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1.
Langmuir ; 39(51): 18935-18945, 2023 Dec 26.
Artículo en Inglés | MEDLINE | ID: mdl-38096809

RESUMEN

The design of nanocomposites as a light-capturing system applied in photocatalytic water splitting is an emerging area of research. In our study, a simple in situ photodeposition method was proposed for the synthesis of CdS nanoflowers modified by nickel-based bifunctional, i.e., Ni/Ni(OH)2, cocatalysts. The introduction of cocatalysts has demonstrated a notable enhancement in the photocatalytic hydrogen evolution efficiency of CdS. The quantity of cocatalysts supported on CdS played an important role in governing the light absorption capability and photocatalytic efficacy. Ni-CdS-10 showed the best photocatalytic activity of 30.51 mmol g-1 h-1, which was 1.8 times and 2.6 times higher activity than Pt-CdS-1 wt % and pure CdS, respectively. Mechanism studies with UV-vis DRS, photoluminescence, and Mott-Schottky plots revealed the intrinsic electric field created at the p-n Ni(OH)2/CdS junctions, which can effectively implement the transport and separation of photoinduced carriers. From linear sweep voltammetry, electrochemical impedance spectroscopy, and DFT calculation, both Ni(OH)2 and Ni can effectively decrease the Gibbs free energies of hydrogen adsorption and reduce the overpotential of hydrogen evolution. As a result, the efficiency of generating H2 through photocatalysis experienced significant improvement, and the participation of bifunctional cocatalysts further reduced the photocorrosion of CdS, enhanced stability, improved low price, and efficient photocatalyst production.

2.
Sensors (Basel) ; 22(11)2022 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-35684826

RESUMEN

Event detection is an important task in the field of natural language processing, which aims to detect trigger words in a sentence and classify them into specific event types. Event detection tasks suffer from data sparsity and event instances imbalance problems in small-scale datasets. For this reason, the correlation information of event types can be used to alleviate the above problems. In this paper, we design a Hierarchical Attention Neural Network for Event Types (HANN-ET). Specifically, we select Long Short-Term Memory (LSTM) as the semantic encoder and utilize dynamic multi-pooling and the Graph Attention Network (GAT) to enrich the sentence feature. Meanwhile, we build several upper-level event type modules and employ a weighted attention aggregation mechanism to integrate these modules to obtain the correlation event type information. Each upper-level module is completed by a Neural Module Network (NMNs), event types within the same upper-level module can share information, and an attention aggregation mechanism can provide effective bias scores for the trigger word classifier. We conduct extensive experiments on the ACE2005 and the MAVEN datasets, and the results show that our approach outperforms previous state-of-the-art methods and achieves the competitive F1 scores of 78.9% on the ACE2005 dataset and 68.8% on the MAVEN dataset.


Asunto(s)
Procesamiento de Lenguaje Natural , Redes Neurales de la Computación , Lenguaje , Memoria a Largo Plazo , Semántica
3.
Phys Chem Chem Phys ; 21(3): 1606-1613, 2019 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-30620022

RESUMEN

In this paper, vanadium carbides VC2 and bi-transition-metal carbides V1/2Mn1/2C2 are predicted to be stable metallic nanosheets showing promising mechanical properties and their Young's moduli are 70.8 N m-1 and 83.7 N m-1, respectively. Ab initio molecular dynamics results showed that both VC2 and V1/2Mn1/2C2 can tolerate temperatures up to 1000 K showing favorable thermal properties. The excellent Li-ion specific energy storage capacity and low diffusion barrier also make them promising candidates as anode materials. In addition, nonmagnetic-ferromagnetic (-ferrimagnetic) transitions in VC2 and V1/2Mn1/2C2 can be tuned easily by oxygen or fluorine passivation.

