- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Graphdiyne: A promising nonlinear optical material modulated by tetrahedral alkali-metal nitrides
摘要： A new series of the functionalized graphdiyne (GDY) material was designed by adsorbing the tetrahedral Li3NM molecules on the largely delocalized π-conjugated GDY surface, namely Li3NM@GDY (M = Li, Na, K), and its structure, chemical stability, electronic property, and the first hyperpolarizability were investigated by using the density functional theory computations. Our results reveal that the Li3NM molecules can interact with three triangular holes on the GDY surface, in which the van der Waals interactions play a crucial role in enhancing the structural stability. Meanwhile, the total NPA charges on the Li3NM molecules are gradually increased from Li to K, and the Li3NM molecules can transfer an electron to GDY, forming intramolecular electron donor and acceptor pairs. All of studied complexes exhibit the giant static first hyperpolarizabilities (βtot), up to ~2.88 × 105 a.u. for Li3NK@GDY, which can be explained by two-level expression from the TDDFT calculations. This study will inevitably stimulate further synthesis of the novel graphdiyne-based nonlinear optical materials.
关键词： Graphdiyne,Electronic structure,TDDFT,Charge transfer,Nonlinear optical property
更新于2025-09-23 15:23:52
-
Optical-property coefficient estimation of bulky medium in experiments with a succinctly analytical calculation
摘要： Diffuse optical imaging enables to reconstruct distribution of optical properties, absorption and scattering coefficients, in tissue for breast cancer detection based on diffusion equation with the help of the initial guess obtained from measured data. To estimate the initial guess of the optical-property coefficients, an analytical solution of diffusion equation can be used and compared with the measured data. The analytical solution for a homogeneous infinite medium can be obtained in the frequency domain, expressing that the photon intensity and the phase lag relative to the distance between source and detector in a linear relationship. In this study, a succinct calculation using the trigonometric relation is proposed to estimate the optical-property coefficients. A tank-type and a cylinder Lipovenoes phantoms with two concentrations of 1.25% and 2.5% are employed and measured for verification. It is found that the method proposed here shows better results and results in estimation errors of 0–14.81% for μa and 20–42% for μs′.
关键词： Diffusion equation,Photo-density wave experiment,Optical-property coefficients
更新于2025-09-23 15:23:52
-
Surface functionalization of titanium with zinc/strontium-doped titanium dioxide microporous coating via microarc oxidation
摘要： Deficient osseointegration and implant-related infections are pivotal issues for the long-term clinical success of titanium (Ti) implants. Zinc (Zn) and strontium (Sr) serve dual functions by promoting osteogenesis and inhibiting bone destruction, and Zn has good antibacterial activity. As such, this study examined the preparation of a Zn/Sr-doped titanium dioxide microporous coating (MT-Zn/Sr) on a Ti surface using microarc oxidation (MAO), with Zn and Sr evenly distributed throughout the coating. In vitro, the coating could promote the adhesion, proliferation, differentiation and mineralization of osteoblasts, showing good biological activity. Antibacterial testing demonstrated the good antibacterial activity of the coating, as it inhibited the proliferation of Staphylococcus. In vivo, MT-Zn/Sr promoted early osseointegration between the Ti substrate and the bone tissue. This work is expected to provide a new method for improving the biological activity of Ti implants and thus has important theoretical significance and great clinical prospects.
关键词： Osseointegration,Strontium,Zinc,Titanium coating,Antibacterial property
更新于2025-09-23 15:23:52
-
Data-driven and probabilistic learning of the process-structure-property relationship in solution-grown tellurene for optimized nanomanufacturing of high-performance nanoelectronics
摘要： Two-dimensional (2-D) semiconductors have been intensely explored as alternative channel materials for future generation ultra-scaled transistor technology [1–8]. However, significant roadblocks (e.g., poor carrier mobilities [9–11], instability [4,5,10], and vague potential in scaling-up [10,12–15]) exist that prevent the realization of the current state-of-the-art 2-D materials’ potential for energy-efficient electronics. The emergent solution-grown tellurene exhibits attractive attributes, e.g., high room-temperature mobility, large on-state current density, air-stability, and tunable material properties through a low-cost, scalable process, to tackle these challenges [16]. Nevertheless, the fundamental manufacturing science of the hydrothermal processing for tellurene remains elusive. Here, we report on the first systematic, data-driven learning of the process-structure-property relationship in solution-grown tellurene, revealing the process factors’ effects on tellurene’s production yield, dimensions, and transistor-relevant properties, through a holistic approach integrating both the experimental explorations and data analytics. We further demonstrate the application of such fundamental knowledge for developing tellurene transistors with optimized and reliable performance, which can enable the cost-effective realization of high-speed, energy-efficient electronics.
