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Poly(styrene-sodium p-styrene sulfonate) microspheres with porous morphology were prepared by dispersion polymerization and seed swelling selecting two monomers of sodium p-styrene sulfonate and styrene, which are denoted as P(St-NaSS). The method is simple and easy to effectively control the pore structure microspheres. The SEM results showed that the surface morphology of P(St-NaSS) microspheres is in porous, and the diameter of pores is about 0.5 μm. In this paper, the influence of swelling time on the pore size was investigated. The SEM results indicated that the longer the swelling time, the larger the pore size of microspheres. The absorbing hybrids of swelled multi-porous P(St-NaSS) @MWCNTs and non-swelled P(St-NaSS)@MWCNTs with three-dimensional conductive network were assembled by π bond stacking effect, and study the strength of its absorption of electromagnetic waves. Compared with P(St-NaSS)@MWCNTs hybrids, the multi-porous P(St-NaSS) hybrids exhibited better absorbing performance, the reflection loss is -35.24 dB at 7.15 GHz at 2 mm thick, while the reflection loss of P(St-NaSS)@MWCNTs is -24.63 dB. The experimental results show that the existence of porous in wave-transparent microspheres played an important role in improving the impedance matching, increasing the path of multiple reflection scattering, which is beneficial to improve the absorption of MWCNTs. [ABSTRACT FROM AUTHOR]

As a promising technology for replacing the rule-based decision-making in region heating systems (RHS), deep reinforcement learning (DRL) is a practical solution to identify the optimal control for heating equipment. However, as residential customers perform more casual energy-consumption behaviors, the intermittency and volatility of heat demands make managing heat supply and storage much harder for DRL agents. This study proposes a novel predictive management method for campus heating systems (CHS) with air-source heat pumps (AHP) and thermostatic water tanks. The novelty of the proposed method lies in the combination of the heat demands forecasting model and DRL-based adaptively controlling for heat supply equipment, which is firstly proposed to improve the heating supply reliability and reduce the storage dependence for CHS. Specifically, an enhanced rule, namely minimum length hamming encoding, and an input array constructing method is introduced to deal with discrete feature data and then improve the accuracy of deterministic heat demands forecasting based on long-short term memory (LSTM), and the Kernel density estimation (KDE) are employed to obtain the prediction intervals (PIs) from H-step ahead heat demands forecasting series. Followed by these, the twin delayed deep deterministic policy gradient, a model-free DRL control algorithm, is adopted for adaptively adjusting the output flow rate of AHP and then the storage of the hot water tank. To demonstrate the validity of the proposed method, a case study is presented where a campus heat demands forecasting achieves a maximum accuracy gain of 4.52%, and an optimal AHP operating controlling determined from PIs achieves a better cost reduction and supply reliability, which is superior over the conventional method using real-time heat demands or deterministic forecasting results as input. • An adaptive management model for campus heating systems using the DRL algorithm is established. • Model predictive control theory is employed to cope with the intermittent nature of campus heat demands. • A more efficient encoding rule is proposed to improve the accuracy of LSTM-based deterministic demands forecasting. • Cosine function-based KDE is introduced to obtain the PIs of campus heat demands. • The proposed method can achieve a remarkable economic benefit and reduce the dependency on storage capacity for CHS. [ABSTRACT FROM AUTHOR]

Inspired by the flexibility of the bottom-up approach in choosing building blocks of two-dimensional (2D) materials, a π-conjugated metal complex nanosheet (HHTP-Cu) was successfully prepared by the coordination of the ligand 2,3,6,7,10,11-hexahydroxytriphenylene (HHTP) and Cu(II) ion at the water/oil interface. Field-emission scanning electron microscopy disclosed the large-size domain and transmission electron microscopy revealed the sheet morphology of the nanosheet. The flat and smooth surface was also confirmed by atomic force microscopy which further demonstrated the proposed structure. Energy dispersive X-ray spectroscopy was applied to verify the homogeneous distribution of the elements while X-ray photoelectron spectroscopy was used to investigate the composition of the nanosheet. [ABSTRACT FROM AUTHOR]

Post-rift tectonic activities have been widely observed in the northern continental margin of the South China Sea, especially during the late Miocene. Large numbers of faults became active. Unconformities, uplift of faulted blocks, sequence tilting, erosion along the Dongsha massif and canyon incision were also discriminated at this stage in the Pearl River Mouth basin (PRMB) and the area to the east. This tectonism has been named Dongsha Event. A number of hypotheses have been put forward to explain the mechanism of the Dongsha Event, such as high-velocity lower crustal flow, magmatic underplating, and arc-continent collision. To investigate the tectonic dynamics, sequence contact relationships, fault activities, and magmatism were analyzed along large numbers of seismic profiles that cover the eastern PRMB and Southwest Taiwan Basin. The timing, affected regions, and differences in the intensity of tectonic deformation were assessed, upon which the plate bending model was favored. In order to check the reasonableness of plate bending model, effective elastic thickness and other geodynamic parameters were calculated constrained by uplift area width and regarding the trench as sediment filling. A maximum Te value of ~27 km and a minimum value of ~4 km were obtained. Integrating with the former stress field calculation, we conclude that the Dongsha Event was mainly affected by subduction and collision of the South China Sea toward the Philippine Sea plate. This event commenced at about 10 Ma and peaked at around 3.6 Ma. Although the high effective elastic thickness required is a problem to be addressed, this research provides by far the most comprehensive evidences to the mechanism of the Dongsha Event. [ABSTRACT FROM AUTHOR]

Predator species of animal can absorb plant microRNA that can regulate target gene expression and physiological function across species. The herb Lycium barbarum , a traditional Chinese medicine, has a wide range of antitumor effects. However, there are no reports on the effects of microRNA derived from it on the cross-border regulation of renal cell carcinoma (RCC). We performed in vitro and in vivo experiments to explore the role and mechanism of the L. barbarum -derived microRNA miR166a (Lb-miR166a) in cross-border regulation of RCC. Our mRNA sequencing analysis showed that Lb-miR166a regulates the expression of various genes in tumor cells, including 1232 upregulated genes and 581 downregulated genes, which were enriched to 1094 Gene Ontology entries and 43 Kyoto Encyclopedia of Genes and Genomes pathways. In vitro cell experiments confirmed that Lb-miR166a can inhibit the proliferation of RCC cells, promote the apoptosis of tumor cells, and inhibit the invasion and metastasis of tumor cells by regulating the expression of related genes. Furthermore, our in vivo tumor-bearing experiment showed that subcutaneous tumor formation volume decreased in Lb-miR166a mice, along with the number of liver metastases. This study elucidates the role and mechanism of Lb-miR166a in RCC treatment (Fig. 1). Our results further mechanistically confirm the antitumor properties of L. barbarum. Our study may contribute to the clinical development of a targeted drug for RCC treatment. [ABSTRACT FROM AUTHOR]