4.
Phys Chem Chem Phys ; 20(39): 25437-25445, 2018 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-30272085

RESUMEN

In this paper, manganese carbide (MnC) and niobium carbide (NbC) are predicted as stable monolayer metallic materials, whose Young's moduli are 50.06 N m-1 and 44.07 N m-1, respectively. The ab initio molecular dynamics (AIMD) results show that both MnC and NbC could hold their structure up to 1000 K, showing favorable thermal properties. These monolayers also show good properties for promising application in Li ion batteries because of their high specific capacities and low diffusion barriers. The MnC monolayer is ferromagnetic and the Curie temperature simulated by the Monte-Carlo method is about 205 K. The electronic band of MnC shows a metal to half-metal transition by passivation of Cl or Br atoms, and the functionalization methods also cause the metallic NbC monolayer to exhibit the quantum spin Hall effect (QSHE). These novel transition metal carbide monolayers hold great promise for 2D spintronic and electronic device applications.

5.
Phys Chem Chem Phys ; 19(23): 15394-15402, 2017 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-28580468

RESUMEN

Herein, two-dimensional materials for photocatalytic water splitting are drawing more attention due to the larger surface areas for photocatalytic reactions and shorter migration distances for photogenerated carriers. In this present study, we systematically investigated the fundamental electronic properties of GaS1-xTex monolayers (x = 0, 0.125, 0.25, 0.5, 0.75, 0.875, and 1) for water splitting based on density functional theory (DFT) using the HSE06 functional. The simulation of the defect formation energy under each experimental synthetic condition shows that the Te substitutional impurity in GaS can be relatively easily realized under Ga-rich conditions. Our results show that the GaS0.5Te0.5 monolayer is a direct band gap (2.09 eV) semiconductor, which is attributed to the elevation of Te px/py states at the Γ point by the strain effect. Moreover, the GaS0.5Te0.5 monolayer has appropriate band edge alignment with respect to the water redox potentials in both acidic and neutral environments. Additionally, the carrier effective mass of the GaS0.5Te0.5 monolayer along the direction of Γ â†’ K is smaller than those of pristine GaS and GaTe monolayers, which can cause the carriers to quickly transfer from the photogenerated center to the surface of the photocatalyst. These results imply that the GaS0.5Te0.5 monolayer is a promising candidate as a visible-light water splitting photocatalyst, which should be properly synthesized and tested in further experimental investigations.

6.
Phys Chem Chem Phys ; 16(33): 17705-14, 2014 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-25031088

RESUMEN

The mechanism for the decreasing critical temperature (T(C)) of the metal-insulator transition (MIT) in vanadium dioxide (VO2) by tungsten (W) doping is a matter of debate. Here, to clarify the correlation between W doping and T(C), the electronic and geometrical structures around W and V atoms in W(x)V(1-x)O2 samples are systematically investigated by X-ray absorption fine structure (XAFS) spectroscopy. The evidence of electron doping of W(6+) ions in VO2 is obtained from the reduction of V(4+) to V(3+) ions. This kind of electron doping has been considered to favor the MIT process. Moreover, from the XAFS results, the local rutile structure around W dopants is identified even at low doping, and acts as the structure-guided domain to facilitate the MIT in VO2. Considering the electronic band structures of W(x)V(1-x)O2 samples, the internal stresses induced by W(6+) doping yield the detwisting of the nearby monoclinic VO2 lattice. This lattice detwisting will drive the downward shift of the π* electron band and a smaller separation between antibonding and bonding d∥ orbitals in the band structure of VO2, which induces the decreased band gaps of W(x)V(1-x)O2 samples. As a consequence, the potential energy barrier for phase transition is lowered and the reduced T(C) is observed.

