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CzDBA is a donor-acceptor-donor (D-A-D)-type of thermally activated delayed fluorescence (TADF) material that has been recently reported in the literature; it has better luminous performance than ordinary D-A-type TADF materials. To explore the microscopic processes involved in CzDBA-based light-emitting devices, we fabricated two kinds of devices with light-emitting layers of pure CzDBA and 4CzTPN-Ph films and measured their magneto-luminescence (MEL) and magnetic conductance (MC) at room temperature. Experimental results show that although both of them contain carbazole groups, their MEL traces present two different line shapes; the former (CzDBA-based OLEDs) exhibits positive MEL curves dominated by intersystem crossing processes (ISC), whereas the latter depicts negative MEL traces governed by reverse ISC (RISC). In addition, CzDBA-based OLEDs have the same line shapes of MEL and MC traces. To investigate this anomalous magnetic-field response in CzDBA further, we prepared a doped device with a light-emitting layer of mCBP: x %CzDBA. Experimental results show that compared with devices with pure CzDBA as an emission layer, doped devices exhibit similar MEL and MC line types but have opposite temperature-dependent MEL traces. Detailed analyses related to MEL and MC traces show that the ISC process of polaron pairs dominates pure CzDBA devices, making their MEL values always positive. However, the doping of CzDBA into an mCBP host results in a strong exciton energy transfer (ET) process in the doped devices; this ET process is suppressed at low temperature, leading to a weakened RISC effect and an abnormal temperature effect different from that of pure CzDBA devices. In addition, the competition of the energy transfer process between host and guest and the trapping effect of charge carriers produce a nonmonotonic change in the MEL amplitude of the doped device by increasing the dopant concentration. This change further proves the correctness of the proposed microscopic mechanisms for these CzDBA-based OLEDs. This work is beneficial to the further understanding of the evolution mechanisms of the microscopic processes in devices based on excellent CzDBA luminescent materials recently discovered in literature.

Although the host material has been proved to be a crucial factor affecting the occurrence of the high-level reverse intersystem crossing (HL-RISC, T2,rub → S1,rub) process in rubrene-doped organic light-emitting diodes (OLEDs), the roles of the charge-transporting layers on this amazing process are still unclear. Very interestingly, herein, we found that the efficient conversion from intersystem crossing (ISC) to HL-RISC is observed by tuning the triplet energies of hole- and electron-transporting layers (HTL and ETL) in rubrene-doped devices. Specifically, when the triplet energies of ETL, rubrene guest, and HTL satisfy the criterion of E(T1,ETL) < E(T2,rub) < E(T1,HTL), the conversion process can be observed under various current and temperature conditions, which can be reasonably explained by the weak energy-loss channel from T2,rub to T1,ETL states and the competition effects of excited states in the ETL and guest. Otherwise, ISC (HL-RISC) will dominate in devices due to the existence (non-existence) of energy-loss channels from T2,rub to T1,HTL states. Furthermore, very importantly, by inserting appropriate HTL or ETL materials with high triplet energies into the control devices with energy-loss channels, we found that the full confinement of E(T2,rub) indeed facilitates the HL-RISC process. Our work deepens the cognition of the HL-RISC process and provides an effective method to achieve the HL-RISC process in organic optoelectronic devices.

An accurate troubled-cell indicator (TCI) is always desired by the discontinuous Galerkin methods for solving nonlinear hyperbolic conservation laws. In this paper, we will design a new TCI using K...

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 outbreak of the COVID-19 pandemic has generated a spectacular rise in social media communication and an unprecedented avalanche of global conversation. This paper traces the emergence of the racist term “Chinese virus” used by the President of the United States, Donald Trump, on the Western social media platform Twitter and its reception and recontextualization on Chinese social media. Creative bilingual responses fusing English and Chinese resulted in a popular searchable meme “#用中式英语跨文化交流#” (“#Chinglish used for cross-cultural communication#”), on Weibo, a Chinese social media platform. Such linguistic creativity involves a variation of swears to mock and condemn the racist phrase. Formally, linguistic practices such as self-coinage, transliteration, verbal repetition, and acronyms can be observed. Functionally, the recontexualizations evidence a defensive ideology linked to nationalism and modernism. Ultimately, combatting the English racist term “Chinese virus” with a creative mixture of English and Chinese demonstrates how English has become ever more decentered during the COVID-19 pandemic.