Overhead transmission line detection based on deep learning of aerial images taken by UAVs has been widely investigated. Despite its success, it is limited by several factors, including inappropriate evaluation criteria and dramatic scaling of components in the images. To mitigate these issues, a relative mean Average Precision evaluation index is proposed to accurately measure the model's detection performance for smaller objects. A data enhancement strategy including multi‐scale transformation is adopted to alleviate the problem of drastic scaling. The existing Cascade RCNN target detection technology is enhanced by incorporating Swin‐v2 and a balanced feature pyramid to improve feature characterization capabilities, while side‐aware boundary localization is utilized to improve the positioning accuracy of the model. Experimental results demonstrate that the proposed method outperforms state‐of‐the‐art methods on CPLID and achieves 7.8%, 11.8%, and 5.5% higher detection accuracy than the baseline for mAP50, relative small and medium mAP, respectively. Additionally, the paper discusses the influence of adopted data enhancement on the robustness of the model. [ABSTRACT FROM AUTHOR]

Due to the outstanding penetrating detection performance of low-frequency electromagnetic waves, through-wall radar (TWR) has gained widespread applications in various fields, including public safety, counterterrorism operations, and disaster rescue. TWR is required to accomplish various tasks, such as people detection, people counting, and positioning in practical applications. However, most current research primarily focuses on one or two tasks. In this paper, we propose a multitask network that can simultaneously realize people counting, action recognition, and localization. We take the range–time–Doppler (RTD) spectra obtained from one-dimensional (1D) radar signals as datasets and convert the information related to the number, motion, and location of people into confidence matrices as labels. The convolutional layers and novel attention modules automatically extract deep features from the data and output the number, motion category, and localization results of people. We define the total loss function as the sum of individual task loss functions. Through the loss function, we transform the positioning problem into a multilabel classification problem, where a certain position in the distance confidence matrix represents a certain label. On the test set consisting of 10,032 samples from through-wall scenarios with a 24 cm thick brick wall, the accuracy of people counting can reach 96.94%, and the accuracy of motion recognition is 96.03%, with an average distance error of 0.12 m. [ABSTRACT FROM AUTHOR]

The faults characteristics of the lines in AC microgrid are weakened due to the fault resistance, which may refuse protection action. To solve the problems caused by different types of the faults through fault resistance (FTFR, the faults where the fault point resistance is greater than zero) in AC microgrid, a novel FTFR protection scheme based on the active power of 0-frame component or d-frame component consumed by fault resistance is proposed in this paper as the backup protection of FTFR. This proposed protection scheme utilizes the active power of 0-frame component or d-frame component consumed by fault resistance to identify internal FTFR and external faults. It performs well in grid-connected mode and islanded mode by adopting self-adaptive threshold and is not affected by the factors such as the fault position and the fault resistance value. The theoretical analysis and various simulations show that this protection scheme can identify and isolate different types of internal FTFR in AC microgrid with high reliability and high sensitivity. [ABSTRACT FROM AUTHOR]

We proposed a new readout method for single ring core direct current (DC) sensor to protect the DC power system.The principle of this readout method is based on the linear relationship between the permeability of magnetic ring core and the DC value when the DC value changes within a small range. We built a Pspice model of single magnetic ring core DC sensor based on the proposed method to prove its correctness. We performed simulations using this model under different conditions, including reference voltage, size of core, turns per coil, excitation period, and sampling frequency. The value of the tested DC can be fitted by one linear equation multiplied by a certain coefficient, and this result was consistent with the principle of the proposed readout method. Several trial manufactures of this sensor participated in a leakage detection test. The sensitivity and noise immunity of physical sensors can be enhanced by using a micro control unit (MCU) embedded system. The correctness of this method can be confirmed using measured data. [ABSTRACT FROM AUTHOR]

A cross-linkable conjugated polymer with bromo groups on the side chain has been developed and used as an anode interlayer to improve the active layer morphology and consequently enhance the device performance of polymer solar cells (PSCs). The polymer, PCDTBT-Br, has cross-linkable bromo groups attached to the side chain of a widely-used donor polymer, poly[N-9-heptadecanyl-2,7-carbazole- alt-5,5-(4,7-di-2-thienyl-2,1,3-benzothiadiazole)] (PCDTBT). The pendant bromo groups do not significantly change the LUMO/HOMO energy levels and absorption spectrum of the PCDTBT polymer backbone. PDCTBT-Br can crosslink under UV irradiation to give a robust film, which enables multilayer PSC device fabrication. Moreover, the much lower surface energy of PCDTBT-Br (20.4 mJ m−2) compared to PEDOT:PSS (91.6 mJ m−2) is beneficial for achieving optimal active layer morphology. As a result, with PCDTBT:[6,6]-phenyl-C71 butyric acid methyl ester (PC71BM) as the active layer, the PSC device with PCDTBT-Br as the underlying layer shows a power conversion efficiency (PCE) of 6.59 %, in comparison to a PCE of 5.86 % of the control device. The device performance enhancement is ascribed to the much improved phase separation with a fibrillar nanostructure in the active layer. [ABSTRACT FROM AUTHOR]

In order to clarify the trapping efficiency of different types of sex pheromone traps on populations of Spodoptera litura in soybean fields, three kinds of conventional traps, called YL-VT, YL-HEMT and YL-NMT, and types of traps equipped with a automatic catch monitoring mechanism, called AIM and AIM-lite-A, have been tested. These last two allow monitoring the diurnal and seasonal rhythms of the catches. From 5 August to 5 October 2020, each YL-VT trap caught an average of 84.4 heads of S. litura moths per day, which was significantly higher than the YL-HEMT (11.8 heads), YL-NMT (16.5 heads) and AIM (9.7 heads), which did not show significant differences between them. The half-life of pheromone attraction effect in YL-VT trap is about 17–20 days. Considering the number of trapping and the duration of pheromone attraction effect, YL-VT trap is the best. For efficient monitoring, the validity period is approximately 15 days. Among the causes that could explain its higher capture rate and efficiency, the YL-VT trap has the smallest and largest number of inlet devices, and in it, the lure core is located inside of the insect inlet device. Under different occurrence numbers of S. litura, the accuracy of the automatic count of AIM-lite-A is 90% greater than in the AIM trap. The diurnal rhythms of S. litura observed by AIM-lite-A show that S. litura have two active periods that are from 18:00 to 21:00 and from 23:00 to 4:00 at night and that the first active period may be affected by sunshine and temperature. The annual activity rhythm of S. litura monitored by AIM showed that the activity of S. litura was related to temperature, there were approximately 6 generations of S. litura in a year and that the activity peak was from August to September in Dangtu, China. AIM and AIM-lite-A can be used for the annual monitoring of S. litura population in soybean fields because of their automatic counting function. AIM can simultaneously record a variety of meteorological data, AIM-lite-A has higher accuracy and a lower cost, which can be selected according to different situations. In conventional traps, the trap YL-VT can be used for the population monitoring of S. litura in soybean fields and pest control in the field, especially in greenhouses and net rooms where organic soybeans are grown, due to its low cost and efficient trapping ability. [ABSTRACT FROM AUTHOR]