关键词： Process-structure-property relationship,2-D materials,Energy-efficient electronics,Nanomanufacturing,Tellurene,Data-driven learning
更新于2025-09-23 15:23:52
-
Asymmetric Diarylethenes with Oxidized 2-Alkylbenzothiophen-3-yl Units: Chemistry, Fluorescence, and Photoswitching
摘要： Reversibly photoswitchable diarylethenes (DAEs) with fluorescent closed forms are applied in biology- and material science-related super-resolution microscopy. Yet, their full photoswitchable capacities remain unrevealed and unexplored. Due to limitations in synthesis, only 1,2-[bis-(2-ethyl-1-benzothiophene-1,1-dioxide-3-yl)]perfluorocyclopentenes with two identical or very similar aryl groups attached to C-6 and C-6′ have been prepared so far. DAEs with increased Stokes shifts related to asymmetric structures and the presence of 'push–pull' substituents are introduced in the present study, and their switching power is studied. The new 'simplified' asymmetric DAEs possess higher cycloreversion quantum yields, but lower emission efficiencies than their known analogs with extended π-conjugation paths. Fatigue resistance in organic (acetonitrile and methanol) and aqueous solvents is studied, and the performance in reversible saturable optical fluorescence transition (RESOLFT) microscopy is evaluated. The push–pull structures show an outstanding increase in fatigue resistance, compared with a reference (H/H) diarylethene. Fatigue resistances on the order of thousands of cycles have been observed in acetonitrile solutions without exclusion of air oxygen. The structure–property relationships and facile preparation procedures enable rational design of DAEs applicable as photoswitchable fluorescent probes. A new setup and methodology for measuring switching performance of fluorescent DAEs are introduced.
关键词： photoluminescence,photonics,photochemistry,structure–property relationships
更新于2025-09-23 15:23:52
-
Dielectric property of modified barium titanate/polyamide 11 nanocomposites with different surfactants
摘要： Barium titanate/polyamide 11 (BT/PA11) nanocomposites were prepared by modifying BT nanoparticles with dry surface modification process, which had well dispersion, high dielectric constant, and low dielectric loss. Various methods were reported to improve dispersion and compatibility with complex process and high cost. Herein, three surfactants [γ-aminopropyl triethoxy silane (KH550), sorbitan monostearate (SP60), and octadecyl phosphate ester (OPE)] were chosen to modify BT nanoparticles. Then modified-BT nanoparticles were blended with PA11. The structure was characterized by Fourier transform infrared, scanning electron microscope, and wide angle X-ray diffraction. Dielectric property was studied by broadband dielectric spectroscopy. The frequency dependence and temperature dependence of dielectric constant, dielectric loss, and dielectric modulus were analyzed. In general, dielectric property has strong frequency and temperature dependence. Furthermore, dielectric spectra shows that modified BT/PA11 nanocomposites have higher dielectric constant, lower dielectric loss, fewer interface polarization, and more dipole polarization. In contrast to three surfactants, OPE-BT nanoparticles have better effects, whose dielectric constant increases from 19 to 28 at 1 Hz, and dielectric loss decreases from 0.36 to 0.23. Meanwhile, mechanical property was characterized by universal testing machine. In all, the work improves dispersion of BT nanoparticles and dielectric property with easy process and low cost. ? 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47447.
关键词： BT/PA11 nanocomposites,dielectric property,modification,surfactants
更新于2025-09-23 15:23:52
-
Polymeric fluorescent film sensor based on poly(azomethine-urethane): Ion sensing and surface properties
摘要： A polymeric film sensor containing poly(azomethine-urethane) was easily fabricated using the dip-coating technique and ion sensing property of this film toward different metal cations investigated. Fluorescence measurements showed that fluorescent film sensor has been exhibited dual emission wavelengths at 540 and 582 nm and metal cation sensing behavior of this film studied using these two wavelengths. Also, fluorescent film sensor was showed selectivity and sensitivity toward iron (III) ions in deionized water with excellent photostability. The detection limit of the polymeric sensor was found as 86.15 and 28.90 μM at these wavelengths. The results indicated that chemosensor can be successfully applied for the detection of iron (III) ions in deionized water. Contact angle measurements of the film probe were also evaluated to investigate the surface hydrophilicity or hydrophobicity of the film.