7.
JMIR Form Res ; 8: e58330, 2024 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-39186763

RESUMEN

BACKGROUND: Stroke is the leading cause of acquired disability and the second leading cause of death worldwide. Its rate of incidence, disability, mortality, and recurrence is high, and the patients experience various symptoms of discomfort, which not only affect their rehabilitation function but also reduce their ability to perform daily activities and their quality of life. Nowadays, with the improvement of China's medical standards, patients are increasingly attentive to their quality of life and health status. However, diagnostic techniques and effective treatments for patients with stroke are still limited but urgently required. OBJECTIVE: This study aimed to evaluate the quality of life during hospitalization using a stroke patient-reported outcomes (PROs) scale and additionally to recognize potential factors and risk indicators that may impact recurrent events, facilitating early intervention measures. METHODS: This is a registry-based, retrospective observational cross-sectional study on patients with stroke. A convenient sampling method was used to select various indicators of patients. The Stroke-PRO scale was then used to assess patients' conditions across physical, psychological, social, and therapeutic domains. Multiple linear regression analysis was applied to identify factors influencing stroke PROs, while correlation analysis was conducted to explore the relationship between these outcomes and blood lipid levels. RESULTS: The mean Stroke-PRO score in this study was 4.09 (SD 0.29) points. By multiple linear regression analysis, residence, occupation, physical exercise, Barthel index, Braden scale, National Institutes of Health Stroke Scale scores at admission, and stroke type were the risk factors for reported outcomes of patients with stroke (P<.05). Correlation analysis showed that serum triglyceride, total cholesterol, and low-density lipoprotein were negatively correlated with Stroke-PRO scores in patients with stroke (P<.05), while high-density lipoprotein was positively correlated with patients with stroke (P<.05). The 95% CI was -0.31 to -0.03 for triglyceride, 0.17-0.44 for high-density lipoprotein, -0.29 to -0.01 for cholesterol, -0.30 to -0.02 for low-density lipoprotein, and -0.12 to 0.16 for blood glucose. CONCLUSIONS: Patients with stroke have a low level of health, and their reported outcomes need to be improved. Accordingly, nursing staff should pay attention to the quality of life and blood lipid indexes of patients with stroke, actively assess their actual health status, and take early intervention measures to promote their recovery.


Asunto(s)
Medición de Resultados Informados por el Paciente , Calidad de Vida , Accidente Cerebrovascular , Humanos , Estudios Transversales , Femenino , Masculino , Persona de Mediana Edad , Accidente Cerebrovascular/psicología , Accidente Cerebrovascular/epidemiología , Anciano , Estudios Retrospectivos , Encuestas y Cuestionarios , China/epidemiología , Rehabilitación de Accidente Cerebrovascular
8.
ACS Appl Mater Interfaces ; 16(13): 16927-16935, 2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38506726

RESUMEN

Bismuth (Bi) exhibits a high theoretical capacity, excellent electrical conductivity properties, and remarkable interlayer spacing, making it an ideal electrode material for supercapacitors. However, during the charge and discharge processes, Bi is prone to volume expansion and pulverization, resulting in a decline in the capacitance. Deposition of a nonmetal on its surface is considered an effective way to modulate its morphology and electronic structure. Herein, we employed the chemical vapor deposition technique to fabricate Se-decorated Bi nanosheets on a nickel foam (NF) substrate. Various characterizations indicated that the deposition of Se on Bi nanosheets regulated their surface morphology and chemical state, while sustaining their pristine phase structure. Electrochemical tests demonstrated that Se-decorated Bi nanosheets exhibited a 51.1% improvement in capacity compared with pristine Bi nanosheets (1313 F/g compared to 869 F/g at a current density of 5 A/g). The energy density of the active material in an assembled asymmetric supercapacitor could reach 151.2 Wh/kg at a power density of 800 W/kg. These findings suggest that Se decoration is a promising strategy to enhance the capacity of the Bi nanosheets.

9.
Sci Total Environ ; 857(Pt 3): 159656, 2023 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-36280076

RESUMEN

As a special category of pesticides, chiral pesticides have increased the difficulty in investigating pesticide toxicity. Based on their usage, chiral pesticides can be divided into insecticides, herbicides, and fungicides. Over the past decades, great efforts have been made on elucidating their toxicological effects. However, no literature has reviewed the enantioselective toxicity of chiral pesticides since 2014. In recent years, more chiral pesticides have been registered for application. As such, huge research progresses have been achieved in enantioselective toxicity of chiral pesticides. Generally, more researches have remedied the knowledge gap in toxicological effects of old and new chiral pesticides. And the toxicological endpoints being evaluated have become more specific rather than centering on basic toxicity and target organisms. Besides, the underlying mechanisms accounting for the enantioselectivity in toxicological effects of chiral pesticides have been discussed as well. All in all, this review provides the critical knowledge for risk assessments, and help to drive the green-technology of single- or enriched-enantiomer pesticides and formulation of relevant laws and regulations.