Conjugated polar polymers, in which the conjugated backbones are chemically anchored with functional polar side groups, can be processed with water/alcohol solvents, and thus multilayered device architectures can be easily realized via sequential solution processing of the toluene-soluble emissive polymer and alcohol-soluble electron-transporting polymer without intermixing. Regarding their use in organic optoelectronic devices, the success in achieving efficient charge injection and intimate contact between metal electrodes and organic semiconductors is very vital for enhancing the device performance. In this short review, it gives a brief review to neutral alcohol-soluble phosphonate-functionalized polyfluorene, mainly concerning the electronic structure at the phosphonate-functionalized polyfluorene/aluminum cathode interface and its successful application in multilayered polymer optoelectronic devices including polymer light-emitting diodes and polymer solar cells. [ABSTRACT FROM AUTHOR]

Abstract: The cytochrome P450 (CYP) is a superfamily of enzymes with oxidative function responsible for the metabolism of xenobiotics especially drug metabolism. CYP3A4, an extensive studied CYP isoform, plays crucial role in the metabolism of structurally diverse drugs. Furthermore, the drug–drug interaction resulted from the inhibition of CYP3A4 activity is of extreme importance for the treatment of disease and the development of new drug. In this study, using the method of the support vector machine (SVM) and three descriptors selected from the 153 descriptors we construct the models that can predict accurately the inhibitory effect of a compound on the activity of CYP3A4. By optimizing the parameters related to SVM, the cross validation correlation efficient of the model can achieve 0.71, which is higher than those of other models obtained using Artifical Neutral Network (ANN) and Partial least square (PLS) methods to our knowledge, and thus our model can present the important application in assessment of the potential toxicity of a drug as well as prediction of drug–drug interactions. [Copyright &y& Elsevier]

Abstract: We report enhanced polymer photovoltaic (PV) cells by utilizing ethanol-soluble conjugated poly(9, 9-bis (6′-diethoxylphosphorylhexyl) fluorene) (PF-EP) as a buffer layer between the active layer consisting of poly(3-hexylthiophene)/[6, 6]-phenyl C61-butyric acid methyl ester blend and the Al cathode. Compared to the control PV cell with Al cathode, the introduction of PF-EP effectively increases the shunt resistance and improves the photo-generated charge collection since the slightly thicker semi-conducting PF-EP layer may restrain the penetration of Al atoms into the active layer that may result in increased leakage current and quench photo-generated excitons. The power conversion efficiency is increased ca. 8% compared to the post-annealed cell with Al cathode. [Copyright &y& Elsevier]

Abstract: We have investigated the effects of thermal annealing before and after cathode deposition on poly(3-hexylthiophene) (P3HT)/[6,6]–phenyl C61-butyric acid methyl ester (PCBM) blend photovoltaic cells with different cathode buffer layers. The introduction of cathode buffer layer such as lithium fluoride (LiF) and calcium oxide (CaO) in pre-annealing cells can increase the open-circuit voltage (V oc) and the power conversion efficiency (PCE). Post thermal annealing after cathode deposition further enhanced the PCE of the cells with LiF/Al cathode, whereas the performance of the cell with CaO/Al cathode is decreased. It is found that the V oc and PCE can be largely enhanced when the post-annealed cell with Ca/Al cathode is exposed in air. This may attribute to the formation of CaO buffer layer, which favors increasing shunt resistance and V oc. Finally, a PCE of 4.60% is calculated under AM1.5G solar illumination at 100mW/cm2. [Copyright &y& Elsevier]

An efficient flexible top-emitting organic light-emitting diode (FTOLED) was developed on a thin steel foil. The FTOLED was constructed on the spin-on-glass (SOG)-coated steel substrate with an organic stack of NPB/Alq3 sandwiched by a highly reflective Ag anode and a semitransparent Sm cathode. An ultrathin plasma-polymerized hydrocarbon film (CFX) was interposed between the Ag anode and the NPB layer to enhance hole-injection, and an additional Alq3 layer was overlaid on the Sm cathode to increase light output. The FTOLED showed a peak efficiency of 4.4 cd/A higher than 3.7 cd/A of a convention NPB/Alq3-based bottom-emitting OLED. [Copyright &y& Elsevier]

Two new poly(phenylenevinylene) (PPV) oligomers, 2,2′-(1,4-phenylenedivinylene)bis-8-acetoxy quinolines were synthesized via a Knoevenagel condensation reaction. The single-crystal X-ray diffraction study shows that there are intermolecular π⋯π interactions in the solid state of 2,2′-(1,4-phenylenedivinylene)bis-8-acetoxyquinoline. Electroluminescent properties using these compounds as emitters have been investigated. [Copyright &y& Elsevier]

Mesoproterozoic (ca. 1.3 Ga) magmatism in the North China Craton (NCC) was dominated by mafic intrusions (dolerite sills) with lesser amounts of granitic magmatism, but our lack of knowledge of this magmatism hinders our understanding of the evolution of the NCC during this period. This study investigated porphyritic granites from the Huade–Kangbao area on the northern margin of the NCC. Zircon dating indicates the porphyritic granites were intruded during the Mesoproterozoic between 1285.4 ± 2.6 and 1278.6 ± 6.1 Ma. The granites have high silica contents (SiO2 = 63.10–73.73 wt.%), exhibit alkali enrichment (total alkalis = 7.71–8.79 wt.%), are peraluminous, and can be classified as weakly peraluminous A2-type granites. The granites have negative Eu anomalies (δEu = 0.14–0.44), enrichments in large-ion lithophile elements (LILEs; e.g., K, Rb, Th, and U), and depletions in high-field-strength elements (HFSEs; e.g., Nb, Ta, and Ti). εHf(t) values range from –6.43 to +2.41, with tDM2 ages of 1905–2462 Ma, suggesting the magmas were derived by partial melting of ancient crustal material. The geochronological and geochemical data, and regional geological features, indicate the Mesoproterozoic porphyritic granites from the northern margin of the NCC formed in an intraplate tectonic setting during continental extension and rifting, which represents the response of the NCC to the break-up of the Columbia supercontinent. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs), a new type of porous functional material, have attracted widespread attention in the field of adsorption separation, medicine, and catalysis, etc., due to their unique adjustable pore structure and large specific surface. The defective zirconium-based MOF is rich in terminal Zr–OH induced by the lack of linkers and the μ3-OH originating from the Zr cluster, exhibiting high affinity for the carboxyl and sulfonic acid groups in the dyes. We report the performance of two defective zirconium-based MOFs (MOF-808 and MIL-140C) to remove Eosin y (EY), Methyl orange (MO), and Orange g from the water. Owing to the strong affinity, larger specific surface area, and better-matched pore structure, MOF-808 exhibits higher adsorption capacity for EY and MO, with maximum adsorption capacities of 661.7 mg g−1 and 532.4 mg g−1, respectively. The adsorption kinetics, thermodynamics, adsorption cycle performance, and adsorption mechanism of two MOFs for three dyes were investigated. Adsorption thermodynamics and XPS analysis certified that both chemical adsorption and physical adsorption occur during the adsorption process, especially chemical adsorption. Desorption and regeneration tests demonstrate that both MOF-808 and MIL-140C maintained their high adsorption capacity after four cycles, indicating two MOFs are favorable candidates for removing pollutants. In this article, the adsorption performance of MOF-808 and MIL-140C on three different sizes and structures of anionic dyes is mainly studied. The results show that MOF-808 has better adsorption performance for EY and MO. At the same time, the adsorption results show that the chemical adsorption between the adsorbate and the MOFs material plays a leading role in the adsorption, resulting in a high adsorption capacity for EY, although the EY molecule has a larger molecular size. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the prevalence of erectile dysfunction (ED) in living donors before and after nephrectomy in China. Methods: From January 2006 to December 2008, erectile function of 94 living donors was evaluated before and after nephrectomy by International Index of Erectile Function, version 5 (IIEF-5). A subanalysis was performed by splitting the total cohort into 2 age groups: those <40 years of age (group 1, n = 21) and those ≥40 years of age (group 2, n = 73). Results: Before and after nephrectomy, the prevalence of ED in group 1 was 9.5% and 19.0% respectively, and in group 2 was 38.4% and 56.2%. The difference between groups was statistically significant at the stage of preoperation (9.5% vs 38.4%, P = .012) and 12 months postoperation (19.0% vs 56.2% P = .003). Compared with the stage of preoperation, the prevalence of ED at the stage of postoperation was significantly increased at group 2 (38.4% vs 56.2%, P = .031), but not in group 1 (9.5% vs 19.0%, P = .663). Conclusions: The prevalence of ED increased in living donors aged more than 40 years after nephrectomy in China. The change in sexual function of these living donors after nephrectomy should cause clinicians'' attention. [Copyright &y& Elsevier]

