Achieving structure optimizing and component regulation simultaneously in the ZnIn2S4‐based photocatalytic system is an enormous challenge in improving its hydrogen evolution performance. 3D ...hollow‐structured photocatalysts have been intensively studied due to their obvious advantages in solar energy conversion reactions. The synthesis of 3D hollow‐structured ZnIn2S4, however, is limited by the lack of suitable template or synthesis methods, thereby restricting the wide application of ZnIn2S4 in the field of photocatalysis. Herein, Ce‐doped ZnIn2S4 photocatalysts with hollow nanocages are obtained via one‐step hydrothermal method with an ordered large‐pore tetrakaidecahedron cerium‐based metal–organic frameworks (Ce‐MOFs) as template and Ce ion source. The doping of Ce and the formation of ZnIn2S4 tetrakaidecahedron hollow nanocages with ultrathin nanosheet subunits are simultaneously induced by the Ce‐MOFs, making this groundbreaking work. The Ce‐doped ZnIn2S4 with a nonspherical 3D hollow nanostructure inherit the tetrakaidecahedron shape of the Ce‐MOF templates, and the shell is composed of ultrathin nanosheet subunits. Both theoretical and experimental results indicate that the doping of Ce and the formation of hollow nanocages increase light capture and the separation of photogenerated charge carriers.
Ce‐doped ZnIn2S4 photocatalysts with hollow nanocages are obtained via one‐step hydrothermal method with an ordered large‐pore tetrakaidecahedron cerium‐based metal–organic frameworks as template and Ce ion source.
The ultrafine phase change composite fibers based on polyethylene glycol/poly (dl-lactide) (PEG/PLA) blends with various PEG/PLA mass ratios (100/100, 120/100, 150/100, 180/100, 200/100), in which ...PLA acts as polymer matrix and PEG with the molecular weight of 8000 acts as phase change working ingredient, were fabricated via electrospinning. The surface morphology, composition, crystallization properties, thermal properties and heat storage/release performances of the composite fibers have been systematically studied by scanning electronic microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), thermogravimetry analysis (TG) and temperature–time curves, respectively. The results show that the composite fibers have good morphology with smooth surface and uniform diameter distribution when the mass ratio of PEG/PLA varies from 100/100 to 200/100, and the average fiber diameter increases with increasing PEG content. The composite fibers have available heat storage capacity with the melting enthalpy ranging from 54.8J/g (PEG/PLA 100/100) to 74.7J/g (PEG/PLA 200/100), and the degradation temperatures of the fibers are higher than 320°C. The composite fibers own expected reusability and thermal reliability from DSC cycle test, and they show form stable characteristic, balanced phase change behaviors and good heat storage/release properties after thermal treatment. The prepared phase change composite fibers have potential applications in smart textiles, medicine cares and electric devices for thermal energy storage and temperature regulation.
•Ultrafine PEG/PLA phase change fibers were fabricated by electrospinning.•The maximum PEG/PLA mass ratio of fibers with good morphology reaches 200/100.•The form stable PCFs have high enthalpies, good thermal reliability and stability.•Heat storage/release properties of the composite fibers have been tested.
The engineering of a 3T human MRI scanner equipped with 300mT/m gradients – the strongest gradients ever built for an in vivo human MRI scanner – was a major component of the NIH Blueprint Human ...Connectome Project (HCP). This effort was motivated by the HCP's goal of mapping, as completely as possible, the macroscopic structural connections of the in vivo healthy, adult human brain using diffusion tractography. Yet, the 300mT/m gradient system is well suited to many additional types of diffusion measurements. Here, we present three initial applications of the 300mT/m gradients that fall outside the immediate scope of the HCP. These include: 1) diffusion tractography to study the anatomy of consciousness and the mechanisms of brain recovery following traumatic coma; 2) q-space measurements of axon diameter distributions in the in vivo human brain and 3) postmortem diffusion tractography as an adjunct to standard histopathological analysis. We show that the improved sensitivity and diffusion-resolution provided by the gradients are rapidly enabling human applications of techniques that were previously possible only for in vitro and animal models on small-bore scanners, thereby creating novel opportunities to map the microstructure of the human brain in health and disease.
•Diffusion spectrum imaging to study traumatic coma recovery•In vivo human axon diameter measurements using 300mT/m gradients•High-resolution (0.6mm isotropic) diffusion imaging in whole, fixed human brain
Social influence drives human selection behaviours when numerous objects competing for limited attentions, which leads to the 'rich get richer' dynamics where popular objects tend to get more ...attentions. However, evidences have been found that, both the global information of the whole system and the local information among one's friends have significant influence over the one's selection. Consequently, a key question raises that, it is the local information or the global information more determinative for one's selection? Here we compare the local-based influence and global-based influence. We show that, the selection behaviour is mainly driven by the local popularity of the objects while the global popularity plays a supplementary role driving the behaviour only when there is little local information for the user to refer to. Thereby, we propose a network model to describe the mechanism of user-object interaction evolution with social influence, where the users perform either local-driven or global-driven preferential attachments to the objects, i.e., the probability of an objects to be selected by a target user is proportional to either its local popularity or global popularity. The simulation suggests that, about 75% of the attachments should be driven by the local popularity to reproduce the empirical observations. It means that, at least in the studied context where users chose businesses on Yelp, there is a probability of 75% for a user to make a selection according to the local popularity. The proposed model and the numerical findings may shed some light on the study of social influence and evolving social systems.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In this paper, a technology and device for large-scale fabrication of nanofibers called tiny-needle-spaced electrostatic-induction-assisted solution blowing spinning (TESBS) was developed. The ...airflow stretching force is used as the initial driving force for jet formation in TESBS, which avoids the electric field interference existing in the jet formation stage of multi-needle electrospinning(MES). The addition of an induced electric field in TESBS solves the problem of mutual merging of jets in multi-needle solution blowing spinning (MSBS). The needle spacing of TESBS can be as small as 1 mm, which is much smaller than MES (100 mm) and MSBS (3 mm). The substantial reduction in needle spacing can increase the arrangement density of blunt needles, thereby increasing the output of nanofibers. Compared with MSBS, the average diameter and diameter standard deviation of TESBS nanofibers can be reduced by 52.6% and 78.7%, respectively. Compared with MES, the uniformity of the TESBS nanofiber web has been significantly improved. The formula for the critical needle spacing to ensure that the TESBS jets do not merge with each other was derived. The output of 15-needle TESBS can reach as high as 3 ml/min. The average diameter of TESBS nanofibers decreases with the decrease in injection speed or the increase in voltage. The distance between the needle and the receiver has little effect on the average fiber diameter. TESBS nanofibers with good quality and high yield have broad and bright application prospects in many fields.
