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A more accurate and efficient millimeter-wave imaging algorithm for a monostatic system is presented in this paper. Firstly, a more precise physical model is implemented, which considers the propagation loss of both the incident wave and scattered wave. However, this physical model cannot be processed using classical mathematical methods such as spherical wave decomposition and Weyl identity. Instead, the method of stationary phase (MSP) is applied to derive the imaging formula. As a result, the proposed algorithm achieves superior imaging results for multiple targets at different ranges. Additionally, the range stacking technique is introduced to avoid time-consuming interpolation, which also contributes to improving computational efficiency comparing to the algorithms employing interpolation. The simulation results show that the proposed algorithm reduces the computation time by half. The proposed algorithm has been further verified through real data collected with our in-house developed prototype. [ABSTRACT FROM AUTHOR]

The complete regeneration of deer antlers is based on the proliferation and differentiation of stem cells. Mesenchymal stem cells (MSCs) of antlers have an important role in antler regeneration and rapid growth and development. HGF is mainly synthesized and secreted by mesenchymal cells. After binding to its receptor c-Met, which transduces signals into cells to stimulate cell proliferation and migration in various organs to promote tissue morphogenesis and angiogenesis. However, the role and mechanism of the HGF/c-Met signaling pathway on antler MSCs are still unclear. In this study, we established antler MSCs with overexpression and interference of HGF gene by lentivirus and small interference RNA, observed the effect of HGF/c-Met signal pathway on the proliferation and migration of antler MSCs, and detected the expression of downstream related signal pathway genes, to explore the mechanism of HGF/c-MET signal pathway on the proliferation and migration of antler MSCs. The results showed that the HGF/c-Met signal affects the expression of RAS, ERK and MEK genes, regulates the proliferation of pilose antler MSCs through Ras/Raf, MEK/ERK pathway, affects the expression of Gab1, Grb2, AKT and PI3K genes, and regulates the migration of MSCs of pilose antler through Gab1/Grb2 and PI3K/AKT pathway. [ABSTRACT FROM AUTHOR]

Biological vision mechanism plays a very important role in detecting object contour information, so the research of bio-inspired contour detection has attracted widespread attention. In the visual physiological mechanism of contour detection, complex cells in the primary visual cortex (V1) receive the target edges output by simple cells, and subsequently aggregate and integrate the edges into contours. Inspired by the receptive field properties of complex cells in the V1 area, we design a contour detection network with an encoder-decoder structure, called the clustered suppression network. In the encoding network, we propose a feature aggregation encoding framework inspired by the clustered distribution properties of complex cells. At the same time, based on the inhibition mechanism properties of the non-classical receptive field of complex cells and the response properties to motion edges, we propose a suppression module and a spatial motion detection module, which are integrated into the encoding network. In the decoding network, we propose a highly aggregated decoding network inspired by the horizontal connection properties of complex cells. Choosing the BSDS500 natural scene dataset as the experimental object, the F-score is selected as the evaluation index. The average optimal F-score on a single-scale of the proposed method is 0.802. Concurrently, the NYUD-v2 dataset and BIPED dataset are used for further verification and achieved good results. The codes are available at https://github.com/smallsunq/CSNet-Contour-detection. [ABSTRACT FROM AUTHOR]

Projection adjustment is a technique that improves the rate of convergence, as measured by the number of iterations needed to achieve a given level of performance, of the Kaczmarz algorithm (KA) for iteratively solving a system of consistent linear equations, however at the cost of requiring additional time per iteration and increased storage. This hinders the applicability of the previously published Kaczmarz algorithm with projection adjustment (KAPA) to large-scale problems. An enhancement EKAPA of KAPA that uses projection adjustment only for a small subset of the equations is proposed for significantly reducing the time and storage requirements. An analysis of the behavior of EKAPA is provided. An illustration is given to show that EKAPA using a small subset of the equations for projection adjustment can achieve a speed-up over KA similar to that of KAPA in terms of the number of iterations, but requires much less computer time and storage; hence, it is more suitable for large-scale problems. [ABSTRACT FROM AUTHOR]