The authors report enhanced poly(3-hexylthiophene) (P3HT):methanofullerene (PCBM) bulk-heterojunction photovoltaic cells via 1,2-dichlorobenzene (DCB) vapor treatment and thermal annealing. DCB vapor treatment can induce P3HT self-organizing into ordered structure leading to enhanced absorption and high hole mobility. Further annealing the device at a high temperature, PCBM molecules begin to diffuse into aggregates and together with the ordered P3HT phase form bicontinuous pathways in the entire layer for efficient charge separation and transport. Compared to the control device that is merely annealed, optical absorption, short-circuit current, and power conversion efficiency are increased for the DCB vapor-treated cell. [ABSTRACT FROM AUTHOR]

[Display omitted] • 1. A novel SO 2 fluorescent probe B3 was synthesized. • 2. B3 can respond to SO 2 within 9 s. • 3. A high-throughput method for detecting SO 2 in food was established. • 4. B3 successfully applied to detection of SO 2 in food. Sulfur dioxide (SO 2), widely used as an antioxidant and preservative in food production, has been associated with detrimental cardiovascular and neurological effects when consumed excessively. This highlights the pressing need to develop a fast and sensitive probe capable of high-throughput screening for the quantitative determination of SO 2 in food. Herein, we synthesized a new fluorescent probe, namely B3 , specifically designed for high-throughput detection of SO 2 in food. The vinyl chloride aldehyde within the B3 structure engages in a nucleophilic addition reaction with SO 2 , contributing to B3 ′s exceptional selectivity for SO 2 , and fast response time within 9 s. Furthermore, by integrating B3 with a microplate reader, we effectively achieved high-throughput detection of SO 2 concentration up to 45 μM within a pH range of 5.5 to 8.0 in real food samples. This accomplishment serves as a significant contribution to ensuring consumer safety and facilitating health assessments. [ABSTRACT FROM AUTHOR]

Although sensitizing traditional fluorescent dyes with thermally activated delayed fluorescence (TADF) exciplexes has been extensively studied, the device performance of solution‐processed organic light‐emitting diodes (OLEDs) still lags far behind in this regard. Herein, the novel exciplex with high up‐conversion efficiency composed of a triazatruxene‐based donor and a triazine‐based acceptor is employed as a TADF sensitizer to fluorescent dye in solution‐processed hyperfluorescent OLEDs. Benefiting from the small activation energy for triplet up‐conversion and less non‐radiative recombination of triplet excitons, the new TADF exciplex can up‐convert efficiently non‐radiative triplet excitons through reverse intersystem crossing. Besides, expeditious up‐conversion processes also shorten the residence time of triplet excitons, giving rise to significant suppression of detrimental Dexter energy transfer from the exciplex sensitizer to the dopant. By maximizing the triplet up‐conversion efficiency of exciplex sensitizers, the optimized OLEDs achieve a maximum external quantum efficiency (EQEmax) of 16.0%, which is the first report for the solution‐processed exciplex‐sensitized hyperfluorescent OLEDs with EQEmax exceeding 15%. These results validate that the up‐conversion efficiency of triplet excitons in the exciplexes strongly affects the performance of exciplex‐sensitized fluorescent devices, and the triazatruxene‐based molecules are promising donor candidates for constructing the exciplexes with high up‐conversion efficiency. [ABSTRACT FROM AUTHOR]

Phosphorescent manganese(II) complexes with high photoluminescence quantum yields (PLQYs) and low cost exhibit great potential in organic light‐emitting diodes (OLEDs), information security, and X‐ray imaging. However, it is still a challenge to tune their emission colors. Herein, an effective strategy for engineering the phosphorescence colors of tetrahedral Mn(II) complexes through steric hindrance‐driven bond angle distortion is proposed. Modulating the steric hindrance between phosphine and benzofuran and varying the O─Mn─O bond angles allows these Mn(II) complexes to emit from 498 to 548 nm. Interestingly, these achiral single crystals of Mn(II) complexes exhibit significant circularly polarized luminescence signals due to symmetry breaking. Furthermore, high‐performance green OLEDs are achieved by using these Mn(II) complexes as dopants, providing a record‐high external quantum efficiency of 15.7%. These super‐duper results greatly inspire the development of multi‐color Mn(II) complexes and low‐cost Mn‐based devices. [ABSTRACT FROM AUTHOR]

