Recently, the discovery and development of lead-free perovskite quantum dots (QDs) that are eco-friendly and stable has become an active research area in low-cost lighting and display fields. ...However, the low photoluminescence quantum yield (PLQY) caused by the residual surface states of such QDs severely hinders their practical applications and commercialization. In this work, a strategy of employing water-induced nanocomposites was proposed to improve the PLQY of cesium bismuth halide (Cs
3
Bi
2
X
9
) QDs, and a substantial enhancement by ∼130% (from 20.2% to 46.4%) was achieved by an optimized water treatment of Cs
3
Bi
2
Br
9
QDs. A detailed analysis indicated that Cs
3
Bi
2
Br
9
/BiOBr nanocomposites, in which the Cs
3
Bi
2
Br
9
QD core was encapsulated into a BiOBr matrix, can effectively suppress the surface defects of QDs, resulting in a longer PL lifetime and a larger exciton binding energy compared with the pristine sample. Finally, the Cs
3
Bi
2
Br
9
/BiOBr nanocomposites were used as the color-converting phosphors for down-conversion white light-emitting devices, which show a good operation stability in ambient air, significantly better than the reference device constructed with conventional lead-halide perovskites. We believe that the method used here provides an effective strategy to improve the fluorescence efficiency of lead-free perovskite QDs, which will create opportunities for their applications in lighting and displays.
We proposed a strategy of employing water-induced Cs
3
Bi
2
Br
9
/BiOBr nanocomposites to achieve a substantial enhancement in photoluminescence quantum yield by ∼130%.
Recently, inorganic halide perovskite (CsPbX3, X = Cl, Br, I) quantum dots (QDs) have attracted tremendous research interests because of their great potential for application in the fields of ...low-cost light sources and displays. However, the unsatisfactory structural and chemical stabilities of such materials are the main obstacles hindering reliable device operation significantly. In this study, we successfully prepared CsPbBr3/silica QD composites through a simple sol-gel reaction by using tetramethoxysilane as a single molecule precursor. The as-prepared CsPbBr3/silica QD composites demonstrated substantially improved stability against heat, light, and environmental oxygen/moisture. Besides, a relatively narrower photoluminescence linewidth and higher quantum yield were achieved compared with that of fresh CsPbBr3 QDs. Furthermore, the CsPbBr3 QDs/silica composites were applied as color-converting layer curing on blue light-emitting diodes (LEDs) for white LED applications. Finally, a high power efficiency of 63.5 lm W-1 was obtained and the light emission could be efficiently sustained over 13 h without any decay in the continuous current mode, demonstrating remarkable operation stability than that reported previously. It can be anticipated that the excellent properties and facile processing technique used here will make perovskite QDs/silica composites attractive for applications in optoelectronics and industrial fields.
Halide perovskite-based photodetectors, because of their fundamental scientific importance and practical applications in the military and civil fields, have drawn worldwide attention in recent years. ...However, the toxicity and instability issues are major challenges for their mass production and commercialization. In this study, for the first time, we report the use of the one-step spin-coating method for the preparation of lead-free double perovskite Cs
2
AgBiBr
6
thin films for photodetector applications. The morphology, crystallinity, and optical properties of the as-grown Cs
2
AgBiBr
6
thin films were first investigated. Further, symmetrically structured photoconductive detectors were fabricated and characterized. The device performance was remarkable in terms of a high responsivity of 7.01 A W
−1
, an on/off photocurrent ratio of 2.16 × 10
4
, a specific detectivity of 5.66 × 10
11
Jones, an external quantum efficiency of 2146%, and a fast response speed of 956/995 μs. More importantly, the unencapsulated photodetectors demonstrate remarkable operational stability over the aging test (36 h, 35-45% humidity), and the photodetection ability can be almost maintained. Moreover, after storage for two weeks in ambient air, the proposed photodetectors can be efficiently sustained, demonstrating remarkable stability against water and oxygen degradation. Our results indicate that lead-free double perovskite Cs
2
AgBiBr
6
is potentially an environmentally friendly alternative to fabricate high-efficiency and stable perovskite photodetectors for practical applications.
High-performance and air-stable perovskite photodetectors were fabricated using lead-free double perovskite Cs
2
AgBiBr
6
thin films as light absorbers.