Recently, exciplex-based organic light-emitting diodes (OLEDs) have become hot topics in organic optoelectronics in terms of improving luminescent efficiency by controlling the energy transfer of excitons. This is because the formation of an exciplex can result in a small energy level difference, Δ E ST between singlet and triplet exciplex states, and with the assistance of external thermal energy, nonradiative triplet exciplex states can transform into radiative singlet ones through the so-called reverse intersystem crossing (RISC) process. Moreover, this RISC process will enhance the luminescence of OLEDs based on host–guest systems through energy transfer from exciplexes to dopants. The energy-transfer capability of OLEDs will affect the number of polaron pairs and exciplexes in host–guest systems. Indeed, it is important to find an effective probing technique for simply studying these microscopic processes. Many literature reports have demonstrated that organic magneto-electroluminescence (MEL) traces could be used for exploring and understanding the formation of and interactions between polaron pairs, excitons, and/or exciplexes. This is because MELs exhibit sensitive fingerprint responses to intersystem crossing (ISC), high-level reverse intersystem crossing (HL-RISC), singlet exciton fission (SF), and triplet exciton fusion (TF). In this study, four different OLEDs with various exciplex hosts have been fabricated, and their MEL curves have been measured at different currents and temperatures. Four exciplexes with different triplet exciton energies were used as host materials, and Rubrene was used as a fluorescent dopant. To study the exciton energy transfer and luminescence mechanism in such doping systems, we fully analyzed the emission spectra of the host materials, absorption spectrum of the guest material, and triplet exciton energy of the host and guest materials. The experimental results show that when the combined energy of the exciplex’s triplet excitons (EX3) is lower than that of the second-order triplet excitons (T2,Rub) of the Rubrene dopant, the MEL curve is dominated by the B -mediated ISC from host polaron pairs (PP1→PP3). Otherwise, the MEL curves are composed of both low-field and high-field components. The low-field components of MEL are governed by the B -mediated HL-RISC (T2,Rub→S1,Rub) process of the Rubrene molecules, while the high-field components of MEL are the result of the TF process between the triplet excitons of Rubrene (T1,Rub+T1,Rub→S1,Rub+S0,Rub) at high current densities or by the SF process of singlet excitons (S1,Rub+S0,Rub→T1,Rub+T1,Rub) at low current densities. In addition, these microprocesses will be markedly affected by the operational temperature and bias-current of the devices, because the Rubrene triplet excitons have long lifetimes (T1,Rub and T2,Rub) at low temperatures, and large quantities of Rubrene excitons are produced at high current densities. Moreover, the energy level difference between the single and triplet excitons of the host and guest will regulate the energy transfer from the former to the latter, i.e., the combined energy from the singlet excitons of the host being higher than that of the guest is the requirement of efficient Forster energy transfer where the smaller is the triplet exciton energy difference between the host and guest, the stronger is the Dexter energy transfer. Consequently, the energy-transfer mechanism will affect the utilization rate of the triplet excitons by adjusting the quantity and longevity of the singlet or triplet excitons on the Rubrene molecules, which ultimately affects the luminous intensity of the device. This work is helpful for further understanding the microscopic mechanisms of Rubrene-based devices and provides a theoretical reference for enhancing their luminescent efficiencies.

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–codope...

Simple Summary Hourly manure coverage proportion and area on the manure belt are key parameters for estimating ammonia emissions in poultry houses in order to provide environmental control suggestions and achieve the goals of precision poultry farming. In this study, experimental measurements were performed, and binary images were applied to provide new insights into the projected hourly manure coverage area on the manure belt at different layer hen ages. It was demonstrated that manure coverage proportion and area measured at different laying hen ages showed similar trends and values with four distinct stages within 48 h. In addition, statistical analyses found no significant correlation between the hourly increment of manure weight and the hourly increment of manure coverage proportion. The results from the present study are expected to serve as a fundamental input parameter for ammonia emission modeling to more accurately simulate the hourly indoor environment and provide effective mitigation strategies. Abstract The main advantage of having livestock, for example, the laying hens, in a controlled environment is that the optimum growth conditions can be achieved with accuracy. The indoor air temperature, humidity, gases concentration, etc., would significantly affect the animal performance, thus should be maintained within an acceptable range. In order to achieve the goals of precision poultry farming, various models have been developed by researchers all over the world to estimate the hourly indoor environmental parameters so as to provide decision suggestions. However, a key parameter of hourly manure area in the poultry house was missing in the literature to predict the ammonia emission using the recently developed mechanistic model. Therefore, in order to fill the gap of the understanding of hourly manure coverage proportion and area on the manure belt, experimental measurements were performed in the present study using laying hens from 10 weeks age to 30 weeks age. For each test, six polypropylene (pp) plates were applied to collect the manure dropped by the birds every hour, and photographs of the plates were taken at the same time using a pre-fixed camera. Binary images were then produced based on the color pictures to determine the object coverage proportion. It was demonstrated that for laying hens of stocking density around 14 birds/m2, the manure coverage proportion at the 24th hour after the most recent manure removal was about 60%, while the value was approximately 82% at the 48th hour. Meanwhile, for laying hens at different ages, the hourly increment of manure coverage proportion showed a similar pattern with four distinct stages within 48 h. The statistical analyses demonstrated no significant correlation between the hourly increment of manure weight and the hourly increment of manure coverage proportion. Finally, prediction models for estimating the hourly manure coverage proportion on the manure belt in typical laying hen houses were provided.