As a significant paradigm change in reinforcement learning, federated learning (FL) has emerged to address the efficiency bottlenecks and privacy concerns of centralized training. However, the discrepancy of multi-energy demands among energy hubs (EHs) may cause undesirable instability of FL mechanisms. This study proposes a scheduling algorithm for adaptively controlling multiple EHs with combined heat and power, gas boiler, and electrical boiler. We first present the formulations of twin delayed deep deterministic policy gradient (TD3) to schedule the energy conversion under the time-varying price and demands of electricity, heat, and natural gas. The novelty of the proposed algorithm lies in developing a distributed TD3-agents training that consists of FL and matching-based agent-to-agent learning, namely matching learning (ML). Specifically, the FL is first introduced for collaborative training of EH's TD3 agents by sharing their semi-trained scheduling models. The ML innovatively proposed for addressing the training instability of FL is formulated as a matching game in which the poor-trained agents learn the scheduling knowledge from the agent who has analogous demand patterns and better reward. Simulation results display the advantage and feasibility of the proposed algorithm in terms of the speed of training convergence, energy consumption of equipment, and economic benefit. • An adaptive scheduling model for the energy hub using the DRL algorithm is established. • Federated deep reinforcement learning is employed to cope with the requirement of data-privacy preserving. • Matching learning is proposed to improve the convergence speed of DRL agents by offsetting the training instability of large-scale sharing learning. • The proposed algorithm can achieve remarkable training efficiency and economic benefit for multiple energy hubs. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) play a crucial role in regulating various physiological processes, including cell differentiation, proliferation, and apoptosis. However, their specific functions in response to heat stress are not fully understood. This study aimed to investigate the regulatory effects of miR-199a-3p on the proliferation of heat stress-treated spermatogonial stem cells (SSCs). SSCs were isolated from mouse testes and cultured in vitro to identify marker molecules. Lentiviruses carrying miR-199a-3p-over, miR-199a-3p-inhibit, and ID4 -over constructs were generated for stable transfection. Luciferase assay was employed to confirm the targeting relationship between miR-199a-3p and ID4. An in vitro SSCs heat stress model was established, and the miR-199a-3p-inhibit and ID4 -over groups were included. Cellular proliferation was assessed using CCK-8, EdU, and cell cycle analysis methods after heat stress. Expression levels of miR-199a-3p and ID4 were evaluated by western blotting and qRT-PCR. The results demonstrated that miR-199a-3p-over inhibited SSCs proliferation, while ID4 -over promoted an increase in SSCs number. Luciferase assay confirmed the regulatory effect of miR-199a-3p on ID4 expression. Moreover, after heat stress treatment, miR-199a-3p-inhibit and ID4 -over enhanced SSCs proliferation compared to the control group. These findings suggest that miR-199a-3p modulates SSCs proliferation by targeting ID4 , especially under heat stress conditions. • Compared with the control group, heat stress inhibited the self-renewal of spermatogonial stem cells. • When subjected to heat stress, miR-199a-3p affects the proliferation of spermatogonial stem cells. • Spermatogonial stem cells are essential for male fertility. [ABSTRACT FROM AUTHOR]

Abstract In this paper, R23, R41 and R170 are used in the low-temperature cycle (LTC) and R32, R1234yf, R1234ze, R161, R1270, R290 and R717 are used in the high-temperature cycle (HTC) refrigerant in cascade refrigeration system (CRS). In order to evaluate the potential of refrigerant and find out which refrigerant couple performs better in CRS, energy and exergy analysis were conducted to investigate the effect of operation parameters. The results show that R161 is recommended for use in HTC, and R41 and R170 are recommended for use in LTC. In the 28 refrigerant groups studied, R41/R161 and R170/R161 are recommended used in CRS and the use of R41/R161 in CRS is superior to other refrigerants in improving COP and thermodynamic performance when the evaporation temperature is about higher than −60 °C. The largest exergy destruction component is condenser. Therefore, the future optimization work can be carried out on the condenser. The results provide a theoretical basis for the selection of low-GWP refrigerant couples in CRS. Highlights • The potential of R23, R41 and R170 with low GWP refrigerants in cascade refrigeration system has been studied. • R161 is recommended for use in HTC, and R41 and R170 are recommended for use in LTC. • The refrigerant couples of R41/R161 and R41/R717 are recommended used in CRS. [ABSTRACT FROM AUTHOR]

Quasi‐2D perovskites are promising emitters in light‐emitting diodes (LEDs) due to their natural quantum well (QW) structure and tunable exciton binding energy. Synergistic regulation of the defect passivation and QW width distribution of quasi‐2D perovskites is crucial to achieve high‐performance perovskite‐based LEDs. Herein, a combination of two additives, i.e., 3‐(diaminomethylidene)‐1,1‐dimethylguanidine (Metformin) and 1,4,7,10,13,16‐hexaoxacyclooctadecane (Crown) having preferential interactions with different quasi‐2D perovskite precursors is proposed to synergistically passivate the defects and regulate the QW width distribution of quasi‐2D perovskites. Metformin additive interacts strongly with lead bromide, mainly passivating the defects. Crown additive has preferential interactions with organic spacer phenethylammonium bromide, which dominates the QW width distribution and induces quasi‐2D perovskites with uniform dimensions. The dual additives of Metformin and Crown interact preferentially with distinct precursors, allowing to regulate the QW width distribution and defect density of quasi‐2D perovskites synergistically. A photoluminescence quantum yield as high as 91.5% is achieved for the quasi‐2D perovskite prepared with the dual‐additive strategy. Moreover, high‐efficiency quasi‐2D perovskite LEDs were successfully fabricated with a maximum external quantum efficiency of 21.3% and a maximum luminance over 30 000 cd m−2. This work provides a preferential interaction‐guided dual‐additive strategy to fabricate high‐efficiency quasi‐2D perovskite LEDs without anti‐solvent treatment. [ABSTRACT FROM AUTHOR]

Jurassic terrestrial sediments of the Jianggalesayi–Washixia Basin in the northwestern Altyn Tagh Orogen record abundant information regarding the evolution and uplift of the orogen. Investigation of this orogen is critical to establishing whether the Tarim and Qaidam basins were connected during the Jurassic. In this study, we present 474 single‐grain laser‐ablation–inductively coupled plasma–mass spectrometry detrital zircon U–Pb ages obtained from five Jurassic sandstone samples collected from four sections in the basin. Detrital zircons from the Lower Jurassic strata yield age populations of 997–726 and 551–509 Ma, indicating that the zircons were derived mainly from the southern–central Central Altyn Tagh Massif. Zircon age populations from the lower Middle Jurassic strata are 1024–838, 778–643, and 543–357 Ma, which suggest that the sediments were derived predominantly from the northern Central Altyn Tagh Massif and the southern South Altyn Tagh subduction–collision complex belt (SATSB). Zircon age populations from the upper Middle Jurassic strata are 980–830, 556–424, and 277–245, suggesting that these sediments were derived from the central SATSB. Detrital zircons from the Upper Jurassic strata display age groups of 515–387 and 325–226 Ma, indicating that these sediments originated from the northern SATSB. Uplift of the Altyn Tagh Orogen was initiated during the Middle to Late Triassic as a synchronous far‐field response to the collision of the Qiangtang Block with the Eurasian Plate. By the Early Jurassic, the Qaidam Basin was no longer connected with the Tarim Basin. During the Late Jurassic to Early Cretaceous, the collision of the Lhasa Block with the southern margin of the Eurasia Plate led to further uplift of the Altyn Tagh Orogen. [ABSTRACT FROM AUTHOR]