Asunto(s)
Fungicidas Industriales , Herbicidas , Insecticidas , Plaguicidas , Plaguicidas/toxicidad , Estereoisomerismo , Fungicidas Industriales/toxicidad
10.
Nutrients ; 15(19)2023 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-37836523

RESUMEN

The gut microbiota is known to regulate the immune system and thereby influence susceptibility to infection. In this study, we observed that the administration of Enterococcus faecium HDRsEf1 (HDRsEf1) led to an improvement in the development of the immune system. This was evidenced by an increase in both the spleen index and the area of spleen white pulp. Specifically, the proportion of T helper (Th) 1 cells and the production of IFN-γ and IL-12 were significantly increased in the spleens of mice treated with HDRsEf1. In agreement with the in vivo results, we found that Th1-related cytokines, including IFN-γ and IL-12p70, were strongly induced in splenocytes treated with HDRsEf1. In addition, Th1 cell activation and high-level secretion of IL-12p70 were also confirmed by coculture of CD4+ T cells with bone marrow-derived dendritic cells treated with HDRsEf1. Moreover, the employment of HDRsEf1 was identified to augment resilience against systemic infection provoked by S. Typhimurium and stimulate the expression of the genes for TNFα and iNOS in the initial stage of infection, signifying that reinforced Th1 cells and IL-12 might activate macrophages for antibacterial safeguards. In summary, our study suggests that HDRsEf1 could act as an effective immunobiotic functional agent, promoting systemic Th1 immunological responses and priming defenses against infection.


Asunto(s)
Enterococcus faecium , Células Th2 , Ratones , Animales , Células TH1 , Citocinas/metabolismo , Interleucina-12/metabolismo
11.
ACS Appl Mater Interfaces ; 15(24): 29204-29213, 2023 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-37289091

RESUMEN

Hard carbons (HCs) have gained much attention for next-generation high energy density lithium-ion battery (LIB) anode candidates. However, voltage hysteresis, low rate capability, and large initial irreversible capacity severely affect their booming application. Herein, a general strategy is reported to fabricate heterogeneous atom (N/S/P/Se)-doped HC anodes with superb rate capability and cyclic stability based on a three-dimensional (3D) framework and a hierarchical porous structure. The obtained N-doped hard carbon (NHC) exhibits an excellent rate capability of 315 mA h g-1 at 10.0 A g-1 and a long-term cyclic stability of 90.3% capacity retention after 1000 cycles at 3 A g-1. Moreover, the as-constructed pouch cell delivers a high energy density of 483.8 W h kg-1 and fast charging capability. The underlying mechanisms of lithium storage are illustrated by electrochemical kinetic analysis and theoretical calculations. It is demonstrated that heteroatom doping imposes significant effects on adsorption and diffusion for Li+. The versatile strategy in this work opens an avenue for rational design of advanced carbonaceous materials with high performance for LIB applications.

12.
Phys Chem Chem Phys ; 14(43): 15021-8, 2012 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-23034581

RESUMEN

The driving mechanism of the metal-insulator transition (MIT) in VO(2) has always attracted attention, in particular with regards to understanding if and how the doping mechanism may tune the MIT transition temperature. However, due to the lack of detailed local structural information, in this oxide the underlying MIT mechanism is still matter of debate. In this contribution on the V(1-x)W(x)O(2) system, we attempt to clarify the origin of the MIT induced by tungsten doping. Combining W L(3)-edge and V K-edge extended X-ray absorption fine-structure (EXAFS) spectroscopy, the local structures around both V and W have been obtained. The data point out the occurrence of internal stress along the V-V chains induced by doping. It reaches a critical value that remains constant during the transition. The main effect of the internal stress on the vanadium local structure has also been identified. Actually, upon increasing the dopant concentration, the tilt of the V-V pairs towards the apex oxygen atoms in the VO(6) octahedron decreases while the V-V bond lengths remain unchanged. The electronic structure has also been investigated by O K-edge X-ray absorption near-edge structure (XANES) spectroscopy. Actually, at high doping concentrations the interaction of O(2p) and the V d(∥) state increases, while the hybridization of O(2p) and V π* decreases. The O(2p)-V(3d) hybridization is therefore an essential parameter correlated with the decreasing transition temperature in the V(1-x)W(x)O(2) system.

