic richness (GR) was lower in the TW (16) than that in GW (23) and CW (25). The combination of enrichment index (EI) and structure index (SI) showed that the soil food web in GW was more structured, and those in TW was stressed, while the enrichment soil food web was presented in the CW treatment. Several ecological indices which reflected soil community structure, diversity, Shannon-Weaver diversity (H′), Evenness (J′), Richness (GR) and modified maturity index (MMI) were found to be effective for assessing the response of soil namatode communities to soil of saline wetland reclamation. Furthermore, saline wetland reclamation also exerted great influence on the soil physical and chemical properties (pH, Electric conductivity (EC), Total organic carbon (TOC), Total nitrogen (Total-N) and Nitrate Nitrogen (N-NO3–)). These results indicated that the wetland reclamation had significantly effects on soil nematode community structure and soil properties in this study.

This paper examines the phrase #bindersfullofwomen as an example of searchable talk in the microblogging sphere of Twitter. The data were collected and sampled in terms of its temporal development on Twitter. Drawing on the content analysis combined with descriptive statistics, the paper identified and compared the Twitter users as Journalist users and Ordinary users who are engaged with Twitter communication. It shows that Journalists tend to initiate the topic at the early stage of communication. Soon afterwards, the Ordinary participants dominate the Twitter communication. The tweets are textually characterized into three different categories on the formal grounds: Hashtags, Hashtags plus texts and anything with a link" or "a retweet", in the heteroglossic context of micro-blogging sphere. The categorization of tweets contributes as a methodology to distinguish the discourse practice performed by different Twitter users. The results show that both Journalist and Ordinary favor to post the informative tweets throughout the sampled period. The quantity of interactive tweets is becoming less favorable; however, in contrast, the tweets on the indeterminate plane gain high popularity from the early phase of the period. Our comparison indicates that the boundary between Journalist and Ordinary seems to be indistinct in terms of their contents.

AbstractIn [35,36], we presented an h-adaptive Runge-Kutta discontinuous Galerkin method using troubled-cell indicators for solving hyperbolic conservation laws. A tree data structure (binary tree in one dimension and quadtree in two dimensions) is used to aid storage and neighbor finding. Mesh adaptation is achieved by refining the troubled cells and coarsening the untroubled “children”. Extensive numerical tests indicate that the proposed h-adaptive method is capable of saving the computational cost and enhancing the resolution near the discontinuities. In this paper, we apply this h-adaptive method to solve Hamilton-Jacobi equations, with an objective of enhancing the resolution near the discontinuities of the solution derivatives. One- and two-dimensional numerical examples are shown to illustrate the capability of the method.

In this work, we study the strong decay of the newly observed Pcs(4459), assuming that it is a pure molecular state. Considering two possible spin-parity assignments JP= 1/2−and JP= 3/2−, the partial decay widths of the molecular state into J/ψΛ, Ds−Λc+, and final states through hadronic loops are evaluated with the help of the effective Lagrangians. In comparison with the LHCb data, the S-wave molecular with JP= 1/2−assignment for Pcs(4459) is supported by our study, while the Pcs(4459) in spin-parity JP= 3/2−case may be explained as an S-wave coupled bound state with lager component. In addition, the calculated partial decay widths with JP= 1/2−molecular state picture indicate that allowed decay mode, , may have the biggest branching ratio. The experimental measurements for this strong decay process could be a crucial test for the molecule interpretation of the Pcs(4459).