Conjugated polymers (CPs) have been developed quickly as an emerging functional material with applications in optical and electronic devices, owing to their highly electron‐delocalized backbones and ...versatile side groups for facile processibility, high mechanical strength, and environmental stability. CPs exhibit multistimuli responsive behavior and fluorescence quenching properties by incorporating azobenzene functionality into their molecular structures. Over the past few decades, significant progress has been made in developing functional azobenzene‐based conjugated polymers (azo‐CPs), utilizing diverse molecular design strategies and synthetic pathways. This article comprehensively reviews the rapidly evolving research field of azo‐CPs, focusing on the structural characteristics and synthesis methods of general azo‐CPs, as well as the applications of charged azo‐CPs, specifically azobenzene‐based conjugated polyelectrolytes (azo‐CPEs). Based on their molecular structures, azo‐CPs can be broadly categorized into three primary types: linear CPs with azobenzene incorporated into the side chain, linear CPs with azobenzene integrated into the main chain, and branched CPs containing azobenzene moieties. These systems are promising for biomedical applications in biosensing, bioimaging, targeted protein degradation, and cellular apoptosis.
Azobenzene, a versatile functional group, is commonly used as a stimuli‐responsive probe due to its trans–cis isomerization capabilities, electron‐withdrawing properties, ease of synthesis, and derivatization. Azobenzene‐based conjugated polymers and conjugated polyelectrolytes have attracted considerable attention as their optical and electronic properties for their multistimuli responsive behavior and fluorescence quenching properties.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
In recent years, the metal-halide perovskites have attracted intensive attention in the field of white light-emitting devices (WLEDs). However, their further commercial applications are severely ...hampered by the poor stability and lead toxicity of such materials. In this work, we demonstrate two types of lead-free ternary copper halides (blue-emissive Cs
3
Cu
2
I
5
and yellow-emissive CsCu
2
I
3
), which were synthesized by a convenient supersaturated recrystallization method at room temperature. Both materials have particularly good crystallinity and excellent stability against ultraviolet light, heat, and air oxygen/moisture. Temperature-dependent photoluminescence (PL) and time-resolved PL decay measurements confirm that the highly luminescent and largely Stokes-shifted broadband emission of both materials derived from the self-trapped exciton-related recombination. By using a mixture of Cs
3
Cu
2
I
5
and CsCu
2
I
3
as the down-conversion phosphors, a high-performance WLED is demonstrated with the color coordinates of (0.324, 0.330), a correlated color temperature of 5877 K, and a color rendering index of 88.4. Also, a high luminous efficiency of 54.6 lm W
−1
is realized, which is the highest value among the lead-free perovskite-based WLEDs. More importantly, the studied WLED demonstrates excellent operation stability, and almost no emission degradation occurs after continuously working for 100 h in air ambient. The results suggest that such ternary copper halides may be potentially attractive candidates for the fabrication of efficient, stable, and environmentally friendly WLEDs.
Blue-emissive Cs
3
Cu
2
I
5
and yellow-emissive CsCu
2
I
3
microscale crystals were synthesized by a facile supersaturated recrystallization method at room temperature, and a stable WLED was demonstrated by using both materials as down-conversion phosphors.
In ICT-enabled teams, innovation involves intensive adoption of ICTs and knowledge sharing among all members rather than a few experts. However, ICTs bring not only efficiency but also technostress, ...which hinders knowledge sharing and innovative practices among team members. To investigate this paradox, we drew on the job demand-control (JDC) model derived from the control theory of occupational stress to construct a theoretical framework regarding the collective influence of technostress, learning goal orientation, perceived team learning climate, and intra-team knowledge sharing on the innovative practices of ICT-enabled team members. Our multiple regression analyses of 481 ICT consultants’ responses show that intra-team knowledge sharing positively influenced innovative practices; perceived team learning climate positively moderated this relationship. Further, technostress negatively influenced intra-team knowledge sharing; learning goal orientation positively influenced intra-team knowledge sharing, although the relationship demonstrated an inverted U-shape. Finally, learning goal orientation negatively moderated the relationship between technostress and intra-team knowledge sharing. Our results shed light on the paradox regarding ICT adoption, with theoretical implications for employee-driven innovation, team learning climate, intra-team knowledge sharing, learning goal orientation, and managerial practices about the design and adoption of ICT-enabled jobs.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Polydimethylsiloxane (PDMS) micropillar arrays are widely used in research labs and engineering fields as analytical tools for various purposes. When the micropillar length or density surpasses a ...critical value, micropillars tend to collapse with each other and become unusable. Restoring collapsed PDMS micropillars typically involves the use of low surface tension solvents and ultrasound sonication, but such approach has received little success to date. In this work, we examined the effectiveness of different types of solvents for restoring collapsed PDMS micropillar arrays and show that the swelling ratio of PDMS in selected solvents constitutes an important factor in the effectiveness of restoring collapsed PDMS micropillars. Our results could be a promoter in recycling PDMS micropillar arrays and achieving economic and social benefits.
Solvent-induced polymer swelling effect promoted PDMS micropillar arrays recovery through the formation of liquid bridge.