Recent years has seen Chinese enterprises competing to broaden the scope of business through the internationalization strategy. The proliferation of the strategy is attributable to the favorable environment created by the Chinese government with the increasingly stringent requirements on corporate social responsibility. The external pressure of social responsibility has also stimulated the fulfillment of social responsibility within the enterprises. Against this backdrop, this paper constructs a mathematical model with the constraint of external social responsibility pressure and applies the model to examine the effect of the internationalization strategy of Chinese enterprises on enterprise value. The research finds that: First, the internationalization strategy enhances the enterprise value; the stakeholders will jointly promote the strategy once they are aware of its significance. Second, with the increase in the external pressure of social responsibility, the enterprises will promote enterprise value through the implementation of social responsibility. Third, the fulfillment of corporate social responsibility contributes to the proliferation of internationalization strategy and further enhances the long-term enterprise value. These modeling conclusions are validated through an empirical test. This research enriches the exploration into the internationalization strategy of enterprises in emerging markets and pioneers the study on the fulfillment of corporate social responsibility from the external angle. [ABSTRACT FROM AUTHOR]

In this work, a two-layer depth-integrated smoothed particle hydrodynamics (SPH) model is applied to investigate the effects of landslide propagation on the impulsive waves generated when entering a water body. In order to deal with the open boundary in practical engineering problems, an absorbing boundary method, based on Riemann invariants which can be applied to arbitrary geometries, is implemented. In order to examine the accuracy of the proposed formulation, the model is tested against both available laboratory tests and numerical examples from the literature. Then, it is adopted to model the characteristics of the impulse waves generated by the Halaowo landslide in the Jinsha River, China. The results provide a technical basis for the emergency plan to the Halaowo landslide and benefit the disaster prevention policy, which helps mitigating future hazards in similar reservoir areas. [ABSTRACT FROM AUTHOR]

Edge detection is a key step in various image processing tasks. Edge detection based on deep learning is usually composed of encoding and decoding networks. Encoding networks are usually built based on classifiers (e.g., VGG16) while focusing on the construction of decoding networks. In this paper, an encoding–decoding network is proposed by simulating the visual pathway of the retina-lateral geniculate nucleus (LGN)- the primary visual cortex (V1)-V2-V4- the inferior temporal cortex. Bio-inspired Feature Cascade Network (BFCN) was designed to simulate the transmission modes of feedforward propagation, horizontal connection, and feedback propagation among neurons in the IT, which is conducive to enhancing the characteristic analysis ability of the decoding network. Firstly, to simulate the information processing model of feedforward propagation, a Feedforward Propagation Network is designed to fully fuse the underlying information. Secondly, to simulate the information processing model of the horizontal connection between neurons, the Inter-Layer Information module (ILI) is designed to process the interlayer information of FPNet, which is beneficial to enhancing the feature extraction ability. Finally, to simulate the feedback propagation, the Proximity Combination Network (PCNet) is designed to integrate the feature prediction of each stage and strengthen the generalization ability of the network. Experimental results show that the proposed contour detection model outperforms current similar models. [ABSTRACT FROM AUTHOR]

Purpose: The BCLC staging classification has been widely endorsed to predict the prognosis of patients with HCC. However, its validity as a means of therapeutic instructions needs to be challenged. This study aimed to evaluate perioperative and long-term outcomes of surgical resection in patients with advanced hepatocellular carcinoma (HCC) according to the Barcelona Clinic Liver Cancer (BCLC) staging. Methods: This study used a prospectively maintained database consisting of a consecutive series of 511 Chinese patients with advanced HCC who underwent surgical resection in a hepatobiliary surgical center from 2001 to 2007. Mortality, morbidity, long-term overall survival (OS) and disease-free survival (DFS) were evaluated. Results: Hospital mortality was 2.3%, and overall morbidity was 31.3%. After a median follow-up period of 27.8 months (range, 0-112 months), the 1-, 3- and 5-year OS rate was 69.9, 41.2 and 30.5%, and the 1-, 3- and 5-year DFS rate was 48.2, 30.3 and 24.0%, respectively. The 1-, 3- and 5-year OS and DFS rates were significantly poorer in patients with vascular invasion and/or extrahepatic spread than those in patients without (both P < 0.001), and also poorer in patients with biliary invasion than those in patients without (both P < 0.05). Conclusions: Surgical resection could be considered in part of patients with advanced HCC (BCLC stage C), with low mortality, acceptable morbidity and favorable survival benefits. These results imply that BCLC recommendations for treatment schedules of advanced HCC need to be re-evaluated. [ABSTRACT FROM AUTHOR]