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 di...

To explore the microscopic mechanism of singlet exciton splitting (${\\rm~S}_{1}+{\\rm~S}_{0}\\to~{\\rm~T}_{1}+~{\\rm~T}_{1}$, STT) and luminescence in Rubrene, a phosphorescent material Ir(ppy)$_{3}$ with strong spin-orbit coupling (SOC) and green emission was selected and mixed into Rubrene thin films with different proportions to fabricate a series of luminescent devices. By measuring the magneto-electroluminescence (MEL) and current-luminescence ($I$-$B$) curves of the devices under different temperatures and currents, we found that the MEL profiles of light-emitting devices with different mixing ratios at room temperature show an STT fingerprint characteristic curve of magnetic field modulation. MEL amplitude first increases and then decreases with increased mixing ratio, whereas luminescence intensity increases monotonously. This is different from conventional Rubrene doped devices (such as mCP: $y$%Rubrene) which show STT increases with increasing concentration but with decreasing luminescence . By analyzing the singlet and triplet energy levels and emission spectra of Ir(ppy)$_{3}$ and absorption spectra of Rubrene, it can be seen that aside from Rubrenes molecular spaces influence on the STT process, intersystem crossing (ISC) caused by the strong SOC of Ir(ppy)$_{3}$ and energy transfer processes between the T$_{1}$ exciton of Ir(ppy)$_{3}$ and the S$_{1}$ exciton of Rubrene are also included in the devices. The combined action of these three micro-mechanisms leads complex MEL and luminescence changes in the device, and the devices current density and working temperature also have a good regulatory effect on them. Obviously, this study helps with understanding of the microscopic process and its evolution mechanism based on Rubrene optoelectronic devices.

In this work, we study the strong decay of the newly observed $P_{cs}(4459)$ assuming that it is a pure $\Xi_c\bar{D}^{*}$ molecular state. Considering two possible spin-parity assignments $J^P=1/2^{-}$ and $J^P=3/2^{-}$ the partial decay widths of the $\Xi_c\bar{D}^{*}$ molecular state into $J/\psi{}\Lambda$, $D_s^{-}\Lambda_c^{+}$, and $D\Xi_c^{(')}$ final states through hadronic loops are evaluated with the help of the effective Lagrangians. In comparison with the LHCb data, the spin-party $J^P=1/2^{-}$ the assignment is preferred while this of $J^P=3/2^{-}$ is disfavored. The $P_{cs}(4459)$ in spin-parity $J^P=3/2^{-}$ case maybe explained as $S$-wave coupled bound state with lager $\Xi_c\bar{D}^{*}$ component. In addition, the calculated partial decay widths with $J^P=1/2^{-}$ $\Xi_c\bar{D}^{*}$ molecular state picture indicates that allowed decay mode, $D\Xi_c^{'}$, 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 $P_{cs}(4459)$.

Last year, the state, which is cataloged in the Particle Data Group (PDG) with only one star, was reported again in the final state by the Belle Collaboration. Its properties, such as the spectroscopy and decay width, cannot be simply explained in the context of conventional constituent quark models. This inspires an active discussion on the structure of this resonance. In this paper, we study the radiative decays of the newly observed assuming that it is a meson-baryon molecular state of and with spin-parity developed in our previous study. The partial decay widths of the molecular state into and final states through hadronic loops are evaluated using effective Lagrangians. The partial widths for is evaluated to be approximately keV, which may be accessible for the LHCb experiment. If is a molecule, the radiative transition strength is considerably small and the decay width is of the order of 0.01 eV. Future experimental measurements of these processes can be useful to test the molecule interpretations of the .