关键词： Poly(azomethine-urethane),Fe (III) sensor,Film sensor,Surface property
更新于2025-09-23 15:23:52
-
Fluorine modification on titanium dioxide particles: Improving the anti-icing performance through a very hydrophobic surface
摘要： In this study, fluorine modification was successfully conducted on titanium dioxide (TiO2) to enhance the anti-icing property through fabricating a very hydrophobic surface. TiO2 was firstly modified with 3-methacryloxypropyl-trimethoxysilane (MPS) to introduce C=C bonds. Then, dodecafluoroheptyl methacrylate (DFHMA) monomers were successfully grafted on the TiO2 particles via C=C bonds introduced by MPS. Herein, azobisisobutyronitrile (AIBN) was used as initiator to initiate the reaction. The chemical components of the TiO2 particles were investigated by X-ray photoelectron spectroscopy (XPS). XPS analysis of fluorine-modified TiO2 revealed that the fluorine content reached a peak value of 7.3%, while the water contact angle enhanced to a maximum value of 146o. This water contact angle value of 146o was dramatically increased by 131o in comparison with unmodified TiO2, indicating a very hydrophobic surface. The crystallization temperature of a water droplet on the corresponding fluorine-modified TiO2 decreased to -19.4 oC (10.3 oC decrease in comparison with that of a water droplet on unmodified TiO2). Also, the freezing delay time on the fluorine-modified TiO2 is more than 25 min under the testing temperature of -10 oC, exhibiting excellent anti-icing property.
关键词： Azobisisobutyronitrile,Fluorine modification,Anti-icing property,Dodecafluoroheptyl methacrylate,Titanium dioxide
更新于2025-09-23 15:23:52
-
First-principles study of the electronic structure and optical properties of Eu2+–M (M = Mn2+, Mg2+, Li+) co-doped γ-AlON phosphor
摘要： In our recent work we found γ-AlON:Eu2+ phosphors to hold promise for application in white light-emitting diodes (LEDs). To obtain further insight into Eu2+–M (M = Mn2+, Mg2+, Li+) co-doped γ-AlON, the crystal structure and the electronic and photoluminescence properties of γ-AlON:Eu2+–M (M = Mn2+, Mg2+, Li+) phosphors were studied using first-principle calculations under the framework of density functional theory. Based on the experimental and calculated results, the structure of Eu2+–M (M = Mn2+, Mg2+, Li+) co-doped γ-AlON was established. The calculated results demonstrate that Eu2+ and M (= Mn2+, Mg2+, Li+) can effectively improve the absorption of ultraviolet light by γ-AlON:Eu2+. The absorption coefficient of AlON:Eu2+–Li+ in the ultraviolet blue region of 275–415 nm reached 67,266 cm–1, and the absorption coefficients of AlON:Eu2+–Mn2+ and AlON: Eu2+–Mg2+ at the same doping concentration were 51,219 and 60,575 cm–1, respectively. Our calculations therefore show that the performance of AlON:Eu2+–Li+ is better than AlON:Eu2+–M (M = Mn2+, Mg2+).
关键词： γ-AlON,First principles,Electronic structure,Optical property
更新于2025-09-23 15:23:52
-
Cobalt doping-induced strong electromagnetic wave absorption in SiC nanowires
摘要： Understanding the electronic structure-property relationship in doped systems is a prerequisite to designing functional materials. We fabricated Co-doped SiC nanowires with different Co contents by a facile carbothermal reduction approach. The nanowires were characterized in terms of microstructure, electronic structure, and electromagnetic (EM) parameters to uncover the effect of Co dopants on enhancing the EM wave absorption ability. Microstructure analysis and density functional theory calculations verified that the doped Co species inhibited the formation of stacking faults and point defects and increased the conductivity of Co-doped SiC nanowires, which indicated the dominant role of conductivity in enhancing dielectric loss. The Co dopants also imparted the Co-doped SiC nanowires with distinct room-temperature ferromagnetic property, which led to enhanced magnetic loss and impedance matching. The induced synergism among SiC nanowires and Co dopants endowed Co-doped SiC nanowires with strong EM wave absorption ability. The minimum reflection loss of Co-doped SiC nanowires reaches (cid:1)50 dB, and the effective absorption bandwidth is 4.0 GHz with only 1.5 mm sample thickness. Thus, Co-doped SiC nanowires can be used as effective EM wave absorption materials. This study also provided a guideline for designing high-performance EM wave absorbers.
关键词： Dielectric loss,Doping,Density functional theory calculations,Electromagnetic wave absorption,Magnetic property
更新于2025-09-23 15:23:52