To provide a comprehensive network access service to wireless users, a network operator may operate different types of wireless networks (such as GPRS, Wi-Fi, HSDPA, UMTS, WiMAX and 3GPP LTE) simultaneously to become a heterogeneous wireless network operator, such as Vodafone and T-Mobile. With convenience of accessing wireless networks, ubiquitous services would stimulate the bandwidth expenditure in the network backbone. Lots of various demanded traffic from heterogeneous access networks may converge toward Internet through the common backbone in the operator. Efficiently utilizing the common backbone can offer a better quality of service to users and maximize the revenues for the operator. To our best knowledge, few studies had ever been made in such a contemporary wireless network environment in the past. In this study, we propose solutions to efficiently allocate the bandwidth for user requests and fully utilize the unused bandwidth in the network backbone owned by the heterogeneous wireless network operator. Our simulation results show that our scheme can increase the utilization of the backbone bandwidth, shorten the request completion time for users and generate more revenue for the operator. [ABSTRACT FROM AUTHOR]

As a lung cancer biomarker, exosomes were utilized for in vitro diagnosis to overcome the lack of sensitivity of conventional imaging and the potential harm caused by tissue biopsy. However, given the inherent heterogeneity of exosomes, the challenge of accurately and reliably recognizing subtle differences in the composition of exosomes from clinical samples remains significant. Herein, we report an artificial intelligence-assisted surface-enhanced Raman spectroscopy (SERS) strategy for label-free profiling of plasma exosomes for accurate diagnosis of early-stage lung cancer. Specifically, we build a deep learning model using exosome spectral data from lung cancer cell lines and normal cell lines. Then, we extracted the features of cellular exosomes by training a convolutional neural network (CNN) model on the spectral data of cellular exosomes and used them as inputs to a support vector machine (SVM) model. Eventually, the spectral features of plasma exosomes were combined to effectively distinguish adenocarcinoma in situ (AIS) from healthy controls (HC). Notably, the approach demonstrated significant performance in distinguishing AIS from HC samples, with an area under the curve (AUC) of 0.84, sensitivity of 83.3%, and specificity of 83.3%. Together, the results demonstrate the utility of exosomes as a biomarker for the early diagnosis of lung cancer and provide a new approach to prescreening techniques for lung cancer. [ABSTRACT FROM AUTHOR]

This study investigated the drivers and extended-range prediction of the mid-July to early August 2018 heatwaves over northwestern Europe, focusing on regional heatwave events over Scandinavia (SC) and Western Europe (WE). The persistent blocking regime (BL) was the most influential contributor for the 2018 heatwave over SC, and both the Atlantic Low regime (AL) and North Atlantic Oscillation (NAO) were secondary contributors for the heatwave, but with different effect directions. The major contributor to the heatwave over WE was AL. These causal relationships remained valid when the evolution of warm spells was considered. A multi-model ensemble of real-time forecasts from the subseasonal to seasonal (S2S) database captured the evolution of the warm spells over SC and WE up to 3 weeks in advance. However, the predictions of heatwave occurrence and significance for the two regions are unsatisfactory. BL and AL can be predicted 2 weeks in advance, resulting in the successful predictions of warm spells over SC and WE. Although variations in Azores High and NAO were captured in the forecasts, their contribution to the warm spells remains unclear. [ABSTRACT FROM AUTHOR]