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•Digital innovation has enabled the development of new collaborative networks such as digital business ecosystems.•There have been limited attempts to critically review and synthesise digital ...business ecosystem research.•This study systematically analysed and critically reviewed 101 research articles on digital business ecosystem.•This study combined systematic literature review approach with grounded theory literature review method as the overall research strategy.•The findings suggest that digital business ecosystem research can be classified into four main themes.
Digital innovation has radically changed how organisations collaborate and compete. Coupled with this change are new collaborative value creation networks such as digital business ecosystems (DBEs). DBE is a socio-technical network of individuals, organisations and technologies that collectively co-create value. Since the emergence of DBE over a decade ago, there have been limited attempts to critically review and synthesise the body of knowledge presented over the years. Thus, the purpose of this paper is to fill this gap in DBE research by: (1) developing a comprehensive framework that synthesises and provides an overall direction of DBE research; (2) pointing out gaps in DBE literature; and (3) providing future research directions. To address this purpose, we systematically analysed 101 research articles on DBE. The findings provide insightful revelations to address some limitations in the current DBE research. As such, this study makes important contributions and serves as a useful resource for future DBE studies and practice.
Hierarchical ZnSnO3/Zn2SnO4 porous hollow octahedrons were constructed using the method of combining the acid etching process with the in situ decoration technique for photovoltaic and photocatalytic ...applications. The composite was used as photoanode of the dye-sensitized solar cells (DSSCs), an overall 4.31% photovoltaic conversion efficiency was obtained, nearly a 73.1% improvement over the DSSCs that used Zn2SnO4 solid octahedrons. The composite was also determined to be a high-performance photocatalyst for the removal of heavy metal ion Cr (VI) and antibiotic ciprofloxacin (CIP) in single and co-existing systems under simulated sunlight irradiation. It was remarkable that the composite displayed good reusability and stability in a co-existing system, and the simultaneous removal performance could be restored by a simple acid treatment. These improvements of solar energy utilization were ascribed to the synergetic effect of the hierarchical porous hollow morphology, the introduction of ZnSnO3 nanosheets, and the heterojunction formed between ZnSnO3 and Zn2SnO4, which could improve light harvesting capacity, expedite electron transport and charge-separation efficiencies.
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► Antagonistic effects between Cr and Ni were mainly found in CCK-8 assay. ► Synergistic oxidative stress effects were partially found between Cr and Ni compounds. ► Synergistic DNA ...damage effects were partially found between Cr and Ni compounds.
In the present study, human B lymphoblastoid cells were exposed to potassium dichromate and/or nickel chloride for 24h or 48h. The cell viability and DNA damage induced by these compounds was measured with the CCK-8 assay and Comet assay, respectively. In addition, the generation of reactive oxygen species (ROS) and the levels of malondialdehyde (MDA) were measured using commercially available kits. Our results indicated that potassium dichromate could decrease cell viability and induce DNA damage in human B lymphoblastoid cells in a time – and concentration – dependent manner, but the toxicity of nickel chloride was not so obvious at concentrations used in our study. The results of ROS showed that both two compounds could only induce weak elevation of ROS level, but MDA levels were significantly enhanced. Antagonistic effects of cytotoxicity were mainly found between Cr (VI) and Ni (II), and synergistic effects of DNA damage and oxidative stress were partially found between these two compounds. Moreover, there were good correlations between the results of comet assay and the results of oxidative stress assays. It is suggested that synergistic DNA damage induced by simultaneously exposure of hexavalent chromium and nickel compounds is possibly related to oxidative stress.
Web service is one of the most fundamental technologies in implementing service oriented architecture (SOA) based applications. One essential challenge related to web service is to find suitable ...candidates with regard to web service consumer’s requests, which is normally called web service discovery. During a web service discovery protocol, it is expected that the consumer will find it hard to distinguish which ones are more suitable in the retrieval set, thereby making selection of web services a critical task. In this paper, inspired by the idea that the service composition pattern is significant hint for service selection, a personal profiling mechanism is proposed to improve ranking and recommendation performance. Since service selection is highly dependent on the composition process, personal knowledge is accumulated from previous service composition process and shared via collaborative filtering where a set of users with similar interest will be firstly identified. Afterwards a web service re-ranking mechanism is employed for personalised recommendation. Experimental studies are conduced and analysed to demonstrate the promising potential of this research.
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