13.
Sci Rep ; 12(1): 9997, 2022 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-35705642

RESUMEN

Clonostachys chloroleuca 67-1 (formerly C. rosea 67-1) is a promising mycoparasite with great potential for controlling various plant fungal diseases. The mitogen-activated protein kinase (MAPK)-encoding gene Crmapk is of great importance to the mycoparasitism and biocontrol activities of C. chloroleuca. To investigate the molecular mechanisms underlying the role of Crmapk in mycoparasitism, a high-quality yeast two hybrid (Y2H) library of C. chloroleuca 67-1 was constructed, and proteins interacting with Crmapk were characterised. The library contained 1.6 × 107 independent clones with a recombination rate of 96%, and most inserted fragments were > 1 kb. The pGBKT7-Crmapk bait vector with no self-activation or toxicity to yeast cells was used to screen interacting proteins from the Y2H library, resulting in 60 candidates, many linked to metabolism, cellular processes and signal transduction. Combined bioinformatics and transcriptome analyses of C. chloroleuca 67-1 and ΔCrmapk mutant mycoparasitising Sclerotinia sclerotiorum sclerotia, 41 differentially expressed genes were identified, which might be the targets of the Fus3/Kss1-MAPK pathway. The results provide a profile of potential protein interactions associated with MAPK enzymes in mycoparasites, and are of great significance for understanding the mechanisms of Crmapk regulating C. chloroleuca mycoparasitism.


Asunto(s)
Hypocreales , Proteínas de Saccharomyces cerevisiae , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Hypocreales/genética , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Enfermedades de las Plantas/microbiología , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo
14.
J Fungi (Basel) ; 8(6)2022 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-35736050

RESUMEN

Clonostachys rosea is an important mycoparasite, with great potential for controlling numerous plant fungal diseases. Understanding the mechanisms and modes of action will assist the development and application of this biocontrol fungus. In this study, the highly efficient C. rosea 67-1 strain was marked with the green fluorescent protein (GFP), and the transformant possessed the same biological characteristics as the wild-type strain. Fungal interactions with Botrytis cinerea during co-culture and encounter on tomato leaves were assessed by fluorescence confocal and electron microscopy. The results indicated that once the two fungi met, the hyphae of C. rosea grew alongside those of B. cinerea, then attached tightly to the host and developed special structures, via which the biocontrol fungus penetrated the host and absorbed nutrients, eventually disintegrating the cells of the pathogen. Mycoparasitism to B. cinerea was also observed on tomato leaves, suggesting that C. rosea can colonize on plants and act following the invasion of the pathogenic fungus.

15.
Front Physiol ; 12: 626240, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33708138

RESUMEN

The Gansu zokor (Eospalax cansus) is a subterranean rodent species that is unique to China. These creatures inhabit underground burrows with a hypoxia environment. Metabolic energy patterns in subterranean rodents have become a recent focus of research; however, little is known about brain energy metabolism under conditions of hypoxia in this species. The mammalian (mechanistic) target of rapamycin complex 1 (mTORC1) coordinates eukaryotic cell growth and metabolism, and its downstream targets regulate hypoxia inducible factor-1α (HIF-1α) under conditions of hypoxia to induce glycolysis. In this study, we compared the metabolic characteristics of hypoxia-tolerant subterranean Gansu zokors under hypoxic conditions with those of hypoxia-intolerant Sprague-Dawley rats with a similar-sized surface area. We exposed Gansu zokors and rats to hypoxia I (44 h at 10.5% O2) or hypoxia II (6 h at 6.5% O2) and then measured the transcriptional levels of mTORC1 downstream targets, the transcriptional and translational levels of glycolysis-related genes, glucose and fructose levels in plasma and brain, and the activity of key glycolysis-associated enzymes. Under hypoxia, we found that hif-1α transcription was upregulated via the mTORC1/eIF4E pathway to drive glycolysis. Furthermore, Gansu zokor brain exhibited enhanced fructose-driven glycolysis under hypoxia through increased expression of the GLUT5 fructose transporter and ketohexokinase (KHK), in addition to increased KHK enzymatic activity, and utilization of fructose; these changes did not occur in rat. However, glucose-driven glycolysis was enhanced in both Gansu zokor and rat under hypoxia II of 6.5% O2 for 6 h. Overall, our results indicate that on the basis of glucose as the main metabolic substrate, fructose is used to accelerate the supply of energy in Gansu zokor, which mirrors the metabolic responses to hypoxia in this species.