Telomere maintenance is required for chromosome stability, and telomeres are typically elongated by telomerase following DNA replication. In both tumor and yeast cells that lack telomerase, telomeres are maintained via an alternative recombination mechanism. Previous studies have indicated that yeast Sgs1 and Top3 may work together to remove highly negative supercoils that are generated from recombination. However, the mechanism by which cells eradicate highly positive supercoils during recombination remains unclear. In the present study, we demonstrate that TOP2 is involved in telomere-telomere recombination. Disturbance of telomeric structure by RIF1 or RIF2 deletion alleviates the requirement for TOP2 in telomere-telomere recombination. In human telomerase-negative alternative lengthening of telomere (ALT) cells, TOP2α or TOP2β knockdown decreases ALT-associated PML bodies, increases telomere dysfunction-induced foci and triggers telomere shortening. Similar results were observed when ALT cells were treated with ICRF-193, a TOP2 inhibitor. Importantly, ICRF-193 treatment blocks ALT-associated phenotypes in vitro, causes telomere shortening, and inhibits ALT cell proliferation in mice. Taken together, these findings imply that TOP2 is involved in the ALT pathway, perhaps by resolving the highly positive supercoil structure at the front of the helicase. Inhibition of topoisomerase II may be a promising therapeutic approach that can be used to prevent cell proliferation in ALT-type cancer cells. [ABSTRACT FROM AUTHOR]

Solid–liquid phase change materials (PCMs) are a kind of important heat energy storage materials that can store/release great amounts of latent heat at a specific temperature or within a narrow temperature range and thus can be applied in a lot of fields related to heat energy storage or thermal management. However, their practical applications are still limited due to formidable challenges such as the risk of leakage, easy phase separation and low thermal conductivity, etc. Silica possesses the merits of cheap, high chemical and physical stability, flame retardancy and relatively high thermal conductivity. It can be applied as both shell material and supporting materials to obtain form-stable PCMs and thus address the aforementioned challenges. In this review, the recent progresses of silica-based form-stable PCMs were summarized. We introduced the main methods for the preparation of the silica-confined composite form-stable PCMs at first. Then, the physical and chemical properties of the reported silica-confined composite form-stable PCMs were summarized and discussed. Finally, some emerging research topics and challenges on silica-based composite form-stable PCMs are proposed. [ABSTRACT FROM AUTHOR]

Particulate lead (Pb) is a primary air pollutant that affects society because of its health impacts. This study investigates the source sectors of Pb associated with ambient fine particulate matter (PM2.5) over central-western Taiwan (CWT) with new constraints on the Pb-isotopic composition. We demonstrate that the contribution of coal-fired facilities is overwhelming, which is estimated to reach 35 ± 16% in the summertime and is enhanced to 57 ± 24% during the winter monsoon seasons. Moreover, fossil-fuel vehicles remain a major source of atmospheric Pb, which accounts for 12 ± 5%, despite the current absence of a leaded gasoline supply. Significant seasonal and geographical variations in the Pb-isotopic composition are revealed, which suggest that the impact of East Asian (EA) pollution outflows is important in north CWT and drastically declines toward the south. We estimate the average contribution of EA outflows as accounting for 35 ± 15% (3.6 ± 1.5 ng/m3) of the atmospheric Pb loading in CWT during the winter monsoon seasons. [ABSTRACT FROM AUTHOR]

Wind is one of the cleanest renewable energy resources. Through the "Thousand Wind Turbines Project", Taiwan is planning to increase the proportion of power generation from renewable energy and has set a target of 5.7 GW for offshore wind by 2025. The effects of future offshore wind farms (OWFs) over the Taiwan Strait on the atmospheric environment have not been evaluated. This study examined the potential effects of proposed OWFs on the atmospheric environment if the OWFs had existed during Tropical Storm Haitang (2017) by using Weather Research and Forecasting (WRF) model. A small set of ensemble simulations was conducted for studying the sensitivity of the ambient conditions in the region to the wind farm locations, the number and density of the turbines, and the initial time of simulations. Following the landfall and northward movement of Tropical Storm Haitang, a series of complex interactions between the typhoon circulation and the wind farm emerged, including small time slots of wake effect and mountain blocking effect. The combination of these rapidly changing OWFs-related effects contributed to a weak reduction in precipitation (− 1.08 mm) and hub-height wind speed (− 0.25 m s−1), as well as minimal warming near the surface (+ 0.13 °C) over southern Taiwan. [ABSTRACT FROM AUTHOR]

