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•Explores MOFs for hydrogen storage, covering physical adsorption and chemical methods.•Pore structures, packing densities and metal sites codetermine MOFs’ physical ...storage.•Computational techniques have streamlined MOFs' physical hydrogen storage enhancement.•MOFs as heterogeneous catalysts and confined frameworks for chemical hydrogen storage.
Exceptionally porous crystals with ultrahigh adsorption capacities, metal–organic frameworks (MOFs), have received recognition as leading candidates for the promotion of solid-state hydrogen storage. MOFs are compelling adsorbents given their impressive uptake under stringent cryogenic and high-pressure conditions for physisorption. The use of high-throughput screening to rapidly identify potential candidates, the understanding of structure–property correlations through molecular simulations, and the use of machine learning to predict material properties offer a more efficient approach to meeting these stringent operational constraints. Furthermore, the open metal sites and customizable pore structures act make MOFs as catalysts or nanoconfinement matrices, facilitating enhancements in the thermodynamics and kinetics of reactive chemical hydrides. Strategically harnessing the tunability of MOFs could unlock vast, untapped potential for enabling high-density, reversible hydrogen storage under real-world conditions, aligned with sustainability needs. This review establishes MOFs as an innovative platform in solid-state hydrogen storage by intertwining material discovery with engineering principles. The comprehensive analysis and consolidation of the research provides new perspectives to broaden the scope of the investigation and drive the widespread deployment and development of hydrogen energy.
The evolution of writing systems illustrates the development of information storage. Here, a unique way is demonstrated using sprayed anisole as the ink and a focused electron‐beam as a pen to record ...messages on a cooled substrate. Such an electron‐beam writing approach controls the thickness of remained anisole on the substrate. Optical interference at the visible region occurs thereby, resulting directly in a color print. Using discrete dose distribution, an 11‐step structure with a height difference of sub‐10 nm accuracy is written. A quinary pattern with a total thickness of 180 nm and unit square size of 500 nm is also written, implying information density beyond 1013 bits per cm3 (10 Tbit cm–3). Painting at the nanoscale is also enabled by importing grayscale images. In addition, the substrate can be extended from planar to nonplanar or flexible objects, such as an aluminum tape or a silver wire. Combining the grayscale lithographic nature and conformal coating of the ink, this writing process has great potential to store information on any surface.
Benefiting from 3D grayscale lithography and conformal covering of sprayed “organic ink,” stepped structures with an accuracy of sub‐10 nm in height are written by using a focused electron‐beam as a pen, leading to information storage or high‐resolution painting on nonplanar objects.
To understand the impact factors of the re-emergence of Oncomelania snails in hardened ditches so as to find out the measures to improve the effect of snail eradication.
Thirteen infected townships ...from Jingmen City were randomly selected and investigated with the retrospective method and the field survey. All the data were analyzed for evaluating the effect of the hardened ditches on snail eradication and finding out the causes of the re-emergence of snails in hardened ditches
After on-site investigation of 151 hardened ditches, the eradication rate of snail areas was 78.79%, and 71 ditches were founded with snails and the re-emergence rate was 47.02%. The major factors of the snail re-emergence were the spread of the snails from the upstream, the dilapidation of the hardened ditches, no using molluscicides before the hardened ditches, and the snails being brought by the engineering construction.
The only hardened ditches can not eradicate the snails. We should manage an overall plan when processing the ditc
A low-profile transmitarray lens design is presented at X-band, which is composed of only one layer of substrate with thickness of 0.13 free-space wavelengths. The transmitted unit cell utilises ...structure of two metallic layers and four via holes, broadening the transmitted phase shift range to more than 310° while transmission magnitude is within −3 dB under normal incidence. A prototype of the transmitarray lens with aperture size of 280 mm is designed, simulated and measured. Measurement and simulation results agree well with each other and gain of 23.9 dBi is obtained at 10 GHz; the proposed low-profile transmitarray lens antenna could be applied to practical X-band radar systems with low cost and convenience.
