- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Homogeneous Anodic TiO <sub/>2</sub> Nanotube Layers on Ti–6Al–4V Alloy with Improved Adhesion Strength and Corrosion Resistance
摘要： Hexagonal TiO2 nanotubes (TNTs) arrays are generally fabricated on Ti-based substrates for some biomedical purposes, but the TNT layers constructed on conventionally processed Ti alloys are usually inhomogeneous because the substrates typically contain both the α and β phases. In this work, high-pressure torsion (HPT) is applied to obtain a saturated single α-phase microstructure in Ti–6Al–4V alloys via strain-induced β phase dissolution. Homogeneous anodic TNT layers with three different morphologies, one-step nanoporous, one-step nanotubular, and two-step nanoporous structures, are electrochemically fabricated on the ultrafine-grained (UFG) Ti–6Al–4V alloy substrates after HPT processing, whereas the TNT layers prepared on coarse-grained substrates are normally inhomogeneous. More notably, the TNT layers show significantly improved adhesion strength to the UFG substrate as well as better corrosion resistance compared to those on the conventionally processed Ti–6Al–4V substrates. X-ray diffraction analysis, scanning electron microscopy in combination with electron backscatter diffraction, and transmission electron microscopy indicate that the improvement is due to a larger dislocation density in the UFG substrate as well as strain-induced β phase dissolution.
关键词： high-pressure torsion,homogeneity,TiO2 nanotubes,adhesion strength,strain-induced phase transformation
更新于2025-11-21 11:03:13
-
Photodegradation of Fluoxetine Applying Different Photolytic Reactors: Evaluation of the Process Efficiency and Mechanism
摘要： Photolytic degradation of fluoxetine (FLX), a medicine commonly known as Prozac?, was evaluated by using different photochemical processes. The ultraviolet/microwave (UV/MW) process showed higher efficiency in all the aspects evaluated in this study. The energy consumption was equivalent to 1.94 × 10-4 kW h mg-1 L (UV/MW), while in the UV process the value was 1.20 × 10-2 kW h mg-1 L. The degradation kinetics were applied to the FLX, with rate constant (k) = 0.15 ± 0.01 min-1 and linear correlation coefficient (R2) = 0.980 for UV, and k = 6.15 ± 0.08 min-1 and R2 = 0.998 for UV/MW. The FLX degradation of 99.16% (UV/MW 5 min) and 98.90% (UV 120 min) were observed, evidencing higher efficiency for the first process. The monitoring of transformation products (TPs) through chromatographic analysis enabled the identification of 9 TPs, proving that for the UV/MW process, the hydroxylated structures are verified in high quantity.
关键词： photolysis,fluoxetine,transformation products,photochemical reactor,kinetics
更新于2025-11-19 16:56:35
-
Ultrasonication-assisted synthesis of CsPbBr <sub/>3</sub> and Cs <sub/>4</sub> PbBr <sub/>6</sub> perovskite nanocrystals and their reversible transformation
摘要： We demonstrate an ultrasonication-assisted synthesis without polar solvent of CsPbBr3 and Cs4PbBr6 perovskite nanocrystals (PNCs) and their reversible transformation. The as-prepared CsPbBr3 PNCs and Cs4PbBr6 PNCs exhibit different optical properties that depend on their morphology, size, and structure. The photoluminescence (PL) emission and quantum yield (QY) of the CsPbBr3 PNCs can be tuned by changing the ultrasound power, radiation time, and the height of the vibrating spear. The optimized CsPbBr3 PNCs show a good stability and high PL QY of up to 85%. In addition, the phase transformation between CsPbBr3 PNCs and Cs4PbBr6 PNCs can be obtained through varying the amount of oleylamine (OAm) and water. The mechanism of this transformation between the CsPbBr3 PNCs and Cs4PbBr6 PNCs and their morphology change are studied, involving ions equilibrium, anisotropic growth kinetics, and CsBr-stripping process.
关键词： ultrasonication,polar-solvent-free,CsPbBr3 PNCs,Cs4PbBr6 PNCs,reversible transformation
更新于2025-11-19 16:46:39
-
In-situ solid phase thermal transformation of self-assembled melamine phosphotungstates produce efficient visible light photocatalysts
摘要： Visible-light-driven stacked-layer heterogeneous photocatalyst carbonitride/tungstophosphate (TCN) was constructed via in-situ solid-state thermal transformation using melamine phosphotungstate (MPW). The structural, morphological and optical properties of the samples were investigated. Compared to the MPW hybrids and phosphotungstic acid hydrate, the TCN photocatalysts showed excellent visible light photocatalytic activity. During the thermal transformation, the melamine molecules polymerize to form the defective heptazine structure carbonitride attached to the surface of mixed-valence Keggin units. The interfacial POMs anions-p interactions, ligand-to-metal charge transfer and mix-valence organic-POMs structure makes the electrons fully delocalized over the MPW hybrids, and the TCN photocatalysts obtain the extended light absorption. The Keggin units accept and transfer electrons, so the recombination of photogenerated carriers is suppressed. 13TCN-390 obtains the optimal photocatalytic activity, its photocatalytic degradation efficiency of imidacloprid and rate constant k are 6.38 and 13.50 times than that of CN-390, respectively. The enhanced photocatalytic activity arises from the extended light absorption, suppressed photogenerated carriers’ recombination, surface structure defect and suitable band structure. h+ and (cid:1)OH are the main reactive species when the proposed photocatalytic mechanism was done. This study provides a promising construction strategy for polymer/POMs photocatalysts using different organic-POMs hybrids.