We are concerned with the issue of detecting changes and their signs from a data stream. For example, when given time series of COVID-19 cases in a region, we may raise early warning signals of an epidemic by detecting signs of changes in the data. We propose a novel methodology to address this issue. The key idea is to employ a new information-theoretic notion, which we call the differential minimum description length change statistics (D-MDL), for measuring the scores of change sign. We first give a fundamental theory for D-MDL. We then demonstrate its effectiveness using synthetic datasets. We apply it to detecting early warning signals of the COVID-19 epidemic using time series of the cases for individual countries. We empirically demonstrate that D-MDL is able to raise early warning signals of events such as significant increase/decrease of cases. Remarkably, for about 64 % of the events of significant increase of cases in studied countries, our method can detect warning signals as early as nearly six days on average before the events, buying considerably long time for making responses. We further relate the warning signals to the dynamics of the basic reproduction number R0 and the timing of social distancing. The results show that our method is a promising approach to the epidemic analysis from a data science viewpoint. [ABSTRACT FROM AUTHOR]

The displacement at various measurement points is a critical indicator that can intuitively reflect the operational properties of a dam. It is important to analyse displacement monitoring data in a timely manner and make reliable predictions of dam safety. This paper proposes a GPR-based model for dam displacement forecasting. The input variables of the monitoring model consider hydraulic factors, thermal factors and irreversible factors, and the output variables are the observed displacements of the dam. An example analysis based on the proposed method is performed on a prototype gravity dam, and the performance of different simple/combined covariance functions is investigated to obtain the optimal choice. Compared to multiple linear regression, radial basis function network (RBFN) and support vector machine (SVM) methods, the results indicate that the GPR-based model with a combined covariance function significantly improves the prediction accuracy. The proposed model can effectively overcome the over-learning and poor robustness issues of approaches such as RBFN and SVM. In addition, the GPR-based forecasting model has the advantages of simplicity in the training process and the capacity to provide a probabilistic output. [ABSTRACT FROM AUTHOR]

Li metal has the highest specific capacity (3860 mA h g−1) and the lowest electrochemical potential (− 3.04 V vs. SHE) of available metal anodes. Together with the high specific capacity of sulfur cathodes (1670 mA h g−1), Li metal-S batteries are a promising candidate to achieve high energy density batteries for electric vehicles and future industry. However, Li metal anodes suffer from corrosive reactions with electrolytes, a theoretically infinite volume change, and the growth of dendrites during electrochemical cycling. To realize the practical application of Li metal-S batteries, protective layers or artificial solid-electrolyte interphase (ASEI) layers have been applied to the surface of Li metal. These ASEI layers demonstrate capabilities to suppress the growth of dendrites and mitigate side reactions, which enhance the performance and safety of Li metal anodes in liquid-electrolyte systems, though there are still limitations and challenges. The development of solid-state electrolytes as artificial SEIs provides a promising route to suppress the issues of dendrite formation and the polysulfide "shuttle effect" in Li-S chemistry; however, the improvement in the interfacial compatibility and stability between the Li metal and the solid-state electrolyte is crucially needed. In this review, we summarize different types of ASEI layers used to protect Li metal, especially in Li-S batteries, with both liquid- and solid-electrolyte systems. We also briefly introduce the concept of anode protection of Mg metal and its application in Mg-S batteries. Perspectives regarding the further development and improvement of ASEI layers for Li metal and Mg metal are discussed. [ABSTRACT FROM AUTHOR]