The fourth paradigm of science has achieved great success in material discovery and it highlights the sharing and interoperability of data. However, most material data are scattered among various research institutions, and a big data transmission will consume significant bandwidth and tremendous time. At the meanwhile, some data owners prefer to protect the data and keep their initiative in the cooperation. This dilemma gradually leads to the "data island" problem, especially in material science. To attack the problem and make full use of the material data, we propose a new strategy of neural network training based on multi-source databases. In the whole training process, only model parameters are exchanged and no any external access or connection to the local databases. We demonstrate its validity by training a model characterizing material structure and its corresponding formation energy, based on two and four local databases, respectively. The results show that the obtained model accuracy trained by this method is almost the same to that obtained from a single database combining all the local ones. Moreover, different communication frequencies between the client and server are also studied to improve the model training efficiency, and an optimal frequency is recommended. [ABSTRACT FROM AUTHOR]

We demonstrate that polymer electron acceptors with excellent all-polymer solar-cell (all-PSC) device performance can be developed from polymer electron donors by using B←N units. By alleviating the steric hindrance effect of the bulky pendant moieties on the conjugated polymers that contain B←N units, the π-π stacking distance of polymer backbones is decreased and the electron mobility is consequently enhanced by nearly two orders of magnitude. As a result, the power conversion efficiency of all-PSCs with the polymer acting as the electron acceptor is greatly improved from 0.12 % to 5.04 %. This PCE value is comparable to that of the best all-PSCs with state-of-the-art polymer acceptors. [ABSTRACT FROM AUTHOR]

We demonstrate that polymer electron acceptors with excellent all-polymer solar-cell (all-PSC) device performance can be developed from polymer electron donors by using B←N units. By alleviating the steric hindrance effect of the bulky pendant moieties on the conjugated polymers that contain B←N units, the π-π stacking distance of polymer backbones is decreased and the electron mobility is consequently enhanced by nearly two orders of magnitude. As a result, the power conversion efficiency of all-PSCs with the polymer acting as the electron acceptor is greatly improved from 0.12 % to 5.04 %. This PCE value is comparable to that of the best all-PSCs with state-of-the-art polymer acceptors. [ABSTRACT FROM AUTHOR]

An attempt was made to analyze the damage evolution and ductile fracture of incremental forming at the microscopic level. Firstly, an extended Gurson-Tvergaard-Needleman (GTN) model integrating with Hill'48 anisotropic yield criterion was established and numerically implemented by User-defined Material Subroutine (VUMAT) in the commercial finite element software ABAQUS. Then, the VUMAT program was verified via a single element test, and its damage parameters were determined through the combination of the simulation and the experiment of a tensile test. Afterwards, based on the extended GTN model, a finite element model of incremental forming was established and experimentally verified. And the influence of different values of two damage parameters, the volume fraction of void nucleating particles f and the mean plastic strain value when voids nucleate ε, on the damage evolution of incremental forming was explored. It shows that there is almost no connection between the microscopic equivalent strain $$ {\overline{\varepsilon}}_{\mathrm{m}}^{\mathrm{pl}} $$ and the values of f and ε. However, the maximum value of void volume fraction will increase significantly with the increase of f or with the decrease of ε. Finally, void volume fraction was proved to be an effective index to predict crack occurrence of incremental forming. [ABSTRACT FROM AUTHOR]

• A multiple-loss absorbers hybrids of Co@MWCNTs with 3D structure. • The density of cobalt microspheres were reduced by electroless plating. • The flower-like cobalt microspheres were prepared while the pH value was 12. Chemical plating as a simple and effective method has been widely used in the production of metal materials, which can essential to reduce the density and improve the application of metal materials. In this paper, the cobalt microspheres were prepared by chemical plating while the polystyrene-microspheres were as a template. It was found that the pH value of reaction had a significant impact on the microtopography of Co-microsphere. XRD results of the Co-microsphere illustrated that, the crystal shape of Co-microspheres were affect by the pH value. Otherwise, the SEM results indicated that the flower-like cobalt microspheres were prepared while the pH value was 12. In addition, the microtopography of Co-microsphere had a significant effect on microwave absorption property of Co@MWCNTs. The reflection loss results demonstrated that, the Co-12@MWCNTs had a good microwave absorption performance, while the maximum reflection loss was −38.94 dB and the effective absorbing bandwidth was 4.28 GHz at a thickness of 2 mm. Therefore, it is necessary to study the influence of pH value on the microtopography of Co-microspheres and microwave absorbing mechanism of Co@MWCNTs. [ABSTRACT FROM AUTHOR]

Two D‐A copolymers consisting of fused ring pyrrolo‐dithieno‐quinoxaline acceptors are synthesized with different donor units, i.e., benzodithiophene (BDT) with alkylthienyl (P134) and 2‐ethylhexyloxy (P117) side chains. These copolymers are used as donors and a narrow bandgap acceptor Y6 to fabricate bulk heterojunction polymer solar cell devices. Owing to the strong electron‐deficient fused ring pyrrolo‐bithieno‐quinoxaline and weak alkyl thienyl side chains in BDT, the polymer solar cells (PSCs) based on P134:Y6 attain the power conversion efficiency (PCE) of 15.42%, which is higher than the P117:Y6 counterpart (12.14%). The superior value of PCE for P134:Y6 can be associated with more well‐adjusted charge transport, weak charge recombination, proficient exciton generation, and dissociation into free charge carriers and their subsequent charge collection owing to the dense π–π stacking distance and more considerable crystal coherence length for the P134:Y6 thin films. This investigation confirms the great potential of a strong acceptor‐weak donor tactic for developing efficient D‐A copolymers consists of quinoxaline acceptor for PSCs. [ABSTRACT FROM AUTHOR]

A novel absorbing material with a flexible sandwich structure (S121) was designed and assembled using light-weight foams of Polydimethylsiloxane (PDMS) to achieve a full X-band absorption. The PDMS foams based on the composites of hollow polyaniline and MWCNTs (HPC) were prepared by means of impregnation technology selecting sugar cubes as a template. For the construction of sandwich S121, the upper and lower layers were HPC-PDMS foams (d foam = 1.0 mm) and the middle layer was HPC-PDMS film (d film = 0.5 mm). The SEM results revealed plentiful pores existed in S121, which would endow S121 with the traits of light-weight and lower density. The absorption performance of S121, single-layer HPC-PDMS foam (S1) and single-layer HPC-PDMS film (S2) had been characterized. Of importance, S121 achieved full absorption in X-band and its minimum reflection loss (RL min) reached −32.65 dB at 9.5 GHz. In contrast, the RL min of S1 and S2 were only −15.42 dB and −11.72 dB. The frequency regions with RL < −10 dB of S1 and S2 were surprisingly narrow, which were 1.5 GHz and 0.4 GHz, respectively. The results indicated that the design of S121 demonstrated a synergistic effect of foams and film, which was helpful to enhance absorption and realize an X-band full absorption. Of great significance, due to the excellent flexibility of S121, after bending and compressing many times, RL min value is nearly identical to that of original S121, and the effective bandwidth is also full coverage of X-band. The results showed that the proposed S121 design is feasible for applications in X-band. [Display omitted] • A flexible sandwich was designed and assembled based on PDMS foam and film. • The sandwich was constructed by filtering, absorbing and reverse interference layers. • The sandwich achieved a full X-band absorption and the RL min of −32.65 dB at 9.5 GHz. • The sandwich still kept admirable EM absorption after bending and compressing tests. [ABSTRACT FROM AUTHOR]

