A novel fluorescent biosensing paltform has been developed for probing and recognizing biomolecular interactions on the basis of the excellent fluorescent properties of DNA-AuNCs and the good ...quenching ability of MnO2 sheets.
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•We developed a new fluorescence sensing platform for probing biomolecular.•Low-cost MnO2 sheets were used as novel fluorescent quencher.•DNA templated AuNCs were utilized for fluorescent indicator and molecular recognition.•This strategy was free of any fluorescence dye label and other complex design.•The combination of DNA-AuNCs and MnO2 sheets brings novel opportunities in bioanalysis.
A label-free and universal fluorescence biosensing paltform has been constructed for probing and recognizing biomolecular interactions based on the excellent fluorescent properties of poly(adenine) (poly A) DNA templated-Au nanoclusters (DNA-AuNCs) and the good quenching ability of MnO2 sheets. Due to the high quenching efficiency of MnO2 sheets, the luminescence of DNA-AuNCs was decreased. Because single-stranded DNA-AuNCs was adsorbed onto the surface of MnO2 sheets through the physical absorption behavior between nucleobases of single-stranded DNA and the basal plane of MnO2 sheets. When the target DNA was introduced, the DNA-AuNCs could hybridize with the target DNA and form double-stranded duplex DNA structures, which resulting in the desorption of DNA-AuNCs from the surface of MnO2 sheets. Thus, the fluorescence signal of system was recovered. Similarly, in the presence of target substrate, aptamer-substrate complexes formed and resulted in the luminescence of DNA-AuNCs. By exploring DNA-AuNCs as signal reporter and MnO2 sheets as the quencher, this strategy could avoid the complex labelling process of the DNA probe and offer the advantages of simplicity and cost efficiency.
Photodetectors with excellent detecting properties over a broad spectral range have advantages for the application in many optoelectronic devices. Introducing imperfections to the atomic lattices in ...semiconductors is a significant way for tuning the bandgap and achieving broadband response, but the imperfection may renovate their intrinsic properties far from the desire. Here, by controlling the deviation from the perfection of the atomic lattice, ultrabroadband multilayer MoS2 photodetectors are originally designed and realized with the detection range over 2000 nm from 445 nm (blue) to 2717 nm (mid‐infrared). Associated with the narrow but nonzero bandgap and large photoresponsivity, the optimized deviation from the perfection of MoS2 samples is theoretically found and experimentally achieved aiming at the ultrabroadband photoresponse. By the photodetection characterization, the responsivity and detectivity of the present photodetectors are investigated in the wavelength range from 445 to 2717 nm with the maximum values of 50.7 mA W−1 and 1.55 × 109 Jones, respectively, which represent the most broadband MoS2 photodetectors. Based on the easy manipulation, low cost, large scale, and broadband photoresponse, this present detector has significant potential for the applications in optoelectronics and electronics in the future.
Ultrabroadband multilayer MoS2 photodetectors with the optical response up to 4.7 µm are designed and realized. Their detection properties, ranging from 445 nm (blue) to 2717 nm (mid‐infrared), are investigated at room temperature by controlling the S defects, which show the broadest detecting range with low‐cost fabrication process and have potential applications in many optoelectronic devices.
As one of the most prospective candidates for next-generation rechargeable batteries, lithium-sulfur (Li-S) batteries currently still encounter great challenges associated with the low conductivity, ...severe shuttle effects, and sluggish redox kinetics. Herein, a self-supported sulfur host is fabricated by an in-situ growth of MoO2/MoS2 nano-sheets on a carbon cloth (CC). First, carbon cloth serves as a good template for the morphology-controlled synthesis of nanostructured materials, which not only alleviates the agglomeration of MoO2/MoS2, but also enhances the flexibility and mechanical strengthen of the hybrid architecture as a free-standing host. Second, the polysulfide-trapping ability can be greatly enhanced by both physical and chemical adsorption from the MoO2/MoS2-anchored carbon cloth. Moreover, the partially sulfurized MoO2/MoS2 nano-sheets integrate the benefits of conductive MoO2 and sulfiphilic MoS2, thus facilitating fast charge transfer and redox kinetics of polysulfide conversion. As a result, these attributes enable the host to hold a high sulfur loading (up to 7.6 mg cm−2), which exceeds most of the reported carbon cloth-related cathode work in the literature. Additionally, the Li-S cells can achieve a high peak capacity of 1350 mA h g−1, excellent rate capability (C/20 - 2C rate), impressive areal capacity (up to 6.3 mA h cm−2), and a high capacity retention of 85% after 100 cycles.