关键词： Melamine phosphotungstate,Visible-light-driven photocatalyst,Degradation,Thermal transformation
更新于2025-11-14 17:04:02
-
<p>A multifunctional-targeted nanoagent for dual-mode image-guided therapeutic effects on ovarian cancer cells</p>
摘要： Nanomedicine has emerged as a novel therapeutic modality for cancer treatment and diagnosis. Lipid–polymer hybrid nanoparticles (LPHNPs) are core–shell nanoparticle (NP) structures comprising polymer cores and lipid shells, which exhibit complementary characteristics of both polymeric NPs and liposomes. However, it is difficult to wrap perfluoropentane (PFP) into core–shell NPs in the existing preparation process, which limits its application in the integration of diagnosis and treatment. Methods: The folate-targeted LPHNPs-loaded indocyanine green/PFP-carrying oxygen (TOI_HNPs) using a combination of two-step method and solution evaporation technique for the first time. The essential properties and dual-mode imaging characteristics of developed NPs were determined. The cellular uptake of TOI_HNPs was detected by confocal microscopy and flow cytometry. The SKOV3 cell viability and apoptosis rate were evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay and flow cytometry. The ROS was demonstrated by fluorescence microplate reader and the expression of hypoxia-inducible factor 1-alpha (HIF-1α) and IL-6 was detected by Western blot. Results: TOI_HNPs showed spherical morphology with particle size about (166.83±5.54) nm and zeta potential at -(30.57±1.36) mV. It exhibited better stability than lipid NPs and higher encapsulation efficiency as well as active targeting ability than poly (lactic-co-glycolic acid) (PLGA) NPs. In addition, the novel NPs could also act as the contrast agents for ultrasound and photoacoustic imaging, providing precision guidance and monitoring. Furthermore, TOI_HNPs-mediated photo–sonodynamic therapy (PSDT) caused more serious cell damage and more obvious cell apoptosis, compared with other groups. The PSDT mediated by TOI_HNPs induced generation of intracellular ROS and downregulated the expression of HIF-1α and IL-6 in SKOV3 cells. Conclusion: This kind of multifunctional-targeted nanoagent may provide an ideal strategy for combination of high therapeutic efficacy and dual-mode imaging guidance.
关键词： core-shell nanoparticle,ultrasound,photo-sonodynamic therapy,phase transformation,photoacoustic imaging,laser
更新于2025-11-14 17:03:37
-
Study on heterogeneous photocatalytic ozonation degradation of ciprofloxacin by TiO2/carbon dots: Kinetic, mechanism and pathway investigation
摘要： In this study, the objective was mainly focusing on the mechanism investigation of ciprofloxacin (CIP) degradation by photocatalytic ozonation process which carried out by ozone and TiO2 with a low content of carbon-dots (CDs) under simulated sunlight irradiation. The physicochemical properties of the prepared photocatalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope (SEM) X-ray photoelectron spectroscopy (XPS) and zeta potential. Comprehensive investigation has proven the process to be efficient in the removal of CIP with high yield of reactive species (?OH, O2 ?—, h+, etc.). Kinetic model on pH investigation found out a repulsive force between the photocatalysts and CIP intensified with the increasing pH, so did the production rate of hydroxyl radicals (?OH), while eventually reached a balance and achieved a maximum degradation rate. The results indicated that the enhancement mechanism was triggered by the photoexcited electron accumulated on CDs and transferred by ozone, resulting in the continuous generation of h+, O3 ? — and O2 ? —. Possible photocatalytic ozonation degradation pathways of CIP were proposed according to the identifications of intermediates using high-resolution accurate-mass spectrometry (HRAM) LC-MS/MS.
关键词： ciprofloxacin,reactive species,carbon-dots,photocatalytic ozonation,transformation pathway
更新于2025-11-14 15:15:56
-
One-Dimensional Mercury Halide Coordination Polymers Based on A Semi-Rigid N-Donor Ligand: Reversible Structural Transformation
摘要： Four one-dimensional (1D) mercury(II) halide coordination polymers have been synthesized by using a semi-rigid N-donor ligand, 2,2′-(1,4-phenylene)-bis(N-(pyridin-3-yl)acetamide) (1,4-pbpa). While [Hg(1,4-pbpa)Cl2·CH3OH]n, 1, forms a sinusoidal chain, the complexes [Hg(1,4-pbpa)X2]n (X = Cl, 2; Br, 3; I, 4) are helical. The sinusoidal 1 undergoes reversible structural transformation with helical 2 upon removal and uptake of CH3OH, which was accompanied with the conformation adjustment of the 1,4-pbpa ligand from trans anti-anti to trans syn-anti. Pyridyl ring rotation of the 1,4-pbpa ligand that results in the change of the ligand conformation is proposed for the initiation of the structural transformation.