A new acceptor unit anthra[1,2‐b: 4,3‐b': 6,7‐c'']trithiophene‐8,12‐dione (А3Т) (A2) is synthesized and used to design D‐A1‐D‐A2 medium bandgap donor copolymers with same thiophene (D) and A2 units but different A1, i.e., fluorinated benzothiadiazole (F‐BTz) and benzothiadiazole (BTz) denoted as P130 and P131, respectively. Their detailed optical and electrochemical properties are examined. The copolymers show good solubility in common organic solvents, broad absorption in the visible spectral region from 300 to 700 nm, and deeper HOMO levels of −5.45 and −5.34 eV for P130 and P131, respectively. Finally, an optimized polymer solar cell (PSC) based on P131 as the donor and narrow bandgap non‐fullerene small molecule acceptor Y6 demonstrated a power conversion efficiency (PCE) of >11.13%. To further improve the efficiency of the non‐fullerene PSC, the P130 is optimized by introducing a fluorine atom into the BTz unit, F‐BTz acceptor unit, and PCE PSC based on P130: Y6 active layer increased to >15.28%, which is higher than that for the non‐fluorinated analog P131:Y6. The increase in the PCE for former PSC is attributed to the more crystalline nature and compact π–π stacking distance, leading to more balanced charge transport and reduced charge recombination. These remarkable results demonstrate that A3T‐based copolymer P130 with F‐BTz as the second acceptor is a promising donor material for high‐performance PSCs. [ABSTRACT FROM AUTHOR]

Solution-processed white organic light-emitting diodes (WOLEDs) have drawn great attention both in the academic and industrial research communities due to the potential application in low-cost, large-area, solid-state lightings. Issues related to the device efficiencies are largely hampering progress in this field. Alongside the development of new materials and novel device architectures, distinct progress has been made for such white devices. In particular, the all-phosphorescent light-emitting strategy has been intensively developed in recent years, mainly focusing on a hostguest, doping-system-based, single-active-layer structure and a solution-processed, multilayer device structure. Novel approaches, including white single polymers and excimer-/exciplex-based white devices, have also appeared as a promising choice and received great attention. As a prerequisite, the issue of the morphology of the emissive layer is also important and has an influence on the optoelectronic behavior of the device. Herein, major advances in solution-processed WOLEDs based on polymers, dendrimers, or solution-processed small molecules are summarized. Special attention is focused on the main progress in high-efficiency, solution-processed WOLEDs with the key strategies mentioned above and the morphology issue in these systems. The remaining challenges in pursuing the development of reliable and energy-saving lighting devices are also discussed. [ABSTRACT FROM AUTHOR]

Solution processable transparent top electrodes with good conductivity and high transmittance play a critical role in developing highly efficient semitransparent organic solar cells (ST-OSCs). Herein, a simple low-temperature spray-coating method is proposed to fabricate silver nanowires/zinc oxide nanoparticles (AgNWs/ZnO) composite electrodes. The effects of coverage of ZnO nanoparticles on optoelectronic properties and surface morphologies of the composites are systemically investigated. Compared to the pristine AgNWs, the AgNWs/ZnO composite layer exhibits improved electrical conductivity due to the filling of nanoparticles as well as the capillary force caused during the volatilization of ZnO dispersion. A low sheet resistance of 8.3 Ω/ and a high transmittance of 78.91 % at 550 nm are achieved in the optimized AgNWs/ZnO composite films with excellent thermal and mechanical stabilities. By using the spray-coated AgNWs composite as the top electrode, the PM6:N3 based ST-OSCs prepared on ITO/glass substrate attain a power conversion efficiency (PCE) of 10.88 % and an average transmittance (AVT) of 28.80 % due to the enhanced charge extraction and suppressed trap-assisted recombination. Moreover, fully solution-processed ST-OSCs are fabricated based on AgNWs/ZnO top electrodes, achieving a PCE of 9.01 % and an AVT of 27.8 %. It provides a simple and effective strategy to fabricate transparent flexible top electrodes and may pave the way towards all-solution-processed highly efficient ST-OSCs. • A simple low-temperature spray-coating method is proposed to fabricate AgNWs/ZnO top electrodes. • The coverage of ZnO improves both conductivity and morphology of the composites. • The resultant devices show enhanced charge extraction and suppressed recombination. • All-solution-processed flexible ST-OSCs achieve a PCE of 9.0 % and AVT of 27.8 %. [ABSTRACT FROM AUTHOR]

Excessive organic ligands damage the crystallinity of blue quasi‐2D perovskite, resulting in a small‐grain film with a high grain boundary ratio. Herein, oriented blue perovskite nanoplates are fabricated by using antisolvent additive engineering to tackle this issue. The introduction of triphenylphosphine oxide additive in antisolvents significantly increases the perovskite grain sizes, laying the foundation for in situ formation of perovskite nanoplates. The miscibility between ethyl acetate antisolvent and dimethyl sulfoxide host solvent affects formation of the oriented perovskite nanoplates. The perovskite film containing oriented nanoplates with enhanced crystallinity exhibits elevated photoluminescence quantum yield as compared to the control samples. Based on the oriented perovskite nanoplates, blue perovskite light‐emitting diodes (PeLEDs) with an emission peak at 488 nm and a maximum external quantum efficiency of 9.5% are successfully fabricated. Moreover, the blue PeLEDs deliver a high brightness of 4256 cd m–2 with stable electroluminescent spectra. [ABSTRACT FROM AUTHOR]

Abstract: We investigate the electroluminescent performance of single-layer polymer light-emitting diodes with the emissive layer comprised of poly(N-vinyl carbazole) (PVK): electron-transporting molecules (ETMs):iridium(III) [bis(4,6-difluorophenyl)-pyridinato-N,C2]-picolinate (FIrpic) trinary components. A series of ETMs with comparable energy levels is tentatively utilized to modulate the morphology. The morphology of the emissive layer is studied using the transmission electron microscopy and atomic force microscopy in combination with the interfacial energy calculation between these components, with purpose to understand the multi-component miscibility and morphological properties of these emissive layers. It is found that the multi-component miscibility has dramatic influence on the morphology of the multi-component emissive layer and the final electroluminescent performance of the devices. The results reveal that the aggregation of ETMs mainly results in an increase of driving voltages, while the aggregation of FIrpic emitters would lead to the reduction in the luminous efficiencies as a result of their self-quenching effects. The PVK:1,3-bis[(p-tert-butyl)phenyl-1,3,4-oxadiazoyl]benzene (OXD-7): FIrpic blend demonstrates a more uniform morphology resulting in an optimal luminous efficiency of 15cdA−1. [Copyright &y& Elsevier]