Obesity is reaching global epidemic proportions as a result of factors such as high-calorie diets and lack of physical exercise. Obesity is now considered to be a medical condition, which not only contributes to the risk of developing type 2 diabetes mellitus, cardiovascular disease and cancer, but also negatively affects longevity and quality of life. To combat this epidemic, anti-obesogenic approaches are required that are safe, widely available and inexpensive. Several plants and mushrooms that are consumed in traditional Chinese medicine or as nutraceuticals contain antioxidants, fibre and other phytochemicals, and have anti-obesogenic and antidiabetic effects through the modulation of diverse cellular and physiological pathways. These effects include appetite reduction, modulation of lipid absorption and metabolism, enhancement of insulin sensitivity, thermogenesis and changes in the gut microbiota. In this Review, we describe the molecular mechanisms that underlie the anti-obesogenic and antidiabetic effects of these plants and mushrooms, and propose that combining these food items with existing anti-obesogenic approaches might help to reduce obesity and its complications. [ABSTRACT FROM AUTHOR]

NiCoS-based nanostructured films have been grown directly onto nickel foams by a facile two-step method, involving the growth of NiCo-precursor and subsequent conversion into NiCoS via a sulfidation process, with the aid of sodium dodecyl surfactant (SDS). This synthesis method enables the fabrication of binder- and conductive additive-free electrodes for supercapacitors. The influence of the surfactant on the crystal structure, morphology, and electrochemical performance of the electrodes has been investigated. The NiCoS-SDS films exhibit a complex cellular and hierarchical porous structure, which are different from NiCoS-pure films with nanotube arrays structure. Moreover, the electrochemical tests show that the NiCoS-SDS nanostructured electrode exhibits an ultrahigh specific capacitance of 2519 F g at 0.5 A g, which doubles that of the NiCoS-pure nanotube arrays electrode. In addition, the NiCoS-SDS electrode exhibits excellent cycling stability with 90.7 % capacitance retention at 10 A g after 8000 cycles. In view of the low cost and superior electrochemical performance, the NiCoS-SDS electrodes are promising electrode materials for high-performance supercapacitors. [ABSTRACT FROM AUTHOR]

The 2008 M 7.9 Wenchuan earthquake formed two coseismic surface rupture zones with the trend of N35°E, known as the Beichuan-Yingxiu rupture and the Pengguan rupture. The Beichuan-Yingxiu rupture is the principle one with abundant fault gouge development along its length. In the exploratory trench at the Saba village along the Beichuan-Yingxiu rupture, the new fault gouge zone is only ~3 mm wide, which suggests that fault slip was constrained in a very narrow zone. In this study, we thus carried out detailed microstructural and mineral component analysis on the oriented fault gouge samples from the Saba exploratory trench to understand their features and geological implication. The results show that different microstructures of localized brittle deformation can be observed in the fault gouges, including Y-shear, R1-shear, R2-shear, P-shear as well as tension fracture, bookshelf glided structure and so on. These microstructures are commonly recognized as the product of seismic fault slipping. Furthermore, within the area between two parallel Y-shears of the fault gouge, a few of microstructures of distributed ductile deformations were developed, such as P-foliation, elongation and asymmetrical trailing structure of detrital particles. The microstructure features of fault gouges implicate the thrust movement of the fault during the Wenchuan earthquake. In addition, the fault gouge has less quartz and feldspar and more clay than the surrounding rocks, which indicates that some quartz and feldspar in the surrounding rocks were transformed into clay, whereas the fault gouge has more illite and less illite/montmorillonite mixed layers than the surrounding rocks, which shows that the illite/montmorillonite mixed layer was partly converted into illite due to temperature increasing induced by coseismic fault slipping friction (also being affected partly by the chemical action of solutions). Such microstructures features and mineral component changes recorded the information of fault slip and provide criterions for discussing the genesis of fault gouge and recognition of the direction of fault movement. [ABSTRACT FROM AUTHOR]