In this paper, a kind of dynamically tunable graphene metasurface which can act as a multi-band refractive index sensor or a four-state optical switch is proposed. Based on the plasmonic ...hybridization mechanism of a simple graphene ring array, this design exhibits dual-channel resonance modes to realize ultrahigh sensitivity for refractive index sensing, which is 4.25μm/RIU at mid-infrared band and 11.33μm/RIU at far-infrared band, respectively. The proposed design manifests an ultrabroad sensing range through tuning the Fermi level of graphene and a good insensitivity to the incident angle. In addition, we numerically demonstrate a reflective optical switch with the structure of dual-layer graphene disks which indicates that a four-state optical switch is achieved and the cut-off absorptivity is more than 98%. The concise structures are of high feasibility for fabrication and the results illustrate considerable potential in various applications including graphene optics and integrated photonic systems.
•Concise and dynamically tunable graphene metasurface for multi-band sensing is proposed.•Ultrahigh sensitivity of 4.25/11.33μm/RIU at mid-/far-infrared band is obtained.•Ultrabroad dynamic range and good insensitivity to incident angle are presented.•Four-state switch exhibits high cut-off absorptivity more than 98%.
We study the temperature effects of the vibrational frequency, the ground state energy and the ground state binding energy of the strong-coupling magnetopolaron in an anisotropic quantum dot. The ...vibrational frequency, the ground state energy and the ground state binding energy are expressed as functions of the temperature, the cyclotron frequency of a magnetic field and the electron-phonon coupling strength by using linear combination operator and unitary transformation methods. It is found that these quantities will increase with increasing temperature and cyclotron frequency of a magnetic field. The vibrational frequency and the ground state binding energy are increasing functions of the electron-phonon coupling strength, whereas the ground state energy is an decreasing one of it.
Ice lithography (IL) enables in-situ nanofabrication by electron-beam patterning and subsequent pattern transfer of water ice deposited on cryogenic samples. Here we report the design and operation ...of an IL instrument consisting of a scanning electron microscope, a gas injection system, cryogenic components, a metal deposition chamber, and a sample transfer assembly. The steps required and the amount of equipments involved are significantly reduced compared with ordinary electron beam lithography methods. Different from the previous apparatus, thermal evaporation and internal cooling were implemented and evaluated in this instrument. The in-situ nanofabrication is demonstrated by decorating nanoparticles on or close to a single nanowire and constructing three-dimensional layered structures. Finally, we present an outlook on the further improvement of our instrument.
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•Design, implementation and evaluation of advanced ice lithography instrument.•In-situ alignment and high-resolution e-beam lithography with water ice.•3D nanofabrication through a streamlined process.
•A novel Ti-MOF adsorbent was synthesized by solvothermal method.•Ti-MOF-SH has excellent selectivity and reproducibility for Hg(Ⅱ) and Pb(Ⅱ).•The adsorption mechanism of Ti-MOF-SH is chelation and ...electrostatic interaction.•The adsorption effect of Ti-MOF-SH on Hg(Ⅱ) is better than that of Pb(Ⅱ).•The adsorption process of Hg(Ⅱ) and Pb(Ⅱ) accords with Langmuir adsorption isothermal model.
Herein, Ti-MOF-SH was sucessfully synthesized by a simple one-step method. The kinetics, capacities, selectivities, repeatabilities and mechanisms of Hg2+ and Pb2+ absorption and removal by Ti-MOF-SH have been investiged. Batch experiments show that the maximum adsorption capacity of Ti-MOF-SH for Hg2+ and Pb2+ is 943 and 341 mg/g (298 K), respectively, under the optimum pH (5.0). The adsorption process is endothermic, which conforms to the pseudo-second-order kinetic model and Langmuir model, and mainly depends on electrostatic interaction and the chelation of functional groups containing S and O with metal ions. In addition, Ti-MOF-SH has excellent selectivity and repeatability for Hg2+ and Pb2+, which is expected to be widely used in the future. The above conclusion indicate that Ti-MOF-SH has excellent comprehensive performance for Hg/Pb removal and is expected to be widely applied in industrial engineering.
Three different types of polarization-sensitive perfect absorbers are designed and numerically investigated. The bottle-like and the cup-like absorbers are narrowband absorbers, which strongly absorb ...light of a specific polarization and reflect almost all light of another polarization. By varying the geometric parameters, their absorption peaks can be tuned from 1300 nm to 2300 nm and 700 nm to 1400 nm, respectively. The broadband absorber is polarization-sensitive as well, exhibiting an average absorption efficiency of 88% over a wide range of wavelength (700-2300 nm). The proposed absorbers may have potential applications in polarization detectors, polarizers etc.
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