Reverse intersystem crossing (RISC) unexpectedly dominates the interconversion of polaron pairs in the traditional fluorescent material 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidin-4-yl-vinyl)-4H-pyran (DCJTB), with a large energy gap (\ensuremath{\Delta}${E}_{\mathrm{ST}}$) between singlet and triplet excitons, by employing the magnetoelectroluminescence detection technique. Contrary to RISC among excitons with small \ensuremath{\Delta}${E}_{\mathrm{ST}}$ from conventional thermally activated delayed fluorescence, these RISC processes are increased at a high current density and low temperature, which is ascribed to an enhanced direct charge-trapping effect and prolonged lifetime of the triplet-polaron pair, respectively. More intriguingly, the conversion of RISC to ISC is observed by reducing the electron-hole distance of polaron pairs via increasing the concentration of DCJTB dopant. Furthermore, the host must have a high triplet exciton energy to prevent energy back-transfer of the triplet exciton from the guest to the host and ensure efficient occurrence of the RISC process. The RISC-dominated device has a markedly higher external quantum efficiency than that of the ISC-governed one. This work not only deepens the microscopic understanding of the spin-pair states of red-light-emitting DCJTB-doped devices, but also provides a useful method to utilize a conventional fluorescent dopant for designing high-efficiency organic light-emitting diodes.

Very recently, three new structures $\Xi_c(2923)^0$, $\Xi(2938)^0$, and $\Xi(2964)^0$ at the invariant mass spectrum of $\Lambda_c^{+}K^{-}$ observed by the LHCb Collaboration triggers a hot discussion about their inner structure. In this work, we study the strong decay mode of the newly observed $\Xi_c$ assuming that the $\Xi_c$ is a $\bar{D}\Lambda-\bar{D}\Sigma$ molecular state. With the possible quantum numbers $J^p=1/2^{\pm}$ and $3/2^{\pm}$, the partial decay widths of the $\bar{D}\Lambda-\bar{D}\Sigma$ molecular state into the $\Lambda_c^{+}K^{-}$, $\Sigma_c^{+}K^{-}$,and $\Xi_c^{+}\pi^{-}$ final states through hadronic loop are calculated with the help of the effective Lagrangians. By comparison with the LHCb observation, the current results of total decay width support the $\Xi(2923)^0$ as $\bar{D}\Lambda-\bar{D}\Sigma$ molecule while the decay width of the $\Xi_c(2938)^0$ and $\Xi(2964)^0$ can not be well reproduced in the molecular state picture. In addition, the calculated partial decay widths with $S$ wave $\bar{D}\Lambda-\bar{D}\Sigma$ molecular state picture indicate that allowed decay modes, $\Xi_c^{+}\pi^{-}$, may have the biggest branching ratios for the $\Xi_c(2923)$. The experimental measurements for this strong decay process could be a crucial test for the molecule interpretation of the $\Xi_c(2923)$., Comment: arXiv admin note: text overlap with arXiv:1002.0218 by other authors

We fabricated quantum-well organic light-emitting diodes (QW-OLEDs) based on thermally activated delayed fluorescence (TADF) and measured their magneto-electroluminescence (MEL) and magneto-conductance (MC) curves over various magnetic field ranges. When the number (N) of QWs was 7, the MC curves showed a flat structure within the magnetic field range 5 < |B| < 20 mT. The flat structure vanished with the use of a higher electron mobility material, which we attribute to competition between the dissociation of triplet excitons by holes and scattering of electrons by triplet excitons in the QW-TADF-OLEDs. In addition, when N ranged from 3 to 9, the MEL curves in the range |B| < 10 mT presented a W-like line-shape and the MC curves in the range |B| < 10 mT showed variation of their line-shape from W-like to negative Lorentzian-type; however, the B-dependent efficiency Mη (i.e., MEL–MC) curves in the range |B| < 10 mT, which were independent of N, showed a V-type line-shape. Our analysis suggests that these magnetic response behaviors depend on the combined effects of intersystem crossing of polaron pairs, reverse intersystem crossing of charge transfer excitons, and triplet-charge interactions under an external field B. This work provides insight into spin-pair dynamic mechanisms occurring within QW-TADF devices and suggests potential applications for a single OLED with integrated magnetic, optical, and electric properties.