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•Ni(OH)2/GS and Bi2O3/GS composite were synthesized respectively by simple methods.•A novel Ni/Bi battery is assembled using Ni(OH)2/GS and Bi2O3/GS as electrode materials.•The Ni/Bi battery exhibits ...a high capacity of 98mAhg−1 at 1C and energy density of 82.6Whkg−1.
Two kinds of graphene-based composite materials of Ni(OH)2 nanoparticles/graphene sheets (Ni(OH)2/GS) and Bi2O3 rods/graphene sheets (Bi2O3/GS) were respectively synthesized by chemical bath deposition. Morphological and structural analysis by field-emission scanning electron microscopy, transmission electron microscope, X-ray diffraction and X-ray photoelectron spectroscopy confirmed the successful composite of GS with the metal compounds. Then, a high performance Ni/Bi battery was designed and fabricated using the Bi2O3/GS hybrid material as negative electrode and Ni(OH)2/GS as positive electrode. As a result, this Ni/Bi battery delivers a high discharge capacity of 102mAhg−1 at 1C and good rate capability. A high energy density of 83.2Whkg−1 is also achieved at a power density of 143Wkg−1 and can still maintain a high level of 60.1Whkg−1 at 2609Wkg−1, illustrating that this Ni/Bi battery is a promising candidate as energy storage devices.
A gravitationally self-consistent, global sea level model with 3D viscoelastic Earth structure is interactively coupled to a 3D dynamic ice sheet model, and the coupled model is applied to simulate ...the evolution of ice cover, sea level changes, and solid Earth deformation over the last deglaciation, from 40 ka to the modern. The results show that incorporating lateral variations in Earth’s structure across Antarctica yields local differences in the modeled ice history and introduces significant uncertainty in estimates of both relative sea level change and modern crustal motions through the last deglaciation. An analysis indicates that the contribution of glacial isostatic adjustment to modern records of sea level change and solid Earth deformation in regions of Antarctica underlain by low mantle viscosity may be more sensitive to ice loading during the late Holocene than across the last deglaciation.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
It has been previously proposed that glacial inception represents a bifurcation transition between interglacial and glacial states and is governed by the nonlinear dynamics of the climate-cryosphere ...system. To trigger glacial inception, the orbital forcing (defined as the maximum of summer insolation at 65° N and determined by Earth's orbital parameters) must be lower than a critical level, which depends on the atmospheric CO.sub.2 concentration. While paleoclimatic data do not provide a strong constraint on the dependence between CO.sub.2 and critical insolation, its accurate estimation is of fundamental importance for predicting future glaciations and the effect that anthropogenic CO.sub.2 emissions might have on them. In this study, we use the novel Earth system model of intermediate complexity CLIMBER-X with interactive ice sheets to produce a new estimation of the critical insolation-CO.sub.2 relationship for triggering glacial inception. We perform a series of experiments in which different combinations of orbital forcing and atmospheric CO.sub.2 concentration are maintained constant in time. We analyze for which combinations of orbital forcing and CO.sub.2 glacial inception occurs and trace the critical relationship between them, separating conditions under which glacial inception is possible from those where glacial inception is not materialized. We also provide a theoretical foundation for the proposed critical insolation-CO.sub.2 relation. We find that the use of the maximum summer insolation at 65° N as a single metric for orbital forcing is adequate for tracing the glacial inception bifurcation. Moreover, we find that the temporal and spatial patterns of ice sheet growth during glacial inception are not always the same but depend on the critical insolation and CO.sub.2 level. The experiments evidence the fact that during glacial inception, ice sheets grow mostly in North America, and only under low CO.sub.2 conditions are ice sheets also formed over Scandinavia. The latter is associated with a weak Atlantic Meridional Overturning Circulation (AMOC) for low CO.sub.2 . We find that the strength of AMOC also affects the rate of ice sheet growth during glacial inception.
A 2D porous graphitic C3N4 nanosheets/nitrogen‐doped graphene/layered MoS2 ternary nanojunction is synthesized using a simple pyrolysis process followed by a hydrothermal treatment. The 2D ternary ...nanojunction exhibits significantly enhanced photoelectrochemical and photocatalytic activities due to the large contact area, efficient light absorption, and rapid charge separation and transport.
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