Abstract: A new donor-acceptor polymer (PDTPDBF), containing both dithieno[3,2-b:2′,3′-d]pyrrole (DTP) and fluorene as electron-donating units and benzo-2,1,3-thiadiazole (BT) as electron-accepting unit, was synthesized by Suzuki coupling reaction. Its optical, thermal, electrochemical and photovoltaic properties have been investigated. Compared with typical DTP-based donor-acceptor polymers, PDTPDBF showed a distinct low HOMO level (−5.47 eV). Theoretical calculation attributed this low-lying HOMO level to both the weaker electron-donating ability of the fluorene unit and the moderately twisted conformation between the fluorene unit and the BT unit. Polymer solar cells (PSCs) based on PDTPDBF and PC71BM (1:2, w/w) exhibited an open circuit voltage of 0.84 V and a power conversion efficiency (PCE) of 4.2%, both of which are relatively high values for DTP-based photovoltaic polymers. [Copyright &y& Elsevier]

Abstract: Cross-linkable polycarbazole copolymers have been synthesized starting from 3,6-diiodo-9-(2-ethylhexyl)carbazole and 3,6-diodo-9-[6-(3-ethyloxetan-3-ylmethoxy)hexyl]carbazole monomers in a Ni(0)-catalyzed Yamamoto-type aryl–aryl coupling. The synthesized materials were characterized by various techniques including differential scanning calorimetry, thermogravimetry and cyclic voltammetry. Insoluble layers of the copolymers have been obtained by photo-crosslinking thin films of the materials. Organic light emitting diodes using the crosslinked polycarbazole networks as hole transporting layer demonstrated a turn-on voltage of ca. 4V, a maximum brightness of 15,000cd/m2, and maximum OLED efficiency of 8.5cd/A. [Copyright &y& Elsevier]

Abstract: A new 3,6-dithien-2-yl-2,5-dialkylpyrrolo[3,4-c]pyrrole-1,4-dione (DTDPP) based polymer, poly{thieno[3,2-b]thiophene-alt-3,6-dithien-2-yl-2,5-di(2-octyldodecyl)-pyrrolo[3,4-c]pyrrole-1,4-dione} (PTT-DTDPP) was synthesized by the Stille coupling reaction. The polymer shows a broad absorption in visible and near infrared region and displays suitable HOMO/LUMO energy levels for marching with those of PCBM acceptor. The photovoltaic properties of the polymer were studied by bulk heterojunction solar cell devices using PTT-DTDPP as donor and PC71BM as acceptor. The power conversion efficiency of device achieved 1.60% under the illumination of AM1.5G, 100mW/cm2. [Copyright &y& Elsevier]

Abstract: New donor/acceptor polymers PBDTTPT1 and PBDTTPT2 with alternating benzodithiophene (BDT) and bisthiophene-dioxopyrrolothiophene (TPT) units were synthesized by Stille coupling reaction. The polymers had optical bandgaps of 1.78 and 1.82 eV, and HOMO energy levels of −5.30 and −5.35 eV for PBDTTPT1 and PBDTTPT2, respectively. Polymeric solar cell devices based on these copolymers as donors and PC71BM as acceptor showed the highest open circuit voltage of 0.95 V and power conversion efficiency of 2.68% under the illumination of AM 1.5, 100 mW/cm2. [ABSTRACT FROM AUTHOR]

Abstract: We present the results of a systematic study on how the solvent processing affects the EL properties of a single emissive layer white PLED based on a polyfluorene derivative polymer. The EL spectrum of the device using solvent processing, peaked at 436, 572nm, shows a pure white emission and the luminous efficiency is enhanced, which is attributed to the presence of the crystalline polyfluorene induced by solvent processing. The crystalline polyfluorene that acts as the self-dopant enhances the blue emission and increases the purity of the white light. Most importantly, the charge transport is balanced after solvent processing, which favors improving the luminous efficiency. A light-emitting efficiency of 12cd/A is achieved after solvent processing, about 50% increase compared to the as-spincoated device. [Copyright &y& Elsevier]

Abstract: The rational design, synthesis and characterization of five phosphorescent platinum complexes [(C^N)Pt(acac)] [Hacac=acetylacetone, HC^N=1-methyl-2-(4-fluorophenyl)benzoimidazole (H-FMBI), 1-methyl-2-phenylbenzoimidazole (H-MBI), 1,2-diphenyl-benzoimidazole (H-PBI), 1-(4-(3,6-di-t-butylcarbazol-9-yl))phenyl-2-phenylbenzoimidazole (t-BuCz-H-PBI), and 1-(4-(3,6-di-(3,6-di-t-butyl-carbazol-9-yl))carbazol-9-yl)phenyl-2-phenylbenzoimidazole (t-BuCzCz-H-PBI)] have been discussed. The crystal structure of (MBI)Pt(acac) shows a nearly ideal square planar geometry around Pt atom and the weak intermolecular interactions with π–π spacing of 3.55Å. All of the complexes emit green phosphorescence from the metal-to-ligand charge-transfer (MLCT) excited state with high quantum efficiency (0.08–0.17) at room temperature. A multilayer organic light-emitting diode (OLED) with (MBI)Pt(acac) as phosphorescent dopant was fabricated using the method of high-vacuum thermal evaporation, which gives a maximum brightness, luminous and power efficiency of 13605cd/m2, 15.1cd/A and 4.3lm/W, respectively. In contrast, the comparable performance can be achieved in the solution-processed OLED based on (t-BuCzPBI)Pt(acac) with a peak brightness, luminous and power efficiency of 13606cd/m2, 17.5cd/A and 8.4lm/W, respectively. The better device efficiency results from the good square plane of central Pt coordination unit and the inhibition of the aggregates due to bulky and rigid t-butylcarbazole dendrons. [Copyright &y& Elsevier]

Abstract: We developed an approach to realize blue, green and red emission from top-emitting white organic light-emitting diodes (OLEDs) through depositing exterior tunable optical films on top of the OLEDs. Three primary colors for full color display including blue, green and red emission are achieved by controlling the wavelength-dependent transmittance of the multilayer optical films overlaid on the emissive layer. The advantage of such a device configuration is that the emissive color of the OLEDs can be tuned via the exterior optical films which do not affect the electrical characteristics of the device. This may provide a way to realize full color display by using white top-emitting OLEDs. [Copyright &y& Elsevier]

A novel series of emitting aluminum complexes containing two 8-hydroxyquinoline ligands (q) and a phenolato ligand (p) were synthesized and characterized. Double layer organic light-emitting diodes (OLEDs) were fabricated using these complexes as luminescent layers, and strong electroluminescence (EL) was observed. It was found that their emitting wavelengths were mainly determined by the first ligands (q). Cyclic voltammograms revealed a partially irreversible n-doping process and indicated that these complexes show excellent electron-transporting ability. [Copyright &y& Elsevier]