An in situ heating method was used to investigate the effect of high temperature on the magneto-electroluminescence (MEL) of rubrene-based organic light-emitting diodes. The change of MEL indicated that the microscopic mechanism of the device converted from singlet fission (SF) to intersystem crossing (ISC) at 380 K. Analysis of the surface morphology, electroluminescence spectrum, and current–voltage curve of the device suggested that the SF-to-ISC conversion was caused by a large number of exciton traps generated in the organic layers of the device. These traps blocked the movement of excitons, which suppressed SF. By contrast, ISC was promoted by traps and became the main process. This work provides a detailed investigation of the dynamics of exciton evolution and deepens our understanding of electron–hole interaction mechanisms in organic devices at high temperature.

The thermally activated delayed fluorescence (TADF) material 2,3,5,6-tetrakis(3,6-diphenylcarbazol-9-yl)-1,4-dicyanobenzene (4CzTPN-Ph) and the conventional fluorescent dopant 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidin-4-yl-vinyl)-4H-pyran (DCJTB) were used to co-dope the host material 4,4'-bis(carbazol-9-yl)biphenyl (CBP) for the fabrication of TADF-assisted fluorescent organic light-emitting diodes (OLEDs). Some exceptional magnetic field effect (MFE) curves with abundant structures and four tunable components within a low magnetic field range (≤50 mT) were obtained, in sharp contrast to the maximum of two components observed in typical OLEDs. These MFE components were easily tuned by the injection current, dopant concentration, working temperature, and dopant energy gap, leading to a wide variety of MFE curve line shapes. The experimental results are attributed to the spin-pair state inter-conversions occurring in the device, including intersystem crossing (ISC) of CBP polaron pairs, ISC of 4CzTPN-Ph polaron pairs, reverse ISC (RISC) of 4CzTPN-Ph excitons, RISC of DCJTB polaron pairs, DCJTB triplet fusion, and DCJTB triplet-charge annihilation. Moreover, the exciton energy transfer processes among the host material and the guest dopants had a pronounced impact on the formation of these four components. This work gives a deeper understanding of the microscopic mechanisms of TADF-based co-doped systems for the further development of organic magnetic field effects in the extensive field of OLEDs.

Using the fingerprint magneto-electroluminescence trace, we observe a fascinating high-level reverse intersystem crossing (HL-RISC) in rubrene-doped organic light-emitting diodes (OLEDs). This HL-RISC is achieved from high-lying triplet states (T2,rub) transferred from host triplet states by the Dexter energy transfer to the lowest singlet states (S1,rub) in rubrene. Although HL-RISC decreases with bias current, it increases with lowering temperature. This is contrary to the temperature-dependent RISC from conventional thermally activated delayed fluorescence, because HL-RISC is an exothermic process instead. Moreover, owing to the competition of exciton energy transfer with direct charge trap, HL-RISC changes nonmonotonically with the dopant concentration and increases luminous efficiency to a maximum at 10% of rubrene, which is about ten times greater than that from the pure-rubrene device. Additionally, the HL-RISC process is not observed in bare rubrene-doped films because of the absence of T2,rub. Our findings pave the way for designing highly efficient orange fluorescent OLEDs.

Organic magnetic field effects (OMFEs), which primarily includes magneto-electroluminescence (MEL) and magneto-conductance (MC), is a non-contact, non-destructive and sensitive tool for probing the mechanisms that occur within in organic light-emitting diodes (OLEDs). Not only OMFEs can be used to detect charge transport, exciton evolution and luminescence mechanisms in OLEDs, and can also be used in magnetic devices, including magnetic switches, magnetic storage and magnetic sensors, etc. Stable magnetic devices are usually required for practical applications. There is a wealth of research that shows that doped devices exhibit improved stability when compared with non-doped devices, however, they always show weaker OMFEs responses. Therefore, it is important to achieve strong OMFEs responses from stable, doped devices. In this work, we have fabricated OLEDs using the thermally activated delayed fluorescence (TADF) material 2,3,5,6-tetrakis(3,6-diphenyl-carbazol-9-yl)-1,4-dicyanobenzene (4CzTPN-Ph) of different doping concentration as the dopant, and either tris-8-hydroxyquinoline aluminum (Alq3) and 4,4′- N , N ′-dicarbazole-biphenyl (CBP) as the host materials. The light-emitting layer in these OLEDs was Alq3: x % 4CzTPN-Ph (studied devices) or CBP:5% 4CzTPN-Ph (reference device). The MEL and MC curves from these devices were measured with different injection currents and doping concentrations at room temperature, and with varying temperatures at a constant injection current and doping concentration. Compared with the reduced OMFEs observed from the reference device, the studied devices exhibited increased amplitudes in their MEL and MC responses. For example, at an injection current of 150 μA at room temperature, the amplitude of the MEL from the studied device reached ~10% when exposed to a magnetic field of 300 mT, which was approximately 13 times larger than that observed from the reference device (~0.75%). The corresponding amplitude from the MC from the studied device was ~6% at 300 mT, which was approximately 50 times larger than that observed from the reference device (~0.12%). In addition, the MEL and MC responses from the studied devices were determined by the doping concentration. At a doping concentration of approximately 15%, the MEL and MC values from the studied devices at 300 mT reached maximum values of 13.4% and 9.3%, respectively. Both MEL and MC values from the studied device reduced with decreasing temperatures. Analysis of the energy levels and optical spectra from these studied devices indicated that the special energy level arrangement between the guest and host molecules resulted in a weak energy level trap. The external magnetic field suppressed the scattering of charges by triplet excitons, a channel for triplet-charge annihilation (TQA), which generated significant MEL and MC responses. Therefore, OMFEs that were stronger than those from the reference device were obtained. In addition, since TQA is affected by the concentration and mobility of triplet excitons and carriers, the doping concentration and working temperature can also mediate TQA by modifying the concentration and mobility of triplet excitons and carriers, which eventually affects the OMFEs. This work gives insight into the mechanisms that occur within 4CzTPN-Ph-based light-emitting diodes, and also importantly promotes practical applications of magnetic organic light-emitting diodes.