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IJS, KILJ, NUK, UL, UM, UPUK
In existing image recognition algorithms, the position and sequence of image pixels are key factors that affect the accuracy of image recognition. Therefore, the topological invariance of complex ...networks has led to the recognition that applying complex networks to image recognition analysis will significantly reduce the impact of images on classification recognition accuracy when rotation, translation, and scaling occur. However, most studies on image classification by complex networks have focused on a single network, lacking dynamic evolution with the networks among them. In this paper, we propose a new complex network classification method that combines complex networks and convolutional neural networks(CNN) to train classification using deep learning. We show that the method has high classification accuracy and distinct network features and compares well with a single complex network approach. In addition, to make the distribution of the degree histogram of the image more uniform and concentrated, the original formula for calculating the power value was optimized to reduce the influence of the radius parameter on the power value.
ObjectivePatients with spontaneous intracerebral hemorrhage (sICH) are susceptible to venous thromboembolism (VTE) including pulmonary embolism (PE) and deep venous thrombosis (DVT) due to a variety ...of risk factors. There are few studies regarding the predictive value of D-dimer for VTE in patients with sICH, and the anticoagulation therapy for these patients are still controversial. The objective of this study is to study the independent predictors of VTE in sICH patients. The rates of anticoagulation therapy and hemorrhagic evens were also investigated.MethodsRetrospective review of patients with sICH admitted to the First Affiliated Hospital of Dalian Medical University from 2012 to 2022 and who developed VTE (PE and/or DVT) during hospitalization. A similar number of sICH patients without VTE were randomly selected into the control group. A variety of clinical characteristics were compared between groups. Univariate and multivariate analyses were performed to identify independent predictors of VTE in patients with sICH.ResultsA total of 270 sICH patients were enrolled in this study, including 132 patients with VTE and 138 patients without VTE. After adjusting for other confounders, the maximum level of D-dimer during hospitalization (odds ratio OR 1.061, 95 % confidence interval (CI) 1.014–1.110), Glasgow coma scale (GCS) on admission (OR 1.347, 95 % CI 1.110–1.634), modified Rankin Scale (mRS) at discharge (OR 2.578, 95 % CI 1.546–4.298), neutrophil count (OR 1.056, 95 % CI 1.025–1.088) and hospitalization time (OR 1.089, 95 % CI 1.018–1.164) were independently associated with the sICH patients who developed VTE. The maximum D-dimer plasma level of 5.655 mg/L during hospitalization was the optimal threshold to indicate sICH patients developing VTE with a sensitivity of 83.3 % and a specificity of 67.4 %. No patients with sICH received prophylactic anticoagulation therapy against VTE in the present study. A total of 57.6 % (76/132) of the sICH patients with VTE were administered anticoagulant therapy and the rate of hemorrhagic complication was 9.2 %.ConclusionssICH patients with increased levels of D-dimer, higher GCS scores, higher mRS scores, increased neutrophil counts and longer hospitalization time are more likely to develop VTE complications. Routine and serial monitoring of the D-dimer values may be useful in patients with sICH, and VTE should be considered when the plasma level of D-dimer increases to 5.655 mg/L during hospitalization. In tertiary hospitals in China, the rate of sICH patients with VTE receiving anticoagulation treatment is low. Further studies are necessary to explore the safety and efficacy of VTE therapeutic anticoagulation in patients with sICH.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Purpose
This study aims to examine newcomers experiencing maladjustment due to cognitive diversity, specifically, how maladjustment affects their turnover intentions; the mediating role of reported ...workplace bullying; and the buffering effect of perceived inclusive practices in the hospitality sector.
Design/methodology/approach
The authors collected time-lagged data from 403 respondents and analyzed the data through hierarchical regression analyses using statistical package for the social sciences (SPSS) 25.0.
Findings
Role ambiguity, low self-efficacy and social exclusion could each lead to newcomers’ reported workplace bullying (NRB). Perceived inclusive practices buffered the impacts of role ambiguity and social exclusion. NRB negatively mediated the relationships between role ambiguity and NRB; and social exclusion and NRB.
Practical implications
Hospitality practitioners should specify work procedures to minimize role ambiguities and record service processes to correct mistakes, reward veterans who help newcomers improve self-efficacy, invite newcomers to develop inclusive practices and review employee comments on third-party platforms to understand factors responsible for turnover intention.
Originality/value
This study contextualized cognitive diversity into newcomers’ maladjustment-bullying-turnover model in China’s hospitality industry. It highlighted the buffering effect of perceived inclusive practices in the relationships between maladjustment and reported bullying and turnover intentions among newcomers and confirmed the important role of self-efficacy in addressing adverse work events.