Tumors can recruit, induce, and expand regulatory T cells (Tregs) to suppress antitumor immune responses for survival and progression. The complicated tumor-related Treg subsets and their functional mechanisms are not fully addressed yet. We have previously identified a novel CD4CD69CD25Foxp3 Treg subset in tumor-bearing mice, which suppresses CD4 T cell response via membrane-bound transforming growth factor beta 1 (mTGF-β1) and then promotes tumor progression. In hepatocellular carcinoma patients, here, we identified tumor-infiltrating human CD4CD69 Tregs which represent ~67.2 % of tumor-infiltrating CD4 T cells that is significantly higher than conventional CD4CD25Foxp3 Tregs. They expressed mTGF-β1, PD-1, and CTLA-4, but not CD25 or Foxp3, and only produced a little interleukin (IL)-10 and TGF-β1. More importantly, they significantly suppressed CD4 T cell response via mTGF-β1 in vitro. Furthermore, the percentage of these CD4CD69 Tregs in tumor tissue was significantly correlated with tumor progression, which is more pronounced at the late stage of cancer patients. Thus, we have identified a tumor-induced new population of human CD4CD69 Tregs in cancer patients with phenotype of CD25Foxp3mTGF-β1CTLA-4PD-1, and these Tregs can suppress antitumor immune response via mTGF-β1. Our results not only enrich the family of Treg subsets, providing new mechanistic insight to tumor-induced immune suppression in human, but also suggest a potential target for cancer immunotherapy. Key message: [ABSTRACT FROM AUTHOR]

In this study, we demonstrated a blue phosphorescent organic light-emitting diode (BPOLED) based on a host with two carbazole and one trizole (2CbzTAZ) moiety, 9,9′-(2-(4,5-diphenyl-4H-1,2,4-triazol-3-yl)-1,3-phenylene)bis(9H-carbazole), that exhibits bipolar transport characteristics. Compared with the devices with a carbazole host (N,N'-dicarbazolyl-3,5-benzene, (mCP)), triazole host (3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole, (TAZ)), or a physical mixture of mCP:TAZ, which exhibit hole, electron, and bipolar transport characteristics, respectively, the BPOLED with the bipolar 2CbzTAZ host exhibited the lowest driving voltage (6.55 V at 10 mA/cm2), the highest efficiencies (maximum current efficiency of 52.25 cd/A and external quantum efficiency of 23.89%), and the lowest efficiency roll-off, when doped with bis[2-(4,6-difluorophenyl)pyridinato-C2,N](picolinato)iridium(III) (FIrpic) as blue phosphor. From analyses of light leakage of the emission spectra of electroluminescence, transient electroluminescence, and partially doped OLEDs, it was found that the recombination zone was well confined inside the emitting layer and the recombination rate was most efficient in a 2CbzTAZ-based OLED. For the other cases using mCP, TAZ, and mCP:TAZ as hosts, electrons and holes transported with different routes that resulted in carrier accumulation on different organic molecules and lowered the recombination rate. [ABSTRACT FROM AUTHOR]

Riverine dissolved organic carbon (DOC), responsible for riverine productivity, is rarely documented in subtropical small mountainous rivers (SMRs) where high rainfall and steep slopes are the main features. This study investigated the DOC export at eight sites in three Taiwan SMRs to characterize the dynamics and controlling factors of DOC transport. Results showed that the mean DOC concentration of ~0.78 mg L−1 is much lower than the global average of ~5.29 mg L−1. However, the mean DOC yield, ~22.51 kg-C ha−1 yr−1, is higher than the global average of 14.4-19.3 kg-C ha−1 yr−1. Comparing with worldwide rivers from literature, the annual discharge, slope, and SOC (soil organic carbon) are controlling factors as expected, though they influence in different ways. SOC stock likely regulated by elevation-dependent biomes dominate the DOC supply, while slope restrains the DOC generation due to shallow soil depth and fast runoff velocity. However, the abundant discharge flushing this persistent low supply leads to a large DOC export in the SMRs. Furthermore, the DOC dynamics during typhoon periods showed a clockwise hysteresis, suggesting that the DOC is mainly from the riparian zone or downslope area during the rising limb of the hydrograph. This study elucidates the DOC transport in SMRs and provides an atypical yet significant piece of understanding on DOC transport in a global context. [ABSTRACT FROM AUTHOR]