The discourse of broadcast news is shifting toward being more “conversational.” As a consequence, rather than assuming the traditional poker-face style of delivering news on television, news readers as televised personae are becoming more “informal” and “dialogic” in order to better relate to audiences. Eyebrow flashes, as a communicative resource in television news presentation, play an important part in construing the expressiveness of presentation and engaging with audiences. Drawing upon insights from nonverbal communication studies (especially the pragmatics of nonverbal communication) and discourse analysis, this paper explores the pragmatics of eyebrow flashes as a marker of expressivity in news delivery, and the interaction of eyebrow flashes with the verbal context, based on data collected from Chinese broadcast news in English. The analysis shows that eyebrow flashes are widely employed to initiate the theme of the agent in news messages (implicating “I know something”), to emphasize the focus of the news statements (implying “I am thinking now”), and to respond to the attributed statement (indicating “I want to know more”). Therefore, eyebrow flashes function to assist viewers in construing alignment with authors or reporters of news, as well as alignment with audiences. In addition, they serve to distill personal emotion to hybridize the institutional voice of news, thus rendering television news more “watchable” and engaging.

We investigate the possibility of studying the charmed-strange mesons ${D}_{s0}(2317)$ and ${D}_{s1}(2460)$ by kaon-induced reactions on a proton target in an effective Lagrangian approach. The production process is described by the $t$-channel ${D}^{0}$ and ${D}^{*0}$ exchanges, respectively. Our theoretical approach is based on the chiral unitary theory where the ${D}_{s0}(2317)$ and ${D}_{s1}(2460)$ resonances are dynamically generated. Within the coupling constants of the ${D}_{s0}(2317)$ to $KD$ and ${D}_{s1}(2460)$ to $K{D}^{*}$ channels obtained from chiral unitary theory, the total and differential cross sections of the ${K}^{\ensuremath{-}}p\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Lambda}}}_{c}{D}_{s0}(2317)$ and ${K}^{\ensuremath{-}}p\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Lambda}}}_{c}{D}_{s1}(2460)$ are evaluated. The $\overline{K}p$ initial state interaction mediated by Pomeron and Reggeon exchanges, which reduces the production cross sections of the ${D}_{s0}(2317)$ and ${D}_{s1}(2460)$, is also included. If measured in future experiments, the predicted total cross sections and specific features of the angular distributions can be used to test the (molecular) nature of the ${D}_{s0}(2317)$ and ${D}_{s1}(2460)$.

The spin polarization and spin–orbit coupling (SOC) in polymer light emitting diodes (PLEDs) with the active layer doped with Fe3O4 nanoparticles (NPs) were identified through magneto-electroluminescence (MEL). By comparing the MEL characteristics such as linewidth and magnitude between PLEDs with and without Fe3O4 dopant, we confirmed the existence of spin polarization, but ruled out the existence of SOC. Although the spin polarization is positive to electroluminescence, the brightness–current characteristics suggested that the current efficiency of the doped PLED does not improve. We attributed it to the current leakage caused by the Fe3O4 NPs in the active layer. This work is beneficial for us to further understand the effect of magnetic nanoparticle doping on the dynamic behavior of excitons and polaron pairs in organic semiconductor devices.