关键词： mercury halide,structural transformation,bis-pyridyl-bis-amide,coordination polymer
更新于2025-11-14 15:13:28
-
Performance Assessment of High Resolution Airborne Full Waveform LiDAR for Shallow River Bathymetry
摘要： We evaluate the performance of full waveform LiDAR decomposition algorithms with a high-resolution single band airborne LiDAR bathymetry system in shallow rivers. A continuous wavelet transformation (CWT) is proposed and applied in two fluvial environments, and the results are compared to existing echo retrieval methods. LiDAR water depths are also compared to independent field measurements. In both clear and turbid water, the CWT algorithm outperforms the other methods if only green LiDAR observations are available. However, both the definition of the water surface, and the turbidity of the water significantly influence the performance of the LiDAR bathymetry observations. The results suggest that there is no single best full waveform processing algorithm for all bathymetric situations. Overall, the optimal processing strategies resulted in a determination of water depths with a 6 cm mean at 14 cm standard deviation for clear water, and a 16 cm mean and 27 cm standard deviation in more turbid water.
关键词： bathymetry,full waveform,wavelet transformation,LiDAR
更新于2025-09-23 15:23:52
-
Degradation of tetracycline by medium pressure UV-activated peroxymonosulfate process: Influencing factors, degradation pathways, and toxicity evaluation
摘要： This study employed the medium pressure UV/peroxymonosulfate (MPUV/PMS), a new sulfate radical-based advanced oxidation process, to eliminate tetracycline (TTC) in water. At pH = 3.7, initial TTC concentration of 11.25 μM, PMS dosage of 0.2 mM and UV dose of 250 mJ cm-2, 82 % of TTC was degraded by MPUV/PMS. The second-order reaction rate constants of TTC with SO4?- and ?OH were found to be 1.4 × 1010 M-1 s-1 and 6.0 × 109 M-1 s-1, respectively. Radical quenching experiments indicated that ?OH played the major role in the degradation of TTC. Higher PMS dosage (0.1 mM~1.0 mM) and higher pH (3~11) could accelerate the TTC removal. Besides, the presence of Cl- (0.1 mM~5.0 mM) and CO32- (0.05 mM~0.5 mM) could also promote the reaction. Eight transformation products (TPs) were identified, and the potential degradation pathways mainly involved hydroxylation, demethylation and decarbonylation processes. The variation in the genotoxicity was investigated using the umu-test, and the results indicate that the genotoxicity of TTC after the MPUV/PMS treatment significantly increased during the initial stage. In addition, the ecotoxicity and mutagenicity of TTC and its TPs were predicted using quantitative structure-activity relationship (QSAR) analysis, and the results revealed that some TPs could have equivalent and even higher toxicity than TTC. MPUV/PMS showed better performance in TTC degradation in real waters than in Milli-Q water. MPUV/PMS is concluded to be an efficient method for removing TTC, but more attention should be paid to the changes of toxicity during this process.
关键词： Tetracycline,Toxicity,Hydroxyl radical,Sulfate radical,Transformation products
更新于2025-09-23 15:23:52
-
Communicating the spatiotemporal transformation of architectural heritage via an in-situ projection mapping installation
摘要： Understanding the spatial transformation of architectural heritage over time is crucial for documentation and conservation purposes, but also for communicating the salient architectural features of the buildings’ evolution to the public at large. With the rapid evolution of physical computing technologies such as electronics, sensors and digital projections, we believe that the technique of projection mapping offers great potential in communicating heritage in-situ because its graphical depiction on the heritage itself can more directly relate to the real context in more experiential ways. Furthermore, digital projections can include various interactive functionalities that together with its architectural size provide an immersive experience that is dynamic and adaptable to the interests of the visitors. Consequently, this paper aims to investigate the deployment of an interactive projection mapping installation in-situ which can be steered by a tangible user interface (TUI). Through an in-the-wild study, we deployed a mixed-method evaluation to investigate how such an interactive projection mapping enhances the communication of the spatiotemporal transformation of a medieval chapel that occurred during the last 850 years. Our findings show how the in-situ projection positively affects visitors’ understanding and memorability of the aesthetic features, and how its combination with a tangible interface enhances the communication of the spatial features of the chapel over time, and allows for more social interaction among them. The paper concludes with several discussion points and recommendations for applying interactive projection mapping and TUIs in the context of architectural heritage.
关键词： Spatiotemporal transformation,Tangible user interface (TUI),Heritage communication,Architectural heritage,Projection mapping,In-situ installation
更新于2025-09-23 15:23:52