16.
Nanoscale ; 11(16): 7857-7865, 2019 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-30964505

RESUMEN

In this paper, two kinds of two-dimensional manganese boride monolayers, h-MnB2 and t-MnB2, are predicted to be stable metallic nanosheets, which exhibit favorable mechanical and thermal properties. The Young's moduli of h-MnB2 and t-MnB2 are 77.73 N m-1 and 59.59 N m-1, respectively. Ab initio molecular dynamics results show that h-MnB2 and t-MnB2 can sustain up to 500 K and 1000 K, respectively. The magnetic property of h-MnB2 is frustrated antiferromagnetic with a Néel temperature of about 25 K, and the magnetic property of t-MnB2 is collinear antiferromagnetic with a Néel temperature of about 317 K. In addition, the electronic structure of the h-MnB2 monolayer can be tuned by passivation to exhibit Dirac states. h-MnB2 can also self-assemble to form nanotubes, and is thus very promising for application as the anode for Li-ion batteries because of its high capacity (about 875 mA h g-1), low diffusion barrier (about 0.03 eV) and strong stability.

17.
RSC Adv ; 8(34): 19151-19156, 2018 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-35539638

RESUMEN

Vanadium dioxide (VO2) material shows a distinct metal-insulator transition (MIT) at the critical temperature of ∼340 K. Similar to other correlated oxides, the MIT properties of VO2 is always sensitive to those crystal defects such as oxygen vacancies. In this study, we investigated the oxygen vacancies related phase transition behavior of VO2 crystal film and systematically examined the effect of oxygen vacancies from the optical constant measurements. The results indicated that the oxygen vacancies changed not only the electron occupancy on V 3d-O 2p hybrid-orbitals, but also the electron-electron correlation energy and the related band gap, which modulated the MIT behavior and decreased the critical temperature resultantly. Our work not only provided a facile way to modulate the MIT behavior of VO2 crystal film, but also revealed the effects of the oxygen vacancies on the electronic inter-band transitions as well as the electronic correlations in driving this MIT process.

18.
ACS Appl Mater Interfaces ; 8(48): 32971-32977, 2016 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-27934180

RESUMEN

In this work, high-quality VO2 epitaxial films were prepared on high-conductivity n-GaN (0001) crystal substrates via an oxide molecular beam epitaxy method. By fabricating a two-terminal VO2/GaN film device, we observed that the infrared transmittance and resistance of VO2 films could be dynamically controlled by an external bias voltage. Based on the hysteretic switching effect of VO2 in infrared range, an optoelectronic memory device was achieved. This memory device was operated under the "electrical writing-optical reading" mode, which shows promising applications in VO2-based optoelectronic device in the future.

19.
Sci Rep ; 5: 9328, 2015 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-25950809

RESUMEN

The mechanism for regulating the critical temperature (TC) of metal-insulator transition (MIT) in ions-doped VO2 systems is still a matter of debate, in particular, the unclear roles of lattice distortion and charge doping effects. To rule out the charge doping effect on the regulation of TC, we investigated Ti(4+)-doped VO2 (Ti(x)V(1-x)O2) system. It was observed that the TC of Ti(x)V(1-x)O2 samples first slightly decreased and then increased with increasing Ti concentration. X-ray absorption fine structure (XAFS) spectroscopy was used to explore the electronic states and local lattice structures around both Ti and V atoms in Ti(x)V(1-x)O2 samples. Our results revealed the local structure evolution from the initial anatase to the rutile-like structure around the Ti dopants. Furthermore, the host monoclinic VO2 lattice, specifically, the VO6 octahedra would be subtly distorted by Ti doping. The distortion of VO6 octahedra and the variation of TC showed almost the similar trend, confirming the direct effect of local structural perturbations on the phase transition behavior. By comparing other ion-doping systems, we point out that the charge doping is more effective than the lattice distortion in modulating the MIT behavior of VO2 materials.

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